Flue gas desulfurization method and apparatus

DOEpatents

Madden, D.A.; Farthing, G.A.

1998-09-29

A combined furnace limestone injection and dry scrubber flue gas desulfurization (FGD) system collects solids from the flue gas stream in first particulate collection device located downstream of an outlet of a convection pass of the furnace and upstream of the dry scrubber. The collected solids are diverted to the dry scrubber feed slurry preparation system to increase sulfur oxide species removal efficiency and sorbent utilization. The level of lime in the feed slurry provided to the dry scrubber is thus increased, which enhances removal of sulfur oxide species in the dry scrubber. The decreased particulate loading to the dry scrubber helps maintain a desired degree of free moisture in the flue gas stream entering the dry scrubber, which enhances sulfur oxide species removal both in the dry scrubber and downstream particulate collector, normally a baghouse. 5 figs.

The Research Process on Converter Steelmaking Process by Using Limestone

NASA Astrophysics Data System (ADS)

Tang, Biao; Li, Xing-yi; Cheng, Han-chi; Wang, Jing; Zhang, Yun-long

2017-08-01

Compared with traditional converter steelmaking process, steelmaking process with limestone uses limestone to replace lime partly. A lot of researchers have studied about the new steelmaking process. There are much related research about material balance calculation, the behaviour of limestone in the slag, limestone powder injection in converter and application of limestone in iron and steel enterprises. The results show that the surplus heat of converter can meet the need of the limestone calcination, and the new process can reduce the steelmaking process energy loss in the whole steelmaking process, reduce carbon dioxide emissions, and improve the quality of the gas.

Pressurized fluidized-bed hydroretorting of Eastern oil shales -- Sulfur control. Topical report for Subtask 3.1, In-bed sulfur capture tests; Subtask 3.2, Electrostatic desulfurization; Subtask 3.3, Microbial desulfurization and denitrification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roberts, M.J.; Abbasian, J.; Akin, C.

1992-05-01

This topical report on ``Sulfur Control`` presents the results of work conducted by the Institute of Gas Technology (IGT), the Illinois Institute of Technology (IIT), and the Ohio State University (OSU) to develop three novel approaches for desulfurization that have shown good potential with coal and could be cost-effective for oil shales. These are (1) In-Bed Sulfur Capture using different sorbents (IGT), (2) Electrostatic Desulfurization (IIT), and (3) Microbial Desulfurization and Denitrification (OSU and IGT). The objective of the task on In-Bed Sulfur Capture was to determine the effectiveness of different sorbents (that is, limestone, calcined limestone, dolomite, and siderite)more » for capturing sulfur (as H{sub 2}S) in the reactor during hydroretorting. The objective of the task on Electrostatic Desulfurization was to determine the operating conditions necessary to achieve a high degree of sulfur removal and kerogen recovery in IIT`s electrostatic separator. The objectives of the task on Microbial Desulfurization and Denitrification were to (1) isolate microbial cultures and evaluate their ability to desulfurize and denitrify shale, (2) conduct laboratory-scale batch and continuous tests to improve and enhance microbial removal of these components, and (3) determine the effects of processing parameters, such as shale slurry concentration, solids settling characteristics, agitation rate, and pH on the process.« less

Continuous magnetic separator and process

DOEpatents

Oder, Robin R.; Jamison, Russell E.

2008-04-22

A continuous magnetic separator and process for separating a slurry comprising magnetic particles into a clarified stream and a thickened stream. The separator has a container with a slurry inlet, an overflow outlet for the discharge of the clarified slurry stream, and an underflow outlet for the discharge of a thickened slurry stream. Magnetic particles in the slurry are attracted to, and slide down, magnetic rods within the container. The slurry is thus separated into magnetic concentrate and clarified slurry. Flow control means can be used to control the ratio of the rate of magnetic concentrate to the rate of clarified slurry. Feed control means can be used to control the rate of slurry feed to the slurry inlet.

Method for enhanced atomization of liquids

DOEpatents

Thompson, Richard E.; White, Jerome R.

1993-01-01

In a process for atomizing a slurry or liquid process stream in which a slurry or liquid is passed through a nozzle to provide a primary atomized process stream, an improvement which comprises subjecting the liquid or slurry process stream to microwave energy as the liquid or slurry process stream exits the nozzle, wherein sufficient microwave heating is provided to flash vaporize the primary atomized process stream.

Combined on-board hydride slurry storage and reactor system and process for hydrogen-powered vehicles and devices

DOEpatents

Brooks, Kriston P; Holladay, Jamelyn D; Simmons, Kevin L; Herling, Darrell R

2014-11-18

An on-board hydride storage system and process are described. The system includes a slurry storage system that includes a slurry reactor and a variable concentration slurry. In one preferred configuration, the storage system stores a slurry containing a hydride storage material in a carrier fluid at a first concentration of hydride solids. The slurry reactor receives the slurry containing a second concentration of the hydride storage material and releases hydrogen as a fuel to hydrogen-power devices and vehicles.

Powder treatment process

DOEpatents

Weyand, J.D.

1988-02-09

Disclosed are: (1) a process comprising spray drying a powder-containing slurry, the slurry containing a powder constituent susceptible of oxidizing under the temperature conditions of the spray drying, while reducing the tendency for oxidation of the constituent by including as a liquid constituent of the slurry an organic liquid; (2) a process comprising spray drying a powder-containing slurry, the powder having been pretreated to reduce content of a powder constituent susceptible of oxidizing under the temperature conditions of the spray drying, the pretreating comprising heating the powder to react the constituent; and (3) a process comprising reacting ceramic powder, grinding the reacted powder, slurrying the ground powder, spray drying the slurried powder, and blending the dried powder with metal powder. 2 figs.

Powder treatment process

DOEpatents

Weyand, John D.

1988-01-01

(1) A process comprising spray drying a powder-containing slurry, the slurry containing a powder constituent susceptible of oxidizing under the temperature conditions of the spray drying, while reducing the tendency for oxidation of the constituent by including as a liquid constituent of the slurry an organic liquid; (2) a process comprising spray drying a powder-containing slurry, the powder having been pretreated to reduce content of a powder constituent susceptible of oxidizing under the temperature conditions of the spray drying, the pretreating comprising heating the powder to react the constituent; and (3) a process comprising reacting ceramic powder, grinding the reacted powder, slurrying the ground powder, spray drying the slurried powder, and blending the dried powder with metal powder.

Method and apparatus for improved wire saw slurry

DOEpatents

Costantini, Michael A.; Talbott, Jonathan A.; Chandra, Mohan; Prasad, Vishwanath; Caster, Allison; Gupta, Kedar P.; Leyvraz, Philippe

2000-09-05

A slurry recycle process for use in free-abrasive machining operations such as for wire saws used in wafer slicing of ingots, where the used slurry is separated into kerf-rich and abrasive-rich components, and the abrasive-rich component is reconstituted into a makeup slurry. During the process, the average particle size of the makeup slurry is controlled by monitoring the condition of the kerf and abrasive components and making necessary adjustments to the separating force and dwell time of the separator apparatus. Related pre-separator and post separator treatments, and feedback of one or the other separator slurry output components for mixing with incoming used slurry and recirculation through the separator, provide further effectiveness and additional control points in the process. The kerf-rich component is eventually or continually removed; the abrasive-rich component is reconstituted into a makeup slurry with a controlled, average particle size such that the products of the free-abrasive machining method using the recycled slurry process of the invention are of consistent high quality with less TTV deviation from cycle to cycle for a prolonged period or series of machining operations.

Coal liquefaction process

DOEpatents

Karr, Jr., Clarence

1977-04-19

An improved coal liquefaction process is provided which enables conversion of a coal-oil slurry to a synthetic crude refinable to produce larger yields of gasoline and diesel oil. The process is characterized by a two-step operation applied to the slurry prior to catalytic desulfurization and hydrogenation in which the slurry undergoes partial hydrogenation to crack and hydrogenate asphaltenes and the partially hydrogenated slurry is filtered to remove minerals prior to subsequent catalytic hydrogenation.

Precipitate hydrolysis process for the removal of organic compounds from nuclear waste slurries

DOEpatents

Doherty, Joseph P.; Marek, James C.

1989-01-01

A process for removing organic compounds from a nuclear waste slurry comprising reacting a mixture of radioactive waste precipitate slurry and an acid in the presence of a catalytically effective amount of a copper (II) catalyst whereby the organic compounds in the precipitate slurry are hydrolyzed to form volatile organic compounds which are separated from the reacting mixture. The resulting waste slurry, containing less than 10 percent of the orginal organic compounds, is subsequently blended with high level radioactive sludge and transferred to a virtrification facility for processing into borosilicate glass for long-term storage.

The use of additive ceramic hollow spheres on cement slurry to prevent lost circulation in formation `X' having low pressure fracture

NASA Astrophysics Data System (ADS)

Rita, Novia; Mursyidah, Syahindra, Michael

2018-03-01

When drilling, if the hydrostatic pressure is higher than formation pressure (fracture pressure) it will cause lost circulation during cementing process. To solve this problem, hydrostatic pressure of slurry can be decreased by lowering the slurry density by using some additives. Ceramic Hollow Spheres (CHS) is lightweight additive. This additive comes with low specific gravity so it can lowered the slurry density. When the low-density slurry used in cementing process, it can prevent low circulation and fractured formation caused by cement itself. Class G cement is used in this experiment with the standard density of this slurry is 15.8 ppg. With the addition of CHS, slurry density lowered to 12.5 ppg. CHS not only used to lower the slurry density, it also used to make the same properties with the standard slurry even the density has been lowered. Both thickening time and compressive strength have not change if the CHS added to the slurry. With addition of CHS, thickening time at 70 Bc reached in 03 hours 12 minutes. For the compressive strength, 2000 psi reached in 07 hours 07 minutes. Addition of CHS can save more time in cementing process of X formation.

Fused slurry silicide coatings for columbium alloy reentry heat shields. Volume 2: Experimental and coating process details

NASA Technical Reports Server (NTRS)

Fitzgerald, B.

1973-01-01

The experimental and coating process details are presented. The process specifications which were developed for the formulation and application of the R-512E fused slurry silicide coating using either an acrylic or nitrocellulose base slurry system is also discussed.

Precipitate hydrolysis process for the removal of organic compounds from nuclear waste slurries

DOEpatents

Doherty, J.P.; Marek, J.C.

1987-02-25

A process for removing organic compounds from a nuclear waste slurry comprising reacting a mixture of radioactive waste precipitate slurry and an acid in the presence of a catalytically effective amount of a copper(II) catalyst whereby the organic compounds in the precipitate slurry are hydrolyzed to form volatile organic compounds which are separated from the reacting mixture. The resulting waste slurry, containing less than 10 percent of the original organic compounds, is subsequently blended with high level radioactive sludge land transferred to a vitrification facility for processing into borosilicate glass for long-term storage. 2 figs., 3 tabs.

Research on numerical simulation and protection of transient process in long-distance slurry transportation pipelines

NASA Astrophysics Data System (ADS)

Lan, G.; Jiang, J.; Li, D. D.; Yi, W. S.; Zhao, Z.; Nie, L. N.

2013-12-01

The calculation of water-hammer pressure phenomenon of single-phase liquid is already more mature for a pipeline of uniform characteristics, but less research has addressed the calculation of slurry water hammer pressure in complex pipelines with slurry flows carrying solid particles. In this paper, based on the developments of slurry pipelines at home and abroad, the fundamental principle and method of numerical simulation of transient processes are presented, and several boundary conditions are given. Through the numerical simulation and analysis of transient processes of a practical engineering of long-distance slurry transportation pipeline system, effective protection measures and operating suggestions are presented. A model for calculating the water impact of solid and fluid phases is established based on a practical engineering of long-distance slurry pipeline transportation system. After performing a numerical simulation of the transient process, analyzing and comparing the results, effective protection measures and operating advice are recommended, which has guiding significance to the design and operating management of practical engineering of longdistance slurry pipeline transportation system.

Process to remove actinides from soil using magnetic separation

DOEpatents

Avens, Larry R.; Hill, Dallas D.; Prenger, F. Coyne; Stewart, Walter F.; Tolt, Thomas L.; Worl, Laura A.

1996-01-01

A process of separating actinide-containing components from an admixture including forming a slurry including actinide-containing components within an admixture, said slurry including a dispersion-promoting surfactant, adjusting the pH of the slurry to within a desired range, and, passing said slurry through a pretreated matrix material, said matrix material adapted to generate high magnetic field gradients upon the application of a strong magnetic field exceeding about 0.1 Tesla whereupon a portion of said actinide-containing components are separated from said slurry and remain adhered upon said matrix material is provided.

Multi-stage slurry system used for grinding and polishing materials

DOEpatents

Hed, P. Paul; Fuchs, Baruch A.

2001-01-01

A slurry system draws slurry from a slurry tank via one of several intake pipes, where each pipe has an intake opening at a different depth in the slurry. The slurry is returned to the slurry tank via a bypass pipe in order to continue the agitation of the slurry. The slurry is then diverted to a delivery pipe, which supplies slurry to a polisher. The flow of slurry in the bypass pipe is stopped in order for the slurry in the slurry tank to begin to settle. As the polishing continues, slurry is removed from shallower depths in order to pull finer grit from the slurry. When the polishing is complete, the flow in the delivery pipe is ceased. The flow of slurry in the bypass pipe is resumed to start agitating the slurry. In another embodiment, the multiple intake pipes are replaced by a single adjustable pipe. As the slurry is settling, the pipe is moved upward to remove the finer grit near the top of the slurry tank as the polishing process continues.

A low-cost solid–liquid separation process for enzymatically hydrolyzed corn stover slurries

DOE PAGES

Sievers, David A.; Lischeske, James J.; Biddy, Mary J.; ...

2015-07-01

Solid-liquid separation of intermediate process slurries is required in some process configurations for the conversion of lignocellulosic biomass to transportation fuels. Thermochemically pretreated and enzymatically hydrolyzed corn stover slurries have proven difficult to filter due to formation of very low permeability cakes that are rich in lignin. Treatment of two different slurries with polyelectrolyte flocculant was demonstrated to increase mean particle size and filterability. Filtration flux was greatly improved, and thus scaled filter unit capacity was increased approximately 40-fold compared with unflocculated slurry. Although additional costs were accrued using polyelectrolyte, techno-economic analysis revealed that the increase in filter capacity significantlymore » reduced overall production costs. Fuel production cost at 95% sugar recovery was reduced by $1.35 US per gallon gasoline equivalent for dilute-acid pretreated and enzymatically hydrolyzed slurries and $3.40 for slurries produced using an additional alkaline de-acetylation preprocessing step that is even more difficult to natively filter.« less

Aluminum phosphate ceramics for waste storage

DOEpatents

Wagh, Arun; Maloney, Martin D

2014-06-03

The present disclosure describes solid waste forms and methods of processing waste. In one particular implementation, the invention provides a method of processing waste that may be particularly suitable for processing hazardous waste. In this method, a waste component is combined with an aluminum oxide and an acidic phosphate component in a slurry. A molar ratio of aluminum to phosphorus in the slurry is greater than one. Water in the slurry may be evaporated while mixing the slurry at a temperature of about 140-200.degree. C. The mixed slurry may be allowed to cure into a solid waste form. This solid waste form includes an anhydrous aluminum phosphate with at least a residual portion of the waste component bound therein.

Hydrogen Production in Radioactive Solutions in the Defense Waste Processing Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

CRAWFORD, CHARLES L.

2004-05-26

In the radioactive slurries and solutions to be processed in the Defense Waste Processing Facility (DWPF), hydrogen will be produced continuously by radiolysis. This production results from alpha, beta, and gamma rays from decay of radionuclides in the slurries and solutions interacting with the water. More than 1000 research reports have published data concerning this radiolytic production. The results of these studies have been reviewed in a comprehensive monograph. Information about radiolytic hydrogen production from the different process tanks is necessary to determine air purge rates necessary to prevent flammable mixtures from accumulating in the vapor spaces above these tanks.more » Radiolytic hydrogen production rates are usually presented in terms of G values or molecules of hydrogen produced per 100ev of radioactive decay energy absorbed by the slurry or solution. With the G value for hydrogen production, G(H2), for a particular slurry and the concentrations of radioactive species in that slurry, the rate of H2 production for that slurry can be calculated. An earlier investigation estimated that the maximum rate that hydrogen could be produced from the sludge slurry stream to the DWPF is with a G value of 0.45 molecules per 100ev of radioactive decay energy sorbed by the slurry.« less

Process for blending coal with water immiscible liquid

DOEpatents

Heavin, Leonard J.; King, Edward E.; Milliron, Dennis L.

1982-10-26

A continuous process for blending coal with a water immiscible liquid produces a uniform, pumpable slurry. Pulverized raw feed coal and preferably a coal derived, water immiscible liquid are continuously fed to a blending zone (12 and 18) in which coal particles and liquid are intimately admixed and advanced in substantially plug flow to form a first slurry. The first slurry is withdrawn from the blending zone (12 and 18) and fed to a mixing zone (24) where it is mixed with a hot slurry to form the pumpable slurry. A portion of the pumpable slurry is continuously recycled to the blending zone (12 and 18) for mixing with the feed coal.

Bed morphological features associated with an optimal slurry concentration for reproducible preparation of efficient capillary ultrahigh pressure liquid chromatography columns.

PubMed

Reising, Arved E; Godinho, Justin M; Jorgenson, James W; Tallarek, Ulrich

2017-06-30

Column wall effects and the formation of larger voids in the bed during column packing are factors limiting the achievement of highly efficient columns. Systematic variation of packing conditions, combined with three-dimensional bed reconstruction and detailed morphological analysis of column beds, provide valuable insights into the packing process. Here, we study a set of sixteen 75μm i.d. fused-silica capillary columns packed with 1.9μm, C18-modified, bridged-ethyl hybrid silica particles slurried in acetone to concentrations ranging from 5 to 200mg/mL. Bed reconstructions for three of these columns (representing low, optimal, and high slurry concentrations), based on confocal laser scanning microscopy, reveal morphological features associated with the implemented slurry concentration, that lead to differences in column efficiency. At a low slurry concentration, the bed microstructure includes systematic radial heterogeneities such as particle size-segregation and local deviations from bulk packing density near the wall. These effects are suppressed (or at least reduced) with higher slurry concentrations. Concomitantly, larger voids (relative to the mean particle diameter) begin to form in the packing and increase in size and number with the slurry concentration. The most efficient columns are packed at slurry concentrations that balance these counteracting effects. Videos are taken at low and high slurry concentration to elucidate the bed formation process. At low slurry concentrations, particles arrive and settle individually, allowing for rearrangements. At high slurry concentrations, they arrive and pack as large patches (reflecting particle aggregation in the slurry). These processes are discussed with respect to column packing, chromatographic performance, and bed microstructure to help reinforce general trends previously described. Conclusions based on this comprehensive analysis guide us towards further improvement of the packing process. Copyright © 2017 Elsevier B.V. All rights reserved.

DEMONSTRATION BULLETIN: SLURRY BIODEGRADATION, International Technology Corporation

EPA Science Inventory

This technology uses a slurry-phase bioreactor in which the soil is mixed with water to form a slurry. Microorganisms and nutrients are added to the slurry to enhance the biodegradation process, which converts organic wastes into relatively harmless byproducts of microbial metabo...

Chemical Hydride Slurry for Hydrogen Production and Storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

McClaine, Andrew W

2008-09-30

The purpose of this project was to investigate and evaluate the attractiveness of using a magnesium chemical hydride slurry as a hydrogen storage, delivery, and production medium for automobiles. To fully evaluate the potential for magnesium hydride slurry to act as a carrier of hydrogen, potential slurry compositions, potential hydrogen release techniques, and the processes (and their costs) that will be used to recycle the byproducts back to a high hydrogen content slurry were evaluated. A 75% MgH 2 slurry was demonstrated, which was just short of the 76% goal. This slurry is pumpable and storable for months at amore » time at room temperature and pressure conditions and it has the consistency of paint. Two techniques were demonstrated for reacting the slurry with water to release hydrogen. The first technique was a continuous mixing process that was tested for several hours at a time and demonstrated operation without external heat addition. Further work will be required to reduce this design to a reliable, robust system. The second technique was a semi-continuous process. It was demonstrated on a 2 kWh scale. This system operated continuously and reliably for hours at a time, including starts and stops. This process could be readily reduced to practice for commercial applications. The processes and costs associated with recycling the byproducts of the water/slurry reaction were also evaluated. This included recovering and recycling the oils of the slurry, reforming the magnesium hydroxide and magnesium oxide byproduct to magnesium metal, hydriding the magnesium metal with hydrogen to form magnesium hydride, and preparing the slurry. We found that the SOM process, under development by Boston University, offers the lowest cost alternative for producing and recycling the slurry. Using the H2A framework, a total cost of production, delivery, and distribution of $4.50/kg of hydrogen delivered or $4.50/gge was determined. Experiments performed at Boston University have demonstrated the technical viability of the process and have provided data for the cost analyses that have been performed. We also concluded that a carbothermic process could also produce magnesium at acceptable costs. The use of slurry as a medium to carry chemical hydrides has been shown during this project to offer significant advantages for storing, delivering, and distributing hydrogen: • Magnesium hydride slurry is stable for months and pumpable. • The oils of the slurry minimize the contact of oxygen and moisture in the air with the metal hydride in the slurry. Thus reactive chemicals, such as lithium hydride, can be handled safely in the air when encased in the oils of the slurry. • Though magnesium hydride offers an additional safety feature of not reacting readily with water at room temperatures, it does react readily with water at temperatures above the boiling point of water. Thus when hydrogen is needed, the slurry and water are heated until the reaction begins, then the reaction energy provides heat for more slurry and water to be heated. • The reaction system can be relatively small and light and the slurry can be stored in conventional liquid fuel tanks. When transported and stored, the conventional liquid fuel infrastructure can be used. • The particular metal hydride of interest in this project, magnesium hydride, forms benign byproducts, magnesium hydroxide (“Milk of Magnesia”) and magnesium oxide. • We have estimated that a magnesium hydride slurry system (including the mixer device and tanks) could meet the DOE 2010 energy density goals. During the investigation of hydriding techniques, we learned that magnesium hydride in a slurry can also be cycled in a rechargeable fashion. Thus, magnesium hydride slurry can act either as a chemical hydride storage medium or as a rechargeable hydride storage system. Hydrogen can be stored and delivered and then stored again thus significantly reducing the cost of storing and delivering hydrogen. Further evaluation and development of this concept will be performed as follow-on work under another project. However, since the cost of reducing magnesium from magnesium oxide makes up 85% of the cost of the slurry, if hydrogen can be stored many times in the slurry, then the cost of storing hydrogen can be spread over many units of hydrogen and can be significantly reduced from the costs of a chemical hydride system. This may be the most important finding of this project. If the slurry is used to carry a rechargeable hydride, the slurry can be stored in a conventional liquid fuel tank and delivered to a release system as hydrogen is needed. The release system will contain only the hydride needed to produce the hydrogen desired. This is in contrast to conventional designs proposed for other rechargeable hydride systems that store all the hydride in a large and heavy pressure and heat transfer vessel.« less

Effect of Surface-active Additives on Physical Properties of Slurries of Vapor-process Magnesium

NASA Technical Reports Server (NTRS)

Pinns, Murray L

1955-01-01

The presence of 3 to 5 percent surface-active additive gave the lowest Brookfield apparent viscosity, plastic viscosity, and yield value that were obtained for slurry fuels containing approximately 50 percent vapor-process magnesium in JP-1 fuel. The slurries settled little and were easily remixed. A polyoxyethylene dodecyl alcohol was the most effective of 13 additives tested in reducing the Brookfield apparent viscosity and the yield value of the slurry. The seven most effective additives all had a hydroxyl group plus an ester or polyoxethylene group in the molecule. The densities of some of the slurries were measured.

Effect of adding palm oil mill decanter cake slurry with regular turning operation on the composting process and quality of compost from oil palm empty fruit bunches.

PubMed

Yahya, Azmi; Sye, Chong Puay; Ishola, Tajudeen Abiodun; Suryanto, Hadi

2010-11-01

Formation of compost from oil palm empty fruit bunches (EFB) and decanter cake slurry by adding palm oil mill effluent (POME) with regular turning operation was investigated. The experiment was conducted in a commercial composting plant under the normal production process. The addition of decanter cake slurry has hastened the composting process of the EFB. The C/N ratio after 51 days for the mature compost with the decanter cake slurry was 18.65 while that of the matured compost without the decanter cake slurry remained high at 28.96. The compost formed from the addition of decanter cake to EFB and POME had 46.4% nitrogen, 17.9% phosphorus, 17.7% potassium and 23.1% calcium more than that without decanter cake. The use of compost produced from EFB, POME and decanter cake slurry could solve more environmental problems and enhance economic benefits in the oil palm industry.

Analysis and design of a calcium-based sulfur sorbent for applications in integrated gasification combined cycle energy systems

NASA Astrophysics Data System (ADS)

Hasler, David Johann Ludwig

The reactivity of various Ca-based sorbent materials in pelletized form with H2S or CO2 was investigated at high temperatures (750--880°C). An extensive study was conducted to compare the performance of sorbent pellets derived from plaster of Paris and limestone. Multicycle absorption and regeneration tests showed that plaster-based pellets out performed the limestone-based pellets primarily due to a higher surface area and mesoporosity. The effect of pore-modifiers on the reactivity of limestone with H 2S was investigated by incorporating additives such as cornstarch, graphite and polyvinylalcohol (PVA) in the sorbent. Multicycle sulfidation and regeneration tests of the modified sorbent showed that starch did not improve the reactivity of the limestone, graphite reduced the reactivity, while PVA improved it. The effect of the chemical additives MgO and SrO on the performance of CaO-based sorbent pellets was investigated. The effect of MgO was tested by starting with materials that contained MgCO3 in a natural form, such as dolomite. The effect of SrO was tested by starting with SrCO 3 either co-precipitated with CaCO3 or by wet-mixing SrCO 3 with limestone in slurry form. The MgO was found to improve the thermal stability of the CaO-based sorbent but lowered the overall absorption capacity of the material when reacted with CO2 or H2S, while SrO decreased the thermal stability of the sorbent when it was reacted with CO2; no absorption tests were run with H2S. A study of the performance of pelletized CaO-based cores coated with a refractory material such as alumina and limestone or alumina and kaolin was conducted. The reactivity of the core and shell pellets with H2S was determined. The strength and durability of the pellets were determined by using crushing strength analysis and abrasion resistance tests. Pellets coated with either alumina and limestone or alumina and kaolin proved to be strong and adequate for use in industrial reactors. A semi-empirical mathematical model was developed to represent the reaction of H2S with a sorbent pellet. The model was based on the well-known shrinking core model and it was applied successfully for the analysis of both pellet cores and core and shell pellets reacting with H2S.

Ethanol extraction of phytosterols from corn fiber

DOEpatents

Abbas, Charles; Beery, Kyle E.; Binder, Thomas P.; Rammelsberg, Anne M.

2010-11-16

The present invention provides a process for extracting sterols from a high solids, thermochemically hydrolyzed corn fiber using ethanol as the extractant. The process includes obtaining a corn fiber slurry having a moisture content from about 20 weight percent to about 50 weight percent solids (high solids content), thermochemically processing the corn fiber slurry having high solids content of 20 to 50% to produce a hydrolyzed corn fiber slurry, dewatering the hydrolyzed corn fiber slurry to achieve a residual corn fiber having a moisture content from about 30 to 80 weight percent solids, washing the residual corn fiber, dewatering the washed, hydrolyzed corn fiber slurry to achieve a residual corn fiber having a moisture content from about 30 to 80 weight percent solids, and extracting the residual corn fiber with ethanol and separating at least one sterol.

Performance and techno-economic assessment of several solid-liquid separation technologies for processing dilute-acid pretreated corn stover.

PubMed

Sievers, David A; Tao, Ling; Schell, Daniel J

2014-09-01

Solid-liquid separation of pretreated lignocellulosic biomass slurries is a critical unit operation employed in several different processes for production of fuels and chemicals. An effective separation process achieves good recovery of solute (sugars) and efficient dewatering of the biomass slurry. Dilute acid pretreated corn stover slurries were subjected to pressure and vacuum filtration and basket centrifugation to evaluate the technical and economic merits of these technologies. Experimental performance results were used to perform detailed process simulations and economic analysis using a 2000 tonne/day biorefinery model to determine differences between the various filtration methods and their process settings. The filtration processes were able to successfully separate pretreated slurries into liquor and solid fractions with estimated sugar recoveries of at least 95% using a cake washing process. A continuous vacuum belt filter produced the most favorable process economics. Copyright © 2014 Elsevier Ltd. All rights reserved.

Kinematical and mechanical aspects of wafer slicing

NASA Technical Reports Server (NTRS)

Werner, P. G.

1982-01-01

Some recently achieved results concerning the technological fundamentals of slurry sawing are presented. The specific material removal process and the related kinematic and geometric contact conditions between workpiece and saw blade are described. The result of a functional description of the slurry sawing process is presented, expressing the main process criteria, such as infeed per stroke, specific removal rate, specific tool wear, and vertical stroke intensity, in terms of the dominating process parameters, such as stroke length, width of workpiece, stroke frequency, specific cutting force and slurry specification.

A comprehensive evaluation of the influence of air combustion and oxy-fuel combustion flue gas constituents on Hg(0) re-emission in WFGD systems.

PubMed

Ochoa-González, Raquel; Díaz-Somoano, Mercedes; Martínez-Tarazona, M Rosa

2014-07-15

This paper evaluates the influence of the main constituents of flue gases from coal combustion (CO2, O2, N2 and water vapor), in air and oxy-fuel combustion conditions on the re-emission of Hg(0) in wet scrubbers. It was observed that the concentration of water vapor does not affect the re-emission of mercury, whereas O2 and CO2 have a notable influence. High concentrations of O2 in the flue gas prevent the re-emission of Hg(0) due to the reaction of oxygen with the metals present in low oxidation states. High concentrations of CO2, which cause a decrease in the pH and the redox potential of gypsum slurries, reduce the amount of Hg(0) that is re-emitted. As a consequence, the high content of CO2 in oxy-fuel combustion may decrease the re-emission of Hg(0) due to the solubility of CO2 in the suspension and the decrease in the pH. It was also found that O2 affects the stabilization of Hg(2+) species in gypsum slurries. The results of this study confirm that the amount of metals present in limestone as well as the redox potential and pH of the slurries in wet desulphurization plants need to be strictly controlled to reduce Hg(0) re-emissions from power plants operating under oxy-fuel combustion conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

Slip casting nano-particle powders for making transparent ceramics

DOEpatents

Kuntz, Joshua D [Livermore, CA; Soules, Thomas F [Livermore, CA; Landingham, Richard Lee [Livermore, CA; Hollingsworth, Joel P [Oakland, CA

2011-04-12

A method of making a transparent ceramic including the steps of providing nano-ceramic powders in a processed or unprocessed form, mixing the powders with de-ionized water, the step of mixing the powders with de-ionized water producing a slurry, sonifing the slurry to completely wet the powder and suspend the powder in the de-ionized water, separating very fine particles from the slurry, molding the slurry, and curing the slurry to produce the transparent ceramic.

Coal liquefaction process utilizing coal/CO.sub.2 slurry feedstream

DOEpatents

Comolli, Alfred G.; McLean, Joseph B.

1989-01-01

A coal hydrogenation and liquefaction process in which particulate coal feed is pressurized to an intermediate pressure of at least 500 psig and slurried with CO.sub.2 liquid to provide a flowable coal/CO.sub.2 slurry feedstream, which is further pressurized to at least 1000 psig and fed into a catalytic reactor. The coal particle size is 50-375 mesh (U.S. Sieve Series) and provides 50-80 W % coal in the coal/CO.sub.2 slurry feedstream. Catalytic reaction conditions are maintained at 650.degree.-850.degree. F. temperature, 1000-4000 psig hydrogen partial pressure and coal feed rate of 10-100 lb coal/hr ft.sup.3 reactor volume to produce hydrocarbon gas and liquid products. The hydrogen and CO.sub.2 are recovered from the reactor effluent gaseous fraction, hydrogen is recycled to the catalytic reactor, and CO.sub.2 is liquefied and recycled to the coal slurrying step. If desired, two catalytic reaction stages close coupled together in series relation can be used. The process advantageously minimizes the recycle and processing of excess hydrocarbon liquid previously needed for slurrying the coal feed to the reactor(s).

Effect of calcium formate as an additive on desulfurization in power plants.

PubMed

Li, Zhenhua; Xie, Chunfang; Lv, Jing; Zhai, Ruiguo

2018-05-01

SO 2 in flue gas needs to be eliminated to alleviate air pollution. As the quality of coal decreases and environmental standard requirements become more stringent, the high-efficiency desulfurization of flue gas faces more and more challenges. As an economical and environmentally friendly solution, the effect of calcium formate as an additive on desulfurization efficiency in the wet flue gas desulfurization (WFGD) process was studied for the first time. Improvement of the desulfurization efficiency was achieved with limited change in pH after calcium formate was added into the reactor, and it was found to work better than other additives tested. The positive effects were further verified in a power plant, which showed that adding calcium formate could promote the dissolution of calcium carbonate, accelerate the growth of gypsum crystals and improve the efficiency of desulfurization. Thus, calcium formate was proved to be an effective additive and can potentially be used to reduce the amount of limestone slurry required, as well as the energy consumption and operating costs in industrial desulfurization. Copyright © 2017. Published by Elsevier B.V.

Removal of Suspended Solids in Anaerobically Digested Slurries of Livestock and Poultry Manure by Coagulation Using Different Dosages of Polyaluminum Chloride

NASA Astrophysics Data System (ADS)

Li, P.; Zhang, C. J.; Zhao, T. K.; Zhong, H.

2017-01-01

In this study, anaerobically digested slurries of livestock and poultry manure were pretreated by coagulation-sedimentation using an inorganic polymer coagulant, polyaluminum chloride (PAC). The effect of different PAC dosages on suspended solids (SS) removal and pH in the biogas slurries was assessed to provide reference values for reducing the organic load of biogas slurry in the coagulation-sedimentation process and explore the feasibility of reducing the difficulty in subsequent utilization or processing of biogas slurry. The results showed that for the pig slurry containing approximately 5000 mg/L SS, the removal rate of SS reached up to 81.6% with the coagulant dosage of 0.28 g/L PAC. For the chicken slurry containing approximately 2600 mg/L SS, the removal rate of SS was 30.2% with the coagulant dosage of 0.33 g/L PAC. The removal rate of SS in both slurries of livestock and poultry manure exhibited a downward trend with high PAC dosage. Therefore, there is a need to control the PAC dosage in practical use. The pH changed little in the two types of biogas slurries after treatment with different PAC dosages and both were in line with the standard values specified in the “Standards for Irrigation Water Quality”.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yao, S.C.; Manwani, P.

Coal-water slurries have been regarded as a potential substitute for heavy fuel oil. Various demonstrations of coal-water slurry combustion have been performed; however, a fundamental understanding of how the combustion process of a slurry fuel is enhanced is still not adequate. The combustion of coal-water mixture droplets suspended on microthermocouples has been investigated. It was found that droplets of lignite coal (which is a noncaking coal) burn effectively; however, droplets of bituminous coal (which is a caking coal) are relatively difficult to burn. During the heat-up of bituminous coal-water slurry droplets may turn to ''popcorn'' and show significant agglomeration. Themore » incomplete combustion of coal-water slurry droplets in furnaces has been reported, and this is a drawback of this process. The objective of the present study is to explore the possibility of enhancing the combustion of coal-water slurry droplets with the use of a combustible emulsified oil.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sievers, David A.; Lischeske, James J.; Biddy, Mary J.

Solid-liquid separation of intermediate process slurries is required in some process configurations for the conversion of lignocellulosic biomass to transportation fuels. Thermochemically pretreated and enzymatically hydrolyzed corn stover slurries have proven difficult to filter due to formation of very low permeability cakes that are rich in lignin. Treatment of two different slurries with polyelectrolyte flocculant was demonstrated to increase mean particle size and filterability. Filtration flux was greatly improved, and thus scaled filter unit capacity was increased approximately 40-fold compared with unflocculated slurry. Although additional costs were accrued using polyelectrolyte, techno-economic analysis revealed that the increase in filter capacity significantlymore » reduced overall production costs. Fuel production cost at 95% sugar recovery was reduced by $1.35 US per gallon gasoline equivalent for dilute-acid pretreated and enzymatically hydrolyzed slurries and $3.40 for slurries produced using an additional alkaline de-acetylation preprocessing step that is even more difficult to natively filter.« less

Field Study on the formation and emission characteristics of PM2.5 in coal fired power plant unit

NASA Astrophysics Data System (ADS)

Xia, Yongjun; Huang, Guohui; Zhu, Yunpeng; Wang, Qian

2018-05-01

Particulate matter(PM) measurements were performed at the inlet and outlet of Fabric filter(FF) and the outlet of limestone-gypsum wet flue gas desulfurization (WFGD) tower at a 220MW pulverized coal fired power plant unit, and the PM formation characteristics, the performance characteristics of FF and the influence of WFGD to PM emission were discussed. The results showed that PM were of bimodal size distribution. The concentration of PMs larger than 2.5μm reduced in the WFGD while PMs less than 2.5μm particularly the PM diameter around 0.5μm increased due to the ultrafine PM aggregation as well as new PM formation from gypsum slurry entrainment.

Fired heater for coal liquefaction process

DOEpatents

Ying, David H. S.; McDermott, Wayne T.; Givens, Edwin N.

1985-01-01

A fired heater for a coal liquefaction process is operated under conditions to maximize the slurry slug frequency and thereby improve the heat transfer efficiency. The operating conditions controlled are (1) the pipe diameter and pipe arrangement, (2) the minimum coal/solvent slurry velocity, (3) the maximum gas superficial velocity, and (4) the range of the volumetric flow velocity ratio of gas to coal/solvent slurry.

An Approach to Understanding Cohesive Slurry Settling, Mobilization, and Hydrogen Gas Retention in Pulsed Jet Mixed Vessels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gauglitz, Phillip A.; Wells, Beric E.; Fort, James A.

2009-05-22

The Hanford Waste Treatment and Immobilization Plant (WTP) is being designed and built to pretreat and vitrify a large portion of the waste in Hanford’s 177 underground waste storage tanks. Numerous process vessels will hold waste at various stages in the WTP. Some of these vessels have mixing-system requirements to maintain conditions where the accumulation of hydrogen gas stays below acceptable limits, and the mixing within the vessels is sufficient to release hydrogen gas under normal conditions and during off-normal events. Some of the WTP process streams are slurries of solid particles suspended in Newtonian fluids that behave as non-Newtonianmore » slurries, such as Bingham yield-stress fluids. When these slurries are contained in the process vessels, the particles can settle and become progressively more concentrated toward the bottom of the vessels, depending on the effectiveness of the mixing system. One limiting behavior is a settled layer beneath a particle-free liquid layer. The settled layer, or any region with sufficiently high solids concentration, will exhibit non-Newtonian rheology where it is possible for the settled slurry to behave as a soft solid with a yield stress. In this report, these slurries are described as settling cohesive slurries.« less

An investigation on the rheological behavior of metallic semi-solid slurries of Al-6.5 pct Si and semi-solid composite slurries of SiC particulates in an Al-6.5 pct Si alloy matrix

NASA Technical Reports Server (NTRS)

Moon, H.-K.; Ito, Y.; Cornie, J. A.; Flemings, M. C.

1993-01-01

The rheology of SiC particulate/Al-6.5 pct Si composite slurries was explored. The rheological behavior of the composite slurries shows both thixotropic and pseudoplastic behaviors. Isostructural experiments on the composite slurries revealed a Newtonian behavior beyond a high shear rate limit. The rheology of fully molten composite slurries over the low to high shear rate range indicates the existence of a low shear rate Newtonian region, an intermediate pseudoplastic region and a high shear rate Newtonian region. The isostructural studies indicate that the viscosity of a composite slurry depends upon the shearing history of a given volume of material. An unexpected shear thinning was noted for SiC particulate + alpha slurries as compared to semi-solid metallic slurries at the same fraction solid. The implications of these findings for the processing of slurries into cast components is discussed.

Coal Liquefaction desulfurization process

DOEpatents

Givens, Edwin N.

1983-01-01

In a solvent refined coal liquefaction process, more effective desulfurization of the high boiling point components is effected by first stripping the solvent-coal reacted slurry of lower boiling point components, particularly including hydrogen sulfide and low molecular weight sulfur compounds, and then reacting the slurry with a solid sulfur getter material, such as iron. The sulfur getter compound, with reacted sulfur included, is then removed with other solids in the slurry.

Chemical-mechanical planarization of aluminum and copper interconnects with magnetic liners

NASA Astrophysics Data System (ADS)

Wang, Bin

2000-10-01

Chemical Mechanical Planarization (CMP) has been employed to achieve Damascene patterning of aluminum and copper interconnects with unique magnetic liners. A one-step process was developed for each interconnect scheme, using a double-layered pad with mesh cells, pores, and perforations on a top hard layer. In a hydrogen peroxide-based slurry, aluminum CMP was a process of periodic removal and formation of a surface oxide layer. Cu CMP in the same slurry, however, was found to be a dissolution dominant process. In a potassium iodate-based slurry, copper removal was the result of two competing reactions: copper dissolution and a non-native surface layer formation. Guided by electrochemistry, slurries were developed to remove nickel in different regimes of the corrosion kinetics diagram. Nickel CMP in a ferric sulfate-based slurry resulted in periodic removal and formation of a passive surface layer. In a potassium permanganate-based slurry, nickel removal is a dissolution dominant process. Visible Al(Cu) surface damages obtained with copper-doped aluminum could be eliminated by understanding the interactions between the substrate, the pad, and the abrasive agglomerate. Increasing substrate hardness by annealing prior to CMP led to a surface finish free of visible scratches. A similar result was also obtained by preventing formation of abrasive agglomerates and minimizing their contact with the substrate.

Improved coal-slurry pipeline

NASA Technical Reports Server (NTRS)

Dowler, W. L.

1979-01-01

High strength steel pipeline carries hot mixture of powdered coal and coal derived oil to electric-power-generating station. Slurry is processed along way to remove sulfur, ash, and nitrogen and to recycle part of oil. System eliminates hazards and limitations associated with anticipated coal/water-slurry pipelines.

Rheological properties of the product slurry of the Nitrate to Ammonia and Ceramic (NAC) process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muguercia, I.; Yang, G.; Ebadian, M.A.

The Nitrate to Ammonia and Ceramic (NAC) process is an innovative technology for immobilizing the liquid from Low Level radioactive Waste (LLW). An experimental study was conducted to measure the rheological properties of the pipe flow of the NAC product slurry. Test results indicate that the NAC product slurry has a profound rheological behavior. At low solids concentration, the slurry exhibits a typical dilatant fluid (or shear thinning)fluid. The transition from dilatant fluid to pseudo-plastic fluid will occur at between 25% to 30% solids concentration in temperature ranges of 50--80{degree}C. Correlation equations are developed based on the test data.

Replacing process water and nitrogen sources with biogas slurry during cellulosic ethanol production.

PubMed

You, Yang; Wu, Bo; Yang, Yi-Wei; Wang, Yan-Wei; Liu, Song; Zhu, Qi-Li; Qin, Han; Tan, Fu-Rong; Ruan, Zhi-Yong; Ma, Ke-Dong; Dai, Li-Chun; Zhang, Min; Hu, Guo-Quan; He, Ming-Xiong

2017-01-01

Environmental issues, such as the fossil energy crisis, have resulted in increased public attention to use bioethanol as an alternative renewable energy. For ethanol production, water and nutrient consumption has become increasingly important factors being considered by the bioethanol industry as reducing the consumption of these resources would decrease the overall cost of ethanol production. Biogas slurry contains not only large amounts of wastewater, but also the nutrients required for microbial growth, e.g., nitrogen, ammonia, phosphate, and potassium. Therefore, biogas slurry is an attractive potential resource for bioethanol production that could serve as an alternative to process water and nitrogen sources. In this study, we propose a method that replaces the process water and nitrogen sources needed for cellulosic ethanol production by Zymomonas mobilis with biogas slurry. To test the efficacy of these methods, corn straw degradation following pretreatment with diluted NaOH and enzymatic hydrolysis in the absence of fresh water was evaluated. Then, ethanol fermentation using the ethanologenic bacterial strain Z. mobilis ZMT2 was conducted without supplementing with additional nitrogen sources. After pretreatment with 1.34% NaOH (w/v) diluted in 100% biogas slurry and continuous enzymatic hydrolysis for 144 h, 29.19 g/L glucose and 12.76 g/L xylose were generated from 30 g dry corn straw. The maximum ethanol concentration acquired was 13.75 g/L, which was a yield of 72.63% ethanol from the hydrolysate medium. Nearly 94.87% of the ammonia nitrogen was depleted and no nitrate nitrogen remained after ethanol fermentation. The use of biogas slurry as an alternative to process water and nitrogen sources may decrease the cost of cellulosic ethanol production by 10.0-20.0%. By combining pretreatment with NaOH diluted in biogas slurry, enzymatic hydrolysis, and ethanol fermentation, 56.3 kg of ethanol was produced by Z. mobilis ZMT-2 through fermentation of 1000 kg of dried corn straw. In this study, biogas slurry replaced process water and nitrogen sources during cellulosic ethanol production. The results suggest that biogas slurry is a potential alternative to water when pretreating corn straw and, thus, has important potential applications in cellulosic ethanol production from corn straw. This study not only provides a novel method for utilizing biogas slurry, but also demonstrates a means of reducing the overall cost of cellulosic ethanol.

Supportability of a High-Yield-Stress Slurry in a New Stereolithography-Based Ceramic Fabrication Process

NASA Astrophysics Data System (ADS)

He, Li; Song, Xuan

2018-03-01

In recent years, ceramic fabrication using stereolithography (SLA) has gained in popularity because of its high accuracy and density that can be achieved in the final part of production. One of the key challenges in ceramic SLA is that support structures are required for building overhanging features, whereas removing these support structures without damaging the components is difficult. In this research, a suspension-enclosing projection-stereolithography process is developed to overcome this challenge. This process uses a high-yield-stress ceramic slurry as the feedstock material and exploits the elastic force of the material to support overhanging features without the need for building additional support structures. Ceramic slurries with different solid loadings are studied to identify the rheological properties most suitable for supporting overhanging features. An analytical model of a double doctor-blade module is established to obtain uniform and thin recoating layers from a high-yield-stress slurry. Several test cases highlight the feasibility of using a high-yield-stress slurry to support overhanging features in SLA.

High throughput screening of ligand binding to macromolecules using high resolution powder diffraction

DOEpatents

Von Dreele, Robert B.; D'Amico, Kevin

2006-10-31

A process is provided for the high throughput screening of binding of ligands to macromolecules using high resolution powder diffraction data including producing a first sample slurry of a selected polycrystalline macromolecule material and a solvent, producing a second sample slurry of a selected polycrystalline macromolecule material, one or more ligands and the solvent, obtaining a high resolution powder diffraction pattern on each of said first sample slurry and the second sample slurry, and, comparing the high resolution powder diffraction pattern of the first sample slurry and the high resolution powder diffraction pattern of the second sample slurry whereby a difference in the high resolution powder diffraction patterns of the first sample slurry and the second sample slurry provides a positive indication for the formation of a complex between the selected polycrystalline macromolecule material and at least one of the one or more ligands.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Underwood, R.P.

As part of the DOE-sponsored contract Synthesis of Dimethyl Ether and Alternative Fuels in the Liquid Phase from Coal-Derived Syngas'' experimental evaluations of the one-step synthesis of alternative fuels were carried out. The objective of this work was to develop novel processes for converting coal-derived syngas to fuels or fuel additives. Building on a technology base acquired during the development of the Liquid Phase Methanol (LPMEOH) process, this work focused on the development of slurry reactor based processes. The experimental investigations, which involved bench-scale reactor studies, focused primarily on three areas: (1) One-step, slurry-phase syngas conversion to hydrocarbons or methanol/hydrocarbonmore » mixtures using a mixture of methanol synthesis catalyst and methanol conversion catalyst in the same slurry reactor. (2) Slurry-phase conversion of syngas to mixed alcohols using various catalysts. (3) One-step, slurry-phase syngas conversion to mixed ethers using a mixture of mixed alcohols synthesis catalyst and dehydration catalyst in the same slurry reactor. The experimental results indicate that, of the three types of processes investigated, slurry phase conversion of syngas to mixed alcohols shows the most promise for further process development. Evaluations of various mixed alcohols catalysts show that a cesium-promoted Cu/ZnO/Al[sub 2]O[sub 3] methanol synthesis catalyst, developed in Air Products' laboratories, has the highest performance in terms of rate and selectivity for C[sub 2+]-alcohols. In fact, once-through conversion at industrially practical reaction conditions yielded a mixed alcohols product potentially suitable for direct gasoline blending. Moreover, an additional attractive aspect of this catalyst is its high selectivity for branched alcohols, potential precursors to iso-olefins for use in etherification.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Underwood, R.P.

As part of the DOE-sponsored contract ``Synthesis of Dimethyl Ether and Alternative Fuels in the Liquid Phase from Coal-Derived Syngas`` experimental evaluations of the one-step synthesis of alternative fuels were carried out. The objective of this work was to develop novel processes for converting coal-derived syngas to fuels or fuel additives. Building on a technology base acquired during the development of the Liquid Phase Methanol (LPMEOH) process, this work focused on the development of slurry reactor based processes. The experimental investigations, which involved bench-scale reactor studies, focused primarily on three areas: (1) One-step, slurry-phase syngas conversion to hydrocarbons or methanol/hydrocarbonmore » mixtures using a mixture of methanol synthesis catalyst and methanol conversion catalyst in the same slurry reactor. (2) Slurry-phase conversion of syngas to mixed alcohols using various catalysts. (3) One-step, slurry-phase syngas conversion to mixed ethers using a mixture of mixed alcohols synthesis catalyst and dehydration catalyst in the same slurry reactor. The experimental results indicate that, of the three types of processes investigated, slurry phase conversion of syngas to mixed alcohols shows the most promise for further process development. Evaluations of various mixed alcohols catalysts show that a cesium-promoted Cu/ZnO/Al{sub 2}O{sub 3} methanol synthesis catalyst, developed in Air Products` laboratories, has the highest performance in terms of rate and selectivity for C{sub 2+}-alcohols. In fact, once-through conversion at industrially practical reaction conditions yielded a mixed alcohols product potentially suitable for direct gasoline blending. Moreover, an additional attractive aspect of this catalyst is its high selectivity for branched alcohols, potential precursors to iso-olefins for use in etherification.« less

Process for electrochemically gasifying coal using electromagnetism

DOEpatents

Botts, Thomas E.; Powell, James R.

1987-01-01

A process for electrochemically gasifying coal by establishing a flowing stream of coal particulate slurry, electrolyte and electrode members through a transverse magnetic field that has sufficient strength to polarize the electrode members, thereby causing them to operate in combination with the electrolyte to electrochemically reduce the coal particulate in the slurry. Such electrochemical reduction of the coal produces hydrogen and carbon dioxide at opposite ends of the polarized electrode members. Gas collection means are operated in conjunction with the process to collect the evolved gases as they rise from the slurry and electrolyte solution.

Ceramic electrolyte coating and methods

DOEpatents

Seabaugh, Matthew M [Columbus, OH; Swartz, Scott L [Columbus, OH; Dawson, William J [Dublin, OH; McCormick, Buddy E [Dublin, OH

2007-08-28

Aqueous coating slurries useful in depositing a dense coating of a ceramic electrolyte material (e.g., yttrium-stabilized zirconia) onto a porous substrate of a ceramic electrode material (e.g., lanthanum strontium manganite or nickel/zirconia) and processes for preparing an aqueous suspension of a ceramic electrolyte material and an aqueous spray coating slurry including a ceramic electrolyte material. The invention also includes processes for depositing an aqueous spray coating slurry including a ceramic electrolyte material onto pre-sintered, partially sintered, and unsintered ceramic substrates and products made by this process.

Techno-economic assessment of the Mobil Two-Stage Slurry Fischer-Tropsch/ZSM-5 process

DOE Office of Scientific and Technical Information (OSTI.GOV)

El Sawy, A.; Gray, D.; Neuworth, M.

1984-11-01

A techno-economic assessment of the Mobil Two-Stage Slurry Fischer-Tropsch reactor system was carried out. Mobil bench-scale data were evaluated and scaled to a commercial plant design that produced specification high-octane gasoline and high-cetane diesel fuel. Comparisons were made with three reference plants - a SASOL (US) plant using dry ash Lurgi gasifiers and Synthol synthesis units, a modified SASOL plant with a British Gas Corporation slagging Lurgi gasifier (BGC/Synthol) and a BGC/slurry-phase process based on scaled data from the Koelbel Rheinpreussen-Koppers plant. A conceptual commercial version of the Mobil two-stage process shows a higher process efficiency than a SASOL (US)more » and a BGC/Synthol plant. The Mobil plant gave lower gasoline costs than obtained from the SASOL (US) and BGC/Synthol versions. Comparison with published data from a slurry-phase Fischer-Tropsch (Koelbel) unit indicated that product costs from the Mobil process were within 6% of the Koelbel values. A high-wax version of the Mobil process combined with wax hydrocracking could produce gasoline and diesel fuel at comparable cost to the lowest values achieved from prior published slurry-phase results. 27 references, 18 figures, 49 tables.« less

Process for changing caking coals to noncaking coals

DOEpatents

Beeson, Justin L.

1980-01-01

Caking coals are treated in a slurry including alkaline earth metal hydroxides at moderate pressures and temperatures in air to form noncaking carbonaceous material. Hydroxides such as calcium hydroxide, magnesium hydroxide or barium hydroxide are contemplated for slurrying with the coal to interact with the agglomerating constituents. The slurry is subsequently dewatered and dried in air at atmospheric pressure to produce a nonagglomerating carbonaceous material that can be conveniently handled in various coal conversion and combustion processes.

Semisolid Metal Processing Consortium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Apelian,Diran

Mathematical modeling and simulations of semisolid filling processes remains a critical issue in understanding and optimizing the process. Semisolid slurries are non-Newtonian materials that exhibit complex rheological behavior. There the way these slurries flow in cavities is very different from the way liquid in classical casting fills cavities. Actually filling in semisolid processing is often counter intuitive

Final Report - "Foaming and Antifoaming and Gas Entrainment in Radioactive Waste Pretreatment and Immobilization Processes"

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wasan, Darsh T.

2007-10-09

The Savannah River Site (SRS) and Hanford site are in the process of stabilizing millions of gallons of radioactive waste slurries remaining from production of nuclear materials for the Department of Energy (DOE). The Defense Waste Processing Facility (DWPF) at SRS is currently vitrifying the waste in borosilicate glass, while the facilities at the Hanford site are in the construction phase. Both processes utilize slurry-fed joule-heated melters to vitrify the waste slurries. The DWPF has experienced difficulty during operations. The cause of the operational problems has been attributed to foaming, gas entrainment and the rheological properties of the process slurries.more » The rheological properties of the waste slurries limit the total solids content that can be processed by the remote equipment during the pretreatment and meter feed processes. Highly viscous material can lead to air entrainment during agitation and difficulties with pump operations. Excessive foaming in waste evaporators can cause carryover of radionuclides and non-radioactive waste to the condensate system. Experimental and theoretical investigations of the surface phenomena, suspension rheology and bubble generation of interactions that lead to foaming and air entrainment problems in the DOE High Level and Low Activity Radioactive Waste separation and immobilization processes were pursued under this project. The first major task accomplished in the grant proposal involved development of a theoretical model of the phenomenon of foaming in a three-phase gas-liquid-solid slurry system. This work was presented in a recently completed Ph.D. thesis (9). The second major task involved the investigation of the inter-particle interaction and microstructure formation in a model slurry by the batch sedimentation method. Both experiments and modeling studies were carried out. The results were presented in a recently completed Ph.D. thesis. The third task involved the use of laser confocal microscopy to study the effectiveness of three slurry rheology modifiers. An effective modifier was identified which resulted in lowering the yield stress of the waste simulant. Therefore, the results of this research have led to the basic understanding of the foaming/antifoaming mechanism in waste slurries as well as identification of a rheology modifier, which enhances the processing throughput, and accelerates the DOE mission. The objectives of this research effort were to develop a fundamental understanding of the physico-chemical mechanisms that produced foaming and air entrainment in the DOE High Level (HLW) and Low Activity (LAW) radioactive waste separation and immobilization processes, and to develop and test advanced antifoam/defoaming/rheology modifier agents. Antifoams/rheology modifiers developed from this research ere tested using non-radioactive simulants of the radioactive wastes obtained from Hanford and the Savannah River Site (SRS).« less

Process for electrochemically gasifying coal

DOEpatents

Botts, T.E.; Powell, J.R.

1985-10-25

A process is claimed for electrochemically gasifying coal by establishing a flowing stream of coal particulate slurry, electrolyte and electrode members through a transverse magnetic field that has sufficient strength to polarize the electrode members, thereby causing them to operate in combination with the electrolyte to electrochemically reduce the coal particulate in the slurry. Such electrochemical reduction of the coal produces hydrogen and carbon dioxide at opposite ends of the polarized electrode members. Gas collection means are operated in conjunction with the process to collect the evolved gases as they rise from the slurry and electrolyte solution. 7 figs.

Kinetics of autotrophic denitrification process and the impact of sulphur/limestone ratio on the process performance.

PubMed

Kilic, Arzu; Sahinkaya, Erkan; Cinar, Ozer

2014-01-01

Kinetics of sulphur-limestone autotrophic denitrification process in batch assays and the impact of sulphur/limestone ratio on the process performance in long-term operated packed-bed bioreactors were evaluated. The specific nitrate and nitrite reduction rates increased almost linearly with the increasing initial nitrate and nitrite concentrations, respectively. The process performance was evaluated in three parallel packed-bed bioreactors filled with different sulphur/limestone ratios (1:1, 2:1 and 3:1, v/v). Performances of the bioreactors were studied under varying nitrate loadings (0.05 - 0.80 gNO(-)(3) - NL⁻¹ d⁻¹) and hydraulic retention times (3-12 h). The maximum nitrate reduction rate of 0.66 g L⁻¹ d⁻¹ was observed at the loading rate of 0.80 g NO(-)(3) - N L⁻¹ d⁻¹ in the reactor with sulphur/limestone ratio of 3:1. Throughout the study, nitrite concentrations remained quite low (i.e. below 0.5 mg L⁻¹ NO(-)(2) -N. The reactor performance increased in the order of sulphur/limestone ratio of 3:1, 2:1 and 1:1. Denaturing gradient gel electrophoresis analysis of 16S rRNA genes showed quite stable communities in the reactors with the presence of Methylo virgulaligni, Sulfurimonas autotrophica, Sulfurovum lithotrophicum, Thiobacillus aquaesulis and Sulfurimonas autotrophica related species.

Dynamic NMR Study of Model CMP Slurry Containing Silica Particles as Abrasives

NASA Astrophysics Data System (ADS)

Odeh, F.; Al-Bawab, A.; Li, Y.

2018-02-01

Chemical mechanical planarization (CMP) should provide a good surface planarity with minimal surface defectivity. Since CMP slurries are multi-component systems, it is very important to understand the various processes and interactions taking place in such slurries. Several techniques have been employed for such task, however, most of them lack the molecular recognition to investigate molecular interactions without adding probes which in turn increase complexity and might alter the microenvironment of the slurry. Nuclear magnetic resonance (NMR) is a powerful technique that can be employed in such study. The longitudinal relaxation times (T1) of the different components of CMP slurries were measured using Spin Echo-NMR (SE-NMR) at a constant temperature. The fact that NMR is non-invasive and gives information on the molecular level gives more advantage to the technique. The model CMP slurry was prepared in D2O to enable monitoring of T1 for the various components' protons. SE-NMR provide a very powerful tool to study the various interactions and adsorption processes that take place in a model CMP silica based slurry which contains BTA and/or glycine and/or Cu+2 ions. It was found that BTA is very competitive towards complexation with Cu+2 ions and BTA-Cu complex adsorbs on silica surface.

Theoretical Combustion Performance of Several High-Energy Fuels for Ramjet Engines

NASA Technical Reports Server (NTRS)

Tower, Leonard K; Breitwieser, Roland; Gammon, Benson E

1958-01-01

An analytical evaluation of the air and fuel specific-impulse characteristics of magnesium, magnesium octene-1 slurries, aluminum, aluminum octene-1 slurries, boron, boron octene-1 slurries, carbon, hydrogen, alpha-methylnaphthalene, diborane, pentaborane, and octene-1 is presented. While chemical equilibrium was assumed in the combustion process, the expansion was assumed to occur at fixed composition.

Ceramic electrolyte coating methods

DOEpatents

Seabaugh, Matthew M.; Swartz, Scott L.; Dawson, William J.; McCormick, Buddy E.

2004-10-12

Processes for preparing aqueous suspensions of a nanoscale ceramic electrolyte material such as yttrium-stabilized zirconia. The invention also includes a process for preparing an aqueous coating slurry of a nanoscale ceramic electrolyte material. The invention further includes a process for depositing an aqueous spray coating slurry including a ceramic electrolyte material on pre-sintered, partially sintered, and unsintered ceramic substrates and products made by this process.

Effect of fabrication parameters on coating properties of tubular solid oxide fuel cell electrolyte prepared by vacuum slurry coating

NASA Astrophysics Data System (ADS)

Son, Hui-Jeong; Song, Rak-Hyun; Lim, Tak-Hyoung; Lee, Seung-Bok; Kim, Sung-Hyun; Shin, Dong-Ryul

The process of vacuum slurry coating for the fabrication of a dense and thin electrolyte film on a porous anode tube is investigated for application in solid oxide fuel cells. 8 mol% yttria stabilized zirconia is coated on an anode tube by vacuum slurry-coating process as a function of pre-sintering temperature of the anode tube, vacuum pressure, slurry concentration, number of coats, and immersion time. A dense electrolyte layer is formed on the anode tube after final sintering at 1400 °C. With decrease in the pre-sintering temperature of the anode tube, the grain size of the coated electrolyte layer increases and the number of surface pores in the coating layer decreases. This is attributed to a reduced difference in the respective shrinkage of the anode tube and the electrolyte layer. The thickness of the coated electrolyte layer increases with the content of solid powder in the slurry, the number of dip-coats, and the immersion time. Although vacuum pressure has no great influence on the electrolyte thickness, higher vacuum produces a denser coating layer, as confirmed by low gas permeability and a reduced number of defects in the coating layer. A single cell with the vacuum slurry coated electrolyte shows a good performance of 620 mW cm -2 (0.7 V) at 750 °C. These experimental results indicate that the vacuum slurry-coating process is an effective method to fabricate a dense thin film on a porous anode support.

A novel approach of chemical mechanical polishing using environment-friendly slurry for mercury cadmium telluride semiconductors

PubMed Central

Zhang, Zhenyu; Wang, Bo; Zhou, Ping; Guo, Dongming; Kang, Renke; Zhang, Bi

2016-01-01

A novel approach of chemical mechanical polishing (CMP) is developed for mercury cadmium telluride (HgCdTe or MCT) semiconductors. Firstly, fixed-abrasive lapping is used to machine the MCT wafers, and the lapping solution is deionized water. Secondly, the MCT wafers are polished using the developed CMP slurry. The CMP slurry consists of mainly SiO2 nanospheres, H2O2, and malic and citric acids, which are different from previous CMP slurries, in which corrosive and toxic chemical reagents are usually employed. Finally, the polished MCT wafers are cleaned and dried by deionized water and compressed air, respectively. The novel approach of CMP is environment-friendly. Surface roughness Ra, and peak-to-valley (PV) values of 0.45, and 4.74 nm are achieved, respectively on MCT wafers after CMP. The first and second passivating processes are observed in electrochemical measurements on MCT wafers. The fundamental mechanisms of CMP are proposed according to the X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. Malic and citric acids dominate the first passivating process, and the CMP slurry governs the second process. Te4+3d peaks are absent after CMP induced by the developed CMP slurry, indicating the removing of oxidized films on MCT wafers, which is difficult to achieve using single H2O2 and malic and citric acids solutions. PMID:26926622

Diagenetic patterns and pore space distribution along a platform to outer-shelf transect (Urgonian limestone, Barremian-Aptian, SE France)

NASA Astrophysics Data System (ADS)

Léonide, Philippe; Fournier, François; Reijmer, John J. G.; Vonhof, Hubert; Borgomano, Jean; Dijk, Jurrien; Rosenthal, Maelle; van Goethem, Manon; Cochard, Jean; Meulenaars, Karlien

2014-06-01

The Urgonian limestones of Late Barremian/Early Aptian from Provence (SE, France) are characterized by the occurrence of microporous limestones at regional scale alternating with tight carbonates. This study, based on petrographical (sediment texture, facies) and diagenetical analyses (cement stratigraphy, porosity and isotope geochemistry) of more than 800 limestone samples provides insight into the parameters controlling the genesis, preservation or occlusion of microporosity along an inner platform to outer shelf transect. The tight and microporous Urgonian limestones from Provence can be grouped into 5 rock-types based on textures, associated depositional environments, porosity and pore-type, being: (1) tight inner-platform: TIP; (2) porous inner platform: PIP; (3) tight outer platform: TOP; (4) porous outer platform: POP and (5) tight outer shelf: TOS. In tight (TIP, TOP and TOS types) limestones intergranular and intragranular pore spaces were entirely occluded by early marine and/or early meteoric cementation, whereas in microporous (PIP, POP) limestones a significant fraction of the intergranular macroporosity was preserved during early and shallow burial diagenesis. Micrite neomorphism (hybrid Ostwald ripening process) occurred during meteoric shallow burial diagenesis in PIP and POP limestones during the regional Durancian Uplift event (Albian-Lower Cenomanian). This process resulted in microporosity enhancement and preservation. Circulation of meteoric fluids during exhumation produces intercrystalline microporosity enhancement and moldic porosity development. The present study documents the important role that both early diagenetic and depositional cycles and long-term tectonic processes have on pore space evolution and distribution in Mesozoic platform carbonates.

Combustion characterization of carbonized RDF, Joint Venture Task No. 7. Topical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

1995-04-30

The overall objective of this research program was to demonstrate EnerTech's and the Energy & Environmental Research Center's (EERC) process of slurry carbonization for producing homogeneous, pumpable titels from refuse-derived fuel (RDF) with continuous pilot plant facilities, and to characterize flue gas and ash emissions from combustion of the carbonizd RDF slurry fuel. Please note that "Wet Thermal Oxidation" is EnerTech's trademark mme for combustion of the carbonized RDF slurry fuel. Carbonized RDF slurry fuels were produced with the EERC'S 7.5-tpd (wet basis) pilot plant facility. A hose diaphragm pump pressurized a 7- lo-wt% feed RDF slurry, with a viscositymore » of 500 cP, to approximately 2500 psig. The pressurized RDF slurry was heated by indirect heat exchangers to between 5850 -626°F, and its temperature and pressure was maintained in a downflow reactor. The carbonized slurry was flashed, concentrated in a filter press, and ground in an attritor. During operation of the pilot plant, samples of the feed RDF slurry, carbonization gas, condensate, carbonized solids, and filtrate were taken and analyzed. Pilot-scale slurry carbonization experiments with RDF produced a homogeneous pumpable slurry fuel with a higher heating value (HHV) of 3,000-6,600 Btu/lb (as-received basis), at a viscosity of 500 CP at 100 Hz decreasing, and ambient temperature. Greater-heating-value slurry fuels were produced at higher slurry carbonization temperatures. During slurry carbonization, polyvinyl chloride (PVC) plastics in the feed RDF also decompose to form hydrochloric acid and salts. Pilot-scale slurty carbonization experiments extracted 82-94% of the feed RDF chlorine content as chloride salts. Higher carbonization temperatures and higher alkali additions to the feed slurry produced a higher chlorine extraction.« less

Removal of enzymatic and fermentation inhibitory compounds from biomass slurries for enhanced biorefinery process efficiencies.

PubMed

Gurram, Raghu N; Datta, Saurav; Lin, Yupo J; Snyder, Seth W; Menkhaus, Todd J

2011-09-01

Within the biorefinery paradigm, many non-monomeric sugar compounds have been shown to be inhibitory to enzymes and microbial organisms that are used for hydrolysis and fermentation. Here, two novel separation technologies, polyelectrolyte polymer adsorption and resin-wafer electrodeionization (RW-EDI), have been evaluated to detoxify a dilute acid pretreated biomass slurry. Results showed that detoxification of a dilute acid pretreated ponderosa pine slurry by sequential polyelectrolyte and RW-EDI treatments was very promising, with significant removal of acetic acid, 5-hydroxymethyl furfural, and furfural (up to 77%, 60%, and 74% removed, respectively) along with >97% removal of sulfuric acid. Removal of these compounds increased the cellulose conversion to 94% and elevated the hydrolysis rate to 0.69 g glucose/L/h. When using Saccharomyces cerevisiae D(5)A for fermentation of detoxified slurry, the process achieved 99% of the maximum theoretical ethanol yield and an ethanol production rate nearly five-times faster than untreated slurry. Copyright © 2011 Elsevier Ltd. All rights reserved.

Solvent-Free Manufacturing of Electrodes for Lithium-ion Batteries

NASA Astrophysics Data System (ADS)

Ludwig, Brandon; Zheng, Zhangfeng; Shou, Wan; Wang, Yan; Pan, Heng

2016-03-01

Lithium ion battery electrodes were manufactured using a new, completely dry powder painting process. The solvents used for conventional slurry-cast electrodes have been completely removed. Thermal activation time has been greatly reduced due to the time and resource demanding solvent evaporation process needed with slurry-cast electrode manufacturing being replaced by a hot rolling process. It has been found that thermal activation time to induce mechanical bonding of the thermoplastic polymer to the remaining active electrode particles is only a few seconds. Removing the solvent and drying process allows large-scale Li-ion battery production to be more economically viable in markets such as automotive energy storage systems. By understanding the surface energies of various powders which govern the powder mixing and binder distribution, bonding tests of the dry-deposited particles onto the current collector show that the bonding strength is greater than slurry-cast electrodes, 148.8 kPa as compared to 84.3 kPa. Electrochemical tests show that the new electrodes outperform conventional slurry processed electrodes, which is due to different binder distribution.

Experimental Study of Heat Transfer Performance of Polysilicon Slurry Drying Process

NASA Astrophysics Data System (ADS)

Wang, Xiaojing; Ma, Dongyun; Liu, Yaqian; Wang, Zhimin; Yan, Yangyang; Li, Yuankui

2016-12-01

In recent years, the growth of the solar energy photovoltaic industry has greatly promoted the development of polysilicon. However, there has been little research into the slurry by-products of polysilicon production. In this paper the thermal performance of polysilicon slurry was studied in an industrial drying process with a twin-screw horizontal intermittent dryer. By dividing the drying process into several subunits, the parameters of each unit could be regarded as constant in that period. The time-dependent changes in parameters including temperature, specific heat and evaporation enthalpy were plotted. An equation for the change in the heat transfer coefficient over time was calculated based on heat transfer equations. The concept of a distribution coefficient was introduced to reflect the influence of stirring on the heat transfer area. The distribution coefficient ranged from 1.2 to 1.7 and was obtained with the fluid simulation software FLUENT, which simplified the calculation of heat transfer area during the drying process. These experimental data can be used to guide the study of polysilicon slurry drying and optimize the design of dryers for industrial processes.

Thermophilic aeration of cattle slurry with whey and/or jam wastes.

