Science.gov

Sample records for air addition sosub

  1. Effects of SO/sub 2/ shielding gas additions on GTA weld shape

    SciTech Connect

    Heiple, C.R.; Burgardt, P.

    1985-06-01

    Substantial increases in GTA weld depth/width ratio resulted from small additions of sulfur dioxide (SO/sub 2/) to the torch shielding gas when welding two stainless steels. The improvement was demonstrated on both Types 304 and 21-6-9 austenitic stainless steels, but would be expected for iron-base alloys generally. The weld pool shape achieved was essentially independent of variations in both SO/sub 2/ content of the torch gas and base metal composition when SO/sub 2/ in the shielding gas was in the range of 500 to 1400 ppm. With 700 ppm SO/sub 2/ in the torch gas, less than 30 ppm sulfur was added to an autogenous weld bead. For alloys where this additional sulfur can be tolerated and appropriate measures can be taken to handle the toxic SO/sub 2/, this technique offers a promising way to improve GTA weld joint penetration while suppressing variable penetration.

  2. Rapid air titration method for determining SO/sub 2/ concentration in inhalation chambers

    SciTech Connect

    Snyder, E.A.; Palmes, E.D.

    1985-06-01

    A rapid air titration method for determining SO/sub 2/ concentration in inhalation chambers has been validated using the pararosaniline-formaldehyde (PRA) method of West and Gaeke. This air-titration (iodate) method is an adaptation of iodometric methods using a starch indicator. Potassium iodate and an excess of potassium iodide are used in the reaction. Sampling is completed in ten minutes or less and concentration is calculated by use of a simple formula. Linear equations were derived over the range of concentrations from 0.5 to 100 ppm SO/sub 2/ for uncorrected iodate bubbler results, data corrected for tandem bubbler concentrations and data corrected for mean iodate bubbler efficiency. Linear correlation with the PRA method over this range was 0.999 for all three sets of data.

  3. SO{sub 2} uptake on ice spheres: Liquid nature of the ice-air interface

    SciTech Connect

    Conklin, M.H.; Bales, R.C.

    1993-09-20

    The amount of SO{sub 2} gas absorbed by ice of known surface area at equilibrium was used to estimate the volume of liquid water present at the ice-air interface at temperatures from {minus}1 to {minus}60{degrees}C. Calculations were based on Henry`s law and acid dissociation equilibrium. The liquid volume is lowest at lower temperatures and ionic strength and under most conditions was greater than the volumes calculated based on freezing-point depression. The equivalent layer thickness, assuming that liquid water is uniformly distributed around the grains, ranged from 3-30 nm at {minus}60{degrees}C to 500-3000 nm at {minus}1{degrees}C. Corresponding ionic strengths for the two temperatures were 1.7-0.0012 M and 0.005-0.00009 M. Lower values were for ice made from distilled water, and higher values were for ice made from 10{sup {minus}3} M NaCl. Estimated pH values were from 2.9 at {minus}60{degrees}C to 4.1 at {minus}1{degrees}C. Results demonstrate that gas absorption can be used to estimate an equivalent liquid volume and thickness for the ice-air interfacial region. While not directly comparable to physical measurements, the estimated values should be directly applicable to modeling uptake of SO{sub 2} and other trace gases by ice. Lack of good thermodynamic data for temperature below 0{degrees}C is the main limitation to applying this method. 23 refs., 3 figs., 1 tab.

  4. High SO{sub 2} removal efficiency testing. Topical report - results of sodium formate additive tests at New York State Electric & Gas Corporation`s Kintigh Station

    SciTech Connect

    Murphy, J.

    1997-02-14

    Tests were conducted at New York State Gas & Electric`s (NYSEG`s) Kintigh Station to evaluate options for achieving high sulfur dioxide (SO{sub 2}) removal efficiency in the wet limestone flue gas desulfurization (FGD) system. This test program was one of six conducted by the U.S. Department of Energy to evaluate low-capital-cost upgrades to existing FGD systems as a means for utilities to comply with the requirements of the 1990 Clean Air Act Amendments. The upgrade option tested at Kintigh was sodium formate additive. Results from the tests were used to calibrate the Electric Power Research Institute`s (EPRI) FGD PRocess Integration and Simulation Model (FGDPRISM) to the Kintigh scrubber configuration. FGDPRISM was then used to predict system performance for evaluating conditions other than those tested. An economic evaluation was then done to determine the cost effectiveness of various high-efficiency upgrade options. These costs can be compared with the estimated market value of SO{sub 2} allowance or the expected costs of allowances generated by other means, such as fuel switching or new scrubbers, to arrive at the most cost-effective strategy for Clean Air Act compliance.

  5. Buffer additives, Mg-lime improve SO/sub 2/ scrubber performance

    SciTech Connect

    Smock, R.

    1982-08-01

    Demonstrations indicate that adipic acid and other organic buffering agents can improve the performance of limestone scrubbers for utilities using high-sulfur coal. Organic buffers used during the nine-month demonstration boosted the efficiency of sulfur dioxide (SO/sub 2/) removal from 70% to 95%. Despite legal incentives, the results are consistent with other industrial-scale and pilot-plant tests. Dibasic acids (DBA) had similar results. The low cost of buffer enhancing makes it a low-risk investment for utilities that need to bring their scrubbers into compliance with environmental standards. Scrubbers using adipic acid reduce capital costs 10% below conventional designs and annual operating costs 11%. 1 figure, 6 tables. (DCK)

  6. An analysis of SO{sub 2} emission compliance under the 1990 Clean Air Act Amendments

    SciTech Connect

    Hanson, D.A.; Cilek, C.M.; Pandola, G.; Taxon, T.

    1992-07-01

    The effectiveness of SO{sub 2} emission allowance trading under Title 4 of the 1990 Amendments to the Clean Air Act (CAA) is of great interest due to the innovative nature of this market incentive approach. However, it may be a mistake to frame the compliance problem for a utility as a decision to trade or not. Trading of allowances should be the consequence, not the decision. The two meaningful decision variables for a utility are the control approaches chosen for its units and the amount of allowances to hold in its portfolio of assets for the future. The number allowances to be bought or sold (i.e. traded) is determined by the emission reduction and banking decisions. Our preferred approach is to think of the problem in terms of ABC`s of the 1990 CAA Amendments: abatement strategy, banking, and cost competitiveness. The implications of the general principles presented in this paper on least cost emission reductions and emissions banking to hedge against risk are being simulated with version 2 of the ARGUS model representing the electric utility sector and regional coal supplies and transportation rates. A rational expectations forecast for allowances prices is being computed. The computed allowance price path has the property that demand for allowances by electric utilities for current use or for banking must equal the supply of allowances issued by the federal government or provided as forward market contracts in private market transactions involving non-utility speculators. From this rational expectations equilibrium forecast, uncertainties are being explored using sensitivity tests. Some of the key issues are the amount of scrubbing and when it is economical to install it, the amount of coal switching and how much low sulfur coal premiums will be bid up; and the amount of emission trading within utilities and among different utilities.

  7. Effect of Li{sub 2}SO{sub 4} addition on structure and ionic conductivity of lithium borosilicotitanate glasses

    SciTech Connect

    Satpute, N. S.; Deshpande, A. V.

    2014-04-24

    Lithium borosilicotitanate glasses containing Li{sub 2}SO{sub 4} were prepared by melt quenching technique. Electrical conductivity, density, molar volume and glass transition temperature T{sub g} for all the glass samples were measured. IR spectroscopy was used for structural studies of these glasses in the range from 400 to 2000 cm{sub −1}. The conductivity of the Li{sub 2}SO{sub 4} containing glasses was found to be half an order higher than the base glass. The electrical conductivity was interpreted from the point of view of glass structure which suggests that an enhancement in conductivity is due to the incorporation of Li{sub 2}SO{sub 4} in the macromolecular network. The molar volume and glass transition temperature T{sub g} results are found to be in good correlation with conductivity results.

  8. Phytotoxicity of air pollutants: evidence for the photodetoxification of SO/sub 2/ but not O/sub 3/

    SciTech Connect

    Olszyk, D.M.; Tingey, D.T.

    1984-04-01

    Pisum sativum L. cv Alsweet (garden pea) and Lycopersicon esculentum flacca Mill. (tomato) were used to evaluate the phytotoxicity of SO/sub 2/ and O/sub 3/ in the light and dark. Plants were grown in controlled environment chambers and exposed to SO/sub 2/ or O/sub 3/ in the light or dark at the same environmental conditions at which they were grown. The pea plants were treated with fusicoccin to ensure open stomata in the dark; the stomata of the tomato mutant remained open in the dark. Both species exhibited 64% to 80% less foliar necrosis following exposure to SO/sub 2/ (0.5 to 1.0 microliter per liter for 2 hours) in the light than in the dark. The decrease in SO/sub 2/ injury for light versus dark exposed plants was greater in fully expanded than expanding leaves. Both species exhibited 30% greater foliar necrosis following exposure to O/sub 3/ (0.2 microliter per liter for 2 hours) in the light than dark. The increase in O/sub 3/ injury in the light versus dark was similar for leaves at all stages of expansion. Leaf conductance to water vapor was 7% to 11% and 23% higher in the light than dark for fusicoccin-treated peas and tomato plants, respectively, indicating greater foliar uptake of both pollutants in the light than dark. Thus, the decrease SO/sub 2/ toxicity in the light was not associated with pollutant uptake, but rather the metabolism of SO/sub 2/. In contrast, the increased toxicity of O/sub 3/ in the light was at least in part associated with increased uptake or could not be separated from it.

  9. Observational study on the concentration distributions of SO{sub 2} and NO{sub 2} in Dhaka, Bangladesh under severe air pollution condition in winter

    SciTech Connect

    Azad, A.K.; Kitada, T.

    1996-12-31

    Dhaka is the capital and the biggest city of Bangladesh, and is expanding very rapidly. Emissions from heavy traffic and many small industries and commercial complexes, newly developed in and around the city, are polluting the air of Dhaka city. The air pollution is severe especially in winter due to adverse meteorological conditions such as low wind speed and dry, stably-stratified air, which restricts the mixing height to low levels and prevent dispersion of pollutants. But so far no study of air pollution of Dhaka city has been done. We have first measured SO{sub 2} and NO{sub 2} concentrations in Dhaka city in a large scale and derived their spatial distributions over Dhaka. Molecular diffusion tubes, which do not require power sources and are produced at low cost, have been used to measure the concentration distributions of SO{sub 2} and NO{sub 2} at 64 sites in Dhaka city and its suburbs during the period of December-January of 1995-96. The diffusion tube samplers were calibrated using 6 automated air pollution monitoring stations in Aichi-prefecture, Japan. The calibration curve and the distribution of the concentration data acquired by automatic measurement instrument at each location showed that the error range of measurements with the molecular diffusion tube samplers was 2-27%. The samples were analyzed using ion-chromatography and spectrophotometer to determine the concentrations of SO{sub 2} and NO{sub 2} respectively. The contamination of unexposed tubes under field conditions was determined and the value of the blank test was subtracted from the measurements of the diffusion tube samplers. The effects of wind turbulence and temperature were reduced using polyflon filters.

  10. Combined SO{sub 2}/NO{sub x} control using ferrous{center_dot}EDTA and a secondary additive in a lime-based aqueous scrubber system

    SciTech Connect

    Mendelsohn, M.H.; Livengood, C.D.; Harkness, J.B.L.

    1991-12-01

    Integration of NO{sub x} control into existing flue-gas desulfurization (FGD) systems addresses site-specific control requirements while minimizing retrofit difficulties. Argonne has studied the use of the metal-chelate additives, such as ferrous{center_dot}EDTA in various wet FGD chemistries, to promote combined SO{sub 2}/NO{sub x} scrubbing. A major process problem is oxidation of the iron to the ferric species, leading to a significant decrease in NO{sub x}-removal capability. Argonne discovered a class of organic compounds that, when used with ferrous{center_dot}EDTA in a sodium carbonate chemistry, could maintain high levels of NO{sub x} removal. However, those antioxidant/reducing agents are not effective in a lime-based chemistry, and a broader investigation of antioxidants was initiated. This paper discusses results of that investigation, which found a practical antioxidant/reducing agent capable of maintaining NO{sub x} removals of about 50% (compared with about 15% without the agent) in a lime-based FGD chemistry with FE(II){center_dot}EDTA. 5 refs., 10 figs.

  11. Fuel additives from SO/sub 2/ treated mixtures of amides and esters derived from vegetable oil, tall oil acid, or aralkyl acid

    SciTech Connect

    Efner, H. F.; Schiff, S.

    1985-03-12

    Vegetable oils, particularly soybean oil, tall oil acid, or aralkyl acids, particularly phenylstearic acid, are reacted with multiamines, particularly tetraethylenepentamine, to form a product mixture for subsequent reaction with SO/sub 2/ to produce a product mix that has good detergent properties in fuels.

  12. SO.sub.2 sensor

    DOEpatents

    Dalla Betta, Ralph A.; Sheridan, David R.

    1994-01-01

    This invention is a process for detecting low concentration levels of sulfur oxides (SO.sub.2) in a flowing gas stream (typically a combustion exhaust gas stream) and a catalytic SO.sub.2 sensor system which may be used in that process.

  13. High SO{sub 2} removal efficiency testing: Results of DBA and sodium formate additive tests at Southwestern Electric Power company`s Pirkey Station

    SciTech Connect

    1996-05-30

    Tests were conducted at Southwestern Electric Power Company`s (SWEPCo) Henry W. Pirkey Station wet limestone flue gas desulfurization (FGD) system to evaluate options for achieving high sulfur dioxide removal efficiency. The Pirkey FGD system includes four absorber modules, each with dual slurry recirculation loops and with a perforated plate tray in the upper loop. The options tested involved the use of dibasic acid (DBA) or sodium formate as a performance additive. The effectiveness of other potential options was simulated with the Electric Power Research Institute`s (EPRI) FGD PRocess Integration and Simulation Model (FGDPRISM) after it was calibrated to the system. An economic analysis was done to determine the cost effectiveness of the high-efficiency options. Results are-summarized below.

  14. Method for treating SO/sub 2/, SO/sub 3/ and dust simultaneously

    SciTech Connect

    Shinoda, N.; Tatani, A.; Onizuka, M.; Okino, S.

    1987-09-29

    In a method of treating an exhaust gas which contains SO/sub 2/ and SO/sub 3/ and dust wherein the gas is passed through a dry dust collector to remove most of the dust, the teated gas is then treated in an absorbing device containing an absorbent selected from the group consisting of calcium hydroxide and calcium carbonate to remove SO/sub 2/ and remaining dust. The improvement this patent describes comprises the steps of blowing air into an absorbing solution fed the gas absorbing device in order to oxidize the absorbing solution and to thereby form a gypsum therein; then separating a part of the absorbing solution into a first slurry containing mainly the gypsum grains and a second slurry containing mainly the dust by utilizing the difference between the precipitation speeds of dust and gypsum particles in the slurry. Next, one obtains the gypsum from the first slurry; adds an alkali to the second slurry; sprays the alkali second slurry into the exhaust gas on the upstream side of the dry dust collector, collects dries and solidifies SO/sub 3/; and collects the resultant solid together with the dust with the dry dust collector.

  15. Metal-air cell with performance enhancing additive

    DOEpatents

    Friesen, Cody A; Buttry, Daniel

    2015-11-10

    Systems and methods drawn to an electrochemical cell comprising a low temperature ionic liquid comprising positive ions and negative ions and a performance enhancing additive added to the low temperature ionic liquid. The additive dissolves in the ionic liquid to form cations, which are coordinated with one or more negative ions forming ion complexes. The electrochemical cell also includes an air electrode configured to absorb and reduce oxygen. The ion complexes improve oxygen reduction thermodynamics and/or kinetics relative to the ionic liquid without the additive.

  16. Tracer studies of SO{sub 2} oxidation in clouds

    SciTech Connect

    Burkhard, E.G.

    1994-12-31

    The quantitative determination of aqueous phase oxidation of S(IV) is critical to determining: (1) the relationship between regional SO{sub 2} emissions and acid deposition at distant receptors; and (2) the size distribution of anthropogenic sulphate aerosols which has consequences on global climate. Husain developed a tracer technique, based on the similarities in physical and chemical behavior of SO{sub 4} and Se aerosols to quantitatively determine SO{sub 2} oxidation in clouds. Extensive investigation of the technique including verification of the assumptions, extension to develop other tracers, its application to study S(IV) oxidation in clouds, comparison of the field data with calculations based on laboratory reaction rates and an assessment of the role of clouds on SO{sub 2} oxidation were the important goals of this dissertation. Field investigations were conducted at Whiteface Mountain, New York during the summers of 1990, 1991, and 1992. Three hundred seventy cloud water samples, usually of 15 min duration were collected from thirteen clouds. Aerosol in cloud free air were also collected for each cloud system. pH of the cloud water ranged between 2.85 and 4.7. Six clouds were selected, based on chemical and meteorological conditions for determination of in-cloud SO{sub 2} oxidation. The amount of SO{sub 4} formed in situ by aqueous phase oxidation (SO{sub 4in}) ranged from none to about 40%. In three clouds, in-cloud oxidation was quantified using Se, As, and Sb as tracers. The results were in good agreement when large amounts of SO{sub 4in} were produced. It is concluded that all three, Se, As, and Sb can be used to determine SO{sub 2} oxidation in clouds. Based on SO{sub 4in}, concentrations of SO{sub 2}, H{sub 2}O{sub 2}, and laboratory reaction rates, progression of the reaction was followed in time using a simple computer model.

  17. Do-It-Yourself Additives Recharge Auto Air Conditioning

    NASA Technical Reports Server (NTRS)

    2010-01-01

    In planning for a return mission to the Moon, NASA aimed to improve the thermal control systems that keep astronauts comfortable and cool while inside a spacecraft. Goddard Space Flight Center awarded a Small Business Innovation Research (SBIR) contract to Mainstream Engineering Corporation, of Rockledge, Florida, to develop a chemical/mechanical heat pump. IDQ Inc., of Garland, Texas, exclusively licensed the technology and incorporates it into its line of Arctic Freeze products for automotive air conditioning applications. While working on the design, Mainstream Engineering came up with a unique liquid additive called QwikBoost to enhance the performance of the advanced heat pump design.

  18. An analysis of candidates for addition to the Clean Air Act list of hazardous air pollutants.

    PubMed

    Lunder, Sonya; Woodruff, Tracey J; Axelrad, Daniel A

    2004-02-01

    There are 188 air toxics listed as hazardous air pollutants (HAPs) in the Clean Air Act (CAA), based on their potential to adversely impact public health. This paper presents several analyses performed to screen potential candidates for addition to the HAPs list. We analyzed 1086 HAPs and potential HAPs, including chemicals regulated by the state of California or with emissions reported to the Toxics Release Inventory (TRI). HAPs and potential HAPs were ranked by their emissions to air, and by toxicity-weighted (tox-wtd) emissions for cancer and noncancer, using emissions information from the TRI and toxicity information from state and federal agencies. Separate consideration was given for persistent, bioaccumulative toxins (PBTs), reproductive or developmental toxins, and chemicals under evaluation for regulation as toxic air contaminants in California. Forty-four pollutants were identified as candidate HAPs based on three ranking analyses and whether they were a PBT or a reproductive or developmental toxin. Of these, nine qualified in two or three different rankings (ammonia [NH3], copper [Cu], Cu compounds, nitric acid [HNO3], N-methyl-2-pyrrolidone, sulfuric acid [H2SO4], vanadium [V] compounds, zinc [Zn], and Zn compounds). This analysis suggests further evaluation of several pollutants for possible addition to the CAA list of HAPs.

  19. Comparison of orchid and OCD modeling SO{sub x} release in the Gulf of Mexico

    SciTech Connect

    Ferris, D.C.; Burns, D.S.; Steorts, W.L.

    1996-10-01

    Two atmospheric chemistry and transport models are used to investigate the atmospheric behavior of SO{sub x} in the Gulf of Mexico. SO{sub x} emissions from a location about 30 miles offshore in the Gulf of Mexico will be modeled with ENSCO`s Short-range Layered Atmospheric Model (SLAM) and the EPA and Material Management Service (MMS) sanctioned Offshore and Coastal Dispersion Model (OCD). The atmospheric chemistry associated with SLAM is modeled using ENSCO`s ORganic CHemistry Integrated Dispersion Model (ORCHID) and has been developed from the Carbon Bond Mechanism (CBM-IV) to characterize the behavior of SO{sub x} compounds in the environment. Model runs from both ORCHID and OCD will be presented and compared. Predicted SO{sub x} concentrations will be compared with actual data gathered from the MMS`s SO{sub x} air quality study in 1993.

  20. 77 FR 65310 - Additional Air Quality Designations for the 2006 24-Hour Fine Particle National Ambient Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-26

    ... AGENCY 40 CFR Part 81 Additional Air Quality Designations for the 2006 24-Hour Fine Particle National Ambient Air Quality Standards AGENCY: Environmental Protection Agency (EPA). ACTION: Supplemental... particle (PM 2.5 ) national ambient air quality standards (NAAQS) air quality designations for the...

  1. 77 FR 11618 - Additional Guidance on Airfare/Air Tour Price Advertisements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-27

    ... Office of the Secretary Additional Guidance on Airfare/Air Tour Price Advertisements AGENCY: Office of.../air tour price advertisements. SUMMARY: The Department is publishing the following notice providing additional guidance on airfare/air tour price advertisements. FOR FURTHER INFORMATION CONTACT: Nicholas...

  2. 48 CFR 1371.103 - Additional item requirements (AIR)-growth work.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... requirements (AIR)-growth work. 1371.103 Section 1371.103 Federal Acquisition Regulations System DEPARTMENT OF... Provisions and Clauses 1371.103 Additional item requirements (AIR)—growth work. Insert clause 1352.271-72, Additional Item Requirements (AIR)—Growth Work, in all solicitations and contracts for ship repair....

  3. 48 CFR 1352.271-72 - Additional Item Requirements (AIR)-growth work

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Requirements (AIR)-growth work 1352.271-72 Section 1352.271-72 Federal Acquisition Regulations System... Clauses 1352.271-72 Additional Item Requirements (AIR)—growth work As prescribed in 48 CFR 1371.103, insert the following clause: Additional Item Requirements (Air)—Growth Work (APR 2010) (a) This...

  4. 48 CFR 1371.103 - Additional item requirements (AIR)-growth work.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... requirements (AIR)-growth work. 1371.103 Section 1371.103 Federal Acquisition Regulations System DEPARTMENT OF... Provisions and Clauses 1371.103 Additional item requirements (AIR)—growth work. Insert clause 1352.271-72, Additional Item Requirements (AIR)—Growth Work, in all solicitations and contracts for ship repair....

  5. 48 CFR 1352.271-72 - Additional Item Requirements (AIR)-growth work

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Requirements (AIR)-growth work 1352.271-72 Section 1352.271-72 Federal Acquisition Regulations System... Clauses 1352.271-72 Additional Item Requirements (AIR)—growth work As prescribed in 48 CFR 1371.103, insert the following clause: Additional Item Requirements (Air)—Growth Work (APR 2010) (a) This...

  6. EPA, California Notify Volkswagen of Additional Clean Air Act Violations

    EPA Pesticide Factsheets

    WASHINGTON - Today, EPA is issuing a second notice of violation (NOV) of the Clean Air Act (CAA) to Volkswagen AG, Audi AG and Volkswagen Group of America, Inc. This NOV is also being issued to Porsche AG and Porsche Cars North America. These five c

  7. Bifunctional air electrodes containing elemental iron powder charging additive

    DOEpatents

    Liu, Chia-tsun; Demczyk, Brian G.; Gongaware, Paul R.

    1982-01-01

    A bifunctional air electrode for use in electrochemical energy cells is made, comprising a hydrophilic layer and a hydrophobic layer, where the hydrophilic layer essentially comprises a hydrophilic composite which includes: (i) carbon; (ii) elemental iron particles having a particle size of between about 25 microns and about 700 microns diameter; (iii) an oxygen evolution material; (iv) a nonwetting agent; and (v) a catalyst, where at least one current collector is formed into said composite.