PubMed

Heinonen-Tanski, Helvi; Kiuru, Tapio; Ruuskanen, Juhani; Korhonen, Kari; Koivunen, Jari; Ruokojärvi, Arja

2005-01-01

Thermophilic aeration of cattle slurry and food industrial by-products was studied with the aim to improve hygienic qualities of the slurry so that it could be used as a safe fertiliser for berries to be eaten raw. We also wanted to study if the process would be energetically favourable in an arctic climate. Cattle slurry alone or with whey and/or jam waste was treated. The tests were done in a well heat-insulated reactor with a 10 m(3) volume. Temperature increases up to over 70 degrees C could be recorded in 19 days even though some processes were carried out in winter time when the ambient air temperature was less than 0 degrees C. The heat energy formed was higher than the electrical energy needed to carry out the aeration. The hygienic qualities of the aerated product were good with only minor nitrogen losses. The end product could be useful as a fertiliser and soil improving compound to increase the organic matter content of agricultural soil. Cattle slurry alone was well suited as the raw material if attaining a high temperature was the main goal. A part of slurry could be replaced with food-industrial side products. Whey waste suited better for co-composting than jam waste but the mixture of whey, jam waste, and slurry was optimal for composting.

Rested and stressed farmed Atlantic cod (Gadus morhua) chilled in ice or slurry and effects on quality.

PubMed

Digre, Hanne; Erikson, Ulf; Aursand, Ida G; Gallart-Jornet, Lorena; Misimi, Ekrem; Rustad, Turid

2011-01-01

The main objectives of this study were to investigate (1) whether rested harvest of farmed cod was better maintained by chilling with slurry rather than by traditional ice storage, (2) whether chilling with slurry would be a feasible chilling method to assure low core temperatures (≤0 °C) at packing of gutted fish, and (3) the effects of superchilling compared with traditional ice on selected quality parameters of cod during storage. In the experiment, seawater slurry at -2.0 ± 0.3 °C was used. Anesthetized (AQUI-S™), percussion stunned, and stressed cod chilled in slurry were compared. Cod stored on ice were used as reference group. The fish were evaluated at the day of slaughter, and after 7 and 14 d of storage according to handling stress (initial muscle pH, muscle twitches, rigor mortis), core temperatures, quality index method, microbial counts, weight changes, salt and water content, water distribution, pH, adenosine triphosphate-degradation products, K-value, water-holding capacity, fillet color, and texture. Chilling cod in slurry was more rapid than chilling in ice. Prechilling (1 d) of cod in slurry before subsequent ice storage resulted in lower quality 7 d postmortem compared with both ice and continuous slurry storage. The potential advantages of superchilling became more prominent after 14 d with lower microbiological activity, better maintenance of freshness (lower total quality index scores and lower K-values) compared with fish stored on ice. A drawback with slurry-stored fish was that cloudy eyes developed earlier, in addition to weight gain and salt uptake compared to ice-stored fish. Practical Application: Chilling is an essential operation in any fish-processing plant. This manuscript addresses different applications of slurry ice in the processing and storage of Atlantic cod. Cod quality was assessed after 7 and 14 d of iced and superchilled storage.

Processable Aromatic Polyimide Thermoplastic Blends

NASA Technical Reports Server (NTRS)

Baucom, Robert M; Johnston, Norman J.; St. Clair, Terry L.; Nelson, James B.; Gleason, John R.; Proctor, K. Mason

1988-01-01

Method developed for preparing readily-processable thermoplastic polyimides by blending linear, high-molecular-weight, polyimic acid solutions in ether solvents with ultrafine, semicrystalline, thermoplastic polyimide powders. Slurries formed used to make prepregs. Consolidation of prepregs into finsihed composites characterized by excellent melt flow during processing. Applied to film, fiber, fabric, metal, polymer, or composite surfaces. Used to make various stable slurries from which prepregs prepared.

Combined slurry and cavitation erosion resistance of surface modified SS410 stainless steel

NASA Astrophysics Data System (ADS)

Amarendra, H. J.; Pratap, M. S.; Karthik, S.; Punitha Kumara, M. S.; Rajath, H. C.; Ranjith, H.; Shubhatunga, S. V.

2018-03-01

Slurry erosion and combined slurry and cavitation erosion resistance of thermal spray coatings are studied and compared with the as-received martensitic stainless steel material. 70Ni-Cr coatings are deposited on SS 410 material through plasma thermal spray process. The synergy effect of the combined slurry and cavitation erosion resistance of plasma thermal spray coatings were investigated in a slurry pot tester in the presence of bluff bodies known as Cavitation Inducers. Results showed the combined slurry and cavitation erosion resistance of martensitic stainless steel - 410 can be improved by plasma thermal spray coating. It is observed that the plasma spray coated specimens are better erosion resistant than the as- received material, subjected to erosion test under similar conditions. As-received and the surface modified steels are mechanically characterized for its hardness, bending. Morphological studies are conducted through scanning electron microscope.

OPTIMIZATION OF A PULSED LIMESTONE BED REACTOR AT THE ARGO TUNNEL IN IDAHO SPRINGS, COLORADO

EPA Science Inventory

Acid Mine Drainage (AMD) is an unintended consequence of coal and metal mining that adversely affects thousands of miles of streams both in the eastern and western regions of the U.S. A novel AMD treatment process based on limestone based on limestone neutralization has been dev...

Technical Development of Slurry Three-Dimensional Printer

NASA Astrophysics Data System (ADS)

Jiang, Cho-Pei; Hsu, Huang-Jan; Lee, Shyh-Yuan

2017-09-01

The aim of this paper is to review the technical development of slurry three-dimensional printer (3DP) which based on photo-polymerization and constrained surface method. Basically, slurry consists of ceramic powder, resin and photo-initiator. The light engines for solidifying the photo-curable slurry can be classified as laser, liquid crystal panel (LCD), digital light processing (DLP). The slurry can be reacted and solidified by selective ray according to the reaction spectrum of photo-initiator. Ceramic powder used in this study is zirconia oxide. Experimental results show that ceramic particle size affects the viscosity of slurry severely resulting in low accuracy and the occurrence of micro crack in the layer casting procedure. Therefore, the effect of particle size on the curability and accuracy of built green part is discussed. A single dental crown is proposed to be fabricated by these three light engines as a benchmark for comparison. In addition, the cost and the limitation are compared in the aspect of dental crown fabrication. Consequently, the lowest cost is LCD-type slurry 3DP system. DLP-type slurry 3DP can produce green body with the fastest fabrication time. The volumetric error of sintered part that made by these three fabrication methods is similar because the composition of slurry is the same.

Pilot-scale Limestone Emission Control (LEC) process: A development project. Volume 1, Main report and appendices A, B, C, and D: Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prudich, M.E.; Appell, K.W.; McKenna, J.D.

ETS, Inc., a pollution consulting firm with headquarters in Roanoke, Virginia, has developed a dry, limestone-based flue gas desulfurization (FGD) system. This SO{sub 2} removal system, called Limestone Emission Control (LEC), can be designed for installation on either new or existing coal-fired boilers. In the LEC process, the SO{sub 2} in the flue gas reacts with wetted granular limestone that is contained in a moving bed. A surface layer of principally calcium sulfate (CaSO{sub 4}) is formed on the limestone. Periodic removal of this surface layer by mechanical agitation allows high utilization of the limestone granules. A nominal 5,000 acfmmore » LEC pilot plant has been designed, fabricated and installed on the slipstream of a 70,000 pph stoker boiler providing steam to Ohio University`s Athens, Ohio campus. A total of over 90 experimental trials have been performed using the pilot-scale moving-bed LEC dry scrubber as a part of this research project with run times ranging up to a high of 125 hours. SO{sub 2} removal efficiencies as high as 99.9% were achievable for all experimental conditions studied during which sufficient humidification was added to the LEC bed. The LEC process and conventional limestone scrubbing have been compared on an equatable basis using flue gas conditions that would be expected at the outlet of the electrostatic precipitator (ESP) of a 500 MW coal-fired power plant. The LEC was found to have a definite economic advantage in both direct capital costs and operating costs. Based on the success and findings of the present project, the next step in LEC process development will be a full-scale commercial demonstration unit.« less

Coal liquefaction process

DOEpatents

Carr, Norman L.; Moon, William G.; Prudich, Michael E.

1983-01-01

A C.sub.5 -900.degree. F. (C.sub.5 -482.degree. C.) liquid yield greater than 50 weight percent MAF feed coal is obtained in a coal liquefaction process wherein a selected combination of higher hydrogen partial pressure, longer slurry residence time and increased recycle ash content of the feed slurry are controlled within defined ranges.

Preparing polymeric matrix composites using an aqueous slurry technique

NASA Technical Reports Server (NTRS)

Johnston, Norman J. (Inventor); Towell, Timothy W. (Inventor)

1993-01-01

An aqueous process was developed to prepare a consolidated composite laminate from an aqueous slurry. An aqueous poly(amic acid) surfactant solution was prepared by dissolving a poly(amic acid) powder in an aqueous ammonia solution. A polymeric powder was added to this solution to form a slurry. The slurry was deposited on carbon fiber to form a prepreg which was dried and stacked to form a composite laminate. The composite laminate was consolidated using pressure and was heated to form the polymeric matrix. The resulting composite laminate exhibited high fracture toughness and excellent consolidation.

Method of producing a colloidal fuel from coal and a heavy petroleum fraction. [partial liquefaction of coal in slurry, filtration and gasification of residue

DOEpatents

Longanbach, J.R.

1981-11-13

A method is provided for combining coal as a colloidal suspension within a heavy petroleum fraction. The coal is broken to a medium particle size and is formed into a slurry with a heavy petroleum fraction such as a decanted oil having a boiling point of about 300 to 550/sup 0/C. The slurry is heated to a temperature of 400 to 500/sup 0/C for a limited time of only about 1 to 5 minutes before cooling to a temperature of less than 300/sup 0/C. During this limited contact time at elevated temperature the slurry can be contacted with hydrogen gas to promote conversion. The liquid phase containing dispersed coal solids is filtered from the residual solids and recovered for use as a fuel or feed stock for other processes. The residual solids containing some carbonaceous material are further processed to provide hydrogen gas and heat for use as required in this process.

Ignition and combustion characteristics of metallized propellants

NASA Technical Reports Server (NTRS)

Mueller, D. C.; Turns, Stephen R.

1991-01-01

Over the past six months, experimental investigations were continued and theoretical work on the secondary atomization process was begun. Final shakedown of the sizing/velocity measuring system was completed and the aluminum combustion detection system was modified and tested. Atomizer operation was improved to allow steady state operation over long periods of time for several slurries. To validate the theoretical modeling, work involving carbon slurry atomization and combustion was begun and qualitative observations were made. Simultaneous measurements of aluminum slurry droplet size distributions and detection of burning aluminum particles were performed at several axial locations above the burner. The principle theoretical effort was the application of a rigid shell formation model to aluminum slurries and an investigation of the effects of various parameters on the shell formation process. This shell formation model was extended to include the process leading up to droplet disruption, and previously developed analytical models were applied to yield theoretical aluminum agglomerate ignition and combustion times. The several theoretical times were compared with the experimental results.

Characterization of the SRNL-Washed tank 51 sludge batch 9 qualification sample

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pareizs, J. M.

2016-01-01

Savannah River National Laboratory (SRNL) personnel have been requested to qualify the next sludge batch (Sludge Batch 9 – SB9) for processing at the Defense Waste Processing Facility (DWPF). To accomplish this task, Savannah River Remediation (SRR) sent SRNL a 3-L sample of Tank 51H slurry to be characterized, washed, and then used in a lab-scale demonstration of the DWPF flowsheet (after combining with Tank 40H sludge). SRNL has washed the Tank 51H sample per the Tank Farm washing strategy as of October 20, 2015. A part of the qualification process is extensive radionuclide and chemical characterization of the SRNL-washedmore » Tank 51H slurry. This report documents the chemical characterization of the washed slurry; radiological characterization is in progress and will be documented in a separate report. The analytical results of this characterization are comparable to the Tank Farm projections. Therefore, it is recommended that SRNL use this washed slurry for the ongoing SB9 qualification activities.« less

Sludge batch 9 (SB9) acceptance evaluation. Radionuclide concentrations in tank 51 SB9 qualification sample prepared at SRNL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bannochie, C. J.; Diprete, D. P.; Pareizs, J. M.

Presented in this report are radionuclide concentrations required as part of the program of qualifying Sludge Batch 9 (SB9) for processing in the Defense Waste Processing Facility (DWPF). The SB9 material is currently in Tank 51 and has been washed and prepared for transfer to Tank 40. The acceptance evaluation needs to be completed prior to the transfer of the material in Tank 51 to Tank 40. The sludge slurry in Tank 40 has already been qualified for DWPF processing and is currently being processed as Sludge Batch 8 (SB8). The radionuclide concentrations were measured or estimated in the Tankmore » 51 SB9 Washed Qualification Sample prepared at Savannah River National Laboratory (SRNL). This sample was prepared from a three liter sample of Tank 51 sludge slurry (HTF-51-15-81) taken on July 23, 2015. The sample was delivered to SRNL where it was initially characterized in the Shielded Cells. Under the direction of Savannah River Remediation (SRR) it was then adjusted per the Tank Farm washing strategy as of October 20, 2015. This final slurry now has a composition expected to be similar to that of the slurry in Tank 51 after final preparations have been made for transfer of that slurry to Tank 40.« less

Sludge batch 9 (SB9) accepance evaluation: Radionuclide concentrations in tank 51 SB9 qualification sample prepared at SRNL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bannochie, C.; Diprete, D.; Pareizs, J.

Presented in this report are radionuclide concentrations required as part of the program of qualifying Sludge Batch 9 (SB9) for processing in the Defense Waste Processing Facility (DWPF). The SB9 material is currently in Tank 51 and has been washed and prepared for transfer to Tank 40. The acceptance evaluation needs to be completed prior to the transfer of the material in Tank 51 to Tank 40. The sludge slurry in Tank 40 has already been qualified for DWPF processing and is currently being processed as Sludge Batch 8 (SB8). The radionuclide concentrations were measured or estimated in the Tankmore » 51 SB9 Washed Qualification Sample prepared at Savannah River National Laboratory (SRNL). This sample was prepared from a three liter sample of Tank 51 sludge slurry (HTF-51-15-81) taken on July 23, 2015. The sample was delivered to SRNL where it was initially characterized in the Shielded Cells. Under the direction of Savannah River Remediation (SRR) it was then adjusted per the Tank Farm washing strategy as of October 20, 2015. This final slurry now has a compositioniv expected to be similar to that of the slurry in Tank 51 after final preparations have been made for transfer of that slurry to Tank 40.« less

Accelerated weathering of limestone for CO2 mitigation: Opportunities for the stone and cement industries

USGS Publications Warehouse

Langer, William H.; San, Juan A.; Rau, Greg H.; Caldeira, Ken

2009-01-01

Large amounts of limestone fines co-produced during the processing of crushed limestone may be useful in the sequestration of carbon dioxide (CO2). Accelerated weathering of limestone (AWL) is proposed as a low-tech method to capture and sequester CO2 from fossil fuel-fired power plants and other point sources such as cement manufacturing. AWL reactants are readily available, inexpensive and environmentally benign. Waste CO2 is hydrated with water to produce carbonic acid. This reacts with and is neutralized by limestone fines, thus converting CO2 gas to dissolved calcium bicarbonate.

IMPROVED MAGNESIUM OXIDE SLIP CASTING METHOD

DOEpatents

Stoddard, S.D.; Nuckolls, D.E.

1963-12-31

A process for making an aqueous magnesium oxide slip casting slurry comprising the steps of mixing finely ground fused magnesium oxide with water, milling the slurry for at least 30 hours at a temperature of 2-10 deg C (the low temperature during milling inhibiting the formation of hydrated magnesium oxide), discharging the slurry from the mill, adding hydrochloric acid as a deflocculent, and adding a scum inhibitor is presented. (AEC)

Process for removing sulfur from sulfur-containing gases: high calcium fly-ash

DOEpatents

Rochelle, Gary T.; Chang, John C. S.

1991-01-01

The present disclosure relates to improved processes for treating hot sulfur-containing flue gas to remove sulfur therefrom. Processes in accordance with the present invention include preparing an aqueous slurry composed of a calcium alkali source and a source of reactive silica and/or alumina, heating the slurry to above-ambient temperatures for a period of time in order to facilitate the formation of sulfur-absorbing calcium silicates or aluminates, and treating the gas with the heat-treated slurry components. Examples disclosed herein demonstrate the utility of these processes in achieving improved sulfur-absorbing capabilities. Additionally, disclosure is provided which illustrates preferred configurations for employing the present processes both as a dry sorbent injection and for use in conjunction with a spray dryer and/or bagfilter. Retrofit application to existing systems is also addressed.

Emissions of ammonia, carbon dioxide, and hydrogen sulfide from swine wastewater during and after acidification treatment: effect of pH, mixing and aeration.

PubMed

Dai, X R; Blanes-Vidal, V

2013-01-30

This study aimed at evaluating the effect of swine slurry acidification and acidification-aeration treatments on ammonia (NH(3)), carbon dioxide (CO(2)) and hydrogen sulfide (H(2)S) emissions during slurry treatment and subsequent undisturbed storage. The study was conducted in an experimental setup consisting of nine dynamic flux chambers. Three pH levels (pH = 6.0, pH = 5.8 and pH = 5.5), combined with short-term aeration and venting (with an inert gas) treatments were studied. Acidification reduced average NH(3) emissions from swine slurry stored after acidification treatment compared to emissions during storage of non-acidified slurry. The reduction were 50%, 62% and 77% when pH was reduce to 6.0, 5.8 and 5.5, respectively. However, it had no significant effect on average CO(2) and H(2)S emissions during storage of slurry after acidification. Aeration of the slurry for 30 min had no effect on average NH(3), CO(2) and H(2)S emissions both during the process and from stored slurry after venting treatments. During aeration treatment, the NH(3), CO(2) and H(2)S release pattern observed was related to the liquid turbulence caused by the gas bubbles rather than to biological oxidation processes in this study. Copyright © 2012 Elsevier Ltd. All rights reserved.

Process for the production of liquid hydrocarbons

DOEpatents

Bhatt, Bharat Lajjaram; Engel, Dirk Coenraad; Heydorn, Edward Clyde; Senden, Matthijis Maria Gerardus

2006-06-27

The present invention concerns a process for the preparation of liquid hydrocarbons which process comprises contacting synthesis gas with a slurry of solid catalyst particles and a liquid in a reactor vessel by introducing the synthesis gas at a low level into the slurry at conditions suitable for conversion of the synthesis gas into liquid hydrocarbons, the solid catalyst particles comprising a catalytic active metal selected from cobalt or iron on a porous refractory oxide carrier, preferably selected from silica, alumina, titania, zirconia or mixtures thereof, the catalyst being present in an amount between 10 and 40 vol. percent based on total slurry volume liquids and solids, and separating liquid material from the solid catalyst particles by using a filtration system comprising an asymmetric filtration medium (the selective side at the slurry side), in which filtration system the average pressure differential over the filtration medium is at least 0.1 bar, in which process the particle size distribution is such that at least a certain amount of the catalyst particles is smaller than the average pore size of the selective layer of the filtration medium. The invention also comprises an apparatus to carry out the process described above.

Pseudoplasticity of Propellant Slurry with Varied Aluminium Content for Castability Development

NASA Astrophysics Data System (ADS)

Restasari, A.; Budi, R. S.; Hartaya, K.

2018-04-01

The modification of the percentage of aluminium is necessary to obtain certain specific impulse. But, it affects the pseudoplasticity of propellant in elapsed time that is important in casting. Therefore, this research attempts to investigate the pseudoplasticity of propellant slurry with varied aluminium contents and as time elapsed, the range of percentage of aluminium and time that allows propellant slurry to be well processed. The methods include measuring the viscosity of propellant slurries that contain 6, 8, 10, 12, 14, 16 and 18% of aluminium at varied shear rates until 40 minutes after mixing by using Brookfield viscometer. The graphs of viscosity versus shear rate were made to determine pseudoplasticity index. After that, the graph volume fraction versus pseudoplasticity index were made to be investigated. It is concluded that the more aluminium contents, the slurries with 6 to 12% aluminium contents exhibit more pseudoplastic behaviour, but the slurries with 12 to 16% aluminium exhibit less pseudoplastic. While, slurry of 18% aluminium exhibit high pseudoplasticity. In the correlation with the time, the slurry compositions of 6, 8, 14, 16% aluminium become more pseudoplastic as time elapsed. While, for compositions of 10, 12 and 18% aluminium, the trend becomes contrary. Based on the pseudoplasticity index, propellant slurries that contain 10 and 14% of aluminium are suitable for pressure casting. While for slurries with 6, 8 and 16% of aluminium are also suitable for vacuum casting. All of those suitability are possesed until 40 minutes after mixing. While, the composition of slurries that contain 12 and 18% of aluminium need to be modified to enhanced its castability.

Results from tests of TFL Hydragard sampling loop

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steimke, J.L.

When the Defense Waste Processing Facility (DWPF) is operational, processed radioactive sludge will be transferred in batches to the Slurry Mix Evaporator (SME), where glass frit will be added and the contents concentrated by boiling. Batches of the slurry mixture are transferred from the SME to the Melter Feed Tank (MFT). Hydragard{reg_sign} sampling systems are used on the SME and the MFT for collecting slurry samples in vials for chemical analysis. An accurate replica of the Hydragard sampling system was built and tested in the thermal Fluids Laboratory (TFL) to determine the hydragard accuracy. It was determined that the originalmore » Hydragard valve frequently drew a non-representative sample stream through the sample vial that ranged from frit enriched to frit depleted. The Hydragard valve was modified by moving the plunger and its seat backwards so that the outer surface of the plunger was flush with the inside diameter of the transfer line when the valve was open. The slurry flowing through the vial accurately represented the composition of the slurry in the reservoir for two types of slurries, different dilution factors, a range of transfer flows and a range of vial flows. It was then found that the 15 ml of slurry left in the vial when the Hydragard valve was closed, which is what will be analyzed at DWPF, had a lower ratio of frit to sludge as characterized by the lithium to iron ratio than the slurry flowing through it. The reason for these differences is not understood at this time but it is recommended that additional experimentation be performed with the TFL Hydragard loop to determine the cause.« less

Experimental Evaluation of Cement Replacement Fillers on the Performance of Slurry Seal

NASA Astrophysics Data System (ADS)

Fakhri, Mansour; Alrezaei, Hossein Ali; Naji Almasi, Soroush

2016-10-01

Reducing the level of roads service is a process that starts from the first day of the operation of road and the slope of deterioration curve of road sustainability becomes faster with the passage of time. After building the road, adopting an economic approach in order to maintain the road is very important. Slurry seal as one type of protective asphalts that works by sealing inactive cracks of the road and increasing skid resistance is the most effective types of restoration with environmentally friendly behaviour. Fillers are responsible for adjusting set time in slurry seal. Cement is the most common filler used in slurry seal. Cements having suitable properties as a filler, has a very energy demanding manufacturing process and a notable amount of energy is used for manufacturing cement in the country annually. On the other hand, manufacturing process and application of cement have increased levels of pollutant gases, followed by significant environmental pollution. So in this study other options as a filler such as hydrated lime, stone powder and the slag from iron melting furnace were compared with two common types of cement (Portland and type-v cement) in the mixtures of slurry seal by wet abrasion and cohesion tests. Results indicated that, in both tests, lime and slag fillers had behaviours close to the cement filler.

Slurry Erosive Wear Evaluation of HVOF-Spray Cr2O3 Coating on Some Turbine Steels

NASA Astrophysics Data System (ADS)

Goyal, Deepak Kumar; Singh, Harpreet; Kumar, Harmesh; Sahni, Varinder

2012-09-01

In this study, Cr2O3 coatings were deposited on CF8M and CA6NM turbine steels by high-velocity oxy-fuel (HVOF)-spray process and analyzed with regard to their performance under slurry erosion conditions. High Speed Erosion Test Rig was used for slurry erosion tests, and the effects of three parameters, namely, average particle size, speed (rpm), and slurry concentration on slurry erosion of these materials were investigated. SEM micrographs on the surface of samples, before and after slurry erosion tests, were taken to study the erosion mechanism. For the uncoated steels, CA6NM steel showed better erosion resistance in comparison with CF8M steel. The HVOF-sprayed Cr2O3-coated CF8M and CA6NM steels showed better slurry erosion resistance in comparison with their uncoated counterparts. It may be due to the higher hardness as a result of HVOF-sprayed Cr2O3 coating in comparison with the uncoated CF8M and CA6NM steels.

Treatment Of Metal-Mine Effluents By Limestone Neutralization And Calcite Co-Precipitation

EPA Science Inventory

The U.S. Geological Survey - Leetown Science Center and the Colorado School of Mines have developed a remediation process for the treatment of metals in circumneutral mining influenced waters. The process involves treatment with a pulsed limestone bed (PLB) system, followed by c...

Tidal rhythmites infine-grained Carboniferous limestones, U.S.A.

USGS Publications Warehouse

Archer, A.W.; Feldman, H.R.

1994-01-01

Analyses of fine-grained limestones reveals that many exhibit fine-scale laminations. Laminations can be normally graded and consist of a coarser-grained lower part and a finer-grained upper part. The upper part can also contain finely disseminated organic material. Despite the similarities of such graded laminae to yearly varves and turbidites, it can be demonstrated by use of laminae-thickness periodicities that some graded laminae are reasonably interpreted as the product of tidal processes. Within siliciclastic systems, modern analogues of such processes are available for comparisons. In fine-grained facies of the Salem Limestone (Visean; Indiana, U.S.A.), periodicities observed within sequential-laminae thicknesses indicate a dominant control by neap-spring tidal processes. Similarly, laminae within limestones of the vertebrate-bearing Hamilton paleochannel (Stephanian; Kansas, U.S.) exhibit similar features, including fine-scale tidal bundles. This limestone is noted for the abundance of articulated fish fossils. Carbonates containing articulated fish from the Wild Cow Formation (Stephanian; New Mexico, U.S.), exhibit diffuse laminations; however, closely associated siliciclastic mudstones contain laminae that exhibit tidal periodicities. There are many similarities between tidal periodicities and patterns of lamination thicknesses of these rocks. A tidal interpretation for these rocks allows for localized, very rapid rates of deposition. Such rapid deposition may, in part, help to explain how articulated fish and other vertebrates can become preserved within such fine-grained limestones. ?? 1994.

Analysis and Evaluation of Processes and Equipment in Tasks 2 and 4 of the Low-cost Solar Array Project

NASA Technical Reports Server (NTRS)

Goldman, H.; Wolf, M.

1978-01-01

The significant economic data for the current production multiblade wafering and inner diameter slicing processes were tabulated and compared to data on the experimental and projected multiblade slurry, STC ID diamond coated blade, multiwire slurry and crystal systems fixed abrasive multiwire slicing methods. Cost calculations were performed for current production processes and for 1982 and 1986 projected wafering techniques.

Process for selective grinding of coal

DOEpatents

Venkatachari, Mukund K.; Benz, August D.; Huettenhain, Horst

1991-01-01

A process for preparing coal for use as a fuel. Forming a coal-water slurry having solid coal particles with a particle size not exceeding about 80 microns, transferring the coal-water slurry to a solid bowl centrifuge, and operating same to classify the ground coal-water slurry to provide a centrate containing solid particles with a particle size distribution of from about 5 microns to about 20 microns and a centrifuge cake of solids having a particle size distribution of from about 10 microns to about 80 microns. The classifer cake is reground and mixed with fresh feed to the solid bowl centrifuge for additional classification.

Process and apparatus for coal hydrogenation

DOEpatents

Ruether, John A.; Simpson, Theodore B.

1991-01-01

In a coal liquefaction process an aqueous slurry of coal is prepared containing a dissolved liquefaction catalyst. A small quantity of oil is added to the slurry and then coal-oil agglomerates are prepared by agitation of the slurry at atmospheric pressure. The resulting mixture is drained of excess water and dried at atmospheric pressure leaving catalyst deposited on the agglomerates. The agglomerates then are fed to an extrusion device where they are formed into a continuous ribbon of extrudate and fed into a hydrogenation reactor at elevated pressure and temperature. The catalytic hydrogenation converts the extrudate primarily to liquid hydrocarbons in the reactor. The liquid drained in recovering the agglomerates is recycled.

Water quality changes in acid mine drainage streams in Gangneung, Korea, 10 years after treatment with limestone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shim, Moo Joon; Choi, Byoung Young; Lee, Giehyeon

To determine the long-term effectiveness of the limestone treatment for acid mine drainage (AMD) in Gangneung, Korea, we investigated the elemental distribution in streams impacted by AMD and compared the results of previous studies before and approximately 10 years after the addition of limestone. Addition of limestone in 1999 leads to a pH increase in 2008, and with the exception of Ca, the elemental concentrations (e.g., Fe, Mn, Mg, Sr, Ni, Zn, S) in the streams decreased. The pH was 2.5–3 before the addition of limestone and remained stable at around 4.5–5 from 2008 to 2011, suggesting the reactivity ofmore » the added limestone was diminished and that an alternative approach is needed to increase the pH up to circumneutral range and maintain effective long-term treatment. To identify the processes causing the decrease in the elemental concentrations, we also examined the spatial (approximately 7 km) distribution over three different types of streams affected by the AMD. Lastly, the elemental distribution was mainly controlled by physicochemical processes including redox reactions, dilution on mixing, and co-precipitation/adsorption with Fe (hydr)oxides.« less

Water quality changes in acid mine drainage streams in Gangneung, Korea, 10 years after treatment with limestone

DOE PAGES

Shim, Moo Joon; Choi, Byoung Young; Lee, Giehyeon; ...

2015-09-28

To determine the long-term effectiveness of the limestone treatment for acid mine drainage (AMD) in Gangneung, Korea, we investigated the elemental distribution in streams impacted by AMD and compared the results of previous studies before and approximately 10 years after the addition of limestone. Addition of limestone in 1999 leads to a pH increase in 2008, and with the exception of Ca, the elemental concentrations (e.g., Fe, Mn, Mg, Sr, Ni, Zn, S) in the streams decreased. The pH was 2.5–3 before the addition of limestone and remained stable at around 4.5–5 from 2008 to 2011, suggesting the reactivity ofmore » the added limestone was diminished and that an alternative approach is needed to increase the pH up to circumneutral range and maintain effective long-term treatment. To identify the processes causing the decrease in the elemental concentrations, we also examined the spatial (approximately 7 km) distribution over three different types of streams affected by the AMD. Lastly, the elemental distribution was mainly controlled by physicochemical processes including redox reactions, dilution on mixing, and co-precipitation/adsorption with Fe (hydr)oxides.« less

Characterization of limestone reacted with acid-mine drainage in a pulsed limestone bed treatment system at the Friendship Hill National Historical Site, Pennsylvania, USA

USGS Publications Warehouse

Hammarstrom, J.M.; Sibrell, P.L.; Belkin, H.E.

2003-01-01

Armoring of limestone is a common cause of failure in limestone-based acid-mine drainage (AMD) treatment systems. Limestone is the least expensive material available for acid neutralization, but is not typically recommended for highly acidic, Fe-rich waters due to armoring with Fe(III) oxyhydroxide coatings. A new AMD treatment technology that uses CO2 in a pulsed limestone bed reactor minimizes armor formation and enhances limestone reaction with AMD. Limestone was characterized before and after treatment with constant flow and with the new pulsed limestone bed process using AMD from an inactive coal mine in Pennsylvania (pH = 2.9, Fe = 150 mg/l, acidity = 1000 mg/l CaCO3). In constant flow experiments, limestone is completely armored with reddish-colored ochre within 48 h of contact in a fluidized bed reactor. Effluent pH initially increased from the inflow pH of 2.9 to over 7, but then decreased to 6 during operation. Limestone removed from a pulsed bed pilot plant is a mixture of unarmored, rounded and etched limestone grains and partially armored limestone and refractory mineral grains (dolomite, pyrite). The ???30% of the residual grains in the pulsed flow reactor that are armored have thicker (50- to 100-??m), more aluminous coatings and lack the gypsum rind that develops in the constant flow experiment. Aluminium-rich zones developed in the interior parts of armor rims in both the constant flow and pulsed limestone bed experiments in response to pH changes at the solid/solution interface. ?? 2003 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Josephson, Gary B.; Geeting, John GH; Bredt, Ofelia P.

Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Waste Treatment Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed, and operated as part of a plan to respond to issue M12, "Undemonstrated Leaching Processes." The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEPmore » also includes non-prototypic ancillary equipment to support the core processing. Two operating scenarios are currently being evaluated for the ultrafiltration process (UFP) and leaching operations. The first scenario has caustic leaching performed in the UFP-2 ultrafiltration feed vessels (i.e., vessel UFP-VSL-T02A in the PEP; and vessels UFP-VSL-00002A and B in the WTP PTF). The second scenario has caustic leaching conducted in the UFP-1 ultrafiltration feed preparation vessels (i.e., vessels UFP-VSL-T01A and B in the PEP; vessels UFP-VSL-00001A and B in the WTP PTF). In both scenarios, 19-M sodium hydroxide solution (NaOH, caustic) is added to the waste slurry in the vessels to leach solid aluminum compounds (e.g., gibbsite, boehmite). Caustic addition is followed by a heating step that uses direct injection of steam to accelerate the leach process. Following the caustic leach, the vessel contents are cooled using vessel cooling jackets and/or external heat exchangers. The main difference between the two scenarios is that for leaching in UFP-1, the 19-M NaOH is added to un-concentrated waste slurry (3-8 wt% solids), while for leaching in UFP-2, the slurry is concentrated to nominally 20 wt% solids using cross-flow ultrafiltration before the addition of caustic. In both scenarios, following the caustic leach, the slurry was then concentrated to 17 wt% and washed with inhibited water to remove NaOH and other soluble salts. Next, the slurry was oxidatively leached using sodium permanganate to solubilize chrome. The slurry was then washed to remove the dissolved chrome and concentrated.« less

Treatment Of Metal-Mine Effluents By Limestone Neutralization And Calcite Co-Precipitation (Presentation)

EPA Science Inventory

The U.S. Geological Survey - Leetown Science Center and the Colorado School of Mines have developed a remediation process for the treatment of metals in circumneutral mining influenced waters. The process involves treatment with a pulsed limestone bed (PLB) system, followed by c...

Physio-Microstructural Properties of Aerated Cement Slurry for Lightweight Structures

PubMed Central

Salem, Talal; Hamadna, Sameer; Darsanasiri, A. G. N. D.; Soroushian, Parviz; Balchandra, Anagi; Al-Chaar, Ghassan

2018-01-01

Cementitious composites, including ferrocement and continuous fiber reinforced cement, are increasingly considered for building construction and repair. One alternative in processing of these composites is to infiltrate the reinforcement (continuous fibers or chicken mesh) with a flowable cementitious slurry. The relatively high density of cementitious binders, when compared with polymeric binders, are a setback in efforts to introduce cementitious composites as lower-cost, fire-resistant, and durable alternatives to polymer composites. Aeration of the slurry is an effective means of reducing the density of cementitious composites. This approach, however, compromises the mechanical properties of cementitious binders. An experimental program was undertaken in order to assess the potential for production of aerated slurry with a desired balance of density, mechanical performance, and barrier qualities. The potential for nondestructive monitoring of strength development in aerated cementitious slurry was also investigated. This research produced aerated slurries with densities as low as 0.9 g/cm3 with viable mechanical and barrier qualities for production of composites. The microstructure of these composites was also investigated. PMID:29649163

Physio-Microstructural Properties of Aerated Cement Slurry for Lightweight Structures.

PubMed

Almalkawi, Areej T; Salem, Talal; Hamadna, Sameer; Darsanasiri, A G N D; Soroushian, Parviz; Balchandra, Anagi; Al-Chaar, Ghassan

2018-04-12

Cementitious composites, including ferrocement and continuous fiber reinforced cement, are increasingly considered for building construction and repair. One alternative in processing of these composites is to infiltrate the reinforcement (continuous fibers or chicken mesh) with a flowable cementitious slurry. The relatively high density of cementitious binders, when compared with polymeric binders, are a setback in efforts to introduce cementitious composites as lower-cost, fire-resistant, and durable alternatives to polymer composites. Aeration of the slurry is an effective means of reducing the density of cementitious composites. This approach, however, compromises the mechanical properties of cementitious binders. An experimental program was undertaken in order to assess the potential for production of aerated slurry with a desired balance of density, mechanical performance, and barrier qualities. The potential for nondestructive monitoring of strength development in aerated cementitious slurry was also investigated. This research produced aerated slurries with densities as low as 0.9 g/cm³ with viable mechanical and barrier qualities for production of composites. The microstructure of these composites was also investigated.

The use of functionalized monoalkyl phosphates and phosphonates in the colloidal processing of oxide ceramic powders

NASA Astrophysics Data System (ADS)

Radsick, Timothy Carl

The purpose of this study was to develop phosphorous-based chemicals that could be used to modify the interparticle pair potential of several oxide ceramic particles, thereby enabling their use in colloidal processing schemes. Several procedures for the synthesis of 11-12 carbon alpha,o-functionalized monoalkyl phosphates and phosphonates were developed. Because of its simplicity and its use of mild reagents, a procedure based on the Michaelis-Arbuzov rearrangement was selected to produce the bulk of the chemicals used in this study. Carboxyl- and hydroxyl-terminated monoalkyl phosphonates were adsorbed onto alumina and zirconia powders using either aqueous-based or solvent-based methods to produce a monolayer of "brushlike" steric molecules. In the aqueous-based methods, powders were processed at pH values below their isoelectric point in order to produce a positive charge on the powder, thereby attracting the negatively charged phosphate or phosphonate group onto the powder surface to form the steric monolayer. In solvent-based methods, powder was suspended in an acetone solution of the phosphonates, heated at reflux, washed, dried and heat treated at 120°C under vacuum. The zeta potential of the coated powders was measured to quantify the degree of steric layer adsorption and the shift in the isoelectric point. Slurries of coated alumina and zirconia were prepared having 20 vol % powder. Rheological behavior was studied by measuring viscosity as a function of shear rate for slurries of various pH values and counterion concentrations. Slurries with powder processed via the solvent method were the least sensitive to changes in slurry pH and were straightforward to prepare. It is thought that the solvent-based coating procedure produced a stronger, multi-dentate powder-phosphonate bond than that of the aqueous-based procedure. Dispersed and coagulated slurries were able to be prepared over a wide pH range, including at the isoelectric point of the uncoated powders where a flocculated slurry would typically occur. Slurries were consolidated using pressure filtration. Compressive stress-strain behavior and packing efficiencies were determined. Through consolidation, powder volume fraction was increased to a maximum of 56%, yet through vibration the slurry could be induced to flow, enabling its use in Colloidal Isopressing.

Toxicity Evaluation of Pig Slurry Using Luminescent Bacteria and Zebrafish

PubMed Central

Chen, Wenyan; Cai, Qiang; Zhao, Yuan; Zheng, Guojuan; Liang, Yuting

2014-01-01

Biogas slurry has become a serious pollution problem and anaerobic digestion is widely applied to pig manure treatment for environmental protection and energy recovery. To evaluate environmental risk of the emission of biogas slurry, luminescent bacteria (Vibrio fischeri), larvae and embryos of zebrafish (Danio rerio) were used to detect the acute and development toxicity of digested and post-treated slurry. Then the ability of treatment process was evaluated. The results showed that digested slurry displayed strong toxicity to both zebrafish and luminescent bacteria, while the EC50 for luminescent bacteria and the LC50 for larvae were only 6.81% (v/v) and 1.95% (v/v) respectively, and embryonic development was inhibited at just 1% (v/v). Slurry still maintained a high level of toxicity although it had been treated by membrane bioreactor (MBR), while the LC50 of larvae was 75.23% (v/v) and there was a little effect on the development of embryos and V. fischeri; the results also revealed that the zebrafish larvae are more sensitive than embryos and luminescent bacteria to pig slurry. Finally, we also found the toxicity removal rate was higher than 90% after the treatment of MBR according to toxicity tests. In conclusion, further treatment should be used in pig slurry disposal or reused of final effluent. PMID:24995598

Accelerated weathering of limestone for CO2 mitigation opportunities for the stone and cement industries

USGS Publications Warehouse

Langer, W.H.; Juan, C.A.S.; Rau, G.H.; Caldeira, K.

2009-01-01

Large amounts of limestone fines coproduced during the processing of crushed limestone may be useful in the sequestration of carbon dioxide (CO 2). Accelerated weathering of limestone (AWL) is proposed as a low-tech method to capture and sequester CO2 from fossil fuel-fired power plants and other point-sources such as cement manufacturing. AWL reactants are readily available, inexpensive, and environmentally benign. Waste CO 2 is hydrated with water to produce carbonic acid, which then reacts with and is neutralized by limestone fines, thus converting CO2 gas to dissolved calcium bicarbonate. AWL waste products can be disposed of in the ocean. Feasibility requires access to an inexpensive source of limestone and to seawater, thus limiting AWL facilities within about 10 km of the coastline. The majority of U.S. coastal power generating facilities are within economical transport distance of limestone resources. AWL presents opportunities for collaborative efforts among the crushed stone industry, electrical utilities, cement manufactures, and research scientists.

Microwave applicator for in-drum processing of radioactive waste slurry

DOEpatents

White, Terry L.

1994-01-01

A microwave applicator for processing of radioactive waste slurry uses a waveguide network which splits an input microwave of TE.sub.10 rectangular mode to TE.sub.01 circular mode. A cylindrical body has four openings, each receiving 1/4 of the power input. The waveguide network includes a plurality of splitters to effect the 1/4 divisions of power.

Method for producing oxygen from lunar materials

NASA Technical Reports Server (NTRS)

Sullivan, Thomas A. (Inventor)

1993-01-01

This invention is related to producing oxygen from lunar or Martian materials, particularly from lunar ilmenite in situ. The process includes producing a slurry of the minerals and hot sulfuric acid, the acid and minerals reacting to form sulfates of the metal. Water is added to the slurry to dissolve the minerals into an aqueous solution, the first aqueous solution is separated from unreacted minerals from the slurry, and the aqueous solution is electrolyzed to produce the metal and oxygen.

Note: Evaluation of slurry particle size analyzers for chemical mechanical planarization process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jang, Sunjae; Kulkarni, Atul; Qin, Hongyi

In the chemical mechanical planarization (CMP) process, slurry particle size is important because large particles can cause defects. Hence, selection of an appropriate particle measuring system is necessary in the CMP process. In this study, a scanning mobility particle sizer (SMPS) and dynamic light scattering (DLS) were compared for particle size distribution (PSD) measurements. In addition, the actual particle size and shape were confirmed by transmission electron microscope (TEM) results. SMPS classifies the particle size according to the electrical mobility, and measures the particle concentration (single particle measurement). On the other hand, the DLS measures the particle size distribution bymore » analyzing scattered light from multiple particles (multiple particle measurement). For the slurry particles selected for evaluation, it is observed that SMPS shows bi-modal particle sizes 30 nm and 80 nm, which closely matches with the TEM measurements, whereas DLS shows only single mode distribution in the range of 90 nm to 100 nm and showing incapability of measuring small particles. Hence, SMPS can be a better choice for the evaluation of CMP slurry particle size and concentration measurements.« less

SLURRY SOLVENT EXTRACTION PROCESS FOR THE RECOVERY OF METALS FROM SOLID MATERIALS

DOEpatents

Grinstead, R.R.

1959-01-20

A solvent extraction process is described for recovering uranium from low grade uranium bearing minerals such as carnotit or shale. The finely communited ore is made up as an aqueous slurry containing the necessary amount of acid to solubilize the uranium and simultaneously or subsequently contacted with an organic solvent extractant such as the alkyl ortho-, or pyro phosphoric acids, alkyl phosphites or alkyl phosphonates in combination with a diluent such as kerosene or carbon tetrachlorids. The extractant phase is separated from the slurry and treated by any suitable process to recover the uranium therefrom. One method for recovering the uranium comprises treating the extract with aqueous HF containing a reducing agent such as ferrous sulfate, which reduces the uranium and causes it to be precipitated as uranium tetrafluoride.

Colloidal isopressing: A new shaping method for ceramic suspensions

NASA Astrophysics Data System (ADS)

Yu, Benjamin Christopher

Colloidal Isopressing is a new processing method for shaping compacts from particulate suspensions. The study of interparticle interactions within a suspension, and their effect on the overall slurry behavior, has led to the prior discovery of a plastic-to-brittle transition in powder compacts formed by pressure filtration. Colloidal Isopressing utilizes this pressure dependent behavior for slurries with a short-range repulsive potential to rapidly transform plastic consolidated bodies into more complex shapes. The first results are presented for aqueous alumina suspensions where electrostatic double layer repulsion is compressed to short interparticle separations by the addition of ammonium chloride. Consolidation at low pressures produces a high relative density slurry that is plastic and can be extruded into a rubber mold. The application of an hydrostatic pressure forces a small amount of liquid into a porous portion of the mold and pushes particles together into a rigid network. As the pressure is released, the newly formed powder compact will partially separate from the lower modulus rubber mold. The body can then be ejected from the mold, dried, and densified to produce the final ceramic component. Colloidal Isopressing has been successfully modeled as a special case of consolidation via pressure filtration. Theoretical analyses have accurately predicted the time required for the rapid transformation from plastic slurry to elastic powder compact. The effects of slurry composition on processing were studied. The electrolyte concentration, powder particle size, slurry pH, and polymer concentration were shown to alter the flow behavior of filter pressed and liquefied compacts. As the free volume of liquid decreased and/or the relative attraction between particles increased, the concentrated slurry became more difficult to process. Finally, drying of compacts formed by Colloidal Isopressing did not result in any shrinkage during drying, thus allowing for very rapid heating rates to be used. In fact, the drying, burnout, and densification could be combined into one step, with final densities approaching the theoretical limit.

Direct spray drying and microencapsulation of probiotic Lactobacillus reuteri from slurry fermentation with whey.

PubMed

Jantzen, M; Göpel, A; Beermann, C

2013-10-01

Formulations of dietary probiotics have to be robust against process conditions and have to maintain a sufficient survival rate during gastric transit. To increase efficiency of the encapsulation process and the viability of applied bacteria, this study aimed at developing spray drying and encapsulation of Lactobacillus reuteri with whey directly from slurry fermentation. Lactobacillus reuteri was cultivated in watery 20% (w/v) whey solution with or without 0·5% (w/v) yeast extract supplementation in a submerged slurry fermentation. Growth enhancement with supplement was observed. Whey slurry containing c. 10(9)  CFU g(-1) bacteria was directly spray-dried. Cell counts in achieved products decreased by 2 log cycles after drying and 1 log cycle during 4 weeks of storage. Encapsulated bacteria were distinctively released in intestinal milieu. Survival rate of encapsulated bacteria was 32% higher compared with nonencapsulated ones exposed to artificial digestive juice. Probiotic L. reuteri proliferate in slurry fermentation with yeast-supplemented whey and enable a direct spray drying in whey. The resulting microcapsules remain stable during storage and reveal adequate survival in simulated gastric juices and a distinct release in intestinal juices. Exploiting whey as a bacterial substrate and encapsulation matrix within a coupled fermentation and spray-drying process offers an efficient option for industrial production of vital probiotics. © 2013 The Society for Applied Microbiology.

Yield Stress Reduction of DWPF Melter Feed Slurries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stone, M.E.; Smith, M.E.

2007-07-01

The Defense Waste Processing Facility (DWPF) at the Savannah River Site vitrifies High Level Waste for repository internment. The process consists of three major steps: waste pretreatment, vitrification, and canister decontamination/sealing. The HLW consists of insoluble metal hydroxides and soluble sodium salts. The pretreatment process acidifies the sludge with nitric and formic acids, adds the glass formers as glass frit, then concentrates the resulting slurry to approximately 50 weight percent (wt%) total solids. This slurry is fed to the joule-heated melter where the remaining water is evaporated followed by calcination of the solids and conversion to glass. The Savannah Rivermore » National Laboratory (SRNL) is currently assisting DWPF efforts to increase throughput of the melter. As part of this effort, SRNL has investigated methods to increase the solids content of the melter feed to reduce the heat load required to complete the evaporation of water and allow more of the energy available to calcine and vitrify the waste. The process equipment in the facility is fixed and cannot process materials with high yield stresses, therefore increasing the solids content will require that the yield stress of the melter feed slurries be reduced. Changing the glass former added during pretreatment from an irregularly shaped glass frit to nearly spherical beads was evaluated. The evaluation required a systems approach which included evaluations of the effectiveness of beads in reducing the melter feed yield stress as well as evaluations of the processing impacts of changing the frit morphology. Processing impacts of beads include changing the settling rate of the glass former (which effects mixing and sampling of the melter feed slurry and the frit addition equipment) as well as impacts on the melt behavior due to decreased surface area of the beads versus frit. Beads were produced from the DWPF process frit by fire polishing. The frit was allowed to free fall through a flame, then quenched with a water spray. Approximately 90% of the frit was converted to beads by this process. Yield stress reduction was measured by preparing melter feed slurries (using nonradioactive HLW simulants) that contain beads and comparing the yield stress with melter feed containing frit. A second set of tests was performed with beads of various diameters to determine if a decrease in diameter affected the results. Smaller particle size was shown to increase yield stress when frit is utilized. The settling rate of the beads was required to match the settling rate of the frit, therefore a decrease in particle size was anticipated. Settling tests were conducted in water, xanthan gum solutions, and in non-radioactive simulants of the HLW. The tests used time-lapse video-graphy as well as solids sampling to evaluate the settling characteristics of beads compared to frit of the same particle size. A preliminary melt rate evaluation was performed using a dry-fed Melt Rate Furnace (MRF) developed by SRNL. Preliminary evaluation of the impact of beading the frit on the frit addition system were completed by conducting flow loop testing. A recirculation loop was built with a total length of about 30 feet. Pump power, flow rate, outlet pressure, and observations of the flow in the horizontal upper section of the loop were noted. The recirculation flow was then gradually reduced and the above items recorded until settling was noted in the recirculation line. Overall, the data shows that the line pressure increased as the solids were increased for the same flow rate. In addition, the line pressure was higher for Frit 320 than the beads at the same solids level and flow. With the observations, a determination of minimum velocity to prevent settling could be done, but a graph of the line pressures versus velocity for the various tests was deemed to more objective. The graph shows that the inflection point in pressure drop is about the same for the beads and Frit 320. This indicates that the bead slurry would not require higher flows rates than frit slurry at DWPF during transfers. Another key finding was that the pump impeller was not significantly damaged by the bead slurry, while the Frit 320 slurry rapidly destroyed the impeller. Evidence of this was first observed when black particles were seen in the Frit 320 slurry being recirculated and then confirmed by a post-test inspection of the impeller. Finally, the pumping of bead slurry could be recovered even if flow is stopped. The Frit 320 slurry could not be restarted after stopping flow due to the nature of the frit to pack tightly when settled. Beads were shown to represent a significant process improvement versus frit for the DWPF process in lowering yield stress of the melter feed. Lower erosion of process equipment is another expected benefit.« less

Fischer-Tropsch Wastewater Utilization

DOEpatents

Shah, Lalit S.

2003-03-18

The present invention is generally directed to handling the wastewater, or condensate, from a hydrocarbon synthesis reactor. More particularly, the present invention provides a process wherein the wastewater of a hydrocarbon synthesis reactor, such as a Fischer-Tropsch reactor, is sent to a gasifier and subsequently reacted with steam and oxygen at high temperatures and pressures so as to produce synthesis gas. The wastewater may also be recycled back to a slurry preparation stage, where solid combustible organic materials are pulverized and mixed with process water and the wastewater to form a slurry, after which the slurry fed to a gasifier where it is reacted with steam and oxygen at high temperatures and pressures so as to produce synthesis gas.

PROCESS FOR PRODUCING ALKYL ORTHOPHOSPHORIC ACID EXTRACTANTS

DOEpatents

Grinstead, R.R.

1962-01-23

A process is given for producing superior alkyl orthophosphoric acid extractants for use in solvent extraction methods to recover and purify various metals such as uranium and vanadium. The process comprises slurrying P/sub 2/O/ sub 5/ in a solvent diluent such as kerosene, benzene, isopropyl ether, and the like. An alipbatic alcohol having from nine to seventeen carbon atoms, and w- hcrein ihc OH group is situated inward of the terminal carbon atoms, is added to the slurry while the reaction temperature is mainiained below 60 deg C. The alcohol is added in the mole ratio of about 2 to l, alcohol to P/sub 2/O/sub 5/. A pyrophosphate reaotion product is formed in the slurry-alcohol mixture. Subsequently, the pyrophosphate reaction product is hydrolyzed with dilute mineral acid to produce the desired alkyl orthophosphoric aeid extractant. The extraetant may then be separated and utilized in metal-recovery, solvent- extraction processes. (AEC)

Microwave applicator for in-drum processing of radioactive waste slurry

DOEpatents

White, T.L.

1994-06-28

A microwave applicator for processing of radioactive waste slurry uses a waveguide network which splits an input microwave of TE[sub 10] rectangular mode to TE[sub 01] circular mode. A cylindrical body has four openings, each receiving 1/4 of the power input. The waveguide network includes a plurality of splitters to effect the 1/4 divisions of power. 4 figures.

Development of carbon slurry fuels for transportation (hybrid fuels, phase 2)

NASA Technical Reports Server (NTRS)

Ryan, T. W., III; Dodge, L. G.

1984-01-01

Slurry fuels of various forms of solids in diesel fuel are developed and evaluated for their relative potential as fuel for diesel engines. Thirteen test fuels with different solids concentrations are formulated using eight different materials. A variety of properties are examined including ash content, sulfur content, particle size distribution, and rheological properties. Attempts are made to determine the effects of these variations on these fuel properties on injection, atomization, and combustion processes. The slurries are also tested in a single cylinder CLR engine in both direct injection and prechamber configurations. The data includes the normal performance parameters as well as heat release rates and emissions. The slurries perform very much like the baseline fuel. The combustion data indicate that a large fraction (90 percent or more) of the solids are burning in the engine. It appears that the prechamber engine configuration is more tolerant of the slurries than the direct injection configuration.

Treatment of highly polluted groundwater by novel iron removal process.

PubMed

Sim, S J; Kang, C D; Lee, J W; Kim, W S

2001-01-01

The removal of ferrous iron (Fe(II)) in groundwater has been generally achieved by simple aeration, or the addition of an oxidizing agent. Aeration has been shown to be very efficient in insolubilization ferrous iron at a pH level greater than 6.5. In this study, pH was maintained over 6.5 using limestone granules under constant aeration to oxidize ferrous iron in groundwater in a limestone packed column. A sedimentation unit coupled with a membrane filtration was also developed to precipitate and filtrate the oxidized ferric compound simultaneously. Several bench-scale studies, including the effects of the limestone granule sizes, amounts and hydraulic retention time on iron removal in the limestone packed column were investigated. It was found that 550 g/L of the 7-8 mesh size limestone granules, and 20 min of hydraulic retention time in the limestone packed column, were necessary for the sufficient oxidation of 40 mg/L of iron(II) in groundwater. Long-term operation was successfully achieved in contaminated waters by removing the iron deposits on the surface of the limestone granule by continuous aeration from the bottom of the column. Periodic reverse flow helped to remove caking and fouling of membrane surface caused by the continuous filtration. Recycling of the treated water from the membrane right after reverse flow operation made possible an admissible limit of iron concentration of the treated water for drinking. The pilot-scale process was constructed and has been tested in the rural area of Korea.

Characterization of Diarrheagenic Escherichia coli Isolated in Organic Waste Products (Cattle Fecal Matter, Manure and, Slurry) from Cattle's Markets in Ouagadougou, Burkina Faso.

PubMed

Bako, Evariste; Kagambèga, Assèta; Traore, Kuan Abdoulaye; Bagre, Touwendsida Serge; Ibrahim, Hadiza Bawa; Bouda, Soutongnooma Caroline; Bonkoungou, Isidore Juste Ouindgueta; Kaboré, Saidou; Zongo, Cheikna; Traore, Alfred Sababenejo; Barro, Nicolas

2017-09-22

Cattle farming can promote diarrheal disease transmission through waste, effluents or cattle fecal matter. The study aims to characterize the diarrheagenic Escherichia coli (DEC) isolated from cattle feces, manure in the composting process and slurry, collected from four cattle markets in Ouagadougou. A total of 585 samples (340 cattle feces, 200 slurries and 45 manures in the composting process) were collected from the four cattle markets between May 2015 and May 2016. A multiplex Polymerase Chain Reaction (PCR), namely 16-plex PCR, was used to screen simultaneously the virulence genes specific for shiga toxin-producing E. coli (STEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC) and enteroaggregative E. coli (EAEC). DEC was detected in 10.76% of samples. ETEC was the most prevalent (9.91%). STEC and EAEC have been observed with the same rate (0.51%). ETEC were detected in 12.64% of cattle feces, in 6.66% of manure in the composting process and in 5% of slurry. STEC were detected in 0.58% of cattle feces and in 2.22% of manure in the composting process. EAEC was detected only in 1% of slurry and in 2.22% of manure in the composting process. ETEC strains were identified based on estIa gene and/or estIb gene and/or elt gene amplification. Of the 58 ETEC, 10.34% contained astA , 17.24% contained elt , 3.44% contained estIa and 79.31% contained estIb . The two positive EAEC strains contained only the aggR gene, and the third was positive only for the pic gene. The results show that effluent from cattle markets could contribute to the spreading of DEC in the environment in Burkina Faso.

Oxidative degradation and toxicity reduction of trichloroethylene (TCE) in water using TiO2/solar light: comparative study of TiO2 slurry and immobilized systems.

PubMed

Cho, Il-Hyoung; Park, Jae-Hong; Kim, Young-Gyu

2005-01-01

A solar-driven, photocatalyzed degradation system using TiO2 slurry and immobilized systems was constructed and applied to the degradation of trichloroethylene (TCE) contaminated water using TiO2 with solar light. The experiments were carried out under constant weather conditions on a sunny day. Solar photocatalytic treatment efficiency of the solar light/TiO2 slurry system was compared with that of the solar light/TiO2 immobilized system. The operation of the solar light/TiO2 slurry and immobilized systems showed 100% (TiO2 slurry system), 80% (TiO2 immobilized system) degradation of the TCE after 6 h, with a chloride production yield of approximately 89% (TiO2 slurry system), 72% (TiO2 immobilized system). The oxidants such as H2O2 and S2O8(2-) in the TiO2 slurry and immobilized systems increased TCE degradation rate by suppressing the electron/hole recombination process. The degradation rate and relative toxicity reduction of TCE followed the order of solar light/TiO2 slurry + S2O8(2-) > solar light/TiO2 slurry + H2O2 > solar light/TiO2 immobilized + S2O8(2-) > solar light/TiO2 slurry > solar light/TiO2 immobilized + H2O2 > solar light/TiO2 immobilized. Finally, following to the toxicity result, the acute toxicity was reduced by below toxicity endpoint (EC50 concentration) following the treatment. It means that many of the metabolites of TCE reduction are less toxic to Vibrio fischeri than the parent compound. Based on these results, TCE can be efficiently and safely treated in a solar-driven, photocatalyzed degradation system.

Dioxin and trace metal emissions from combustion of carbonized RDF slurry fuels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klosky, M.; Fisher, M.; Singhania, A.

1997-12-01

In 1994, the U.S. generated approximately 209 million tons of Municipal Solid Waste (MSW), with 61% landfilled, 24% recycled, and 15% processed through Municipal Waste Combustion (MWC). In order to divert a larger portion of this generated MSW from landfills, MWC will have to play a growing role in MSW disposal. However, recently promulgated New Source Performance Standards (NSPS) for MWC will add an additional financial burden, through mandated emission reductions and air pollution control technologies, to an already financially pressured MWC marketplace. In the past, Refuse Derived Fuel (RDF), a solid fuel produced from MSW, has been fired inmore » industrial and coal boilers as an alternative means of MWC. While lower sulfur dioxide (SO{sub 2}) emissions provided the impetus, firing RDF in industrial and coal boilers frequently suffered from several disadvantages including increased solids handling, increased excess air requirements, increased air emissions, increased slag formation in the boiler, and higher fly ash resistivity. This paper summarizes the latest emissions and combustion tests with the carbonized RDF slurry fuel. With EnerTech`s SlurryCarb{trademark} process, a pumpable slurry of RDF is continuously pressurized with a pump to between 1200 and 2500 psi. The RDF slurry is pressurized above the saturated steam curve to maintain a liquid state when the slurry is heated to approximately 480-660{degrees}F. Slurry pressure and temperature then are maintained for less than 30 minutes in plug-flow reactors. At this temperature and pressure, oxygen functional groups in the molecular structure of the RDF are split off as carbon dioxide gas. This evolved carbon dioxide gas comprises a significant weight percentage of the feed RDF, but only a minimal percentage of the heating value.« less

Liquefaction processes and systems and liquefaction process intermediate compositions

DOEpatents

Schmidt, Andrew J.; Hart, Todd R.; Billing, Justin M.; Maupin, Gary D.; Hallen, Richard T.; Anderson, Daniel B.

2014-07-12

Liquefaction processes are provided that can include: providing a biomass slurry solution having a temperature of at least 300.degree. C. at a pressure of at least 2000 psig; cooling the solution to a temperature of less than 150.degree. C.; and depressurizing the solution to release carbon dioxide from the solution and form at least part of a bio-oil foam. Liquefaction processes are also provided that can include: filtering the biomass slurry to remove particulates; and cooling and depressurizing the filtered solution to form the bio-oil foam. Liquefaction systems are provided that can include: a heated biomass slurry reaction zone maintained above 300.degree. C. and at least 2000 psig and in continuous fluid communication with a flash cooling/depressurization zone maintained below 150.degree. C. and between about 125 psig and about atmospheric pressure. Liquefaction systems are also provided that can include a foam/liquid separation system. Liquefaction process intermediate compositions are provided that can include a bio-oil foam phase separated from an aqueous biomass solids solution.

SLIP CASTING METHOD

DOEpatents

Allison, A.G.

1959-09-01

S>A process is described for preparing a magnesium oxide slip casting slurry which when used in conjunction with standard casting techniques results in a very strong "green" slip casting and a fired piece of very close dimensional tolerance. The process involves aging an aqueous magnestum oxide slurry, having a basic pH value, until it attains a specified critical viscosity at which time a deflocculating agent is added without upsetting the basic pH value.

Processes and catalysts for conducting fischer-tropsch synthesis in a slurry bubble column reactor

DOEpatents

Singleton, Alan H.; Oukaci, Rachid; Goodwin, James G.

1999-01-01

Processes and catalysts for conducting Fischer-Tropsch synthesis in a slurry bubble column reactor (SBCR). One aspect of the invention involves the use of cobalt catalysts without noble metal promotion in an SBCR. Another aspect involves using palladium promoted cobalt catalysts in an SBCR. Methods for preparing noble metal promoted catalysts via totally aqueous impregnation and procedures for producing attrition resistant catalysts are also provided.

Iron-carbon compacts and process for making them

DOEpatents

Sheinberg, Haskell

2000-01-01

The present invention includes iron-carbon compacts and a process for making them. The process includes preparing a slurry comprising iron powder, furfuryl alcohol, and a polymerization catalyst for initiating the polymerization of the furfuryl alcohol into a resin, and heating the slurry to convert the alcohol into the resin. The resulting mixture is pressed into a green body and heated to form the iron-carbon compact. The compact can be used as, or machined into, a magnetic flux concentrator for an induction heating apparatus.

Cryogenic fractionator gas as stripping gas of fines slurry in a coking and gasification process

DOEpatents

DeGeorge, Charles W.

1981-01-01

In an integrated coking and gasification process wherein a stream of fluidized solids is passed from a fluidized bed coking zone to a second fluidized bed and wherein entrained solid fines are recovered by a scrubbing process and wherein the resulting solids-liquid slurry is stripped with a stripping gas to remove acidic gases, at least a portion of the stripping gas comprises a gas comprising hydrogen, nitrogen and methane separated from the coker products.

Relationship between operational variables, fundamental physics and foamed cement properties in lab and field generated foamed cement slurries

DOE PAGES

Glosser, D.; Kutchko, B.; Benge, G.; ...

2016-03-21

Foamed cement is a critical component for wellbore stability. The mechanical performance of a foamed cement depends on its microstructure, which in turn depends on the preparation method and attendant operational variables. Determination of cement stability for field use is based on laboratory testing protocols governed by API Recommended Practice 10B-4 (API RP 10B-4, 2015). However, laboratory and field operational variables contrast considerably in terms of scale, as well as slurry mixing and foaming processes. Here in this paper, laboratory and field operational processes are characterized within a physics-based framework. It is shown that the “atomization energy” imparted by themore » high pressure injection of nitrogen gas into the field mixed foamed cement slurry is – by a significant margin – the highest energy process, and has a major impact on the void system in the cement slurry. There is no analog for this high energy exchange in current laboratory cement preparation and testing protocols. Quantifying the energy exchanges across the laboratory and field processes provides a basis for understanding relative impacts of these variables on cement structure, and can ultimately lead to the development of practices to improve cement testing and performance.« less

Slurry hydrocracking of Arab heavy vacuum resid with new bifunctional catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rankel, L.A.

1993-12-31

Co-processing coal with hydrogenated vacuum resids can solubilize coal and aid in metals removals from the hydrotreated resid. Several bifunctional NiW catalysts were evaluated for resid hydrocracking in a slurry reactor. Autoclave runs were made to determine whether a hydrogenative metal function (NiW) plus support with cracking activity might be an effective catalyst for high resid 1000F{degrees}{sup +} conversion, H-content enrichment, deS, and demetallation at low coke make. An Arab Heavy 895{degrees}F{sup +} vacuum resid (262 ppm Ni+V, 5.3% S and 24% CCR) was hydrocracked over sulfided and unsulfided NiW catalysts on alumina, silica-alumina, US-Y, etc. at 800{degrees}F and 2000more » psig hydrogen in a batch reactor and compared to oil soluble mixtures of Ni and W homogenous organometallics. Of the catalysts tested here, results indicate that addition of sulfided NiW/aluminum to slurry type processing might improve hydrogenation activity and produce more 1000{degrees}F{sup +} conversion at a particular severity while generating the low coke make necessary for a continuous process. Once the resid is hydrotreated, coal could be added to the NiW bifunctional catalyst/resid slurry for co-processing.« less

Improving profitability through slurry management: a look at the impact of slurry pH on various glass types

NASA Astrophysics Data System (ADS)

Hooper, Abigail R.; Boffa, Christopher C.; Sarkas, Harry W.; Cureton, Kevin

2015-08-01

When building an optical system, optical fabricators and designers meticulously choose the glass types for their application knowing that each one will have different chemical, thermal and mechanical properties. As the requirements for new optical systems have grown more demanding, the range of available glass types has vastly expanded and the specifications on the produced products have grown tighter. In an attempt to simplify processes and streamline consumable purchases, optical polishing houses often rely on one polishing slurry to manage these vast array of glass types. An unforeseen consequence of these practices can be a reduction in productivity by reduced removal rate, poor yields and frequent rework all translating into higher costs and reduced profitability. In this paper, the authors will examine the impact slurry pH has on glass types of different compositions and chemical, thermal and mechanical properties when using a double-sided polishing process. Experiments will use material removal rate, surface quality, and surface figure to provide insight into improving process control for differing glass types. Further guidance will be provided on how simple on-site monitoring and adjustment can deliver improved profitability on challenging substrates.

Rock Magnetic Cyclostratigraphy of the Mid-Cretaceous Greenhorn Limestone, South-Central Colorado---Influence of Orbitally Induced Climate Variability for Chornostratigraphy

NASA Astrophysics Data System (ADS)

Sellers, T.; Geissman, J. W.; Jackson, J.

2015-12-01

We are testing the hypothesis that depositional processes of the mid-Cretaceous Greenhorn Limestone were influenced by orbitally-driven climate variations using rock magnetic data. Correlation of the data, including anhysteretic remanent magnetization (ARM), magnetic susceptibility, isothermal remanent magnetization in different DC fields to saturation, and hysteresis properties, from three continuously exposed sections of the full Greenhorn Limestone provides detailed spatial distribution for the depositional processes and magnetic mineral climate encoding. The Greenhorn Limestone includes the Lincoln Limestone, Hartland Shale, and the Bridge Creek Limestone members and consists of calcareous shales and limestones representing near maximum depths in the Cretaceous interior seaway. The sections, each about 30 m thick, extend from the upper Graneros Shale, through the Greenhorn Formation, to the lower Carlisle Shale, with samples collected at a two to five cm interval and are located at Badito, CO; north of Redwing, CO; and at the Global boundary Stratotype Section and Point (GSSP) at Lake Pueblo, CO. Our over 1000 samples were hand crushed to granule size pieces and packed into 7cc IODP boxes. Bulk magnetic susceptibility, anhysteretic remanent magnetization (ARM) intensity at different peak AF levels, and isothermal remanent magnetization (IRM) intensity record variations in magnetic mineral concentration and are proxies to determine orbital scale cycles and precise stratigraphic correlation between sections. ARM intensities in a peak field of 100 mT at both sites range between 1.2 x 10-3 and 1.3 x 10-4 A/m and better define periodic variation within the Greenhorn Limestone displaying differences in ferromagnetic mineral content of detrital origin. Magnetic susceptibility, which ranges from 3.5 x 10-2 to 2.86 x 10-3, also shows periodic variation with a strong correlation among the three sections. Saturation IRM at 100 mT ranges from 3.2 x 10-1 to 1.1x 10-2 A/m shows periodic variation with the greatest variability in the Bridge Creek Member. Preliminary spectral analysis of each data set indicates a dominant cyclicity that is of considerably lower frequency than the limestone/shale couplets characteristic of Greenhorn Limestone.

Evaluation of Computational Method of High Reynolds Number Slurry Flow for Caverns Backfilling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bettin, Giorgia

2015-05-01

The abandonment of salt caverns used for brining or product storage poses a significant environmental and economic risk. Risk mitigation can in part be address ed by the process of backfilling which can improve the cavern geomechanical stability and reduce the risk o f fluid loss to the environment. This study evaluate s a currently available computational tool , Barracuda, to simulate such process es as slurry flow at high Reynolds number with high particle loading . Using Barracuda software, a parametric sequence of simu lations evaluated slurry flow at Re ynolds number up to 15000 and loading up tomore » 25%. Li mitations come into the long time required to run these simulation s due in particular to the mesh size requirement at the jet nozzle. This study has found that slurry - jet width and centerline velocities are functions of Re ynold s number and volume fractio n The solid phase was found to spread less than the water - phase with a spreading rate smaller than 1 , dependent on the volume fraction. Particle size distribution does seem to have a large influence on the jet flow development. This study constitutes a first step to understand the behavior of highly loaded slurries and their ultimate application to cavern backfilling.« less

METHOD OF OPERATING A HEAVY WATER MODERATED REACTOR

DOEpatents

Vernon, H.C.

1962-08-14

A method of removing fission products from the heavy water used in a slurry type nuclear reactor is described. According to the process the slurry is steam distilled with carbon tetrachloride so that at least a part of the heavy water and carbon tetrachloride are vaporized; the heavy water and carbon tetrachloride are separated; the carbon tetrachloride is returned to the steam distillation column at different points in the column to aid in depositing the slurry particles at the bottom of the column; and the heavy water portion of the condensate is purified. (AEC)

PILOT-SCALE DEMONSTRATION OF A SLURRY-PHASE BIOLOGICAL REACTOR FOR CREOSOTE-CONTAMINATED SOIL - APPLICATION ANALYSIS REPORT

EPA Science Inventory

In support of the U.S. Environmental Protection Agency’s (EPA) Superfund Innovative Technology Evaluation (SITE) Program, a pilot-scale demonstration of a slurry-phase bioremediation process was performed May 1991 at the EPA’s Test & Evaluation Facility in Cincinnati, OH. In this...

Preparation of prepreg graphite tape with insoluble polymer

NASA Technical Reports Server (NTRS)

Yates, C. I.