  8. High-efficiency SO{sub 2} removal in utility FGD systems

    SciTech Connect

    Phillips, J.L.; Gray, S.; Dekraker, D.

    1995-11-01

    The U.S. Department of Energy (DOE) and the Electric Power Research Institute (EPRI) have contracted with Radian Corporation to conduct full-scale testing, process modeling, and economic evaluations of six existing utility flue gas desulfurization (FGD) systems. The project objective is to evaluate low capital cost upgrades for achieving up to 98% sulfur dioxide (SO{sub 2}) removal efficiency in a variety of FGD system types. The systems include dual-loop, packed absorbers at Tampa Electric Company`s Big Bend Station; cocurrent, packed absorbers at Hoosier Energy`s Merom Station; dual-loop absorbers with perforated-plate trays at Southwestern Electric Power Company`s Pirkey Station; horizontal spray absorbers at PSI Energy`s Gibson Station; venturi scrubbers at Duquesne Light`s Elrama Station; and open stray absorbers at New york State Electric and Gas Corporations`s (NYSEG`s) Kintigh Station. All operate in an inhibited-oxidation mode except the system at Big Bend (forced oxidation), and all use limestone reagent except the Elrama system (Mg-lime). The program was conducted to demonstrate that upgrades such as performance additives and/or mechanical modifications can increase system SO{sub 2} removal at low cost. The cost effectiveness of each upgrade has been evaluated on the basis of test results and/or process model predictions for upgraded performance and utility-specific operating and maintenance costs. Results from this upgraded performance and utility-specific operating and maintenance costs. Results from this program may lead some utilities to use SO{sub 2} removal upgrades as an approach for compliance with phase 2 of Title IV of the Clean Air Act Amendments (CAAA) of 1990. This paper summarizes the results of testing, modeling, and economic evaluations that have been completed since July, 1994.

  9. Float-sink separation of coal with liquid SO/sub 2/

    SciTech Connect

    Burk, E.H.; Yoo, J.S.

    1980-04-15

    The float-sink separation of coal from pyrite and ash in a bath of liquid SO/sub 2/ is disclosed. The specific gravity of the bath may adjusted by the addition of inert materials such as miscible materials or finely divided solids. Additional separation in another dense medium may be employed. The communition, conveying and mining of coal with liquid SO/sub 2/ is also disclosed.

  10. Application of a new sorbent for combined SO{sub 2} and NO{sub x} removal. Final report

    SciTech Connect

    Nelson, S.G.

    1989-09-01

    The overall objective of this project was to further develop the application of a new class of dry, granular, SO{sub 2}/NO{sub x}-sorbent materials to bring them closer towards commercial usage in utility and industrial air-pollution control systems. The new sorbents are composite materials consisting of magnesium oxide (MgO) or calcium oxide (CaO) bonded to and reacted with vermiculite, a low-cost expanded silicate carrier. The sorbents possess some very unique and desirable properties. These properties include a higher-than-normal affinity for sulfur and nitrogen oxides in stack gases, excellent SO{sub 2}-removal efficiencies and attractive utilization rates at common stack gas temperatures, and the ability to be regenerated. The materials typically remove 99 percent of the SO{sub 2} and a significant percentage of the NO{sub x} in flue gases with high sorbent utilizations. Specific objectives of the project were to evaluate the performance of different continuous methods of employing the new sorbent materials in removing SO{sub 2} and NO{sub x} from a power plant flue gas, to examine the regeneration of one particularly promising sorbent composition: 45 wt % MgO-55 wt % Vermiculite, and to develop a sorption-regeneration system and cost estimates based on this material. The objectives were met in the project. The cost of the 15-month project was $229,717, of which OCDO provided $149,972 and Sanitech provided the remainder. In additions Sanitech and Ohio Edison made significant in-kind contributions to the project, in the form of existing facilities and equipment. The results of this project should help move the new technology forward toward commercialization. Required now are scale-ups of the new technology at more meaningful sizes.

  11. The importance of SO{sub 2} and SO{sub 3} for sulphation of gaseous KCl - An experimental investigation in a biomass fired CFB boiler

    SciTech Connect

    Kassman, Haakan; Baefver, Linda; Aamand, Lars-Erik

    2010-09-15

    This paper is based on results obtained during co-combustion of wood pellets and straw in a 12 MW circulating fluidised bed (CFB) boiler. Elemental sulphur (S) and ammonium sulphate ((NH{sub 4}){sub 2}SO{sub 4}) were used as additives to convert the alkali chlorides (mainly KCl) to less corrosive alkali sulphates. Their performance was then evaluated using several measurement tools including, IACM (on-line measurements of gaseous alkali chlorides), a low-pressure impactor (particle size distribution and chemical composition of extracted fly ash particles), and deposit probes (chemical composition in deposits collected). The importance of the presence of either SO{sub 2} or SO{sub 3} for gas phase sulphation of KCl is also discussed. Ammonium sulphate performed significantly better than elemental sulphur. A more efficient sulphation of gaseous KCl was achieved with (NH{sub 4}){sub 2}SO{sub 4} even when the S/Cl molar ratio was less than half compared to sulphur. Thus the presence of gaseous SO{sub 3} is of greater importance than that of SO{sub 2} for the sulphation of gaseous KCl. (author)

  12. 77 FR 13384 - Additional Guidance on Airfare/Air Tour Price Advertisements; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-06

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF TRANSPORTATION Office of the Secretary Additional Guidance on Airfare/Air Tour Price Advertisements; Correction... Department published a notice entitled ``Additional Guidance on Airfare/Air Tour Price Advertisements,''...

  13. Proof of concept testing of an integrated dry injection system for SO{sub 2}/NO{sub x} control. Final report

    SciTech Connect

    Helfritch, D.J.; Bortz, S.J.; Beittel, R.

    1994-03-01

    The integrated Dry Injection Process (IDIP) consists of combustion modification using low NO{sub x} burners to reduce NO{sub x} emissions, dry injection of hydrated line at economizer temperatures for primary capture of SO{sub 2}, dry injection of a commercial grade sodium bicarbonate at the air heater exit for additional SO{sub 2} and NO{sub x} removal, and humidification for precipitator conditioning. IDIP offers the potential for simultaneously achieving 90% SO{sub 2} removal, and 65% NO{sub x} removal from a high sulfur flue gas. The process is well suited for new or retrofit applications since it can be incorporated within existing economizer and downstream ductwork. Subscale tests were performed in order to identify the best calcium and sodium sorbents. These tests involved the injection of calcium hydroxide and sodium sorbents at various points of the flue gas system downstream of a 0.25 MM BTU/hr. coal fired combustor, and the gas residence times, cooling rates and temperatures were comparable to those found for full-scale utility boilers. These tests verified that a high surface area hydrated lime provides maximum sorbent utilization and identified an alcohol-water hydrated lime as yielding the highest surface area and the best SO{sub 2} removal capability. The tests also identified sodium bicarbonate to be somewhat more effective than sodium sesquicarbonate for SO{sub 2} removal. The proof of concept demonstration was conducted on the large combustor at the Riley Stoker Research Facility in Worcester, MA. When economically compared to conventional limestone slurry scrubbing on a 300 MW plant, the dry injection process shows lower capital cost but higher operating cost. Hydrated lime injection can be less costly than limestone scrubbing when two or more of the following conditions exist: plant is small (less than 100MW); yearly operating hours are small (less than 3000); and the remaining plant lifetime is small (less than 10 years).

  14. Catalytic cartridge SO.sub.3 decomposer

    DOEpatents

    Galloway, Terry R.

    1982-01-01

    A catalytic cartridge internally heated is utilized as a SO.sub.3 decomposer for thermochemical hydrogen production. The cartridge has two embodiments, a cross-flow cartridge and an axial flow cartridge. In the cross-flow cartridge, SO.sub.3 gas is flowed through a chamber and incident normally to a catalyst coated tube extending through the chamber, the catalyst coated tube being internally heated. In the axial-flow cartridge, SO.sub.3 gas is flowed through the annular space between concentric inner and outer cylindrical walls, the inner cylindrical wall being coated by a catalyst and being internally heated. The modular cartridge decomposer provides high thermal efficiency, high conversion efficiency, and increased safety.

  15. Catalytic cartridge SO.sub.3 decomposer

    DOEpatents

    Galloway, Terry R.

    1982-01-01

    A catalytic cartridge surrounding a heat pipe driven by a heat source is utilized as a SO.sub.3 decomposer for thermochemical hydrogen production. The cartridge has two embodiments, a cross-flow cartridge and an axial flow cartridge. In the cross-flow cartridge, SO.sub.3 gas is flowed through a chamber and incident normally to a catalyst coated tube extending through the chamber, the catalyst coated tube surrounding the heat pipe. In the axial-flow cartridge, SO.sub.3 gas is flowed through the annular space between concentric inner and outer cylindrical walls, the inner cylindrical wall being coated by a catalyst and surrounding the heat pipe. The modular cartridge decomposer provides high thermal efficiency, high conversion efficiency, and increased safety.

  16. Catalytic cartridge SO/sub 3/ decomposer

    SciTech Connect

    Galloway, T.R.

    1980-11-18

    A catalytic cartridge surrounding a heat pipe driven by a heat source is utilized as a SO/sub 3/ decomposer for thermochemical hydrogen production. The cartridge has two embodiments, a cross-flow cartridge and an axial flow cartridge. In the cross-flow cartridge, SO/sub 3/ gas is flowed through a chamber and incident normally to a catalyst coated tube extending through the chamber, the catalyst coated tube surrounding the heat pipe. In the axial-flow cartridge, SO/sub 3/ gas is flowed through the annular space between concentric inner and outer cylindrical walls, the inner cylindrical wall being coated by a catalyst and surrounding the heat pipe. The modular cartridge decomposer provides high thermal efficiency, high conversion efficiency, and increased safety. A fusion reactor may be used as the heat source.

  17. Catalytic cartridge SO/sub 3/ decomposer

    SciTech Connect

    Galloway, T.R.

    1982-09-28

    A catalytic cartridge internally heated is utilized as a SO/sub 3/ decomposer for thermochemical hydrogen production. The cartridge has two embodiments, a cross-flow cartridge and an axial flow cartridge. In the cross-flow cartridge, SO/sub 3/ gas is flowed through a chamber and incident normally to a catalyst coated tube extending through the chamber, the catalyst coated tube being internally heated. In the axial-flow cartridge, SO/sub 3/ gas is flowed through the annular space between concentric inner and outer cylindrical walls, the inner cylindrical wall being coated by a catalyst and being internally heated. The modular cartridge decomposer provides high thermal efficiency, high conversion efficiency, and increased safety.

  18. Effects of air pollution on plant-insect interactions: increased susceptibility of greenhouse-grown soybeans to the Mexican bean beetle after plant exposure to SO/sub 2/

    SciTech Connect

    Hughes, P.R.; Potter, J.E.; Weinstein, L.H.

    1982-02-01

    Foliage from greenhouse-grown soybeans fumigated with 524 ..mu..g m/sup -3/ of SO/sub 2/ or from control plants held under the same conditions without fumigation was fed to Mexican bean beetle larvae and adults. The larvae developed faster and grew larger when fed on the fumigated leaves; larval mortality was consistently low and showed no apparent relationship to the type of leaves used as the food source. Adult females showed a significant feeding preference for discs cut from fumigated leaves and were more fecund when fed on the treated foliage than when fed on control leaves. A greater percentage of the females laid eggs, and the viability of the eggs was higher when the females were fed on fumigated leaves. These females produced more eggs per individual, with significant increases in both the number of eggs per mass and the number of masses per female. The longevity of egg-laying females did not differ significantly between the treatments.

  19. Effects of air pollution on plant-insect interactions: increased susceptibility of greenhouse-grown soybeans to the Mexican bean beetle after plant exposure to SO/sub 2/

    SciTech Connect

    Hughes, P.R.; Potter, J.E.; Weinstein, L.H.

    1982-02-15

    Foliage from greenhouse-grown soybeans fumigated with 524 ..mu..g.m/sup -3/ of SO/sub 2/ or from control plants held under the same conditions without fumigation was fed to Mexican bean beetle larvae and adults. The larvae developed faster and grew larger when fed on the fumigated leaves; larva mortality was consistently low and showed no apparent relationship to the type of leaves used as the food source. Adult females showed a significant feeding preference for discs cut from fumigated leaves and were more fecund when fed on the treated foliage than when fed on control leaves. A greater percentage of the females laid eggs, and the viability of the eggs was higher when the females were fed on fumigated leaves. These females produced more eggs per individual, with significant increases in both the number of eggs per mass and the number of masses per female. The longevity of egg-laying females did not differ significantly between the treatments.

  20. Flux of SO/sub 2/ into leaf cells and cellular acidification by SO/sub 2/

    SciTech Connect

    Pfanz, H.; Martinoia, E.; Lange, O.L.; Heber, U.

    1987-12-01

    A comparison of fluxes of SO/sub 2/ from the atmosphere into leaves with fluxes across biomembranes revealed that, apart from the cuticle, the main barrier to SO/sub 2/ entry into leaves are the stomates. SO/sub 2/ fluxes into leaves can be calculated with an accuracy sufficient for many purposes on the assumption that the intracellular SO/sub 2/ concentration is zero. SO/sub 2/ entering green leaf cells is trapped in the cytoplasm. In the light, the products formed in its reaction with water are processed particularly in the chloroplasts. Flux of SO/sub 2/ to the acidic central vacuole of leaf cells is insignificant. Intracellular acidification of barley mesophyll protoplasts by SO/sub 2/ was measured by the uptake of /sup 14/C-labeled 5,5-dimethyl-oxazolidine-2,4-dione. The measured acidification was similar to the acidification calculated from known buffer capacities and the rate of SO/sub 2/ influx when the H/sup +//SO/sub 2/ ratio was assumed to be 2. A comparison of photosynthesis inhibition by SO/sub 2/ with calculated acidification revealed different mechanisms of inhibition at low and at high concentrations of SO/sub 2/. At very low concentrations, inhibition by SO/sub 2/ was even smaller than expected from calculated acidification. The data suggest that, if acidification cannot be compensated by pH-stabilizing cellular mechanisms, it is a main factor of SO/sub 2/ toxicity at low SO/sub 2/ levels. At high levels of SO/sub 2/, anion toxicity and/or radical formation during oxidation of SO/sub 2/ to sulfate may play a large role in inhibition.

  1. High SO{sub 2} removal efficiency testing: PSI Energy`s Gibson Station High SO{sub 2} Removal Efficiency Test Program

    SciTech Connect

    1996-05-20

    A program was conducted at PSI Energy`s Gibson Generating Station to evaluate options for achieving high sulfur dioxide (SO{sub 2}) removal efficiency with the Unit 5 wet limestone flue gas desulfurization (FGD) system. This program was one of six conducted by the U.S. Department of Energy to evaluate low-capital-cost upgrades to existing FGD systems as a means for utilities to comply with the requirements of the 1990 Clean Air Act Amendments (CAAA). The Gibson FGD system employs four absorber modules of the Kellogg/Weir horizontal gas flow design and uses limestone reagent with two additives. Dolomitic lime is added to introduce magnesium to increase liquid-phase alkalinity, and sulfur is added to inhibit sulfite oxidation. The high-efficiency options tested involved using sodium formate or dibasic acid (DBA) as a performance additive, increasing the absorber liquid-to-gas ratio (L/G), and/or increasing the limestone reagent stoichiometry. The unit changed coal sources during the test program. However, the Electric Power Research Institute`s (EPRI) FGD PRocess Integration and Simulation Model (FGDPRISM) was calibrated to the system and used to compare options on a consistent basis. An economic analysis was then done to determine the cost-effectiveness of each high-efficiency option. The results from this program are summarized below.

  2. Water soluble graphene as electrolyte additive in magnesium-air battery system

    NASA Astrophysics Data System (ADS)

    Saminathan, K.; Mayilvel Dinesh, M.; Selvam, M.; Srither, S. R.; Rajendran, V.; Kaler, Karan V. I. S.

    2015-02-01

    Magnesium-air (Mg-air) batteries are an important energy source used to power electronic equipment and automobiles. Metal-air batteries give more energy density due to surplus air involved in reduction reaction at air cathode. In this study, the scope of improvements in the efficiency of Metal-air batteries is investigated through addition of water soluble graphene (WSG) as inhibitor in NaCl electrolyte. The discharge performance, corrosion behaviour and electrochemical impedance are studied for (i) the conventional Mg-air battery using 3.5% NaCl and (ii) Mg-air battery with WSG-based 3.5% NaCl electrolyte. X-ray diffraction analysis for WSG is carried out and it shows the crystalline nature of WSG by an intense sharp peak at 26.3°. Scanning electron microscope study is also performed and shows the flake-like structure of WSG denoted by thin layers of carbon. The immersion of WSG in 3.5% NaCl electrolyte increased the current density from 13.24 to 19.33 mA cm-2. Meanwhile, the WSG-based Mg-air battery was found to hold specific discharge capacity of 1030.71 mAh g-1, which was higher than that obtained in 3.5% NaCl electrolyte (i.e., 822.85 mAh g-1). The WSG-based Mg-air battery shows good self-discharge capacity and higher electrochemical activity during discharge.

  3. TPD study on SO{sub 2} gasification of coal char

    SciTech Connect

    Takarada, T.; Suzuki, Y.

    1996-10-01

    Elementary sulfur can be recovered from SO{sub 2}-containing gas by a gasification reaction between carbon and SO{sub 2}. Gasification of coal chars ranging from brown coal to anthracite was carried out in SO{sub 2} atmosphere using thermo-balance. The gasification temperature ranged from 923 to 1123 K. The SO{sub 2} concentration was 5.3 vol%. Yallourn coal, Australian brown coal, was impregnated with several catalysts. Potassium carbonate, sodium hydroxide, calcium hydroxide, magnesium hydroxide and iron nitrate were used as the starting materials for catalyst impregnation. The active site for SO{sub 2} gasification of coal char was evaluated with TPD technique. The gasification profile was strongly depended on the coal type. High reactivities were observed for low rank coal chars. The gasification rate was enormously enhanced by the addition of alkaline metal catalyst. TPD pattern was depended on the coal type and the catalyst addition. The amount of CO and CO{sub 2} desorbed during TPD procedure in fairly correlated to the reaction rate of sample.

  4. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  5. Metal-air cell comprising an electrolyte with a room temperature ionic liquid and hygroscopic additive

    DOEpatents

    Friesen, Cody A.; Krishnan, Ramkumar; Tang, Toni; Wolfe, Derek

    2014-08-19

    An electrochemical cell comprising an electrolyte comprising water and a hydrophobic ionic liquid comprising positive ions and negative ions. The electrochemical cell also includes an air electrode configured to absorb and reduce oxygen. A hydrophilic or hygroscopic additive modulates the hydrophobicity of the ionic liquid to maintain a concentration of the water in the electrolyte is between 0.001 mol % and 25 mol %.

  6. Predicting the effects of nanoscale cerium additives in diesel fuel on regional-scale air quality.

    PubMed

    Erdakos, Garnet B; Bhave, Prakash V; Pouliot, George A; Simon, Heather; Mathur, Rohit

    2014-11-04

    Diesel vehicles are a major source of air pollutant emissions. Fuel additives containing nanoparticulate cerium (nCe) are currently being used in some diesel vehicles to improve fuel efficiency. These fuel additives also reduce fine particulate matter (PM2.5) emissions and alter the emissions of carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbon (HC) species, including several hazardous air pollutants (HAPs). To predict their net effect on regional air quality, we review the emissions literature and develop a multipollutant inventory for a hypothetical scenario in which nCe additives are used in all on-road and nonroad diesel vehicles. We apply the Community Multiscale Air Quality (CMAQ) model to a domain covering the eastern U.S. for a summer and a winter period. Model calculations suggest modest decreases of average PM2.5 concentrations and relatively larger decreases in particulate elemental carbon. The nCe additives also have an effect on 8 h maximum ozone in summer. Variable effects on HAPs are predicted. The total U.S. emissions of fine-particulate cerium are estimated to increase 25-fold and result in elevated levels of airborne cerium (up to 22 ng/m3), which might adversely impact human health and the environment.

  7. SO{sub 2} removal by reagents prepared from lime and recycled glass

    SciTech Connect

    Arthur, L.F.; Rochelle, G.T.

    1995-06-01

    High surface area solids that are reactive toward SO{sub 2} have been produced from recycled post-consumer glass and lime. Experimental results show that the rate of surface area formation is directly proportional to the initial surface area of the glass. Gypsum is shown to be an effective additive for reactions at 92{degrees}C to increase surface area after long times. For slurry reactions with gypsum, increasing the slurry temperature to 120{degrees}C produced a product with higher surface area than that produced at 92{degrees}C only for reaction times <15 hours. Absorption of SO{sub 2} with solids made from recycled glass yield 80% utilization of available alkalinity when reacted with 1000-2000 ppm SO{sub 2} at 35{degrees}C and 64% relative humidity. The alkalinity was from both the lime ({approximately}86%) and the glass ({approximately}14%).

  8. Direct observation of reversible and irreversible stomatal responses of attached sunflower leaves to SO/sub 2/

    SciTech Connect

    Omasa, K.; Hashimoto, Y.; Kramer, P.J.; Strain, B.R.; Aiga, I.; Kondo, J.

    1985-09-01

    The effects of SO/sub 2/ on stomatal aperture of attached sunflower leaves were observed with a remote-control light microscope system that permitted continuous observation of stomatal responses over periods of several hours. The relationship between actual stomatal aperture and stomatal conductance, measured with a porometer, also was examined on leaves before and after exposure to SO/sub 2/. A distinction between uninjured and injured regions was clearly visible on leaves after exposure to 1.5 microliters per liter SO/sub 2/ for less than an hour. During the exposure, the mean value of apertures for many stomata, which indicates stomatal conductance and transpiration rate, tended to decrease simultaneously in the uninjured and injured regions. There was a good correlation between pore width and stomatal conductance measured with a porometer before exposure to SO/sub 2/. This correlation continued in leaves exposed to SO/sub 2/ until visible, irreversible injury occurred, but then it disappeared. The results of these experiments indicate the necessity of continuous observation of individual stomata under the microscope to understand the effects of air pollutants such as SO/sub 2/ on stomatal behavior.

  9. Gaseous deposition to snow 2. Physical-chemical model for SO/sub 2/ deposition

    SciTech Connect

    Bales, R.C.; Valdez, M.P.; Dawson, G.A.

    1987-08-20

    A diffusion/reaction model of SO/sub 2/ uptake by snow containing liquid water is used to examine the snowpack processes controlling accumulation of dissolved S(IV) and S(VI). Surface deposition velocity v/sub d/ (defined as overall accumulation rate divided by surface SO/sub 2/ concentration) depends on the amount of liquid water in the snow, the time scale considered, the rate of S(IV) to S(VI) conversion in the aqueous phase, and the SO/sub 2/ concentration. In the absence of any oxidation, v/sub d/ for dense snow (specific gravity 0.4) with a moderate liquid water mass fraction (X/sub m/ = 0.01) and SO/sub 2/ concentration of 20 ppbv (parts per billion by volume) is calculated to be 0.026 cm s/sup -1/ after 6 hours. Deposition velocity increases by a factor of 3.2 for each tenfold increase in X/sub m/ and by a factor of 2.5--3.2 for each tenfold decrease in time. SO/sub 2/ penetration into the snowpack is about 5 cm for the 6--hour case. In the presence of air containing 30 ppbv ozone and otherwise identical conditions, 80% of the accumulated sulfur is as S(VI), and the calculated v/sub d/ is 0.036 cm s/sup -1/. A further tenfold increase in ozone concentration gives only a 70% increase in v/sub d/. A similar dependence is calculated for oxygen (catalyzed by Fe(III)) as oxidant, but that for hydrogen peroxide is much stronger and almost linear. A tenfold increase in SO/sub 2/ concentration (with ozone at 30 ppb) results in a 2.3-fold decrease in v/sub d/. Wet snow with a liquid water mass fraction of about 0.1 gives a deposition velocity at 20 ppb SO/sub 2/ of 0.12 cm s/sup -1/, with a penetration of only 2 cm. Calculated and observed uptakes of SO/sub 2/ by snow are in good agreement. copyrightAmerican Geophysical Union 1987

  10. Chemical behavior of SO/sub 3//sup -/ and SO/sub 5//sup -/ radicals in aqueous solutions. [Pulsed irradiation

    SciTech Connect

    Huie, R.E.; Neta, P.