1973-01-01

Powdered polymer is finely ground. Second polymer, soluble, is mixed with appropriate solvent. Milled polymer and graphite filaments are added to soluble polymer-solvent solution to create slurry. Slurry is dried, and when ready for processing, the soluble, binder-polymer is removed by heat during precure or cure cycle.

Process for heating coal-oil slurries

DOEpatents

Braunlin, W.A.; Gorski, A.; Jaehnig, L.J.; Moskal, C.J.; Naylor, J.D.; Parimi, K.; Ward, J.V.

1984-01-03

Controlling gas to slurry volume ratio to achieve a gas holdup of about 0.4 when heating a flowing coal-oil slurry and a hydrogen containing gas stream allows operation with virtually any coal to solvent ratio and permits operation with efficient heat transfer and satisfactory pressure drops. The critical minimum gas flow rate for any given coal-oil slurry will depend on numerous factors such as coal concentration, coal particle size distribution, composition of the solvent (including recycle slurries), and type of coal. Further system efficiency can be achieved by operating with multiple heating zones to provide a high heat flux when the apparent viscosity of the gas saturated slurry is highest. Operation with gas flow rates below the critical minimum results in system instability indicated by temperature excursions in the fluid and at the tube wall, by a rapid increase and then decrease in overall pressure drop with decreasing gas flow rate, and by increased temperature differences between the temperature of the bulk fluid and the tube wall. At the temperatures and pressures used in coal liquefaction preheaters the coal-oil slurry and hydrogen containing gas stream behaves essentially as a Newtonian fluid at shear rates in excess of 150 sec[sup [minus]1]. The gas to slurry volume ratio should also be controlled to assure that the flow regime does not shift from homogeneous flow to non-homogeneous flow. Stable operations have been observed with a maximum gas holdup as high as 0.72. 29 figs.

Process for heating coal-oil slurries

DOEpatents

Braunlin, Walter A.; Gorski, Alan; Jaehnig, Leo J.; Moskal, Clifford J.; Naylor, Joseph D.; Parimi, Krishnia; Ward, John V.

1984-01-03

Controlling gas to slurry volume ratio to achieve a gas holdup of about 0.4 when heating a flowing coal-oil slurry and a hydrogen containing gas stream allows operation with virtually any coal to solvent ratio and permits operation with efficient heat transfer and satisfactory pressure drops. The critical minimum gas flow rate for any given coal-oil slurry will depend on numerous factors such as coal concentration, coal particle size distribution, composition of the solvent (including recycle slurries), and type of coal. Further system efficiency can be achieved by operating with multiple heating zones to provide a high heat flux when the apparent viscosity of the gas saturated slurry is highest. Operation with gas flow rates below the critical minimum results in system instability indicated by temperature excursions in the fluid and at the tube wall, by a rapid increase and then decrease in overall pressure drop with decreasing gas flow rate, and by increased temperature differences between the temperature of the bulk fluid and the tube wall. At the temperatures and pressures used in coal liquefaction preheaters the coal-oil slurry and hydrogen containing gas stream behaves essentially as a Newtonian fluid at shear rates in excess of 150 sec.sup. -1. The gas to slurry volume ratio should also be controlled to assure that the flow regime does not shift from homogeneous flow to non-homogeneous flow. Stable operations have been observed with a maximum gas holdup as high as 0.72.

The stability of a novel weakly alkaline slurry of copper interconnection CMPfor GLSI

NASA Astrophysics Data System (ADS)

Yao, Caihong; Wang, Chenwei; Niu, Xinhuan; Wang, Yan; Tian, Shengjun; Jiang, Zichao; Liu, Yuling

2018-02-01

Chemical mechanical polishing (CMP) is one of the important machining procedures of multilayered copper interconnection for GLSI, meanwhile polishing slurry is a critical factor for realizing the high polishing performance such as high planarization efficiency, low surface roughness. The effect of slurry components such as abrasive (colloidal silica), complexing agent (glycine), inhibitor (BTA) and oxidizing agent (H2O2) on the stability of the novel weakly alkaline slurry of copper interconnection CMP for GLSI was investigated in this paper. First, the synergistic and competitive relationship of them in a peroxide-based weakly alkaline slurry during the copper CMP process was studied and the stability mechanism was put forward. Then 1 wt% colloidal silica, 2.5 wt% glycine, 200 ppm BTA, 20 mL/L H2O2 had been selected as the appropriate concentration to prepare copper slurry, and using such slurry the copper blanket wafer was polished. From the variations of copper removal rate, root-mean square roughness (Sq) value with the setting time, it indicates that the working-life of the novel weakly alkaline slurry can reach more than 7 days, which satisfies the requirement of microelectronics further development. Project supported by the Major National Science and Technology Special Projects (No. 2016ZX02301003-004-007), the Professional Degree Teaching Case Foundation of Hebei Province, China (No. KCJSZ2017008), the Natural Science Foundation of Hebei Province, China (No. F2015202267), and the Natural Science Foundation of Tianjin, China (No. 16JCYBJC16100).

Method for fabricating ceramic filaments and high density tape casting method

NASA Technical Reports Server (NTRS)

Collins, Jr., Earl R. (Inventor)

1990-01-01

An apparatus and method is disclosed for fabricating mats of ceramic material comprising preparing a slurry of ceramic particles in a binder/solvent, charging the slurry into a vessel, forcing the slurry from the vessel into spinneret nozzles, discharging the slurry from the nozzles into the path of airjets to enhance the sinuous character of the slurry exudate and to dry it, collecting the filaments on a moving belt so that the filaments overlap each other thereby forming a mat, curing the binder therein, compressing and sintering the mat to form a sintered mat, and crushing the sintered mat to produce filament shaped fragments. A process is also disclosed for producing a tape of densely packed, bonded ceramic particles comprising forming a slurry of ceramic particles and a binder/solvent, applying the slurry to a rotating internal molding surface, applying a large centrifugal force to the slurry to compress it and force excess binder/solvent from the particles, evaporating solvent and curing the binder thereby forming layers of bonded ceramic particles and cured binder, and separating the binder layer from the layer of particles. Multilayers of ceramic particles are cast in an analogous manner on top of previously formed layers. When all of the desired layers have been cast the tape is fired to produce a sintered tape. For example, a three-layer tape is produced having outer layers of highly compressed filament shaped fragments of strontium doped lanthanum (LSM) particles and a center layer of yttria stabilized zicronia (YSZ) particles.

Development of a low-pressure materials pre-treatment process for improved energy efficiency

NASA Astrophysics Data System (ADS)

Lee, Kwanghee; You, Byung Don

2017-09-01

Low pressure materials pre-treatment process has been developed as an alternative to the existing high-temperature sludge drying, limestone calcination, and limonite dehydroxylation. Using the thermodynamic equilibrium relationship between temperature and pressure represented by the Clausius-Clapeyron equation, the operational temperature of these reactions could be lowered at reduced pressure for increased energy efficiency. For industrial sludge drying, the evaporation rate was controlled by interfacial kinetics showing a constant rate with time and significant acceleration in the reaction could be observed with reduced pressure. At this modified reaction rate under low pressure, the rate was also partially controlled by mass transfer. Temperature of limestone calcination was lowered, but the reaction was limited at the calculated equilibrium temperature of the Clausius-Clapeyron equation and slightly higher temperatures were required. The energy consumption during limestone calcination and limonite dehydroxylation were evaluated, where lower processing pressures could enhance the energy efficiency for limestone calcination, but limonite dehydroxylation could not achieve energy-savings due to the greater power consumption of the vacuum pump under lower pressure and reduced temperatures.

Processes and catalysts for conducting Fischer-Tropsch synthesis in a slurry bubble column reactor

DOEpatents

Singleton, A.H.; Oukaci, R.; Goodwin, J.G.

1999-08-17

Processes and catalysts are disclosed for conducting Fischer-Tropsch synthesis in a slurry bubble column reactor (SBCR). One aspect of the invention involves the use of cobalt catalysts without noble metal promotion in an SBCR. Another aspect involves using palladium promoted cobalt catalysts in an SBCR. Methods for preparing noble metal promoted catalysts via totally aqueous impregnation and procedures for producing attrition resistant catalysts are also provided. 1 fig.

Comparing cell viability and ethanol fermentation of the thermotolerant yeast Kluyveromyces marxianus and Saccharomyces cerevisiae on steam-exploded biomass treated with laccase.

PubMed

Moreno, Antonio D; Ibarra, David; Ballesteros, Ignacio; González, Alberto; Ballesteros, Mercedes

2013-05-01

In this study, the thermotolerant yeast Kluyveromyces marxianus CECT 10875 was compared to the industrial strain Saccharomyces cerevisiae Ethanol Red for lignocellulosic ethanol production. For it, whole slurry from steam-exploded wheat straw was used as raw material, and two process configurations, simultaneous saccharification and fermentation (SSF) and presaccharification and simultaneous saccharification and fermentation (PSSF), were evaluated. Compared to S. cerevisiae, which was able to produce ethanol in both process configurations, K. marxianus was inhibited, and neither growth nor ethanol production occurred during the processes. However, laccase treatment of the whole slurry removed specifically lignin phenols from the overall inhibitory compounds present in the slurry and triggered the fermentation by K. marxianus, attaining final ethanol concentrations and yields comparable to those obtained by S. cerevisiae. Copyright © 2012 Elsevier Ltd. All rights reserved.

Method of producing a colloidal fuel from coal and a heavy petroleum fraction

DOEpatents

Longanbach, James R.

1983-08-09

A method is provided for combining coal as a colloidal suspension within a heavy petroleum fraction. The coal is broken to a medium particle size and is formed into a slurry with a heavy petroleum fraction such as a decanted oil having a boiling point of about 300.degree.-550.degree. C. The slurry is heated to a temperature of 400.degree.-500.degree. C. for a limited time of only about 1-5 minutes before cooling to a temperature of less than 300.degree. C. During this limited contact time at elevated temperature the slurry can be contacted with hydrogen gas to promote conversion. The liquid phase containing dispersed coal solids is filtered from the residual solids and recovered for use as a fuel or feed stock for other processes. The residual solids containing some carbonaceous material are further processed to provide hydrogen gas and heat for use as required in this process.

Short residence time coal liquefaction process including catalytic hydrogenation

DOEpatents

Anderson, R.P.; Schmalzer, D.K.; Wright, C.H.

1982-05-18

Normally solid dissolved coal product and a distillate liquid product are produced by continuously passing a feed slurry comprising raw feed coal and a recycle solvent oil and/or slurry together with hydrogen to a preheating-reaction zone, the hydrogen pressure in the preheating-reaction zone being at least 1,500 psig (105 kg/cm[sup 2]), reacting the slurry in the preheating-reaction zone at a temperature in the range of between about 455 and about 500 C to dissolve the coal to form normally liquid coal and normally solid dissolved coal. A total slurry residence time is maintained in the reaction zone ranging from a finite value from about 0 to about 0.2 hour, and reaction effluent is continuously and directly contacted with a quenching fluid to substantially immediately reduce the temperature of the reaction effluent to below 425 C to substantially inhibit polymerization so that the yield of insoluble organic matter comprises less than 9 weight percent of said feed coal on a moisture-free basis. The reaction is performed under conditions of temperature, hydrogen pressure and residence time such that the quantity of distillate liquid boiling within the range C[sub 5]-454 C is an amount at least equal to that obtainable by performing the process under the same condition except for a longer total slurry residence time, e.g., 0.3 hour. Solvent boiling range liquid is separated from the reaction effluent and recycled as process solvent. The amount of solvent boiling range liquid is sufficient to provide at least 80 weight percent of that required to maintain the process in overall solvent balance. 6 figs.

Short residence time coal liquefaction process including catalytic hydrogenation

DOEpatents

Anderson, Raymond P.; Schmalzer, David K.; Wright, Charles H.

1982-05-18

Normally solid dissolved coal product and a distillate liquid product are produced by continuously passing a feed slurry comprising raw feed coal and a recycle solvent oil and/or slurry together with hydrogen to a preheating-reaction zone (26, alone, or 26 together with 42), the hydrogen pressure in the preheating-reaction zone being at least 1500 psig (105 kg/cm.sup.2), reacting the slurry in the preheating-reaction zone (26, or 26 with 42) at a temperature in the range of between about 455.degree. and about 500.degree. C. to dissolve the coal to form normally liquid coal and normally solid dissolved coal. A total slurry residence time is maintained in the reaction zone ranging from a finite value from about 0 to about 0.2 hour, and reaction effluent is continuously and directly contacted with a quenching fluid (40, 68) to substantially immediately reduce the temperature of the reaction effluent to below 425.degree. C. to substantially inhibit polymerization so that the yield of insoluble organic matter comprises less than 9 weight percent of said feed coal on a moisture-free basis. The reaction is performed under conditions of temperature, hydrogen pressure and residence time such that the quantity of distillate liquid boiling within the range C.sub.5 -454.degree. C. is an amount at least equal to that obtainable by performing the process under the same condition except for a longer total slurry residence time, e.g., 0.3 hour. Solvent boiling range liquid is separated from the reaction effluent (83) and recycled as process solvent (16). The amount of solvent boiling range liquid is sufficient to provide at least 80 weight percent of that required to maintain the process in overall solvent balance.

A novel kind of TSV slurry with guanidine hydrochloride

NASA Astrophysics Data System (ADS)

Jiao, Hong; Yuling, Liu; Baoguo, Zhang; Xinhuan, Niu; Liying, Han

2015-10-01

The effect of a novel alkaline TSV (through-silicon-via) slurry with guanidine hydrochloride (GH) on CMP (chemical mechanical polishing) was investigated. The novel alkaline TSV slurry was free of any inhibitors. During the polishing process, the guanidine hydrochloride serves as an effective surface-complexing agent for TSV CMP applications, the removal rate of barrier (Ti) can be chemically controlled through tuned selectivity with respect to the removal rate of copper and dielectric, which is helpful to modifying the dishing and gaining an excellent topography performance in TSV manufacturing. In this paper, we mainly studied the working mechanism of the components of slurry and the skillful application guanidine hydrochloride in the TSV slurry. Project supported by the Major National Science and Technology Special Projects (No. 2009ZX02308), the Fund Project of Hebei Provincial Department of Education, China (No. QN2014208), the Natural Science Foundation of Hebei Province, China (No. E2013202247), and Colleges and Universities Scientific research project of Hebei Province, China (No. Z2014088).

Self-cleaning feed distributing delivery device for glass melters

DOEpatents

Mensink, Daniel L.

1992-01-01

A self cleaning, plug resistant, adjustable parameter feed distributing and delivery apparatus for a glass melter comprising a housing with a passage therethrough for a glass slurry, a cold finger within the passage for creating a dispersion pattern of the slurry, a movable slotted tube for controlling the confluence of air propellant and slurry in the passage, and a plurality of ribs that extend through the slots in the slotted tube to urge the slurry forward if it becomes stuck or resists forward movement. Coolant passages in the housing and the cold finger maintain the slurry temperature below that of the melter plenum. The cold finger is axially movable to adjust the dispersion pattern to the desired consistency. Other design features of size can be applied for use in situations requiring different parameters of pattern, particle size, rate, and feed consistencies. The device utilizes air as both a propellant and a surface cleansing mechanism. Other fluids may be used as propellants where process compatibility requires.

YIELD STRESS REDUCTION OF DWPF MELTER FEED SLURRIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stone, M; Michael02 Smith, M

2006-12-28

The Defense Waste Processing Facility (DWPF) at the Savannah River Site vitrifies High Level Waste for repository internment. The process consists of three major steps: waste pretreatment, vitrification, and canister decontamination/sealing. The HLW consists of insoluble metal hydroxides (primarily iron, aluminum, magnesium, manganese, and uranium) and soluble sodium salts (carbonate, hydroxide, nitrite, nitrate, sulfate). The pretreatment process acidifies the sludge with nitric and formic acids, adds the glass formers as glass frit, then concentrates the resulting slurry to approximately 50 weight percent (wt%) total solids. This slurry is fed to the joule-heated melter where the remaining water is evaporated followedmore » by calcination of the solids and conversion to glass. The Savannah River National Laboratory (SRNL) is currently assisting DWPF efforts to increase throughput of the melter. As part of this effort, SRNL has investigated methods to increase the solids content of the melter feed to reduce the heat load required to complete the evaporation of water and allow more of the energy available to calcine and vitrify the waste. The process equipment in the facility is fixed and cannot process materials with high yield stresses, therefore increasing the solids content will require that the yield stress of the melter feed slurries be reduced. Changing the glass former added during pretreatment from an irregularly shaped glass frit to nearly spherical beads was evaluated. The evaluation required a systems approach which included evaluations of the effectiveness of beads in reducing the melter feed yield stress as well as evaluations of the processing impacts of changing the frit morphology. Processing impacts of beads include changing the settling rate of the glass former (which effects mixing and sampling of the melter feed slurry and the frit addition equipment) as well as impacts on the melt behavior due to decreased surface area of the beads versus frit. Beads were produced from the DWPF process frit by fire polishing. The frit was allowed to free fall through a flame, then quenched with a water spray. Approximately 90% of the frit was converted to beads by this process, as shown in Figure 1. Borosilicate beads of various diameters were also procured for initial testing.« less

Characterization of the March 2017 Tank 15 Waste Removal Slurry Sample (Combination of Slurry Samples HTF-15-17-28 and HTF-15-17-29)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reboul, S. H.; King, W. D.; Coleman, C. J.

2017-05-09

Two March 2017 Tank 15 slurry samples (HTF-15-17-28 and HTF-15-17-29) were collected during the second bulk waste removal campaign and submitted to SRNL for characterization. At SRNL, the two samples were combined and then characterized by a series of physical, elemental, radiological, and ionic analysis methods. Sludge settling as a function of time was also quantified. The characterization results reported in this document are consistent with expectations based upon waste type, process knowledge, comparisons between alternate analysis techniques, and comparisons with the characterization results obtained for the November 2016 Tank 15 slurry sample (the sample collected during the first bulkmore » waste removal campaign).« less

Multiphase Model of Semisolid Slurry Generation and Isothermal Holding During Cooling Slope Rheoprocessing of A356 Al Alloy

NASA Astrophysics Data System (ADS)

Das, Prosenjit; Samanta, Sudip K.; Mondal, Biswanath; Dutta, Pradip

2018-04-01

In the present paper, we present an experimentally validated 3D multiphase and multiscale solidification model to understand the transport processes involved during slurry generation with a cooling slope. In this process, superheated liquid alloy is poured at the top of the cooling slope and allowed to flow along the slope under the influence of gravity. As the melt flows down the slope, it progressively loses its superheat, starts solidifying at the melt/slope interface with formation of solid crystals, and eventually exits the slope as semisolid slurry. In the present simulation, the three phases considered are the parent melt as the primary phase, and the solid grains and air as secondary phases. The air phase forms a definable air/liquid melt interface as the free surface. After exiting the slope, the slurry fills an isothermal holding bath maintained at the slope exit temperature, which promotes further globularization of microstructure. The outcomes of the present model include prediction of volume fractions of the three different phases considered, grain evolution, grain growth, size, sphericity and distribution of solid grains, temperature field, velocity field, macrosegregation and microsegregation. In addition, the model is found to be capable of making predictions of morphological evolution of primary grains at the onset of isothermal coarsening. The results obtained from the present simulations are validated by performing quantitative image analysis of micrographs of the rapidly oil-quenched semisolid slurry samples, collected from strategic locations along the slope and from the isothermal slurry holding bath.

Sustainable Blended Cements-Influences of Packing Density on Cement Paste Chemical Efficiency.

PubMed

Knop, Yaniv; Peled, Alva

2018-04-18

This paper addresses the development of blended cements with reduced clinker amount by partial replacement of the clinker with more environmentally-friendly material (e.g., limestone powders). This development can lead to more sustainable cements with reduced greenhouse gas emission and energy consumption during their production. The reduced clicker content was based on improved particle packing density and surface area of the cement powder by using three different limestone particle diameters: smaller (7 µm, 3 µm) or larger (70 µm, 53 µm) than the clinker particles, or having a similar size (23 µm). The effects of the different limestone particle sizes on the chemical reactivity of the blended cement were studied by X-ray diffraction (XRD), thermogravimetry and differential thermogravimetry (TG/DTG), loss on ignition (LOI), isothermal calorimetry, and the water demand for reaching normal consistency. It was found that by blending the original cement with limestone, the hydration process and the reactivity of the limestone itself were increased by the increased surface area of the limestone particles. However, the carbonation reaction was decreased with the increased packing density of the blended cement with limestone, having various sizes.

In-situ activation of CuO/ZnO/Al.sub.2 O.sub.3 catalysts in the liquid phase

DOEpatents

Brown, Dennis M.; Hsiung, Thomas H.; Rao, Pradip; Roberts, George W.

1989-01-01

The present invention relates to a method of activation of a CuO/ZnO/Al.sub.2 O.sub.3 catalyst slurried in a chemically inert liquid. Successful activation of the catalyst requires the use of a process in which the temperature of the system at any time is not allowed to exceed a certain critical value, which is a function of the specific hydrogen uptake of the catalyst at that same time. This process is especially critical for activating highly concentrated catalyst slurries, typically 25 to 50 wt %. Activation of slurries of CuO/ZnO/Al.sub.2 O.sub.3 catalyst is useful in carrying out the liquid phase methanol or the liquid phase shift reactions.

Spatial and Temporal Changes in the Microbial Community in an Anaerobic Swine Waste Treatment Lagoon

USDA-ARS?s Scientific Manuscript database

Swine slurry is stored in pits beneath confinement buildings or in adjacent lagoons. This slurry is a valuable resource for crop fertilization and soil conditioning, but may also be a source of unpleasant odors. Microorganisms are crucial to all of the important processes that occur in anaerobic sto...

Influence of seasonal changes on the microbial community in an anaerobic swine waste treatment lagoon

USDA-ARS?s Scientific Manuscript database

Swine slurry is stored in pits beneath confinement buildings or in adjacent lagoons. This slurry is a valuable resource for crop fertilization and soil conditioning, but may also be a source of unpleasant odors. Microorganisms are crucial to all of the important processes that occur in anaerobic sto...

Changes in the phenolic acid content during commercial dry-grind processing of corn to ethanol and DDGS

USDA-ARS?s Scientific Manuscript database

Nine fractions (ground corn-1, cooked slurry-2, liquefied slurry-3, fermented mash-4, whole stillage-5, thin stillage-6, condensed distillers soluble (CDS)-7, distillers wet grains (DWG)-8, and distillers dried grains with solubles (DDGS)-9) were collected from three commercial dry-grind bioethanol ...

Integration of stripping of fines slurry in a coking and gasification process

DOEpatents

DeGeorge, Charles W.

1980-01-01

In an integrated fluid coking and gasification process wherein a stream of fluidized solids is passed from a fluidized bed coking zone to a second fluidized bed and wherein entrained solid fines are recovered by a wet scrubbing process and wherein the resulting solids-liquid slurry is stripped to remove acidic gases, the stripped vapors of the stripping zone are sent to the gas cleanup stage of the gasification product gas. The improved stripping integration is particularly useful in the combination coal liquefaction process, fluid coking of bottoms of the coal liquefaction zone and gasification of the product coke.

Modeling Remineralization of Desalinated Water by Micronized Calcite Dissolution.

PubMed

Hasson, David; Fine, Larissa; Sagiv, Abraham; Semiat, Raphael; Shemer, Hilla

2017-11-07

A widely used process for remineralization of desalinated water consists of dissolution of calcite particles by flow of acidified desalinated water through a bed packed with millimeter-size calcite particles. An alternative process consists of calcite dissolution by slurry flow of micron-size calcite particles with acidified desalinated water. The objective of this investigation is to provide theoretical models enabling design of remineralization by calcite slurry dissolution with carbonic and sulfuric acids. Extensive experimental results are presented displaying the effects of acid concentration, slurry feed concentration, and dissolution contact time. The experimental data are shown to be in agreement within less than 10% with theoretical predictions based on the simplifying assumption that the slurry consists of uniform particles represented by the surface mean diameter of the powder. Agreement between theory and experiment is improved by 1-8% by taking into account the powder size distribution. Apart from the practical value of this work in providing a hitherto lacking design tool for a novel technology. The paper has the merit of being among the very few publications providing experimental confirmation to the theory describing reaction kinetics in a segregated flow system.

A hybrid absorption–adsorption method to efficiently capture carbon

PubMed Central

Liu, Huang; Liu, Bei; Lin, Li-Chiang; Chen, Guangjin; Wu, Yuqing; Wang, Jin; Gao, Xueteng; Lv, Yining; Pan, Yong; Zhang, Xiaoxin; Zhang, Xianren; Yang, Lanying; Sun, Changyu; Smit, Berend; Wang, Wenchuan

2014-01-01

Removal of carbon dioxide is an essential step in many energy-related processes. Here we report a novel slurry concept that combines specific advantages of metal-organic frameworks, ion liquids, amines and membranes by suspending zeolitic imidazolate framework-8 in glycol-2-methylimidazole solution. We show that this approach may give a more efficient technology to capture carbon dioxide compared to conventional technologies. The carbon dioxide sorption capacity of our slurry reaches 1.25 mol l−1 at 1 bar and the selectivity of carbon dioxide/hydrogen, carbon dioxide/nitrogen and carbon dioxide/methane achieves 951, 394 and 144, respectively. We demonstrate that the slurry can efficiently remove carbon dioxide from gas mixtures at normal pressure/temperature through breakthrough experiments. Most importantly, the sorption enthalpy is only −29 kJ mol−1, indicating that significantly less energy is required for sorbent regeneration. In addition, from a technological point of view, unlike solid adsorbents slurries can flow and be pumped. This allows us to use a continuous separation process with heat integration. PMID:25296559

Estimation of Methane Emissions from Slurry Pits below Pig and Cattle Confinements

PubMed Central

Petersen, Søren O.; Olsen, Anne B.; Elsgaard, Lars; Triolo, Jin Mi; Sommer, Sven G.

2016-01-01

Quantifying in-house emissions of methane (CH4) from liquid manure (slurry) is difficult due to high background emissions from enteric processes, yet of great importance for correct estimation of CH4 emissions from manure management and effects of treatment technologies such as anaerobic digestion. In this study CH4 production rates were determined in 20 pig slurry and 11 cattle slurry samples collected beneath slatted floors on six representative farms; rates were determined within 24 h at temperatures close to the temperature in slurry pits at the time of collection. Methane production rates in pig and cattle slurry differed significantly at 0.030 and 0.011 kg CH4 kg-1 VS (volatile solids). Current estimates of CH4 emissions from pig and cattle manure management correspond to 0.032 and 0.015 kg CH4 kg-1, respectively, indicating that slurry pits under animal confinements are a significant source. Fractions of degradable volatile solids (VSd, kg kg-1 VS) were estimated using an aerobic biodegradability assay and total organic C analyses. The VSd in pig and cattle slurry averaged 0.51 and 0.33 kg kg-1 VS, and it was estimated that on average 43 and 28% of VSd in fresh excreta from pigs and cattle, respectively, had been lost at the time of sampling. An empirical model of CH4 emissions from slurry was reparameterised based on experimental results. A sensitivity analysis indicated that predicted CH4 emissions were highly sensitive to uncertainties in the value of lnA of the Arrhenius equation, but much less sensitive to uncertainties in VSd or slurry temperature. A model application indicated that losses of carbon in VS as CO2 may be much greater than losses as CH4. Implications of these results for the correct estimation of CH4 emissions from manure management, and for the mitigation potential of treatments such as anaerobic digestion, are discussed. PMID:27529692

Controlled short residence time coal liquefaction process

DOEpatents

Anderson, Raymond P.; Schmalzer, David K.; Wright, Charles H.

1982-05-04

Normally solid dissolved coal product and a distillate liquid product are produced by continuously passing a feed slurry comprising raw feed coal and a recycle solvent oil and/or slurry together with hydrogen to a preheating-reaction zone (26, alone, or 26 together with 42), the hydrogen pressure in the preheating-reaction zone being at least 1500 psig (105 kg/cm.sup.2), reacting the slurry in the preheating-reaction zone (26, or 26 with 42) at a temperature in the range of between about 455.degree. and about 500.degree. C. to dissolve the coal to form normally liquid coal and normally solid dissolved coal. A total slurry residence time is maintained in the reaction zone ranging from a finite value from about 0 to about 0.2 hour, and reaction effluent is continuously and directly contacted with a quenching fluid (40, 68) to substantially immediately reduce the temperature of the reaction effluent to below 425.degree. C. to substantially inhibit polymerization so that the yield of insoluble organic matter comprises less than 9 weight percent of said feed coal on a moisture-free basis. The reaction is performed under conditions of temperature, hydrogen pressure and residence time such that the quantity of distillate liquid boiling within the range C.sub.5 -455.degree. C. is an amount at least equal to that obtainable by performing the process under the same conditions except for a longer total slurry residence time, e.g., 0.3 hour. Solvent boiling range liquid is separated from the reaction effluent and recycled as process solvent.

Effect of the Process Parameters on the Formability, Microstructure, and Mechanical Properties of Thin Plates Fabricated by Rheology Forging Process with Electromagnetic Stirring Method

NASA Astrophysics Data System (ADS)

Jin, Chul Kyu; Jang, Chang Hyun; Kang, Chung Gil

2014-01-01

A thin plate (150 × 150 × 1.2 mm) with embedded corrugation is fabricated using the rheoforming method. Semisolid slurry is created using the electromagnetic stirring (EMS) system, and the thin plate is made with the forging die at the 200-ton hydraulic press. The cross sections and microstructures of the slurry with and without stirring are examined. To investigate the effect of the process parameters on the formability, microstructure, and mechanical properties of thin plate the slurry is subjected to 16 types of condition for the forging experiment. The 16 types included the following conditions: Whether the EMS is applied or not, three fractions of the solid phase at 35, 45 and 55 pct; two compression velocities at 30 and 300 mm s-1; and four different compression pressures—100, 150, 200 and 250 MPa. The thin plate's formability is enhanced at higher punch velocity for compressing the slurry, and fine solid particles are uniformly distributed, which in turn, enhances the plate's mechanical properties. The pressure between 150 and 200 MPa is an appropriate condition to form thin plates. A thin plate without defects can be created when the slurry at 35 pct of the solid fraction (f s) was applied at the compression velocity of 300 mm s-1 and 150 MPa of pressure. The surface state of thin plate is excellent with 220 MPa of tensile strength and 13.5 pct of elongation. The primary particles are fine over the entire plate, and there are no liquid segregation-related defects.

Reduction of soil pollution by usingwaste of the limestone in the cement industry

NASA Astrophysics Data System (ADS)

Muñoz, M. Cecilia Soto; Robles Castillo, Marcelo; Blanco Fernandez, David; Diaz Gonzalez, Marcos; Naranjo Lamilla, Pedro; Moore Undurraga, Fernando; Pardo Fabregat, Francisco; Vidal, Manuel Miguel Jordan; Bech, Jaume; Roca, Nuria

2016-04-01

In the cement manufacturing process (wet) a residue is generated in the flotation process. This builds up causing contamination of soil, groundwater and agricultural land unusable type. In this study to reduce soil and water pollution 10% of the dose of cement was replaced by waste of origin limestone. Concretes were produced with 3 doses of cement and mechanical strengths of each type of concrete to 7, 28 and 90 days were determined. the results indicate that the characteristics of calcareous residue can replace up to 10% of the dose of cement without significant decreases in strength occurs. It is noted that use of the residue reduces the initial resistance, so that the dose of cement should not be less than 200 kg of cement per m3. The results allow recommends the use of limestone waste since it has been observed decrease in soil and water contamination without prejudice construction material Keywords: Soil contamination; Limestone residue; Adding concrete

Characterization of Diarrheagenic Escherichia coli Isolated in Organic Waste Products (Cattle Fecal Matter, Manure and, Slurry) from Cattle’s Markets in Ouagadougou, Burkina Faso

PubMed Central

Bako, Evariste; Kagambèga, Assèta; Traore, Kuan Abdoulaye; Bagre, Touwendsida Serge; Ibrahim, Hadiza Bawa; Bouda, Soutongnooma Caroline; Bonkoungou, Isidore Juste Ouindgueta; Kaboré, Saidou; Zongo, Cheikna; Traore, Alfred Sababenejo; Barro, Nicolas

2017-01-01

Cattle farming can promote diarrheal disease transmission through waste, effluents or cattle fecal matter. The study aims to characterize the diarrheagenic Escherichia coli (DEC) isolated from cattle feces, manure in the composting process and slurry, collected from four cattle markets in Ouagadougou. A total of 585 samples (340 cattle feces, 200 slurries and 45 manures in the composting process) were collected from the four cattle markets between May 2015 and May 2016. A multiplex Polymerase Chain Reaction (PCR), namely 16-plex PCR, was used to screen simultaneously the virulence genes specific for shiga toxin-producing E. coli (STEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC) and enteroaggregative E. coli (EAEC). DEC was detected in 10.76% of samples. ETEC was the most prevalent (9.91%). STEC and EAEC have been observed with the same rate (0.51%). ETEC were detected in 12.64% of cattle feces, in 6.66% of manure in the composting process and in 5% of slurry. STEC were detected in 0.58% of cattle feces and in 2.22% of manure in the composting process. EAEC was detected only in 1% of slurry and in 2.22% of manure in the composting process. ETEC strains were identified based on estIa gene and/or estIb gene and/or elt gene amplification. Of the 58 ETEC, 10.34% contained astA, 17.24% contained elt, 3.44% contained estIa and 79.31% contained estIb. The two positive EAEC strains contained only the aggR gene, and the third was positive only for the pic gene. The results show that effluent from cattle markets could contribute to the spreading of DEC in the environment in Burkina Faso. PMID:28937656

Diversity of thermophilic populations during thermophilic aerobic digestion of potato peel slurry.

PubMed

Ugwuanyi, J O; Harvey, L M; McNeil, B

2008-01-01

To study the diversity of thermophiles during thermophilic aerobic digestion (TAD) of agro-food waste slurries under conditions similar to full-scale processes. Population diversity and development in TAD were studied by standard microbiological techniques and the processes monitored by standard fermentation procedures. Facultative thermophiles were identified as Bacillus coagulans and B. licheniformis, while obligate thermophiles were identified as B. stearothermophilus. They developed rapidly to peaks of 10(7) to 10(8) in

Microorganism mediated liquid fuels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Troiano, Richard

Herein disclosed is a method for producing liquid hydrocarbon product, the method comprising disintegrating a hydrocarbon source; pretreating the disintegrated hydrocarbon source; solubilizing the disintegrated hydrocarbon source to form a slurry comprising a reactant molecule of the hydrocarbon source; admixing a biochemical liquor into the slurry, wherein the biochemical liquor comprises at least one conversion enzyme configured to facilitate bond selective photo-fragmentation of said reactant molecule of the hydrocarbon source, to form liquid hydrocarbons via enzyme assisted bond selective photo-fragmentation, wherein said conversion enzyme comprises reactive sites configured to restrict said reactant molecule such that photo-fragmentation favorably targets a preselectedmore » internal bond of said reactant molecule; separating the liquid hydrocarbons from the slurry, wherein contaminants remain in the slurry; and enriching the liquid hydrocarbons to form a liquid hydrocarbon product. Various aspects of such method/process are also discussed.« less

Wet separation processes as method to separate limestone and oil shale

NASA Astrophysics Data System (ADS)

Nurme, Martin; Karu, Veiko

2015-04-01

Biggest oil shale industry is located in Estonia. Oil shale usage is mainly for electricity generation, shale oil generation and cement production. All these processes need certain quality oil shale. Oil shale seam have interlayer limestone layers. To use oil shale in production, it is needed to separate oil shale and limestone. A key challenge is find separation process when we can get the best quality for all product types. In oil shale separation typically has been used heavy media separation process. There are tested also different types of separation processes before: wet separation, pneumatic separation. Now oil shale industry moves more to oil production and this needs innovation methods for separation to ensure fuel quality and the changes in quality. The pilot unit test with Allmineral ALLJIG have pointed out that the suitable new innovation way for oil shale separation can be wet separation with gravity, where material by pulsating water forming layers of grains according to their density and subsequently separates the heavy material (limestone) from the stratified material (oil shale)bed. Main aim of this research is to find the suitable separation process for oil shale, that the products have highest quality. The expected results can be used also for developing separation processes for phosphorite rock or all others, where traditional separation processes doesn't work property. This research is part of the study Sustainable and environmentally acceptable Oil shale mining No. 3.2.0501.11-0025 http://mi.ttu.ee/etp and the project B36 Extraction and processing of rock with selective methods - http://mi.ttu.ee/separation; http://mi.ttu.ee/miningwaste/

Coal Research

NASA Technical Reports Server (NTRS)

1986-01-01

Coal slurries are "clean" pulverized coal mixed with oil or water. Significant fuel savings can be realized when using coal slurries. Advanced Fuels Technology (AFT) utilized a COSMIC program, (Calculation of Complex Chemical Equilibrium Compositions), which provides specific capabilities for determining combustion products. The company has developed a cleaning process that removes much of the mineral sulphur and ash from the coals.

Apparatus for converting biomass to a pumpable slurry

DOEpatents

Ergun, Sabri; Schaleger, Larry L.; Wrathall, James A.; Yaghoubzadeh, Nasser

1986-01-01

An apparatus used in the pretreatment of wood chips in a process for converting biomass to a liquid hydrocarbonaceous fuel. The apparatus functions to break down the wood chips to a size distribution that can be readily handled in a slurry form. Low maintenance operation is obtained by hydrolyzing the chips in a pressure vessel having no moving parts.

DWPF DECON FRIT: SUMP AND SLURRY SOLIDS ANALYSIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crawford, C.; Peeler, D.; Click, D.

The Savannah River National Laboratory (SRNL) has been requested to perform analyses on samples of the Defense Waste Processing Facility (DWPF) decon frit slurry (i.e., supernate samples and sump solid samples). Four 1-L liquid slurry samples were provided to SRNL by Savannah River Remediation (SRR) from the 'front-end' decon activities. Additionally, two 1-L sump solids samples were provided to SRNL for compositional and physical analysis. In this report, the physical and chemical characterization results of the slurry solids and sump solids are reported. Crawford et al. (2010) provide the results of the supernate analysis. The results of the sump solidsmore » are reported on a mass basis given the samples were essentially dry upon receipt. The results of the slurry solids were converted to a volume basis given approximately 2.4 grams of slurry solids were obtained from the {approx}4 liters of liquid slurry sample. Although there were slight differences in the analytical results between the sump solids and slurry solids the following general summary statements can be made. Slight differences in the results are also captured for specific analysis. (1) Physical characterization - (a) SEM/EDS analysis suggested that the samples were enriched in Li and Si (B and Na not detectable using the current EDS system) which is consistent with two of the four principle oxides of Frit 418 (B{sub 2}O{sub 3}, Na{sub 2}O, Li{sub 2}O and SiO{sub 2}). (b) SEM/EDS analysis also identified impurities which were elementally consistent with stainless steel (i.e., Fe, Ni, Cr contamination). (c) XRD results indicated that the sump solids samples were amorphous which is consistent with XRD results expected for a Frit 418 based sample. (d) For the sump solids, SEM/EDS analysis indicated that the particle size of the sump solids were consistent with that of an as received Frit 418 sample from a current DWPF vendor. (e) For the slurry solids, SEM/EDS analysis indicated that the particle size range of the slurry solids was much broader than compared to the sump solids. More specifically, there were significantly more fines in the slurry solids as compared to the sump solids. (f) PSD results indicated that > 99% of both the sump and slurry solids were less than 350 microns. The PSD results also supported SEM/EDS analysis that there were significantly more fines in the slurry solids as compared to the sump solids. (2) Weight Percent Solids - Based on the measured supernate density and mass of insoluble solids (2.388 grams) filtered from the four liters of liquid slurry samples, the weight percent insoluble solids was estimated to be 0.060 wt%. This level of insoluble solids is higher than the ETP WAC limit of 100 mg/L, or 0.01 wt% which suggests a separation technology of some type would be required. (3) Chemical Analysis - (a) Elemental results from ICP-ES analysis indicated that the sump solids and slurry were very consistent with the nominal composition of Frit 418. There were other elements identified by ICP analysis which were either consistent with the presence of stainless steel (as identified by SEM/EDS analysis) or impurities that have been observed in 'as received' Frit 418 from the vendor. (b) IC anion analysis of the sump solids and slurry solids indicated all of the species were less than detection limits. (c) Radionuclide analysis of the sump solids also indicated that most of the analytes were either at or below the detection limits. (d) Organic analysis of the sump solids and slurry solids indicated all of the species were less than detection limits. It should be noted that the results of this study may not be representative of future decon frit solutions or sump/slurry solids samples. Therefore, future DWPF decisions regarding the possible disposal pathways for either the aqueous or solid portions of the Decon Frit system need to factor in the potential differences. More specifically, introduction of a different frit or changes to other DWPF flowsheet unit operations (e.g., different sludge batch or coupling with other process streams) may impact not only the results but also the conclusions regarding acceptability with respect to the ETF WAC limits or other alternative disposal options.« less

Process and apparatus for coal hydrogenation

DOEpatents

Ruether, John A.

1988-01-01

In a coal liquefaction process an aqueous slurry of coal is prepared containing a dissolved liquefaction catalyst. A small quantity of oil is added to the slurry and then coal-oil agglomerates are prepared by agitation of the slurry at atmospheric pressure. The resulting mixture of agglomerates, excess water, dissolved catalyst, and unagglomerated solids is pumped to reaction pressure and then passed through a drainage device where all but a small amount of surface water is removed from the agglomerates. Sufficient catalyst for the reaction is contained in surface water remaining on the agglomerates. The agglomerates fall into the liquefaction reactor countercurrently to a stream of hot gas which is utilized to dry and preheat the agglomerates as well as deposit catalyst on the agglomerates before they enter the reactor where they are converted to primarily liquid products under hydrogen pressure.

Retention and transport of graphene oxide in water-saturated limestone media.

PubMed

Dong, Shunan; Sun, Yuanyuan; Gao, Bin; Shi, Xiaoqing; Xu, Hongxia; Wu, Jianfeng; Wu, Jichun

2017-08-01

In this work, column experiments were conducted to investigate the transport characteristics of graphene oxide (GO) nanoparticles in limestone media under various electrolytes, solution pH, and humic acid (HA) concentration conditions. In the limestone media, GO exhibited relatively low mobility with the mass recovery rate lower than 65.2%, even when solution ionic strength was low. The presence of HA enhanced its mobility. In addition, the presence of S 2- , a divalent anion, also promoted GO transport in limestone media compared to Cl - under similar ionic strength conditions through neutralizing more positive charge and thus diminishing the cation bridging. Solution pH showed slight effect on the transport of GO in limestone with the mass recovery range from 40.3% to 51.7%. Over all, decreases in solution pH, HA concentration and increases in solution ionic strength reduced the mobility of GO in the limestone media under the tested conditions. These results indicated both environmental conditions and media characteristics played important roles in controlling GO fate and transport in porous media. The one-site kinetic deposition model was applied to describe the interactions between the GO and limestone media and model simulations fitted the observed experimental data very well. As limestone is an important component of aquiferous media in subsurface, findings from this study elucidated the key factors and processes controlling the fate of GO particles in limestone media, which can inform the prediction and assessment of the risks of GO in groundwater environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Making soy sauce from defatted soybean meal without the mejus process by submerged cultivation using thermophilic bacteria.

PubMed

Hur, Jeong Min; Park, Doo Hyun

2015-08-01

The diversity of thermophilic bacteria was not significantly altered while growing in a defatted soybean meal (DFSM) slurry at 60 °C for 10, 20, and 30 days. Five species of thermophilic bacteria, which belong to the genera Aeribacillus (temperature gradient gel electrophoresis [TGGE] band no. 1), Saccharococcus (TGGE band no. 2), Geobacillus (TGGE band no. 3), Bacillus (TGGE band no. 4), and Anoxybacillus (TGGE band no. 5), were detected in the fermenting DFSM slurry. The cell-free culture fluid obtained from the fermenting DFSM slurry on day 14 hydrolyzed starch and soy protein at 60 °C but not at 30 °C. Soy sauce (test soy sauce) was prepared from the fermented DFSM slurry after a 30 day cultivation at 60 °C and a 60 day ripening at 45 °C. Free amino acid (AA) and organic acid contents in the soy sauce increased in proportion to the fermentation period, whereas ammonium decreased proportionally. Mg and Ca contained in the soy sauce decreased proportionally during fermentation and were lower than those in the non-fermented DFSM extract (control). Spectral absorbance of soy sauce prepared from the fermented DFSM slurry was maximal at 430 nm and increased slightly in proportion to the fermentation period. The aroma and flavor of the test soy sauce were significantly different from those of traditional Korean soy sauce. Conclusively, soy sauce may be prepared directly from the fermented DFSM slurry without meju-preparing process and fermentation period may be a factor for control of soy sauce quality.

Effect of environmental conditions on the decay of stone in archaeological site of Volubilis - Morocco

NASA Astrophysics Data System (ADS)

Aalil, Issam; Chaaba, Ali; Cherkaoui, Khalid; Brunetaud, Xavier; Beck, Kevin; Al-Mukhtar, Muzahim

2015-04-01

Volubilis is the most excavated and the best preserved archaeological site of Morocco. Located about thirty kilometres north of Meknes, it was a Mauritanian capital founded in the 3rd century B.C., and became an important outpost of the Roman Empire. Volubilis monuments are constructed with five regional lithotypes of limestone. A grey massive limestone and beige-yellowish calcarenite limestone are the two most largely used on Volubilis site, representing respectively about 30% and 60 % of the total volume of building stones. Field observations showed that the calcarenite limestone is more decayed than the massive limestone and is mainly affected by scaling, alveolization and sanding. This work aims to estimate the role of environmental conditions on the decay of the calcarenite stone through the effect of thermal stresses and freezing-thawing action. Air temperature data of Meknes station is analysed. Furthermore, mineralogical composition of the calcarenite limestone and its intrinsic properties required for stress calculation are determined. The results of this study show that the calcarenite limestone is a quite soft carbonate stone, contains about 71 % of calcite, 18 % of quartz and others accessory minerals. Besides, there is no risk of damage due to freezing-thawing processes. Nonetheless, thermal stresses may have an important role in the decay of calcarenite stones of the Volubilis site.

Carbonate Minerals with Magnesium in Triassic Terebratula Limestone in the Term of Limestone with Magnesium Application as a Sorbent in Desulfurization of Flue Gases

NASA Astrophysics Data System (ADS)

Stanienda-Pilecki, Katarzyna

2017-09-01

This article presents the results of studies of Triassic (Muschelkalk) carbonate rock samples of the Terebratula Beds taken from the area of the Polish part of the Germanic Basin. It is the area of Opole Silesia. The rocks were studied in the term of possibility of limestone with magnesium application in desulfurization of flue gases executed in power plants. Characteristic features of especially carbonate phases including magnesium-low-Mg calcite, high-Mg calcite, dolomite and huntite were presented in the article. They were studied to show that the presence of carbonate phases with magnesium, especially high-Mg calcite makes the desulfurization process more effective. Selected rock samples were examined using a microscope with polarized, transmitted light, X-ray diffraction, microprobe measurements and FTIR spectroscopy. The results of studies show a domination of low magnesium calcite in the limestones of the Terebratula Beds. In some samples dolomite and lower amounts of high-Mg calcite occurred. Moreover, huntite was identified. The studies were very important, because carbonate phases like high-Mg calcite and huntite which occurred in rocks of the Triassic Terebratula Beds were not investigated in details by other scientists but they presence in limestone sorbent could influence the effectiveness of desulfurization process.

Identification of Inhibitors in Lignocellulosic Slurries and Determination of Their Effect on Hydrocarbon-Producing Microorganisms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Shihui; Franden, Mary A; Yang, Qing

The aim of this work was to identify inhibitors in pretreated lignocellulosic slurries, evaluate high-throughput screening strategies, and investigate the impact of inhibitors on potential hydrocarbon-producing microorganisms. Compounds present in slurries that could inhibit microbial growth were identified through a detailed analysis of saccharified slurries by applying a combination of approaches of high-performance liquid chromatography, GC-MS, LC-DAD-MS, and ICP-MS. Several high-throughput assays were then evaluated to generate toxicity profiles. Our results demonstrated that Bioscreen C was useful for analyzing bacterial toxicity but not for yeast. AlamarBlue reduction assay can be a useful high-throughput assay for both bacterial and yeast strainsmore » as long as medium components do not interfere with fluorescence measurements. In addition, this work identified two major inhibitors (furfural and ammonium acetate) for three potential hydrocarbon-producing bacterial species that include Escherichia coli, Cupriavidus necator, and Rhodococcus opacus PD630, which are also the primary inhibitors for ethanologens. Here, this study was strived to establish a pipeline to quantify inhibitory compounds in biomass slurries and high-throughput approaches to investigate the effect of inhibitors on microbial biocatalysts, which can be applied for various biomass slurries or hydrolyzates generated through different pretreatment and enzymatic hydrolysis processes or different microbial candidates.« less

Identification of Inhibitors in Lignocellulosic Slurries and Determination of Their Effect on Hydrocarbon-Producing Microorganisms

DOE PAGES

Yang, Shihui; Franden, Mary A; Yang, Qing; ...

2018-04-04

The aim of this work was to identify inhibitors in pretreated lignocellulosic slurries, evaluate high-throughput screening strategies, and investigate the impact of inhibitors on potential hydrocarbon-producing microorganisms. Compounds present in slurries that could inhibit microbial growth were identified through a detailed analysis of saccharified slurries by applying a combination of approaches of high-performance liquid chromatography, GC-MS, LC-DAD-MS, and ICP-MS. Several high-throughput assays were then evaluated to generate toxicity profiles. Our results demonstrated that Bioscreen C was useful for analyzing bacterial toxicity but not for yeast. AlamarBlue reduction assay can be a useful high-throughput assay for both bacterial and yeast strainsmore » as long as medium components do not interfere with fluorescence measurements. In addition, this work identified two major inhibitors (furfural and ammonium acetate) for three potential hydrocarbon-producing bacterial species that include Escherichia coli, Cupriavidus necator, and Rhodococcus opacus PD630, which are also the primary inhibitors for ethanologens. Here, this study was strived to establish a pipeline to quantify inhibitory compounds in biomass slurries and high-throughput approaches to investigate the effect of inhibitors on microbial biocatalysts, which can be applied for various biomass slurries or hydrolyzates generated through different pretreatment and enzymatic hydrolysis processes or different microbial candidates.« less

Nisin: a possible alternative or adjunct to nitrite in the preservation of meats.

PubMed Central

Rayman, M K; Aris, B; Hurst, A

1981-01-01

Nisin at 75 ppm (75 microgram/g) was superior to 150 ppm of nitrite in inhibiting outgrowth of Clostridium sporogenes PA3679 spores in meat slurries, which had been heated to simulate the process used for cooked ham. The inhibitory activity of nisin decreased as the spore load or pH of the slurries increased. Unlike nitrite, inhibition by nisin was unaffected by high levels of iron either as a constituent of meats or when added as an iron salt. In slurries treated with 75 ppm of nisin, refrigerated storage for 56 days resulted in depletion of nisin to a level low enough to allow outgrowth within 3 to 10 days if the slurries were subsequently abused at 35 degrees C. In contrast, a combination of 40 ppm of nitrite and either 75 or 100 ppm of nisin almost completely inhibited outgrowth in these slurries. The nisin-nitrite combination appeared to have a synergistic effect, and the low concentration of nitrite was sufficient to preserve the color in meats similar to that of products cured with 150 ppm of nitrite. PMID:7195188

Anaerobic aquifer transformations of 2,4-Dinitrophenol under different terminal electron accepting conditions

USGS Publications Warehouse

Krumholz, L.R.; Suflita, J.M.

1997-01-01

We evaluated the susceptibility of 2,4-dinitrophenol (2,4-DNP) and 2,4-diaminophenol to anaerobic biodegradation in aquifer slurries. Aquifer microorganisms depleted 2,4-DNP at rates of 25, 9 and 0.4 μM/day under methanogenic, sulfate-reducing and nitrate-reducing conditions, respectively. Rates of abiotic, 2,4-DNP loss in autoclaved control incubations were 7.2, 6.2 and 0.95 μM/day respectively. Abiotic, 2,4-DNP reduction was especially important as the first step in its transformation. 2-Amino-4-nitrophenol was produced by this process, but this compound was further metabolized in methanogenic and sulfate-reducing aquifer slurries. This partially reduced compound persisted in autoclaved controls and in the nitrate-reducing aquifer slurries. Aquifer slurries incubated with either 2,4-DNP or 2,4-diaminophenol produced methane when incubated with no other electron acceptor suggesting that mineralization had occurred under these conditions. In parallel experiments, aquifer slurries amended with 2,6-dinitrophenol or picric acid did not produce methane at levels above the substrate unamended controls.

Concentration and Velocity Measurements of Both Phases in Liquid-Solid Slurries

NASA Astrophysics Data System (ADS)

Altobelli, Stephen; Hill, Kimberly; Caprihan, Arvind

2007-03-01

Natural and industrial slurry flows abound. They are difficult to calculate and to measure. We demonstrate a simple technique for studying steady slurries. We previously used time-of-flight techniques to study pressure driven slurry flow in pipes. Only the continuous phase velocity and concentration fields were measured. The discrete phase concentration was inferred. In slurries composed of spherical, oil-filled pills and poly-methyl-siloxane oils, we were able to use inversion nulling to measure the concentration and velocity fields of both phases. Pills are available in 1-5mm diameter and silicone oils are available in a wide range of viscosities, so a range of flows can be studied. We demonstrated the technique in horizontal, rotating cylinder flows. We combined two tried and true methods to do these experiments. The first used the difference in T1 to select between phases. The second used gradient waveforms with controlled first moments to produce velocity dependent phase shifts. One novel processing method was developed that allows us to use static continuous phase measurements to reference both the continuous and discrete phase velocity images. ?

Emplacement and dewatering of the world's largest exposed sand injectite complex

NASA Astrophysics Data System (ADS)

Sherry, Timothy J.; Rowe, Christie D.; Kirkpatrick, James D.; Brodsky, Emily E.

2012-08-01

Sandstone injectites form by up or down-section flow of a mobilized sand slurry through fractures in overlying rock. They act as reservoirs and high-permeability conduits through lower permeability rock in hydrocarbon systems. The Yellow Bank Creek Complex, Santa Cruz County, California is the largest known exposure of a sandstone injectite in the world. The complex contains granular textures that record processes of sand slurry flow, multiple pore fluids, and dewatering after emplacement. The injection was initially mobilized from a source containing both water and hydrocarbons. The water-sand slurry reached emplacement depth first, due to lower fluid viscosity. As the sand slurry emplaced, the transition from slurry flow to pore water percolation occurred. This transition resulted in preferred flow channels ˜6 mm wide in which sand grains were weakly aligned (laminae). The hydrocarbon-sand slurry intruded the dewatering sands and locally deformed the laminae. Compaction of the injectite deposit and pore fluid escape caused spaced compaction bands and dewatering pipes which created convolutions of the laminae. The hydrocarbon-rich sand slurry is preserved today as dolomite-cemented sand with oil inclusions. The laminae in this injectite are easily detected due to preferential iron oxide-cementation of the well-aligned sand laminae, and lack of cement in the alternating laminae. Subtle textures like these may develop during sand flow and be present but difficult to detect in other settings. They may explain permeability anisotropy in other sand deposits.

Effect of acidity and elevated PCO2 on acid. Neutralization within pulsed limestone bed reactors receiving coal mine drainage

USGS Publications Warehouse

Watten, B.J.; Sibrell, P.L.; Schwartz, M.F.

2004-01-01

Limestone has potential for reducing reagent costs and sludge volume associated with the treatment of acid mine drainage (AMD), but its use has been restricted by slow dissolution rates and sensitivity to scale forming reactions that retard transport of H+ at the solid-liquid interface. We evaluated a pulsed limestone bed (PLB) remediation process designed to circumvent these problems through use of intermittently fluidized beds of granular limestone and elevated carbon dioxide pressure. PLB limestone dissolution (LD, mg/L), and effluent alkalinity (Alk, mg/L) were correlated with reactor pressure (PCO2, kPa), influent acidity (Acy, mg/L) and reactor bed height (H, cm) using a prototype capable of processing 10 L/min. The PLB process effectively neutralized sulfuric acid acidity over the range of 6-1033 mg/L (as CaCO3) while generating high concentrations of alkalinity (36-1086 mg/L) despite a hydraulic residence time of just 4.2-5.0 min. Alk and LD (mg/L CaCO3) rose with increases in influent acidity and PCO2 (p < 0.001) according to the models: Alk = 58 + 38.4 (PCO2)0.5 + 0.080 (Acy) - 0.0059(PCO2) 0.5 (Acy); LD = 55 + 38.3 (PCO2)0.5 + 1.08 (Acy) - 0.0059 (PCO2)0.5 (Acy). Alkalinity decreased at an increasing rate with reductions in H over the range of 27.3-77.5 cm (p < 0.001). Carbon dioxide requirements (Q(avg)CO2, L/min) increased with PCO2 (p < 0.001) following the model Q(avg)CO2 = 0.858 (PCO2)0.620, resulting in a greater degree of pH buffering (depression) within the reactors, a rise in limestone solubility and an increase in limestone dissolution related to carbonic acid attack. Corresponding elevated concentrations of effluent alkalinity allow for sidestream treatment with blending. Numerical modeling demonstrated that carbon dioxide requirements are reduced as influent acidity rises and when carbon dioxide is recovered from system effluent and recycled. Field trials demonstrated that the PLB process is capable of raising the pH of AMD above that required for hydrolysis and precipitation of Fe3+ and Al 3+ but not Fe2+ and Mn2+.

Effects of imposed salinity gradients on dissimilatory arsenate reduction, sulfate reduction, and other microbial processes in sediments from two California soda lakes

USGS Publications Warehouse

Kulp, T.R.; Han, S.; Saltikov, C.W.; Lanoil, B.D.; Zargar, K.; Oremland, R.S.

2007-01-01

Salinity effects on microbial community structure and on potential rates of arsenate reduction, arsenite oxidation, sulfate reduction, denitrification, and methanogenesis were examined in sediment slurries from two California soda lakes. We conducted experiments with Mono Lake and Searles Lake sediments over a wide range of salt concentrations (25 to 346 g liter-1). With the exception of sulfate reduction, rates of all processes demonstrated an inverse relationship to total salinity. However, each of these processes persisted at low but detectable rates at salt saturation. Denaturing gradient gel electrophoresis analysis of partial 16S rRNA genes amplified from As(V) reduction slurries revealed that distinct microbial populations grew at low (25 to 50 g liter-1), intermediate (100 to 200 g liter-1), and high (>300 g liter-1) salinity. At intermediate and high salinities, a close relative of a cultivated As-respiring halophile was present. These results suggest that organisms adapted to more dilute conditions can remain viable at high salinity and rapidly repopulate the lake during periods of rising lake level. In contrast to As reduction, sulfate reduction in Mono Lake slurries was undetectable at salt saturation. Furthermore, sulfate reduction was excluded from Searles Lake sediments at any salinity despite the presence of abundant sulfate. Sulfate reduction occurred in Searles Lake sediment slurries only following inoculation with Mono Lake sediment, indicating the absence of sulfate-reducing flora. Experiments with borate-amended Mono Lake slurries suggest that the notably high (0.46 molal) concentration of borate in the Searles Lake brine was responsible for the exclusion of sulfate reducers from that ecosystem. Copyright ?? 2007, American Society for Microbiology. All Rights Reserved.

Evaluation of different types of anaerobic seed sludge for the high rate anaerobic digestion of pig slurry in UASB reactors.

PubMed

Rico, Carlos; Montes, Jesús A; Rico, José Luis

2017-08-01

Three different types of anaerobic sludge (granular, thickened digestate and anaerobic sewage) were evaluated as seed inoculum sources for the high rate anaerobic digestion of pig slurry in UASB reactors. Granular sludge performance was optimal, allowing a high efficiency process yielding a volumetric methane production rate of 4.1LCH 4 L -1 d -1 at 1.5days HRT (0.248LCH 4 g -1 COD) at an organic loading rate of 16.4gCODL -1 d -1 . The thickened digestate sludge experimented flotation problems, thus resulting inappropriate for the UASB process. The anaerobic sewage sludge reactor experimented biomass wash-out, but allowed high process efficiency operation at 3days HRT, yielding a volumetric methane production rate of 1.7LCH 4 L -1 d -1 (0.236LCH 4 g -1 COD) at an organic loading rate of 7.2gCODL -1 d -1 . To guarantee the success of the UASB process, the settleable solids of the slurry must be previously removed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Groundwater monitoring of an open-pit limestone quarry: groundwater characteristics, evolution and their connections to rock slopes.

PubMed

Eang, Khy Eam; Igarashi, Toshifumi; Fujinaga, Ryota; Kondo, Megumi; Tabelin, Carlito Baltazar

2018-03-06

Groundwater flow and its geochemical evolution in mines are important not only in the study of contaminant migration but also in the effective planning of excavation. The effects of groundwater on the stability of rock slopes and other mine constructions especially in limestone quarries are crucial because calcite, the major mineral component of limestone, is moderately soluble in water. In this study, evolution of groundwater in a limestone quarry located in Chichibu city was monitored to understand the geochemical processes occurring within the rock strata of the quarry and changes in the chemistry of groundwater, which suggests zones of deformations that may affect the stability of rock slopes. There are three distinct geological formations in the quarry: limestone layer, interbedded layer of limestone and slaty greenstone, and slaty greenstone layer as basement rock. Although the hydrochemical facies of all groundwater samples were Ca-HCO 3 type water, changes in the geochemical properties of groundwater from the three geological formations were observed. In particular, significant changes in the chemical properties of several groundwater samples along the interbedded layer were observed, which could be attributed to the mixing of groundwater from the limestone and slaty greenstone layers. On the rainy day, the concentrations of Ca 2+ and HCO 3 - in the groundwater fluctuated notably, and the groundwater flowing along the interbedded layer was dominated by groundwater from the limestone layer. These suggest that groundwater along the interbedded layer may affect the stability of rock slopes.

A Science-Based Understanding of Cermet Processing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cesarano, III, Joseph; Roach, Robert Allen; Kilgo, Alice C.

2006-04-01

This report is a summary of the work completed in FY01 for science-based characterization of the processes used to fabricate 1) cermet vias in source feedthrus using slurry and paste-filling techniques and 2) cermet powder for dry pressing. Common defects found in cermet vias were characterized based on the ability of subsequent processing techniques (isopressing and firing) to remove the defects. Non-aqueous spray drying and mist granulation techniques were explored as alternative methods of creating CND50, the powder commonly used for dry pressed parts. Compaction and flow characteristics of these techniques were analyzed and compared to standard dry-ball-milled CND50. Duemore » to processing changes, changes in microstructure can occur. A microstructure characterization technique was developed to numerically describe cermet microstructure. Machining and electrical properties of dry pressed parts were also analyzed and related to microstructure using this analytical technique.3 Executive SummaryThis report outlines accomplishments in the science-based understanding of cermet processing up to fiscal year 2002 for Sandia National Laboratories. The three main areas of work are centered on 1) increasing production yields of slurry-filled cermets, 2) evaluating the viability of high-solids-loading pastes for the same cermet components, and 3) optimizing cermet powder used in pressing processes (CND50). An additional development that was created as a result of the effort to fully understand the impacts of alternative processing techniques is the use of analytical methods to relate microstructure to physical properties. Recommendations are suggested at the end of this report. Summaries of these four efforts are as follows:1.Increase Production Yields of Slurry-Filled Cermet Vias Finalized slurry filling criteria were determined based on three designs of experiments where the following factors were analyzed: vacuum time, solids loading, pressure drop across the filter paper, slurry injection rate, via prewetting, slurry injection angle, filter paper prewetting, and slurry mixing time. Many of these factors did not have an influence on defect formation. In order of decreasing importance, critical factors for defect formation by slurry filling are vacuum time (20 sec. optimal), slurry solids loading (20.0 g of cermet with 13.00 g of DGBEA solvent (21.2 vol%)), filling with the pipette in a vertical position, and faster injection rates (%7E765 l/s) as preferable to slower. No further recommendations for improvement to this process can be suggested. All findings of the slurry filling process have been transferred to CeramTec, the supplier. Paste filling methods appear to show more promise of increasing production yields. The types of flaws commonly found in slurry-filled vias were identified and followed throughout the entire source feedthru process. In general, all sizes of cracks healed during isopressing and firing steps. Additionally, small to medium sized voids (less than 1/3 the via diameter) can be healed. Porosity will usually lead to via necking, which may cause the part to be out of specification. Large voids (greater 4 than 1/3 of the diameter) and partial fills are not healed or produce significant necking. 2.Viability of High-Solids-Loading-Cermet Paste for Filling Source Feedthru ViaThe paste-filling process is easy to implement and easier to use. The high solids loading (>40 vol %) reduces the incidence of drying defects, which are seen in slurry filled (%7E23 vol %) vias. Additionally, the way in which the vias are filled (the paste is pushed from entrance to exit, displacing air as the paste front progresses), reduces the chance of entrapped voids, which are common in the slurry filling process. From the fair number of samples already filled, the likelihood of this process being a viable and reliable process is very good. Issues of concern for the paste process, as with any new process, are any problems that may arise in subsequent manufacturing stages of the neutron tube that may be affected by subtle changes in microstructure. Both MC4277 and MC4300-type source feedthrus were paste-filled by hand. X-ray analysis showed a much lower existence of voids in the green parts as compared to slurry-filled parts. The paste shows improvements in shelf life (weeks) as compared to slurry (minutes). This method of introducing the cermet to the via also lends itself very well to an automated filling process where a machine can either drill vias or, with the aid of a vision system, find pre-drilled vias and fill them with paste. The pastes used in this work prove the concept of this automated filling process as MC4277 sources have been filled using such a prototype machine, however, better performing pastes can be developed which are less hazardous (aqueous systems). The paste process was also used to successfully fill MC4300 "dogleg" type sources.3.Optimize CND50 Two methods of creating granulated cermet powder for comparison with dry-ball milled CND50 were explored. The first method, non-aqueous spray drying, was performed at Niro Inc. used a 40/60 (wt %) ethanol/toluene solvent and three binder systems; polyvinyl butyral (B79), ethylcellulose (Ethocel), and hydroxypropylcellulose (Klucel). Due to the nature of small spray-dry systems, an excess amount of fines was present in the granulated powder, which may have contributed to the low angles of repose (68 to 78). This is a moderate increase in 5 flowability as standard dry-ball milled powder possesses an angle of repose of 79-89. Mist granulated powders were produced with a tert-butanol solvent and polyvinyl butyral binder system. The angles of repose were more promising (28). More investigation into the mist granulation method is required. Also, aqueous spray drying may be possible with cermet and should be explored. Compaction of all granulated powders is much closer to a proven pressing powder (Sandi94 - angle of repose 29) which should allow cermet to be pressed to near net shape where die filling is difficult for non-flowing powders.4.Microstructure Characterization An analytical technique was developed to numerically characterize microstructures in terms of molybdenum dispersion, homogeneity, and percolation indices. This technique was applied to dry-ball-milled samples of various ball-milling times (0.5 to 20 hours). Significant change in the microstructure could be seen with milling time. Increased milling time caused agglomeration of molybdenum particles, increasing the percolation index, whereas short milling times promoted higher dispersion indices. This phenomenon is contrary to conventional understanding of mixing. However, conventional ball milling does not usually incorporate granules with binder and separate particles. This discrepancy may explain the odd mixing behavior. It is important to note that the high percolation index possessed by long ball mill times showed lower electrical resistance than low-percolation-index microstructures. However, machinability of high percolation, low-dispersion-index microstructures were poor as compared to microstructures with high dispersion indices and moderate percolation indices. This trade-off between dispersion and percolation (at constant molybdenum levels) suggests that microstructures can be achieved that posses good mechanical and electrical properties. Coincidentally, microstructures that satisfy this condition are produced by the standard dry-ball-milled CND50 (4 hour ball mill time). The performance and sensitivity of the microstructure characterization technique should be evaluated, specifically for electrical conductivity. Processing techniques to decrease the percolation index (lowering molybdenum content, excess ball milling, 6 larger molybdenum particles, etc.) should be employed to determine the point where cermet is not conductive or falls below electrical conduction specifications.7« less

Method for molding ceramic powders using a water-based gel casting process

DOEpatents

Jenny, Mark A.; Omalete, Ogbemi O.

1992-09-08

A method for molding ceramic powders comprises forming a slurry mixture including ceramic powder, a dispersant, and a monomer solution. The monomer solution includes at least one monofunctional monomer and at least one difunctional monomer, a free-radical initiator, and a aqueous solvent. The slurry mixture is transferred to a mold, and the mold containing the slurry mixture is heated to polymerize and crosslink the monomer and form a firm polymer-solvent gel matrix. The solid product may be removed from the mold and heated to first remove the solvent and subsequently remove the polymer, whereafter the product may be sintered.

Toward practical all-solid-state lithium-ion batteries with high energy density and safety: Comparative study for electrodes fabricated by dry- and slurry-mixing processes

NASA Astrophysics Data System (ADS)

Nam, Young Jin; Oh, Dae Yang; Jung, Sung Hoo; Jung, Yoon Seok

2018-01-01

Owing to their potential for greater safety, higher energy density, and scalable fabrication, bulk-type all-solid-state lithium-ion batteries (ASLBs) employing deformable sulfide superionic conductors are considered highly promising for applications in battery electric vehicles. While fabrication of sheet-type electrodes is imperative from the practical point of view, reports on relevant research are scarce. This might be attributable to issues that complicate the slurry-based fabrication process and/or issues with ionic contacts and percolation. In this work, we systematically investigate the electrochemical performance of conventional dry-mixed electrodes and wet-slurry fabricated electrodes for ASLBs, by varying the different fractions of solid electrolytes and the mass loading. This information calls for a need to develop well-designed electrodes with better ionic contacts and to improve the ionic conductivity of solid electrolytes. As a scalable proof-of-concept to achieve better ionic contacts, a premixing process for active materials and solid electrolytes is demonstrated to significantly improve electrochemical performance. Pouch-type 80 × 60 mm2 all-solid-state LiNi0·6Co0·2Mn0·2O2/graphite full-cells fabricated by the slurry process show high cell-based energy density (184 W h kg-1 and 432 W h L-1). For the first time, their excellent safety is also demonstrated by simple tests (cutting with scissors and heating at 110 °C).

The importance of the location of sodium chlorite application in a multipollutant flue gas cleaning system.

PubMed

Krzyzynska, Renata; Hutson, Nick D

2012-06-01

In this study, removing sulfur dioxide (SO2), nitrogen oxides (NO(x)), and mercury (Hg) from simulated flue gas was investigated in two laboratory-sized bubbling reactors that simulated an oxidizing reactor (where the NO and Hg(0) oxidation reactions are expected to occur) and a wet limestone scrubber, respectively. A sodium chlorite solution was used as the oxidizing agent. The sodium chlorite solution was an effective additive that enhanced the NO(x), Hg, and SO2 capture from the flue gas. Furthermore, it was discovered that the location of the sodium chlorite application (before, in, or after the wet scrubber) greatly influences which pollutants are removed and the amount removed. This effect is related to the chemical conditions (pH, absence/presence of particular gases) that are present at different positions throughout the flue gas cleaning system profile. The research results indicated that there is a potential to achieve nearly zero SO2, NO(x), and Hg emissions (complete SO2, NO, and Hg removals and -90% of NO(x) absorption from initial values of 1500 ppmv of SO2, 200 ppmv of NO(x), and 206 microg/m3 of Hg(0)) from the flue gas when sodium chlorite was applied before the wet limestone scrubber. However applying the oxidizer after the wet limestone scrubber was the most effective configuration for Hg and NO(x) control for extremely low chlorite concentrations (below 0.002 M) and therefore appears to be the best configuration for Hg control or as an additional step in NO(x) recleaning (after other NO(x) control facilities). The multipollutant scrubber, into which the chlorite was injected simultaneously with the calcium carbonate slurry, appeared to be the least expensive solution (when consider only capital cost), but exhibited the lowest NO(x) absorption at -50%. The bench-scale test results presented can be used to develop performance predictions for a full- or pilot-scale multipollutant flue gas cleaning system equipped with wet flue gas desulfurization scrubber.