    1984-11-08

    The chemistry of the radicals SO/sub 3//sup -/ and SO/sub 5//sup -/ has been investigated by using pulse radiolysis with kinetic spectrophotometry. Rate constants for the oxidation by SO/sub 3//sup -/ of a variety of organic compounds were measured and equilibrium constants determined for the reactions of SO/sub 3//sup -/ with chlorpromazine and phenol. SO/sub 3//sup -/ was found to be a mild oxidant with a redox potential of E(SO/sub 3//sup -//SO/sub 3//sup 2 -/) = 0.63 V (vs. NHE) at pH > 7 and E(SO/sub 3//sup -//HSO/sub 3//sup -/) = 0.84 V at pH 3.6. The reaction of SO/sub 3//sup -/ with O/sub 2/ was shown to produce SO/sub 5//sup -/. The oxidation of several compounds by SO/sub 5//sup -/ was found to occur more rapidly than their oxidation by SO/sub 3//sup -/. E(SO/sub 5//sup -//HSO/sub 5//sup -/) was estimated to be approximately 1.1 V at pH 7. 44 references, 2 figures, 2 tables.

  11. Sorption of SO/sub 2/ on metal oxides in a fluidized bed

    SciTech Connect

    Uysal, B.Z.; Aksahin, I.; Yucel, H.

    1988-03-01

    A preliminary experimental study is described in which a low concentration of SO/sub 2/ (0.2% v/v) is removed from air at temperatures between 358 and 640 K by reaction with bauxite and red mud, which consists of several metal oxides in a lab-size fluidized bed reactor of 5-cm diameter. CuO on activated alumina, a well-known sorbent for SO/sub 2/, was also tested in the same system for comparison. A model based on the two-phase theory of fluidization was used to simulate the sorption process. It was shown that a kinetic rate expression for sorption of SO/sub 2/ on a single metal oxide to yield a metal sulfate can also be used for mixtures of metal oxides by defining an overall apparent rate coefficient and an overall consumption coefficient for active sites. The work identified that bauxite and red mud could also be considered as potential sorbents like CuO for SO/sub 2/ sorption in a typical range of stack gas temperatures.

  12. Gas-phase oxidation of SO/sub 2/ in the ozone-olefin reactions

    SciTech Connect

    Hatakeyama, S.; Kobayashi, H.; Akimoto, H.

    1984-09-27

    Gas-phase oxidation of SO/sub 2/ in the ozone-olefin reactions was studied, and the yield of sulfuric acid aerosol was determined for various types of olefins under atmospheric pressure. No sulfur-containing compounds other than sulfuric acid was detected. Pressure dependence of the yield of H/sub 2/SO/sub 4/ was studied for the first time for trans-2-butene. The yield decreased to zero as the total pressure of air was decreased. This fact supports the contention that only a stabilized Criegee intermediate can undergo bimolecular reactions. Stabilized fractions of CH/sub 2/O0 and CH/sub 3/CHOO in the ozone reaction of ethylene and trans-2-butene under atmospheric pressure are 0.390 +/- 0.053 and 0.185 +/- 0.028, respectively. The yield of H/sub 2/SO/sub 4/ was as low as 0.052 +/- 0.013, 0.032 +/- 0.024, and 0.029 +/- 0.015 for cyclopentane, cyclohexene, and cycloheptene, respectively. The yield of H/sub 2/SO/sub 4/ for ..cap alpha..- and ..beta..-pinene was 0.125 +/- 0.040 and 0.249 +/- 0.024, respectively. The rate constant ratio of decomposition of the initially formed hot Criegee intermediate to its collisional stabilization was obtained to be (3.9 +/- 0.8) x 10/sup 18/ molecules/cm/sup 3/ for trans-2-butene.

  13. Novel electrochemical behavior of zinc anodes in zinc/air batteries in the presence of additives

    NASA Astrophysics Data System (ADS)

    Lee, Chang Woo; Sathiyanarayanan, K.; Eom, Seung Wook; Kim, Hyun Soo; Yun, Mun Soo

    In our continued efforts to find an electrically rechargeable zn/air secondary battery, we report the unique behavior of a zinc oxide anode in the presence of additives such as phosphoric acid, tartaric acid, succinic acid and citric acid. These additives were added to the electrolyte, which is an 8.5 M KOH solution containing 25 g of ZnO and 3000 ppm of polyethylene glycol in 1 l of water. In zn/air systems there are two main problems namely the hydrogen overpotential and dendrite formation during recharging. Investigations have studied in detail both of the problems in order to overcome them. The results obtained in presence of additives are compared with the behavior of the electrolyte 8.5 M KOH in the absence of additives. It has been concluded that the hydrogen overpotential is raised enormously while dendrite formation is reduced to some extent. Out of the four acids studied, the order of increase in hydrogen overpotential is: tartaric acid > succinic acid > phosphoric acid > citric acid. The prevention of dendrite formation follows the order: citric acid > succinic acid > tartaric acid > phosphoric acid.

  14. Additive-free harvesting of oleaginous phagotrophic microalga by oil and air flotation.

    PubMed

    Hosseini, Majid; Starvaggi, Haley A; Ju, Lu-Kwang

    2016-07-01

    A unique oleaginous phagotrophic microalga Ochromonas danica is poised for effective lipid production from waste. Cell harvesting and dewatering are major costs in making algae-based products. In this work an effective additive-free harvesting method was developed, taking advantage of O. danica's comparatively more hydrophobic surface and larger size. The algal cells' partitioning to oil/water interface was evaluated. Recovery by flotation with waste cooking oil was optimized using an L-9 Taguchi orthogonal-array design. Further, additive-free cell collection and concentrating by air flotation was studied for the effects of both physical factors (column dimension, air-stone pore size, sample-to-column volume ratio) and culture properties (pH, culture growth stage, cell concentration, and pure versus impure cultures). The optimized process consistently achieved >90 % recovery in a single stage. 98+ % recovery could be achieved when starting concentrations were >10(8) cells/ml, or potentially using a two- or multi-stage process for diluter cultures.

  15. Combined SO{sub 2}/NO{sub x} reduction technology

    SciTech Connect

    Livengood, C.D.; Huang, H.S.; Markussen, J.M.

    1992-09-01

    Enactment of the Clean Air Act Amendments and passage of state legislation leading to more stringent nitrogen oxides (NO{sub x}) regulations have fueled research and development efforts on technologies for the combined control of sulfur dioxide (SO{sub 2}) and NO{sub x}. The integrated removal of both SO{sub 2} and NO{sub x}, in a single system can offer significant advantages over the use of several separate processes, including such factors as reduced system complexity, better operability, and lower costs. This paper reviews the status of a number of integrated flue-gas-cleanup (FGC) systems that have reached a significant stage of development, focusing on post-combustion processes that have been tested or are ready for testing at the pilot scale or larger. A brief process description, a summary of the development status and performance achieved to date, pending commercialization issues, and process economics (when available) are given for each technology.

  16. Is it time to rethink SO{sub 2} control technology selection?

    SciTech Connect

    Dickerman, J.; Swell, M.

    2007-11-15

    The article traces the history of flue gas desulfurization (FGD) systems in power plants in the USA following the 1990 Clean Air Act which divided boilers into Phase I (larger SO{sub 2} emitters) and Phase II units. The Clean Air Interstate Rule (CAIR) will soon require emission control on smaller boilers burning low and medium-sulfur coal. Today the systems of choice are dry FGD systems for low sulfur coals and greater than wet LSFO. (limestone forced oxidation systems) for coal with sulfur content about 2%. Demand for wet FGD coupled with tighter regulations has led to significant cost increases in LSFO. technology. 4 refs., 2 figs.

  17. Improved performance of air-cathode microbial fuel cell through additional Tween 80

    NASA Astrophysics Data System (ADS)

    Wen, Qing; Kong, Fanying; Ma, Fang; Ren, Yueming; Pan, Zhongcheng

    The ability of electron transfer from microbe cell to anode electrode plays a key role in microbial fuel cell (MFC). This study explores a new approach to improve the MFC performance and electron transfer rate through addition of Tween 80. Results demonstrate that, for an air-cathode MFC operating on 1 g L -1 glucose, when the addition of Tween 80 increases from 0 to 80 mg L -1, the maximum power density increases from 21.5 to 187 W m -3 (0.6-5.2 W m -2), the corresponding current density increases from 1.8 to 17 A m -2, and the resistance of MFC decreases from 27.0 to 5.7 Ω. Electrochemical impedance spectroscopy (EIS) analysis suggests that the improvement of overall performance of the MFC can be attributed to the addition of Tween 80. The high power density achieved here may be due to the increase of permeability of cell membranes by addition of Tween 80, which reduces the electron transfer resistance through the cell membrane and increases the electron transfer rate and number, consequently enhances the current and power output. A promising way of utilizing surfactant to improve energy generation of MFC is demonstrated.

  18. Assessment of horizontal laminar air flow instrument table for additional ultraclean space during surgery.

    PubMed

    Nilsson, K-G; Lundholm, R; Friberg, S

    2010-11-01

    The area in a vertical ultraclean laminar air flow (LAF) theatre is usually too small to accommodate all the equipment needed for major surgery. We investigated the addition of an instrument table supplied with fixed ultraclean LAF and placed alongside the existing main LAF unit, to determine its physical and bacteriological effect on the main unit. In phase 1, with two investigators but without a patient, smoke tests showed no intrusion of air from the table into the main unit and particle counts did not show any adverse effect on the main LAF unit. In phase 2, during patients undergoing two total knee replacements, the LAF table and a table without LAF were placed alongside the main LAF unit. The tables were subjected to the activity of an extra operating room (OR) nurse working from inside the main LAF vigorously simulating handling of instruments. During this activity, the >5μm particle counts were 275/m(3) at the instrument table with LAF and 8550/m(3) at the table without LAF (P<0.0001). Also, without the OR nurse activity, the particle counts, just inside the main unit and adjacent to the LAF table, were significantly reduced (P<0.03-0.003). Sedimentation plates on the LAF table and in the main unit registered 22 and 25cfu/m(2)/h respectively compared with 45cfu/m(2)/h at the instrument table without LAF. In conclusion, the results from the smoke tests, particle counts and bacteriological evaluation showed that the additional instrument table supplied with LAF is efficient and can be safely used as an extension additional to a main OR LAF unit.

  19. SO{sub 3} effect on mercury control

    SciTech Connect

    Jarvis, J.; Meserole, F.

    2008-01-15

    Utilities are counting on their flue gas desulfurization (FGD) scrubbers and selective catalytic reduction (SCR) systems to control mercury as well as pollutants such as SO{sub 2} and NOx. As more stringent emission limits are phased in, utilities will likely need supplemental measures such as activated carbon injection (ACI) to further reduce emissions. However, SO{sub 3} could foul this strategy and potentially jeopardize the ability of some coal-fired power plants to meet future mercury emission limits. A growing consensus exists among emissions control engineers and researchers that the presence of SO{sub 3} in the flue gas from coal-fired boilers reduces the capacity of fly ash and/or activated carbon to adsorb gaseous mercury species. The impact of SO{sub 3}, which is actually a combination of SO{sub 3} and H{sub 2}SO{sub 4} vapor, has been investigated on a fundamental level using approaches such as fixed-bed reactors and activated carbons. Pilot testing has provided mercury removal efficiency data on actual flue gas over a wide range of SO{sub 3} concentrations. If SO{sub 3} threatens the feasibility of low capital-cost approaches involving activated carbon, utilities will be forced to explore other more costly options. One example is the use of mercury catalytic oxidation to boost mercury removal efficiencies in wet scrubbers. However, catalytic oxidation of mercury using SCR catalysts may have unintended consequences. A better alternative may be to remove the SO{sub 3} so it does not interfere with the removal of mercury via the fly ash and/or activated carbon for example using sodium sorbents. The article outlines research projects on alternatives. 4 figs.

  20. Influence of propane additives on the detonation characteristics of H2-air mixtures

    NASA Astrophysics Data System (ADS)

    Cheng, Guanbing; Bauer, Pascal; Zitoun, Ratiba

    2014-03-01

    Hydrogen is more and more considered as a potential fuel for propulsion applications. However, due to its low ignition energy and wide flammability limits, H2-air mixtures raise a concern in terms of safety. This aspect can be partly solved by adding an alkane to these mixtures, which plays the role of an inhibitor. The present paper provides data on such binary fuel-air mixtures where various amounts of propane are added to hydrogen. The behavior of the corresponding mixtures, in terms of detonation characteristics and other fundamental properties, such as the cell size of the detonation front and induction delay, are presented and discussed for a series of equivalence ratios and propane addition. The experimental detonation velocity is in good agreement with calculated theoretical Chapman-Jouguet values. Based on soot tracks records, the cell size λ is measured, whereas the induction length L i is derived from data using a GRI-Mech kinetic mechanism. These data allow providing a value of the coefficient K = λ/L i .

  1. Separating Octadecyltrimethoxysilane Hydrolysis and Condensation at the Air/Water Interface through Addition of Methyl Stearate

    PubMed Central

    Britt, David W.; Hlady, Vladimir

    2012-01-01

    The hydrolysis and condensation of octadecyltrimethoxysilane (OTMS) at the air/water interface were monitored through molecular area changes at a constant surface pressure of 10 mN/m. The onset of condensation was delayed through the addition of methyl stearate (SME) acting as an inert filler molecule. In the absence of SME, complete gelation of OTMS required 30 h, during which time OTMS condensation occurred concomitantly with hydrolysis. In the presence of SME, the OTMS monolayer gelation rate increased in proportion to the amount of SME present. A 1:6 OTMS:SME molar ratio resulted in monolayer gelation within 30 min, suggesting completion of monomer hydrolysis prior to condensation. These findings indicate that lability of OTMS to hydrolysis at the air/water interface is governed by steric and conformational constraints at the silicon atom site, with monomeric OTMS being much more reactive than oligomeric OTMS. Fluorescence microscope images demonstrated that the OTMS condensed domain size also decreased with increasing SME concentrations, further implicating SME’s role as an inert filler. PMID:25132807

  2. Advanced in-duct sorbent injection for SO{sub 2} control. Final technical report

    SciTech Connect

    Stouffer, M.R.; Withium, J.A.; Rosenhoover, W.A.; Maskew, J.T.

    1994-12-01

    The objective of this research project was to develop a second generation duct sorbent injection technology as a cost-effective compliance option for the 1990 Clean Air Act Amendments. Research and development work was focused on the Advanced Coolside process, which showed the potential for exceeding the original performance targets of 90% SO{sub 2} removal and 60% sorbent utilization. Process development was conducted in a 1000 acfm pilot plant. The pilot plant testing showed that the Advanced Coolside process can achieve 90% SO{sub 2} removal at sorbent utilizations up to 75%. The testing also showed that the process has the potential to achieve very high removal efficiency (90 to >99%). By conducting conceptual process design and economic evaluations periodically during the project, development work was focused on process design improvements which substantially lowered process capital and operating costs, A final process economic study projects capital costs less than one half of those for limestone forced oxidation wet FGD. Projected total SO{sub 2} control cost is about 25% lower than wet FGD for a 260 MWe plant burning a 2.5% sulfur coal. A waste management study showed the acceptability of landfill disposal; it also identified a potential avenue for by-product utilization which should be further investigated. Based on the pilot plant performance and on the above economic projections, future work to scale up the Advanced Coolside process is recommended.

  3. Historical analysis of SO{sub 2} pollution control policies in China

    SciTech Connect

    Gao, C.L.; Yin, H.Q.; Ai, N.S.; Huang, Z.W.

    2009-03-15

    Coal is not only an important energy source in China but also a major source of air pollution. Because of this, China's national sulfur dioxide (SO{sub 2}) emissions have been the highest in the world for many years, and since the 1990s, the territory of China's south and southwest has become the third largest acid-rain-prone region in the world. In order to control SO{sub 2} emissions, the Chinese government has formulated and promulgated a series of policies and regulations, but it faces great difficulties in putting them into practice. In this retrospective look at the history of SO{sub 2} control in China, we found that Chinese SO{sub 2} control policies have become increasingly strict and rigid. We also found that the environmental policies and regulations are more effective when central officials consistently give environmental protection top priority. Achieving China's environmental goals, however, has been made difficult by China's economic growth. Part of this is due to the practice of environmental protection appearing in the form of an ideological 'campaign' or 'storm' that lacks effective economic measures. More recently, better enforcement of environmental laws and regulations has been achieved by adding environmental quality to the performance assessment metrics for leaders at all levels. To continue making advances, China needs to reinforce the economic and environmental assessments for pollution control projects and work harder to integrate economic measures into environmental protection. Nonetheless, China has a long way to go before economic growth and environmental protection are balanced.

  4. Elastic Properties and Structural Studies on Boro-Vanadate Glasses Containing Sulphate (SO{sub 4}{sup 2-}) Ions

    SciTech Connect

    Reddy, M. Sudhakar; Gowda, V. C. Veeranna; Reddy, C. Narayana

    2011-12-12

    Elastic properties of xLi{sub 2}SO{sub 4}-16 Li{sub 2}O-(84-x) [0.7 B{sub 2}O{sub 3}-0.3 V{sub 2}O{sub 5}] where (5{<=}x{>=}30) glasses have been prepared by melt quenching method and structural investigations were carried out using ultrasonic pulse echo overlap technique at a frequency of 10 MHz and at 300 K. The molar volume increases and the density decreases with the increase of Li{sub 2}SO{sub 4} concentration due to the incorporation of SO{sub 4}{sup 2-} ions into the modified macromolecular network. The addition of Li{sub 2}SO{sub 4} content leads to loose packing structure which is attributed to volume increasing effect and the reduction in the vibrations of borate and vanadate lattices. Increase in Li{sub 2}{sup SO}{sub 4} results in decreasing cross link density which in turn decreases elastic moduli. The results are discussed in view of its network structure. The structural groups [VOO{sub 3/2}]{sup 0} and [BO{sub 3/2}]{sup 0} modify preferentially. This preference in modification is decided by the electronegativity ({chi}) of the structural groups.

  5. Simultaneous removal of SO{sub 2}, NOx, and Hg from coal flue gas using a NaClO{sub 2}-enhanced wet scrubber

    SciTech Connect

    Hutson, N.D.; Krzyzynska, R.; Srivastava, R.K.

    2008-08-15

    A bench-scale study was conducted on the simultaneous removal Of SO{sub 2}, NOx, and mercury (both Hg{sup 0} and Hg{sup 2+}) from a simulated coal flue gas using a wet calcium carbonate scrubber. The multipollutant capacity of the scrubber was enhanced with the addition of the oxidizing salt, sodium chlorite. The results showed a maximum scrubbing of 100% for SO{sub 2} and Hg species and near complete NO oxidation with about 60% scrubbing of the resulting NOx species. The chlorite additive was less effective as an oxidant in the absence of SO{sub 2} and NO in the flue gas. Oxidation of NO and mercury were only about 50% and 80%, respectively, in the case of no SO{sub 2} in the simulated flue gas. The mercury oxidation was similarly affected by the absence of NO in the flue gas.

  6. Suppression of methane/air explosion by ultrafine water mist containing sodium chloride additive.

    PubMed

    Cao, Xingyan; Ren, Jingjie; Zhou, Yihui; Wang, Qiuju; Gao, Xuliang; Bi, Mingshu

    2015-03-21

    The suppression effect of ultrafine mists on methane/air explosions with methane concentrations of 6.5%, 8%, 9.5%, 11%, and 13.5% were experimentally studied in a closed visual vessel. Ultrafine water/NaCl solution mist as well as pure water mist was adopted and the droplet sizes of mists were measured by phase doppler particle analyzer (PDPA). A high speed camera was used to record the flame evolution processes. In contrast to pure water mist, the flame propagation speed, the maximum explosion overpressure (ΔP(max)), and the maximum pressure rising rate ((dP/dt)max) decreased significantly, with the "tulip" flame disappearing and the flame getting brighter. The results show that the suppressing effect on methane explosion by ultrafine water/NaCl solution mist is influenced by the mist amount and methane concentration. With the increase of the mist amount, the pressure, and the flame speed both descended significantly. And when the mist amount reached 74.08 g/m(3) and 37.04 g/m(3), the flames of 6.5% and 13.5% methane explosions can be absolutely suppressed, respectively. All of results indicate that addition of NaCl can improve the suppression effect of ultrafine pure water mist on the methane explosions, and the suppression effect is considered due to the combination effect of physical and chemical inhibitions.

  7. Predicting the Effects of Nano-Scale Cerium Additives in Diesel Fuel on Regional-Scale Air Quality

    EPA Science Inventory

    Diesel vehicles are a major source of air pollutant emissions. Fuel additives containing nanoparticulate cerium (nCe) are currently being used in some diesel vehicles to improve fuel efficiency. These fuel additives also reduce fine particulate matter (PM2.5) emissio...

  8. 40 CFR 49.5 - Tribal requests for additional Clean Air Act provisions for which it is not appropriate to treat...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... TRIBAL CLEAN AIR ACT AUTHORITY Tribal Authority § 49.5 Tribal requests for additional Clean Air Act... request that the Administrator specify additional provisions of the Clean Air Act for which it would be... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Tribal requests for additional...

  9. Predictive models of circulating fluidized bed combustors: SO[sub 2] sorption in the CFB loop

    SciTech Connect

    Gidaspow, D.; Therdthianwong, A. . Dept. of Chemical Engineering)

    1993-02-01

    The overall objective of this investigation is to develop experimentally verified models for circulating fluidized bed (CFB) combustors. Sorption of S0[sub 2] with calcined limestone was studied in a PYROFLOW type CFB loop at conditions approximating those found in a CFB combustor. Initially the CFB loop contained 150 micron CaO particles of a density of 3.3 g/cm[sup 3] and air at 1143[degrees]K and 3.25 atm. Atzero time, air containing 600 ppm SO[sub 2], was introduced into the riser bottom at 1143[degrees]K. The effect of gas velocity, sorbent inventory and inlet pressure on the sorption of SO[sub 2], were studied isothermally by running our hydrodynamic code with the S0[sub 2] sorption conservation of species equation. At a velocity of 5m/sec., reported to be a typical velocity by PYROPOWER, there is reasonably good S0[sub 2] removal. At 10 m/sec the S0[sub 2] removal is poor. The best SO[sub 2], removal is for a velocity of 5 m/s and a high bed inventory, initial bed height, H = 9m. Most of the S0[sub 2] is removed in the first two meters of the reactor. However, the S0[sub 2] removal is not complete at the bed outlet. This is due to mixing. At the left wall of the reactor (wall opposite the solids inlet) the S0[sub 2] removal was poor due to gas bypassing caused by the asymmetrical solids inlet. Simulation of the PYROPOWER loop with a symmetrical inlet gave us an order of magnitude improvement over the conventional PYROPOWER system. These results demonstrate the practical utility of the predictive model that we have developed over the last three years.

  10. Additional Actions Can Improve Naval Air Systems Command’s Use of Undefinitized Contractual Actions

    DTIC Science & Technology

    2011-06-08

    Naval Air Systems Command NTE Not-to-Exceed UCA Undefinitized Contractual Action U.S.C. United States Code INSPECTOR GENERAL DEPARTMENT...States Code . We reviewed 52 UCAs with a total not-to-exceed value of about $1.6 billion awarded by the Naval Air Systems Command (NAVAIR) from FY...2004 through FY 2009 to determine whether NAVAIR personnel complied with the restrictions of the United States Code and whether they appropriately

  11. Catalytic-cartridge SO/sub 3/ decomposer

    SciTech Connect

    Galloway, T.R.