Laboratory studies on the rheology of cryogenic slurries with implications for icy satellites

NASA Astrophysics Data System (ADS)

Carey, Elizabeth; Mitchell, Karl; Choukroun, Mathieu; Zhong, Fang

2015-04-01

Interpretation of Cassini RADAR and VIMS data has suggested some landforms on Titan may be due to effusive cryovolcanic processes that created cones, craters and flows. High-resolution Voyager 2 images of Triton also show strong evidence of cryovolcanic features. Fundamental to modeling of cryovolcanic features is the understanding of the rheological properties of cryogenic icy slurries in a thermodynamic and fluid mechanical context, i.e., how they deform and flow or stall under an applied stress. A series of measurements were performed on methanol-water mixtures and ammonia-water mixtures. We measured the rheology of the slurries as a function of temperature and strain rate, which revealed development of yield stress-like behaviors, shear-rate dependence, and thixotropic behavior, even at relatively low crystal fractions. Visualization of icy slurries supports the current hypothesis that crystallization dominates rheological properties. We shall discuss these findings and their implications for cryovolcanism on icy satellites.

Preliminary Toxicological Analysis of the Effect of Coal Slurry Impoundment Water on Human Liver Cells

USGS Publications Warehouse

Bunnell, Joseph E.

2008-01-01

Coal is usually 'washed' with water and a variety of chemicals to reduce its content of sulfur and mineral matter. The 'washings' or 'coal slurry' derived from this process is a viscous black liquid containing fine particles of coal, mineral matter, and other dissolved and particulate substances. Coal slurry may be stored in impoundments or in abandoned underground mines. Human health and environmental effects potentially resulting from leakage of chemical substances from coal slurry into drinking water supplies or aquatic ecosystems have not been systematically examined. Impoundments are semipermeable, presenting the possibility that inorganic and organic substances, some of which may be toxic, may contaminate ground or surface water. The Agency for Toxic Substances and Disease Registry, part of the Centers for Disease Control and Prevention, has concluded that well water in Mingo County, West Virginia, constitutes a public health hazard.

Prevention of deleterious deposits in a coal liquefaction system

DOEpatents

Carr, Norman L.; Prudich, Michael E.; King, Jr., William E.; Moon, William G.

1984-07-03

A process for preventing the formation of deleterious coke deposits on the walls of coal liquefaction reactor vessels involves passing hydrogen and a feed slurry comprising feed coal and recycle liquid solvent to a coal liquefaction reaction zone while imparting a critical mixing energy of at least 3500 ergs per cubic centimeter of reaction zone volume per second to the reacting slurry.

METHOD OF MAKING UO$sub 2$-Bi SLURRIES

DOEpatents

Hahn, H.T.

1960-05-24

A process is given of preparing an easily dispersible slurry of uranium dioxide in bismuth. A mixture of bismuth oxide, uranium, and bismuth are heated in a capsule to a temperature over the melting point of bismuth oxide. The amount of bismuth oxide used is less than that stoichiometrically required because the oxygen in the capsule also enters into the reaction.

Experimental and numerical studies on laser-based powder deposition of slurry erosion resistant materials

NASA Astrophysics Data System (ADS)

Balu, Prabu

Slurry erosion (the removal of material caused by the randomly moving high velocity liquid-solid particle mixture) is a serious issue in crude oil drilling, mining, turbines, rocket nozzles, pumps, and boiler tubes that causes excessive downtime and high operating costs as a result of premature part failure. The goal of this research is to enhance the service life of high-value components subjected to slurry erosion by utilizing the concept of functionally graded metal-ceramic composite material (FGMCCM) in which the favorable properties of metal (toughness, ductility, etc.) and ceramic (hardness) are tailored smoothly to improve erosion resistance. Among the potential manufacturing processes, such as the laser-based powder deposition (LBPD), the plasma transferred arc (PTA), and the thermal spray the LBPD process offers good composition and microstructure control with a high deposition rate in producing the FGMCCM. This research focuses on the development of nickel-tungsten carbide (Ni-WC) based FGMCCM using the LBPD process for applications the above mentioned. The LBPD of Ni-WC involves the introduction of Ni and WC powder particle by an inert gas into the laser-formed molten pool at the substrate via nozzles. The LBPD of Ni-WC includes complex multi-physical interactions between the laser beam, Ni-WC powder, substrate, and carrier and shielding gases that are governed by a number of process variables such as laser power, scanning speed, and powder flow rate. In order to develop the best Ni-WC based slurry erosion resistant material using the LBPD process, the following challenges associated with the fabrication and the performance evaluation need to be addressed: 1) flow behavior of the Ni-WC powder and its interaction with the laser, 2) the effect of the process variables, the material compositions, and the thermo-physical properties on thermal cycles, temperature gradient, cooling rate, and residual stress formation within the material and the subsequent cracking issue, and 3) the effect of composition and composition gradient of Ni and WC on the slurry erosion resistance over a wide range of erosion conditions. This thesis presents a set of numerical and experimental methods in order to address the challenges mentioned above. A three-dimensional (3-D) computational fluid dynamics (CFD) based powder flow model and three vision based techniques were developed in order to visualize the process of feeding the Ni-WC powder in the LBPD process. The results provide the guidelines for efficiently feeding the Ni-WC composite powder into the laser-formed molten pool. The finite element (FE) based experimentally verified 3-D thermal and thermo-mechanical models are developed in order to understand the thermal and stress evolutions in Ni-WC composite material during the LBPD process. The models address the effect of the process variables, preheating temperature, and different mass fractions of WC in Ni on thermal cycles and stress distributions within the deposited material. The slurry erosion behavior of the single and multilayered deposits of Ni-WC composite material produced by the LBPD process is investigated using an accelerated slurry erosion testing machine and a 3-D FE dynamic model. The verified model is used to identify the appropriate composition and composition gradient of Ni-WC composite material required to achieve erosion resistance over a wide range of erosion conditions.

Regeneration of barium carbonate from barium sulphide in a pilot-scale bubbling column reactor and utilization for acid mine drainage.

PubMed

Mulopo, J; Zvimba, J N; Swanepoel, H; Bologo, L T; Maree, J

2012-01-01

Batch regeneration of barium carbonate (BaCO(3)) from barium sulphide (BaS) slurries by passing CO(2) gas into a pilot-scale bubbling column reactor under ambient conditions was used to assess the technical feasibility of BaCO(3) recovery in the Alkali Barium Calcium (ABC) desalination process and its use for sulphate removal from high sulphate Acid Mine Drainage (AMD). The effect of key process parameters, such as BaS slurry concentration and CO(2) flow rate on the carbonation, as well as the extent of sulphate removal from AMD using the recovered BaCO(3) were investigated. It was observed that the carbonation reaction rate for BaCO(3) regeneration in a bubbling column reactor significantly increased with increase in carbon dioxide (CO(2)) flow rate whereas the BaS slurry content within the range 5-10% slurry content did not significantly affect the carbonation rate. The CO(2) flow rate also had an impact on the BaCO(3) morphology. The BaCO(3) recovered from the pilot-scale bubbling column reactor demonstrated effective sulphate removal ability during AMD treatment compared with commercial BaCO(3).

Assessment of Environmental Impacts of Limestone Quarrying Operations in Thailand

NASA Astrophysics Data System (ADS)

Kittipongvises, Suthirat

2017-11-01

Environmental impacts of the mineral extraction have been a public concern. Presently, there is widespread global interest in the area of mining and its sustainability that focused on the need to shift mining industry to a more sustainable framework. The aim of this study was to systematically assess all possible environmental and climate change related impacts of the limestone quarrying operation in Thailand. By considering the life cycle assessment method, the production processes were divided into three phases: raw material extraction, transportation, and comminution. Both IMPACT 2002+ and the Greenhouse Gas Protocol methods were used. Results of IMPACT 2002+ analysis showed that per 1 ton crushed limestone rock production, the total depletion of resource and GHGs emissions were 79.6 MJ and 2.76 kg CO2 eq., respectively. Regarding to the four damage categories, `resources' and `climate change' categories were the two greatest environmental impacts of the limestone rock production. Diesel fuel and electricity consumption in the mining processes were the main causes of those impacts. For climate change, the unit of CO2 eq. was expressed to quantify the total GHGs emissions. Estimated result was about 3.13 kg CO2 eq. per ton limestone rock product. The results obtained by the Greenhouse Gas Protocol were also similar to IMPACT 2002+ method. Electrical energy consumption was considered as the main driver of GHGs, accounting for approximately 46.8 % of total fossil fuel CO2 emissions. A final point should be noted that data uncertainties in environmental assessment over the complete life cycle of limestone quarrying operation have to be carefully considered.

Modifying the properties of finely ground limestone by tumbling granulation

NASA Astrophysics Data System (ADS)

Macho, Oliver; Eckert, Maroš; Tomášová, Barbora; Peciar, Peter; Ščasný, Martin; Fekete, Roman; Peciar, Marián

2016-06-01

Calcium carbonate in the form of finely ground limestone is a material that has found its application in a wide range of industries, in the chemical, rubber, agricultural, and paper industries, is used for desulfurization of boilers and other. In civil engineering, ground limestone is used for the production of building materials, plaster and mortar mixtures, as a filler in concrete mixtures, in road construction, and as an essential component of mastic asphalt. This paper deals with examining the modification of the properties of finely ground limestone by the tumbling agglomeration method. It has been shown that the components of concrete with a round grain have a positive effect on the pumping of concrete in comparison with an elongated grain or the rough surface of crushed stone. The experiments will be carried out on a granulation plate using a variety of granulation liquid. The agglomerates and their properties were compared with untreated finely ground limestone, with a focus on detecting changes in compressibility, density and particle size. The output of this paper is a description and graphical representation of the changes in the properties of ground limestone before and after the agglomeration process.

Effects of total solids concentrations of poultry, cattle, and piggery waste slurries on biogas yield

DOE Office of Scientific and Technical Information (OSTI.GOV)

Itodo, I.N.; Awulu, J.O.

1999-12-01

The effects of total solids concentrations of poultry, cattle and piggery waste slurries on biogas yield was investigated. Twelve laboratory-size anaerobic batch digesters with 25 L volume were constructed and used for the experiments. Three replicates of 5%, 10%, 15%, and 20% TS concentrations of poultry, cattle, and piggery waste slurries were anaerobically digested for a 30-day detention period and gas yield was measured by the method of water displacement. Temperature variation within the digesters was measured with a maximum and minimum thermometer. Anaerobic digestion of the slurries was undertaken in the mesophilic temperature range (20--40 C). The carbon:nitrogen ratiomore » of each of the slurries digested was determined. The carbon content was determined using the wackley-Black method, and nitrogen content was determined by the regular kjeldhal method. The pH was measured weekly during the period of digestion from a digital pH meter. Gas quality (% methane fraction) was also measured weekly from an analyzer. Coefficient of variation was computed to ascertain the status of the digestion process. Analysis of variance was used to determine the significant difference in gas yield at p < 0.05. Duncan's New Multiple Range Test at p < 0.05 was used to analyze the difference in gas yield among the various TS concentrations of the slurries investigated. The results indicate that biogas yield is of the order: 5% TS > 10% TS > 15% TS > 20% TS. This result shows that gas yield increases with decreasing TS concentration of the slurries. The ANOVA showed that the gas yield from the various TS % was significantly different (p < 0.05). DNMRT showed that there was significant difference in gas yield from the slurries and wastetypes investigated. Poultry waste slurries had the greatest gas yield (L CH4/kg TS) as the gas yield from the waste types was of the order: Poultry > Piggery > Cattle. The pH of the slurries was of the range 5.5 to 6.8 (weakly acidic). The C:N of the slurries varied between 6:1 and 9:1. The Coefficient of Variation (CV) for 10 consecutive days of digestion was less than 10% indicating a steady state in all the digesters.« less

Lithologic and structural controls of limestone-hosted Pb-Zn-Ag mineralization in Chihuahua, Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lofquist, D.J.; Ruiz, J.

1985-01-01

The state of Chihuahua contains some of the most important limestone-hosted ore deposits in Mexico. The best example are Santa Eulalia and Naica which together have produced 53 million tons or ore averaging 7.7% Pb, 6.4% Zn, and 280 g/ton Ag. These deposits occur as mantos and chimneys often accompanied by calc-silicates. Among the most critical questions in this type of deposit is the control that the limestone-host exerts on the mineralizing process. Here the authors present the first detailed data on the stratigraphic and lithologic character of the limestone-hosts at Naica and Santa Eulalia. All ore at Naica andmore » Santa Eulalia is hosted by micrites, biomicrites and biosparites indicative of generally quiet marine deposition. The authors work suggests that the western edge of the this trough might be a low angle, east dipping ramp which extends below the Sierra Madre Occidental. The primary permeability of the limestone that hosts Naica and Santa Eulalia is in the micro to nanodarcy range. The effective permeability has been augmented by 3 or 4 stages of micro-fracturing. Most of the ore is controlled by these fractures and by felsic dikes, which in cases are mostly endoskarn. Stylolites also appear to have exerted a control on the mineralizing process. Numerous instances of alteration and recrystallization confined to one side of a horizontal stylolite have been noted. At Santa Eulalia, horizontal stylolites have controlled the emplacement of massive sulfide mantos, suggesting that the mineralizing process was rather passive.« less

Investigations of a Cretaceous limestone with spectral induced polarization and scanning electron microscopy

NASA Astrophysics Data System (ADS)

Johansson, Sara; Sparrenbom, Charlotte; Fiandaca, Gianluca; Lindskog, Anders; Olsson, Per-Ivar; Dahlin, Torleif; Rosqvist, Håkan

2017-02-01

Characterization of varying bedrock properties is a common need in various contexts, ranging from large infrastructure pre-investigations to environmental protection. A direct current resistivity and time domain induced polarization (IP) survey aiming to characterize properties of a Cretaceous limestone was carried out in the Kristianstad basin, Sweden. The time domain IP data was processed with a recently developed method in order to suppress noise from the challenging urban setting in the survey area. The processing also enabled extraction of early decay times resulting in broader spectra of the time decays and inversion for Cole-Cole parameters. The aims of this study is to investigate if large-scale geoelectrical variations as well as small-scale structural and compositional variations exist within the Kristianstad limestone, and to evaluate the usefulness of Cole-Cole inverted IP data in early time ranges for bedrock characterization. The inverted sections showed variations within the limestone that could be caused by variations in texture and composition. Samples from a deep drilling in the Kristianstad basin were investigated with scanning electron microscopy and energy dispersive X-ray spectroscopy, and the results showed that varying amounts of pyrite, glauconite and clay matrix were present at different levels in the limestone. The local high IP anomalies in the limestone could be caused by these minerals otherwise the IP responses were generally weak. There were also differences in the texture of the limestone at different levels, governed by fossil shapes and composition, proportions of calcareous cement and matrix as well as amount of silicate grains. Textural variations may have implications on the variation in Cole-Cole relaxation time and frequency factor. However, more research is needed in order to directly connect microgeometrical properties in limestone to spectral IP responses. The results from this study show that it is possible to recover useable spectral information from early decay times. We also show that under certain conditions (e.g. relatively short relaxation times in the subsurface), it is possible to extract spectral information from time domain IP data measured with on-off times as short as 1 s.

Figure and caption for LDRD annual report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suratwala, T.

2017-10-16

Material removal rate of various optical material workpieces polished using various colloidal slurries as a function of partial charge difference. Partial charge difference is a parameter calculated from a new chemical model proposed to link the condensation reaction rate with polishing material removal rate. This chemical model can serve as a global platform to predict & design polishing processes for a wide variety of workpiece materials and slurry compositions.

Geomorphological map of a coastal stretch of north-eastern Gozo (Maltese archipelago, Mediterranean Sea)

NASA Astrophysics Data System (ADS)

Soldati, Mauro; Micallef, Anton; Biolchi, Sara; Chelli, Alessandro; Cuoghi, Alessandro; Devoto, Stefano; Gauci, Christopher; Graff, Kevin; Lolli, Federico; Mantovani, Matteo; Mastronuzzi, Giuseppe; Pisani, Luca; Prampolini, Mariacristina; Restall, Brian; Roulland, Thomas; Saliba, Michael; Selmi, Lidia; Vandelli, Vittoria

2017-04-01

Geomorphological investigations carried out along the north-eastern coast of the Island of Gozo (Malta) have led to the production of a detailed geomorphological map. Field surveys, accompanied by aerial photo-interpretation, were carried out within the framework of the EUR-OPA Major Hazards Agreement Project ``Developing Geomorphological mapping skills and datasets in anticipation of subsequent Susceptibility, Vulnerability, Hazard and Risk Mapping'' (Council of Europe). In particular, this geomorphological map is the main output of a `Training Course on Geomorphological Mapping in Coastal Areas' held within the Project in November 2016. The study area selected was between Ramla Bay and Dacrhlet Qorrot Bay on the Island of Gozo (67 km2), part of the Maltese archipelago in the central Mediterranean Sea. From a geological viewpoint, the stratigraphic sequence includes Late Oligocene (Chattian) to Late Miocene (Messinian) sedimentary rocks. The hard limestones of the Upper Coralline Limestone Formation, the youngest lithostratigraphic unit, dominate the study area. Underlying this formation, marls and clays belonging to the Blue Clay Formation extensively outcrop. The oldest lithostratigraphic unit observed in the study area is the Globigerina Limestone Formation, a fine-grained limestone. The lithostructural features of the outcropping units clearly condition the morphography of the landscape. The coast is characterised by the alternation of inlets and promontories. Worthy of notice is the large sandy beach of Ramla Bay partly backed by dunes. From a geomorphological perspective, the investigated coastal stretch is characterised by limestone plateaus bounded by steep structural scarps which are reshaped by gravitational and/or degradation processes, and milder slopes in Blue Clays at their foot comprising of numerous rock block deposits (rdum in Maltese) and active or abandoned terraced fields used for agricultural purposes. Landforms and processes related to structural, gravitational, coastal, alluvial and karst processes were mapped. Particular attention was devoted to the recognition and classification of landslides of different type (in particular block slides and earth flows/slides) which affect large sectors of the north-eastern coast of Gozo. In most cases, landslide accumulations reach the coastline and cover shore platforms. In addition, wide portions of the plateau areas are affected by rock spreading related to the presence of limestones overlying clayey terrains. The climatic conditions, the dense joint systems and the karstification of limestone determine a temporary superficial drainage pattern. Temporary streambeds (wieden in Maltese) were identified in correspondence of V-shaped valleys once occupied by permanent water courses. Karst processes widely affect the Upper Coralline Limestone Formation resulting in caves, diffuse solution pools, grooves and furrows. The geomorphological map output represents a baseline document on which to undertake, first the landslide susceptibility mapping, subsequently the hazard mapping and finally the risk mapping, a critical part of the wider-scoped risk management process of this and similar coastal areas.

METHOD OF DISSOLVING REFRACTORY ALLOYS

DOEpatents

Helton, D.M.; Savolainen, J.K.

1963-04-23

This patent relates to the dissolution of alloys of uranium with zirconium, thorium, molybdenum, or niobium. The alloy is contacted with an anhydrous solution of mercuric chloride in a low-molecular-weight monohydric alcohol to produce a mercury-containing alcohol slurry. The slurry is then converted to an aqueous system by adding water and driving off the alcohol. The resulting aqueous slurry is electrolyzed in the presence of a mercury cathode to remove the mercury and produce a uranium-bearing aqueous solution. This process is useful for dissolving irradiated nuclear reactor fuels for radiochemical reprocessing by solvent extraction. In addition, zirconium-alloy cladding is selectively removed from uranium dioxide fuel compacts by this means. (AEC)

Method for simultaneous use of a single additive for coal flotation, dewatering, and reconstitution

DOEpatents

Wen, Wu-Wey; Gray, McMahan L.; Champagne, Kenneth J.

1995-01-01

A single dose of additive contributes to three consecutive fine coal unit operations, i.e., flotation, dewatering and reconstitution, whereby the fine coal is first combined with water in a predetermined proportion so as to formulate a slurry. The slurry is then mixed with a heavy hydrocarbon-based emulsion in a second predetermined proportion and at a first predetermined mixing speed and for a predetermined period of time. The conditioned slurry is then cleaned by a froth flotation method to form a clean coal froth and then the froth is dewatered by vacuum filtration or a centrifugation process to form reconstituted products that are dried to dust-less clumps prior to combustion.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yao, S.C.

The combustion of single coal-water slurry droplet with oil as combustion additive (CWOM) has been studied. In this study, the droplet is suspended on a fine quartz fiber and is exposed to the hot combustion product of propane (C/sub 3/H/sub 8/) and air. The results are documented in a movie series. The combustion of CWOM with various combinations of concentrations are compared with that of coal-water slurry and water-oil mixture droplets. The combustion of coal-water slurry is enhanced significantly due to the presence of emulsified kerosene. The enhancement is also dependent upon the mixing procedure during preparation of CWOM. Themore » presence of emulsified kerosene induces local boil-off and combustion that coal particles are splashed as fire works during the early evaporation stage of droplet heat-up. After particle splashing, blow-holes appear on the droplet surface. The popcorn and swelling phenomena usually occurred in coal-water-slurry combustion is greatly reduced. Significant combustion enhancement occurs with the use of kerosene in an amount of about 15 percent of the overall CWOM. This process of using kerosene as combustion additive may provide obvious advantage for the combustion of bituminous coal-water slurry. 4 references, 6 figures.« less

Cross-flow electrofilter and method

DOEpatents

Gidaspow, Dimitri; Lee, Chang H.; Wasan, Darsh T.

1980-01-01

A filter for clarifying carbonaceous liquids containing finely divided solid particles of, for instance, unreacted coal, ash and other solids discharged from a coal liquefaction process is presented. The filter includes two passageways separated by a porous filter medium. In one preferred embodiment the filter medium is of tubular shape to form the first passageway and is enclosed within an outer housing to form the second passageway within the annulus. An electrode disposed in the first passageway, for instance along the tube axis, is connected to a source of high voltage for establishing an electric field between the electrode and the filter medium. Slurry feed flows through the first passageway tangentially to the surfaces of the filter medium and the electrode. Particles from the feed slurry are attracted to the electrode within the first passageway to prevent plugging of the porous filter medium while carbonaceous liquid filters into the second passageway for withdrawal. Concentrated slurry is discharged from the first passageway at an end opposite to the feed slurry inlet. Means are also provided for the addition of diluent and a surfactant into the slurry to control relative permittivity and the electrophoretic mobility of the particles.

Cross flow electrofilter and method

DOEpatents

Gidaspow, Dimitri; Lee, Chang H.; Wasan, Darsh T.

1981-01-01

A filter for clarifying carbonaceous liquids containing finely divided solid particles of, for instance, unreacted coal, ash and other solids discharged from a coal liquefaction process is presented. The filter includes two passageways separated by a porous filter medium. In one preferred embodiment the filter medium is of tubular shape to form the first passageway and is enclosed within an outer housing to form the second passageway within the annulus. An electrode disposed in the first passageway, for instance along the tube axis, is connected to a source of high voltage for establishing an electric field between the electrode and the filter medium. Slurry feed flows through the first passageway tangentially to the surfaces of the filter medium and the electrode. Particles from the feed slurry are attracted to the electrode within the first passageway to prevent plugging of the porous filter medium while carbonaceous liquid filters into the second passageway for withdrawal. Concentrated slurry is discharged from the first passageway at an end opposite to the feed slurry inlet. Means are also provided for the addition of diluent and a surfactant into the slurry to control relative permittivity and the electrophoretic mobility of the particles.

Reduction of Methane Emission during Slurry Storage by the Addition of Effective Microorganisms and Excessive Carbon Source from Brewing Sugar.

PubMed

Bastami, Mohd Saufi B; Jones, Davey L; Chadwick, David R

2016-11-01

Storing livestock manure is the primary stage of manure management where microbial processes and chemical reactions result in the release of methane (CH), nitrous oxide (NO), ammonia (NH), and carbon dioxide (CO). This study examined the reduction of CH emissions from slurry storage under two temperatures (cool [10°C] and warm [30°C]) when a glucose-rich substrate (brewing sugar) and activated effective microorganisms were applied at 10% (w/w) and 5% (v/w), respectively. Brewing sugar addition influenced microbial anaerobic respiration, resulting in a reduction of slurry pH to <5.0, through "self-acidification" caused by lactic acid production. Subsequently, CH emissions were significantly reduced by 87 and 99% in the cool and warm environments, respectively. The effective microorganism treatment did not change the chemical characteristics of the slurry but reduced CH emissions by 17 and 27% ( < 0.05) in the cool and warm environments, respectively. These results suggest that self-acidification after addition of a carbon source may be a promising alternative to slurry acidification using concentrated acids. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Effect of H2O2 and nonionic surfactant in alkaline copper slurry

NASA Astrophysics Data System (ADS)

Haobo, Yuan; Yuling, Liu; Mengting, Jiang; Guodong, Chen; Weijuan, Liu; Shengli, Wang

2015-01-01

For improving the polishing performance, in this article, the roles of a nonionic surfactant (Fatty alcohol polyoxyethylene ether) and H2O2 were investigated in the chemical mechanical planarization process, respectively. Firstly, the effects of the nonionic surfactant on the within-wafer non-uniformity (WIWNU) and the surface roughness were mainly analyzed. In addition, the passivation ability of the slurry, which had no addition of BTA, was also discussed from the viewpoint of the static etch rate, electrochemical curve and residual step height under different concentrations of H2O2. The experimental results distinctly revealed that the nonionic surfactant introduced in the slurry improved the WIWNU and surface roughness, and that a 2 vol% was considered as an appropriate concentration relatively. When the concentration of H2O2 surpasses 3 vol%, the slurry will possess a relatively preferable passivation ability, which can effectively decrease the step height and contribute to acquiring a flat and smooth surface. Hence, based on the result of these experiments, the influences of the nonionic surfactant and H2O2 are further understood, which means the properties of slurry can be improved.

Particle morphology characterization and manipulation in biomass slurries and the effect on rheological properties and enzymatic conversion.

PubMed

Dibble, Clare J; Shatova, Tatyana A; Jorgenson, Jennie L; Stickel, Jonathan J

2011-01-01

An improved understanding of how particle size distribution relates to enzymatic hydrolysis performance and rheological properties could enable enhanced biochemical conversion of lignocellulosic feedstocks. Particle size distribution can change as a result of either physical or chemical manipulation of a biomass sample. In this study, we employed image processing techniques to measure slurry particle size distribution and validated the results by showing that they are comparable to those from laser diffraction and sieving. Particle size and chemical changes of biomass slurries were manipulated independently and the resulting yield stress and enzymatic digestibility of slurries with different size distributions were measured. Interestingly, reducing particle size by mechanical means from about 1 mm to 100 μm did not reduce the yield stress of the slurries over a broad range of concentrations or increase the digestibility of the biomass over the range of size reduction studied here. This is in stark contrast to the increase in digestibility and decrease in yield stress when particle size is reduced by dilute-acid pretreatment over similar size ranges. Copyright © 2011 American Institute of Chemical Engineers (AIChE).

Low Cost and Energy Efficient Methods for the Manufacture of Semi-Solid (SSM) Feedstock

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diran Apelian; Qingyue Pan; Makhlouf Makhlouf

2005-11-07

The SSM Consortium (now ACRC) at WPI has been carrying out fundamental, pre-competitive research in SSM for several years. Current and past research (at WPI) has generated many results of fundamental and applied nature, which are available to the SSM community. These include materials characterization, yield stress effects, alloy development, rheological properties, process modeling/simulation, semi-solid slurry formation, etc. Alternative method to produce SSM slurries at lower processing costs and with reduced energy consumption is a critical need. The production of low cost SSM feedstock will certainly lead to a dramatic increase in the tonnage of castings produced by SSM, andmore » will provide end users such as the transportation industry, with lighter, cheaper and high performance materials. In this program, the research team has addressed three critical issues in semi-solid processing. They are: (1) Development of low cost, reliable slurry-on-demand approaches for semi-solid processing; (2) Application of the novel permanent grain refining technology-SiBloy for the manufacture of high-quality SSM feedstock, and (3) Development of computational and modeling tools for semi-solid processing to enhance SSM process control. Salient results from these studies are summarized and detailed in our final technical report.« less

Controls on atrazine leaching through a soil-unsaturated fractured limestone sequence at Brévilles, France.

PubMed

Roulier, Stéphanie; Baran, Nicole; Mouvet, Christophe; Stenemo, Fredrik; Morvan, Xavier; Albrechtsen, Hans-Jørgen; Clausen, Liselotte; Jarvis, Nicholas

2006-03-01

The objective of this study was to identify the main controls on atrazine leaching through luvisols and calcisols overlying fissured limestone using the dual-permeability model MACRO. The model parameterisation was based on a combination of direct measurements (e.g. hydraulic properties, adsorption and degradation), literature data and calibration against bromide leaching experiments in field plots. A Monte Carlo sensitivity analysis was carried out for a typical application pattern, considering two different depths of unsaturated limestone (15 and 30 m). MACRO calibrations to the field experiments demonstrated the occurrence of strong macropore flow in the luvisol, while transport in the calcisol could be described by the advection-dispersion equation. MACRO simulations of tritium and atrazine leaching qualitatively matched tritium concentration profiles measured in the limestone and atrazine concentrations measured in piezometers and in aquifer discharge via a spring. The sensitivity analysis suggested that the thickness of the limestone, as well as the transport properties and processes occurring in the unsaturated rock (e.g. matrix vs. fissure flow) will have little significant long-term effect on atrazine leaching, mainly because degradation is very slow in the limestone. No mineralization of atrazine was detected in one-year incubations and a mean half-life of 10 years was assumed in the simulations. Instead, processes occurring in the soil exerted the main control on predicted atrazine leaching, especially variations in the degradation rate and the strength of sorption and macropore flow. However, fissure flow in unsaturated rock is expected to exert a much more significant control on groundwater contamination for compounds that degrade more readily in the deep vadose zone.

WASTE CONDITIONING FOR TANK HEEL TRANSFER

DOE Office of Scientific and Technical Information (OSTI.GOV)

M.A. Ebadian, Ph.D.

1999-01-01

This report summarizes the research carried out at Florida International University's Hemispheric Center for Environmental Technology (FIU-HCET) for the fiscal year 1998 (FY98) under the Tank Focus Area (TFA) project ''Waste Conditioning for Tank Slurry Transfer.'' The objective of this project is to determine the effect of chemical and physical properties on the waste conditioning process and transfer. The focus of this research consisted in building a waste conditioning experimental facility to test different slurry simulants under different conditions, and analyzing their chemical and physical properties. This investigation would provide experimental data and analysis results that can make the tankmore » waste conditioning process more efficient, improve the transfer system, and influence future modifications to the waste conditioning and transfer system. A waste conditioning experimental facility was built in order to test slurry simulants. The facility consists of a slurry vessel with several accessories for parameter control and sampling. The vessel also has a lid system with a shaft-mounted propeller connected to an air motor. In addition, a circulation system is connected to the slurry vessel for simulant cooling and heating. Experimental data collection and analysis of the chemical and physical properties of the tank slurry simulants has been emphasized. For this, one waste slurry simulant (Fernald) was developed, and another two simulants (SRS and Hanford) obtained from DOE sites were used. These simulants, composed of water, soluble metal salts, and insoluble solid particles, were used to represent the actual radioactive waste slurries from different DOE sites. The simulants' chemical and physical properties analyzed include density, viscosity, pH, settling rate, and volubility. These analyses were done to samples obtained from different experiments performed at room temperature but different mixing time and strength. The experimental results indicate that the viscosity of the slurries follow the Bingham plastic model, especially when the solids concentration is increased. At low concentrations slurries may behave as Newtonian fluids. The three simulants follow a similar settling rate behavior. This behavior can be explained as a combination of one or more decreasing exponential curves. This means that the particle settling rate of the simulants decreases exponentially as time increases. The pH range for the three simulants was from 8 to 13 at all concentrations. The SRS simulant showed the highest pH, around 12; the other two simulants, Hanford and Fernald, had about the same pH range, from 3 to 9. When comparing volubility of the three simulants at the same concentration, SRS simulant showed higher volubility, followed by the Hanford simulant and the Fernald simulant, in that order. Further work is scheduled for next year (FY99) in this project, when other parameters like simulants particle size distribution, particle shape, and crystallization behavior will be studied. The same tests performed this period also will be performed at different temperatures for data comparison.« less

Ultra-porous titanium oxide scaffold with high compressive strength

PubMed Central

Tiainen, Hanna; Lyngstadaas, S. Petter; Ellingsen, Jan Eirik

2010-01-01

Highly porous and well interconnected titanium dioxide (TiO2) scaffolds with compressive strength above 2.5 MPa were fabricated without compromising the desired pore architectural characteristics, such as high porosity, appropriate pore size, surface-to-volume ratio, and interconnectivity. Processing parameters and pore architectural characteristics were investigated in order to identify the key processing steps and morphological properties that contributed to the enhanced strength of the scaffolds. Cleaning of the TiO2 raw powder removed phosphates but introduced sodium into the powder, which was suggested to decrease the slurry stability. Strong correlation was found between compressive strength and both replication times and solid content in the ceramic slurry. Increase in the solid content resulted in more favourable sponge loading, which was achieved due to the more suitable rheological properties of the ceramic slurry. Repeated replication process induced only negligible changes in the pore architectural parameters indicating a reduced flaw size in the scaffold struts. The fabricated TiO2 scaffolds show great promise as load-bearing bone scaffolds for applications where moderate mechanical support is required. PMID:20711636

Making Plant-Support Structures From Waste Plant Fiber

NASA Technical Reports Server (NTRS)

Morrow, Robert C.; < oscjmocl. < attjew K/; {ertzbprm. A,amda; Ej (e. Cjad); Hunt, John

2006-01-01

Environmentally benign, biodegradable structures for supporting growing plants can be made in a process based on recycling of such waste plant fiber materials as wheat straw or of such derivative materials as paper and cardboard. Examples of structures that can be made in this way include plant plugs, pots, planter-lining mats, plant fences, and root and shoot barriers. No chemical binders are used in the process. First, the plant material is chopped into smaller particles. The particles are leached with water or steam to remove material that can inhibit plant growth, yielding a fibrous slurry. If the desired structures are plugs or sheets, then the slurry is formed into the desired shapes in a pulp molding subprocess. If the desired structures are root and shoot barriers, pots, or fences, then the slurry is compression-molded to the desired shapes in a heated press. The processed materials in these structures have properties similar to those of commercial pressboard, but unlike pressboard, these materials contain no additives. These structures have been found to withstand one growth cycle, even when wet

Alloyed coatings for dispersion strengthened alloys

NASA Technical Reports Server (NTRS)

Wermuth, F. R.; Stetson, A. R.

1971-01-01

Processing techniques were developed for applying several diffusion barriers to TD-Ni and TD-NiCr. Barrier coated specimens of both substrates were clad with Ni-Cr-Al and Fe-Cr-Al alloys and diffusion annealed in argon. Measurement of the aluminum distribution after annealing showed that, of the readily applicable diffusion barriers, a slurry applied tungsten barrier most effectively inhibited the diffusion of aluminum from the Ni-Cr-Al clad into the TD-alloy substrates. No barrier effectively limited interdiffusion of the Fe-Cr-Al clad with the substrates. A duplex process was then developed for applying Ni-Cr-Al coating compositions to the tungsten barrier coated substrates. A Ni-(16 to 32)Cr-3Si modifier was applied by slurry spraying and firing in vacuum, and was then aluminized by a fusion slurry process. Cyclic oxidation tests at 2300 F resulted in early coating failure due to inadequate edge coverage and areas of coating porosity. EMP analysis showed that oxidation had consumed 70 to 80 percent of the aluminum in the coating in less than 50 hours.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glosser, D.; Kutchko, B.; Benge, G.

Foamed cement is a critical component for wellbore stability. The mechanical performance of a foamed cement depends on its microstructure, which in turn depends on the preparation method and attendant operational variables. Determination of cement stability for field use is based on laboratory testing protocols governed by API Recommended Practice 10B-4 (API RP 10B-4, 2015). However, laboratory and field operational variables contrast considerably in terms of scale, as well as slurry mixing and foaming processes. Here in this paper, laboratory and field operational processes are characterized within a physics-based framework. It is shown that the “atomization energy” imparted by themore » high pressure injection of nitrogen gas into the field mixed foamed cement slurry is – by a significant margin – the highest energy process, and has a major impact on the void system in the cement slurry. There is no analog for this high energy exchange in current laboratory cement preparation and testing protocols. Quantifying the energy exchanges across the laboratory and field processes provides a basis for understanding relative impacts of these variables on cement structure, and can ultimately lead to the development of practices to improve cement testing and performance.« less

Internal coating of air cooled gas turbine blades

NASA Technical Reports Server (NTRS)

Ahuja, P. L.

1979-01-01

Six coating systems were evaluated for internal coating of decent stage (DS) eutectic high pressure turbine blades. Sequential deposition of electroless Ni by the hydrazine process, slurry Cr, and slurry Al, followed by heat treatment provided the coating composition and thickness for internal coating of DS eutectic turbine blades. Both NiCr and NiCrAl coating compositions were evaluated for strain capability and ductile to brittle transition temperature.

Mechanism analysis on finishing of reaction-sintered silicon carbide by combination of water vapor plasma oxidation and ceria slurry polishing

NASA Astrophysics Data System (ADS)

Shen, Xinmin; Tu, Qunzhang; Deng, Hui; Jiang, Guoliang; Yamamura, Kazuya

2015-05-01

Reaction-sintered silicon carbide (RS-SiC), which is considered as a promising mirror material for space telescope systems, requires a high surface property. An ultrasmooth surface with a Ra surface roughness of 0.480 nm was obtained after water vapor plasma oxidation for 90 min followed by ceria slurry polishing for 40 min. The oxidation process of RS-SiC by water vapor plasma was analyzed based on the Deal-Grove model, and the theoretical calculation results are consistent with the measured data obtained by scanning white light interferometer (SWLI), scanning electron microscopy/energy-dispersive x-ray, and atomic force microscope. The polishing process of oxidized RS-SiC by ceria slurry was investigated according to the Preston equation, which would theoretically forecast the evolutions of RS-SiC surfaces along with the increasing of polishing time, and it was experimentally verified by comparing the surface roughnesses obtained by SWLI and the surface morphologies obtained by SEM. The mechanism analysis on the finishing of RS-SiC would be effective for the optimization of water vapor plasma oxidation parameters and ceria slurry polishing parameters, which will promote the application of RS-SiC substrates by improving the surface property obtained by the oxidation-assisted polishing method.

CHARACTERIZATION OF A PRECIPITATE REACTOR FEED TANK (PRFT) SAMPLE FROM THE DEFENSE WASTE PROCESSING FACILITY (DWPF)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crawford, C.; Bannochie, C.

2014-05-12

A sample of from the Defense Waste Processing Facility (DWPF) Precipitate Reactor Feed Tank (PRFT) was pulled and sent to the Savannah River National Laboratory (SRNL) in June of 2013. The PRFT in DWPF receives Actinide Removal Process (ARP)/ Monosodium Titanate (MST) material from the 512-S Facility via the 511-S Facility. This 2.2 L sample was to be used in small-scale DWPF chemical process cell testing in the Shielded Cells Facility of SRNL. A 1L sub-sample portion was characterized to determine the physical properties such as weight percent solids, density, particle size distribution and crystalline phase identification. Further chemical analysismore » of the PRFT filtrate and dissolved slurry included metals and anions as well as carbon and base analysis. This technical report describes the characterization and analysis of the PRFT sample from DWPF. At SRNL, the 2.2 L PRFT sample was composited from eleven separate samples received from DWPF. The visible solids were observed to be relatively quick settling which allowed for the rinsing of the original shipping vials with PRFT supernate on the same day as compositing. Most analyses were performed in triplicate except for particle size distribution (PSD), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and thermogravimetric analysis (TGA). PRFT slurry samples were dissolved using a mixed HNO3/HF acid for subsequent Inductively Coupled Plasma Atomic Emission Spectroscopy (ICPAES) and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) analyses performed by SRNL Analytical Development (AD). Per the task request for this work, analysis of the PRFT slurry and filtrate for metals, anions, carbon and base were primarily performed to support the planned chemical process cell testing and to provide additional component concentrations in addition to the limited data available from DWPF. Analysis of the insoluble solids portion of the PRFT slurry was aimed at detailed characterization of these solids (TGA, PSD, XRD and SEM) in support of the Salt IPT chemistry team. The overall conclusions from analyses performed in this study are that the PRFT slurry consists of 0.61 Wt.% insoluble MST solids suspended in a 0.77 M [Na+] caustic solution containing various anions such as nitrate, nitrite, sulfate, carbonate and oxalate. The corresponding measured sulfur level in the PRFT slurry, a critical element for determining how much of the PRFT slurry gets blended into the SRAT, is 0.437 Wt.% TS. The PRFT slurry does not contain insoluble oxalates nor significant quantities of high activity sludge solids. The lack of sludge solids has been alluded to by the Salt IPT chemistry team in citing that the mixing pump has been removed from Tank 49H, the feed tank to ARP-MCU, thus allowing the sludge solids to settle out. The PRFT aqueous slurry from DWPF was found to contain 5.96 Wt.% total dried solids. Of these total dried solids, relatively low levels of insoluble solids (0.61 Wt.%) were measured. The densities of both the filtrate and slurry were 1.05 g/mL. Particle size distribution of the PRFT solids in filtered caustic simulant and XRD analysis of washed/dried PRFT solids indicate that the PRFT slurry contains a bimodal distribution of particles in the range of 1 and 6 μm and that the particles contain sodium titanium oxide hydroxide Na2Ti2O4(OH)2 crystalline material as determined by XRD. These data are in excellent agreement with similar data obtained from laboratory sampling of vendor supplied MST. Scanning Electron Microscopy (SEM) combined with Energy Dispersive X-ray Spectroscopy (EDS) analysis of washed/dried PRFT solids shows the particles to be like previous MST analyses consisting of irregular shaped micron-sized solids consisting primarily of Na and Ti. Thermogravimetric analysis of the washed and unwashed PRFT solids shows that the washed solids are very similar to MST solids. The TGA mass loss signal for the unwashed solids shows similar features to TGA performed on cellulose nitrate filter paper indicating significant presence of the deteriorated filter in this unwashed sample. Neither the washed nor unwashed PRFT solids TGA traces showed any features that would indicate presence of sodium oxalate solids. The PRFT Filtrate elemental analysis shows that Na, S and Al are major soluble species with trace levels of B, Cr, Cu, K, Li, Si, Tc, Th and U present. Nitrate, nitrite, sulfate, oxalate, carbonate and hydroxide are major soluble anion species. There is good agreement between the analyzed TOC and the total carbon calculated from the sum of oxalate and minor species formate. Comparison of the amount and speciation of the carbon species between filtrate and slurry indicates no significant carbon-containing species, e.g., sodium oxalate, are present in the slurry solids. Dissolution of the PRFT slurry and subsequent analysis shows that Na, Ti, Si and U are the major elements present on a Wt.% total dried solids basis with 30, 5.8 and 0.47 and 0.11 Wt.% total dried solids, respectively. The amount of Al in the dissolved PRFT slurry is less than that calculated from the PRFT filtrate alone which suggests that the mixed acid digestion used in this work is not optimized for Al recovery. The concentrations of Ca, Fe, Hg and U are all low (at or below 0.11 wt%) and there is no detectable Mn or Ni present which indicates no significant HLW sludge solids are present in the PRFT slurry sample.« less

The impact of wet flue gas desulfurization scrubbing on mercury emissions from coal-fired power stations.

PubMed

Niksa, Stephen; Fujiwara, Naoki

2005-07-01

This article introduces a predictive capability for Hg retention in any Ca-based wet flue gas desulfurization (FGD) scrubber, given mercury (Hg) speciation at the FGD inlet, the flue gas composition, and the sulphur dioxide (SO2) capture efficiency. A preliminary statistical analysis of data from 17 full-scale wet FGDs connects flue gas compositions, the extents of Hg oxidation at FGD inlets, and Hg retention efficiencies. These connections clearly signal that solution chemistry within the FGD determines Hg retention. A more thorough analysis based on thermochemical equilibrium yields highly accurate predictions for total Hg retention with no parameter adjustments. For the most reliable data, the predictions were within measurement uncertainties for both limestone and Mg/lime systems operating in both forced and natural oxidation mode. With the U.S. Environmental Protection Agency's (EPA) Information Collection Request (ICR) database, the quantitative performance was almost as good for the most modern FGDs, which probably conform to the very high SO2 absorption efficiencies assumed in the calculations. The large discrepancies for older FGDs are tentatively attributed to the unspecified SO2 capture efficiencies and operating temperatures and to the possible elimination of HCl in prescrubbers. The equilibrium calculations suggest that Hg retention is most sensitive to inlet HCl and O2 levels and the FGD temperature; weakly dependent on SO2 capture efficiency; and insensitive to HgCl2, NO, CA:S ratio, slurry dilution level in limestone FGDs, and MgSO3 levels in Mg/lime systems. Consequently, systems with prescrubbers to eliminate HCl probably retain less Hg than fully integrated FGDs. The analysis also predicts re-emission of Hg(O) but only for inlet O2 levels that are much lower than those in full-scale FGDs.

Limestone weathering rates accelerated by micron-scale grain detachment

NASA Astrophysics Data System (ADS)

Emmanuel, S.; Levenson, Y.

2014-12-01

The weathering rates of carbonate rocks is often thought to be controlled by chemical dissolution, although some studies have suggested that mechanical erosion could also play an important role. Quantifying the rates of the different processes has proved challenging due to the high degree of variability encountered in both field and lab settings. To determine the rates and mechanisms controlling long-term limestone weathering, we analyse a lidar scan of the Western Wall, a Roman period edifice located in Jerusalem. Weathering rates in fine-grained micritic limestone blocks are up to 2 orders of magnitude higher than the average rates estimated for coarse-grained limestone blocks at the same site. In addition, in experiments that use atomic force microscopy to image dissolving micritic limestone, we show that these higher reaction rates could be due to rapid dissolution along micron-scale grain boundaries, followed by mechanical detachment of tiny particles from the surface. Our analysis indicates that micron-scale grain detachment, rather than pure chemical dissolution, could be the dominant erosional mode for fine-grained rocks in many carbonate terrains.

Extreme limestone weathering rates due to micron-scale grain detachment

NASA Astrophysics Data System (ADS)

Emmanuel, Simon; Levenson, Yael

2014-05-01

Chemical dissolution is often assumed to control the weathering rates of carbonate rocks, although some studies have indicated that mechanical erosion could also play a significant role. Quantifying the rates of the different processes is challenging due to the high degree of variability encountered in both field and lab settings. To measure the rates and mechanisms controlling long-term limestone weathering, we analyse a lidar scan of the Western Wall, a Roman period edifice located in Jerusalem. Surface retreat rates in fine-grained micritic limestone blocks are found to be as much as 2 orders of magnitude higher than the average rates estimated for coarse-grained limestone blocks at the same site. In addition, in experiments that use atomic force microscopy to image dissolving micritic limestone, we show that these elevated reaction rates could be due to rapid dissolution along micron-scale grain boundaries, followed by mechanical detachment of tiny particles from the surface. Our analysis indicates that micron-scale grain detachment, rather than pure chemical dissolution, could be the dominant erosional mode for fine-grained carbonate rocks.

Ignition and combustion characteristics of metallized propellants

NASA Technical Reports Server (NTRS)

Turns, Stephen R.; Mueller, D. C.

1993-01-01

Experimental and analytical investigations focusing on secondary atomization and ignition characteristics of aluminum/liquid hydrocarbon slurry propellants were conducted. Experimental efforts included the application of a laser-based, two-color, forward-scatter technique to simultaneously measure free-flying slurry droplet diameters and velocities for droplet diameters in the range of 10-200 microns. A multi-diffusion flame burner was used to create a high-temperature environment into which a dilute stream of slurry droplets could be introduced. Narrowband measurements of radiant emission were used to determine if ignition of the aluminum in the slurry droplet had occurred. Models of slurry droplet shell formation were applied to aluminum/liquid hydrocarbon propellants and used to ascertain the effects of solids loading and ultimate particle size on the minimum droplet diameter that will permit secondary atomization. For a 60 weight-percent Al slurry, the limiting critical diameter was predicted to be 34.7 microns which is somewhat greater than the 20-25 micron limiting diameters determined in the experiments. A previously developed model of aluminum ignition in a slurry droplet was applied to the present experiments and found to predict ignition times in reasonable agreement with experimental measurements. A model was also developed that predicts the mechanical stress in the droplet shell and a parametric study was conducted. A one-dimensional model of a slurry-fueled rocket combustion chamber was developed. This model includes the processes of liquid hydrocarbon burnout, secondary atomization, aluminum ignition, and aluminum combustion. Also included is a model for radiant heat transfer from the hot aluminum oxide particles to the chamber walls. Exercising this model shows that only a modest amount of secondary atomization is required to reduce residence times for aluminum burnout, and thereby maintain relatively short chamber lengths. The model also predicts radiant heat transfer losses to the walls to be only approximately 3 percent of the fuel energy supplied. Additional work is required to determine the effects of secondary atomization on two-phase losses in the nozzle.

A Preliminary Study of the Preparation of Slurry Fuels from Vaporized Magnesium

NASA Technical Reports Server (NTRS)

Witzke, Walter R; Prok, George M; Walsh, Thomas J

1954-01-01

Slurry fuels containing extremely small particles of magnesium were prepared by concentrating the dilute slurry product resulting from the shock-cooling of magnesium metal vapors with a liquid hydrocarbon spray. A complete description of the equipment and procedure used in preparing the fuel is given. Ninety-five percent by weight of the solid particles formed by this process passed through a 100-mesh screen. The particle-size distribution of the screened fraction of one run, as determined by sedimentation analysis, indicated that 73 percent by weight of the metal particles were finer than 2 microns in equivalent spherical diameter. The purity of the solid particles ranged as high as 98.9 percent by weight of free magnesium. The screened product was concentrated by means of a bowl-type centrifuge from 0.5 to more than 50 percent by weight solids content to form an extremely viscous, clay-like mass. By addition of a surface active agent, this viscous material was converted into a pumpable slurry fuel.

Process for gasifying carbonaceous material from a recycled condensate slurry

DOEpatents

Forney, Albert J.; Haynes, William P.

1981-01-01

Coal or other carbonaceous material is gasified by reaction with steam and oxygen in a manner to minimize the problems of effluent water stream disposal. The condensate water from the product gas is recycled to slurry the coal feed and the amount of additional water or steam added for cooling or heating is minimized and preferably kept to a level of about that required to react with the carbonaceous material in the gasification reaction. The gasification is performed in a pressurized fluidized bed with the coal fed in a water slurry and preheated or vaporized by indirect heat exchange contact with product gas and recycled steam. The carbonaceous material is conveyed in a gas-solid mixture from bottom to top of the pressurized fluidized bed gasifier with the solids removed from the product gas and recycled steam in a supported moving bed filter of the resulting carbonaceous char. Steam is condensed from the product gas and the condensate recycled to form a slurry with the feed coal carbonaceous particles.

Characterization of mixing and yield stress of pretreated wheat straw slurries used for the production of biofuels through tomography technique.

PubMed

Naghavi-Anaraki, Yasaman; Turcotte, Ginette; Ein-Mozaffari, Farhad

2018-05-29

Wheat straw is a low-cost feedstock for the production of biofuel. Pretreatment process is an important stage in producing biofuels since it makes the fibers more accessible to enzymatic hydrolysis which is the final step of producing biofuels. Pretreated wheat straw (PWS) slurries are non-Newtonian fluids with yield stress. Mixing of fluids exhibiting yield stress such as the pretreated wheat straw slurry results in the generation of cavern, which is a fully-mixed zone, around the impeller and the stationary regions elsewhere, which causes difficulties in the production of biofuels. In this study, the non-invasive electrical resistance tomography technique was utilized to determine the cavern dimensions as a function of the impeller type and impeller speed. The cavern sizes were then used to measure the yield stress of PWS slurries as a function of fiber size (≤ 2 and ≤ 6 mm) and fiber concentration (6, 8, and 10 wt%).

Groundwater sapping processes, Western Desert, Egypt.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, W.; Arvidson, R.E.; Sultan, M.

1997-01-01

Depressions of the Western Desert of Egypt (specifically, Kharga, Farafra, and Kurkur regions) are mainly occupied by shales that are impermeable, but easily erodible by rainfall and runoff, whereas the surrounding plateaus are composed of limestones that are permeable and more resistant to fluvial erosion under semiarid to arid conditions. Scallop-shaped escarpment edges and stubby-looking channels that cut into the plateau units are suggestive of slumping of limestones by ground-water sapping at the limestone-shale interfaces, removal of slump blocks by weathering and fluvial erosion, and consequent scarp retreat. Spring-derived tufa deposits found near the limestone escarpments provide additional evidence formore » possible ground-water sapping during previous wet periods. A computer simulation model was developed to quantify the ground-water sapping processes, using a cellular automata algorithm with coupled surface runoff and ground-water flow for a permeable, resistant layer over an impermeable, friable unit. Erosion, deposition, slumping, and generation of spring-derived tufas were parametrically modeled. Simulations using geologically reasonable parameters demonstrate that relatively rapid erosion of the shales by surface runoff, ground-water sapping, and slumping of the limestones, and detailed control by hydraulic conductivity inhomogeneities associated with structures explain the depressions, escarpments, and associated landforms and deposits. Using episodic wet pulses, keyed by {delta}{sup 18}O deep-sea core record, the model produced tufa ages that are statistically consistent with the observed U/Th tufa ages. This result supports the hypothesis that northeastern African wet periods occurred during interglacial maxima. The {delta}{sup 18}O-forced model also replicates the decrease in fluvial and sapping activity over the past million years, as northeastern Africa became hyperarid. The model thus provides a promising predictive tool for studying long-term landform evolution that involves surface and subsurface processes and climatic change.« less

Dentifrice fluoride and abrasivity interplay on artificial caries lesions.

PubMed

Nassar, Hani M; Lippert, Frank; Eckert, George J; Hara, Anderson T

2014-01-01

Incipient caries lesions on smooth surfaces may be subjected to toothbrushing, potentially leading to remineralization and/or abrasive wear. The interplay of dentifrice abrasivity and fluoride on this process is largely unknown and was investigated on three artificially created lesions with different mineral content/distribution. 120 bovine enamel specimens were randomly allocated to 12 groups (n = 10), resulting from the association of (1) lesion type [methylcellulose acid gel (MeC); carboxymethylcellulose solution (CMC); hydroxyethylcellulose gel (HEC)], (2) slurry abrasive level [low (REA 4/ RDA 69); high (REA 7/RDA 208)], and (3) fluoride concentration [0/275 ppm (14.5 mM) F as NaF]. After lesion creation, specimens were brushed in an automated brushing machine with the test slurries (50 strokes 2×/day). Specimens were kept in artificial saliva in between brushings and overnight. Enamel surface loss (SL) was determined by optical profilometry after lesion creation, 1, 3 and 5 days. Two enamel sections (from baseline and post-brushing areas) were obtained and analyzed microradiographically. Data were analyzed by analysis of variance and Tukey's tests (α = 5%). Brushing with high-abrasive slurry caused more SL than brushing with low-abrasive slurry. For MeC and CMC lesions, fluoride had a protective effect on SL from day 3 on. Furthermore, for MeC and CMC, there was a significant mineral gain in the remaining lesions except when brushed with high-abrasive slurries and 0 ppm F. For HEC, a significant mineral gain took place when low-abrasive slurry was used with fluoride. The tested lesions responded differently to the toothbrushing procedures. Both slurry fluoride content and abrasivity directly impacted SL and mineral gain of enamel caries lesions.

State of water in starch-water systems in the gelatinization temperature range as investigated using dielectric relaxation spectroscopy

NASA Astrophysics Data System (ADS)

Motwani, Tanuj

Starch-water interactions occurring during gelatinization are critical for developing a mechanistic understanding of the gelatinization process. The overall goal of this project was to investigate the state of water in starch-water systems in the gelatinization temperature range using dielectric relaxation spectroscopy. In the first part of the project, the dielectric response of native wheat starch-water slurries was measured at seven different starch concentrations between 5--60% starch (w/w) in the frequency range of 200 MHz--20 GHz at 25°C. The deconvolution of the dielectric spectra using the Debye model revealed presence of up to three relaxation processes. The relaxation time range of what were considered to be the high, intermediate and low frequency relaxations were 4--9 ps, 20--25 ps and 230--620 ps, respectively. The high frequency relaxation was observed at all starch concentrations, while the intermediate and low frequency relaxation were only observed at starch concentrations of 10% and above, and 30% and above, respectively. The high frequency relaxation was attributed to bulk water, while the intermediate and low frequency relaxations were attributed to rotationally restrained water molecules present in the starch-water system. To investigate the state of water in the gelatinization temperature range, the dielectric response, gelatinization enthalpy and water absorption by 10%, 30% or 50% starch slurries were measured after heating the slurries to different end temperatures between 40--90°C for 30 min. The high frequency relaxation time for 10% starch slurry dropped significantly (P<0.001) upon heating up to 60°C. For 30% and 50% starch slurries, high frequency relaxation times were not significantly influenced (P>0.159) by heating up to 80°C. The intermediate and low frequency relaxation times were not significantly influenced (P>0.712) by heating for all starch concentrations. Also, the amount of water associated with the three relaxations was not significantly influenced by heating (P >0.187). The water absorption results indicated that highest water uptake was achieved in the 10% starch slurry. The endothermic peak associated with gelatinization either vanished or was diminished after heating the slurries to 60°C and above, suggesting that native granular order was not necessary for the existence of the three separate states of water. In the second part of the project, the dielectric response of starch-water systems was investigated in the presence or absence of glucose or maltose. Dielectric response of 10% starch + 10% sugar, 10% starch + 20% sugar or 10% starch + 30% sugar slurries was measured in the frequency range of 200 MHz--20 GHz after heating the slurries to different end temperatures between 25--90°C for 30 min. The dielectric spectra of the slurries could be deconvoluted to obtain up to three Debye-type relaxations. The relaxation time range of high, intermediate and low frequency relaxations were 4--7 ps, 17--26 ps and 175--335 ps, respectively, at 25°C. The high frequency relaxation was the dominant relaxation in slurries containing 10% sugar, and the intermediate frequency relaxation was the dominant relaxation in slurries containing 30% sugar at 25°C. The high frequency relaxation time decreased upon heating up to 60°C but was not significantly influenced (P>0.102) by the concentration or the type of sugar. Intermediate and low frequency relaxation times were not significantly influenced (P>0.419) by heating or sugar type. The relative strengths of the intermediate frequency relaxation dropped while that of high frequency relaxation increased upon heating up to 50°C. The relative strength of low frequency relaxation (P>0.561) was not influenced by heating. The static dielectric constant decreased upon heating but was not influenced by the type of sugar or solids in the slurry. This indicated that the water molecules present in the system were the major contributors to the polarization observed. At the same concentration of solids, conductivity of the sugar containing slurries was lower than that of the non-sugar-containing starch slurries, which suggested that conductivity was mostly associated with starch. Glucose or maltose did not exert any differential effect on the swelling behavior or dielectric relaxation parameters of starch-water-sugar slurries. This project presents novel insights into the starch-water interactions occurring in the gelatinization temperature range. The results of this project can be used to develop a dielectric relaxation based technique to monitor water mobility during industrial processing of starch-based foods. Dielectric response was not unique to any of the solids used in the study suggesting that dielectric spectroscopy could be used for monitoring state of water in food systems containing different types of solids. Also, the dielectric relaxation parameters obtained in this study can be used to predict water mobility in simple food systems having water, sugar and starch as major components, and hence, can possibly be used to estimate shelf life of food products.

High-strength, creep-resistant molybdenum alloy and process for producing the same

DOEpatents

Bianco, R.; Buckman, R.W. Jr.; Geller, C.B.

1999-02-09

A wet-doping process for producing an oxide-dispersion strengthened (ODS), creep-resistant molybdenum alloy is disclosed. The alloy is made by adding nitrate or acetate salts of lanthanum, cerium, thorium, or yttrium to molybdenum oxide to produce a slurry, heating the slurry in a hydrogen atmosphere to produce a powder, mixing and cold isostatically pressing the powder, sintering in a hydrogen atmosphere, and thermomechanically processing (swaging, extruding, cold drawing) the product. The ODS molybdenum alloy produced by the process contains 2--4% by volume (ca. 1--4% by weight) of an oxide of lanthanum, cerium, thorium, or yttrium. The alloy has high strength and improved creep-resistance at temperatures greater than 0.55T{sub m} of molybdenum. 10 figs.

High-strength, creep-resistant molybdenum alloy and process for producing the same

DOEpatents

Bianco, Robert; Buckman, Jr., R. William; Geller, Clint B.

1999-01-01

A wet-doping process for producing an oxide-dispersion strengthened (ODS), creep-resistant molybdenum alloy is disclosed. The alloy is made by adding nitrate or acetate salts of lanthanum, cerium, thorium, or yttrium to molybdenum oxide to produce a slurry, heating the slurry in a hydrogen atmosphere to produce a powder, mixing and cold isostatically pressing the powder, sintering in a hydrogen atmosphere, and thermomechanically processing (swaging, extruding, cold drawing) the product. The ODS molybdenum alloy produced by the process contains 2-4% by volume (.about.1-4% by weight) of an oxide of lanthanum, cerium, thorium, or yttrium. The alloy has high strength and improved creep-resistance at temperatures greater than 0.55T.sub.m of molybdenum.

Attrition of limestone by impact loading in fluidized beds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fabrizio Scala; Fabio Montagnaro; Piero Salatino

2007-09-15

The present study addresses limestone attrition and fragmentation associated with impact loading, a process which may occur extensively in various regions of fluidized bed (FB) combustors/gasifiers, primarily the jetting region of the bottom bed, the exit region of the riser, and the cyclone. An experimental protocol for the characterization of the propensity of limestone to undergo attrition/fragmentation by impact loading is reported. The application of the protocol is demonstrated with reference to an Italian limestone whose primary fragmentation and attrition by surface wear have already been characterized in previous studies. The experimental procedure is based on the characterization of themore » amount and particle size distribution of the debris generated upon the impact of samples of sorbent particles against a target. Experiments were carried out at a range of particle impact velocities between 10 and 45 m/s, consistent with jet velocities corresponding to typical pressure drops across FB gas distributors. The protocol has been applied to either raw or preprocessed limestone samples. In particular, the effect of calcination, sulfation, and calcination/recarbonation cycles on the impact damage suffered by sorbent particles has been assessed. The measurement of particle voidage and pore size distribution by mercury intrusion was also accomplished to correlate fragmentation with the structural properties of the sorbent samples. Fragmentation by impact loading of the limestone is significant. Lime displays the largest propensity to undergo impact damage, followed by the sorbent sulfated to exhaustion, the recarbonated sorbent, and the raw limestone. Fragmentation of the raw limestone and of the sulfated lime follows a pattern typical of the failure of brittle materials. The fragmentation behavior of lime and recarbonated lime better conforms to a disintegration failure mode, with an extensive generation of very fine fragments. 27 refs., 9 figs. 1 tab.« less

Sequential capture of CO2 and SO2 in a pressurized TGA simulating FBC conditions.

PubMed

Sun, Ping; Grace, John R; Lim, C Jim; Anthony, Edward J

2007-04-15

Four FBC-based processes were investigated as possible means of sequentially capturing SO2 and CO2. Sorbent performance is the key to their technical feasibility. Two sorbents (a limestone and a dolomite) were tested in a pressurized thermogravimetric analyzer (PTGA). The sorbent behaviors were explained based on complex interaction between carbonation, sulfation, and direct sulfation. The best option involved using limestone or dolomite as a SO2-sorbent in a FBC combustor following cyclic CO2 capture. Highly sintered limestone is a good sorbent for SO2 because of the generation of macropores during calcination/carbonation cycling.

Performance and application of a fluidized bed limestone reactor designed for control of alkalinity, hardness and pH at the Warm Springs Regional Fisheries Center

USDA-ARS?s Scientific Manuscript database

Springs serving the Warm Springs Regional Fisheries Center, Warm Springs, Georgia, have pH, alkalinity, and hardness levels that lie under the range required for successful fish propagation while free CO2 is well above allowable targets. We evaluate a pretreatment process that exploits limestone's (...

Color machine vision in industrial process control: case limestone mine

NASA Astrophysics Data System (ADS)

Paernaenen, Pekka H. T.; Lemstrom, Guy F.; Koskinen, Seppo

1994-11-01

An optical sorter technology has been developed to improve profitability of a mine by using color line scan machine vision technology. The new technology adapted longers the expected life time of the limestone mine and improves its efficiency. Also the project has proved that color line scan technology of today can successfully be applied to industrial use in harsh environments.

Tunable integration of absorption-membrane-adsorption for efficiently separating low boiling gas mixtures near normal temperature

PubMed Central

Liu, Huang; Pan, Yong; Liu, Bei; Sun, Changyu; Guo, Ping; Gao, Xueteng; Yang, Lanying; Ma, Qinglan; Chen, Guangjin

2016-01-01

Separation of low boiling gas mixtures is widely concerned in process industries. Now their separations heavily rely upon energy-intensive cryogenic processes. Here, we report a pseudo-absorption process for separating low boiling gas mixtures near normal temperature. In this process, absorption-membrane-adsorption is integrated by suspending suitable porous ZIF material in suitable solvent and forming selectively permeable liquid membrane around ZIF particles. Green solvents like water and glycol were used to form ZIF-8 slurry and tune the permeability of liquid membrane surrounding ZIF-8 particles. We found glycol molecules form tighter membrane while water molecules form looser membrane because of the hydrophobicity of ZIF-8. When using mixing solvents composed of glycol and water, the permeability of liquid membrane becomes tunable. It is shown that ZIF-8/water slurry always manifests remarkable higher separation selectivity than solid ZIF-8 and it could be tuned to further enhance the capture of light hydrocarbons by adding suitable quantity of glycol to water. Because of its lower viscosity and higher sorption/desorption rate, tunable ZIF-8/water-glycol slurry could be readily used as liquid absorbent to separate different kinds of low boiling gas mixtures by applying a multistage separation process in one traditional absorption tower, especially for the capture of light hydrocarbons. PMID:26892255

Comparison and analysis of organic components of biogas slurry from eichhornia crassipes solms and corn straw biogas slurry

NASA Astrophysics Data System (ADS)

Li, Q.; Li, Y. B.; Liu, Z. H.; Min, J.; Cui, Y.; Gao, X. H.

2017-11-01

Biogas slurry is one of anaerobic fermentations, and biomass fermentation biogas slurries with different compositions are different. This paper mainly presents through the anaerobic fermentation of Eichhornia crassipes solms biogas slurry and biogas slurry of corn straw, the organic components of two kinds of biogas slurry after extraction were compared by TLC, HPLC and spectrophotometric determination of nucleic acid and protein of two kinds of biogas slurry organic components, and analyzes the result of comparison.

The nitrate to ammonia and ceramic (NAC) process for the denitration and immobilization of low-level radioactive liquid waste (LLW)

NASA Astrophysics Data System (ADS)

Muguercia, Ivan

Hazardous radioactive liquid waste is the legacy of more than 50 years of plutonium production associated with the United States' nuclear weapons program. It is estimated that more than 245,000 tons of nitrate wastes are stored at facilities such as the single-shell tanks (SST) at the Hanford Site in the state of Washington, and the Melton Valley storage tanks at Oak Ridge National Laboratory (ORNL) in Tennessee. In order to develop an innovative, new technology for the destruction and immobilization of nitrate-based radioactive liquid waste, the United State Department of Energy (DOE) initiated the research project which resulted in the technology known as the Nitrate to Ammonia and Ceramic (NAC) process. However, inasmuch as the nitrate anion is highly mobile and difficult to immobilize, especially in relatively porous cement-based grout which has been used to date as a method for the immobilization of liquid waste, it presents a major obstacle to environmental clean-up initiatives. Thus, in an effort to contribute to the existing body of knowledge and enhance the efficacy of the NAC process, this research involved the experimental measurement of the rheological and heat transfer behaviors of the NAC product slurry and the determination of the optimal operating parameters for the continuous NAC chemical reaction process. Test results indicate that the NAC product slurry exhibits a typical non-Newtonian flow behavior. Correlation equations for the slurry's rheological properties and heat transfer rate in a pipe flow have been developed; these should prove valuable in the design of a full-scale NAC processing plant. The 20-percent slurry exhibited a typical dilatant (shear thickening) behavior and was in the turbulent flow regime due to its lower viscosity. The 40-percent slurry exhibited a typical pseudoplastic (shear thinning) behavior and remained in the laminar flow regime throughout its experimental range. The reactions were found to be more efficient in the lower temperature range investigated. With respect to leachability, the experimental final NAC ceramic waste form is comparable to the final product of vitrification, the technology chosen by DOE to treat these wastes. As the NAC process has the potential of reducing the volume of nitrate-based radioactive liquid waste by as much as 70 percent, it not only promises to enhance environmental remediation efforts but also effect substantial cost savings.

Conceptualization of flow and transport in a limestone aquifer by multiple dedicated hydraulic and tracer tests

NASA Astrophysics Data System (ADS)

Mosthaf, Klaus; Brauns, Bentje; Fjordbøge, Annika S.; Rohde, Magnus M.; Kerrn-Jespersen, Henriette; Bjerg, Poul L.; Binning, Philip J.; Broholm, Mette M.

2018-06-01

Limestone aquifers are of great interest as a drinking water resource in many countries. They often have a complex crushed and fractured geology, which makes the analysis and description of flow and transport processes in such aquifers a challenging task. In this study, the solute transport behavior including fracture-matrix interaction in hydrogeological units of a limestone aquifer in eastern Denmark was characterized by designing, conducting and interpreting six depth-specific tracer tests involving natural- and forced-gradient conditions with multiple tracers representing different diffusion properties. To determine flow parameters, the tracer tests were complemented by a comprehensive set of depth-specific borehole and hydraulic tests. Based on the tests, a new and stronger conceptual understanding was developed for the different aquifer units. The investigated limestone aquifer is composed of a glacially crushed unit and two fractured units, with calcarenitic and bryozoan limestone of similar hydraulic properties. Hydraulic tests revealed that the crushed unit has a lower hydraulic conductivity than the fractured limestone units, likely due to the crushed conditions with small limestone clusters and small-aperture fractures potentially filled with fine material. In the fractured limestone units, a distinct preferential flow and primary transport along major horizontal fractures was inferred from the tracer tests under forced-gradient conditions. The dominant horizontal fractures were identified on impeller flow logs and appear connected between wells, having an extent of up to several hundred meters. Connectivity between the aquifer units was investigated with a long-term pumping test and tracer tests, revealing restricted vertical flow and transport. A very pronounced hydraulic conductivity contrast between major fractures and matrix could also be inferred from the borehole and hydraulic tests, which is consistent with the findings from the tracer tests. The difference in the matrix diffusion behavior of the simultaneously injected tracers and a long tailing in the breakthrough curves revealed that matrix diffusion has a strong influence on the solute transport in the fractured limestone.

Development of High-Speed Copper Chemical Mechanical Polishing Slurry for Through Silicon Via Application Based on Friction Analysis Using Atomic Force Microscope

NASA Astrophysics Data System (ADS)

Amanokura, Jin; Ono, Hiroshi; Hombo, Kyoko

2011-05-01

In order to obtain a high-speed copper chemical mechanical polishing (CMP) process for through silicon vias (TSV) application, we developed a new Cu CMP slurry through friction analysis of Cu reaction layer by an atomic force microscope (AFM) technique. A lateral modulation friction force microscope (LM-FFM) is able to measure the friction value properly giving a vibration to the layer. We evaluated the torsional displacement between the probe of the LM-FFM and the Cu reaction layer under a 5 nm vibration to cancel the shape effect of the Cu reaction layer. The developed Cu CMP slurry forms a frictionally easy-removable Cu reaction layer.

Assessment of kinetic models on Fe adsorption in groundwater using high-quality limestone

NASA Astrophysics Data System (ADS)

Akbar, N. A.; Kamil, N. A. F. Mohd; Zin, N. S. Md; Adlan, M. N.; Aziz, H. A.

2018-04-01

During the groundwater pumping process, dissolved Fe2+ is oxidized into Fe3+ and produce rust-coloured iron mineral. Adsorption kinetic models are used to evaluate the performance of limestone adsorbent and describe the mechanism of adsorption and the diffusion processes of Fe adsorption in groundwater. This work presents the best kinetic model of Fe adsorption, which was chosen based on a higher value of coefficient correlation, R2. A batch adsorption experiment was conducted for various contact times ranging from 0 to 135 minutes. From the results of the batch study, three kinetic models were analyzed for Fe removal onto limestone sorbent, including the pseudo-first order (PFO), pseudo-second order (PSO) and intra-particle diffusion (IPD) models. Results show that the adsorption kinetic models follow the sequence: PSO > PFO > IPD, where the values of R2 are 0.997 > 0.919 > 0.918. A high value of R2 (0.997) reveals better fitted experimental data. Furthermore, the value of qe cal in the PSO kinetic model is very near to qe exp rather than that in other models. This finding therefore suggests that the PSO kinetic model has the good fitted with the experimental data which involved chemisorption process of divalent Fe removal in groundwater solution. Thus, limestone adsorbent media found to be an alternative and effective treatment of Fe removal from groundwater.

Influence of the individual or combined application of biochar and slurry on soil macro-aggregate formation under varying moisture conditions

NASA Astrophysics Data System (ADS)

Kaiser, Michael; Grunwald, Dennis; Koch, Heinz-Josef; Rauber, Rolf; Ludwig, Bernard

2017-04-01

The formation of aggregates is of large importance for the structure and the storage of organic matter (OM) in soil. Although positive effects of organic soil additives on the formation of macro-aggregates (> 250 µm) have been reported, the influence of biochar especially applied in combination with other organic amendments remains unclear. Furthermore, studies on the effect of varying soil moisture conditions in form of drying-rewetting cycles on soil aggregate dynamics in the presence of biochar are almost missing. The objectives of this study were to analyze the effects of biochar and slurry applied to the soil individually or in combination on the formation of macro-aggregates under constant and under varying moisture conditions. We sampled four silty loam soils, carefully crushed the soil macro-aggregates, and incubated the soil at 15 °C for 60 days with the following additions: (i) none (control), (ii) biochar (12 % of dry soil mass), (iii) slurry (150 kg N ha-1), (iv) biochar (6 %) + slurry (75 kg N ha-1), (v) biochar (12 %) + slurry (75 kg N ha-1), (vi) biochar (6 %) + slurry (150 kg N ha-1) and (vii) biochar (12 %) + slurry (150 kg N ha-1). The samples were further subdivided into two groups that were incubated under conditions of constant soil moisture and of three drying-rewetting cycles. The CO2 fluxes were continuously measured during the incubation period and the samples were analyzed for microbial biomass C, macro-aggregate yields and macro-aggregate-associated C after finishing the experiment. We found the application of biochar to result in lower macro-aggregate yields with or without slurry compared to the control or the individual slurry application. In contrast, similar or higher C contents in the macro-aggregate fraction of the biochar treatments as compared to the control or slurry treatments were found indicating an occlusion of biochar in macro-aggregates. Due to the sorption characteristics of biochar, we assume the aggregate formation to be partially abiotic with direct interactions between biochar, (adsorbed) slurry, and the mineral phase of the soil. Therefore, in the presence of slurry, a prolonged period of microbial processing does not seem to be necessary to render the biochar suitable to form aggregates. Drying and rewetting of the samples resulted in significantly lower aggregate yields especially for the biochar/slurry mixtures. The drying of slurry as thought to be the most important macro-aggregate binding agent in these treatments might irreversibly disrupt large amounts of the macro-aggregates formed. Additionally, the general lower microbial biomass C and CO2 emissions for the samples experiencing drying-rewetting cycles compared to the constantly moist soils point toward less microbial activity under varying moisture conditions. This might have led to less microbial derived aggregate binding agents contributing to the lower aggregate yields found for the samples from the drying-rewetting treatments. Beside the amount and type of binding agents derived from organic soil additives, the formation and stability of soil macro-aggregate seem also to be controlled by climatically controlled soil moisture conditions.

HybridICE® filter: ice separation in freeze desalination of mine waste waters.

PubMed

Adeniyi, A; Maree, J P; Mbaya, R K K; Popoola, A P I; Mtombeni, T; Zvinowanda, C M

2014-01-01

Freeze desalination is an alternative method for the treatment of mine waste waters. HybridICE(®) technology is a freeze desalination process which generates ice slurry in surface scraper heat exchangers that use R404a as the primary refrigerant. Ice separation from the slurry takes place in the HybridICE filter, a cylindrical unit with a centrally mounted filter element. Principally, the filter module achieves separation of the ice through buoyancy force in a continuous process. The HybridICE filter is a new and economical means of separating ice from the slurry and requires no washing of ice with water. The performance of the filter at a flow-rate of 25 L/min was evaluated over time and with varied evaporating temperature of the refrigerant. Behaviours of the ice fraction and residence time were also investigated. The objective was to find ways to improve the performance of the filter. Results showed that filter performance can be improved by controlling the refrigerant evaporating temperature and eliminating overflow.

Rheology of corn stover slurries during fermentation to ethanol

NASA Astrophysics Data System (ADS)

Ghosh, Sanchari; Epps, Brenden; Lynd, Lee

2017-11-01

In typical processes that convert cellulosic biomass into ethanol fuel, solubilization of the biomass is carried out by saccharolytic enzymes; however, these enzymes require an expensive pretreatment step to make the biomass accessible for solubilization (and subsequent fermentation). We have proposed a potentially-less-expensive approach using the bacterium Clostridium thermocellum, which can initiate fermentation without pretreatment. Moreover, we have proposed a ``cotreatment'' process, in which fermentation and mechanical milling occur alternately so as to achieve the highest ethanol yield for the least milling energy input. In order to inform the energetic requirements of cotreatment, we experimentally characterized the rheological properties of corn stover slurries at various stages of fermentation. Results show that a corn stover slurry is a yield stress fluid, with shear thinning behavior well described by a power law model. Viscosity decreases dramatically upon fermentation, controlling for variables such as solids concentration and particle size distribution. To the authors' knowledge, this is the first study to characterize the changes in the physical properties of biomass during fermentation by a thermophilic bacterium.

Environmental process descriptors for TNT, TNT-related compounds and picric acid in marine sediment slurries.

PubMed

Yost, Sally L; Pennington, Judith C; Brannon, James M; Hayes, Charolett A

2007-08-01

Process descriptors were determined for picric acid, TNT, and the TNT-related compounds 2,4DNT, 2,6DNT, 2ADNT, 4ADNT, 2,4DANT, 2,6DANT, TNB and DNB in marine sediment slurries. Three marine sediments of various physical characteristics (particle size ranging from 15 to >90% fines and total organic carbon ranging from <0.10 to 3.60%) were kept in suspension with 20ppt saline water. Concentrations of TNT and its related compounds decreased immediately upon contact with the marine sediment slurries, with aqueous concentrations slowly declining throughout the remaining test period. Sediment-water partition coefficients could not be determined for these compounds since solution phase concentrations were unstable. Kinetic rates and half-lives were influenced by the sediment properties, with the finer grained, higher organic carbon sediment being the most reactive. Aqueous concentrations of picric acid were very stable, demonstrating little partitioning to the sediments. Degradation to picramic acid was minimal, exhibiting concentrations at or just above the detection limit.

Process for hydrocracking carbonaceous material in liquid carrier

DOEpatents

Duncan, Dennis A.

1980-01-01

Solid carbonaceous material is hydrocracked to provide aliphatic and aromatic hydrocarbons for use as gaseous and liquid fuels or chemical feed stock. Particulate carbonaceous material such as coal in slurry with recycled product oil is preheated in liquid state to a temperature of 600.degree.-1200.degree. F. in the presence of hydrogen gas. The product oil acts as a sorbing agent for the agglomerating bitumins to minimize caking within the process. In the hydrocracking reactor, the slurry of oil and carbonaceous particles is heated within a tubular passageway to vaporize the oil and form a gas-solid mixture which is further heated to a hydropyrolysis temperature in excess of 1200.degree. F. The gas-solid mixture is quenched by contact with additional oil to condense normally liquid hydrocarbons for separation from the gases. A fraction of the hydrocarbon liquid product is recycled for quenching and slurrying with the carbonaceous feed. Hydrogen is recovered from the gas for recycle and additional hydrogen is produced by gasification of residual char.

Numerical simulation of filtration of mine water from coal slurry particles

NASA Astrophysics Data System (ADS)

Dyachenko, E. N.; Dyachenko, N. N.

2017-11-01

The discrete element method is applied to model a technology for clarification of industrial waste water containing fine-dispersed solid impurities. The process is analyzed at the level of discrete particles and pores. The effect of filter porosity on the volume fraction of particles has been shown. The degree of clarification of mine water was also calculated depending on the coal slurry particle size, taking into account the adhesion force.

Microwave/Sonic Apparatus Measures Flow and Density in Pipe

NASA Technical Reports Server (NTRS)

Arndt, G. D.; Ngo, Phong; Carl, J. R.; Byerly, Kent A.

2004-01-01

An apparatus for measuring the rate of flow and the mass density of a liquid or slurry includes a special section of pipe instrumented with microwave and sonic sensors, and a computer that processes digitized readings taken by the sensors. The apparatus was conceived specifically for monitoring a flow of oil-well-drilling mud, but the basic principles of its design and operation are also applicable to monitoring flows of other liquids and slurries.

Corrosion protection

DOEpatents

Brown, Donald W.; Wagh, Arun S.

2003-05-27

There has been invented a chemically bonded phosphate corrosion protection material and process for application of the corrosion protection material for corrosion prevention. A slurry of iron oxide and phosphoric acid is used to contact a warm surface of iron, steel or other metal to be treated. In the presence of ferrous ions from the iron, steel or other metal, the slurry reacts to form iron phosphates which form grains chemically bonded onto the surface of the steel.

Method of waste stabilization via chemically bonded phosphate ceramics

DOEpatents

Wagh, Arun S.; Singh, Dileep; Jeong, Seung-Young

1998-01-01

A method for regulating the reaction temperature of a ceramic formulation process is provided comprising supplying a solution containing a monovalent alkali metal; mixing said solution with an oxide powder to create a binder; contacting said binder with bulk material to form a slurry; and allowing the slurry to cure. A highly crystalline waste form is also provided consisting of a binder containing potassium and waste substrate encapsulated by the binder.

Method of waste stabilization via chemically bonded phosphate ceramics

DOEpatents

Wagh, A.S.; Singh, D.; Jeong, S.Y.

1998-11-03

A method for regulating the reaction temperature of a ceramic formulation process is provided comprising supplying a solution containing a monovalent alkali metal; mixing said solution with an oxide powder to create a binder; contacting said binder with bulk material to form a slurry; and allowing the slurry to cure. A highly crystalline waste form is also provided consisting of a binder containing potassium and waste substrate encapsulated by the binder. 3 figs.

EXTERIOR VIEW, LOOKING EAST, OF REDUCTION PLANT NO. 6 WITH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

EXTERIOR VIEW, LOOKING EAST, OF REDUCTION PLANT NO. 6 WITH PRIMARY AND SECONDARY LIMESTONE REDUCTION ('CRUSHING') IN PROGRESS. FEEDER (RIGHT) FEEDS TO CONVEYOR BELTS (CENTER) AND CRUSHER (LEFT). LIMESTONE PROCESSED THROUGH THIS OPERATION IS FURTHER SCREENED AND PROCESSED AT ANOTHER PLANT ON THE THOMAS SITE. OPERATION OF THIS PLANT, WHICH BEGAN IN 1960, INCORPORATES WITHIN THE FEEDER A CONCRETE RETAINING WALL DATING TO A TURN OF THE CENTURY QUARRY OPERATION FORMERLY ON THIS SITE. - Wade Sand & Gravel Company, Reduction Plant No. 6, State Route 78, Thomas, Jefferson County, AL

Projections of Demand for Waterborne Transportation, Ohio River Basin, 1980, 1990, 2000, 2020, 2040. Volume 14. Group XII. Rubber, Plastic, Nonmetallic Mineral Products, Nec.

DTIC Science & Technology

1980-12-01

thousand tons by the year 2040. Much of this increased consumption will be lime used in flue gas desulfurization . A. Market Areas In addition to local...increased consumption will result from lime consumed in lime and limestone flue gas desulfur - ization (FGD) installation processes. During the period 2000...is the use of lime and limestone in flue gas desulfu- rization processes. Lime scrubbers for power plants and other industrial plants have also

Coal slurry fuel supply and purge system

DOEpatents

McDowell, Robert E.; Basic, Steven L.; Smith, Russel M.

1994-01-01

A coal slurry fuel supply and purge system for a locomotive engines is disclosed which includes a slurry recirculation path, a stand-by path for circulating slurry during idle or states of the engine when slurry fuel in not required by the engine, and an engine header fluid path connected to the stand-by path, for supplying and purging slurry fuel to and from fuel injectors. A controller controls the actuation of valves to facilitate supply and purge of slurry to and from the fuel injectors. A method for supplying and purging coal slurry in a compression ignition engine is disclosed which includes controlling fluid flow devices and valves in a plurality of fluid paths to facilitate continuous slurry recirculation and supply and purge of or slurry based on the operating state of the engine.

Comparative coal transportation costs: an economic and engineering analysis of truck, belt, rail, barge and coal slurry and pneumatic pipelines. Volume 3. Coal slurry pipelines. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rieber, M.; Soo, S.L.

1977-08-01

A coal slurry pipeline system requires that the coal go through a number of processing stages before it is used by the power plant. Once mined, the coal is delivered to a preparation plant where it is pulverized to sizes between 18 and 325 mesh and then suspended in about an equal weight of water. This 50-50 slurry mixture has a consistency approximating toothpaste. It is pushed through the pipeline via electric pumping stations 70 to 100 miles apart. Flow velocity through the line must be maintained within a narrow range. For example, if a 3.5 mph design is usedmore » at 5 mph, the system must be able to withstand double the horsepower, peak pressure, and wear. Minimum flowrate must be maintained to avoid particle settling and plugging. However, in general, once a pipeline system has been designed, because of economic considerations on the one hand and design limits on the other, flowrate is rather inflexible. Pipelines that have a slowly moving throughput and a water carrier may be subject to freezing in northern areas during periods of severe cold. One of the problems associated with slurry pipeline analyses is the lack of operating experience.« less

Zinc titanate sorbents

DOEpatents

Gupta, R.P.; Gangwal, S.K.; Jain, S.C.

1998-02-03

The present invention provides a zinc titanate sorbent material useful in desulfurization applications. The zinc titanate material is in the form of generally spherical particles of substantially uniform chemical distribution. The sorbent material is capable of absorbing sulfur compounds from a gaseous feed in an amount of at least about 15 weight percent based on the weight of the sorbent. The sorbent material is prepared by a process including: (a) forming a zinc oxide/titanium dioxide dry blend, (b) preparing a substantially uniform aqueous slurry comprising the zinc oxide/titanium dioxide dry blend, organic binder, and at least about 1 weight percent inorganic binder based on the solids weight of the slurry, (c) spray drying the slurry to produce substantially spherical particles, and (d) calcining the particles at a temperature of between about 750 to about 950 C. The dry blend is formed by mixing between about 0.5 to about 2 parts zinc oxide having a median particle size of less than about 0.5 microns, and about 1 part titanium dioxide having a median particle size of less than about 1 micron. The slurry contains substantially no free silica and may be prepared by the process including (1) preparing an aqueous solution of organic binder, (2) adding the dry blend to the aqueous solution of organic binder, and (3) adding the inorganic binder to the solution of organic binder, and blend. Additional reagents, such as a surfactant, may also be incorporated into the sorbent material. The present invention also provides a process for desulfurizing a gaseous stream. The process includes passing a gaseous stream through a reactor containing an attrition resistant zinc titanate sorbent material of the present invention.

Zinc titanate sorbents

DOEpatents

Gupta, Raghubir P.; Gangwal, Santosh K.; Jain, Suresh C.

1998-01-01

The present invention provides a zinc titanate sorbent material useful in desulfurization applications. The zinc titanate material is in the form of generally spherical particles of substantially uniform chemical distribution. The sorbent material is capable of absorbing sulfur compounds from a gaseous feed in an amount of at least about 15 weight percent based on the weight of the sorbent. The sorbent material is prepared by a process including: (a) forming a zinc oxide/titanium dioxide dry blend, (b) preparing a substantially uniform aqueous slurry comprising the zinc oxide/titanium dioxide dry blend, organic binder, and at least about 1 weight percent inorganic binder based on the solids weight of the slurry, (c) spray drying the slurry to produce substantially spherical particles, and (d) calcining the particles at a temperature of between about 750.degree. C. to about 950.degree. C. The dry blend is formed by mixing between about 0.5 to about 2 parts zinc oxide having a median particle size of less than about 0.5 .mu., and about 1 part titanium dioxide having a median particle size of less than about 1 .mu.. The slurry contains substantially no free silica and may be prepared by the process including (1) preparing an aqueous solution of organic binder, (2) adding the dry blend to the aqueous solution of organic binder, and (3) adding the inorganic binder to the solution of organic binder, and blend. Additional reagents, such as a surfactant, may also be incorporated into the sorbent material. The present invention also provides a process for desulfurizing a gaseous stream. The process includes passing a gaseous stream through a reactor containing an attrition resistant zinc titanate sorbent material of the present invention.

Impregnation of Composite Materials: a Numerical Study

NASA Astrophysics Data System (ADS)

Baché, Elliott; Dupleix-Couderc, Chloé; Arquis, Eric; Berdoyes, Isabelle

2017-12-01

Oxide ceramic matrix composites are currently being developed for aerospace applications such as the exhaust, where the parts are subject to moderately high temperatures (≈ 700 ∘C) and oxidation. These composite materials are normally formed by, among other steps, impregnating a ceramic fabric with a slurry of ceramic particles. This impregnation process can be complex, with voids possibly forming in the fabric depending on the process parameters and material properties. Unwanted voids or macroporosity within the fabric can decrease the mechanical properties of the parts. In order to design an efficient manufacturing process able to impregnate the fabric well, numerical simulations may be used to design the process as well as the slurry. In this context, a tool is created for modeling different processes. Thétis, which solves the Navier-Stokes-Darcy-Brinkman equation using finite volumes, is expanded to take into account capillary pressures on the mesoscale. This formulation allows for more representativity than for Darcy's law (homogeneous preform) simulations while avoiding the prohibitive simulation times of a full discretization for the composing fibers at the representative elementary volume scale. The resulting tool is first used to investigate the effect of varying the slurry parameters on impregnation evolution. Two different processes, open bath impregnation and wet lay-up, are then studied with emphasis on varying their input parameters (e.g. inlet velocity).

Multilayer ceramic oxide solid electrolyte for fuel cells and electrolysis cells and method for fabrication thereof

NASA Technical Reports Server (NTRS)

Schroeder, James E. (Inventor); Anderson, Harlan U. (Inventor)

1990-01-01

An unitary layered ceramic structure is disclosed which comprises co-sintered layers. The co-sintered structure comprises a sintered central layer of yttria stabilized zirconia (YSZ) which is about 8 mole percent yttria and having a density of at least about 95% of theoretical, and sintered outer layers of strontium lanthanum manganite (LSM) having the approximate molecular composition La.sub.0.8 Sr.sub.0.2 MnO.sub.3, having a density from about 50 to about 60% of theoretical, and having interconnected porosity from about 40 to 50% with an interconnected pore diameter from about one micron to about five microns. The sintered central layer is sandwiched by and bonded and sintered to the outer layers and is essentially free of significant amounts of manganese. A process for making the unitary composition-of-matter is also disclosed which involves tape casting a LSM tape and then on top thereof casting a YSZ tape. The process comprises presintering LSM powder at 1250.degree. F., crushing the presintered commercially available LSM powder, forming a slurry with the crushed LSM, a binder and solvent, tape casting the slurry and allowing the slurry to air dry. A mixture of commercially available submicron size particle YSZ powder is milled with a dispersant and solvent to disperse the YSZ particles thereby forming a dispersed YSZ slurry. The YSZ slurry is then tape cast on the dried LSM tape. If desired, a third layer of LSM can be cast on top of the dried YSZ layer. After drying the composite LSM/YSZ and LSM/YSZ/LSM tapes are fired at 1300.degree. C. No migration of manganese into the YSZ layer was observed with scanning electron microscope/edax in the sintered multilayer tape.

Multilayer ceramic oxide solid electrolyte for fuel cells and electrolysis cells

NASA Technical Reports Server (NTRS)

Schroeder, James E. (Inventor); Anderson, Harlan U. (Inventor)

1991-01-01

A unitary layered ceramic structure is disclosed which comprises co-sintered layers. The co-sintered structure comprises a sintered central layer of yttria stabilized zirconia (YSZ) which is about 8 mole percent yttria and having a density of at least about 95% of theoretical, and sintered outer layers of strontium lanthanum manganite (LSM) having the approximate molecular composition La.sub.0.8 Sr.sub.0.2 MnO.sub.3, having a density from about 50 to about 60% of theoretical, and having interconnected porosity from about 40 to 50% with an interconnected pore diameter from about one micron to about five microns. The sintered central layer is sandwiched by and bonded and sintered to the outer layers and is essentially free of significant amounts of manganese. A process for making the unitary composition-of-matter is also disclosed which involves tape casting a LSM tape and then on top thereof casting a YSZ tape. The process comprises presintering LSM powder at 1250.degree. F., crushing the presintered commercially available LSM powder, forming a slurry with the crushed LSM, a binder and solvent, tape casting the slurry and allowing the slurry to air dry. A mixture of commercially available submicron size particle YSZ powder is milled with a dispersant and solvent to disperse the YSZ particles thereby forming a dispersed YSZ slurry. The YSZ slurry is then tape cast on the dried LSM tape. If desired, a third layer of LSM can be cast on top of the dried YSZ layer. After drying the composite LSM/YSZ and LSM/YSZ/LSM tapes are fired at 1300.degree. C. No migration of manganese into the YSZ layer was observed with scanning electron microscope/edax in the sintered multilayer tape.

Full-scale results for TAM limestone injection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baer, S.

1996-12-31

Information is outlined on the use of thermally active marble (TAM) sorbents in boilers. Data are presented on: the comparison of TAM to limestone; NOVACON process development history; CFB test history; CFB pilot scale test; full-scale CFB trial; August, 1996 CFB demonstration; Foster Wheeler Mount Carmel sorbent feed rate comparison and Ca:S comparison; unburned carbon is ash; and advantages and savings in CFB boilers.

System and method for slurry handling

DOEpatents

Steele, Raymond Douglas; Oppenheim, Judith Pauline

2015-12-29

A system includes a slurry depressurizing system that includes a liquid expansion system configured to continuously receive a slurry at a first pressure and continuously discharge the slurry at a second pressure. For example, the slurry depressurizing system may include an expansion turbine to expand the slurry from the first pressure to the second pressure.

Colloidal and electrochemical aspects of copper-CMP

NASA Astrophysics Data System (ADS)

Sun, Yuxia

Copper based interconnects with low dielectric constant layers are currently used to increase interconnect densities and reduce interconnect time delays in integrated circuits. The technology used to develop copper interconnects involves Chemical Mechanical Planarization (CMP) of copper films deposited on low-k layers (silica or silica based films), which is carried out using slurries containing abrasive particles. One issue using such a structure is copper contamination over dielectric layers (SiO2 film), if not reduced, this contamination will cause current leakage. In this study, the conditions conducive to copper contamination onto SiO2 films during Cu-CMP process were studied, and a post-CMP cleaning technique was discussed based on experimental results. It was found that the adsorption of copper onto a silica surface is kinetically fast (<0.5 minute). The amount of copper absorbed is pH and concentration dependent and affected by presence of H2O2, complexing agents, and copper corrosion inhibitor Benzotrazole. Based on de-sorption results, DI water alone was unable to reduce adsorbed copper to an acceptable level, especially for adsorption that takes place at a higher pH condition. The addition of complex agent, citric acid, proved effective in suppressing copper adsorption onto oxide silica during polishing or post-CMP cleaning by forming stable copper-CA complexes. Surface Complexation Modeling was used to simulate copper adsorption isotherms and predict the copper contamination levels on SiO2 surfaces. Another issue with the application of copper CMP is its environmental impact. CMP is a costly process due to its huge consumption of pure water and slurry. Additionally, Cu-CMP processing generates a waste stream containing certain amounts of copper and abrasive slurry particles. In this study, the separation technique electrocoagulation was investigated to remove both copper and abrasive slurry particles simultaneously. For effluent containing ˜40 ppm dissolved copper, it was found that ˜90% dissolved copper was removed from the waste streams through electroplating and in-situ chemical precipitation. The amount of copper removed through plating is impacted by membrane surface charge, type/amount of complexing agents, and solid content in the slurry suspension. The slurry particles can be removed ˜90% within 2 hours of EC through multiple mechanisms.

Effect of Hydraulic Activity on Crystallization of Precipitated Calcium Carbonate (PCC) for Eco-Friendly Paper

PubMed Central

Kim, Jung-Ah; Han, Gi-Chun; Lim, Mihee; You, Kwang-Suk; Ryu, Miyoung; Ahn, Ji-Whan; Fujita, Toyohisa; Kim, Hwan

2009-01-01

Wt% of aragonite, a CaCO3 polymorph, increased with higher hydraulic activity (°C) of limestone in precipitated calcium carbonate (PCC) from the lime-soda process (Ca(OH)2-NaOH-Na2CO3). Only calcite, the most stable polymorph, was crystallized at hydraulic activity under 10 °C, whereas aragonite also started to crystallize over 10 °C. The crystallization of PCC is more dependent on the hydraulic activity of limestone than CaO content, a factor commonly used to classify limestone ores according to quality. The results could be effectively applied to the determination of polymorphs in synthetic PCC for eco-friendly paper manufacture. PMID:20087470

Effect of hydraulic activity on crystallization of precipitated calcium carbonate (PCC) for eco-friendly paper.

PubMed

Kim, Jung-Ah; Han, Gi-Chun; Lim, Mihee; You, Kwang-Suk; Ryu, Miyoung; Ahn, Ji-Whan; Fujita, Toyohisa; Kim, Hwan

2009-11-11

Wt% of aragonite, a CaCO(3) polymorph, increased with higher hydraulic activity ( degrees C) of limestone in precipitated calcium carbonate (PCC) from the lime-soda process (Ca(OH)(2)-NaOH-Na(2)CO(3)). Only calcite, the most stable polymorph, was crystallized at hydraulic activity under 10 degrees C, whereas aragonite also started to crystallize over 10 degrees C. The crystallization of PCC is more dependent on the hydraulic activity of limestone than CaO content, a factor commonly used to classify limestone ores according to quality. The results could be effectively applied to the determination of polymorphs in synthetic PCC for eco-friendly paper manufacture.

Paleokarst processes in the Eocene limestones of the Pyramids Plateau, Giza, Egypt

NASA Astrophysics Data System (ADS)

El Aref, M. M.; Refai, E.

The Eocene limestones of the Pyramids plateau are characterized by landforms of stepped terraced escarpment and karst ridges with isolated hills. The carbonate country rocks are also dominated by minor surface, surface to subsurface and subsurface solution features associated with karst products. The systematic field observations eludicate the denudation trend of the minor solution features and suggest the origin of the regional landscapes. The lithologic and structural characters of the limestone country rocks comprise the main factors controlling the surface and subsurface karst evolution. The development of the karst features and the associated sediments in the study area provides information on the paleohydrolic, chemical and climatic environments involved in the origin of the karstification.

Method and apparatus for in-situ drying investigation and optimization of slurry drying methodology

DOEpatents

Armstrong, Beth L.; Daniel, Claus; Howe, Jane Y.; Kiggans, Jr, James O.; Sabau, Adrian S.; Wood, III, David L.; Kalnaus, Sergiy

2016-05-10

A method of drying casted slurries that includes calculating drying conditions from an experimental model for a cast slurry and forming a cast film. An infrared heating probe is positioned on one side of the casted slurry and a thermal probe is positioned on an opposing side of the casted slurry. The infrared heating probe may control the temperature of the casted slurry during drying. The casted slurry may be observed with an optical microscope, while applying the drying conditions from the experimental model. Observing the casted slurry includes detecting the incidence of micro-structural changes in the casted slurry during drying to determine if the drying conditions from the experimental model are optimal.

Phosphorus recovery from biogas slurry by ultrasound/H2O2 digestion coupled with HFO/biochar adsorption process.

PubMed

He, Xuemeng; Zhang, Tao; Ren, Hongqiang; Li, Guoxue; Ding, Lili; Pawlowski, Lucjan

2017-02-01

Phosphorus (P) recovery from biogas slurry has recently attracted considerable interest. In this work, ultrasound/H 2 O 2 digestion coupled with ferric oxide hydrate/biochar (HFO/biochar) adsorption process was performed to promote P dissolution, release, and recovery from biogas slurry. The results showed that the optimal total phosphorus release efficiency was achieved at an inorganic phosphorus/total phosphorus ratio of 95.0% at pH 4, 1mL of added H 2 O 2 , and ultrasonication for 30min. The P adsorption by the HFO/biochar followed pseudo second-order kinetics and was mainly controlled by chemical processes. The Langmuir-Freundlich model matched the experimental data best for P adsorption by HFO/biochar at 298 and 308K, whereas the Freundlich model matched best at 318K. The maximum amount of P adsorbed was 220mg/g. The process was endothermic, spontaneous, and showed an increase in disorder at the solid-liquid interface. The saturated adsorbed HFO/biochar continually releases P and is most suitable for use in an alkaline environment. The amount of P released reached 29.1mg/g after five extractions. P mass balance calculation revealed that 11.3% of the total P can be made available. Copyright © 2016. Published by Elsevier Ltd.

Process for the solvent extraction for the radiolysis and dehalogenation of halogenated organic compounds in soils, sludges, sediments and slurries

DOEpatents

Golden, Jeffry

2007-02-13

A process of extracting halogenated organic compounds, and particularly PCBs, from soil, sediment, slurry, sludge and dehalogenating the compounds contacts a contaminated soil sample with an extraction medium of a mixture of an alkane and a water miscible alcohol. The organic compounds dissolve in the extraction medium which is separated from the soil by passing water upwardly through the soil. The extraction medium floats to the surface of the water and is separated. Thereafter, the extraction medium containing the halogenated organic contaminants is subjected to ionizing radiation to radiolytically dehalogenate the compounds.

Process for the solvent extraction for the radiolysis and dehalogenation of halogenated organic compounds in soils, sludges, sediments and slurries

DOEpatents

Mincher, Bruce J.; Curry, Randy Dale; Clevenger, Thomas E.; Golden, Jeffry

2003-05-27

A process of extracting halogenated organic compounds, and particularly PCBs, from soil, sediment, slurry, sludge and dehalogenating the compounds contacts a contaminated soil sample with an extraction medium of a mixture of an alkane and a water miscible alcohol. The organic compounds dissolve in the extraction medium which is separated from the soil by passing water upwardly through the soil. The extraction medium floats to the surface of the water and is separated. Thereafter, the extraction medium containing the halogenated organic contaminants is subjected to ionizing radiation to radiolytically dehalogenate the compounds.

Process for the solvent extraction for the radiolysis and dehalogenation of halogenated organic compounds in soils, sludges, sediments and slurries

DOEpatents

Mincher, Bruce J.; Curry, Randy Dale; Clevenger, Thomas E.; Golden, Jeffry

2000-01-01

A process of extracting halogenated organic compounds, and particularly PCBs, from soil, sediment, slurry, sludge and dehalogenating the compounds contacting a contaminated soil sample with an extraction medium of a mixture of an alkane and a water miscible alcohol. The organic compounds dissolve in the extraction medium which is separated from the soil by passing water upwardly through the soil. The extraction medium floats to the surface of the water and is separated. Thereafter, the extraction medium containing the halogenated organic contaminants is subjected to ionizing radiation to radiolytically dehalogenate the compounds.

Process for removal of hazardous air pollutants from coal

DOEpatents

Akers, David J.; Ekechukwu, Kenneth N.; Aluko, Mobolaji E.; Lebowitz, Howard E.

2000-01-01

An improved process for removing mercury and other trace elements from coal containing pyrite by forming a slurry of finely divided coal in a liquid solvent capable of forming ions or radicals having a tendency to react with constituents of pyrite or to attack the bond between pyrite and coal and/or to react with mercury to form mercury vapors, and heating the slurry in a closed container to a temperature of at least about 50.degree. C. to produce vapors of the solvent and withdrawing vapors including solvent and mercury-containing vapors from the closed container, then separating mercury from the vapors withdrawn.

Energy Saving Melting and Revert Reduction Technology: Innovative Semi-Solid Metal (SSM) Processing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diran Apelian

2012-08-15

Semi-solid metal (SSM) processing has emerged as an attractive method for near-net-shape manufacturing due to the distinct advantages it holds over conventional near-net-shape forming technologies. These advantages include lower cycle time, increased die life, reduced porosity, reduced solidification shrinkage, improved mechanical properties, etc. SSM processing techniques can not only produce the complex dimensional details (e.g. thin-walled sections) associated with conventional high-pressure die castings, but also can produce high integrity castings currently attainable only with squeeze and low-pressure permanent mold casting processes. There are two primary semi-solid processing routes, (a) thixocasting and (b) rheocasting. In the thixocasting route, one starts frommore » a non-dendritic solid precursor material that is specially prepared by a primary aluminum manufacturer, using continuous casting methods. Upon reheating this material into the mushy (a.k.a. "two-phase") zone, a thixotropic slurry is formed, which becomes the feed for the casting operation. In the rheocasting route (a.k.a. "slurry-on-demand" or "SoD"), one starts from the liquid state, and the thixotropic slurry is formed directly from the melt via careful thermal management of the system; the slurry is subsequently fed into the die cavity. Of these two routes, rheocasting is favored in that there is no premium added to the billet cost, and the scrap recycling issues are alleviated. The CRP (Trade Marked) is a process where the molten metal flows through a reactor prior to casting. The role of the reactor is to ensure that copious nucleation takes place and that the nuclei are well distributed throughout the system prior to entering the casting cavity. The CRP (Trade Marked) has been successfully applied in hyper-eutectic Al-Si alloys (i.e., 390 alloy) where two liquids of equal or different compositions and temperatures are mixed in the reactor and creating a SSM slurry. The process has been mostly used for hypo-eutectic Al-Si alloys (i.e., 356, 357, etc.) where a single melt passes through the reactor. In addition, the CRP (Trade Marked) was designed to be flexible for thixocasting or rheocasting applications as well as batch or continuous casting. Variable heat extraction rates can be obtained by controlling either the superheat of the melt, the temperature of the channel system, or the temperature of the reactor. This program had four main objectives all of which were focused on a mechanistic understanding of the process in order to be able to scale it up, to develop it into a robust process,and for SSM processing to be commercially used.« less

Method of making a functionally graded material

DOEpatents

Lauf, Robert J.; Menchhofer, Paul A.; Walls, Claudia A.

2001-01-01

A gelcasting method of making an internally graded article includes the steps of: preparing at least two slurries, each of the slurries including a different gelcastable powder suspended in a gelcasting solution, the slurries characterized by having comparable shrinkage upon drying and sintering thereof; casting the slurries into a mold having a selected shape, wherein relative proportions of the slurries is varied in at least one direction within the selected shape; gelling the slurries to form a solid gel while preserving the variation in relative proportions of the slurries; drying the gel to form a dried green body; and sintering the dry green body to form a solid object, at least one property thereof varying because of the variation in relative proportions of the starting slurries. A gelcasting method of making an internally graded article alternatively includes the steps of: preparing a slurry including a least two different phases suspended in a gelcasting solution, the phases characterized by having different settling characteristics; casting the slurry into a mold having a selected shape; allowing the slurry to stand for a sufficient period of time to permit desired gravitational fractionation in order to achieve a vertical compositional gradient in the molded slurry; gelling the slurry to form a solid gel while preserving the vertical compositional gradient in the molded slurry; drying the gel to form a dried green body; and sintering the dry green body to form a solid object, at least one property thereof varying along the vertical direction because of the compositional gradient in the molded slurry.

Rheological Characterization of Unusual DWPF Slurry Samples (U)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koopman, D. C.

2005-09-01

A study was undertaken to identify and clarify examples of unusual rheological behavior in Defense Waste Processing Facility (DWPF) simulant slurry samples. Identification was accomplished by reviewing sludge, Sludge Receipt and Adjustment Tank (SRAT) product, and Slurry Mix Evaporator (SME) product simulant rheological results from the prior year. Clarification of unusual rheological behavior was achieved by developing and implementing new measurement techniques. Development of these new methods is covered in a separate report, WSRC-TR-2004-00334. This report includes a review of recent literature on unusual rheological behavior, followed by a summary of the rheological measurement results obtained on a set ofmore » unusual simulant samples. Shifts in rheological behavior of slurries as the wt. % total solids changed have been observed in numerous systems. The main finding of the experimental work was that the various unusual DWPF simulant slurry samples exhibit some degree of time dependent behavior. When a given shear rate is applied to a sample, the apparent viscosity of the slurry changes with time rather than remaining constant. These unusual simulant samples are more rheologically complex than Newtonian liquids or more simple slurries, neither of which shows significant time dependence. The study concludes that the unusual rheological behavior that has been observed is being caused by time dependent rheological properties in the slurries being measured. Most of the changes are due to the effect of time under shear, but SB3 SME products were also changing properties while stored in sample bottles. The most likely source of this shear-related time dependence for sludge is in the simulant preparation. More than a single source of time dependence was inferred for the simulant SME product slurries based on the range of phenomena observed. Rheological property changes were observed on the time-scale of a single measurement (minutes) as well as on a time scale of hours to weeks. The unusual shape of the slurry flow curves was not an artifact of the rheometric measurement. Adjusting the user-specified parameters in the rheometer measurement jobs can alter the shape of the flow curve of these time dependent samples, but this was not causing the unusual behavior. Variations in the measurement parameters caused the time dependence of a given slurry to manifest at different rates. The premise of the controlled shear rate flow curve measurement is that the dynamic response of the sample to a change in shear rate is nearly instantaneous. When this is the case, the data can be fitted to a time independent rheological equation, such as the Bingham plastic model. In those cases where this does not happen, interpretation of the data is difficult. Fitting time dependent data to time independent rheological equations, such as the Bingham plastic model, is also not appropriate.« less

The Öland limestone - A Swedish stone used for more than one thousand years

NASA Astrophysics Data System (ADS)

Schouenborg, Björn; Wickström, Linda; Mikaelsson, Jan

2016-04-01

The second largest island in Sweden is the home of the "Öland limestone", a condensed and bedded limestone whose origin dates back to Lower Ordovician, i.e. about 480 M years ago. Öland is a part of the palaeocontinent Baltica that, at the time, was situated at low latitudes with deposition of the calcareous sediments in a cool water environment. The limestone on Öland represents a proximal ramp tectonic setting, with the oldest sediments deposited in the west and younger sediments deposited towards east and southeast. Fluctuating sea-levels have created erosional hard grounds such as the Flowery sheet. These hardgrounds are recognised by their vivid colours and trace fossils, and can be traced all over Baltica, but is maybe best represented on Öland. Ordovician limestones are present in many places in Sweden, but it is the occurrence on Öland that is the most renowned in a building stone perspective. One reason for this is the favourable trading location, an island off the Swedish East coast in middle of the trading routes between the Baltic countries and the continent. Other reasons are the pleasant aesthetical values with numerous orthoceratites and other fossils. The limestones on Öland differ in colour. From the red varieties (with oxidized iron) to brownish and grey. The bedding is mostly in the cm-scale which easily enables very exploitable thickness of slabs. Every mm limestone represents about 1000 years of deposition. The limestone has most likely been used in a very crude way for many thousand years, but archaeological evidence of a more industrialized usage is just a little more than 1000 years. It is known from the literature that the first official Swedish king, Gustav Vasa (16th century), desired this stone. At the time it was called "Öland marble", and the king "imported" specialists to process it further at the Royal Stone workshop on northern Öland. Remnants of tools and working sites still remain in an outdoor museum. Export of the Ölandic limestone was intense even during Hanseatic times (14th to 17th centuries) and it can for example be found as floorings, mantel pieces, baptismal fonts in many German castles and manors. The literature tells us that export to Denmark, Poland and even southern Germany was intense during late medieval ages. This is because a lot of churches were built in Northern Europe at that time. However, the modern industrialised production had to wait until the early 20th century. Today, three companies quarry and process the limestones on a regular basis. They are primarily used for flooring, stairs, crazy stones for gardens, table tops, kitchen tops and, in some cases, also external cladding and paving. The latter only with more durable layers free of clay and open stylolites, so called "core stone" (direct translation). The presentation will show that the Öland limestone covers all aspects and requirements for being a Global heritage resource.

The effect of diet manipulation on nitrous oxide and methane emissions from manure application to incubated grassland soils

NASA Astrophysics Data System (ADS)

Cardenas, L. M.; Chadwick, D.; Scholefield, D.; Fychan, R.; Marley, C. L.; Jones, R.; Bol, R.; Well, R.; Vallejo, A.

Changes to agricultural management, particularly of the nitrogen (N) input to farms, have great potential for mitigating emissions of N containing gases, especially the greenhouse gas nitrous oxide (N 2O). Manipulating diets fed to livestock is a potential method for controlling N excretion and emissions of greenhouse gases (GHG's) to the atmosphere. We selected three slurries derived from sheep that had been fed, either ensiled ryegrass ( Lolium hybridicum), lucerne ( Medicago sativa) or kale ( Brassica oleracea) and applied them to a grassland soil from the UK in a laboratory experiment using a special He/O 2 atmosphere incubation facility. The resulting fluxes of N 2O, CH 4 and N 2 were measured, with the largest total N fluxes generated by the ryegrass slurry treatment (14.23 ryegrass, 10.84 lucerne, 13.88 kale and 4.40 kg N ha -1 from the control). Methane was emitted only from the ryegrass slurry treatment. The isotopomer signatures for N 2O in the control and lucerne slurry treatments indicated that denitrification was the main process responsible for N 2O emissions.

The University of Arizona program in solid propellants

NASA Technical Reports Server (NTRS)

Ramohalli, Kumar

1989-01-01

The University of Arizona program is aimed at introducing scientific rigor to the predictability and quality assurance of composite solid propellants. Two separate approaches are followed: to use the modern analytical techniques to experimentally study carefully controlled propellant batches to discern trends in mixing, casting, and cure; and to examine a vast bank of data, that has fairly detailed information on the ingredients, processing, and rocket firing results. The experimental and analytical work is described briefly. The principle findings were that: (1) pre- (dry) blending of the coarse and fine ammonium perchlorate can significantly improve the uniformity of mixing; (2) the Fourier transformed IR spectra of the uncured and cured polymer have valuable data on the state of the fuel; (3) there are considerable non-uniformities in the propellant slurry composition near the solid surfaces (blades, walls) compared to the bulk slurry; and (4) in situ measurements of slurry viscosity continuously during mixing can give a good indication of the state of the slurry. Several important observations in the study of the data bank are discussed.

Biocapture of CO2 by Different Microalgal-Based Technologies for Biogas Upgrading and Simultaneous Biogas Slurry Purification under Various Light Intensities and Photoperiods

PubMed Central

Guo, Pengfei; Zhang, Yuejin; Zhao, Yongjun

2018-01-01

Co-cultivation of microalgae and microbes for pollutant removal from sewage is considered as an effective wastewater treatment method. The aim of this study is to screen the optimal photoperiod, light intensity and microalgae co-cultivation method for simultaneously removing nutrients in biogas slurry and capturing CO2 in biogas. The microalgae–fungi pellets are deemed to be a viable option because of their high specific growth rate and nutrient and CO2 removal efficiency under the photoperiod of 14 h light:10 h dark. The order of both the biogas slurry purification and biogas upgrading is ranked the same, that is Chlorella vulgaris–Ganoderma lucidum > Chlorella vulgaris–activated sludge > Chlorella vulgaris under different light intensities. For all cultivation methods, the moderate light intensity of 450 μmol m−2 s−1 is regarded as the best choice. This research revealed that the control of photoperiod and light intensity can promote the biological treatment process of biogas slurry purification and biogas upgrading using microalgal-based technology. PMID:29543784

Si Oxidation and H 2 Gassing During Aqueous Slurry Preparation for Li-Ion Battery Anodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hays, Kevin A.; Key, Baris; Li, Jianlin

Si has the possibility to greatly increase the energy density of Li-ion battery anodes, though it is not without its problems. One issue often overlooked is the decomposition of Si during large scale slurry formulation and battery fabrication. Here, we investigate the mechanism of H 2 production to understand the role of different slurry components and their impact on the Si oxidation and surface chemistry. Mass spectrometry and in situ pressure monitoring identifies that carbon black plays a major role in promoting the oxidation of Si and generation of H 2. Si oxidation also occurs through atmospheric O 2 consumption.more » Both pathways, along with solvent choice, impact the surface silanol chemistry, as analyzed by 1H– 29Si cross-polarization magic angle spinning nuclear magnetic resonance (MAS NMR) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR FTIR). An understanding of the oxidation of Si, during slurry processing, provides a pathway toward improving the manufacturing of Si based anodes by maximizing its capacity and minimizing safety hazards.« less

Superheated fuel injection for combustion of liquid-solid slurries

DOEpatents

Robben, Franklin A.

1985-01-01

A method and device for obtaining, upon injection, flash evaporation of a liquid in a slurry fuel to aid in ignition and combustion. The device is particularly beneficial for use of coal-water slurry fuels in internal combustion engines such as diesel engines and gas turbines, and in external combustion devices such as boilers and furnaces. The slurry fuel is heated under pressure to near critical temperature in an injector accumulator, where the pressure is sufficiently high to prevent boiling. After injection into a combustion chamber, the water temperature will be well above boiling point at a reduced pressure in the combustion chamber, and flash boiling will preferentially take place at solid-liquid surfaces, resulting in the shattering of water droplets and the subsequent separation of the water from coal particles. This prevents the agglomeration of the coal particles during the subsequent ignition and combustion process, and reduces the energy required to evaporate the water and to heat the coal particles to ignition temperature. The overall effect will be to accelerate the ignition and combustion rates, and to reduce the size of the ash particles formed from the coal.

Sinter of uniform, predictable, blemish-free nickel plaque for large aerospace nickel cadmium cells

NASA Technical Reports Server (NTRS)

Seiger, H. N.

1975-01-01

A series of nickel slurry compositions were tested. Important slurry parameters were found to be the nature of the binder, a pore former and the method of mixing. A slow roll mixing which is non-turbulent successfully eliminated entrapped air so that bubbles and pockets were avoided in the sinter. A slurry applicator was developed which enabled an equal quantity of slurry to be applied to both sides of the grid. Sintering in a furnace having a graded atmosphere characteristic, ranging from oxidizing to strongly reducing, improved adhesion of porous sinter to grid and resulted in a uniform welding of nickel particles to each other throughout the plaque. Sintering was carried out in a horizontal furnace having three heating zones and 16 heating control circuits. Tests used for plaque evaluation include (1) appearance, (2) grid location and adhesion, (3) mechanical strength, (4) thickness, (5) weight per unit area, (6) void volume per unit area, (7) surface area and (8) electrical resistance. Plaque material was impregnated using Heliotek proprietary processes and 100 AH cells were fabricated.

Si Oxidation and H 2 Gassing During Aqueous Slurry Preparation for Li-Ion Battery Anodes

DOE PAGES

Hays, Kevin A.; Key, Baris; Li, Jianlin; ...

2018-04-24

Si has the possibility to greatly increase the energy density of Li-ion battery anodes, though it is not without its problems. One issue often overlooked is the decomposition of Si during large scale slurry formulation and battery fabrication. Here, we investigate the mechanism of H 2 production to understand the role of different slurry components and their impact on the Si oxidation and surface chemistry. Mass spectrometry and in situ pressure monitoring identifies that carbon black plays a major role in promoting the oxidation of Si and generation of H 2. Si oxidation also occurs through atmospheric O 2 consumption.more » Both pathways, along with solvent choice, impact the surface silanol chemistry, as analyzed by 1H– 29Si cross-polarization magic angle spinning nuclear magnetic resonance (MAS NMR) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR FTIR). An understanding of the oxidation of Si, during slurry processing, provides a pathway toward improving the manufacturing of Si based anodes by maximizing its capacity and minimizing safety hazards.« less

Biocapture of CO₂ by Different Microalgal-Based Technologies for Biogas Upgrading and Simultaneous Biogas Slurry Purification under Various Light Intensities and Photoperiods.

PubMed

Guo, Pengfei; Zhang, Yuejin; Zhao, Yongjun

2018-03-15

Abstract : Co-cultivation of microalgae and microbes for pollutant removal from sewage is considered as an effective wastewater treatment method. The aim of this study is to screen the optimal photoperiod, light intensity and microalgae co-cultivation method for simultaneously removing nutrients in biogas slurry and capturing CO₂ in biogas. The microalgae-fungi pellets are deemed to be a viable option because of their high specific growth rate and nutrient and CO 2 removal efficiency under the photoperiod of 14 h light:10 h dark. The order of both the biogas slurry purification and biogas upgrading is ranked the same, that is Chlorella vulga ris - Ganoderma lucidum > Chlorella vulga ris -activated sludge > Chlorella vulgaris under different light intensities. For all cultivation methods, the moderate light intensity of 450 μmol m -2 s -1 is regarded as the best choice. This research revealed that the control of photoperiod and light intensity can promote the biological treatment process of biogas slurry purification and biogas upgrading using microalgal-based technology.

Approach for Configuring a Standardized Vessel for Processing Radioactive Waste Slurries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bamberger, Judith A.; Enderlin, Carl W.; Minette, Michael J.

2015-09-10

A standardized vessel design is being considered at the Waste Treatment and Immobilization Plant (WTP) that is under construction at Hanford, Washington. The standardized vessel design will be used for storing, blending, and chemical processing of slurries that exhibit a variable process feed including Newtonian to non-Newtonian rheologies over a range of solids loadings. Developing a standardized vessel is advantageous and reduces the testing required to evaluate the performance of the design. The objectives of this paper are to: 1) present a design strategy for developing a standard vessel mixing system design for the pretreatment portion of the waste treatmentmore » plant that must process rheologically and physically challenging process streams, 2) identify performance criteria that the design for the standard vessel must satisfy, 3) present parameters that are to be used for assessing the performance criteria, and 4) describe operation of the selected technology. Vessel design performance will be assessed for both Newtonian and non-Newtonian simulants which represent a range of waste types expected during operation. Desired conditions for the vessel operations are the ability to shear the slurry so that flammable gas does not accumulate within the vessel, that settled solids will be mobilized, that contents can be blended, and that contents can be transferred from the vessel. A strategy is presented for adjusting the vessel configuration to ensure that all these conditions are met.« less

Simulation of Hanford Tank 241-C-106 Waste Release into Tank 241-Y-102

DOE Office of Scientific and Technical Information (OSTI.GOV)

KP Recknagle; Y Onishi

Waste stored in Hdord single-shell Tank 241-C-106 will be sluiced with a supernatant liquid from doubIe-shell Tank 241 -AY- 102 (AY-1 02) at the U.S. Department of Energy's Har@ord Site in Eastern Washington. The resulting slurry, containing up to 30 wtYo solids, will then be transferred to Tank AY-102. During the sluicing process, it is important to know the mass of the solids being transferred into AY- 102. One of the primary instruments used to measure solids transfer is an E+ densitometer located near the periphery of the tank at riser 15S. This study was undert.dcen to assess how wellmore » a densitometer measurement could represent the total mass of soiids transferred if a uniform lateral distribution was assumed. The study evaluated the C-1 06 slurry mixing and accumulation in Tank AY- 102 for the following five cases: Case 1: 3 wt'%0 slurry in 6.4-m AY-102 waste Case 2: 3 w-t% slurry in 4.3-m AY-102 waste Case 3: 30 wtYo slurry in 6.4-m AY-102 waste Case 4: 30 wt% slurry in 4.3-m AY-102 waste Case 5: 30 wt% slurry in 5. O-m AY-102 waste. The tirne-dependent, three-dimensional, TEMPEST computer code was used to simulate solid deposition and accumulation during the injection of the C-106 slurry into AY-102 through four injection nozzles. The TEMPEST computer code was applied previously to other Hanford tanks, AP-102, SY-102, AZ-101, SY-101, AY-102, and C-106, to model tank waste mixing with rotating pump jets, gas rollover events, waste transfer from one tank to another, and pump-out retrieval of the sluiced waste. The model results indicate that the solid depth accumulated at the densitometer is within 5% of the average depth accumulation. Thus the reading of the densitometer is expected to represent the total mass of the transferred solids reasonably well.« less

Silver doped catalysts for treatment of exhaust

DOEpatents

Park, Paul Worn [Peoria, IL; Boyer, Carrie L [Shiloh, IL

2006-12-26

A method of making an exhaust treatment catalyst includes dispersing a metal-based material in a first solvent to form a first slurry and allowing polymerization of the first slurry to occur. Polymerization of the first slurry may be quenched and the first slurry may be allowed to harden into a solid. This solid may be redistributed in a second solvent to form a second slurry. The second slurry may be loaded with a silver-based material, and a silver-loaded powder may be formed from the second slurry.

The Lincolnshire Limestone — Hydrogeochemical evolution over a ten-year period

NASA Astrophysics Data System (ADS)

Edmunds, W. M.; Walton, N. R. G.

1983-02-01

In the Lincolnshire (Jurassic) Limestone of Britain, a sequence of hydrogeochemical processes along a 28-km flow line was defined in 1969. These processes include solution, redox and ion-exchange reactions, sulphate reduction and mixing with saline formation water. Resampling of the aquifer profile after 10 years has confirmed the overall sequence, although downgradient increases in both sulphate and calcium, together with changes in redox system, can be recognised. These changes are related to the migration of agrichemical pollutants and the results demonstrate that the aquifer must have a significant capacity for in situ nitrate reduction.

Elemental and mineralogical imaging of a weathered limestone rock by double-pulse micro-Laser-Induced Breakdown Spectroscopy

NASA Astrophysics Data System (ADS)

Senesi, Giorgio S.; Campanella, Beatrice; Grifoni, Emanuela; Legnaioli, Stefano; Lorenzetti, Giulia; Pagnotta, Stefano; Poggialini, Francesco; Palleschi, Vincenzo; De Pascale, Olga

2018-05-01

The present work aims to evaluate the alteration conditions of historical limestone rocks exposed to urban environment using the Laser-Induced Breakdown Spectroscopy (LIBS) technique. The approach proposed is based on the microscale three dimensional (3D) compositional imaging of the sample through double-pulse micro-Laser-Induced Breakdown Spectroscopy (DP-μLIBS) in conjunction with optical microscopy. DP-μLIBS allows to perform a quick and detailed in-depth analysis of the composition of the weathered artifact by creating a 'virtual thin section' (VTS) of the sample which can estimate the extent of the alteration processes occurred at the limestone surface. The DP-μLIBS analysis of these thin sections showed a reduction with depth of the elements (mainly Fe, Si and Na) originating from atmospheric dust, particulate deposition and the surrounding environment (due to the proximity of the sea), whereas, the LIBS signal of Ca increased in intensity from the black crust to the limestone underneath.

Limestone quarrying and quarry reclamation in Britain

NASA Astrophysics Data System (ADS)

Gunn, J.; Bailey, D.

1993-06-01

Limestones have been worked for many thousands of years — initially for building stone and agricultural lime and more recently for a wide range of construction and industrial uses. In most industrialized countries limestone quarries represent the most visually obvious and, in both process and landform terms, the most dramatic anthropogenic impact on karst terrain. However, quarrying has, to date, received surprisingly little attention from karst scientists. Research in the English Peak District suggested that the postexcavation evolution of quarried limestone rock faces was in part a result of the methods used in their excavation, and this led to the development of a technique designed to reduce the visual and environmental impacts of modern quarries by “Landform replication. ” This involves the use of controlled “restoration blasting” techniques on quarried rock slopes to construct a landform sequence similar to that in the surrounding natural landscape. The constructed landforms are then partially revegetated using appropriate wildflower, grass, and/or tree species.

Use Of limestone resources in flue-gas desulfurization power plants in the Ohio River Valley

USGS Publications Warehouse

Foose, M.P.; Barsotti, A.F.

1999-01-01

In 1994, more than 41 of the approximately 160 coal-fired, electrical- power plants within the six-state Ohio River Valley region used flue-gas desulfurization (FGD) units to desulfurize their emissions, an approximately 100% increase over the number of plants using FGD units in 1989. This increase represents a trend that may continue with greater efforts to meet Federal Clean Air Act standards. Abundant limestone resources exist in the Ohio River Valley and are accessed by approximately 975 quarries. However, only 35 of these are believed to have supplied limestone for FGD electrical generating facilities. The locations of these limestone suppliers do not show a simple spatial correlation with FGD facilities, and the closest quarries are not being used in most cases. Thus, reduction in transportation costs may be possible in some cases. Most waste generated by FGD electrical-generating plants is not recycled. However, many FGD sites are relatively close to gypsum wallboard producers that may be able to process some of their waste.

Coal recovery process

DOEpatents

Good, Robert J.; Badgujar, Mohan

1992-01-01

A method for the beneficiation of coal by selective agglomeration and the beneficiated coal product thereof is disclosed wherein coal, comprising impurities, is comminuted to a particle size sufficient to allow impurities contained therein to disperse in water, an aqueous slurry is formed with the comminuted coal particles, treated with a compound, such as a polysaccharide and/or disaccharide, to increase the relative hydrophilicity of hydrophilic components, and thereafter the slurry is treated with sufficient liquid agglomerant to form a coagulum comprising reduced impurity coal.

Method of making a hydrogen transport membrane, and article

DOEpatents

Schwartz, Joseph M.; Corpus, Joseph M.; Lim, Hankwon

2015-07-21

The present invention relates to a method of manufacturing a hydrogen transport membrane and the composite article itself. More specifically, the invention relates to producing a membrane substrate, wherein the ceramic substrate is coated with a metal oxide slurry, thereby eliminating the need for an activation step prior to plating the ceramic membrane through an electroless plating process. The invention also relates to modifying the pore size and porosity of the substrate by oxidation or reduction of the particles deposited by the metal oxide slurry.

Practical field repair of fused slurry silicide coating for space shuttle t.p.s.

NASA Technical Reports Server (NTRS)

Reznik, B. D.

1971-01-01

Study of short-time high-temperature diffusion treatments as part of a program of development of methods of reapplying fused slurry silicide coating in the field. The metallographic structure and oxidation behavior of R512E applied to Cb-752 coated under simulated field repair conditions was determined. Oxidation testing in reduced pressure environment has shown that performance equivalent to furnace-processed specimens can be obtained in a two-minute diffusion at 2700 F.

Ammonia volatilization from farm tanks containing anaerobically digested animal slurry

NASA Astrophysics Data System (ADS)

Sommer, S. G.

Ammonia (NH 3) volatilization from three full-scale tanks containing anaerobically digested animal slurry from one biogas plant was determined with a meteorological mass balance technique. No surface crust developed on the slurry. This provided an ideal system for analysing loss patterns from slurries without cover and to study the effect of a cover of straw and air-filled clay granules. Ammonia volatilization from uncovered slurry ranged from zero at subzero temperatures to 30 g N m -2 d -1 during summer. The high volatilization rate was attributed to a lack of surface cover, high slurry pH and high TAN (NH 3 + NH 4+) concentration. Ammonia volatilization from the covered slurry was insignificant. From the uncovered slurry the annual loss of NH3 was 3.3 kg N m -2 There was a significant effect of incident global radiation (ICR), air temperature at 20 cm (T_20) and rain on NH3 volatilization from the uncovered slurry. The straw covered slurry was significantly affected by T_20.

Laboratory study of SO2 dry deposition on limestone and marble: Effects of humidity and surface variables

USGS Publications Warehouse

Spiker, E. C.; Hosker, R.P.; Weintraub, V.C.; Sherwood, S.I.

1995-01-01

The dry deposition of gaseous air pollutants on stone and other materials is influenced by atmospheric processes and the chemical characteristics of the deposited gas species and of the specific receptor material. Previous studies have shown that relative humidity, surface moisture, and acid buffering capability of the receptor surface are very important factors. To better quantify this behavior, a special recirculating wind tunnel/environmental chamber was constructed, in which wind speed, turbulence, air temperature, relative humidity, and concentrations of several pollutants (SO2, O3, nitrogen oxides) can be held constant. An airfoil sample holder holds up to eight stone samples (3.8 cm in diameter and 1 cm thick) in nearly identical exposure conditions. SO2 deposition on limestone was found to increase exponentially with increasing relative humidity (RH). Marble behaves similarly, but with a much lower deposition rate. Trends indicate there is little deposition below 20% RH on clean limestone and below 60% RH on clean marble. This large difference is due to the limestone's greater porosity, surface roughness, and effective surface area. These results indicate surface variables generally limit SO2 deposition below about 70% RH on limestone and below at least 95% RH on marble. Aerodynamic variables generally limit deposition at higher relative humidity or when the surface is wet.The dry deposition of gaseous air pollutants on stone and other materials is influenced by atmospheric processes and the chemical characteristics of the deposited gas species and of the specific receptor material. Previous studies have shown that relative humidity, surface moisture, and acid buffering capability of the receptor surface are very important factors. To better quantify this behavior, a special recirculating wind tunnel/environmental chamber was constructed, in which wind speed, turbulence, air temperature, relative humidity, and concentrations of several pollutants (SO2, O3, nitrogen oxides) can be held constant. An airfoil sample holder holds up to eight stone samples (3.8 cm in diameter and 1 cm thick) in nearly identical exposure conditions. SO2 deposition on limestone was found to increase exponentially with increasing relative humidity (RH). Marble behaves similarly, but with a much lower deposition rate. Trends indicate there is little deposition below 20% RH on clean limestone and below 60% RH on clean marble. This large difference is due to the limestone's greater porosity, surface roughness, and effective surface area. These results indicate surface variables generally limit SO2 deposition below about 70% RH on limestone and below at least 95% RH on marble. Aerodynamic variables generally limit deposition at higher relative humidity or when the surface is wet.

BEHAVIOR OF MERCURY DURING DWPF CHEMICAL PROCESS CELL PROCESSING

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zamecnik, J.; Koopman, D.

2012-04-09

The Defense Waste Processing Facility has experienced significant issues with the stripping and recovery of mercury in the Chemical Processing Cell (CPC). The stripping rate has been inconsistent, often resulting in extended processing times to remove mercury to the required endpoint concentration. The recovery of mercury in the Mercury Water Wash Tank has never been high, and has decreased significantly since the Mercury Water Wash Tank was replaced after the seventh batch of Sludge Batch 5. Since this time, essentially no recovery of mercury has been seen. Pertinent literature was reviewed, previous lab-scale data on mercury stripping and recovery wasmore » examined, and new lab-scale CPC Sludge Receipt and Adjustment Tank (SRAT) runs were conducted. For previous lab-scale data, many of the runs with sufficient mercury recovery data were examined to determine what factors affect the stripping and recovery of mercury and to improve closure of the mercury material balance. Ten new lab-scale SRAT runs (HG runs) were performed to examine the effects of acid stoichiometry, sludge solids concentration, antifoam concentration, form of mercury added to simulant, presence of a SRAT heel, operation of the SRAT condenser at higher than prototypic temperature, varying noble metals from none to very high concentrations, and higher agitation rate. Data from simulant runs from SB6, SB7a, glycolic/formic, and the HG tests showed that a significant amount of Hg metal was found on the vessel bottom at the end of tests. Material balance closure improved from 12-71% to 48-93% when this segregated Hg was considered. The amount of Hg segregated as elemental Hg on the vessel bottom was 4-77% of the amount added. The highest recovery of mercury in the offgas system generally correlated with the highest retention of Hg in the slurry. Low retention in the slurry (high segregation on the vessel bottom) resulted in low recovery in the offgas system. High agitation rates appear to result in lower retention of mercury in the slurry. Both recovery of mercury in the offgas system and removal (segregation + recovery) from the slurry correlate with slurry consistency. Higher slurry consistency results in better retention of Hg in the slurry (less segregation) and better recovery in the offgas system, but the relationships of recovery and retention with consistency are sludge dependent. Some correlation with slurry yield stress and acid stoichiometry was also found. Better retention of mercury in the slurry results in better recovery in the offgas system because the mercury in the slurry is stripped more easily than the segregated mercury at the bottom of the vessel. Although better retention gives better recovery, the time to reach a particular slurry mercury content (wt%) is longer than if the retention is poorer because the segregation is faster. The segregation of mercury is generally a faster process than stripping. The stripping factor (mass of water evaporated per mass of mercury stripped) of mercury at the start of boiling were found to be less than 1000 compared to the assumed design basis value of 750 (the theoretical factor is 250). However, within two hours, this value increased to at least 2000 lb water per lb Hg. For runs with higher mercury recovery in the offgas system, the stripping factor remained around 2000, but runs with low recovery had stripping factors of 4000 to 40,000. DWPF data shows similar trends with the stripping factor value increasing during boiling. These high values correspond to high segregation and low retention of mercury in the sludge. The stripping factor for a pure Hg metal bead in water was found to be about 10,000 lb/lb. About 10-36% of the total Hg evaporated in a SRAT cycle was refluxed back to the SRAT during formic acid addition and boiling. Mercury is dissolved as a result of nitric acid formation from absorption of NO{sub x}. The actual solubility of dissolved mercury in the acidic condensate is about 100 times higher than the actual concentrations measured. Mercury metal present in the MWWT from previous batches could be dissolved by this acidic condensate. The test of the effect of higher SRAT condenser temperature on recovery of mercury in the MWWT and offgas system was inconclusive. The recovery at higher temperature was lower than several low temperature runs, but about the same as other runs. Factors other than temperature appear to affect the mercury recovery. The presence of chloride and iodide in simulants resulted in the formation of mercurous chloride and mercurous iodide, respectively, in the offgas system. Actual waste data shows that the chloride content is much less than the simulant concentrations. Future simulant tests should minimize the addition of chloride. Similarly, iodine addition should be eliminated unless actual waste analyses show it to be present; currently, total iodine is not measured on actual waste samples.« less

Sedimentology and paleoenvironments of the Las Chacritas carbonate paleolake, Cañadón Asfalto Formation (Jurassic), Patagonia, Argentina

NASA Astrophysics Data System (ADS)

Cabaleri, Nora G.; Benavente, Cecilia A.

2013-02-01

The Las Chacritas Member is the lower part of the Cañadón Asfalto Formation (Jurassic). The unit is a completely continental limestone succession with volcanic contributions that were deposited during the development of the Cañadón Asfalto Rift Basin (Chubut province, Patagonia, Argentina). A detailed sedimentological analysis was performed in the Fossati depocenter to determine the paleoenvironments that developed in the context of this rift. The Las Chacritas Member represents a carbonate paleolake system with ramp-shaped margins associated with wetlands that were eventually affected by subaerial exposure and pedogenesis. This process is represented by three main subenvironments: a) a lacustrine setting sensu stricto (lacustrine limestone facies association), represented by Mudstones/Wackestones containing porifera spicules (F1), Intraclastic packstones (F6) and Tabular stromatolites (F10) in which deposition and diagenesis were entirely subaqueous; b) a palustrine setting (palustrine limestone facies association) containing Microbial Mudstones (F2), Intraclastic sandy packstone with ostracode remains (F3), Oncolitic packstone (F5), Brecciated limestone (F7) and Nodular-Mottled limestone (F8) representing shallow marginal areas affected by groundwater fluctuations and minor subaerial exposure; and c) a pedogenic paleoenvironment (pedogenic limestone facies association) including Intraclastic limestone (F4) and Packstones containing Microcodium (F9) facies displaying the major features of subaerial exposure, pedogenic diagenesis and the development of paleosols. The fluvial-palustrine-lacustrine succession shows a general shallow upward trend in which contraction-expansion cycles are represented (delimited by exposure and surface erosion). The variations in the successive formations reflect the responses to fluctuations in a combination of two major controls, the tectonic and local climatic variables. The predominance of the palustrine facies associations was determined by its accommodation space as well as the local climate conditions. The variations in the lacustrine limestone facies associations reflect differential patterns of subsidence within the sub-basin. The diagnostic features of the palustrine limestone facies associations (organic matter (OM) content, microinvertebrate fauna, abundant mud cracks, brecciation, presence of evaporitic minerals) frame the sub-basin in a climatic context intermediate between arid and subhumid conditions.

Micronutrient component changes in the biogas slurry treated by a pilot solar-heated anaerobic reactor

NASA Astrophysics Data System (ADS)

Yang, Z. Y.; Xu, Y. B.; Li, P. F.; Wang, Y. J.; Sun, J.; Zhang, Y. P.

2017-06-01

A solar-heated anaerobic reactor system was applied to decompose livestock wastewater, in which cattle manure and chopped straw were mixed (CODCr 15,000∼25,000 mg·l-1), the commercial microorganisms were added to ambient acidification (about 32°C) and the acclimated sludge was inoculated. Then, the experiments were carried out on wastewater anaerobic degradation and biogas production at 40∼42°C, as fed every 10 days till stable running. The results showed that NH3-N and PO4 3- of the biogas slurry were 441 mg·l-1 and 65.0 mg·l-1 on the 35th day, respectively. The concentration of K was up to 350 mg·l-1 in the biogas slurry, rather higher than that of Mg and Fe, which indicated that the available K could contribute more in the agricultural irrigation. Total amino acids were up to 23.7 mg·l-1 after anaerobic digestion, in which Lys, Thr, Ala and Arg were prominent in the biogas slurry. These amino acids could be beneficial to seed soaking, feed adding and apply as foliar fertilizer. The major volatile organic compounds were detected in the biogas slurry, including toluene, m-cresol (up to 0.036% in the process of ambient acidification) and triethylsilane, which could be reduced to scarcely influence on agricultural application after anaerobic digestion.

Vinegar production from post-distillation slurry deriving from rice shochu production with the addition of caproic acid-producing bacteria consortium and lactic acid bacterium.

PubMed

Yuan, Hua-Wei; Tan, Li; Chen, Hao; Sun, Zhao-Yong; Tang, Yue-Qin; Kida, Kenji

2017-12-01

To establish a zero emission process, the post-distillation slurry of a new type of rice shochu (NTRS) was used for the production of health promoting vinegar. Since the NTRS post-distillation slurry contained caproic acid and lactic acid, the effect of these two organic acids on acetic acid fermentation was first evaluated. Based on these results, Acetobacter aceti CICC 21684 was selected as a suitable strain for subsequent production of vinegar. At the laboratory scale, acetic acid fermentation of the NTRS post-distillation slurry in batch mode resulted in an acetic acid concentration of 41.9 g/L, with an initial ethanol concentration of 40 g/L, and the acetic acid concentration was improved to 44.5 g/L in fed-batch mode. Compared to the NTRS post-distillation slurry, the vinegar product had higher concentrations of free amino acids and inhibition of angiotensin I converting enzyme activity. By controlling the volumetric oxygen transfer coefficient to be similar to that of the laboratory scale production, 45 g/L of acetic acid was obtained at the pilot scale, using a 75-L fermentor with a working volume of 40 L, indicating that vinegar production can be successfully scaled up. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Manifold Coal-Slurry Transport System

NASA Technical Reports Server (NTRS)

Liddle, S. G.; Estus, J. M.; Lavin, M. L.