    1981-05-22

    A catalytic cartridge internally heated is utilized as a SO/sub 3/ decomposer for thermochemical hydrogen production. The cartridge has two embodiments, a cross-flow cartridge and an axial flow cartridge. In the cross-flow cartridge, SO/sub 3/ gas is flowed through a chamber and incident normally to a catalyst coated tube extending through the chamber, the catalyst coated tube being internally heated. In the axial-flow cartridge, SO/sub 3/ gas is flowed through the annular space between concentric inner and outer cylindrical walls, the inner cylindrical wall being coated by a catalyst and being internally heated. The modular cartridge decomposer provides high thermal efficiency, high conversion efficiency, and increased safety.

  12. Oxidation of SO[sub 2] to SO[sub 3] over honeycomb DeNoxing catalysts

    SciTech Connect

    Svachula, J.; Alemany, L.J.; Ferlazzo, N.; Forzatti, P.; Tronconi, E. ); Bregani, F. )

    1993-05-01

    A systematic study addressing the effects of the operating conditions (contact time, temperature), of feed composition (O[sub 2], SO[sub 2], H[sub 2]O, NH[sub 3], NO[sub x], NH[sub 3] + NO[sub x] concentrations), and of catalyst design parameters (wall thickness, V content) in the oxidation of SO[sub 2] to SO[sub 3] over honeycomb commercial-type DeNoxing catalysts is described. Data are presented which refer to transient behavior of the catalysts, indicating that long conditioning times are required associated with the buildup of surface sulfate species. The steady-state reaction rate is of variable order in SO[sub 2], the order increasing with SO[sub 2] concentration as long as this is below 200 ppm and then decreasing; it is asymptotically independent of oxygen, depressed by water, strongly inhibited by ammonia, and slightly enhanced by NO[sub x]. The apparent activation energy changes from [approximately]50 to [approximately]20 kcal/mol on increasing the reaction temperature. A redox steady-state kinetic model is presented which accommodates qualitatively all of the observed effects. Once properly modified the same model has the potential to explain also transient effects during conditioning of the catalyst.

  13. Cl2 Measurements in Polluted Coastal Air Using a Br- Addition CIMS Technique

    NASA Astrophysics Data System (ADS)

    Lawler, M. J.; Saltzman, E. S.

    2008-12-01

    Molecular chlorine (Cl2) was measured in ambient air using chemical ionization mass spectrometry (CIMS) with Br- as a reagent ion. Ionization was carried out by adding CHBr3 to ambient air and flowing the gas mixture through a 63Ni ion source maintained at 300 Torr. The resulting Cl2Br- adduct was collisionally dissociated in a triple quadrupole mass spectrometer and detected as Cl-. Ambient Cl2 measurements were made at Irvine, CA, from August 1-8, 2008. Air was drawn to the instrument from outside via a ~4m long laminar flow inlet. Inlet and instrument blanks were assessed by passing ambient air through carbonate-coated glass wool, and the instrument was calibrated with a Cl2 permeation tube. During this study, the mean detection limit for Cl2 was estimated at approximately 2 ppt. Cl2 showed a diel cycle on the days it was detectable, with nighttime mixing ratios up to about 15 ppt and daytime values of a few ppt or less. A rapid decrease in Cl2 in surface air was observed overnight in association with stagnation of the nocturnal surface layer.

  14. Acid rain program emissions scorecard 1997. SO[sub 2], NO[sub x], heat input, and CO[sub 2] emission trends in the electric utility industry

    SciTech Connect

    Not Available

    1999-01-01

    Established under Title IV of the Clean Air Act Amendments of 1990, the Acid Rain Program requires the electric utility industry to reduce emissions of sulfur dioxide (SO[sub 2]) and nitrogen oxides (NO[sub x]), the pollutants that cause acid rain. To ensure that the desired emission reductions are achieved, the program implements an innovative market-based regulatory approach with utilities having flexible compliance options. After each calendar year, EPA determines the compliance of each facility relating to its SO[sub 2] and NO[sub x] emissions requirements and publishes a report documenting the results.

  15. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  16. Results of SO{sub 2}, NO{sub x}, and CO monitoring at McMurdo Station, Antarctica

    SciTech Connect

    Lugar, R.M.

    1993-05-01

    This report presents the results of ambient air monitoring of carbon monoxide (CO), sulfur dioxide (SO{sub 2}), nitric oxide (NO), nitrogen dioxide (NO{sub 2}), and total oxides of nitrogen (NO{sub x}) performed during the final weeks of the 1992-1993 austral summer in the vicinity of McMurdo Station, Antarctica. Commercially available, high sensitivity ambient air gas analyzers were used to continuously measure gas concentrations at two locations over a two and a three week time period respectively. Sampling site selection, sampling procedures and quality assurance procedures used for this effort were consistent with U.S. Environmental Protection Agency guidelines for local ambient air quality networks. CO, SO{sub 2}, and NO{sub 2} concentrations measured were below the associated U.S. National Ambient Air Quality Standards. Carbon monoxide levels measured at both locations were near or below the instrument detection limit of 0.1 part per million (ppm). Hourly average SO{sub 2} concentrations ranged from below the detection limit of 1 part per billion (ppb) to a single maximum hourly average value of 60 ppb. Hourly average NO{sub 2} concentrations ranged from below the detection limit of 1 ppb to a single maximum hourly average value of 26 ppb. The impact on local air quality of ships docked at an ice pier was observed and quantified. The initial baseline effort demonstrated that site selection and sampling equipment performance were satisfactory, and provided useful data for assessing the impact of McMurdo operations on the local ambient air quality.

  17. Environmental Assessment: Construct a CDC Main Entry Addition at Grand Forks Air Force Base

    DTIC Science & Technology

    2006-03-01

    North Dakota. Purpose and Need: The purpose of the proposed action is to construct an addition to the northeast end of the Child Development Center...families. There is a companion proposal to repair the administrative support area in the northeast end of the Child Development Center (CDC), Bldg...action is to construct an addition to the northeast end of the Child Development Center (CDC), Building 168 at 1683 J St. The addition will provide

  18. Why are allowance prices so low? An analysis of the SO{sub 2} emissions trading program

    SciTech Connect

    Ellerman, A.D.; Montero, J.P.

    1997-12-31

    This paper presents an analysis of the reduction in SO{sub 2} emissions by electric utilities between 1985 and 1993. We find that, as of 1993, emissions had been reduced for reasons largely unrelated to the emission reduction mandate incorporated in Title IV of the 1990 Clean Air Act Amendments. The principal reason appears to be the change in the economics of coal choice that resulted from the remarkable decline in rail rates for low sulfur western coal delivered to higher sulfur coal-fired plants in the Midwest. Consequently, one of the reasons that allowance prices are lower than expected is that less sulfur need be removed to meet the Title IV caps on aggregate SO{sub x} emissions.

  19. Status of flue-gas treatment technologies for combined SO[sub 2]/NO[sub x] reduction

    SciTech Connect

    Livengood, C.D. . Energy Systems Div.); Markussen, J.M. )

    1993-01-01

    Enactment of the Clean Air Act Amendments and passage of state legislation leading to more stringent nitrogen oxides (NO.) regulations have fueled research and development efforts on the technologies for the combined control of sulfur dioxide (SO[sub 2]) and NO[sub x]. The integrated removal of both SO[sub 2] and NO[sub x] in a single system can offer significant advantages over the use of several separate processes, including such factors as reduced system complexity, better operability, and lower costs. This paper reviews the status of a number of integrated flue-gas-cleanup systems that have reached a significant stage of development, focusing on post-combustion processes that have been tested or are ready for testing at the pilot scale or larger. A brief process description, a summary of the development status and performance achieved to date, pending commercialization issues, and process economics (when available) are given for each technology.

  20. On the effect of carbon monoxide addition on soot formation in a laminar ethylene/air coflow diffusion flame

    SciTech Connect

    Guo, Hongsheng; Thomson, Kevin A.; Smallwood, Gregory J.

    2009-06-15

    The effect of carbon monoxide addition on soot formation in an ethylene/air diffusion flame is investigated by experiment and detailed numerical simulation. The paper focuses on the chemical effect of carbon monoxide addition by comparing the results of carbon monoxide and nitrogen diluted flames. Both experiment and simulation show that although overall the addition of carbon monoxide monotonically reduces the formation of soot, the chemical effect promotes the formation of soot in an ethylene/air diffusion flame. The further analysis of the details of the numerical result suggests that the chemical effect of carbon monoxide addition may be caused by the modifications to the flame temperature, soot surface growth and oxidation reactions. Flame temperature increases relative to a nitrogen diluted flame, which results in a higher surface growth rate, when carbon monoxide is added. Furthermore, the addition of carbon monoxide increases the concentration of H radical owing to the intensified forward rate of the reaction CO + OH = CO{sub 2} + H and therefore increases the surface growth reaction rates. The addition of carbon monoxide also slows the oxidation rate of soot because the same reaction CO + OH = CO{sub 2} + H results in a lower concentration of OH. (author)

  1. Duct injection for SO{sub 2} control, Design Handbook, Volume 1, Process design and engineering guidelines

    SciTech Connect

    1995-09-01

    PETC developed a comprehensive program of coal-related, acid-rain research and development with a major activity area centering on flue gas cleanup and control of SO{sub 2} emissions. Particular emphasis was placed on the retrofit measures for older coal-fired power plants which predate the 1971 New Source Performance Standards. Candidate emission control technologies fall into three categories, depending upon their point of application along the fuel path (i.e., pre, during, or post combustion). The post-combustion, in-duct injection of a calcium-based chemical reagent seemed promising. Preliminary studies showed that reagent injection between the existing air heater and electrostatic precipitator (ESP) could remove between 50-60% of the SO{sub 2} and produce an environmentally safe, dry, solid waste that is easily disposed. Although SO{sub 2} removal efficiencies were less, the estimated capital costs for duct injection technology were low making the economics of duct injection systems seem favorable when compared to conventional wet slurry scrubbers under certain circumstances. With the promulgation of the Clean Air Act Amendments of 1990 came more incentive for the development of low capital cost flue gas desulfurization (FGD) processes. A number of technical problems had to be resolved, however, before duct injection technology could be brought to a state of commercial readiness. The Duct Injection Technology Development Program was launched as a comprehensive, four-year research effort undertaken by PETC to develop this new technology. Completed in 1992, this Duct Injection Design Handbook and the three-dimensional predictive mathematical model constitute two primary end products from this development program. The aim of this design handbook and the accompanying math model is to provide utility personnel with sufficient information to evaluate duct injection technology against competing SO{sub 2} emissions reduction strategies for an existing plant.

  2. 40 CFR 49.5 - Tribal requests for additional Clean Air Act provisions for which it is not appropriate to treat...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... additional Clean Air Act provisions for which it is not appropriate to treat tribes in the same manner as States. Any tribe may request that the Administrator specify additional provisions of the Clean Air Act... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Tribal requests for additional...

  3. 40 CFR 49.5 - Tribal requests for additional Clean Air Act provisions for which it is not appropriate to treat...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... additional Clean Air Act provisions for which it is not appropriate to treat tribes in the same manner as States. Any tribe may request that the Administrator specify additional provisions of the Clean Air Act... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Tribal requests for additional...

  4. 40 CFR 49.5 - Tribal requests for additional Clean Air Act provisions for which it is not appropriate to treat...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... additional Clean Air Act provisions for which it is not appropriate to treat tribes in the same manner as States. Any tribe may request that the Administrator specify additional provisions of the Clean Air Act... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Tribal requests for additional...

  5. 40 CFR 49.5 - Tribal requests for additional Clean Air Act provisions for which it is not appropriate to treat...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... additional Clean Air Act provisions for which it is not appropriate to treat tribes in the same manner as States. Any tribe may request that the Administrator specify additional provisions of the Clean Air Act... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Tribal requests for additional...