1986-01-01

Feeding several slurry pipes into main pipeline reduces congestion in coal mines. System based on manifold concept: feeder pipelines from each working entry joined to main pipeline that carries coal slurry out of panel and onto surface. Manifold concept makes coal-slurry haulage much simpler than existing slurry systems.

Results of Hg speciation testing on DWPF SMECT-8, OGCT-1, AND OGCT-2 samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bannochie, C.

2016-02-22

The Savannah River National Laboratory (SRNL) was tasked with preparing and shipping samples for Hg speciation by Eurofins Frontier Global Sciences, Inc. in Seattle, WA on behalf of the Savannah River Remediation (SRR) Mercury Task Team. The sixteenth shipment of samples was designated to include a Defense Waste Processing Facility (DWPF) Slurry Mix Evaporator Condensate Tank (SMECT) sample from Sludge Receipt and Adjustment Tank (SRAT) Batch 738 processing and two Off-Gas Condensate Tank (OGCT) samples, one following Batch 736 and one following Batch 738. The DWPF sample designations for the three samples analyzed are provided. The Batch 738 ‘End ofmore » SME Cycle’ SMECT sample was taken at the conclusion of Slurry Mix Evaporator (SME) operations for this batch and represents the fourth SMECT sample examined from Batch 738. Batch 738 experienced a sludge slurry carryover event, which introduced sludge solids to the SMECT that were particularly evident in the SMECT-5 sample, but less evident in the ‘End of SME Cycle’ SMECT-8 sample.« less

An image processing approach for investigation on transport of iron oxide nanoparticles (FE3O4) stabilized with poly acrylic acid in two-dimensional porous media

NASA Astrophysics Data System (ADS)

Golzar, M.; Azhdary Moghaddam, M.; Saghravani, S. F.; Dahrazma, B.

2018-04-01

Iron oxide nanoparticles were stabilized using poly acrylic acid (PAA) to yield stabilized slurry of Iron oxide nanoparticles. A two-dimensional physical model filled by glass beads was used to study the fate and transport of the iron oxide nanoparticles stabilized with PAA in porous media under saturated, steady-state flow conditions. Transport data for a nonreactive tracer, slurry of iron oxide nanoparticles stabilized with PAA were collected under similar flow conditions. The results show that low concentration slurry of iron oxide nanoparticles stabilized with PAA can be transported like a tracer without significant retardation. The image processing technique was employed to measure the tracer/nanoparticle concentration inside the 2-D model filled with glass beads. The groundwater flow model, Visual MODFLOW, was used to model the observed transport patterns through MT3DMS module. Finally, it was demonstrated that the numerical model MODFLOW can be used to predict the fate and transport characteristics of nanoparticles stabilized with PAA in groundwater aquifers.

Comparison of the effects of different heat treatment processes on rheological properties of cake and bread wheat flours.

PubMed

Bucsella, Blanka; Takács, Ágnes; Vizer, Viktoria; Schwendener, Urs; Tömösközi, Sándor

2016-01-01

Dry and hydrothermal heat treatments are efficient for modifying the technological-functional and shelf-life properties of wheat milling products. Dry heat treatment process is commonly used to enhance the volume of cakes. Hydrothermal heat treatment makes wheat flours suitable as thickener agents. In this study, cake and bread wheat flours that differed in baking properties were exposed to dry (100 °C, 12 min) and hydrothermal (95 °C, 5 min, 5-20 l/h water) heat treatments. Rheological differences caused by the treatments were investigated in a diluted slurry and in a dough matrix. Dry heat treatment resulted in enhanced dough stability. This effect was significantly higher in the cake flour than the bread flour. Altered viscosity properties of the bread flour in the slurry matrix were also observed. The characteristics of hydrothermally treated samples showed matrix dependency: their viscosity increases in the slurry and decreases in the dough matrix. These results can support us to produce flour products with specific techno-functional properties. Copyright © 2015 Elsevier Ltd. All rights reserved.

Process for depositing hard coating in a nozzle orifice

DOEpatents

Flynn, P.L.; Giammarise, A.W.

1991-10-29

The present invention is directed to a process for coating the interior surfaces of an orifice in a substrate that forms a slurry fuel injection nozzle. In a specific embodiment, the nozzle is part of a fuel injection system for metering a coal-water slurry into a large, medium-speed, multi-cylinder diesel engine. In order to retard erosion of the orifice, the substrate is placed in a chemical vapor deposition (CVD) reaction chamber. A reaction gas is passed into the chamber at a gas temperature below its reaction temperature and is directed through the orifice in the substrate. The gas reaction temperature is a temperature at and above which the reaction gas deposits as a coating, and the reaction gas is of a composition whereby improved resistance to erosion by flow of the particulates in the slurry fuel is imparted by the deposited coating. Only the portion of the substrate in proximity to the orifice to be coated is selectively heated to at least the gas reaction temperature for effecting coating of the orifice's interior surfaces by the vapor deposited coating formed from the reaction gas. 2 figures.

Apparatus and process for depositing hard coating in a nozzle orifice

DOEpatents

Flynn, Paul L.; Giammarise, Anthony W.

1994-01-01

The present invention is directed to a process for coating the interior surfaces of an orifice in a substrate that forms a slurry fuel injection nozzle. In a specific embodiment, the nozzle is part of a fuel injection system for metering a coal-water slurry into a large, medium-speed, multi-cylinder diesel engine. In order to retard erosion of the orifice, the substrate is placed in a chemical vapor deposition (CVD) reaction chamber. A reaction gas is passed into the chamber at a gas temperature below its reaction temperature and is directed through the orifice in the substrate. The gas reaction temperature is a temperature at and above which the reaction gas deposits as a coating, and the reaction gas is of a composition whereby improved resistance to erosion by flow of the particulates in the slurry fuel is imparted by the deposited coating. Only the portion of the substrate in proximity to the orifice to be coated is selectively heated to at least the gas reaction temperature for effecting coating of the orifice's interior surfaces by the vapor deposited coating formed from the reaction gas.

Improved methods for the determination of drying conditions and fraction insoluble solids (FIS) in biomass pretreatment slurry

DOE PAGES

Sluiter, Amie; Sluiter, Justin; Wolfrum, Ed; ...

2016-05-20

Accurate and precise chemical characterization of biomass feedstocks and process intermediates is a requirement for successful technical and economic evaluation of biofuel conversion technologies. The uncertainty in primary measurements of the fraction insoluble solid (FIS) content of dilute acid pretreated corn stover slurry is the major contributor to uncertainty in yield calculations for enzymatic hydrolysis of cellulose to glucose. This uncertainty is propagated through process models and impacts modeled fuel costs. The challenge in measuring FIS is obtaining an accurate measurement of insoluble matter in the pretreated materials, while appropriately accounting for all biomass derived components. Three methods were testedmore » to improve this measurement. One used physical separation of liquid and solid phases, and two utilized direct determination of dry matter content in two fractions. We offer a comparison of drying methods. Lastly, our results show utilizing a microwave dryer to directly determine dry matter content is the optimal method for determining FIS, based on the low time requirements and the method optimization done using model slurries.« less

Process for depositing hard coating in a nozzle orifice

DOEpatents

Flynn, Paul L.; Giammarise, Anthony W.

1991-01-01

The present invention is directed to a process for coating the interior surfaces of an orifice in a substrate that forms a slurry fuel injection nozzle. In a specific embodiment, the nozzle is part of a fuel injection system for metering a coal-water slurry into a large, medium-speed, multi-cylinder diesel engine. In order to retard erosion of the orifice, the substrate is placed in a chemical vapor deposition (CVD) reaction chamber. A reaction gas is passed into the chamber at a gas temperature below its reaction temperature and is directed through the orifice in the substrate. The gas reaction temperature is a temperature at and above which the reaction gas deposits as a coating, and the reaction gas is of a composition whereby improved resistance toerosion by flow of the particulates in the slurry fuel is imparted by the deposited coating. Only the portion of the substrate in proximity to the orifice to be coated is selectively heated to at least the gas reaction temperature for effecting coating of the orifice's interior surfaces by the vapor deposited coating formed from the reaction gas.

Actual Waste Demonstration of the Nitric-Glycolic Flowsheet for Sludge Batch 9 Qualification

DOE Office of Scientific and Technical Information (OSTI.GOV)

J. D. Newell; Pareizs, J. M.; Martino, C. J.

For each sludge batch that is processed in the Defense Waste Processing Facility (DWPF), the Savannah River National Laboratory (SRNL) performs qualification testing to demonstrate that the sludge batch is processable. Testing performed by the Savannah River National Laboratory has shown glycolic acid to be effective in replacing the function of formic acid in the DWPF chemical process. The nitric-glycolic flowsheet reduces mercury, significantly lowers the catalytic generation of hydrogen and ammonia which could allow purge reduction in the Sludge Receipt and Adjustment Tank (SRAT), stabilizes the pH and chemistry in the SRAT and the Slurry Mix Evaporator (SME), allowsmore » for effective rheology adjustment, and is favorable with respect to melter flammability. In order to implement the new flowsheet, SRAT and SME cycles, designated SC-18, were performed using a Sludge Batch (SB) 9 slurry blended from SB8 Tank 40H and Tank 51H samples. The SRAT cycle involved adding nitric and glycolic acids to the sludge, refluxing to steam strip mercury, and dewatering to a targeted solids concentration. Data collected during the SRAT cycle included offgas analyses, process temperatures, heat transfer, and pH measurements. The SME cycle demonstrated the addition of glass frit and the replication of six canister decontamination additions. The demonstration concluded with dewatering to a targeted solids concentration. Data collected during the SME cycle included offgas analyses, process temperatures, heat transfer, and pH measurements. Slurry and condensate samples were collected for subsequent analysis« less

Slurry atomizer for a coal-feeder and dryer used to provide coal at gasifier pressure

DOEpatents

Loth, John L.; Smith, William C.; Friggens, Gary R.

1982-01-01

The present invention is directed to a coal-water slurry atomizer for use a high-pressure dryer employed in a pumping system utilized to feed coal into a pressurized coal gasifier. The slurry atomizer is provided with a venturi, constant area slurry injection conduit, and a plurality of tangentially disposed steam injection ports. Superheated steam is injected into the atomizer through these ports to provide a vortical flow of the steam, which, in turn, shears slurry emerging from the slurry injection conduit. The droplets of slurry are rapidly dispersed in the dryer through the venturi where the water is vaporized from the slurry by the steam prior to deleterious heating of the coal.

Characterization of microbial structures in Setul Limestone

NASA Astrophysics Data System (ADS)

Ezanie, A. S. Mohamad; Aziz, A. Che; Roslan, M. Kamal

2018-04-01

Setul Limestone in Langgun Island and Perlis are lack of sedimentary structures, which makes it difficult for paleoenvironmental study in the study area. The present study of limestone succession at Kaki Bukit and Teluk Mempelam area focuses on microbial related structure in order to constraint its depositional setting. The structures were identified as stromatolites and thrombolites, which resulted from the interaction of microbial with sediments by trapping, binding and/or precipitation of minerals. Both structures can be distinguished based on four main classifications, the megastructure, macrostructure, mesostructure and microstructure scales. These classifications assist in understanding its physical natures and lead to the recognition of paleoenvironment in the study area which is believed to be controlled by several factors such as environment, hydrodynamic, biological and chemical processes.

Evaluation of continuous oxydesulfurization processes. Final technical report, September 1979-July 1981

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, J.F.; Wever, D.M.

1981-07-01

Three processes developed by Pittsburgh Energy Technology Center (PETC), Ledgemont Laboratories, and Ames Laboratories for the oxydesulfurization of coal were evaluated in continuous processing equipment designed, built, and/or adapted for the purpose at the DOE-owned Multi-Use Fuels and Energy Processes Test Plant (MEP) located at TRW's Capistrano Test Site in California. The three processes differed primarily in the chemical additives (none, sodium carbonate, or ammonia), fed to the 20% to 40% coal/water slurries, and in the oxygen content of the feed gas stream. Temperature, pressure, residence time, flow rates, slurry concentration and stirrer speed were the other primary independent variables.more » The amount of organic sulfur removed, total sulfur removed and the Btu recovery were the primary dependent variables. Evaluation of the data presented was not part of the test effort.« less

Coal liquefaction process with enhanced process solvent

DOEpatents

Givens, Edwin N.; Kang, Dohee

1984-01-01

In an improved coal liquefaction process, including a critical solvent deashing stage, high value product recovery is improved and enhanced process-derived solvent is provided by recycling second separator underflow in the critical solvent deashing stage to the coal slurry mix, for inclusion in the process solvent pool.

FY13 GLYCOLIC-NITRIC ACID FLOWSHEET DEMONSTRATIONS OF THE DWPF CHEMICAL PROCESS CELL WITH SIMULANTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lambert, D.; Zamecnik, J.; Best, D.

Savannah River Remediation is evaluating changes to its current Defense Waste Processing Facility flowsheet to replace formic acid with glycolic acid in order to improve processing cycle times and decrease by approximately 100x the production of hydrogen, a potentially flammable gas. Higher throughput is needed in the Chemical Processing Cell since the installation of the bubblers into the melter has increased melt rate. Due to the significant maintenance required for the safety significant gas chromatographs and the potential for production of flammable quantities of hydrogen, eliminating the use of formic acid is highly desirable. Previous testing at the Savannah Rivermore » National Laboratory has shown that replacing formic acid with glycolic acid allows the reduction and removal of mercury without significant catalytic hydrogen generation. Five back-to-back Sludge Receipt and Adjustment Tank (SRAT) cycles and four back-to-back Slurry Mix Evaporator (SME) cycles were successful in demonstrating the viability of the nitric/glycolic acid flowsheet. The testing was completed in FY13 to determine the impact of process heels (approximately 25% of the material is left behind after transfers). In addition, back-to-back experiments might identify longer-term processing problems. The testing was designed to be prototypic by including sludge simulant, Actinide Removal Product simulant, nitric acid, glycolic acid, and Strip Effluent simulant containing Next Generation Solvent in the SRAT processing and SRAT product simulant, decontamination frit slurry, and process frit slurry in the SME processing. A heel was produced in the first cycle and each subsequent cycle utilized the remaining heel from the previous cycle. Lower SRAT purges were utilized due to the low hydrogen generation. Design basis addition rates and boilup rates were used so the processing time was shorter than current processing rates.« less

Method for inducing hypothermia

DOEpatents

Becker, Lance B.; Hoek, Terry Vanden; Kasza, Kenneth E.

2003-04-15

Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

Method for inducing hypothermia

DOEpatents

Becker, Lance B [Chicago, IL; Hoek, Terry Vanden [Chicago, IL; Kasza, Kenneth E [Palos Park, IL

2008-09-09

Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

Method for inducing hypothermia

DOEpatents

Becker, Lance B.; Hoek, Terry Vanden; Kasza, Kenneth E.

2005-11-08

Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

An Experimental Study on Slurry Erosion Resistance of Single and Multilayered Deposits of Ni-WC Produced by Laser-Based Powder Deposition Process

NASA Astrophysics Data System (ADS)

Balu, Prabu; Hamid, Syed; Kovacevic, Radovan

2013-11-01

Single and multilayered deposits containing different mass fractions of tungsten carbide (WC) in nickel (Ni)-matrix (NT-20, NT-60, NT-80) are deposited on a AISI 4140 steel substrate using a laser-based powder deposition process. The transverse cross section of the coupons reveals that the higher the mass fraction of WC in Ni-matrix leads to a more uniform distribution through Ni-matrix. The slurry erosion resistance of the fabricated coupons is tested at three different impingement angles using an abrasive water jet cutting machine, which is quantified based on the erosion rate. The top layer of a multilayered deposit (i.e., NT-60 in a two-layer NT-60 over NT-20 deposit) exhibits better erosion resistance at all three tested impingement angles when compared to a single-layer (NT-60) deposit. A definite increase in the erosion resistance is noted with an addition of nano-size WC particles. The relationship between the different mass fractions of reinforcement (WC) in the deposited composite material (Ni-WC) and their corresponding matrix (Ni) hardness on the erosion rate is studied. The eroded surface is analyzed in the light of a three-dimensional (3-D) profilometer and a scanning electron microscope (SEM). The results show that a volume fraction of approximately 62% of WC with a Ni-matrix hardness of 540 HV resulting in the gouging out of WC from the Ni-matrix by the action of slurry. It is concluded that the slurry erosion resistance of the AISI 4140 steel can be significantly enhanced by introducing single and multilayered deposits of Ni-WC composite material fabricated by the laser-based powder deposition process.

The impact of fouling on the process performance of the thermal treatment of pig slurry using tubular heat exchangers.

PubMed

Cunault, C; Burton, C H; Pourcher, A M

2013-03-15

The aim of this study was to determine the kinetics of fouling and their influence on the performance of a thermal treatment process used for sanitisation of pig slurry. Two temperatures (55 °C and 80 °C) were investigated. One trial was carried out at 55 °C and 80 °C in which the slurry was not re-circulated and one trial at 80 °C in which 100% or 50% of the slurry was re-circulated. Fouling of the heat exchangers was assessed by on-line monitoring of the drop in pressure, changes in treatment temperature, heat transfer coefficients, heat recycling rate, and energy consumption. Similar energy consumption of around 38 kWh m(-3) of effluent was observed at the two temperatures. The operating periods prior to excessive fouling or blockage were 18 days at 55 °C and four days at 80 °C. Recycling treated manure to obtain 50% dilution of the raw feed increased the viable operating period to 14 days at 80 °C but doubled energy consumption. At 55 °C, the significant drop in the target temperature (>7 °C) with fouling severely jeopardised the process. The nature of the decline in performance suggests that the main fouling mechanisms were bio-fouling at 55 °C and organic/mineral deposits at 80 °C. Recycling treated manure enabled the operating period to be extended but increased the total cost of heating. One hundred percent recycling showed that the fouling potential of the manure was largely eliminated after one thermal treatment, suggesting a pretreatment may be advantageous. Copyright © 2013 Elsevier Ltd. All rights reserved.

Hydrotectonics; principles and relevance

USGS Publications Warehouse

Kopf, R.W.

1982-01-01

Hydrotectonics combines the principles of hydraulics and rock mechanics. The hypothesis assumes that: (1) no faults are truly planar, (2) opposing noncongruent wavy wallrock surfaces form chambers and bottlenecks along the fault, and (3) most thrusting occurs beneath the water table. These physical constraints permit the following dynamics. Shear displacement accompanying faulting must constantly change the volume of each chamber. Addition of ground water liquefies dry fault breccia to a heavy incompressible viscous muddy breccia I call fault slurry. When the volume of a chamber along a thrust fault decreases faster than its fault slurry can escape laterally, overpressurized slurry is hydraulically injected into the base of near-vertical fractures in the otherwise impervious overriding plate. Breccia pipes commonly form where such fissures intersect. Alternating decrease and increase in volume of the chamber subjects this injection slurry to reversible surges that not only raft and abrade huge clasts sporadically spalled from the walls of the conduit but also act as a forceful hydraulic ram which periodically widens the conduit and extends its top. If the pipe perforates a petroleum reservoir, leaking hydrocarbons float to its top. Sudden faulting may generate a powerful water hammer that can be amplified at some distal narrow ends of the anastomosing plumbing system, where the shock may produce shatter cones. If vented on the Earth's surface, the muddy breccia, now called extrusion slurry, forms a mud volcano. This hypothesis suggests that many highly disturbed features presently attributed to such catastrophic processes as subsurface explosions or meteorite impacts are due to the rheology of tectonic slurry in an intermittently reactivated pressure-relief tube rooted in a powerful reciprocating hydrotectonic pump activated by a long-lived deep-seated thrust fault.

Conductivity and electrochemical performance of LiFePO4 slurry in the lithium slurry battery

NASA Astrophysics Data System (ADS)

Feng, Caimei; Chen, Yongchong; Liu, Dandan; Zhang, Ping

2017-06-01

Lithium slurry battery is a new type of energy storage technique which uses the slurry of solid active materials, conductive additions and liquid electrolyte as the electrode. The proportion of conductive addition and the active material has significant influence on the conductivity and electrochemical performance of the slurry electrode. In the present work, slurries with different volume ratios of LiFePO4 (LFP) and Ketjenblack (KB) were investigated by the electrochemical workstation and charge-discharge testing system (vs. Li/Li+). Results show that the conductivity of the slurry increases linearly with the addition of KB, and the measured specific capacity of the slurry reaches its theoretical value when the volume ratio of KB to LFP is around 0.2. Based on this ratio, a slurry battery with higher loading of LFP (19.1 wt.% in the slurry) was tested, and a specific capacity of 165 mAh/g at 0.2 mA/cm2 and 102 mAh/g at 5 mA/cm2 was obtained for LFP.

Water-assisted extrusion of bio-based PETG/clay nanocomposites

NASA Astrophysics Data System (ADS)

Lee, Naeun; Lee, Sangmook

2018-02-01

Bio-based polyethylene terephthalate glycol-modified (PETG)/clay nanocomposites were prepared using the water-assisted extrusion process. The effects of different types of clay and clay mixing methods (with or without the use of water) and the resulting nanocomposites properties were investigated by measuring the rheological and tensile properties and morphologies. The valuable properties were achieved when Cloisite 30B was mixed in a slurry state. The results of the X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies showed that the nano-clay was well dispersed within the PETG matrix. This shows that the slurry process could be an effective exfoliation method for many nanocomposites systems as well as for bio-based PETG/clay nanocomposites.

Effect of polishing process on corrosion behavior of 308L stainless steel in high temperature water

NASA Astrophysics Data System (ADS)

Ma, Cheng; Han, En-Hou; Peng, Qunjia; Ke, Wei

2018-06-01

Effect of change in surface composition and roughness by different polishing processes on corrosion of 308L stainless steel in high temperature water was investigated. The investigation was conducted by comparing the corrosion behavior of electropolished specimens with that of the 40 nm-colloidal silica slurry polished specimens. The result revealed that the electropolished specimens had a higher corrosion rate than the colloidal silica slurry polished specimens, which was attributed to formation of an amount of chromium hydroxide and higher roughness of the electropolished surface. Moreover, the ferrite in 308L stainless steel was found to have a higher resistance to corrosion than the austenite matrix.

Stratigraphy and depositional history of the West Franklin Limestone (Pennsylvanian) in the southernmost part of the Illinois Basin, western Kentucky

DOE Office of Scientific and Technical Information (OSTI.GOV)

King, N.R.

1994-04-01

The West Franklin Limestone in the subsurface of Webster and Union Counties, Kentucky includes 7.5--18m of strata deposited during portions of four depositional cycles in the latest Desmoinesian and earliest Missourian (Pennsylvanian). These cycles began with marine flooding and deposition of limestone, followed by progradation of siliciclastics in three of the four cycles, and ended with emergence. The basal West Franklin is micritic limestone (0.5--3m) that rests on rooted mudstone. Overlying the limestone are siliciclastics (1.5--7m) dominated by red and green claystone that is rooted at the top. Next is a middle limestone zone that includes either a paleokarsted micriticmore » limestone, or a thin bioclastic micritic limestone bed associated with phosphatic shale and locally a second bioclastic micritic limestone. Above that is another siliciclastic interval (4--9m) capped by rooted mudstone and locally a thin coal. The overlying micritic limestone (1.5--2.5m) marks the top of the West Franklin. Depositional events included: (1) marine flooding of an emergent shelf producing the basal limestone; (2) progradation of siliciclastics followed by emergence and paleosol development; (3) marine flooding producing a second limestone; (4) emergence and karstification of erosional remnants of the second limestone; (5) renewed marine flooding depositing shell hash'' limestones and phosphatic shale; (6) progradation of siliciclastics culminating in emergency; and (7) marine flooding producing the upper limestone. Thus, two flooding-emergence cycles are represented by the middle limestone zone. The second, locally-developed shell-hash'' limestone in the middle zone was deposited during the regressive phase of a depositional cycle. All of the other limestones were deposited during transgression.« less

Geology and evolution of lakes in north-central Florida

USGS Publications Warehouse

Kindinger, J.L.; Davis, J.B.; Flocks, J.G.

1999-01-01

Fluid exchange between surficial waters and groundwater in karst environments, and the processes that control exchange, are of critical concern to water management districts and planners. High-resolution seismic data were collected from 30 lakes of north-central Florida. In each case study, lake structure and geomorphology were controlled by solution and/or mechanical processes. Processes that control lake development are twofold: (1) karstification or dissolution of the underlying limestone, and (2) the collapse, subsidence, or slumping of overburden to form sinkholes. Initial lake formation is directly related to the karst topography of the underlying host limestone. Case studies have shown that lakes can be divided by geomorphic types into progressive developmental phases: (1) active subsidence or collapse phase (young); (2) transitional phase (middle age); (3) baselevel phase (mature); and (4) polje (drowned prairie) - broad flat-bottom that have one or all phases of sinkhole. Using these criteria, Florida lakes can be classified by size, fill, subsurface features, and geomorphology.Fluid exchange between surficial waters and groundwater in karst environments, and the processes that control exchange, are of critical concern to water management districts and planners. High-resolution seismic data were collected from 30 lakes of north-central Florida. In each case study, lake structure and geomorphology were controlled by solution and/or mechanical processes. Processes that control lake development are twofold: (1) karstification or dissolution of the underlying limestone, and (2) the collapse, subsidence, or slumping of overburden to form sinkholes. Initial lake formation is directly related to the karst topography of the underlying host limestone. Case studies have shown that lakes can be divided by geomorphic types into progressive developmental phased: (1) active subsidence or collapse phase (young); (2) transitional phase (middle age); (3) baselevel phase (mature); and (4) polje (drowned prairie) - broad flat-bottom that have one or all phases of sinkhole. Using these criteria, Florida lakes can be classified by size, fill, subsurface features, and geomorphology.

The Effect of Chemical Amendments Used for Phosphorus Abatement on Greenhouse Gas and Ammonia Emissions from Dairy Cattle Slurry: Synergies and Pollution Swapping.

PubMed

Brennan, Raymond B; Healy, Mark G; Fenton, Owen; Lanigan, Gary J

2015-01-01

Land application of cattle slurry can result in incidental and chronic phosphorus (P) loss to waterbodies, leading to eutrophication. Chemical amendment of slurry has been proposed as a management practice, allowing slurry nutrients to remain available to plants whilst mitigating P losses in runoff. The effectiveness of amendments is well understood but their impacts on other loss pathways (so-called 'pollution swapping' potential) and therefore the feasibility of using such amendments has not been examined to date. The aim of this laboratory scale study was to determine how the chemical amendment of slurry affects losses of NH3, CH4, N2O, and CO2. Alum, FeCl2, Polyaluminium chloride (PAC)- and biochar reduced NH3 emissions by 92, 54, 65 and 77% compared to the slurry control, while lime increased emissions by 114%. Cumulative N2O emissions of cattle slurry increased when amended with alum and FeCl2 by 202% and 154% compared to the slurry only treatment. Lime, PAC and biochar resulted in a reduction of 44, 29 and 63% in cumulative N2O loss compared to the slurry only treatment. Addition of amendments to slurry did not significantly affect soil CO2 release during the study while CH4 emissions followed a similar trend for all of the amended slurries applied, with an initial increase in losses followed by a rapid decrease for the duration of the study. All of the amendments examined reduced the initial peak in CH4 emissions compared to the slurry only treatment. There was no significant effect of slurry amendments on global warming potential (GWP) caused by slurry land application, with the exception of biochar. After considering pollution swapping in conjunction with amendment effectiveness, the amendments recommended for further field study are PAC, alum and lime. This study has also shown that biochar has potential to reduce GHG losses arising from slurry application.

The Effect of Chemical Amendments Used for Phosphorus Abatement on Greenhouse Gas and Ammonia Emissions from Dairy Cattle Slurry: Synergies and Pollution Swapping

PubMed Central

Brennan, Raymond B.; Healy, Mark G.; Fenton, Owen; Lanigan, Gary J.

2015-01-01

Land application of cattle slurry can result in incidental and chronic phosphorus (P) loss to waterbodies, leading to eutrophication. Chemical amendment of slurry has been proposed as a management practice, allowing slurry nutrients to remain available to plants whilst mitigating P losses in runoff. The effectiveness of amendments is well understood but their impacts on other loss pathways (so-called ‘pollution swapping’ potential) and therefore the feasibility of using such amendments has not been examined to date. The aim of this laboratory scale study was to determine how the chemical amendment of slurry affects losses of NH3, CH4, N2O, and CO2. Alum, FeCl2, Polyaluminium chloride (PAC)- and biochar reduced NH3 emissions by 92, 54, 65 and 77% compared to the slurry control, while lime increased emissions by 114%. Cumulative N2O emissions of cattle slurry increased when amended with alum and FeCl2 by 202% and 154% compared to the slurry only treatment. Lime, PAC and biochar resulted in a reduction of 44, 29 and 63% in cumulative N2O loss compared to the slurry only treatment. Addition of amendments to slurry did not significantly affect soil CO2 release during the study while CH4 emissions followed a similar trend for all of the amended slurries applied, with an initial increase in losses followed by a rapid decrease for the duration of the study. All of the amendments examined reduced the initial peak in CH4 emissions compared to the slurry only treatment. There was no significant effect of slurry amendments on global warming potential (GWP) caused by slurry land application, with the exception of biochar. After considering pollution swapping in conjunction with amendment effectiveness, the amendments recommended for further field study are PAC, alum and lime. This study has also shown that biochar has potential to reduce GHG losses arising from slurry application. PMID:26053923

A generalized genetic framework for the development of sinkholes and Karst in Florida, U.S.A.

NASA Astrophysics Data System (ADS)

Beck, Barry F.

1986-03-01

Karst topography in Florida is developed on the Tertiary limestones of the Floridan aquifer Post-depositional diagenesis and solution have made these limestones highly permeable, T=ca. 50,000 m2/d. Zones of megaporosity have formed at unconformities, and dissolution has enlarged joints and fractures Erosion of the overlying clastic Miocene Hawthorn group strata on one flank of a structural arch has exposed the limestone The elevated edge of the Hawthorn cover forms the Cody scarp Ubiquitous solution pipes have previously formed at joint intersections and are now filled Downwashing of the fill deeper into solution cavities in the limestone and subsidence of the overlying unconsolidated sediments causes surface collapse a subsidence doline or sinkhole This process may penetrate up to 60 m of the semi-consolidated Hawthorn cover, as occurred when the Winter Park sinkhole developed Dense clusters of solution pipes may have formed cenotes which are now found on the exposed limestone terrain Groundwater moves laterally as diffuse flow except where input or outflow is concentrated. At sinking streams, vertical shafts, and springs, karst caves have formed, but only the major sinking streams form through-flowing conduit systems Shaft recharge dissipates diffusely. Spring discharge is concentrated from diffuse flow In both cases, conduits taper and merge into a zone of megaporosity

Petrophysical and transport parameters evolution during acid percolation through structurally different limestones

NASA Astrophysics Data System (ADS)

Martinez Perez, Laura; Luquot, Linda

2017-04-01

Processes affecting geological media often show complex and unpredictable behavior due to the presence of heterogeneities. This remains problematic when facing contaminant transport problems, in the CO2 storage industry or dealing with the mechanisms underneath natural processes where chemical reactions can be observed during the percolation of rock non-equilibrated fluid (e.g. karst formation, seawater intrusion). To understand the mechanisms taking place in a porous medium as a result of this water-rock interaction, we need to know the flow parameters that control them, and how they evolve with time as a result of that concurrence. This is fundamental to ensure realistic predictions of the behavior of natural systems in response of reactive transport processes. We investigate the coupled influence of structural and hydrodynamic heterogeneities in limestone rock samples tracking its variations during chemical reactions. To do so we use laboratory petrophysical techniques such as helium porosimetry, gas permeability, centrifugue, electrical resistivity and sonic waves measurements to obtain the parameters that characterize flow within rock matrix (porosity, permeability, retention curve and pore size distribution, electrical conductivity, formation factor, cementation index and tortuosity) before and after percolation experiments. We built an experimental setup that allows injection of acid brine into core samples under well controlled conditions, monitor changes in hydrodynamic properties and obtain the chemical composition of the injected solution at different stages. 3D rock images were also acquired before and after the experiments using a micro-CT to locate the alteration processes and perform an acurate analysis of the structural changes. Two limestones with distinct textural classification and thus contrasting transport properties have been used in the laboratory experiments: a crinoid limestone and an oolithic limestone. Core samples dimensions were 1 inch in diameter and varied from 0.5 to 2 inches in length. Experiments were performed at room temperature, 8 bar of total pressure and 3 bar of PCO2. The acidic fluid has been injected at constant flow rate ranging from 0.4 mL/min to 6.7 mL/min depending of the rock typology and sample length. As expected, limestone dissolution occurred during the different percolation experiments, porosity and permeability augmented and sonic waves speed propagation decreased, showing an increase in the degree of heterogeneity of the rocks. The integration of all these parameters measured at different stages of dissolution provides contrasted and realistic geochemical, hydrodynamic and structural parameters to improve numerical simulations.

The differences between soil grouting with cement slurry and cement-water glass slurry

NASA Astrophysics Data System (ADS)

Zhu, Mingting; Sui, Haitong; Yang, Honglu

2018-01-01

Cement slurry and cement-water glass slurry are the most widely applied for soil grouting reinforcement project. The viscosity change of cement slurry is negligible during grouting period and presumed to be time-independent while the viscosity of cement-water glass slurry increases with time quickly and is presumed to be time-dependent. Due to the significantly rheology differences between them, the grouting quality and the increasing characteristics of grouting parameters may be different, such as grouting pressure, grouting surrounding rock pressure, i.e., the change of surrounding rock pressure deduced by grouting pressure. Those are main factors for grouting design. In this paper, a large-scale 3D grouting simulation device was developed to simulate the surrounding curtain grouting for a tunnel. Two series of surrounding curtain grouting experiments under different geo-stress of 100 kPa, 150 kPa and 200 kPa were performed. The overload test on tunnel was performed to evaluate grouting effect of all surrounding curtain grouting experiments. In the present results, before 240 seconds, the grouting pressure increases slowly for both slurries; after 240 seconds the increase rate of grouting pressure for cement-water glass slurry increases quickly while that for cement slurry remains roughly constant. The increasing trend of grouting pressure for cement-water glass is similar to its viscosity. The setting time of cement-water glass slurry obtained from laboratory test is less than that in practical grouting where grout slurry solidifies in soil. The grouting effect of cement-water glass slurry is better than that of cement slurry and the grouting quality decreases with initial pressure.

Recovery technologies for building materials

NASA Astrophysics Data System (ADS)

Karu, Veiko; Nurme, Martin; Valgma, Ingo

2015-04-01

Mining industry provides building materials for construction. Civil engineers have settled the quality parameters for construction materials. When we produce high quality building materials from carbonate rock (limestone, dolostone), then the estimated waste share is 25% to 30%, depending on crushing principles and rock quality. The challenge is to find suitable technology for waste recovery. During international mining waste related cooperation project MIN-NOVATION (www.min-novation.eu), partners mapped possibilities for waste recovery in mining industry and pointed out good examples and case studies. One example from Estonia showed that when we produce limestone aggregate, then we produce up to 30% waste material (fines with size 0-4mm). This waste material we can see as secondary raw material for building materials. Recovery technology for this fine grained material has been achieved with CDE separation plant. During the process the plant washes out minus 63 micron material from the limestone fines. This technology allows us to use 92% of all limestone reserves. By-product from 63 microns to 4 mm we can use as filler in concrete or as fine limestone aggregate for building or building materials. MIN-NOVATION project partners also established four pilot stations to study other mineral waste recovery technologies and solutions. Main aims on this research are to find the technology for recovery of mineral wastes and usage for new by-products from mineral mining waste. Before industrial production, testing period or case studies are needed. This research is part of the study of Sustainable and environmentally acceptable Oil shale mining No. 3.2.0501.11-0025 http://mi.ttu.ee/etp and the project B36 Extraction and processing of rock with selective methods - http://mi.ttu.ee/separation; http://mi.ttu.ee/miningwaste/

A study of iron mineral transformation to reduce red mud tailings.

PubMed

Li, L Y

2001-01-01

This study examines the effects of iron mineral transformation in an aluminum extraction process on the settling behavior, and the physical and chemical properties of the resulting red mud slurry that must be disposed of. By producing a red mud with a higher solid content, the total volume of mud slurry will also be reduced for a given alumina production rate and more caustic soda will be recovered. The settling behavior and the mineralogical, physical, and physico-chemical properties of one bauxite and three red muds processed under varying conditions were analyzed based on examination of the iron mineral transformations. The properties of red muds derived from the same bauxite can differ markedly due to variations in operating conditions of the Bayer process, such as temperature and the addition of a reducing agent. The settling of red mud can be improved by converting goethite into hematite and/or magnetite to produce a mud of larger particle size, smaller specific surface area, and larger specific gravity, characteristics which reduce the total volume of mud slurry to be disposed of and which allow for less potential contamination from caustic soda. This study also found that the by-product--Bayer sodalite--has the high exchange capacity for Na+ that might contribute to the long-term environmental problems.

Transport of Cryptosporidium parvum Oocysts in Soil Columns following Applications of Raw and Separated Liquid Slurries

PubMed Central

Petersen, Heidi H.; Enemark, Heidi L.; Olsen, Annette; Amin, M. G. Mostofa

2012-01-01

The potential for the transport of viable Cryptosporidium parvum oocysts through soil to land drains and groundwater was studied using simulated rainfall and intact soil columns which were applied raw slurry or separated liquid slurry. Following irrigation and weekly samplings over a 4-week period, C. parvum oocysts were detected from all soil columns regardless of slurry type and application method, although recovery rates were low (<1%). Soil columns with injected liquid slurry leached 73 and 90% more oocysts compared to columns with injected and surface-applied raw slurries, respectively. Among leachate samples containing oocysts, 44/72 samples yielded viable oocysts as determined by a dye permeability assay (DAPI [4′,6′-diamidino-2-phenylindole]/propidium iodide) with the majority (41%) of viable oocysts found in leachate from soil columns with added liquid slurry. The number of viable oocysts was positively correlated (r = 0.63) with the total number of oocysts found. Destructively sampling of the soil columns showed that type of slurry and irrigation played a role in the vertical distribution of oocysts, with more oocysts recovered from soil columns added liquid slurry irrespective of the irrigation status. Further studies are needed to determine the effectiveness of different slurry separation technologies to remove oocysts and other pathogens, as well as whether the application of separated liquid slurry to agricultural land may represent higher risks for groundwater contamination compared to application of raw slurry. PMID:22706058

Modified dry limestone process for control of sulfur dioxide emissions

DOEpatents

Shale, Correll C.; Cross, William G.

1976-08-24

A method and apparatus for removing sulfur oxides from flue gas comprise cooling and conditioning the hot flue gas to increase the degree of water vapor saturation prior to passage through a bed of substantially dry carbonate chips or lumps, e.g., crushed limestone. The reaction products form as a thick layer of sulfites and sulfates on the surface of the chips which is easily removed by agitation to restore the reactive surface of the chips.

Treatment of iron(II)-rich acid mine water with limestone and oxygen.

PubMed

Mohajane, G B; Maree, J P; Panichev, N

2014-01-01

The main components of acid mine water are free acid, sulphate, and Fe²⁺. Limestone is the most cost-effective alkali that can be used for neutralization. The purpose of this investigation was to identify conditions where Fe²⁺ is removed with limestone and simultaneously oxidized with oxygen to Fe³⁺, in a polyvinyl chloride pipe under pressure. Gypsum scaling is prevented by passing rubber balls through the pipe of the so-called Oxygen-Pipe-Neutralization (OPeN) process pilot plant. Two synthetic waters were treated: (A) acid mine water containing 123 mg L⁻¹ Fe²⁺ representing gold mine water, and (B) acid mine water containing 6,032 mg L⁻¹ Fe²⁺ representing coal mine water. Batch studies were carried out in a pipe reactor and showed that the rate of Fe²⁺ oxidation depended on the Fe²⁺ concentration, oxygen pressure, amount of recycled sludge, limestone dosage and the mixing rate. Continuous studies in an OPeN process pilot plant resulted in 100% removal of total acidity from synthetic coal mine water and a 98% removal from synthetic gold mine water. Fe²⁺ was removed completely as precipitated Fe(OH)₃ from both synthetic coal and gold mine water at around pH 7 at 200 and 100 kPa oxygen pressure, respectively.

One-step Tape Casting of Composites via Slurry on Fiber

NASA Technical Reports Server (NTRS)

deGroh, Henry C., III

2001-01-01

A process by which metal matrix composites can be made was presented. The process involves putting a powder slurry on fibers to make a precursor green tape. These green tapes are cut, stacked and hot pressed to form the fully dense composite. A computer program was presented which enables complete quantification and control of the process. Once some easily obtained properties of the slurry and its behavior are determined (such as the shrinkage from the wet to green state, and the density of the green tape) modification of the fiber spacing and blade height give the maker precise control of fiber volume fraction, and fiber architecture in the composite. The process was shown to be accurate and flexible through the production of a wide variety of volume fraction fiber composites made from a wide variety of fibers and powders. The most time consuming step of the tape casting process (other than hot pressing) was winding the fiber on the drum. The tape casting techniques developed resulted in high quality metal matrix composites, with ultimate tensile strength in the range of 215 ksi (1477 MPa), a strain at failure of 1.15 percent, and in fatigue at room temperature 0 to 120 ksi, n = 0.3 Hz, a 4-ply Ti-24Al-11Nb/SCS-6, 32 vol% fiber tape cast composite lasted 202,205 cycles with a maximum strain on the 100th cycle of 0.43 percent.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Looney, J.H.; Im, C.J.

Under the sponsorship of DOE/METC, UCC Research completed a program in 1984 concerned with the development, testing, and manufacture of an ultra-clean coal-water mixture fuel using the UCC two-stage physical beneficiation and coal-water mixture preparation process. Several gallons of ultra-clean coal-water slurry produced at the UCC Research pilot facility was supplied to DOE/METC for combustion testing. The finalization of this project resulted in the presentation of a conceptual design and economic analysis of an ultra-clean coal-water mixture processing facility sufficient in size to continuously supply fuel to a 100 MW turbine power generation system. Upon completion of the above program,more » it became evident that substantial technological and economic improvement could be realized through further laboratory and engineering investigation of the UCC two-stage physical beneficiation process. Therefore, as an extension to the previous work, the purpose of the present program was to define the relationship between the controlling technical parameters as related to coal-water slurry quality and product price, and to determine the areas of improvement in the existing flow-scheme, associated cost savings, and the overall effect of these savings on final coal-water slurry price. Contents of this report include: (1) introduction; (2) process refinement (improvement of coal beneficiation process, different source coals and related cleanability, dispersants and other additives); (3) coal beneficiation and cost parametrics summary; (4) revised conceptual design and economic analysis; (5) operating and capital cost reduction; (6) conclusion; and (7) appendices. 24 figs., 12 tabs.« less

Synthesis of Calcite Nano Particles from Natural Limestone assisted with Ultrasonic Technique

NASA Astrophysics Data System (ADS)

Handayani, M.; Sulistiyono, E.; Firdiyono, F.; Fajariani, E. N.

2018-03-01

This article represents a precipitation method assisted with ultrasonic process to synthesize precipitated calcium carbonate nano particles from natural limestone. The synthesis of nanoparticles material of precipitated calcium carbonate from commercial calcium carbonate was done for comparison. The process was performed using ultrasonic waves at optimum condition, that is, at temperature of 80oC for 10 minutes with various amplitudes. Synthesized precipitated calcium carbonate nanoparticles were characterized using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Particle Size Analyzer (PSA). The result of PSA measurements showed that precipitated calcium carbonate nano particles was obtained with the average size of 109 nm.

Evaluation of a lime-mediated sewage sludge stabilisation process. Product characterisation and technological validation for its use in the cement industry.

PubMed

Rodríguez, N Husillos; Granados, R J; Blanco-Varela, M T; Cortina, J L; Martínez-Ramírez, S; Marsal, M; Guillem, M; Puig, J; Fos, C; Larrotcha, E; Flores, J

2012-03-01

This paper describes an industrial process for stabilising sewage sludge (SS) with lime and evaluates the viability of the stabilised product, denominated Neutral, as a raw material for the cement industry. Lime not only stabilised the sludge, raised the temperature of the mix to 80-100°C, furthering water evaporation, portlandite formation and the partial oxidation of the organic matter present in the sludge. Process mass and energy balances were determined. Neutral, a white powder consisting of portlandite (49.8%), calcite (16.6%), inorganic oxides (13.4%) and organic matter and moisture (20.2%), proved to be technologically apt for inclusion as a component in cement raw mixes. In this study, it was used instead of limestone in raw mixes clinkerised at 1400, 1450 and 1500°C. These raw meals exhibited greater reactivity at high temperatures than the limestone product and their calcination at 1500°C yielded clinker containing over 75% calcium silicates, the key phases in Portland clinker. Finally, the two types of raw meal (Neutral and limestone) were observed to exhibit similar mineralogy and crystal size and distribution. Published by Elsevier Ltd.

Continuous inline blending of antimisting kerosene

NASA Technical Reports Server (NTRS)

Parikh, P.; Yavrouian, A.; Sarohia, V.

1985-01-01

A continuous inline blender was developed to blend polymer slurries with a stream of jet A fuel. The viscosity of the slurries ranged widely. The key element of the blender was a static mixer placed immediately downstream of the slurry injection point. A positive displacement gear pump for jet A was employed, and a progressive cavity rotary screw pump was used for slurry pumping. Turbine flow meters were employed for jet A metering while the slurry flow rate was calibrated against the pressure drop in the injection tube. While using one of the FM-9 variant slurries, a provision was made for a time delay between the addition of slurry and the addition of amine sequentially into the jet A stream.

PEP Integrated Test D Run Report Caustic and Oxidative Leaching in UFP-VSL-T02A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sevigny, Gary J.; Bredt, Ofelia P.; Burns, Carolyn A.

2009-12-11

Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed and operated as part of a plan to respond to issue M12, "Undemonstrated Leaching Processes" of the External Flowsheet Review Team (EFRT) issue response plan. The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. Themore » PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing. Two operating scenarios are currently being evaluated for the ultrafiltration process (UFP) and leaching operations. The first scenario (Test B and D) has caustic leaching performed in the UFP-2 ultrafiltration feed vessels (i.e., vessel UFP-VSL-T02A in the PEP and vessels UFP-VSL-00002A and B in the WTP PTF). The second scenario (Test A) has caustic leaching conducted in the UFP-1 ultrafiltration feed preparation vessels (i.e., vessels UFP-VSL-T01A and B in the PEP and vessels UFP VSL-00001A and B in the WTP PTF). In Test D, 19M sodium hydroxide (NaOH, caustic) was added to the waste slurry in the UFP VSL T02 vessel after the solids were concentrated to ~20% undissolved solids. The NaOH was added to leach solid aluminum compounds (e.g., gibbsite, boehmite). Caustic addition is followed by heating to 85°C using direct injection of steam to accelerate the leach process. The main difference of Test D compared to Test B is that the leach temperature is 85°C for 24 hrs as compared to 100°C for 12 hours. The other difference is the Test D simulant had Cr in the simulant from the start of processing and Test B had Cr added to adjust the simulant composition after aluminum leaching. Following the caustic leach, the UFP-VSL-T02A vessel contents are cooled using the vessel cooling jacket. The slurry was then concentrated to 17 wt% undissolved solids and washed with inhibited water to remove NaOH and other soluble salts. Next, the slurry was oxidatively leached using sodium permanganate to solubilize chrome. The slurry was then washed to remove the dissolved chrome and concentrated.« less

Feasibility Process for Remediation of the Crude Oil Contaminated Soil

NASA Astrophysics Data System (ADS)

Keum, H.; Choi, H.; Heo, H.; Lee, S.; Kang, G.

2015-12-01

More than 600 oil wells were destroyed in Kuwait by Iraqi in 1991. During the war, over 300 oil lakes with depth of up to 2m at more than 500 different locations which has been over 49km2. Therefore, approximately 22 million m3was crude oil contaminated. As exposure of more than 20 years under atmospheric conditions of Kuwait, the crude oil has volatile hydrocarbons and covered heavy oily sludge under the crude oil lake. One of crude oil contaminated soil which located Burgan Oilfield area was collected by Kuwait Oil Company and got by H-plus Company. This contaminated soil has about 42% crude oil and could not biodegraded itself due to the extremely high toxicity. This contaminated soil was separated by 2mm sieve for removal oil sludge ball. Total petroleum hydrocarbons (TPH) was analysis by GC FID and initial TPH concentration was average 48,783 mg/kg. Ten grams of the contaminated soil replaced in two micro reactors with 20mL of bio surfactant produce microorganism. Reactor 1 was added 0.1g powder hemoglobin and other reactor was not added hemoglobin at time 0 day. Those reactors shake 120 rpm on the shaker for 7 days and CO2 produced about 150mg/L per day. After 7 days under the slurry systems, the rest days operated by hemoglobin as primary carbon source for enhanced biodegradation. The crude oil contaminated soil was degraded from 48,783mg/kg to 20,234mg/kg by slurry process and final TPH concentration degraded 11,324mg/kg for 21days. Therefore, highly contaminated soil by crude oil will be combined bio slurry process and biodegradation process with hemoglobin as bio catalytic source. Keywords: crude-oil contaminated soil, bio slurry, biodegradation, hemoglobin ACKOWLEDGEMENTS This project was supported by the Korea Ministry of Environment (MOE) GAIA Program

Impact of water flow conditions on the fate of ammonium and nitrate at the interface of the unsaturated and saturated zone

NASA Astrophysics Data System (ADS)

Glöckler, David; Gassen, Niklas; Stumpp, Christine

2017-04-01

Elevated nitrate concentrations in groundwater have caused severe environmental issues in the last decades. Mitigation strategies need to be developed to reduce the amount of nitrate without reducing crop yield though. Therefore, we need to understand nitrogen turnover processes and how they are influenced by hydrogeochemical conditions in the unsaturated and saturated zone. The objective of this study was to investigate the influence of flow conditions on transport processes and the fate of ammonium and nitrate released from slurry application. Experiments were conducted under controlled conditions in an aquifer model setup (1.1 x 0.6 x 0.2 m3). A diluted slurry mix was injected continuously. The inorganic nitrogen compounds were traced under different water regimes regarding recharge rates and water table position (steady-state, transient and stagnant flow conditions). Conservative tracers and mathematical modeling were used to identify water flow and transport. Spatiotemporal changes of dissolved oxygen, ammonium, nitrite, nitrate, dissolved organic carbon and matrix potential were identified through high resolution monitoring (0.05 m). The ecosystem immediately responded to the slurry application with enhanced microbial respiration and the first step of nitrification converting ammonium to nitrite. This process was dominating during the first ten days of the experiment. A complete nitrification was established after 20 days resulting in increasing nitrate concentrations. Less nitrate was measured below the water table during steady state flow conditions in contrast to transient conditions with a fluctuating water table which seemed to inhibit denitrification. Still denitrification was not the dominating process despite high concentration of dissolved organic carbon (4-20 mg/L). Even under stagnant flow conditions, nitrate stayed in the system and denitrification was limited. Anoxic conditions were not established due to the low bioavailability of the dissolved organic carbon. The results highlight the substantial impact of slurry application on groundwater quality for all tested hydrological scenarios.

Effect of fermentation temperature on hydrogen production from cow waste slurry by using anaerobic microflora within the slurry.

PubMed

Yokoyama, Hiroshi; Waki, Miyoko; Moriya, Naoko; Yasuda, Tomoko; Tanaka, Yasuo; Haga, Kiyonori

2007-02-01

We examined hydrogen production from a dairy cow waste slurry (13.4 g of volatile solids per liter) by batch cultures in a temperature range from 37 to 85 degrees C, using microflora naturally present within the slurry. Without the addition of seed bacteria, hydrogen was produced by simply incubating the slurry, using the microflora within the slurry. Interestingly, two peaks of fermentation temperatures for hydrogen production from the slurry were observed at 60 and 75 degrees C (392 and 248 ml H2 per liter of slurry, respectively). After the termination of the hydrogen evolution, the microflora cultured at 60 degrees C displayed hydrogen-consuming activity, but hydrogen-consuming activity of the microflora cultured at 75 degrees C was not detected, at least for 24 days. At both 60 and 75 degrees C, the main by-product was acetate, and the optimum pH of the slurry for hydrogen production was around neutral. Bacteria related to hydrogen-producing moderate and extreme thermophiles, Clostridium thermocellum and Caldanaerobacter subterraneus, were detected in the slurries cultured at 60 and 75 degrees C, respectively, by denaturing gradient gel electrophoresis analyses, using the V3 region of 16S rDNA.

Superheated fuel injection for combustion of liquid-solid slurries

DOEpatents

Robben, F.A.

1984-10-19

A method and device are claimed for obtaining, upon injection, flash evaporation of a liquid in a slurry fuel to aid in ignition and combustion. The device is particularly beneficial for use of coal-water slurry fuels in internal combustion engines such as diesel engines and gas turbines, and in external combustion devices such as boilers and furnaces. The slurry fuel is heated under pressure to near critical temperature in an injector accumulator, where the pressure is sufficiently high to prevent boiling. After injection into a combustion chamber, the water temperature will be well above boiling point at a reduced pressure in the combustion chamber, and flash boiling will preferentially take place at solid-liquid surfaces, resulting in the shattering of water droplets and the subsequent separation of the water from coal particles. This prevents the agglomeration of the coal particles during the subsequent ignition and combustion process, and reduces the energy required to evaporate the water and to heat the coal particles to ignition temperature. The overall effect will be to accelerate the ignition and combustion rates, and to reduce the size of the ash particles formed from the coal. 2 figs., 2 tabs.

Scoping Studies to Evaluate the Benefits of an Advanced Dry Feed System on the Use of Low-Rank Coal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rader, Jeff; Aguilar, Kelly; Aldred, Derek

2012-03-30

The purpose of this project was to evaluate the ability of advanced low rank coal gasification technology to cause a significant reduction in the COE for IGCC power plants with 90% carbon capture and sequestration compared with the COE for similarly configured IGCC plants using conventional low rank coal gasification technology. GE’s advanced low rank coal gasification technology uses the Posimetric Feed System, a new dry coal feed system based on GE’s proprietary Posimetric Feeder. In order to demonstrate the performance and economic benefits of the Posimetric Feeder in lowering the cost of low rank coal-fired IGCC power with carbonmore » capture, two case studies were completed. In the Base Case, the gasifier was fed a dilute slurry of Montana Rosebud PRB coal using GE’s conventional slurry feed system. In the Advanced Technology Case, the slurry feed system was replaced with the Posimetric Feed system. The process configurations of both cases were kept the same, to the extent possible, in order to highlight the benefit of substituting the Posimetric Feed System for the slurry feed system.« less

Optimizing contaminant desorption and bioavailability in dense slurry systems. 2. PAH bioavailability and rates of degradation.

PubMed

Kim, Han S; Weber, Walter J

2005-04-01

The effects of mechanical mixing on rates of polycyclic aromatic hydrocarbon (PAH) biodegradation in dense geosorbent slurry (67% solids content, w/w) systems were evaluated using laboratory-scale intermittently mixed batch bioreactors. A PAH-contaminated soil and a phenanthrene-sorbed mineral sorbent (alpha-Al2O3) were respectively employed as slurry solids in aerobic and anaerobic biodegradation studies. Both slurries exhibited a characteristic behavior of pseudoplastic non-Newtonian fluids, and the impeller revolution rate and its diameter had dramatic impacts on power and torque requirements in their laminar flow mixing. Rates of phenanthrene biodegradation were markedly enhanced by relatively low-level auger mixing under both aerobic and anaerobic (denitrifying) conditions. Parameters for empirical models correlating biodegradation rate coefficient (k(b)) values to the degree of mixing were similar to those for correlations between mass transfer (desorption) rate coefficient (k(r)) values for rapidly desorbing fractions of soil organic matter and degree of mixing reported in a companion study, supporting a conclusion that performance-efficient and cost-effective enhancements of PAH mass transfer (desorption) and its biodegradation processes can be achieved by the introduction of optimal levels of reactor-scale mechanical mixing.

Effect of slurry composition on the chemical mechanical polishing of thin diamond films

PubMed Central

Werrell, Jessica M.; Mandal, Soumen; Thomas, Evan L. H.; Brousseau, Emmanuel B.; Lewis, Ryan; Borri, Paola; Davies, Philip R.; Williams, Oliver A.

2017-01-01

Nanocrystalline diamond (NCD) thin films grown by chemical vapour deposition have an intrinsic surface roughness, which hinders the development and performance of the films’ various applications. Traditional methods of diamond polishing are not effective on NCD thin films. Films either shatter due to the combination of wafer bow and high mechanical pressures or produce uneven surfaces, which has led to the adaptation of the chemical mechanical polishing (CMP) technique for NCD films. This process is poorly understood and in need of optimisation. To compare the effect of slurry composition and pH upon polishing rates, a series of NCD thin films have been polished for three hours using a Logitech Ltd. Tribo CMP System in conjunction with a polyester/polyurethane polishing cloth and six different slurries. The reduction in surface roughness was measured hourly using an atomic force microscope. The final surface chemistry was examined using X-ray photoelectron spectroscopy and a scanning electron microscope. It was found that of all the various properties of the slurries, including pH and composition, the particle size was the determining factor for the polishing rate. The smaller particles polishing at a greater rate than the larger ones. PMID:29057022

Determination of heat conductivity of waste glass feed and its applicability for modeling the batch-to-glass conversion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hujova, Miroslava; Pokorny, Richard; Klouzek, Jaroslav

The heat conductivity of reacting melter feed affects the heat transfer and conversion process in the cold cap (the reacting feed floating on molten glass). To investigate it, we simulated the feed conditions and morphology in the cold-cap by preparing “fast-dried slurry blocks”, formed by rapidly evaporating water from feed slurry poured onto a 200°C surface. A heat conductivity meter was used to measure heat conductivity of samples cut from the fast-dried slurry blocks, samples of a cold cap retrieved from a laboratory-scale melter, and loose dry powder feed samples. Our study indicates that the heat conductivity of the feedmore » in the cold cap is significantly higher than that of loose dry powder feed, resulting from the feed solidification during the water evaporation from the feed slurry. To assess the heat transfer at higher temperatures when feed turns into foam, we developed a theoretical model that predicts the foam heat conductivity based on morphology data from in-situ X-ray computed tomography. The implications for the mathematical modeling of the cold cap are discussed.« less

Effect of slurry composition on the chemical mechanical polishing of thin diamond films

NASA Astrophysics Data System (ADS)

Werrell, Jessica M.; Mandal, Soumen; Thomas, Evan L. H.; Brousseau, Emmanuel B.; Lewis, Ryan; Borri, Paola; Davies, Philip R.; Williams, Oliver A.

2017-12-01

Nanocrystalline diamond (NCD) thin films grown by chemical vapour deposition have an intrinsic surface roughness, which hinders the development and performance of the films' various applications. Traditional methods of diamond polishing are not effective on NCD thin films. Films either shatter due to the combination of wafer bow and high mechanical pressures or produce uneven surfaces, which has led to the adaptation of the chemical mechanical polishing (CMP) technique for NCD films. This process is poorly understood and in need of optimisation. To compare the effect of slurry composition and pH upon polishing rates, a series of NCD thin films have been polished for three hours using a Logitech Ltd. Tribo CMP System in conjunction with a polyester/polyurethane polishing cloth and six different slurries. The reduction in surface roughness was measured hourly using an atomic force microscope. The final surface chemistry was examined using X-ray photoelectron spectroscopy and a scanning electron microscope. It was found that of all the various properties of the slurries, including pH and composition, the particle size was the determining factor for the polishing rate. The smaller particles polishing at a greater rate than the larger ones.

Effects of cattle slurry acidification on ammonia and methane evolution during storage.

PubMed

Petersen, Søren O; Andersen, Astrid J; Eriksen, Jørgen

2012-01-01

Slurry acidification before storage is known to reduce NH(3) emissions, but recent observations have indicated that CH(4) emissions are also reduced. We investigated the evolution of CH(4) from fresh and aged cattle slurry during 3 mo of storage as influenced by pH adjustment to 5.5 with sulfuric acid. In a third storage experiment, cattle slurry acidified with commercial equipment on two farms was incubated. In the manipulation experiments, effects of acid and sulfate were distinguished by adding hydrochloric acid and potassium sulfate separately or in combination, rather than sulfuric acid. In one experiment sulfur was also added to slurry as the amino acid methionine in separate treatments. In each treatment 20-kg portions of slurry (n = 4) were stored for 95 d. All samples were subsampled nine to 10 times for determination of NH(3) and CH(4) evolution rates using a 2-L flow-through system. In all experiments, the pH of acidified cattle slurry increased gradually to between 6.5 and 7. Acidification of slurry reduced the evolution of CH(4) by 67 to 87%. The greatest reduction was observed with aged cattle slurry, which had a much higher potential for CH(4) production than fresh slurry. Sulfate and methionine amendment to cattle slurry without pH adjustment also significantly inhibited methanogenesis, probably as a result of sulfide production. The study suggests that complex microbial interactions involving sulfur transformations and pH determine the potential for CH(4) emission during storage of cattle slurry, and that slurry acidification may be a cost-effective greenhouse gas mitigation option. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Chemical-mechanical polishing of metal and dielectric films for microelectronic applications

NASA Astrophysics Data System (ADS)

Hegde, Sharath

The demand for smaller, faster devices has led the integrated circuit (IC) industry to continually increase the device density on a chip while simultaneously reducing feature dimensions. Copper interconnects and multilevel metallization (MLM) schemes were introduced to meet some of these challenges. With the employment of MLM in the ultra-large-scale-integrated (ULSI) circuit fabrication technology, repeated planarization of different surface layers with tolerance of a few nanometers is required. Presently, chemical-mechanical planarization (CMP) is the only technique that can meet this requirement. Damascene and shallow trench isolation processes are currently used in conjunction with CMP in the fabrication of multilevel copper interconnects and isolation of devices, respectively, for advanced logic and memory devices. These processes, at some stage, require simultaneous polishing of two different materials using a single slurry that offers high polish rates, high polish selectivity to one material over the other and good post-polish surface finish. Slurries containing one kind of abrasive particles do not meet most of these demands due mainly to the unique physical and chemical properties of each abrasive. However, if a composite particle is formed that takes the advantages of different abrasives while mitigating their disadvantages, the CMP performance of resulting abrasives would be compelling. It is demonstrated that electrostatic interactions between ceria and silica particles at pH 4 can be used to produce composite particles with enhanced functionality. Zeta potential measurement and TEM images used for particle characterization show the presence of such composite particles with smaller shell particles attached onto larger core particles. Slurries containing ceria (core)/silica (shell) and silica (core)/ceria (shell) composite particles when used to polish metal and dielectric films, respectively, yield both enhanced metal and dielectric film removal rates and better post-polish surface roughness values compared to those containing single kind of particles. Several arguments are proposed to explain the enhanced CMP performance with the composite abrasives. The effect of surface charge of the composite abrasive and the hardness of the core particles in the composite abrasives contained in the polishing slurry on polish rates of different films is discussed. Also, as a part of this thesis, several issues related to CMP were addressed. The planarization ability of Cu CMP slurry containing alumina coated silica particles was studied to elucidate the role of pattern geometry in affecting polish rate and also generating pattern dependent defects like dishing and erosion. Additionally, a polishing process was devised which, when viewed with the optical profilometer, eliminated surface defects including shallow and deep scratches and pits already present in a copper film. Also, molybdenum dioxide (MoO2) was evaluated as a potential abrasive for a highly reactive copper CMP slurry with potassium iodate as the oxidizing agent. Finally, the interaction of amino acid additives in ceria slurries with the silicon nitride film during STI CMP is discussed. Directions for future work have been presented at the end of the thesis.

Automated Coal-Mining System

NASA Technical Reports Server (NTRS)

Gangal, M. D.; Isenberg, L.; Lewis, E. V.

1985-01-01

Proposed system offers safety and large return on investment. System, operating by year 2000, employs machines and processes based on proven principles. According to concept, line of parallel machines, connected in groups of four to service modules, attacks face of coal seam. High-pressure water jets and central auger on each machine break face. Jaws scoop up coal chunks, and auger grinds them and forces fragments into slurry-transport system. Slurry pumped through pipeline to point of use. Concept for highly automated coal-mining system increases productivity, makes mining safer, and protects health of mine workers.

Physics of loose abrasive microgrinding.

PubMed

Golini, D; Jacobs, S D

1991-07-01

This study examined the physics of loose abrasive microgrinding (grinding with micron and submicron sized abrasives). More specifically, it focused on the transition from brittle to ductile mode grinding which occurs in this region of abrasive sizes. Process dependency on slurry chemistry was the primary area of emphasis and was studied for diamond abrasives varying in size from 3.0 to 0.75 microm on both ULE and Zerodur, with emphasis on ULE. Ductile mode grinding was achieved with smaller abrasives, as expected, however two significant discoveries were made. The first observation was that by simply changing slurry chemistry, it was possible to induce the transition from brittle fracture to ductile mode grinding in ULE. This transition point could be intentionally moved about for diamonds 3.0-0.75 microm in diameter. For any given abrasive size within these limits, either brittle fracture or ductile removal may be achieved, depending on the slurry used to suspend the diamonds. Several slurries were studied, including water, a series of homologous n-alcohols, and other solvents chosen for properties varying from molecular size to dielectric constant and zeta potential. The study revealed that this slurry dependency is primarily a Rebinder effect. The second finding was that a tremendous amount of surface stress is introduced in loose abrasive ductile mode grinding. This stress was observed when the Twyman Effect in ULE plates increased by a factor of 4 in the transition from the brittle to the ductile mode. An assessment of the cause of this stress is discussed.

Structure and properties of stir-cast zinc alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

LeHuy, H.; Blain J.; Masounave, J.

Stir casting (or rheocasting) of ZA-27 zinc alloys was investigated experimentally. By vigorously agitating the alloys during cooling, the dendrites that were forming were fragmented giving a unique structure composed of spherical and rosette shaped particles suspended in the remaining liquid. Under high shear rates ({center dot}{gamma} = 300s{sup {minus}1} or more) the slurries with primary particle concentrations as high as 60% displayed viscosities as low as 20 poises and could easily be casted. The effects of processing variables such as shearing and cooling rates and casting temperatures were studied. Their relative importance on the rheological and microstructural behavior ofmore » the stir cast alloys are discussed. Results from viscosity measurements on slurries show that non-dendritical ZA-27 alloys obey a power law fluid model. Finally, results from mechanical and compressive studies carried out on solidified slurries are discussed and compared to conventional casted and wrought alloy properties.« less

Separation of catalyst from Fischer-Tropsch slurry

DOEpatents

White, Curt M.; Quiring, Michael S.; Jensen, Karen L.; Hickey, Richard F.; Gillham, Larry D.

1998-10-27

In a catalytic process for converting synthesis gas including hydrogen and carbon monoxide to hydrocarbons and oxygenates by a slurry Fischer-Tropsch synthesis, the wax product along with dispersed catalyst is removed from the slurry and purified by removing substantially all of the catalyst prior to upgrading the wax and returning a portion to the Fischer-Tropsch reaction. Separation of the catalyst particles from the wax product is accomplished by dense gas and/or liquid extraction in which the organic compounds in the wax are dissolved and carried away from the insoluble inorganic catalyst particles that are primarily inorganic in nature. The purified catalyst free wax product can be subsequently upgraded by various methods such as hydrogenation, isomerization, hydrocracking, conversion to gasoline and other products over ZSM-5 aluminosilicate zeolite, etc. The catalyst particles are returned to the Fischer-Tropsch Reactor by slurring them with a wax fraction of appropriate molecular weight, boiling point and viscosity to avoid reactor gelation.

Protein Concentrate Production from Thin Stillage.

PubMed

Ratanapariyanuch, Kornsulee; Shim, Youn Young; Emami, Shahram; Reaney, Martin J T

2016-12-21

Two-stage fermentation (TSF) of saccharified wheat with a consortium of endemic lactobacilli produced CO 2 and induced colloid separation of fermented solution to produce a protein concentrate (PC). Protein-rich slurry (50%, db) was obtained by decanting solution or skimming floating material during or after TSF. Washing and drying processes were explored to improve protein content, extend storage life of slurry, and yield converted stillage for compound recovery. Centrifuging and washing slurry afforded a PC and clarified solution. PC protein content increased to 60% (w/w, db). The PC was dried in a spray dryer or drum dryer or tray dryer. Dried PC water activity ranged 0.23-0.30. The dried PC lysine content was low, but lysine availability (95%) was excellent. Liquid from TSF and washing was readily microfiltered. Mass recovery of protein, glycerol, 1,3-propanediol, lactic acid, acetic acid, and glycerylphosphorylcholine from combined TSF, washing, and filtration were 66, 76, 72, 77, 74, and 84%, respectively.

Zeolite Combined with Alum and Polyaluminum Chloride Mixed with Agricultural Slurries Reduces Carbon Losses in Runoff from Grassed Soil Boxes.

PubMed

Murnane, J G; Brennan, R B; Fenton, O; Healy, M G

2016-11-01

Carbon (C) losses from agricultural soils to surface waters can migrate through water treatment plants and result in the formation of disinfection by-products, which are potentially harmful to human health. This study aimed to quantify total organic carbon (TOC) and total inorganic C losses in runoff after application of dairy slurry, pig slurry, or milk house wash water (MWW) to land and to mitigate these losses through coamendment of the slurries with zeolite (2.36-3.35 mm clinoptilolite) and liquid polyaluminum chloride (PAC) (10% AlO) for dairy and pig slurries or liquid aluminum sulfate (alum) (8% AlO) for MWW. Four treatments under repeated 30-min simulated rainfall events (9.6 mm h) were examined in a laboratory study using grassed soil runoff boxes (0.225 m wide, 1 m long; 10% slope): control soil, unamended slurries, PAC-amended dairy and pig slurries (13.3 and 11.7 kg t, respectively), alum-amended MWW (3.2 kg t), combined zeolite and PAC-amended dairy (160 and 13.3 kg t zeolite and PAC, respectively) and pig slurries (158 and 11.7 kg t zeolite and PAC, respectively), and combined zeolite and alum-amended MWW (72 and 3.2 kg t zeolite and alum, respectively). The unamended and amended slurries were applied at net rates of 31, 34, and 50 t ha for pig and dairy slurries and MWW, respectively. Significant reductions of TOC in runoff compared with unamended slurries were measured for PAC-amended dairy and pig slurries (52 and 56%, respectively) but not for alum-amended MWW. Dual zeolite and alum-amended MWW significantly reduced TOC in runoff compared with alum amendment only. We conclude that use of PAC-amended dairy and pig slurries and dual zeolite and alum-amended MWW, although effective, may not be economically viable to reduce TOC losses from organic slurries given the relatively low amounts of TOC measured in runoff from unamended slurries compared with the amounts applied. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Diagenetic history of late Oligocene-early Miocene carbonates in East Sabah, Malaysia

NASA Astrophysics Data System (ADS)

Zainal Abidin, N. S.; Raymond, R. R.; Bashah, N. S. I.

2017-10-01

Limestones are particularly susceptible to drastic early diagenesis modifications, mainly cementation and dissolution. During the early Miocene, a major tectonic deformation has caused a widespread of uplift in Sabah. This has resulted change in depositional environment from deep to shallow marine, which favours the deposition of Gomantong Limestone. This study aims to investigate the diagenetic history of Gomantong Limestone in East Sabah. Thorough understanding of the diagenetic processes may provide data to unravel the tectonic activities which affected the reservoir quality of the carbonates. Combining the data from comprehensive petrographic analysis, and Scanning Electron Microscopy (SEM) of 30 samples, two main cements type were identified. These are microcrystalline cement and Mg-calcite cement of granular and blocky mosaics which are dominantly seen in all samples. The sequence of diagenesis events are determined as (1) micritization; (2) grain scale compaction; (3) cementation (pore-filling); (4) mechanical compaction and cementation infilling fractures and (5) chemical compaction. These diagenetic events are interpreted as reflection of changes in diagenetic environment from shallow marine to deep burial. The massive cementation in the Gomantong Limestone has resulted into a poor reservoir quality.

Biogas slurry pricing method based on nutrient content

NASA Astrophysics Data System (ADS)

Zhang, Chang-ai; Guo, Honghai; Yang, Zhengtao; Xin, Shurong

2017-11-01

In order to promote biogas-slurry commercialization, A method was put forward to valuate biogas slurry based on its nutrient contents. Firstly, element contents of biogas slurry was measured; Secondly, each element was valuated based on its market price, and then traffic cost, using cost and market effect were taken into account, the pricing method of biogas slurry were obtained lastly. This method could be useful in practical production. Taking cattle manure raw meterial biogas slurry and con stalk raw material biogas slurry for example, their price were 38.50 yuan RMB per ton and 28.80 yuan RMB per ton. This paper will be useful for recognizing the value of biogas projects, ensuring biogas project running, and instructing the cyclic utilization of biomass resources in China.

Evaluation of hybrid slurry resulting from the introduction of additives to mineral slurry.

DOT National Transportation Integrated Search

2011-09-01

Drilled shaft construction often requires the use of drill slurry to maintain borehole stability during excavation : and concreting. Florida Department of Transportation (FDOT) specifications require the use of mineral slurry : for all primary struct...

Novel Hydroxyapatite Coatings for the Conservation of Marble and Limestone

NASA Astrophysics Data System (ADS)

Naidu, Sonia

Marble and limestone are calcite-based materials used in the construction of various structures, many of which have significant artistic and architectural value. Unfortunately, due to calcite's high dissolution rate, these stones are susceptible to chemically-induced weathering in nature. Limestone, due to its inherent porosity, also faces other environmental weathering processes that cause weakening from disintegration at grain boundaries. The treatments presently available are all deficient in one way or another. The aim of this work is to examine the feasibility of using hydroxyapatite (HAP) as a novel protective coating for marble and limestone, with two goals: i) to reduce acid corrosion of marble and ii) to consolidate physically weathered limestone. The motivation for using HAP is its low dissolution rate and structural compatibility with calcite. Mild, wet chemical synthesis routes, in which inorganic phosphate-based solutions were reacted with marble and limestone, alone and with other precursors, were used to produce HAP films. Film nucleation, growth and phase evolution were studied on marble to understand film formation and determine the optimal synthesis route. An acid resistance test was developed to investigate the attack mechanism on marble and quantify the efficacy of HAP-based coatings. Film nucleation and growth were dependent on substrate surface roughness and increased with calcium and carbonate salt additions during synthesis. Acid attack on marble occurred via simultaneous dissolution at grain boundaries, twin boundaries and grain surfaces. HAP provided intermediate protection against acid attack, when compared to two conventional treatments. Its ability to protect the stone from acid was not as significant as predicted from dissolution kinetics and this was attributed to incomplete coverage and residual porosity within the film, arising from its flake-like crystal growth habit, which enabled acid to access the underlying substrate. The effectiveness of HAP as a consolidant for weathered limestone, alone and coupled with a commercially available consolidant (ConservareRTM OH-100), was also investigated. To artificially weather limestone in the lab, a reproducible thermal degradation technique was utilised. The dynamic elastic modulus, water sorptivity and coating composition of treated stones were evaluated. HAP was found to be an effective consolidant for limestone, as it restored the elastic modulus of damaged stones to their original values and exhibited superior performance to ConservareRTM OH-100.

Abrasive slurry jet cutting model based on fuzzy relations

NASA Astrophysics Data System (ADS)

Qiang, C. H.; Guo, C. W.

2017-12-01

The cutting process of pre-mixed abrasive slurry or suspension jet (ASJ) is a complex process affected by many factors, and there is a highly nonlinear relationship between the cutting parameters and cutting quality. In this paper, guided by fuzzy theory, the fuzzy cutting model of ASJ was developed. In the modeling of surface roughness, the upper surface roughness prediction model and the lower surface roughness prediction model were established respectively. The adaptive fuzzy inference system combines the learning mechanism of neural networks and the linguistic reasoning ability of the fuzzy system, membership functions, and fuzzy rules are obtained by adaptive adjustment. Therefore, the modeling process is fast and effective. In this paper, the ANFIS module of MATLAB fuzzy logic toolbox was used to establish the fuzzy cutting model of ASJ, which is found to be quite instrumental to ASJ cutting applications.

Syntectic Reactions involving Limestones and Limestone-Derived Carbonatitic Melts in the Generation of some Peralkalic Magmas: Reflections on Reginald Daly's Insights 100 Years Later

NASA Astrophysics Data System (ADS)

Lentz, D.

2017-12-01

The theoretical analysis of how sedimentary limestones and marbles could melt as a result of infiltrative contact metasomatism associated with silicate magmas, enables reconsideration of the limestone syntectic (assimilation) hypothesis for the origin of some peralkalic rocks. Reginald Daly's syntectic model published in detail in early 1918 fell out of favor because experimental evidence from the early 1960's suggested; 1) that limestone assimilation would increase P(CO2) and cause solidification of the silicate intrusion, 2) that there is a thermal barrier between silica-saturated and undersaturated magmas that would inhibit extensive desilication of the magma, and 3) the endothermic decarbonation reactions would require heat via magmatic crystallization of near-solidus magmas. However, these concerns were not as critical for high-T mafic melts relative to more low-T silicic melts, although most subsequent researchers dismissed syntexis as isotopic arguments also seemed robust. However, skarn-related limestone melts can interact much more easily with silicate magma, resulting in calc-silicate-forming (endoskarn-like) limestone syntectic (desilication - calcification-magnesification processes) decarbonation reactions with compositional evolution into the silica-undersaturated field. If mafic in composition originally when syntectically modified, then the CO2-bearing derivative peralkalic melt may subsequently react with the dominant volume magma or fractionate separately into a more evolved composition. As well, an increase in P(CO2) within the modified silicate fraction coupled with compositional evolution to more silica-undersaturated compositions enhances the stability of the immiscible, extremely low viscosity carbonate melt fraction. In addition, dynamic interaction of these co-existing immiscible melts (analogous to the current hypothesis) would partition elements, as well as isotopic signatures, such that they would be virtually unrecognizable as having a crustal level syntectic origin, based on mass-balance principles and Rayleigh decarbonation isotopic equilibria, as they do in many infiltrative skarn systems. Essentially, this partly vindicates the basic premise of Daly's limestone syntectic hypothesis for the origin of some peralkalic igneous rocks.

End-member modelling of isothermal remanent magnetization (IRM) acquisition curves: a novel approach to diagnose remagnetization

NASA Astrophysics Data System (ADS)

Gong, Z.; Dekkers, M. J.; Heslop, D.; Mullender, T. A. T.

2009-08-01

To identify remagnetization is essential for palaeomagnetic studies and their geodynamic implications. The traditional approach is often based on directional analysis of palaeomagnetic data and field tests, which may be inconclusive if the apparent polar wander path (APWP) is poorly constrained or if the remagnetization predates folding. In several cases, rock magnetic work, particularly, the measurement of hysteresis loops allows identification of the so-called `remagnetized' and `non-remagnetized' trends. However, for weakly magnetic samples, this approach can be equivocal. Here, to improve the diagnosis of remagnetization, we investigated 192 isothermal remanent magnetization (IRM) acquisition curves (up to 700 mT) of remagnetized and non-remagnetized limestones from the Organyà Basin, northern Spain. Also, 96 IRM acquisition curves from non-remagnetized marls were studied as a cross-check for the non-remagnetized limestones. A non-parametric end-member modelling approach is used to analyse the IRM acquisition curve data sets. First, remagnetized and non-remagnetized groups were treated separately. Two or three end-members were found to adequately describe the data variability: one end-member represents the high-coercivity contribution, whereas the low-coercivity part can be described by either one end-member or two reasonably similar end-members. In the remagnetized limestones, the low-coercivity end-members tend to saturate at higher field values than in the non-remagnetized limestones. When the entire data set was processed together, a three-end-member model was judged optimal. This model consists of a high-coercivity end-member, a low-coercivity end-member that saturates at ~300-400 mT and a low-coercivity end-member that approximately saturates at 700 mT. Higher contributions of the latter end-member appear to occur dominantly in the remagnetized limestones, whereas the reverse is true for the non-remagnetized limestones, so they plot in clearly distinguishable areas. Meanwhile, the IRM curves from non-remagnetized marls show a behaviour similar to that of the non-remagnetized end-member in the limestones. Therefore, this new approach can be a very useful tool to diagnose remagnetization in weakly magnetic limestones and marls. We recommend applying it to other areas of potentially remagnetized low-intensity sediments.

A new magnetic compound fluid slurry and its performance in magnetic field-assisted polishing of oxygen-free copper

NASA Astrophysics Data System (ADS)

Wang, Youliang; Wu, Yongbo; Guo, Huiru; Fujimoto, Masakazu; Nomura, Mitsuyoshi; Shimada, Kunio

2015-05-01

In nano-precision surface finishing of engineering materials using MCF (magnetic compound fluid) slurry, the water-based MCF slurry is preferable from the viewpoint of the environmental issue and the running cost of cleaning workpiece and equipment. However, the uncoated-CIPs (carbonyl-iron-powders) within the conventional MCF slurry have low ability against aqueous corrosion, leading to the performance deterioration and working life shortening of the conventional MCF slurry. This study proposed a new MCF slurry containing ZrO2-coated CIPs instead of the uncoated CIPs. Its performance in the polishing of oxygen-free copper was compared experimentally with that of the conventional one. The results showed that the work-surface finish polished with the new slurry was in the same level as that with the conventional one when the slurry was used soon after prepared, i.e., the settling time was 0 min; however, as the settling time increased the uncoated-CIPs got rusty, leading to a deterioration in the slurry performance. By contrast, no rust was observed on ZrO2-coated CIPs even the settling time reached several days, indicating the employment of ZrO2-coated CIPs prolonged the working-life of the MCF slurry greatly.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sommer, T.; Melick, T.; Morrison, D.

The objective of this DOE sponsored project was to successfully fire coal-water slurry in a fire-tube boiler that was designed for oil/gas firing and establish a data base that will be relevant to a large number of existing installations. Firing slurry in a fire-tube configuration is a very demanding application because of the extremely high heat release rates and the correspondingly low furnace volume where combustion can be completed. Recognizing that combustion efficiency is the major obstacle when firing slurry in a fire-tube boiler, the program was focused on innovative approaches for improving carbon burnout without major modifications to themore » boiler. The boiler system was successfully designed and operated to fire coal-water slurry for extended periods of time with few slurry related operational problems. The host facility was a 3.8 million Btu/hr Cleaver-Brooks fire-tube boiler located on the University of Alabama Campus. A slurry atomizer was designed that provided outstanding atomization and was not susceptible to pluggage. The boiler was operated for over 1000 hours and 12 shipments of slurry were delivered. The new equipment engineered for the coal-water slurry system consisted of the following: combustion air and slurry heaters; cyclone; baghouse; fly ash reinjection system; new control system; air compressor; CWS/gas burner and gas valve train; and storage tank and slurry handling system.« less

Effects of storage in ozonised slurry ice on the sensory and microbial quality of sardine (Sardina pilchardus).

PubMed

Campos, Carmen A; Rodríguez, Oscar; Losada, Vanesa; Aubourg, Santiago P; Barros-Velázquez, Jorge

2005-08-25

The use of slurry ice, both alone and in combination with ozone, as compared with traditional flake ice was investigated as a new refrigeration system for the storage of sardine (Sardina pilchardus). Microbiological, chemical and sensory analyses were carried out throughout a storage period of 22 days. According to sensory analyses, sardine specimens stored in ozonised slurry ice had a shelf life of 19 days, while counterpart batches stored in slurry ice or flake ice had shelf lives of 15 and 8 days, respectively. Storage in ozonised slurry ice led to significantly lower counts of aerobic mesophiles, psychrotrophic bacteria, anaerobes, coliforms, and both lipolytic and proteolytic microorganisms in sardine muscle, and of surface counts of mesophiles and psychrotrophic bacteria in sardine skin as compared with the slurry ice and the flake ice batches. In all cases, the slurry ice batch also exhibited significantly lower microbial counts, both in muscle and skin, than the flake ice batch. Chemical parameters revealed that the use of slurry ice slowed down the formation of TVB-N and TMA-N to a significant extent in comparison with storage in flake ice. A combination of slurry ice with ozone also allowed a better control of pH and TMA-N formation as compared with slurry ice alone. This work demonstrates that the combined use of slurry ice and ozone for the storage of sardine can be recommended to improve the quality and extend the shelf life of this fish species.

Phosphoric acid based pretreatment of switchgrass and fermentation of entire slurry to ethanol using a simplified process.

PubMed

Wu, Wei; Rondon, Vanessa; Weeks, Kalvin; Pullammanappallil, Pratap; Ingram, Lonnie O; Shanmugam, K T

2018-03-01

Switchgrass (Alamo) was pretreated with phosphoric acid (0.75 and 1%, w/w) at three temperatures (160, 175 and 190 °C) and time (5, 7.5 and 10 min) using a steam gun. The slurry after pretreatment was liquefied by enzymes and the released sugars were fermented in a simultaneous saccharification and co-fermentation process to ethanol using ethanologenic Escherichia coli strain SL100. Among the three variables in pretreatment, temperature and time were critical in supporting ethanol titer and yield. Enzyme hydrolysis significantly increased the concentration of furans in slurries, apparently due to release of furans bound to the solids. The highest ethanol titer of 21.2 ± 0.3 g/L ethanol obtained at the pretreatment condition of 190-1-7.5 (temperature-acid concentration-time) and 10% solids loading accounted for 190 ± 2.9 g ethanol/kg of raw switch grass. This converts to 61.7 gallons of ethanol per ton of dry switchgrass, a value that is comparable to other published pretreatment conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Apparatus and process for depositing hard coating in a nozzle orifice

DOEpatents

Flynn, P.L.; Giammarise, A.W.

1994-12-20

The present invention is directed to a process for coating the interior surfaces of an orifice in a substrate that forms a slurry fuel injection nozzle. In a specific embodiment, the nozzle is part of a fuel injection system for metering a coal-water slurry into a large, medium-speed, multi-cylinder diesel engine. In order to retard erosion of the orifice, the substrate is placed in a chemical vapor deposition (CVD) reaction chamber. A reaction gas is passed into the chamber at a gas temperature below its reaction temperature and is directed through the orifice in the substrate. The gas reaction temperature is a temperature at and above which the reaction gas deposits as a coating, and the reaction gas is of a composition whereby improved resistance to erosion by flow of the particulates in the slurry fuel is imparted by the deposited coating. Only the portion of the substrate in proximity to the orifice to be coated is selectively heated to at least the gas reaction temperature for effecting coating of the orifice's interior surfaces by the vapor deposited coating formed from the reaction gas. 2 figures.

Software Computes Tape-Casting Parameters

NASA Technical Reports Server (NTRS)

deGroh, Henry C., III

2003-01-01

Tcast2 is a FORTRAN computer program that accelerates the setup of a process in which a slurry containing metal particles and a polymeric binder is cast, to a thickness regulated by a doctor blade, onto fibers wound on a rotating drum to make a green precursor of a metal-matrix/fiber composite tape. Before Tcast2, setup parameters were determined by trial and error in time-consuming multiple iterations of the process. In Tcast2, the fiber architecture in the final composite is expressed in terms of the lateral distance between fibers and the thickness-wise distance between fibers in adjacent plies. The lateral distance is controlled via the manner of winding. The interply spacing is controlled via the characteristics of the slurry and the doctor-blade height. When a new combination of fibers and slurry is first cast and dried to a green tape, the shrinkage from the wet to the green condition and a few other key parameters of the green tape are measured. These parameters are provided as input to Tcast2, which uses them to compute the doctor-blade height and fiber spacings needed to obtain the desired fiber architecture and fiber volume fraction in the final composite.

Removal of endosulfan and methoxychlor from water on carbon slurry.

PubMed

Gupta, Vinod K; Ali, Imran

2008-02-01

A carbon slurry, produced in generators of fuel-oil-based industrial generators was converted into an effective and efficient adsorbent for the removal of endosulfan and methoxychlor from aqueous solution. The adsorbent was chemically treated, activated, characterized, and used for the adsorption of endosulfan and methoxychlor pesticides. The maximum adsorption was found at 90 min, 6.5 pH, 0.025 g/L dose, and 25 degrees C temperature. Langmuir and Freundlich adsorption models were applied to analyze adsorption data, and the former was found applicable to this adsorption system in terms of relatively high regression values. The thermodynamic aspect of the process was also investigated by evaluating certain important parameters (enthalpy, free energy, and entropy of system). Kinetics of adsorption was found to follow the pseudo second order rate equation. The diffusion of pesticides into carbon slurry pores was suggested to be the rate controlling step by applying Bangham's equation. Adsorption on a column was also investigated in a continuous flow system. Adsorption efficiencies of endosulfan and methoxychlor were 34.11 and 36.06 mg/g in batch processes and 32.62 and 33.52 mg/g in column operations, respectively.

EFRT M12 Issue Resolution: Comparison of PEP and Bench-Scale Oxidative Leaching Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rapko, Brian M.; Brown, Christopher F.; Eslinger, Paul W.

2009-08-14

Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed and constructed and is to be operated as part of a plan to respond to issue M12, “Undemonstrated Leaching Processes.” The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processesmore » using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing. Two operating scenarios are currently being evaluated for the ultrafiltration process (UFP) and leaching operations. The first scenario has caustic leaching performed in the UFP-2 ultrafiltration feed vessels (i.e., vessel UFP-VSL-T02A in the PEP; and vessels UFP-VSL-00002A and B in the WTP PTF). The second scenario has caustic leaching conducted in the UFP-1 ultrafiltration feed preparation vessels (i.e., vessels UFP-VSL-T01A and B in the PEP; vessels UFP-VSL-00001A and B in the WTP PTF). In both scenarios, 19-M sodium hydroxide solution (NaOH, caustic) is added to the waste slurry in the vessels to dissolve solid aluminum compounds (e.g., gibbsite, boehmite). Caustic addition is followed by a heating step that uses direct steam injection to accelerate the leaching process. Following the caustic leach, the vessel contents are cooled using vessel cooling jackets and/or external heat exchangers. The main difference between the two scenarios is that for leaching in UFP1, the 19-M NaOH is added to un-concentrated waste slurry (3 to 8 wt% solids), while for leaching in UFP2, the slurry is concentrated to nominally 20 wt% solids using cross-flow ultrafiltration before the addition of caustic. For wastes that have significantly high chromium content, the caustic leaching and slurry dewatering is followed by adding sodium permanganate to UFP-VSL-T02A, and the slurry is subjected to oxidative leaching at nominally ambient temperature. The purpose of the oxidative leaching is to selectively oxidize the poorly alkaline-soluble Cr(III) believed to be the insoluble form in Hanford tank sludge to the much more alkaline-soluble Cr(VI), e.g., chromate. The work described in this report provides the test results that are related to the efficiency of the oxidative leaching process to support process modeling based on tests performed with a Hanford waste simulant. The tests were completed both at the lab-bench scale and in the PEP. The purpose of this report is to summarize the results from both scales that are related to oxidative leaching chemistry to support a scale factor for the submodels to be used in the G2 model, which predicts WTP operating performance. Owing to schedule constraints, the PEP test data to be included in this report are limited to those from Integrated Tests A (T01 A/B caustic leaching) and B (T02A caustic leaching).« less

Method of making a functionally graded material

DOEpatents

Lauf, Robert J.; Menchhofer, Paul A.; Walls, Claudia A.; Moorhead, Arthur J.

2002-01-01

A gelcasting method of making an internally graded article alternatively includes the steps of: preparing a slurry including a least two different phases suspended in a gelcasting solution, the phases characterized by having different settling characteristics; casting the slurry into a mold having a selected shape; allowing the slurry to stand for a sufficient period of time to permit desired gravitational fractionation in order to achieve a vertical compositional gradient in the molded slurry; gelling the slurry to form a solid gel while preserving the vertical compositional gradient in the molded slurry; drying the gel to form a dried green body; and sintering the dry green body to form a solid object, at least one property thereof varying along the vertical direction because of the compositional gradient in the molded slurry.

Ultrasound Analysis of Slurries

DOEpatents

Soong, Yee and Blackwell, Arthur G.

2005-11-01

An autoclave reactor allows for the ultrasonic analysis of slurry concentration and particle size distribution at elevated temperatures and pressures while maintaining the temperature- and pressure-sensitive ultrasonic transducers under ambient conditions. The reactor vessel is a hollow stainless steel cylinder containing the slurry which includes a stirrer and a N, gas source for directing gas bubbles through the slurry. Input and output transducers are connected to opposed lateral portions of the hollow cylinder for respectively directing sound waves through the slurry and receiving these sound waves after transmission through the slurry, where changes in sound wave velocity and amplitude can be used to measure slurry parameters. Ultrasonic adapters connect the transducers to the reactor vessel in a sealed manner and isolate the transducers from the hostile conditions within the vessel without ultrasonic signal distortion or losses.

Ultrasound Analysis Of Slurries

DOEpatents

Soong, Yee; Blackwell, Arthur G.

2005-11-01

An autoclave reactor allows for the ultrasonic analysis of slurry concentration and particle size distribution at elevated temperatures and pressures while maintaining the temperature- and pressure-sensitive ultrasonic transducers under ambient conditions. The reactor vessel is a hollow stainless steel cylinder containing the slurry which includes a stirrer and a N.sub.2 gas source for directing gas bubbles through the slurry. Input and output transducers are connected to opposed lateral portions of the hollow cylinder for respectively directing sound waves through the slurry and receiving these sound waves after transmission through the slurry, where changes in sound wave velocity and amplitude can be used to measure slurry parameters. Ultrasonic adapters connect the transducers to the reactor vessel in a sealed manner and isolate the transducers from the hostile conditions within the vessel without ultrasonic signal distortion or losses.

Investigation of aluminum gate CMP in a novel alkaline solution

NASA Astrophysics Data System (ADS)

Cuiyue, Feng; Yuling, Liu; Ming, Sun; Wenqian, Zhang; Jin, Zhang; Shuai, Wang

2016-01-01

Beyond 45 nm, due to the superior CMP performance requirements with the metal gate of aluminum in the advanced CMOS process, a novel alkaline slurry for an aluminum gate CMP with poly-amine alkali slurry is investigated. The aluminum gate CMP under alkaline conditions has two steps: stock polishing and fine polishing. A controllable removal rate, the uniformity of aluminum gate and low corrosion are the key challenges for the alkaline polishing slurry of the aluminum gate CMP. This work utilizes the complexation-soluble function of FA/O II and the preference adsorption mechanism of FA/O I nonionic surfactant to improve the uniformity of the surface chemistry function with the electrochemical corrosion research, such as OCP-TIME curves, Tafel curves and AC impedance. The result is that the stock polishing slurry (with SiO2 abrasive) contains 1 wt.% H2O2,0.5 wt.% FA/O II and 1.0 wt.% FA/O I nonionic surfactant. For a fine polishing process, 1.5 wt.% H2O2, 0.4 wt.% FA/O II and 2.0 wt.% FA/O I nonionic surfactant are added. The polishing experiments show that the removal rates are 3000 ± 50 Å/min and 1600 ± 60 Å/min, respectively. The surface roughnesses are 2.05 ± 0.128 nm and 1.59 ± 0.081 nm, respectively. A combination of the functions of FA/O II and FA/O I nonionic surfactant obtains a controllable removal rate and a better surface roughness in alkaline solution.

Fermentation of Anaerobic Cow Waste as Bio-Slurry Organic Fertilizer and Nitrogen Chemical Fertilizer on Soybean

NASA Astrophysics Data System (ADS)

Yafizham; Sutarno

2018-02-01

The study aimed was to evaluate the effect of bio-slurry organic fertilizer and urea chemical fertilizer combination on fresh material weight, phosphorus and potassium soybean straw, and seed weight per soybean plant plot. The experiment was conducted with a randomized block design with a single treatment repeated 5 times consisting of P0: control (without fertilizer), P1: bio-slurry 10 t/ha + 25 kg of N/ha, P2: bio-slurry 10 t/ha + 50 kg of N/ha, P3: bio-slurry 10 t/ha + 75 kg of N/ha, P4: bio-slurry 10 t/ha + 100 kg of N/ha and P5: bio-slurry 10 t/ha. The results showed that bio-slurry treatment of 10 t/ha + 25 kg of N/ha resulted in the highest fresh weight and dry weight of soybean plants, respectively of 240.7 g and 22.33 g, but not significantly different from the bio-slurry treatment of 10 t/ha + 50 kg of N/ha which yielded fresh weight of 197.7 g and a dry weight of 19.08 g. P production of 10.23 g per plant was significantly higher than other treatments but didn’t differ significantly between P2 and P4 treatments of 8.05 and 7.17 g per plant. The bio-slurry treatment of 10 t/ha + 25 kg of N/ha also yielded K of 6.46 g per plant butn’t unlike the bio-slurry treatment of 10 t/ha + 50 kg of N/ha. While the number of pods per plant and weight of 100 grains of the highest soybean seeds were also produced from bio-slurry treatment of 10 t/ha + 25 kg of N/ha.

Simultaneous heterotrophic and sulfur-oxidizing autotrophic denitrification process for drinking water treatment: control of sulfate production.

PubMed

Sahinkaya, Erkan; Dursun, Nesrin; Kilic, Adem; Demirel, Sevgi; Uyanik, Sinan; Cinar, Ozer

2011-12-15

A long-term performance of a packed-bed bioreactor containing sulfur and limestone was evaluated for the denitrification of drinking water. Autotrophic denitrification rate was limited by the slow dissolution rate of sulfur and limestone. Dissolution of limestone for alkalinity supplementation increased hardness due to release of Ca(2+). Sulfate production is the main disadvantage of the sulfur autotrophic denitrification process. The effluent sulfate concentration was reduced to values below drinking water guidelines by stimulating the simultaneous heterotrophic and autotrophic denitrification with methanol supplementation. Complete removal of 75 mg/L NO(3)-N with effluent sulfate concentration of around 225 mg/L was achieved when methanol was supplemented at methanol/NO(3)-N ratio of 1.67 (mg/mg), which was much lower than the theoretical value of 2.47 for heterotrophic denitrification. Batch studies showed that sulfur-based autotrophic NO(2)-N reduction rate was around three times lower than the reduction rate of NO(3)-N, which led to NO(2)-N accumulation at high loadings. Copyright © 2011 Elsevier Ltd. All rights reserved.

Laboratory estimates of trace gas emissions following surface application and injection of cattle slurry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flessa, H.; Beese, F.

2000-02-01

Applying cattle slurry to soil may induce emissions of the greenhouse gases N{sub 2}O and CH{sub 4}. Their objective was to determine the effects of different application techniques (surface application and slit injection) of cattle (Bostaurus) slurry on the decomposition of slurry organic matter and the emissions of N{sub 2}O and CH{sub 4}. The effects of slurry application (43.6 m{sup 3} ha{sup {minus}1}) were studied for 9 wk under controlled laboratory conditions using a soil microcosm system with automated monitoring of the CO{sub 2}, N{sub 2}O, and CH{sub 4} fluxes. The soil used was a silty loam (Ap horizon ofmore » a cambisol) with a constant water-filled pore space of 67% during the experiment. About 38% of the organic matter applied with the slurry was decomposed within 9 wk. Production of CO{sub 2} was not affected by the application technique. Emissions of N{sub 2}O and CH{sub 4} from the injected slurry were significantly higher than from the surface-applied slurry, probably because of restricted aeration at the injected-slurry treatment. Total N{sub 2}O-N emissions were 0.2% (surface application) and 3.3% (slit injection) of the slurry N added. Methane emission occurred only during the first few days following application. The total net flux of CH{sub 4}-C for 2 wk was {minus}12 g ha{sup {minus}1} for the control (CH{sub 4} uptake), 2 g ha{sup {minus}1} for the surface-applied slurry, and 39 g ha{sup {minus}1} for the injected slurry. Slurry injection, which is recommended to reduce NH{sub 3} volatilization, appears to increase emissions of the greenhouse gases N{sub 2}O and CH{sub 4} from the fertilized fields.« less

PEP Support Laboratory Leaching and Permeate Stability Tests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Russell, Renee L.; Peterson, Reid A.; Rinehart, Donald E.

2009-09-25

Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed, and operated as part of a plan to respond to issue M12, "Undemonstrated Leaching Processes," of the External Flowsheet Review Team (EFRT) issue response plan.( ) The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes.more » The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. A simplified flow diagram of the PEP system is shown in Figure 1.1. Two operating scenarios are currently being evaluated for the ultrafiltration process (UFP) and leaching operations. The first scenario has caustic leaching performed in the UFP-2 ultrafiltration feed vessels (i.e., vessel UFP-VSL-T02A in the PEP and vessels UFP-VSL-00002A and B in the WTP PTF). The second scenario has caustic leaching conducted in the UFP-1 ultrafiltration feed preparation vessels (i.e., vessels UFP-VSL-T01A and B in the PEP and vessels UFP-VSL-00001A and B in the WTP PTF). In both scenarios, 19-M sodium hydroxide solution (NaOH, caustic) is added to the waste slurry in the vessels to leach solid aluminum compounds (e.g., gibbsite, boehmite). Caustic addition is followed by a heating step that uses direct injection of steam to accelerate the leach process. Following the caustic leach, the vessel contents are cooled using vessel cooling jackets and/or external heat exchangers. The main difference between the two scenarios is that for leaching in UFP-VSL-T01A and B, the 19-M NaOH is added to un-concentrated waste slurry (3 to 8 wt% solids), while for leaching in UFP-VSL-T02A, the slurry is concentrated to nominally 20 wt% solids using cross-flow ultrafiltration before adding caustic.« less

Monetization of Nigeria coal by conversion to hydrocarbon fuels through Fischer-Tropsch process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oguejiofor, G.C.

Given the instability of crude oil prices and the disruptions in crude oil supply chains, this article offers a complementing investment proposal through diversification of Nigeria's energy source and dependence. Therefore, the following issues were examined and reported: A comparative survey of coal and hydrocarbon reserve bases in Nigeria was undertaken and presented. An excursion into the economic, environmental, and technological justifications for the proposed diversification and roll-back to coal-based resource was also undertaken and presented. The technology available for coal beneficiation for environmental pollution control was reviewed and reported. The Fischer-Tropsch synthesis and its advances into Sasol's slurry phasemore » distillate process were reviewed. Specifically, the adoption of Sasol's advanced synthol process and the slurry phase distillate process were recommended as ways of processing the products of coal gasification. The article concludes by discussing all the above-mentioned issues with regard to value addition as a means of wealth creation and investment.« less

Effects of limestone on starch digestion in Holstein steers.

PubMed

Tissera, G H; Vandersall, J H; Erdman, R A

1988-03-01

Eight calcitic and three dolomitic limestones were examined for particle size and reactivity with hydrochloric acid at pH 3.5 and 5.5. Reactivity was higher in calcitic than dolomitic limestone. Within calcitic limestones, reactivity was highly related to particle size. A highly reactive limestone was selected for use in two digestion trials with Holstein steers. In Trial 1, 4 steers (approximately 300 kg) were fed diets consisting of 40% corn silage and 60% concentrate (DM basis) with .62 or 2.34% limestone in a single reversal trial with 3-wk experimental periods. Added limestone affected only starch digestibility, which increased from 91.3 to 93.2%. Fecal pH increased from 5.7 to 6.4 by limestone addition. In trial 2, four rumen and duodenally cannulated steers (approximately 475 kg) were fed the same diets in the same design. Limestone addition increased fecal pH from 5.7 to 6.5. There were no effects of limestone on rumen or total tract digestion of starch or other nutrients. Limestone addition had no effect on rumen pH, buffering capacity, or VFA concentrations. Addition of a highly reactive limestone to diets containing high amounts of starch had little effect on starch digestion in either the rumen or lower gastrointestinal tract.

Acid processing of pre-Tertiary radiolarian cherts and its impact on faunal content and biozonal correlation

USGS Publications Warehouse

Blome, C.D.; Reed, K.M.

1993-01-01

Destruction of radiolarians during both diagenesis and HF processing severely reduces faunal abundance and diversity and affects the taxonomic and biostratigraphic utility of chert residues. The robust forms that survive the processing represent only a small fraction of the death assemblage, and delicate skeletal structures used for species differentiation, are either poorly preserved or dissolved in many coeval chert residues. First and last occurrences of taxa in chert sequences are likely to be coarse approximations of their true stratigraphic ranges. Precise correlation is difficult between biozonations based solely on index species from cherts and those constructed from limestone faunas. Careful selection of samples in sequence, use of weaker HF solutions, and study of both chert and limestone faunas should yield better biostratigraphic information. -from Authors

Mechanical and chemical compaction in fine-grained shallow-water limestones.

USGS Publications Warehouse

Shinn, E.A.; Robbin, D.M.

1983-01-01

Significant mechanical compaction resulted from pressures simulating less than 305 m of burial. Increasing loads to an equivalent of more than 3400 m did not significantly increase compaction or reduce sediment core length. Chemical compaction (pressure dissolution) was detected only in sediment cores compacted to pressures greater than 3400 m of burial. These short-term experiments suggest that chemical compaction would begin at much shallower depths given geologic time. Compaction experiments that caused chemical compaction lend support to the well-established hypothesis; that cement required to produce a low-porosity/low-permeability fine-grained limestone is derived internally. Dissolution, ion diffusion, and reprecipitation are considered the most likely processes for creating significant thicknesses of dense limestone in the geologic record. Continuation of chemical compaction after significant porosity reduction necessitates expulsion of connate fluids, possibly including hydrocarbons. -from Authors

Submerged beachrock preservation in the context of wave ravinement

NASA Astrophysics Data System (ADS)

Pretorius, Lauren; Green, Andrew N.; Andrew Cooper, J.

2018-02-01

This study examines a Holocene-aged submerged shoreline, Limestone Reef, located in the shallow subtidal zone of South Africa's east coast. It comprises an elongate, coast-oblique, slab-like outcrop of beachrock situated above the contemporary fair-weather wave base. It is currently undergoing mechanical disintegration. Its unique and rare preservation in a high-energy setting affords an opportunity to examine the mechanical processes occurring during wave ravinement associated with rising sea level. The submerged shoreline and the adjacent shoreface were examined using high-resolution seismic reflection, side-scan sonar and shallow-water multibeam echosounding techniques. Limestone Reef rests on top of unconsolidated Holocene deposits. The structure's surface is characterised by reef-perpendicular gullies with rubble derived from the slab fringing its seaward edge. Limestone Reef slopes gently seawards and has a steep landward-facing edge where gullies are most prominently developed. Teardrop-shaped rippled scour depressions, marked by high backscatter, are located seawards of the submerged shoreline. These elongate in a seaward direction and are filled with bioclastic gravels and residual rubble from Limestone Reef. The gullies in the upstanding structure are indicative of wave plucking and abrasion of the shoreline. The material exposed by the rippled scour depressions is identical to that comprising the postglacial ravinement surface identified in the offshore stratigraphy. These deposits are considered to represent the contemporary, actively forming wave ravinement surface. The results suggest that wave ravinement of submerged shorelines is a discontinuous process dominated by the seaward entrainment of material from its landward edge controlled by high-energy drawback during storm surges. The ravinement process appears to operate at the seasonal scale and averages out over the long-term millennial scale for the continuous surface.

46 CFR Table 2 to Part 153 - Cargoes Not Regulated Under Subchapters D or O of This Chapter When Carried in Bulk on Non...

Code of Federal Regulations, 2013 CFR

2013-10-01

...-ethylamino-6-isopropylamino-5-triazine solution # Choline chloride solution D Clay slurry III Coal slurry III... acid, dimethylamine salt solution * Y Choline chloride solutions Z Clay slurry OS Coal slurry OS...

Modified starch containing liquid fuel slurry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Metzger, G.W.

1978-04-04

A substantially water-free, high solids content, stably dispersed combustible fuel slurry is provided, with a method of preparing the slurry. The slurry contains a minor amount of a solid particulate carbonaceous material such as powdered coal, with substantially the entire balance of the slurry being comprised of a liquid hydrocarbon fuel, particularly a heavy fuel oil. In extremely minor amounts are anionic surfactants, particularly soaps, and a stabilizing amount of a starch modified with an anionic polymer.

Effect of organized assemblies. Part 4. Formulation of highly concentrated coal-water slurry using a natural surfactant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Debadutta Das; Sagarika Panigrahi; Pramila K. Misra

2008-05-15

Coal-water slurry has received considerable research nowadays due to its ability in substituting energy sources. The present work reports the formulation of highly concentrated coal-water slurry using a natural occurring surface active compound, saponin, extracted from the fruits of plant Sapindous laurifolia. The isolation of saponin from the plant and its surface activity has been discussed. The rheological characteristics of coal-water slurry have been investigated as a function of coal loading, ash content of coal, pH, temperature, and amount of saponin. The viscosity of the slurry and zeta potential are substantially decreased with concomitant shift of the isoelectric point ofmore » coal on adsorption of saponin to it. In the presence of 0.8% of saponin, coal-water slurry containing 64% weight fraction of coal could be achieved. The slurry is stable for a period of as long as 1 month in contrast to 4-5 h in the case of bare coal-water slurry. The results confirm the use of saponin as a suitable additive for coal-water slurry similar to the commercially available additive such as sodium dodecyl sulfate. Basing on the effect of pH on the zeta potential and viscosity of slurry, a suitable mechanism for saponin-coal interaction and orientation of saponin at the coal-water interface has been proposed. 47 refs., 12 figs., 5 tabs.« less

A Simple Criterion to Estimate Performance of Pulse Jet Mixed Vessels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pease, Leonard F.; Bamberger, Judith A.; Mahoney, Lenna A.

Pulse jet mixed process vessels comprise a key element of the U.S. Department of Energy’s strategy to process millions of gallons of legacy nuclear waste slurries. Slurry suctioned into a pulse jet mixer (PJM) tube at the end of one pulse is pneumatically driven from the PJM toward the bottom of the vessel at the beginning of the next pulse, forming a jet. The jet front traverses the distance from nozzle outlet to the bottom of the vessel and spreads out radially. Varying numbers of PJMs are typically arranged in a ring configuration within the vessel at a selected radiusmore » and operated concurrently. Centrally directed radial flows from neighboring jets collide to create a central upwell that elevates the solids in the center of the vessel when the PJM tubes expel their contents. An essential goal of PJM operation is to elevate solids to the liquid surface to minimize stratification. Solids stratification may adversely affect throughput of the waste processing plant. Unacceptably high slurry densities at the base of the vessel may plug the pipeline through which the slurry exits the vessel. Additionally, chemical reactions required for processing may not achieve complete conversion. To avoid these conditions, a means of predicting the elevation to which the solids rise in the central upwell that can be used during vessel design remains essential. In this paper we present a simple criterion to evaluate the extent of solids elevation achieved by a turbulent upwell jet. The criterion asserts that at any location in the central upwell the local velocity must be in excess of a cutoff velocity to remain turbulent. We find that local velocities in excess of 0.6 m/s are necessary for turbulent jet flow through both Newtonian and yield stress slurries. By coupling this criterion with the free jet velocity equation relating the local velocity to elevation in the central upwell, we estimate the elevation at which turbulence fails, and consequently the elevation at which the upwell fails to further lift the slurry. Comparing this elevation to the vessel fill level predicts whether the jet flow will achieve the full vertical extent of the vessel at the center. This simple local-velocity criterion determines a minimum PJM nozzle velocity at which the full vertical extent of the central upwell in PJM vessels will be turbulent. The criterion determines a minimum because flow in regions peripheral to the central upwelling jet may not be turbulent, even when the center of the vessel in the upwell is turbulent, if the jet pulse duration is too short. The local-velocity criterion ensures only that there is sufficient wherewithal for the turbulent jet flow to drive solids to the surface in the center of the vessel in the central upwell.« less

Solubility of Plutonium (IV) Oxalate During Americium/Curium Pretreatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rudisill, T.S.

1999-08-11

Approximately 15,000 L of solution containing isotopes of americium and curium (Am/Cm) will undergo stabilization by vitrification at the Savannah River Site (SRS). Prior to vitrification, an in-tank pretreatment will be used to remove metal impurities from the solution using an oxalate precipitation process. Material balance calculations for this process, based on solubility data in pure nitric acid, predict approximately 80 percent of the plutonium in the solution will be lost to waste. Due to the uncertainty associated with the plutonium losses during processing, solubility experiments were performed to measure the recovery of plutonium during pretreatment and a subsequent precipitationmore » process to prepare a slurry feed for a batch melter. A good estimate of the plutonium content of the glass is required for planning the shipment of the vitrified Am/Cm product to Oak Ridge National Laboratory (ORNL).The plutonium solubility in the oxalate precipitation supernate during pretreatment was 10 mg/mL at 35 degrees C. In two subsequent washes with a 0.25M oxalic acid/0.5M nitric acid solution, the solubility dropped to less than 5 mg/mL. During the precipitation and washing steps, lanthanide fission products in the solution were mostly insoluble. Uranium, and alkali, alkaline earth, and transition metal impurities were soluble as expected. An elemental material balance for plutonium showed that greater than 94 percent of the plutonium was recovered in the dissolved precipitate. The recovery of the lanthanide elements was generally 94 percent or higher except for the more soluble lanthanum. The recovery of soluble metal impurities from the precipitate slurry ranged from 15 to 22 percent. Theoretically, 16 percent of the soluble oxalates should have been present in the dissolved slurry based on the dilution effects and volumes of supernate and wash solutions removed. A trace level material balance showed greater than 97 percent recovery of americium-241 (from the beta dec ay of plutonium-241) in the dissolved precipitate, a value consistent with the recovery of europium, the americium surrogate.In a subsequent experiment, the plutonium solubility following an oxalate precipitation to simulate the preparation of a slurry feed for a batch melter was 21 mg/mL at 35 degrees C. The increase in solubility compared to the value measured during the pretreatment experiment was attributed to the increased nitrate concentration and ensuing increase in plutonium complexation. The solubility of the plutonium following a precipitant wash with 0.1M oxalic acid was unchanged. The recovery of plutonium from the precipitate slurry was greater than 97 percent allowing an estimation that approximately 92 percent of the plutonium in Tank 17.1 will report to the glass. The behavior of the lanthanides and soluble metal impurities was consistent with the behavior seen during the pretreatment experiment. A trace level material balance showed that 99.9 percent of the americium w as recovered from the precipitate slurry. The overall recovery of americium from the pretreatment and feed preparation processes was greater than 97 percent, which was consistent with the measured recovery of the europium surrogate.« less

METHOD FOR THE PREPARATION OF STABLE ACTINIDE METAL OXIDE-CONTAINING SLURRIES AND OF THE OXIDES THEREFOR

DOEpatents

Hansen, R.S.; Minturn, R.E.

1958-02-25

This patent deals with a method of preparing actinide metal oxides of a very fine particle size and of forming stable suspensions therefrom. The process consists of dissolving the nitrate of the actinide element in a combustible organic solvent, converting the solution obtained into a spray, and igniting the spray whereby an oxide powder is obtained. The oxide powder is then slurried in an aqueous soiution of a substance which is adsorbable by said oxides, dspersed in a colloid mill whereby a suspension is obtained, and electrodialyzed until a low spectiic conductance is reached.

Efficient process for previous metal recovery from cell membrane electrode assemblies

DOEpatents

Shore, Lawrence; Matlin, Ramail; Heinz, Robert

2010-05-04

A method is provided for recovering a catalytic element from a fuel cell membrane electrode assembly. The method includes grinding the membrane electrode assembly into a powder, extracting the catalytic element by forming a slurry comprising the powder and an acid leachate adapted to dissolve the catalytic element into a soluble salt, and separating the slurry into a depleted powder and a supernatant containing the catalytic element salt. The depleted powder is washed to remove any catalytic element salt retained within pores in the depleted powder and the catalytic element is purified from the salt.

Stereolithography: A new method for processing dental ceramics by additive computer-aided manufacturing.

PubMed

Dehurtevent, Marion; Robberecht, Lieven; Hornez, Jean-Christophe; Thuault, Anthony; Deveaux, Etienne; Béhin, Pascal

2017-05-01

The aim of this study was to compare the physical and mechanical properties of stereolithography (SLA)- manufactured alumina ceramics of different composition to those of subtractive- manufactured ceramics and to produce suitable dental crown frameworks. The physical and mechanical properties of a control and six experimental SLA ceramics prepared from slurries with small (S) and large (L) particles (0.46±0.03 and 1.56±0.04μm, respectively) and three dry matter contents (70%, 75%, 80%) were evaluated by dynamic rheometry, hydrostatic weighing, three3-point flexural strength measurements, and Weibull analyses, and by the micrometrics measurement of shrinkage ratio before and after the heat treatments. S75 was the only small particle slurry with a significantly higher viscosity than L70. The viscosity of the S80 slurry made it impossible to take rheological measurements. The viscosities of the S75 and S80 slurries caused deformations in the printed layers during SLA manufacturing and were excluded from further consideration. SLA samples with low dry matter content had significantly lower and densityflexural strengths. Only SLA samples with a large particle size and high dry matter content (L75 and L80) were similar in density and flexural strength to the subtractive- manufactured samples. The 95% confidence intervals of the Weibull modulus of the L80 ceramic were higher (no overlap fraction) than those of the L75 ceramic and were similar to the control (overlap fraction). The Weibull characteristics of L80 ceramic were higher than those of L75 ceramic and the control. SLA can be used to process suitable crown frameworks but shows results in anisotropic shrinkage. The hH High particle size and dry matter content of the L80 slurry allowed made it possible to produce a reliable ceramic by SLA manufacturing with an anisotropic shrinkage, and a density, and flexural strength similar to those of a subtractive-manufactured ceramic. SLA allowed made it possible to build up a dense 3D alumina crown framework with controlled shape. Further studies on the marginal adaptation and shrinkage model of alumina crown frameworks will be required to optimize the process. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Influence of Specific Surface of Lignite Fluidal Ashes on Rheological Properties of Sealing Slurries / Wpływ Powierzchni Właściwej Popiołów Fluidalnych z Węgla Brunatnego na Właściwości Reologiczne Zaczynów Uszczelniających

NASA Astrophysics Data System (ADS)

Stryczek, Stanisław; Wiśniowski, Rafał; Gonet, Andrzej; Złotkowski, Albert

2012-11-01

New generation fly ashes come from the combustion of coal in fluid-bed furnaces with simultaneous sulphur-removal from gases at ca. 850°C. Accordingly, all produced ashes basically differ in their physicochemical properties from the traditional silica ones. The aim of the laboratory analyses was determining the influence of specific surface and granular composition of fluidal ash on rheological properties of slurries used for sealing up the ground and rock mass media with hole injection methods, geoengineering works and cementing casing pipes in deep boreholes. Fluidal ash from the combustion of lignite contain active Puzzolan appearing in the form of dehydrated clayey minerals and active components activating the process of hydration ashes, i.e. CaO, anhydrite II and CaCO3. The ashes have a weak point, i.e. their high water diment, which the desired rheological properties related with the range of their propagation in the rock mass cannot not be acquired for injection works in the traditional sealing slurries technology. Increasing the water-to-mixture ratio should eliminate this feature of fluidal ashes. Laboratory analyses were performed for slurries based on metallurgical cement CEM III/A 32,5 having water-to-mixture ratios: 0.5; 0.6 ; 0.7 and 0.8; the fluidal ash concentration in the slurries was 30 wt.% (with respect to the mass of dry cement). Basing on the obtained results there were determined optimum recipes of sealing slurries in view of their rheological parameters which could be applied both in drilling technologies (cementing casing pipes, closing of boreholes, plugging) and in geoengineering works related with sealing up and reinforcing ground and rock mass media.

Formulation of low solids coal water slurry from advanced coal cleaning waste fines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Battista, J.J.; Morrison, J.L.; Lambert, A.

1997-07-01

GPU Genco, the New York State Electric and Gas Corporation (NYSEG), Penn State University and the Homer City Coal Processing Corporation are conducting characterization and formulation tests to determine the suitability of using minus 325 mesh coal waste fines as a low solids coal water slurry (CWS) co-firing fuel. The fine coal is contained in a centrifuge effluent stream at the recently modified Homer City Coal Preparation Plant. Recovering, thickening and then co-firing this material with pulverized coal is one means of alleviating a disposal problem and increasing the Btu recovery for the adjacent power plant. The project team ismore » currently proceeding with the design of a pilot scale system to formulate the effluent into a satisfactory co-firing fuel on a continuous basis for combustion testing at Seward Station. The ultimate goal is to burn the fuel at the pulverized coal units at the Homer City Generating Station. This paper presents the success to date of the slurry characterization and pilot scale design work. In addition, the paper will update GPU Genco`s current status for the low solids coal water slurry co-firing technology and will outline the company`s future plans for the technology.« less

Scalable Dry Printing Manufacturing to Enable Long-Life and High Energy Lithium-Ion Batteries

DOE PAGES

Liu, Jin; Ludwig, Brandon; Liu, Yangtao; ...

2017-08-22

Slurry casting method dominates the electrode manufacture of lithium-ion batteries. The entire procedure is similar to the newspaper printing that includes premixing of cast materials into solvents homogeneously, and continuously transferring and drying the slurry mixture onto the current collector. As a market approaching US $80 billion by 2024, the optimization of manufacture process is crucial and attractive. However, the organic solvent remains irreplaceable in the wet method for making slurries, even though it is capital-intensive and toxic. In this paper, an advanced powder printing technique is demonstrated that is completely solvent-free and dry. Through removing the solvent and relatedmore » procedures, this method is anticipated to statistically save 20% of the cost at a remarkably shortened production cycle (from hours to minutes). The dry printed electrodes outperform commercial slurry cast ones in 650 cycles (80% capacity retention in 500 cycles), and thick electrodes are successfully fabricated to increase the energy density. Furthermore, microscopy techniques are utilized to characterize the difference of electrode microstructure between dry and wet methods, and distinguish dry printing's advantages on controlling the microstructure. Finally, this study proves a practical fabrication method for lithium-ion electrodes with lowered cost and favorable performance, and allows more advanced electrode designs potentially.« less

Scalable Dry Printing Manufacturing to Enable Long-Life and High Energy Lithium-Ion Batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Jin; Ludwig, Brandon; Liu, Yangtao

Slurry casting method dominates the electrode manufacture of lithium-ion batteries. The entire procedure is similar to the newspaper printing that includes premixing of cast materials into solvents homogeneously, and continuously transferring and drying the slurry mixture onto the current collector. As a market approaching US $80 billion by 2024, the optimization of manufacture process is crucial and attractive. However, the organic solvent remains irreplaceable in the wet method for making slurries, even though it is capital-intensive and toxic. In this paper, an advanced powder printing technique is demonstrated that is completely solvent-free and dry. Through removing the solvent and relatedmore » procedures, this method is anticipated to statistically save 20% of the cost at a remarkably shortened production cycle (from hours to minutes). The dry printed electrodes outperform commercial slurry cast ones in 650 cycles (80% capacity retention in 500 cycles), and thick electrodes are successfully fabricated to increase the energy density. Furthermore, microscopy techniques are utilized to characterize the difference of electrode microstructure between dry and wet methods, and distinguish dry printing's advantages on controlling the microstructure. Finally, this study proves a practical fabrication method for lithium-ion electrodes with lowered cost and favorable performance, and allows more advanced electrode designs potentially.« less

Process for Making Ceramic Mold

NASA Technical Reports Server (NTRS)

Buck, Gregory M. (Inventor); Vasquez, Peter (Inventor)

2001-01-01

An improved process for slip casting molds that can be more economically automated and that also exhibits greater dimensional stability is disclosed. The process involves subjecting an investment pattern, preferably made from wax, to successive cycles of wet-dipping in a slurry of colloidal, silica-based binder and dry powder-coating, or stuccoing with plaster of Paris or calcium sulfate mixtures to produce a multi-layer shell over the pattern. The invention as claimed entails applying a primary and a secondary coating to the investment pattern. At least two wet-dipping on in a primary slurry and dry-stuccoing cycles provide the primary coating, and an additional two wet-dippings and dry-stuccoing cycles provide the secondary, or back-up, coating. The primary and secondary coatings produce a multi-layered shell pattern. The multi-layered shell pattern is placed in a furnace first to cure and harden, and then to vaporize the investment pattern, leaving a detailed, high precision shell mold.

Rheometry of natural sediment slurries

USGS Publications Warehouse

Major, Jon J.; ,

1993-01-01

Recent experimental analyses of natural sediment slurries yield diverse results yet exhibit broad commonality of rheological responses under a range of conditions and shear rates. Results show that the relation between shear stress and shear rate is primarily nonlinear, that the relation can display marked hysteresis, that minimum shear stress can occur following yield, that physical properties of slurries are extremely sensitive to sediment concentration, and the concept of slurry yield strength is still debated. New rheometric analyses have probed viscoelastic behavior of sediment slurries. Results show that slurries composed of particles ??? 125 ?? m exhibit viscoelastic responses, and that shear stresses are relaxed over a range of time scales rather than by a single response time.

DEHYDRATION OF DEUTERIUM OXIDE SLURRIES

DOEpatents

Hiskey, C.F.

1959-03-10

A method is presented for recovering heavy water from uranium oxide-- heavy water slurries. The method consists in saturating such slurries with a potassium nitrate-sodium nitrate salt mixture and then allowing the self-heat of the slurry to raise its temperature to a point slightly in excess of 100 deg C, thus effecting complete evaporation of the free heavy water from the slurry. The temperature of the slurry is then allowed to reach 300 to 900 deg C causing fusion of the salt mixture and expulsion of the water of hydration. The uranium may be recovered from the fused salt mixture by treatment with water to leach the soluble salts away from the uranium-containing residue.

Fuel injection of coal slurry using vortex nozzles and valves

DOEpatents

Holmes, Allen B.

1989-01-01

Injection of atomized coal slurry fuel into an engine combustion chamber is achieved at relatively low pressures by means of a vortex swirl nozzle. The outlet opening of the vortex nozzle is considerably larger than conventional nozzle outlets, thereby eliminating major sources of failure due to clogging by contaminants in the fuel. Control fluid, such as air, may be used to impart vorticity to the slurry and/or purge the nozzle of contaminants during the times between measured slurry charges. The measured slurry charges may be produced by a diaphragm pump or by vortex valves controlled by a separate control fluid. Fluidic circuitry, employing vortex valves to alternatively block and pass cool slurry fuel flow, is disclosed.

Method for stabilizing low-level mixed wastes at room temperature

DOEpatents

Wagh, A.S.; Singh, D.

1997-07-08

A method to stabilize solid and liquid waste at room temperature is provided comprising combining solid waste with a starter oxide to obtain a powder, contacting the powder with an acid solution to create a slurry, said acid solution containing the liquid waste, shaping the now-mixed slurry into a predetermined form, and allowing the now-formed slurry to set. The invention also provides for a method to encapsulate and stabilize waste containing cesium comprising combining the waste with Zr(OH){sub 4} to create a solid-phase mixture, mixing phosphoric acid with the solid-phase mixture to create a slurry, subjecting the slurry to pressure; and allowing the now pressurized slurry to set. Lastly, the invention provides for a method to stabilize liquid waste, comprising supplying a powder containing magnesium, sodium and phosphate in predetermined proportions, mixing said powder with the liquid waste, such as tritium, and allowing the resulting slurry to set. 4 figs.

Method for stabilizing low-level mixed wastes at room temperature

DOEpatents

Wagh, Arun S.; Singh, Dileep

1997-01-01

A method to stabilize solid and liquid waste at room temperature is provided comprising combining solid waste with a starter oxide to obtain a powder, contacting the powder with an acid solution to create a slurry, said acid solution containing the liquid waste, shaping the now-mixed slurry into a predetermined form, and allowing the now-formed slurry to set. The invention also provides for a method to encapsulate and stabilize waste containing cesium comprising combining the waste with Zr(OH).sub.4 to create a solid-phase mixture, mixing phosphoric acid with the solid-phase mixture to create a slurry, subjecting the slurry to pressure; and allowing the now pressurized slurry to set. Lastly, the invention provides for a method to stabilize liquid waste, comprising supplying a powder containing magnesium, sodium and phosphate in predetermined proportions, mixing said powder with the liquid waste, such as tritium, and allowing the resulting slurry to set.

Enhancing protein to extremely high content in photosynthetic bacteria during biogas slurry treatment.

PubMed

Yang, Anqi; Zhang, Guangming; Meng, Fan; Lu, Pei; Wang, Xintian; Peng, Meng

2017-12-01

This work proposed a novel approach to achieve an extremely high protein content in photosynthetic bacteria (PSB) using biogas slurry as a culturing medium. The results showed the protein content of PSB could be enhanced strongly to 90% in the biogas slurry, which was much higher than reported microbial protein contents. The slurry was partially purified at the same time. Dark-aerobic was more beneficial than light-anaerobic condition for protein accumulation. High salinity and high ammonia of the biogas slurry were the main causes for protein enhancement. In addition, the biogas slurry provided a good buffer system for PSB to grow. The biosynthesis mechanism of protein in PSB was explored according to theoretical analysis. During biogas slurry treatment, the activities of glutamate synthase and glutamine synthetase were increased by 26.55%, 46.95% respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Experimental study on the application of paraffin slurry to high density electronic package cooling

NASA Astrophysics Data System (ADS)

Cho, K.; Choi, M.

Experiments were performed by using water and paraffin slurry to investigate thermal characteristics from a test multichip module. The parameters were the mass fraction of paraffin slurry (0, 2.5, 5, 7.5%), heat flux (10, 20, 30, 40W/cm2) and channel Reynolds numbers. The size of paraffin slurry particles was within 10-40μm. The local heat transfer coefficients for the paraffin slurry were larger than those for water. Thermally fully developed conditions were observed after the third or fourth row. The paraffin slurry with a mass fraction of 5% showed the most efficient cooling performance when the heat transfer and the pressure drop in the test section were considered simultaneously. A new correlation for the water and the paraffin slurry with a mass fraction of 5% was obtained for a channel Reynolds number over 5300.

Drilling Holes in Graphite/Epoxy Composites

NASA Technical Reports Server (NTRS)

Daniels, J. G.; Ledbetter, Frank E., III; Penn, B. G.; White, W. L.

1986-01-01

Slurry of silicon carbide powder in water fed onto bit while drilling. Slurry contains about 60 percent silicon carbide by weight. Slurry recirculated by low-power pump. With slurry, dull tools cut as fast as, or faster than, sharp ones. Holes drilled rapidly and efficiently regardless of ply orientation; whether unidirectional, quasi-isotropic symmetrical, or cross-ply.

30 CFR 77.216 - Water, sediment, or slurry impoundments and impounding structures; general.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Water, sediment, or slurry impoundments and... WORK AREAS OF UNDERGROUND COAL MINES Surface Installations § 77.216 Water, sediment, or slurry... structures which impound water, sediment, or slurry shall be required if such an existing or proposed...

30 CFR 77.216 - Water, sediment, or slurry impoundments and impounding structures; general.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Water, sediment, or slurry impoundments and... WORK AREAS OF UNDERGROUND COAL MINES Surface Installations § 77.216 Water, sediment, or slurry... structures which impound water, sediment, or slurry shall be required if such an existing or proposed...

CATALYTIC RECOMBINATION OF RADIOLYTIC GASES IN THORIUM OXIDE SLURRIES

DOEpatents

Morse, L.E.

1962-08-01

A method for the coinbination of hydrogen and oxygen in aqueous thorium oxide-uranium oxide slurries is described. A small amount of molybdenum oxide catalyst is provided in the slurry. This catalyst is applicable to the recombination of hydrogen and/or deuterium and oxygen produced by irradiation of the slurries in nuclear reactors. (AEC)

Rheological Behavior and Microstructure of Ceramic Particulate/Aluminum Alloy Composites. Ph.D. Thesis Final Technical Report

NASA Technical Reports Server (NTRS)

Moon, Hee-Kyung

1990-01-01

The rheological behavior and microstructure were investigated using a concentric cylinder viscometer for three different slurries: semi-solid alloy slurries of a matrix alloy, Al-6.5wt percent Si: composite slurries, SiC (sub p) (8.5 microns)/Al-6.5wt percent Si, with the same matrix alloy in the molten state, and composite slurries of the same composition with the matrix alloy in the semi-solid state. The pseudoplasticity of these slurries was obtained by step changes of the shear rate from a given initial shear rate. To study the thixotropic behavior of the system, a slurry was allowed to rest for different periods of time, prior to shearing at a given initial shear rate. In the continuous cooling experiments, the viscosities of these slurries were dependent on the shear rate, cooling rate, volume fraction of the primary solid of the matrix alloy, and volume fraction of silicon carbide. In the isothermal experiments, all three kinds of slurries exhibited non-Newtonian behavior, depending on the volume fraction of solid particles.

21 CFR 184.1461 - Manganese sulfate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... hydroquinone. Other manufacturing processes include the action of sulfur dioxide on a slurry of manganese..., followed by leaching and crystallization. (b) The ingredient meets the specifications of the Food Chemicals...

21 CFR 184.1461 - Manganese sulfate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... hydroquinone. Other manufacturing processes include the action of sulfur dioxide on a slurry of manganese..., followed by leaching and crystallization. (b) The ingredient meets the specifications of the Food Chemicals...

Study on the influence of the decoking agent on the activity of limestone in wet flue gas desulfurization

NASA Astrophysics Data System (ADS)

Li, Qianjun; Xu, Dongyang; Wu, Yunxia; Yu, Jin

2017-01-01

Influence of the main components of decoking agent (magnesium nitrate, aluminum nitrate, copper nitrate, ammonium nitrate and actual decoking agent) on the activity of limestone is studied in laboratory by MET method. Results show that magnesium nitrate, ammonium nitrate and copper nitrate almost has no effect on the activity of limestone. With the concentration increasing, aluminum nitrate has an increasing inhibition on the dissolution of limestone. Fly ash has inhibition on dissolution of limestone due to the blockage of limestone pore by fly ash. The actual decoking agent has almost no effect on the limestone.

Interactions between soil texture and placement of dairy slurry application: I. Flow characteristics and leaching of nonreactive components.

PubMed

Glaesner, Nadia; Kjaergaard, Charlotte; Rubaek, Gitte H; Magid, Jakob

2011-01-01

Land application of manure can exacerbate nutrient and contaminant transfers to the aquatic environment. This study examined the effect of injecting a dairy cattle (Bostaurus L.) manure slurry on mobilization and leaching of dissolved, nonreactive slurry components across a range of agricultural soils. We compared leaching of slurry-applied bromide through intact soil columns (20 cm diam., 20 cm high) of differing textures following surface application or injection of slurry. The volumetric fraction of soil pores >30 microm ranged from 43% in a loamy sand to 28% in a sandy loam and 15% in a loam-textured soil. Smaller active flow volumes and higher proportions of preferential flow were observed with increasing soil clay content. Injection of slurry in the loam soil significantly enhanced diffusion of applied bromide into the large fraction of small pores compared with surface application. The resulting physical protection against leaching of bromide was reflected by 60.2% of the bromide tracer was recovered in the effluent after injection, compared with 80.6% recovery after surface application. No effect of slurry injection was observed in the loamy sand and sandy loam soils. Our findings point to soil texture as an important factor influencing leaching of dissolved, nonreactive slurry components in soils amended with manure slurry.

Electrode Slurry Particle Density Mapping Using X-ray Radiography

DOE PAGES

Higa, Kenneth; Zhao, Hui; Parkinson, Dilworth Y.; ...

2017-01-05

The internal structure of a porous electrode strongly influences battery performance. Understanding the dynamics of electrode slurry drying could aid in engineering electrodes with desired properties. For instance, one might monitor the dynamic, spatially-varying thickness near the edge of a slurry coating, as it should lead to non-uniform thickness of the dried film. This work examines the dynamic behavior of drying slurry drops consisting of SiO x and carbon black particles in a solution of carboxymethylcellulose and deionized water, as an experimental model of drying behavior near the edge of a slurry coating. An X-ray radiography-based procedure is developed tomore » calculate the evolving spatial distribution of active material particles from images of the drying slurry drops. To the authors’ knowledge, this study is the first to use radiography to investigate battery slurry drying, as well as the first to determine particle distributions from radiography images of drying suspensions. The dynamic results are consistent with tomography reconstructions of the static, fully-dried films. It is found that active material particles can rapidly become non-uniformly distributed within the drops. Heating can promote distribution uniformity, but seemingly must be applied very soon after slurry deposition. Higher slurry viscosity is found to strongly restrain particle redistribution.« less

Effects of cattle-slurry treatment by acidification and separation on nitrogen dynamics and global warming potential after surface application to an acidic soil.

PubMed

Fangueiro, David; Pereira, José; Bichana, André; Surgy, Sónia; Cabral, Fernanda; Coutinho, João

2015-10-01

Cattle-slurry (liquid manure) application to soil is a common practice to provide nutrients and organic matter for crop growth but it also strongly impacts the environment. The objective of the present study was to assess the efficiency of cattle-slurry treatment by solid-liquid separation and/or acidification on nitrogen dynamics and global warming potential (GWP) following application to an acidic soil. An aerobic laboratory incubation was performed over 92 days with a Dystric Cambisol amended with raw cattle-slurry or separated liquid fraction (LF) treated or not by acidification to pH 5.5 by addition of sulphuric acid. Soil mineral N contents and NH3, N2O, CH4 and CO2 emissions were measured. Results obtained suggest that the acidification of raw cattle-slurry reduced significantly NH3 emissions (-88%) but also the GWP (-28%) while increased the N availability relative to raw cattle-slurry (15% of organic N applied mineralised against negative mineralisation in raw slurry). However, similar NH3 emissions and GWP were observed in acidified LF and non-acidified LF treatments. On the other hand, soil application of acidified cattle-slurry rather than non-acidified LF should be preferred attending the lower costs associated to acidification compared to solid-liquid separation. It can then be concluded that cattle-slurry acidification is a solution to minimise NH3 emissions from amended soil and an efficient strategy to decrease the GWP associated with slurry application to soil. Furthermore, the more intense N mineralisation observed with acidified slurry should lead to a higher amount of plant available N and consequently to higher crop yields. Copyright © 2015 Elsevier Ltd. All rights reserved.

Understanding the creation of & reducing surface microroughness during polishing & post-processing of glass optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suratwala, Tayyab

2016-09-22

In the follow study, we have developed a detailed understanding of the chemical and mechanical microscopic interactions that occur during polishing affecting the resulting surface microroughness of the workpiece. Through targeted experiments and modeling, the quantitative relationships of many important polishing parameters & characteristics affecting surface microroughness have been determined. These behaviors and phenomena have been described by a number of models including: (a) the Ensemble Hertzian Multi Gap (EHMG) model used to predict the removal rate and roughness at atomic force microscope (AFM) scale lengths as a function of various polishing parameters, (b) the Island Distribution Gap (IDG) modelmore » used to predict the roughness at larger scale lengths, (c) the Deraguin-Verwey-Landau-Overbeek (DLVO) 3-body electrostatic colloidal model used to predict the interaction of slurry particles at the interface and roughness behavior as a function of pH, and (d) a diffusion/chemical reaction rate model of the incorporation of impurities species into the polishing surface layer (called the Bielby layer). Based on this improved understanding, novel strategies to polish the workpiece have been developed simultaneously leading to both ultrasmooth surfaces and high material removal rates. Some of these strategies include: (a) use of narrow PSD slurries, (b) a novel diamond conditioning recipe of the lap to increase the active contact area between the workpiece and lap without destroying its surface figure, (c) proper control of pH for a given glass type to allow for a uniform distribution of slurry particles at the interface, and (d) increase in applied load just up to the transition between molecular to plastic removal regime for a single slurry particle. These techniques have been incorporated into a previously developed finishing process called Convergent Polishing leading to not just economical finishing process with improved surface figure control, but also simultaneously leading to low roughness surface with high removal rates.« less

Ice Slurry Ingestion and Physiological Strain During Exercise in Non-Compensable Heat Stress.

PubMed

Ng, Jason; Wingo, Jonathan E; Bishop, Phillip A; Casey, Jason C; Aldrich, Elizabeth K

2018-05-01

Precooling with ice slurry ingestion attenuates the increase in rectal temperature (Tre) during subsequent running and cycling. It remains unclear how this cooling method affects physiological strain during work while wearing protective garments. This study investigated the effect of ice slurry ingestion on physiological strain during work in hot conditions while wearing firefighter protective clothing. In three counterbalanced trials, eight men (mean ± SD; age = 21 ± 2 yr, height = 179.5 ± 3.5 cm, mass = 79.1 ± 4.1 kg, body fat = 11.4 ± 3.7%) wore firefighter protective clothing and walked (4 km · h-1, 12% incline, ∼7 METs) for 30 min in hot conditions (35°C, 40% RH). Every 2.5 min, subjects ingested 1.25 g · kg-1 (relative total: 15 g · kg-1, absolute total: 1186.7 ± 61.3 g) of a tepid (22.4 ± 1.7°C), cold (7.1 ± 1.5°C), or ice slurry (-1.3 ± 0.2°C) beverage. Heart rates (HR) were lower with ice slurry ingestion compared to both fluid trials starting 5 min into exercise (tepid = 158 ± 14, cold = 157 ± 11, ice slurry = 146 ± 13 bpm) and persisting for the remainder of the bout (min 30: tepid = 196 ± 10, cold = 192 ± 10, ice slurry = 181 ± 13 bpm). Tre was lower with ice slurry ingestion compared to cold and tepid trials (min 5: tepid = 37.17 ± 0.38, cold = 37.17 ± 0.39, ice slurry = 37.05 ± 0.43°C; min 30: tepid = 38.15 ± 0.29, cold = 38.31 ± 0.36, ice slurry = 37.95 ± 0.32°C). The physiological strain index (PSI) was lower with ice slurry ingestion compared to fluid trials starting at min 5 (tepid = 3.8 ± 0.7, cold = 3.8 ± 0.6, ice slurry = 3.0 ± 0.5) and remained lower throughout exercise (min 30: tepid = 8.2 ± 0.6, cold = 8.3 ± 0.9, ice slurry = 6.9 ± 1.2). A large quantity of ice slurry ingested under non-compensable heat stress conditions mitigated physiological strain during exercise by blunting the rise in heart rate and rectal temperature.Ng J, Wingo JE, Bishop PA, Casey JC, Aldrich EK. Ice slurry ingestion and physiological strain during exercise in non-compensable heat stress. Aerosp Med Hum Perform. 2018; 89(5):434-441.

A 'Propagating' Active Across-Arc Normal Fault Shows Rupture Process of the Basement: the Case of the Southwestern Ryukyu Arc

NASA Astrophysics Data System (ADS)

Matsumoto, T.; Shinjo, R.; Nakamura, M.; Kubo, A.; Doi, A.; Tamanaha, S.

2011-12-01

Ryukyu Arc is located on the southwestern extension of Japanese Island-arc towards the east of Taiwan Island along the margin of the Asian continent off China. The island-arc forms an arcuate trench-arc-backarc system. A NW-ward subduction of the Philippine Sea Plate (PSP)at a rate of 6-8 cm/y relative to the Eurasian Plate (EP) causes frequent earthquakes. The PSP is subducting almost normally in the north-central area and more obliquely around the southwestern area. Behind the arc-trench system, the Okinawa Trough (OT) was formed by back-arc rifting, where active hydrothermal vent systems have been discovered. Several across-arc submarine faults are located in the central and southern Ryukyu Arc. The East Ishigaki Fault (EIF) is one of the across-arc normal faults located in the southwestern Ryukyu Arc, ranging by 44km and extending from SE to NW. This fault was surveyed by SEABAT8160 multibeam echo sounder and by ROV Hyper-Dolphin in 2005 and 2008. The result shows that the main fault consists of five fault segments. A branched segment from the main fault was also observed. The southernmost segment is most mature (oldest but still active) and the northernmost one is most nascent. This suggests the north-westward propagation of the fault rupture corresponding to the rifting of the southwestern OT and the southward retreat of the arc-trench system. Considering that the fault is segmented and in some part branched, propagation might take place episodically rather than continuously from SE to NW. The ROV survey also revealed the rupture process of the limestone basement along this fault from the nascent stage to the mature stage. Most of the rock samples collected from the basement outcrop were limestone blocks (or calcareous sedimentary rocks). Limestone basement was observed to the west on the hanging wall far away from the main fault scarp. Then fine-grained sand with ripple marks was observed towards the main scarp. Limestone basement was observed on the main scarp and on the footwall. These suggest that basically the both sides are composed of the same material, that the whole study area is characterised by Ryukyu limestone exposure and that the basement was split by the across-arc normal fault. Coarse-grained sand and gravels/rubbles were observed towards and on the trough of the fault. On the main scarp an outcrop of limestone basement was exposed and in some part it was broken into rubbles. These facts suggest that crash of the basement due to rupturing is taking place repeatedly on the scarp and the trough. The observed fine-grained sand on the hanging wall might be the final product by the process of the crash of the limestone basement.

Simulation of fluidized bed coal combustors

NASA Technical Reports Server (NTRS)

Rajan, R.

1979-01-01

The many deficiencies of previous work on simulation of fluidized bed combustion (FBC) processes are presented. An attempt is made to reduce these deficiencies, and to formulate a comprehensive FBC model taking into account the following elements: (1) devolatilization of coal and the subsequent combustion of volatiles and residual char; (2) sulfur dioxide capture by limestone; (3) NOx release and reduction of NOx by char; (4) attrition and elutriation of char and limestone; (5) bubble hydrodynamics; (6) solids mixing; (7) heat transfer between gas and solid, and solid and heat exchange surfaces; and (8) freeboard reactions.

Method for applying a high-temperature bond coat on a metal substrate, and related compositions and articles

DOEpatents

Hasz, Wayne Charles; Sangeeta, D

2006-04-18

A method for applying a bond coat on a metal-based substrate is described. A slurry which contains braze material and a volatile component is deposited on the substrate. The slurry can also include bond coat material. Alternatively, the bond coat material can be applied afterward, in solid form or in the form of a second slurry. The slurry and bond coat are then dried and fused to the substrate. A repair technique using this slurry is also described, along with related compositions and articles.

Method for applying a high-temperature bond coat on a metal substrate, and related compositions and articles

DOEpatents

Hasz, Wayne Charles; Sangeeta, D

2002-01-01

A method for applying a bond coat on a metal-based substrate is described. A slurry which contains braze material and a volatile component is deposited on the substrate. The slurry can also include bond coat material. Alternatively, the bond coat material can be applied afterward, in solid form or in the form of a second slurry. The slurry and bond coat are then dried and fused to the substrate. A repair technique using this slurry is also described, along with related compositions and articles.

Continuous-flow stirred-tank reactor 20-L demonstration test: Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, D.D.; Collins, J.L.

One of the proposed methods of removing the cesium, strontium, and transuranics from the radioactive waste storage tanks at Savannah River is the small-tank tetraphenylborate (TPB) precipitation process. A two-reactor-in-series (15-L working volume each) continuous-flow stirred-tank reactor (CSTR) system was designed, constructed, and installed in a hot cell to test the Savannah River process. The system also includes two cross-flow filtration systems to concentrate and wash the slurry produced in the process, which contains the bulk of radioactivity from the supernatant processed through the system. Installation, operational readiness reviews, and system preparation and testing were completed. The first test usingmore » the filtration systems, two CSTRs, and the slurry concentration system was conducted over a 61-h period with design removal of Cs, Sr, and U achieved. With the successful completion of Test 1a, the following tests, 1b and 1c, were not required.« less

PREPARATION OF ALKYL PYROPHOSPHATE EXTRACTANTS

DOEpatents

Levine, C.A.; Skiens, W.E.; Moore, G.R.

1960-08-01

A process for providing superior solvent extractants for metal recovery processes is given wherein the extractant comprises an alkyl pyrophosphoric acid ester dissolved in an organic solvent diluent. Finely divided solid P/sub 2/O/ sub 5/ is slurried in an organic solvent-diluent selected from organic solvents such as kerosene, benzene, chlorobenzene, toluene, etc. An alcohol selected from the higher alcohols having 4 to 17 carbon atoms. e.g.. hexanol-1. heptanol-3, octanol-1. 2.6-dimethyl-heptanol-4, and decanol-1, is rapidly added to the P/sub 2/O/sub 5/ slurry in the amount of about 2 moles of alcohol to 1 mole of P/sub 2/ O/sub 5/. The temperature is maintained below about 110 deg C during the course of the P/sub 2/O/sub 5/-alcohol reaction. An alkyl pyrophosphate extractant compound is formed as a consequence of the reaction process. The alkyl pyrophosphate solvent-diluent extractant phase is useful in solvent extraction metal recovery processes.

Optimization of Limestone Feed Size of a Pressurized Fluidized Bed Combustor

NASA Astrophysics Data System (ADS)

Shimizu, Tadaaki; Saastamolnen, Jaakko

Limestone attrition is a major cause of loss of limestone during pressurized fluidized bed combustion. In the authors' previous works, the analysis of published results of solid attrition and desulfurization was conducted to determine the attrition rate expression. The specific attrition rate (rate of decrease in diameter) was estimated to be second order with respect to particle diameter in the previous work. This rate expression implies that reduction of feed size of limestone is effective for suppression of loss of limestone by attrition. However, too much grinding of raw limestone will increase the content of fine particles that are readily elutriated by gas stream and do not contribute to the sulfur capture. In this work, modeling works are conducted for particle attrition and desulfurization in order to predict the effect of feed size of limestone on total consumption of limestone and desulfurization is discussed. Optimum particle size to suppress limestone consumption was approximately 0.7 mm (as D p50 ). However, the control of solid drain rate from the bottom was found to have more influence on total limestone consumption rate. Emissions of SO2 from low sulfur coal (S=0.33%) could be sufficiently low irrespective of limestone feed size but SO2 emissions from coals with higher sulfur content than 0.5% were anticipated to increase drastically. Such drastic change in SO2 emissions with the change in sulfur content is attributable to non-linear nature of reaction rate for attrition-enhanced desulfurization by limestone.

An innovative carbonate coprecipitation process for the removal of zinc and manganese from mining impacted waters

USGS Publications Warehouse

Sibrell, P.L.; Chambers, M.A.; Deaguero, A.L.; Wildeman, T.R.; Reisman, D.J.

2007-01-01

Although mine drainage is usually thought of as acidic, there are many cases where the water is of neutral pH, but still contains metal species that can be harmful to human or aquatic animal health, such as manganese (Mn) and zinc (Zn). Typical treatment of mine drainage waters involves pH adjustment, but this often results in excessive sludge formation and removal of nontoxic species such as magnesium and calcium. Theoretical consideration of the stability of metal carbonate species suggests that the target metals could be removed from solution by coprecipitation with calcium carbonate. The U.S. Geological Survey has developed a limestone-based process for remediation of acid mine drainage that increases calcium carbonate saturation. This treatment could then be coupled with carbonate coprecipitation as an innovative method for removal of toxic metals from circumneutral mine drainage waters. The new process was termed the carbonate coprecipitation (CCP) process. The CCP process was tested at the laboratory scale using a synthetic mine water containing 50 mg/L each of Mn and Zn. Best results showed over 95% removal of both Mn and Zn in less than 2 h of contact in a limestone channel. The process was then tested on a sample of water from the Palmerton zinc superfund site, near Palmerton, Pennsylvania, containing over 300 mg/L Zn and 60 mg/L Mn. Treatment of this water resulted in removal of over 95% of the Zn and 40% of the Mn in the limestone channel configuration. Because of the potential economic advantages of the CCP process, further research is recommended for refinement of the process for the Palmerton water and for application to other mining impacted waters as well. ?? Mary Ann Liebert, Inc.

Estimating Preferential Flow in Karstic Aquifers Using Statistical Mixed Models

PubMed Central

Anaya, Angel A.; Padilla, Ingrid; Macchiavelli, Raul; Vesper, Dorothy J.; Meeker, John D.; Alshawabkeh, Akram N.

2013-01-01

Karst aquifers are highly productive groundwater systems often associated with conduit flow. These systems can be highly vulnerable to contamination, resulting in a high potential for contaminant exposure to humans and ecosystems. This work develops statistical models to spatially characterize flow and transport patterns in karstified limestone and determines the effect of aquifer flow rates on these patterns. A laboratory-scale Geo-HydroBed model is used to simulate flow and transport processes in a karstic limestone unit. The model consists of stainless-steel tanks containing a karstified limestone block collected from a karst aquifer formation in northern Puerto Rico. Experimental work involves making a series of flow and tracer injections, while monitoring hydraulic and tracer response spatially and temporally. Statistical mixed models are applied to hydraulic data to determine likely pathways of preferential flow in the limestone units. The models indicate a highly heterogeneous system with dominant, flow-dependent preferential flow regions. Results indicate that regions of preferential flow tend to expand at higher groundwater flow rates, suggesting a greater volume of the system being flushed by flowing water at higher rates. Spatial and temporal distribution of tracer concentrations indicates the presence of conduit-like and diffuse flow transport in the system, supporting the notion of both combined transport mechanisms in the limestone unit. The temporal response of tracer concentrations at different locations in the model coincide with, and confirms the preferential flow distribution generated with the statistical mixed models used in the study. PMID:23802921

Estimating preferential flow in karstic aquifers using statistical mixed models.

PubMed

Anaya, Angel A; Padilla, Ingrid; Macchiavelli, Raul; Vesper, Dorothy J; Meeker, John D; Alshawabkeh, Akram N

2014-01-01

Karst aquifers are highly productive groundwater systems often associated with conduit flow. These systems can be highly vulnerable to contamination, resulting in a high potential for contaminant exposure to humans and ecosystems. This work develops statistical models to spatially characterize flow and transport patterns in karstified limestone and determines the effect of aquifer flow rates on these patterns. A laboratory-scale Geo-HydroBed model is used to simulate flow and transport processes in a karstic limestone unit. The model consists of stainless steel tanks containing a karstified limestone block collected from a karst aquifer formation in northern Puerto Rico. Experimental work involves making a series of flow and tracer injections, while monitoring hydraulic and tracer response spatially and temporally. Statistical mixed models (SMMs) are applied to hydraulic data to determine likely pathways of preferential flow in the limestone units. The models indicate a highly heterogeneous system with dominant, flow-dependent preferential flow regions. Results indicate that regions of preferential flow tend to expand at higher groundwater flow rates, suggesting a greater volume of the system being flushed by flowing water at higher rates. Spatial and temporal distribution of tracer concentrations indicates the presence of conduit-like and diffuse flow transport in the system, supporting the notion of both combined transport mechanisms in the limestone unit. The temporal response of tracer concentrations at different locations in the model coincide with, and confirms the preferential flow distribution generated with the SMMs used in the study. © 2013, National Ground Water Association.

Measurement of rheology of distiller's grain slurries using a helical impeller viscometer.

PubMed

Houchin, Tiffany L; Hanley, Thomas R

2004-01-01

Current research is focused on developing a process to convert the cellulose and hemicellulose in distiller's grains into fermentable sugars, increasing both ethanol yield and the amount of protein in the remaining solid product. The rheologic properties of distiller's grain slurries were determined for concentrations of 21, 23, and 25%. Distiller's grain slurries are non-Newtonian, heterogeneous fluids subject to particle settling. Traditional methods of viscosity measurement, such as cone-and-plate and concentric cylinder viscometers, are not adequate for these fluids. A helical impeller viscometer was employed to measure impeller torque over a range of rotational speeds. Newtonian and non-Newtonian calibration fluids were utilized to obtain constants that relate shear stresses and shear rates to the experimental data. The Newtonian impeller constant, c, was 151; the non-Newtonian shear rate constant, k, was 10.30. Regression analysis of experimental data was utilized for comparison to power law, Herschel-Bulkley, and Casson viscosity models with regression coefficients exceeding 0.99 in all cases.

Salinity Responses of Benthic Microbial Communities in a Solar Saltern (Eilat, Israel)

PubMed Central

Sørensen, Ketil Bernt; Canfield, Donald E.; Oren, Aharon

2004-01-01

The salinity responses of cyanobacteria, anoxygenic phototrophs, sulfate reducers, and methanogens from the laminated endoevaporitic community in the solar salterns of Eilat, Israel, were studied in situ with oxygen microelectrodes and in the laboratory in slurries. The optimum salinity for the sulfate reduction rate in sediment slurries was between 100 and 120‰, and sulfate reduction was strongly inhibited at an in situ salinity of 215‰. Nevertheless, sulfate reduction was an important respiratory process in the crust, and reoxidation of formed sulfide accounted for a major part of the oxygen budget. Methanogens were well adapted to the in situ salinity but contributed little to the anaerobic mineralization in the crust. In slurries with a salinity of 180‰ or less, methanogens were inhibited by increased activity of sulfate-reducing bacteria. Unicellular and filamentous cyanobacteria metabolized at near-optimum rates at the in situ salinity, whereas the optimum salinity for anoxygenic phototrophs was between 100 and 120‰. PMID:15006785

Slurry Erosion Studies on Surface Modified 13Cr-4Ni Steels: Effect of Angle of Impingement and Particle Size

NASA Astrophysics Data System (ADS)

Manisekaran, T.; Kamaraj, M.; Sharrif, S. M.; Joshi, S. V.

2007-10-01

Hydroturbine steels, such as 13Cr-4Ni martensitic steels, are generally subjected to heavy-erosive wear and loss of efficiency due to solid particulate entrainment in the water. Surface-modified steels have proven to give better performance in terms of erosive wear resistance. In the present study, an attempt is made to investigate the effect of angle of impingement and particle size on slurry-jet erosion behavior of pulsed plasma nitrided and laser hardened 13Cr-4Ni steels. Laser hardening process has shown good performance at all angles of impingement due to martensitic transformation of retained austenite. Plastic deformation mode of material removal was also an evident feature of all laser-hardened surface damage locations. However, pulsed-plasma nitrided steels have exhibited chip formation and micro-cutting mode of erosive wear. Erosion with 150-300 μm size was twice compared to 150 μm size slurry particulates.

Hybrid micro-particles as a magnetically-guidable decontaminant for cesium-eluted ash slurry

NASA Astrophysics Data System (ADS)

Namiki, Yoshihisa; Ueyama, Toshihiko; Yoshida, Takayuki; Watanabe, Ryoei; Koido, Shigeo; Namiki, Tamami

2014-09-01

Decontamination of the radioactive cesium that is widely dispersed owing to a nuclear power station accident and concentrated in fly ash requires an effective elimination system. Radioactive fly ash contains large amounts of water-soluble cesium that can cause severe secondary contamination and represents a serious health risk, yet its complete removal is complicated and difficult. Here it is shown that a new fine-powder formulation can be magnetically guided to eliminate cesium after being mixed with the ash slurry. This formulation, termed MagCE, consists of a ferromagnetic porous structure and alkaline- and salt-resistant nickel ferrocyanide. It has potent cesium-adsorption- and magnetic-separation-properties. Because of its resistance against physical and chemical attack such as with ash particles, as well as with the high pH and salt concentration of the ash slurry, MagCE simplifies the decontamination process without the need of the continued presence of the hazardous water-soluble cesium in the treated ash.

Separation of catalyst from Fischer-Tropsch slurry

DOEpatents

White, C.M.; Quiring, M.S.; Jensen, K.L.; Hickey, R.F.; Gillham, L.D.

1998-10-27

In a catalytic process for converting synthesis gas including hydrogen and carbon monoxide to hydrocarbons and oxygenates by a slurry Fischer-Tropsch synthesis, the wax product along with dispersed catalyst is removed from the slurry and purified by removing substantially all of the catalyst prior to upgrading the wax and returning a portion to the Fischer-Tropsch reaction. Separation of the catalyst particles from the wax product is accomplished by dense gas and/or liquid extraction in which the organic compounds in the wax are dissolved and carried away from the insoluble inorganic catalyst particles that are primarily inorganic in nature. The purified catalyst-free wax product can be subsequently upgraded by various methods such as hydrogenation, isomerization, hydrocracking, conversion to gasoline and other products over ZSM-5 aluminosilicate zeolite, etc. The catalyst particles are returned to the Fischer-Tropsch Reactor by mixing them with a wax fraction of appropriate molecular weight, boiling point and viscosity to avoid reactor gelation. 2 figs.

An improved polymeric sponge replication method for biomedical porous titanium scaffolds.

PubMed

Wang, Chunli; Chen, Hongjie; Zhu, Xiangdong; Xiao, Zhanwen; Zhang, Kai; Zhang, Xingdong

2017-01-01

Biomedical porous titanium (Ti) scaffolds were fabricated by an improved polymeric sponge replication method. The unique formulations and distinct processing techniques, i.e. a mixture of water and ethanol as solvent, multiple coatings with different viscosities of the Ti slurries and centrifugation for removing the extra slurries were used in the present study. The optimized porous Ti scaffolds had uniform porous structure and completely interconnected macropores (~365.1μm). In addition, two different sizes of micropores (~45.4 and ~6.2μm) were also formed in the skeleton of the scaffold. The addition of ethanol to the Ti slurry increased the compressive strength of the scaffold by improving the compactness of the skeleton. A compressive strength of 83.6±4.0MPa was achieved for a porous Ti scaffold with a porosity of 66.4±1.8%. Our cellular study also revealed that the scaffolds could support the growth and proliferation of mesenchymal stem cells (MSCs). Copyright © 2016 Elsevier B.V. All rights reserved.

Hybrid micro-particles as a magnetically-guidable decontaminant for cesium-eluted ash slurry

PubMed Central

Namiki, Yoshihisa; Ueyama, Toshihiko; Yoshida, Takayuki; Watanabe, Ryoei; Koido, Shigeo; Namiki, Tamami

2014-01-01

Decontamination of the radioactive cesium that is widely dispersed owing to a nuclear power station accident and concentrated in fly ash requires an effective elimination system. Radioactive fly ash contains large amounts of water-soluble cesium that can cause severe secondary contamination and represents a serious health risk, yet its complete removal is complicated and difficult. Here it is shown that a new fine-powder formulation can be magnetically guided to eliminate cesium after being mixed with the ash slurry. This formulation, termed MagCE, consists of a ferromagnetic porous structure and alkaline- and salt-resistant nickel ferrocyanide. It has potent cesium-adsorption- and magnetic-separation-properties. Because of its resistance against physical and chemical attack such as with ash particles, as well as with the high pH and salt concentration of the ash slurry, MagCE simplifies the decontamination process without the need of the continued presence of the hazardous water-soluble cesium in the treated ash. PMID:25192495

The toxicity of selected gasoline components to glucose methanogenesis by aquifer microorganisms

USGS Publications Warehouse

Mormile, Melanie R.; Suflita, Joseph M.

1996-01-01

Six model hydrocarbons, representing various classes of chemicals found in gasoline, and methyl ethyl ketone, were assayed for their inhibitory effect on glucose methanogenesis in slurries prepared from aquifer sediments and ground water. Biogas (CH4and CO2) production was monitored with an automated pressure transducer system. Benzene, 1-methyl naphthalene, and methyltert-butyl ether (MTBE) were found to have no inhibitory influence on biogas production rates at concentrations up to 71·7 mg/L. Similarly, octane, cyclohexane, indan, and methyl ethyl ketone (MEK) were found to have only marginal negative effects on the rate of biogas production in aquifer slurries, at concentrations ranging from 51·7 to 72·1 mg/L. Thus, gasoline components had low apparent toxicities to microorganisms responsible for glucose methanogenesis in aquifier slurries. As the concentrations of the assayed hydrocarbons are about 100 times those typically reported after an aquifer has been contaminated with gasoline, it is unlikely that individual hydrocarbons will substantially impact anaerobic metabolic processes.

Hybrid micro-particles as a magnetically-guidable decontaminant for cesium-eluted ash slurry.

PubMed

Namiki, Yoshihisa; Ueyama, Toshihiko; Yoshida, Takayuki; Watanabe, Ryoei; Koido, Shigeo; Namiki, Tamami

2014-09-05

Decontamination of the radioactive cesium that is widely dispersed owing to a nuclear power station accident and concentrated in fly ash requires an effective elimination system. Radioactive fly ash contains large amounts of water-soluble cesium that can cause severe secondary contamination and represents a serious health risk, yet its complete removal is complicated and difficult. Here it is shown that a new fine-powder formulation can be magnetically guided to eliminate cesium after being mixed with the ash slurry. This formulation, termed MagCE, consists of a ferromagnetic porous structure and alkaline- and salt-resistant nickel ferrocyanide. It has potent cesium-adsorption- and magnetic-separation-properties. Because of its resistance against physical and chemical attack such as with ash particles, as well as with the high pH and salt concentration of the ash slurry, MagCE simplifies the decontamination process without the need of the continued presence of the hazardous water-soluble cesium in the treated ash.

Methane yields and methanogenic community changes during co-fermentation of cattle slurry with empty fruit bunches of oil palm.

PubMed

Walter, Andreas; Franke-Whittle, Ingrid H; Wagner, Andreas O; Insam, Heribert

2015-01-01

The biomethane potential and structural changes of the methanogenic community in a solid-state anaerobic digestion process co-digesting cattle slurry and empty fruit bunches were investigated under mesophilic (37°C) and thermophilic (55°C) conditions. Phylogenetic microarrays revealed the presence of two hydrogenotrophic genera (Methanoculleus and Methanobrevibacter) and one acetoclastic genus (Methanosarcina). Methanosarcina numbers were found to increase in both mesophilic and thermophilic treatments of empty fruit bunches. Methanobrevibacter, which dominated in the cattle slurry, remained constant during anaerobic digestion (AD) at 37°C and decreased in numbers during digestion at 55°C. Numbers of Methanoculleus remained constant at 37°C and increased during the thermophilic digestion. Physicochemical data revealed non-critical concentrations for important monitoring parameters such as total ammonia nitrogen, free ammonia nitrogen and volatile fatty acids in all treatments after AD. The biomethane potential of empty fruit bunches was higher under thermophilic conditions than under mesophilic conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microbial desulfurization of coal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stevens, S.E. Jr.; Burgess, W.D.

This patent describes a process for the microbial desulfurization of solid carbonaceous solids. The process comprising subjecting an aqueous slurry of carbonaceous solids to the desulfurizing action of microorganisms selected from the group consisting of Hansenula sydowiorum, Hansenula ciferii, Hansenula lynferdii, Cryptococcus albidus and mixtures thereof. Also described is the same process wherein the carbonaceous solids is coal.

Evolution of process control parameters during extended co-composting of green waste and solid fraction of cattle slurry to obtain growing media.

PubMed

Cáceres, Rafaela; Coromina, Narcís; Malińska, Krystyna; Marfà, Oriol

2015-03-01

This study aimed to monitor process parameters when two by-products (green waste - GW, and the solid fraction of cattle slurry - SFCS) were composted to obtain growing media. Using compost in growing medium mixtures involves prolonged composting processes that can last at least half a year. It is therefore crucial to study the parameters that affect compost stability as measured in the field in order to shorten the composting process at composting facilities. Two mixtures were prepared: GW25 (25% GW and 75% SFCS, v/v) and GW75 (75% GW and 25% SFCS, v/v). The different raw mixtures resulted in the production of two different growing media, and the evolution of process management parameters was different. A new parameter has been proposed to deal with attaining the thermophilic temperature range and maintaining it during composting, not only it would be useful to optimize composting processes, but also to assess the hygienization degree. Copyright © 2014 Elsevier Ltd. All rights reserved.

Limestone and Zeolite as Alternative Media in Horizontal Subsurface Flow Constructed Wetlands: Laboratory-Scale Studies

NASA Astrophysics Data System (ADS)

Lizama, K.; Jaque, I.; Ayala, J.

2016-12-01

Arsenic is well known for its chronic toxicity. Millions of people around the world are currently at risk, drinking water with As concentrations above 10 ppb, the WHO drinking water guideline. Although different treatment options exist, they are often limited by elevated costs and maintenance requirements. Constructed wetlands are a natural water treatment system, capable to remove metals and metalloids -including As- via different physical, chemical and biological processes. The use of alternative supporting media to enhance As removal in subsurface flow wetlands has been recommended, but not sufficiently studied. Limestone and zeolite have been identified as effective supporting media in subsurface flow wetlands aiming As removal. However, there are still key aspects to be addressed, such as the implications of using these media, the speciation in the solid phase, the role of vegetation, etc. This study investigated the performance of limestone and zeolite in three types of experiments: batch, column and as main supporting media in a bench scale horizontal subsurface flow wetland system. Synthetic water resembling a contaminated river in Chile (As concentration=3 mg/L, Fe concentration= 100 mg/L, pH=2) was used in all experiments. In the batch experiments, the As concentration, the mass of media and the contact time were varied. The column system consisted of three limestone columns and three zeolite columns, operated under a hydraulic loading of 20 mm/d. The wetland system consisted of twelve PVC cells: six filled with zeolite and six with limestone. Phragmites australis were planted in three cells of each media type, as control cells. From the batch experiments, maximum As sorption capacities as indicated by Langmuir model were 1.3 mg/g for limestone and 0.17 mg/g for zeolite, at 18 h contact time and 6.3 g/L medium concentration. EDS and XPS analyses revealed that As and Fe were retained in zeolite at the end of the batch experiments. Zeolite and limestone columns presented As removal >99.5% on average. In the wetland system, As removal percentages were also similar between media types, regardless of the presence of vegetation: For limestone, removal percentages were 99.7% and 99.6%, for vegetated and non-vegetated cells respectively; whereas for zeolite, removal percentages were 99.8% and 99.7% respectively.

Evaluation of solar photocatalysis using TiO2 slurry in the inactivation of Cryptosporidium parvum oocysts in water.

PubMed

Abeledo-Lameiro, María Jesús; Ares-Mazás, Elvira; Gómez-Couso, Hipólito

2016-10-01

Cryptosporidium is a genus of enteric protozoan parasites of medical and veterinary importance, whose oocysts have been reported to occur in different types of water worldwide, offering a great resistant to the water treatment processes. Heterogeneous solar photocatalysis using titanium dioxide (TiO2) slurry was evaluated on inactivation of Cryptosporidium parvum oocysts in water. Suspensions of TiO2 (0, 63, 100 and 200mg/L) in distilled water (DW) or simulated municipal wastewater treatment plant (MWTP) effluent spiked with C. parvum oocysts were exposed to simulated solar radiation. The use of TiO2 slurry at concentrations of 100 and 200mg/L in DW yielded a high level of oocyst inactivation after 5h of exposure (4.16±2.35% and 15.03±4.54%, respectively, vs 99.33±0.58%, initial value), representing a good improvement relative to the results obtained in the samples exposed without TiO2 (51.06±9.35%). However, in the assays carried out using simulated MWTP effluent, addition of the photocatalyst did not offer better results. Examination of the samples under bright field and epifluorescence microscopy revealed the existence of aggregates comprising TiO2 particles and parasitic forms, which size increased as the concentration of catalyst and the exposure time increased, while the intensity of fluorescence of the oocyst walls decreased. After photocatalytic disinfection process, the recovery of TiO2 slurry by sedimentation provided a substantial reduction in the parasitic load in treated water samples (57.81±1.10% and 82.10±2.64% for 200mg/L of TiO2 in DW and in simulated MWTP effluent, respectively). Although further studies are need to optimize TiO2 photocatalytic disinfection against Cryptosporidium, the results obtained in the present study show the effectiveness of solar photocatalysis using TiO2 slurry in the inactivation of C. parvum oocysts in distilled water. Copyright © 2016 Elsevier B.V. All rights reserved.

Biological treatment of soils contaminated with hydrophobic organics using slurry- and solid-phase techniques

NASA Astrophysics Data System (ADS)

Cassidy, Daniel H.; Irvine, Robert L.

1995-10-01

Both slurry-phase and solid-phase bioremediation are effective ex situ soil decontamination methods. Slurrying is energy intensive relative to solid-phase treatment, but provides homogenization and uniform nutrient distribution. Limited contaminant bioavailability at concentrations above the required cleanup level reduces biodegradation rates and renders solid phase bioremediation more cost effective than complete treatment in a bio-slurry reactor. Slurrying followed by solid-phase bioremediation combines the advantages and minimizes the weaknesses of each treatment method when used alone. A biological treatment system consisting of slurrying followed by aeration in solid phase bioreactors was developed and tested in the laboratory using a silty clay loam contaminated with diesel fuel. The first set of experiments was designed to determine the impact of the water content and mixing time during slurrying on the rate an extent of contaminant removal in continuously aerated solid phase bioreactors. The second set of experiments compared the volatile and total diesel fuel removal in solid phase bioreactors using periodic and continuous aeration strategies. Results showed that slurrying for 1.5 hours at a water content less than saturation markedly increased the rate and extent of contaminant biodegradation in the solid phase bioreactors compared with soil having no slurry pretreatment. Slurrying the soil at or above its saturation moisture content resulted in lengthy dewatering times which prohibited aeration, thereby delaying the onset of biological treatment in the solid phase bioreactors. Results also showed that properly operated periodic aeration can provide less volatile contaminant removal and a grater fraction of biological contaminant removal than continuous aeration.

Surface texture and composition of titanium brushed with toothpaste slurries of different pHs.

PubMed

Hossain, Awlad; Okawa, Seigo; Miyakawa, Osamu

2007-02-01

This in vitro study characterized the surface texture and composition of titanium brushed with toothpaste slurries of different pHs, and thereby elucidated mechanochemical interactions between the metal and abrasive material in dentifrice. Two fluoride-free toothpastes, which contained crystalline CaHPO(4).2H(2)O and amorphous SiO(2) particles as abrasive, were mixed with acidic buffers to provide slurries of pH 6.8 and 4.8. Specimens were cast from CP Ti, mirror-polished, and then toothbrushed at 120strokes/min for 350,400 strokes under a load of 2.45N. Specimen surfaces were characterized by means of SPM and EPMA. The obtained data were compared with the already reported results of water-diluted alkaline slurries. SPM data of each paste were analyzed using one-way ANOVA, followed by post hoc Tukey test. Irrespective of toothpaste, neutral slurries, as with alkaline slurries, yielded a chemically altered surface with rough texture, whereas acidic slurries formed a chemically clean surface with relatively smooth texture. Mechanochemical polishing effect might be mainly responsible for the cleanness and smoothness. Acidic slurry-induced smooth surface may minimize plaque formation. However, the augmentation of released titanium ions may be adverse to the human body. For evaluation of toothpaste abrasion effects on titanium, paste slurry pH should be taken into account.

Apparatus and method for transferring slurries

DOEpatents

Horton, J.R.

1982-08-13

Slurry is transferred to a high pressure region by pushing the slurry from the bottom of a transfer vessel with a pressurizing liquid admitted into the top of the vessel. While the pressurizing liquid is being introduced into the transfer vessel, pressurizing liquid which has mixed with slurry is drawn off from the transfer vessel at a point between its upper and lower ends.

Apparatus and method for transferring slurries

DOEpatents

Horton, Joel R.

1984-01-01

Slurry is transferred to a high pressure region by pushing the slurry from the bottom of a transfer vessel with a pressurizing liquid admitted into the top of the vessel. While the pressurizing liquid is being introduced into the transfer vessel, pressurizing liquid which has mixed with slurry is drawn off from the transfer vessel at a point between its upper and lower ends.

SEPARATING LIQUID MODERATOR FROM A SLURRY TYPE REACTOR

DOEpatents

Vernon, H.C.

1961-07-01

A system for evaporating moderator such as D/sub 2/O from an irradiated slurry or sloution characterized by two successive evaproators is described. In the first of these the most troublesome radioactivity dissipates before the slurry becomes too thick to be pumped out; in the second the slurry, now easier to handle, can be safely reduced to a sludge.

Supersonic coal water slurry fuel atomizer

DOEpatents

Becker, Frederick E.; Smolensky, Leo A.; Balsavich, John

1991-01-01

A supersonic coal water slurry atomizer utilizing supersonic gas velocities to atomize coal water slurry is provided wherein atomization occurs externally of the atomizer. The atomizer has a central tube defining a coal water slurry passageway surrounded by an annular sleeve defining an annular passageway for gas. A converging/diverging section is provided for accelerating gas in the annular passageway to supersonic velocities.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Higa, Kenneth; Zhao, Hui; Parkinson, Dilworth Y.

The internal structure of a porous electrode strongly influences battery performance. Understanding the dynamics of electrode slurry drying could aid in engineering electrodes with desired properties. For instance, one might monitor the dynamic, spatially-varying thickness near the edge of a slurry coating, as it should lead to non-uniform thickness of the dried film. This work examines the dynamic behavior of drying slurry drops consisting of SiO x and carbon black particles in a solution of carboxymethylcellulose and deionized water, as an experimental model of drying behavior near the edge of a slurry coating. An X-ray radiography-based procedure is developed tomore » calculate the evolving spatial distribution of active material particles from images of the drying slurry drops. To the authors’ knowledge, this study is the first to use radiography to investigate battery slurry drying, as well as the first to determine particle distributions from radiography images of drying suspensions. The dynamic results are consistent with tomography reconstructions of the static, fully-dried films. It is found that active material particles can rapidly become non-uniformly distributed within the drops. Heating can promote distribution uniformity, but seemingly must be applied very soon after slurry deposition. Higher slurry viscosity is found to strongly restrain particle redistribution.« less

Biocalcifying Bacillus subtilis cells effectively consolidate deteriorated Globigerina limestone.

PubMed

Micallef, Roderick; Vella, Daniel; Sinagra, Emmanuel; Zammit, Gabrielle

2016-07-01

Microbially induced calcite precipitation occurs naturally on ancient limestone surfaces in Maltese hypogea. We exploited this phenomenon and treated deteriorated limestone with biocalcifying bacteria. The limestone was subjected to various mechanical and physical tests to present a statistically robust data set to prove that treatment was indeed effective. Bacillus subtilis conferred uniform bioconsolidation to a depth of 30 mm. Drilling resistance values were similar to those obtained for freshly quarried limestone (9 N) and increased up to 15 N. Treatment resulted in a high resistance to salt deterioration and a slow rate of water absorption. The overall percentage porosity of treated limestone varied by ±6 %, thus the pore network was preserved. We report an eco-friendly treatment that closely resembles the mineral composition of limestone and that penetrates into the porous structure without affecting the limestones' natural properties. The treatment is of industrial relevance since it compares well with stone consolidants available commercially.

Interaction, transformation and toxicity assessment of particles and additives used in the semiconducting industry.

PubMed

Dumitrescu, Eduard; Karunaratne, Dinusha P; Babu, S V; Wallace, Kenneth N; Andreescu, Silvana

2018-02-01

Chemical mechanical planarization (CMP) is a widely used technique for the manufacturing of integrated circuit chips in the semiconductor industry. The process generates large amounts of waste containing engineered particles, chemical additives, and chemo-mechanically removed compounds. The environmental and health effects associated with the release of CMP materials are largely unknown and have recently become of significant concern. Using a zebrafish embryo assay, we established toxicity profiles of individual CMP particle abrasives (SiO 2 and CeO 2 ), chemical additives (hydrogen peroxide, proline, glycine, nicotinic acid, and benzotriazole), as well as three model representative slurries and their resulting waste. These materials were characterized before and after use in a typical CMP process in order to assess changes that may affect their toxicological profile and alter their surface chemistry due to polishing. Toxicity outcome in zebrafish is discussed in relation with the physicochemical characteristics of the abrasive particles and with the type and concentration profile of the slurry components pre and post-polishing, as well as the interactions between particle abrasives and additives. This work provides toxicological information of realistic CMP slurries and their polishing waste, and can be used as a guideline to predict the impact of these materials in the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

An investigation into the effects of different existing states of aluminum isopropoxide on copper-based catalysts for direct synthesis of dimethyl ether from syngas

NASA Astrophysics Data System (ADS)

Sun, Kai; Wang, Peng; Bian, Zhongkai; Huang, Wei

2018-01-01

Aluminum isopropoxide (AIP) is a vital raw material to produce high surface area alumina catalyst, which is used for catalytic applications, such as hydrocracking, Fischer-Tropsch and STD (syngas to dimethyl ether) reactions. However, the different existing states have an effect on hydrolysis and condensation in the process of precursor preparation. The Cu/Zn/Al slurry catalysts were prepared by aluminum isopropoxide, which were liquid state, crystalline state and solid state, utilizing a complete liquid phase preparation technology. In the dimethyl ether (DME) synthesis reaction, the aluminum resource of crystalline state was prepared for slurry catalyst, which presented high CO conversion and DME selectivity of 54.32% and 69.74%, respectively. Characterization results indicated that different forms of AIP have the variant coordination numbers of Al-O and polymerization degrees, and the catalyst prepared by crystalline state consists amount of tetra-coordinated Al and few hexa-coordinated Al, which can exert different hydrolysis and condensation process compared with other aluminum sources, and finally it contributes to the strong interaction between active site copper species and Zn/Al species, confirming more Cu+ is responsible for the synthesis of DME in the slurry reactor.

Interactions between phosphorus feeding strategies for pigs and dairy cows and separation efficiency of slurry.

PubMed

Sommer, S G; Maahn, M; Poulsen, H D; Hjorth, M; Sehested, J

2008-01-01

Phosphorus (P) in manure is a nutrient source for plants, but surplus P amended to fields represents a risk to the environment. This study examines the interactions between low-P diets for pigs and dairy cows and the separation of animal slurry into a solid P fraction and a liquid fraction. Replacing inorganic phosphates with phytase in pig feed reduced the concentration of P in slurry by 35%, but supplementing concentrates to dairy cows did not affect the P concentration in cattle slurry. Particle-size fractions of the slurry were not affected by these dietary changes. The amount of dry matter (DM) in the < 0.025 mm fraction was greater in pig slurry than in cattle slurry, but the relative amounts of P and nitrogen (N) were larger in the > 0.025 mm fraction. Replacing feed phosphate, in the form of mono-calcium phosphate, with phytase in the pig diet reduced the separation index (efficiency) of P from 80% to 60%.

The importance of the solids loading on confirming the dielectric nanosize dependence of BaTiO₃ powders by slurry method.

PubMed

Zhou, Wei; Nie, Yi Mei; Li, Shu Jing; Liang, Hai Yan

2013-01-01

The dielectric nanosize dependence of BaTiO₃ powders was investigated by the slurry method, where two series of BaTiO₃ slurries with 10 vol% and 30 vol% solids loadings were prepared as model samples. Applying the Bruggeman-Hanai equation, the high-frequency limiting permittivity (ε(h)) of the slurries was extracted from the dielectric spectra. The ε(h) of the 10 vol% slurry showed abnormal size independence in the range from 100 nm to 700 nm, and the ε(h) of the 30 vol% slurry exhibited good agreement with the previous prediction. Through analysing quantitatively the response of ε(h) to the changing permittivity of the powders under different solids loading, it was found that the ε h of the slurry with lower solids loading is more inclined to be interfered by the systematic and random errors. Furthermore, a high permittivity value was found in the BaTiO₃ powders with 50 nm particle size.

Nitrogen and phosphorus removal coupled with carbohydrate production by five microalgae cultures cultivated in biogas slurry.

PubMed

Tan, Fen; Wang, Zhi; Zhouyang, Siyu; Li, Heng; Xie, Youping; Wang, Yuanpeng; Zheng, Yanmei; Li, Qingbiao

2016-12-01

In this study, five microalgae strains were cultured for their ability to survive in biogas slurry, remove nitrogen resources and accumulate carbohydrates. It was proved that five microalgae strains adapted in biogas slurry well without ammonia inhibition. Among them, Chlorella vulgaris ESP-6 showed the best performance on carbohydrate accumulation, giving the highest carbohydrate content of 61.5% in biogas slurry and the highest ammonia removal efficiency and rate of 96.3% and 91.7mg/L/d respectively in biogas slurry with phosphorus and magnesium added. Additionally, the absence of phosphorus and magnesium that can be adverse for biomass accumulation resulted in earlier timing of carbohydrate accumulation and magnesium was firstly recognized and proved as the influence factor for carbohydrate accumulation. Microalgae that cultured in biogas slurry accumulated more carbohydrate in cell, making biogas slurry more suitable medium for the improvement of carbohydrate content, thus can be regarded as a new strategy to accumulate carbohydrate. Copyright © 2016 Elsevier Ltd. All rights reserved.

Medical ice slurry production device

DOEpatents

Kasza, Kenneth E [Palos Park, IL; Oras, John [Des Plaines, IL; Son, HyunJin [Naperville, IL

2008-06-24

The present invention relates to an apparatus for producing sterile ice slurries for medical cooling applications. The apparatus is capable of producing highly loaded slurries suitable for delivery to targeted internal organs of a patient, such as the brain, heart, lungs, stomach, kidneys, pancreas, and others, through medical size diameter tubing. The ice slurry production apparatus includes a slurry production reservoir adapted to contain a volume of a saline solution. A flexible membrane crystallization surface is provided within the slurry production reservoir. The crystallization surface is chilled to a temperature below a freezing point of the saline solution within the reservoir such that ice particles form on the crystallization surface. A deflector in the form of a reciprocating member is provided for periodically distorting the crystallization surface and dislodging the ice particles which form on the crystallization surface. Using reservoir mixing the slurry is conditioned for easy pumping directly out of the production reservoir via medical tubing or delivery through other means such as squeeze bottles, squeeze bags, hypodermic syringes, manual hand delivery, and the like.

Prognostics of slurry pumps based on a moving-average wear degradation index and a general sequential Monte Carlo method

NASA Astrophysics Data System (ADS)

Wang, Dong; Tse, Peter W.

2015-05-01

Slurry pumps are commonly used in oil-sand mining for pumping mixtures of abrasive liquids and solids. These operations cause constant wear of slurry pump impellers, which results in the breakdown of the slurry pumps. This paper develops a prognostic method for estimating remaining useful life of slurry pump impellers. First, a moving-average wear degradation index is proposed to assess the performance degradation of the slurry pump impeller. Secondly, the state space model of the proposed health index is constructed. A general sequential Monte Carlo method is employed to derive the parameters of the state space model. The remaining useful life of the slurry pump impeller is estimated by extrapolating the established state space model to a specified alert threshold. Data collected from an industrial oil sand pump were used to validate the developed method. The results show that the accuracy of the developed method improves as more data become available.

Geology, Ground-Water Occurrence, and Estimated Well Yields from the Mariana Limestone, Kagman Area, Saipan, Commonwealth of the Northern Mariana Islands

USGS Publications Warehouse

Hoffmann, John P.; Carruth, Rob; Meyer, William

1998-01-01

A study of the geology, ground-water occurrence, and estimated well yields from the Mariana Limestone was done to investigate ground-water availability in the Kagman area, Saipan. The Mariana and Tagpochau Limestone formations form the major aquifer in the Kagman drainage basin. The Mariana Limestone, which is the major water-bearing unit in the Kagman area, ranges in thickness from 300 to 500 feet and contains intermittent, thin clay stringers. The calcareous rocks of the Tagpochau Limestone range in thickness from 500 to 1,000 feet and are more sandy than those of the Mariana Limestone. Ground water is unconfined in the Mariana Limestone and ranges from unconfined to confined in the Tagpochau Limestone. The fresh ground-water lens (that part of the lens with less than 2-percent of the chloride-ion concentration in seawater) in the Mariana Limestone is relatively thin, ranging from about 15 to 21 feet. Altitude of the water table ranges from about 1.5 to 2.5 feet above mean sea level. Freshwater in the Mariana Limestone is underlain by seawater and is separated by a transition zone about 8 to 25 feet thick. Hydraulic conductivity and transmissivity of the Mariana Limestone were calculated from data collected at six test wells. Using the Newman method, estimated hydraulic conductivity and transmissivity range from 290 to 2,500 feet per day and 7,600 to 62,000 feet squared per day, respectively. The higher values probably are indicative of average conditions in the Mariana Limestone. The estimated storage coefficient of the Mariana Limestone is about 0.1. The availability of water from the Mariana Limestone is restricted by the thinness of the freshwater lens. Results of the study indicate that fresh ground water can be obtained from the Mariana Limestone when wells are designed for minimum drawdown, effectively skimming freshwater from the top of the lens. Wells that are shallow, widely spaced, and pumped at low uniform rates can prevent saltwater intrusion. Calculated long-term yields of wells are about 30 gallons per minute or less for potable water.

Apparatus and method for pumping hot, erosive slurry of coal solids in coal derived, water immiscible liquid

DOEpatents

Ackerman, Carl D.

1983-03-29

An apparatus for and method of pumping hot, erosive slurry of coal solids in a coal derived, water immiscible liquid to higher pressure involves the use of a motive fluid which is miscible with the liquid of the slurry. The apparatus includes a pump 12, a remote check valve 14 and a chamber 16 between and in fluid communication with the pump 12 and check valve 14 through conduits 18,20. Pump 12 exerts pressure on the motive fluid and thereby on the slurry through a concentration gradient of coal solids within chamber 16 to alternately discharge slurry under pressure from the outlet port of check valve 14 and draw slurry in through the inlet port of check valve 14.

Slurry-pressing consolidation of silicon nitride

NASA Technical Reports Server (NTRS)

Sanders, William A.; Kiser, James D.; Freedman, Marc R.

1988-01-01

A baseline slurry-pressing method for a silicon nitride material is developed. The Si3N4 composition contained 5.8 wt percent SiO2 and 6.4 wt percent Y2O3. Slurry-pressing variables included volume percent solids, application of ultrasonic energy, and pH. Twenty vol percent slurry-pressed material was approximately 11 percent stronger than both 30 vol percent slurry-pressed and dry-pressed materials. The Student's t-test showed the difference to be significant at the 99 percent confidence level. Twenty volume percent (300 h) slurry-pressed test bars exhibited strengths as high as 980 MPa. Large, columnar beta-Si3N4 grains caused failure in the highest strength specimens. The improved strength correlated with better structural uniformity as determined by radiography, optical microscopy, and image analysis.

Attrition-enhanced sulfur capture by limestone particles in fluidized beds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saastamoinen, J.J.; Shimizu, T.

2007-02-14

Sulfur capture by limestone particles in fluidized beds is a well-established technology. The underlying chemical and physical phenomena of the process have been extensively studied and modeled. However, most of the studies have been focused on the relatively brief initial stage of the process, which extends from a few minutes to hours, yet the residence time of the particles in the boiler is much longer. Following the initial stage, a dense product layer will be formed on the particle surface, which decreases the rate of sulfur capture and the degree of utilization of the sorbent. Attrition can enhance sulfur capturemore » by removing this layer. A particle model for sulfur capture has been incorporated with an attrition model. After the initial stage, the rate of sulfur capture stabilizes, so that attrition removes the surface at the same rate as diffusion and chemical reaction produces new product in a thin surface layer of a particle. An analytical solution for the conversion of particles for this regime is presented. The solution includes the effects of the attrition rate, diffusion, chemical kinetics, pressure, and SO{sub 2} concentration, relative to conversion-dependent diffusivity and the rate of chemical reaction. The particle model results in models that describe the conversion of limestone in both fly ash and bottom ash. These are incorporated with the residence time (or reactor) models to calculate the average conversion of the limestone in fly ash and bottom ash, as well as the efficiency of sulfur capture. Data from a large-scale pressurized fluidized bed are compared with the model results.« less

Early diagenetic partial oxidation of organic matter and sulfides in the Middle Pennsylvanian (Desmoinesian) Excello Shale Member of the Fort Scott Limestone and equivalents, northern Midcontinent region, USA

USGS Publications Warehouse

Hatch, J.R.; Leventhal, M.S.

1997-01-01

A process of early diagenetic partial oxidation of organic matter and sulfides has altered the chemical composition of the Middle Pennsylvanian Excello Shale Member of the Fort Scott Limestone and equivalents in the northern Midcontinent region. This process was identified by comparison of organic carbon contents, Rock-Eval hydrogen indices, organic carbon ??13C and element compositions of core and surface mine samples of the Excello Shale Member with analyses of three other underlying and overlying organic-matter-rich marine shales (offshore shale lithofacies) from southern Iowa, northern Missouri, eastern Kansas and northeastern Oklahoma. The end product of the partial oxidation process is shale with relatively low contents of hydrogen-poor, C13-enriched organic matter, lower contents of sulfur and sulfide-forming elements, and relatively unchanged contents of phosphorus and many trace elements (e.g. Cr, Ni, and V). However, because of lower organic carbon contents, element/organic carbon ratios are greatly increased. The partial oxidation process apparently took place during subaerial exposure of the overlying marine carbonate member (Blackjack Creek Member of the Fort Scott Limestone) following a marine regression when meteoric waters percolated down to the level of the Excello muds allowing oxidation of organic matter and sulfides. This hypothesis is supported by earlier workers, who have identified meteoric carbonate cements within, and soil horizons at the top of the Blackjack Creek Member. The period of oxidation is constrained in that organic matter and sulfides in the Little Osage Shale Member of the Fort Scott Limestone and equivalents (immediately overlying the Blackjack Creek Member) appear unaltered. Similar alteration of other shales in the Middle and Upper Pennsylvanian sections may be local to regional in extent and would depend on the extent and duration of the marine regression and be influenced by local variations in permeability and topography. The partial oxidation process has likely led to a redistribution of sulfur and sulfide-forming elements into other organic-rich lithologies in the section. The altered/oxidized shales are nongenerative with respect to hydrocarbon generation.

Nitrification during extended co-composting of extreme mixtures of green waste and solid fraction of cattle slurry to obtain growing media.

PubMed

Cáceres, Rafaela; Coromina, Narcís; Malińska, Krystyna; Martínez-Farré, F Xavier; López, Marga; Soliva, Montserrat; Marfà, Oriol

2016-12-01

Next generation of waste management systems should apply product-oriented bioconversion processes that produce composts or biofertilisers of desired quality that can be sold in high priced markets such as horticulture. Natural acidification linked to nitrification can be promoted during composting. If nitrification is enhanced, suitable compost in terms of pH can be obtained for use in horticultural substrates. Green waste compost (GW) represents a potential suitable product for use in growing medium mixtures. However its low N provides very limited slow-release nitrogen fertilization for suitable plant growth; and GW should be composted with a complementary N-rich raw material such as the solid fraction of cattle slurry (SFCS). Therefore, it is important to determine how very different or extreme proportions of the two materials in the mixture can limit or otherwise affect the nitrification process. The objectives of this work were two-fold: (a) To assess the changes in chemical and physicochemical parameters during the prolonged composting of extreme mixtures of green waste (GW) and separated cattle slurry (SFCS) and the feasibility of using the composts as growing media. (b) To check for nitrification during composting in two different extreme mixtures of GW and SFCS and to describe the conditions under which this process can be maintained and its consequences. The physical and physicochemical properties of both composts obtained indicated that they were appropriate for use as ingredients in horticultural substrates. The nitrification process occurred in both mixtures in the medium-late thermophilic stage of the composting process. In particular, its feasibility has been demonstrated in the mixtures with a low N content. Nitrification led to the inversion of each mixture's initial pH. Copyright © 2016 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

The project objective is to demonstrate removal of 90--95% or more of the SO{sub 2} at approximately one-half the cost of conventional scrubbing technology; and to demonstrate significant reduction of space requirements. In this project, Pure Air has built a single SO{sub 2} absorber for a 528-MWe power plant. The absorber performs three functions in a single vessel: prequencher, absorber, and oxidation of sludge to gypsum. Additionally, the absorber is of a co- current design, in which the flue gas and scrubbing slurry move in the same direction and at a relatively high velocity compared to conventional scrubbers. These featuresmore » all combine to yield a state- of-the-art SO{sub 2} absorber that is more compact and less expensive than conventional scrubbers. The project incorporated a number of technical features including the injection of pulverized limestone directly into the absorber, a device called an air rotary sparger located within the base of the absorber, and a novel wastewater evaporation system. The air rotary sparger combines the functions of agitation and air distribution into one piece of equipment to facilitate the oxidation of calcium sulfite to gypsum. Additionally, wastewater treatment is being demonstrated to minimize water disposal problems inherent in many high-chloride coals. Bituminous coals primarily from the Indiana, Illinois coal basin containing 2--4.5% sulfur were tested during the demonstration. The Advanced Flue Gas Desulfurization (AFGD) process has demonstrated removal of 95% or more of the SO{sub 2} while providing a commercial gypsum by-product in lieu of solid waste. A portion of the commercial gypsum is being agglomerated into a product known as PowerChip{reg_sign} gypsum which exhibits improved physical properties, easier flowability and more user friendly handling characteristics to enhance its transportation and marketability to gypsum end-users.« less

Effects of dairy slurry on silage fermentation characteristics and nutritive value of alfalfa.

PubMed

Coblentz, W K; Muck, R E; Borchardt, M A; Spencer, S K; Jokela, W E; Bertram, M G; Coffey, K P

2014-11-01

Dairy producers frequently ask questions about the risks associated with applying dairy slurry to growing alfalfa (Medicago sativa L.). Our objectives were to determine the effects of applying dairy slurry on the subsequent nutritive value and fermentation characteristics of alfalfa balage. Dairy slurry was applied to 0.17-ha plots of alfalfa; applications were made to the second (HARV1) and third (HARV2) cuttings during June and July of 2012, respectively, at mean rates of 42,400 ± 5271 and 41,700 ± 2397 L/ha, respectively. Application strategies included (1) no slurry, (2) slurry applied directly to stubble immediately after the preceding harvest, (3) slurry applied after 1 wk of post-ensiled regrowth, or (4) slurry applied after 2 wk of regrowth. All harvested forage was packaged in large, rectangular bales that were ensiled as wrapped balage. Yields of DM harvested from HARV1 (2,477 kg/ha) and HARV2 (781 kg/ha) were not affected by slurry application treatment. By May 2013, all silages appeared to be well preserved, with no indication of undesirable odors characteristic of clostridial fermentations. Clostridium tyrobutyricum, which is known to negatively affect cheese production, was not detected in any forage on either a pre- or post-ensiled basis. On a pre-ensiled basis, counts for Clostridium cluster 1 were greater for slurry-applied plots than for those receiving no slurry, and this response was consistent for HARV1 (4.44 vs. 3.29 log10 genomic copies/g) and HARV2 (4.99 vs. 3.88 log10 genomic copies/g). Similar responses were observed on a post-ensiled basis; however, post-ensiled counts also were greater for HARV1 (5.51 vs. 5.17 log10 genomic copies/g) and HARV2 (5.84 vs. 5.28 log10 genomic copies/g) when slurry was applied to regrowth compared with stubble. For HARV2, counts also were greater following a 2-wk application delay compared with a 1-wk delay (6.23 vs. 5.45 log10 genomic copies/g). These results suggest that the risk of clostridial fermentations in alfalfa silages is greater following applications of slurry. Based on pre- and post-ensiled clostridial counts, applications of dairy slurry on stubble are preferred (and less risky) compared with delayed applications on growing alfalfa. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Morphodynamics of Travertine Dam/Waterfall Growth due to the Interaction of Biological Activity, Water Flow and Limestone Emplacement

NASA Astrophysics Data System (ADS)

Izumi, N.; Parker, G.

2012-12-01

Plitvice Lakes in Croatia are characterized by a step-like train of lakes and waterfalls. The waterfalls are located at the crests of naturally-emplaced dams. The top of each dam grows upward at the rate of a few millimeters per year. It is thought that the upward growth of these dams is caused by the interaction of water flow and biological activity, resulting in the precipitation of dissolved limestone. Dam evolution is initiated by the growth of mosses that favor swift, shallow water. Bacteria that inhabit the roots of the moss excrete solid limestone (travertine) from the water. The limestone fossilizes the moss, and then more moss grows on top of the travertine deposit. In this way, the natural dam can grow over to 10 m high, impounding the water behind it to form a lake. We propose a simple model to explain the formation of natural limestone dams by the interaction between water flow and biologically-mediated travertine deposition. We assume for simplicity that light is the only factor determining the growth of moss, which is then colonized by travertine-emplacing bacteria. We also assume that the water is saturated with dissolved limestone, so that the process is not limited by limestone availability. Photosynthesis, and thus the growth rate of moss are crudely approximated as decreasing linearly with depth. We employ the shallow water equations to describe water flow over the dam. In order to obtain a profile of permanent form for a dam migrating upward and downstream at constant speed, we solve the problem in a moving coordinate system. When water flows over the dam, it is accelerated in the streamwise direction, and the water surface forms a backwater curve. The flow regime changes from Froude-subcritical to Froude-supercritical at a point slightly downstream of the crest of the dam. Farther downstream, the flow attains a threshold velocity beyond which moss is detached. This threshold point defines the downstream end of the active part of the dam. The analysis provides a first-order morphodynamic model of natural dam/waterfall evolution.

The new idea of transporting tailings-logs in tailings slurry pipeline and the innovation of technology of mining waste-fill method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin Yu; Wang Fuji; Tao Yan

2000-07-01

This paper introduced a new idea of transporting mine tailings-logs in mine tailings-slurry pipeline and a new technology of mine cemented filing of tailings-logs with tailings-slurry. The hydraulic principles, the compaction of tailings-logs and the mechanic function of fillbody of tailings-logs cemented by tailings-slurry have been discussed.

Methods to enhance the characteristics of hydrothermally prepared slurry fuels

DOEpatents

Anderson, Chris M.; Musich, Mark A.; Mann, Michael D.; DeWall, Raymond A.; Richter, John J.; Potas, Todd A.; Willson, Warrack G.

2000-01-01

Methods for enhancing the flow behavior and stability of hydrothermally treated slurry fuels. A mechanical high-shear dispersion and homogenization device is used to shear the slurry fuel. Other improvements include blending the carbonaceous material with a form of coal to reduce or eliminate the flocculation of the slurry, and maintaining the temperature of the hydrothermal treatment between approximately 300.degree. to 350.degree. C.

The Development of Environmentally Friendly Technologies of Using Coals and Products of Their Enrichment in the Form of Coal Water Slurries

NASA Astrophysics Data System (ADS)

Murko, Vasily; Hamalainen, Veniamin

2017-11-01

The article presents the current state of the technology for production and combustion of fuel coal water slurries in Russia and foreign countries. Experimental and industrial facilities show the technological and economic efficiency of using this technology for disposal of wastes resulting after coal processing and enrichment. The feasibility studies of use of the technology at large Kuzbass thermal power stations are presented. The possibility of solving a serious environmental problem of reducing storage of the most toxic waste of coal enrichment in the location areas of coal washing plants and coal mining enterprises is demonstrated.

Method of preparing thin porous sheets of ceramic material

DOEpatents

Swarr, Thomas E.; Nickols, Richard C.; Krasij, Myron

1987-03-24

A method of forming thin porous sheets of ceramic material for use as electrodes or other components in a molten carbonate fuel cell is disclosed. The method involves spray drying a slurry of fine ceramic particles in liquid carrier to produce generally spherical agglomerates of high porosity and a rough surface texture. The ceramic particles may include the electrode catalyst and the agglomerates can be calcined to improve mechanical strength. After slurrying with suitable volatile material and binder tape casting is used to form sheets that are sufficiently strong for further processing and handling in the assembly of a high temperature fuel cell.

Method for maximizing shale oil recovery from an underground formation

DOEpatents

Sisemore, Clyde J.

1980-01-01

A method for maximizing shale oil recovery from an underground oil shale formation which has previously been processed by in situ retorting such that there is provided in the formation a column of substantially intact oil shale intervening between adjacent spent retorts, which method includes the steps of back filling the spent retorts with an aqueous slurry of spent shale. The slurry is permitted to harden into a cement-like substance which stabilizes the spent retorts. Shale oil is then recovered from the intervening column of intact oil shale by retorting the column in situ, the stabilized spent retorts providing support for the newly developed retorts.

Method of preparing thin porous sheets of ceramic material

DOEpatents

Swarr, T.E.; Nickols, R.C.; Krasij, M.

1984-05-23

A method of forming thin porous sheets of ceramic material for use as electrodes or other components in a molten carbonate fuel cell is disclosed. The method involves spray drying a slurry of fine ceramic particles in liquid carrier to produce generally spherical agglomerates of high porosity and a rough surface texture. The ceramic particles may include the electrode catalyst and the agglomerates can be calcined to improve mechanical strength. After slurrying with suitable volatile material and binder tape casting is used to form sheets that are sufficiently strong for further processing and handling in the assembly of a high temperature fuel cell.

Impacts of zeolite, alum and polyaluminum chloride amendments mixed with agricultural wastes on soil column leachate, and CO2 and CH4 emissions.

PubMed

Murnane, J G; Fenton, O; Healy, M G

2018-01-15

This study aimed to quantify leaching losses of nitrogen (N), phosphorus (P) and carbon (C), as well as carbon dioxide (CO 2 ) and methane (CH 4 ) emissions from stored slurry, and from packed soil columns surface applied with unamended and chemically amended dairy and pig slurries, and dairy soiled water (DSW). The amendments to the slurries, which were applied individually and together, were: polyaluminum chloride (PAC) and zeolite for pig and dairy slurry, and liquid aluminium sulfate (alum) and zeolite for DSW. Application of pig slurry resulted in the highest total nitrogen (TN) and nitrate-nitrogen (NO 3 -N) fluxes (22 and 12 kg ha -1 ), whereas corresponding fluxes from dairy slurries and DSW were not significantly (p < 0.05) higher than those from the control soil. There were no significant (p < 0.05) differences in leachate N losses between unamended and amended dairy slurries, unamended and amended pig slurries, and unamended and amended DSW. There were no leachate P losses measured over the experimental duration. Total cumulative organic (TOC) and inorganic C (TIC) losses in leachate were highest for unamended dairy slurry (82 and 142 kg ha -1 ), and these were significantly (p < 0.05) reduced when amended with PAC (38 and 104 kg ha -1 ). The highest average cumulative CO 2 emissions for all treatments were measured for pig slurries (680 kg CO 2 -C ha -1 ) followed by DSW (515 kg CO 2 -C ha -1 ) and dairy slurries (486 kg CO 2 -C ha -1 ). The results indicate that pig slurry, either in raw or chemically amended form, poses the greatest environmental threat of leaching losses and gaseous emissions of CO 2 and CH 4 and, in general, amendment of wastewater with PAC, alum or zeolite, does not mitigate the risk of these losses. Copyright © 2017 Elsevier Ltd. All rights reserved.

Insensitive explosive composition of halogenated copolymer and triaminotrinitrobenzene

DOEpatents

Benziger, Theodore M.

1976-01-01

A highly insensitive and heat resistant plastic-bonded explosive containing 90 wt % triaminotrinitrobenzene and 10 wt % of a fully saturated copolymer of chlorotrifluoroethylene and vinylidene fluoride is readily manufactured by the slurry process.

Oxidation resistant slurry coating for carbon-based materials

NASA Technical Reports Server (NTRS)

Smialek, J. L.; Rybicki, G. C. (Inventor)

1985-01-01

An oxidation resistant coating is produced on carbon-base materials, and the same processing step effects an infiltration of the substrate with silicon containing material. The process comprises making a slurry of nickel and silicon powders in a nitrocellulose lacquer, spraying onto the graphite or carbon-carbon substrate, and sintering in vacuum to form a fused coating that wets and covers the surface as well as penetrates into the pores of the substrate. Optimum wetting and infiltration occurs in the range of Ni-60 w/o Si to Ni-90 w/o Si with deposited thicknesses of 25-100 mg/sq. cm. Sintering temperatures of about 1200 C to about 1400 C are used, depending on the melting point of the specific coating composition. The sintered coating results in Ni-Si intermetallic phases and SiC, both of which are highly oxidation resistant.

Morphological transformation during activation and reaction of an iron Fischer-Tropsch catalyst

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jackson, N.B.; Kohler, S.; Harrington, M.

1995-12-31

The purpose of this project is to support the development of slurry-phase bubble column processes being studied at the La Porte Alternative Fuel Development Unit. This paper describes the aspects of Sandia`s recent work regarding the advancement and understanding of the iron catalyst used in the slurry phase process. A number of techniques were used to understand the chemical and physical effects of pretreatment and reaction on the attrition and carbon deposition characteristics of iron catalysts. Unless otherwise stated, the data discussed was derived form experiments carried out on the catalyst chosen for the summer 1994 Fischer-Tropsch run at LaPorte,more » UCI 1185-78-370, (an L 3950 type) that is 88% Fe{sub 2}O{sub 3}, 11% CuO, and 0.052%K{sub 2}O.« less

The Impact of Using Alternative Forages on the Nutrient Value within Slurry and Its Implications for Forage Productivity in Agricultural Systems

PubMed Central

Crotty, Felicity V.; Fychan, Rhun; Theobald, Vince J.; Sanderson, Ruth; Chadwick, David R.; Marley, Christina L.

2014-01-01

Alternative forages can be used to provide valuable home-grown feed for ruminant livestock. Utilising these different forages could affect the manure value and the implications of incorporating these forages into farming systems, needs to be better understood. An experiment tested the hypothesis that applying slurries from ruminants, fed ensiled red clover (Trifolium pratense), lucerne (Medicago sativa) or kale (Brassica oleracea) would improve the yield of hybrid ryegrass (Lolium hybridicum), compared with applying slurries from ruminants fed ensiled hybrid ryegrass, or applying inorganic N alone. Slurries from sheep offered one of four silages were applied to ryegrass plots (at 35 t ha−1) with 100 kg N ha−1 inorganic fertiliser; dry matter (DM) yield was compared to plots only receiving ammonium nitrate at rates of 0, 100 and 250 kg N ha−1 year−1. The DM yield of plots treated with 250 kg N, lucerne or red clover slurry was significantly higher than other treatments (P<0.001). The estimated relative fertiliser N equivalence (FNE) (fertiliser-N needed to produce same yield as slurry N), was greatest for lucerne (114 kg) >red clover (81 kg) >kale (44 kg) >ryegrass (26 kg ha−1 yr−1). These FNE values represent relative efficiencies of 22% (ryegrass), 52% (kale), 47% (red clover) and 60% for lucerne slurry, with the ryegrass slurry efficiency being lowest (P = 0.005). Soil magnesium levels in plots treated with legume slurry were higher than other treatments (P<0.001). Overall, slurries from ruminants fed alternative ensiled forages increased soil nutrient status, forage productivity and better N efficiency than slurries from ruminants fed ryegrass silage. The efficiency of fertiliser use is one of the major factors influencing the sustainability of farming systems, these findings highlight the cascade in benefits from feeding ruminants alternative forages, and the need to ensure their value is effectively captured to reduce environmental risks. PMID:24830777

Bacterial community dynamics in long-term operation of a pilot plant using aerobic granular sludge to treat pig slurry.

PubMed

Fra-Vázquez, A; Morales, N; Figueroa, M; Val Del Río, A; Regueiro, L; Campos, J L; Mosquera-Corral, A

2016-09-01

Aerobic granular sludge represents an interesting approach for simultaneous organic matter and nitrogen removal in wastewater treatment plants. However, the information about microbial communities in aerobic granular systems dealing with industrial wastewater like pig slurry is limited. Herein, bacterial diversity and dynamics were assessed in a pilot scale plant using aerobic granular sludge for organic matter and nitrogen elimination from swine slurry during more than 300 days. Results indicated that bacterial composition evolved throughout the operational period from flocculent activated sludge, used as inoculum, to mature aerobic granules. Bacterial diversity increased at the beginning of the granulation process and then declined due to the application of transient organic matter and nitrogen loads. The operational conditions of the pilot plant and the degree of granulation determined the microbial community of the aerobic granules. Brachymonas, Zoogloea and Thauera were attributed with structural function as they are able to produce extracellular polymeric substances to maintain the granular structure. Nitrogen removal was justified by partial nitrification (Nitrosomonas) and denitrification (Thauera and Zoogloea), while Comamonas was identified as the main organic matter oxidizing bacteria. Overall, clear links between bacterial dynamics and composition with process performance were found and will help to predict their biological functions in wastewater ecosystems improving the future control of the process. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1212-1221, 2016. © 2016 American Institute of Chemical Engineers.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poirier, M.; Burket, P.

The Savannah River Site (SRS) is currently treating radioactive liquid waste with the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). Recently, the low filter flux through the ARP of approximately 5 gallons per minute has limited the rate at which radioactive liquid waste can be treated. Salt Batch 6 had a lower processing rate and required frequent filter cleaning. Savannah River Remediation (SRR) has a desire to understand the causes of the low filter flux and to increase ARP/MCU throughput. SRR requested SRNL to conduct bench-scale filter tests to evaluate whether sodium oxalate, sodiummore » aluminosilicate, or aluminum solids (i.e., gibbsite and boehmite) could be the cause of excessive fouling of the crossflow or secondary filter at ARP. The authors conducted the tests by preparing slurries containing 6.6 M sodium Salt Batch 6 supernate, 2.5 g MST/L slurry, and varying concentrations of sodium oxalate, sodium aluminosilicate, and aluminum solids, processing the slurry through a bench-scale filter unit that contains a crossflow primary filter and a dead-end secondary filter, and measuring filter flux and transmembrane pressure as a function of time. Among the conclusions drwn from this work are the following: (1) All of the tests showed some evidence of fouling the secondary filter. This fouling could be from fine particles passing through the crossflow filter. (2) The sodium oxalate-containing feeds behaved differently from the sodium aluminosilicate- and gibbsite/boehmite-containing feeds.« less

Modelling ammonia volatilization from animal slurry applied with trail hoses to cereals

NASA Astrophysics Data System (ADS)

Sommer, S. G.; Olesen, J. E.

In Europe ammonia (NH 3), volatilization from animal manure is the major source of NH 3 in the atmosphere. From March to July 1997, NH 3 volatilization from trail hose applied slurry was measured for seven days after application in six experiments. A statistical analysis of data showed that NH 3 volatilization rate during the first 4-5 h after slurry application increased significantly ( P<5%) with wind speed and soil slurry surface water content. NH 3 volatilization in the six measuring periods during the experiments increased significantly ( P<5%) with relative water content of the soil slurry surface, global radiation, pH, and decreased with increasing rainfall during each measuring period and rainfall accumulated from onset of each experiment. A mechanistic model of NH 3 volatilization was developed. Model inputs are climate variables, soil characteristics and total ammoniacal nitrogen (TAN=ammonium+ammonia) in the soil surface layer. A pH submodel for predicting pH at the surface of the soil slurry liquid was developed. The measured NH 3 volatilization was compared with model simulations. The simulated results explained 27% of the variation in measured NH 3 volatilization rates during all seven days, but 48% of measured volatilization rates during the first 24 h. Calculations with the model showed that applying slurry in the morning or in the afternoon reduced volatilization by 50% compared with a noon application. Spreading the slurry with trail hoses to a 60 cm high crop reduced losses by 75% compared with a spreading onto bare soil. Ammonia volatilization was 50% lower when the soil had dried out after slurry application compared with a wet slurry surface.