  6. Addition of PM 2.5 into the national ambient air quality standards of China and the contribution to air pollution control: the case study of Wuhan, China.

    PubMed

    You, Mingqing

    2014-01-01

    PM2.5 has gradually become a major environmental problem of China with its rapid economic development, urbanization, and increasing of motor vehicles. Findings and awareness of serious PM2.5 pollution make the PM2.5 a new criterion pollutant of the Chinese National Ambient Air Quality Standard (NAAQS) revised in 2012. The 2012 NAAQS sets the PM2.5 concentrate limitation with the 24-hour average value and the annual mean value. Wuhan is quite typical among central and southern China in climate, economy, development level, and energy consumption. The data are cited from the official website of Wuhan Environmental Protection Bureau and cover the period from 1 January to 30 June 2013. The data definitely confirm the existence of serious PM2.5 pollution in Wuhan and indicate that the addition of PM2.5 as a criterion pollutant significantly brings down the attainment rate of air quality. The example of Wuhan reveals that local governments should take measures to reduce the emission of PM2.5 if it affects the attainment rate and the performance evaluation value of air quality. The main contribution of 2012 NAAQS is that it brings down the attainment rate of the air quality and forces local governmental officials to take the measures accordingly.

  7. Addition of PM2.5 into the National Ambient Air Quality Standards of China and the Contribution to Air Pollution Control: The Case Study of Wuhan, China

    PubMed Central

    You, Mingqing

    2014-01-01

    PM2.5 has gradually become a major environmental problem of China with its rapid economic development, urbanization, and increasing of motor vehicles. Findings and awareness of serious PM2.5 pollution make the PM2.5 a new criterion pollutant of the Chinese National Ambient Air Quality Standard (NAAQS) revised in 2012. The 2012 NAAQS sets the PM2.5 concentrate limitation with the 24-hour average value and the annual mean value. Wuhan is quite typical among central and southern China in climate, economy, development level, and energy consumption. The data are cited from the official website of Wuhan Environmental Protection Bureau and cover the period from 1 January to 30 June 2013. The data definitely confirm the existence of serious PM2.5 pollution in Wuhan and indicate that the addition of PM2.5 as a criterion pollutant significantly brings down the attainment rate of air quality. The example of Wuhan reveals that local governments should take measures to reduce the emission of PM2.5 if it affects the attainment rate and the performance evaluation value of air quality. The main contribution of 2012 NAAQS is that it brings down the attainment rate of the air quality and forces local governmental officials to take the measures accordingly. PMID:24982994

  8. Economics of pollution trading for SO{sub 2} and NOx

    SciTech Connect

    Dallas Burtraw; David A. Evans; Alan Krupnick; Karen Palmer; Russell Toth

    2005-03-15

    For years economists have urged policymakers to use market-based approaches such as cap-and-trade programs or emission taxes to control pollution. The sulphur dioxide (SO{sub 2}) allowance market created by Title IV of the 1990 US Clean Air Act Amendments represents the first real test of the wisdom of economists' advice. Subsequent urban and regional applications of NOx emission allowance trading took shape in the 1990s in the United States, culminating in a second large experiment in emission trading in the eastern United States that began in 2003. This paper provides an overview of the economic rationale for emission trading and a description of the major US programs for SO{sub 2} and nitrogen oxides. These programs are evaluated along measures of performance including cost savings, environmental integrity, and incentives for technological innovation. The authors offer lessons for the design of future programs including, most importantly, those reducing carbon dioxide. 128 refs., 1 fig., 1 tab.

  9. Development of the advanced coolside sorbent injection process for SO{sub 2}

    SciTech Connect

    Withum, J.A.; Maskew, J.T.; Rosenhoover, W.A.

    1995-11-01

    The goal of this work was to develop a low-capital-cost process capable of over 90% SO{sub 2} removal as an economically attractive option for compliance with the Clean Air Act. The Advanced Coolside Process uses a contactor to simultaneously remove fly ash and saturate the flue gas with water, followed by sorbent injection into the highly humid flue gas and collection of the sorbent by the existing particulate collector High sorbent utilization is achieved by sorbent recycle. The original performance targets of 90% SO{sub 2} removal and 60% sorbent utilization were exceeded in 1000 acfm pilot plant operations using commercial hydrated lime as the only sorbent. Process optimization simplified the process equipment, resulting in significant cost reduction. Recent accomplishments include completion of equipment testing and sorbent optimization, a waste management study, and a long-term performance test. An economic evaluation for the optimized process projects capital costs 55% to 60 % less than those of limestone forced oxidation wet FGD. The projected levelized control cost is 15% to 35% lower than wet FGD (25% lower for a 260 MWe plant burning a 2.5% sulfur coal), depending on plant size and coal sulfur content.

  10. Effect of SO>2 on oxidation of metallic materials in CO2/H2O-rich gases relevant to oxyfuel environments

    SciTech Connect

    Huczkowski, P.; Olszewski, T.; Schiek, M.; Lutz, B.; Holcomb, G.; Shemet, V.; Meier, G. H.; Singheiser, L.; Quadakkers, W. J.

    2012-09-19

    This report is a description of research performed by the Jülich Research Centre. Their conclusions outline the effects of SO>2 additions on oxide formations and the interaction of other gases in oxvyfuel environments.

  11. Effects of CO addition on the characteristics of laminar premixed CH{sub 4}/air opposed-jet flames

    SciTech Connect

    Wu, C.-Y.; Chao, Y.-C.; Chen, C.-P.; Ho, C.-T.; Cheng, T.S.

    2009-02-15

    The effects of CO addition on the characteristics of premixed CH{sub 4}/air opposed-jet flames are investigated experimentally and numerically. Experimental measurements and numerical simulations of the flame front position, temperature, and velocity are performed in stoichiometric CH{sub 4}/CO/air opposed-jet flames with various CO contents in the fuel. Thermocouple is used for the determination of flame temperature, velocity measurement is made using particle image velocimetry (PIV), and the flame front position is measured by direct photograph as well as with laser-induced predissociative fluorescence (LIPF) of OH imaging techniques. The laminar burning velocity is calculated using the PREMIX code of Chemkin collection 3.5. The flame structures of the premixed stoichiometric CH{sub 4}/CO/air opposed-jet flames are simulated using the OPPDIF package with GRI-Mech 3.0 chemical kinetic mechanisms and detailed transport properties. The measured flame front position, temperature, and velocity of the stoichiometric CH{sub 4}/CO/air flames are closely predicted by the numerical calculations. Detailed analysis of the calculated chemical kinetic structures reveals that as the CO content in the fuel is increased from 0% to 80%, CO oxidation (R99) increases significantly and contributes to a significant level of heat-release rate. It is also shown that the laminar burning velocity reaches a maximum value (57.5 cm/s) at the condition of 80% of CO in the fuel. Based on the results of sensitivity analysis, the chemistry of CO consumption shifts to the dry oxidation kinetics when CO content is further increased over 80%. Comparison between the results of computed laminar burning velocity, flame temperature, CO consumption rate, and sensitivity analysis reveals that the effect of CO addition on the laminar burning velocity of the stoichiometric CH{sub 4}/CO/air flames is due mostly to the transition of the dominant chemical kinetic steps. (author)

  12. Sulfur chemistry in the envelope of VY Canis Majoris: Detailed analysis of SO and SO{sub 2} emission

    SciTech Connect

    Adande, G. R.; Edwards, J. L.; Ziurys, L. M.

    2013-11-20

    Detailed radiative transfer modeling has been carried out for SO{sub 2} and SO originating in the envelope of the O-rich supergiant star VY Canis Majoris (VY CMa). A total of 27 transitions of SO{sub 2} and 7 transitions of SO lying in the energy range 3.0-138.2 cm{sup –1} were analyzed using a new non-LTE radiative transfer code that incorporates non-spherical geometries. The spectra were primarily obtained from the Arizona Radio Observatory (ARO) 1 mm spectral survey of VY CMa, conducted with the Submillimeter Telescope; additional lines were measured with the ARO 12 m antenna at 2 and 3 mm. SO{sub 2} and SO were found to arise from five distinct outflows within the envelope, four which are asymmetric with respect to the star. Three flows arise from high-velocity red-shifted material, one from a blue-shifted wind, and the final from a classic 'spherical' expansion. In the spherical component, the peak fractional abundance, relative to H{sub 2}, of both molecules is f ∼ 2.5 × 10{sup –7} at r ∼ 25 R {sub *}, and steadily decreases outward. SO{sub 2} appears to be a 'parent' molecule, formed near the stellar photosphere. In the asymmetric outflows, both SO and SO{sub 2} are more prominent at large stellar radii in dense (10{sup 6}-10{sup 7} cm{sup –3}), clumpy material, achieving their maximum abundance between 200 and 600 R {sub *} with f ∼ 3.0 × 10{sup –8}-1.5 × 10{sup –7}. These results suggest that in the collimated outflows, both species are either produced by shock chemistry or are remnant inner shell material swept up in the high-velocity winds.

  13. Boundary lubrication of formulated C-ethers in air to 300 C. 2: Organic acid additives

    NASA Technical Reports Server (NTRS)

    Jones, W. R., Jr.

    1973-01-01

    Friction and wear measurements were made on CVM M-50 steel lubricated with three C-ether (modified polyphenyl ether) formulations in dry and moist air. Results were compared to those obtained with a formulated Type 2 ester and the C-ether base fluid. A ball-on-disk sliding friction apparatus was used. Experimental conditions were a 1-kilogram load, a 17-meter/minute surface speed, and a 25 to 300 C (77 to 572 F) disk temperature range. The three C-ether formulations yielded better boundary lubricating characteristics than the Type 2 ester under most test conditions. All C-ether formulations exhibited higher friction coefficients than the ester from 150 to 300 C (302 to 572 F) and similar or lower values from 25 to 150 C (77 to 302 F).

  14. Performance of AA5052 alloy anode in alkaline ethylene glycol electrolyte with dicarboxylic acids additives for aluminium-air batteries

    NASA Astrophysics Data System (ADS)

    Wang, DaPeng; Zhang, DaQuan; Lee, KangYong; Gao, LiXin

    2015-11-01

    Dicarboxylic acid compounds, i.e. succinic acid (SUA), adipic acid (ADA) and sebacic acid (SEA), are used as electrolyte additives in the alkaline ethylene glycol solution for AA5052 aluminium-air batteries. It shows that the addition of dicarboxylic acids lowers the hydrogen gas evolution rate of commercial AA5052 aluminium alloy anode. AA5052 aluminium alloy has wide potential window for electrochemical activity and better discharge performance in alkaline ethylene glycol solution containing dicarboxylic acid additives. ADA has the best inhibition effect for the self-corrosion of AA5052 anode among the three dicarboxylic acid additives. Fourier transform infrared spectroscopy (FT-IR) reveals that dicarboxylic acids and aluminium ions can form coordination complexes. Quantum chemical calculations shows that ADA has a smaller energy gap (ΔE, the energy difference between the lowest unoccupied orbital and the highest occupied orbital), indicating that ADA has the strongest interaction with aluminium ions.

  15. Commercial demonstration of the NOXSO SO{sub 2}/NO{sub x} removal flue gas cleanup system. Quarterly technical progress report No. 15, September 1, 1994--November 30, 1994

    SciTech Connect

    1997-01-01

    The objective of the NOXSO Demonstration Project (NDP), with cost-shared funding support from DOE, is to design, construct, and operate a commercial-scale flue gas cleanup system utilizing the NOXSO process. The NDP consists of the NOXSO plant and sulfur recovery unit, designed to remove SO{sub 2} and NO{sub x} from flue gas and produce elemental sulfur by-product, and the liquid SO{sub 2} plant and air separation unit, designed to process the elemental sulfur into liquid SO{sub 2}. The NOXSO plant and sulfur recovery unit will be constructed at ALCOA Generating Corporation`s (AGC) Warrick Power Plant near Evansville, Indiana, and will treat all of the flue gas from the 150-MW Unit 2 boiler. The elemental sulfur produced will be shipped to the Olin Charleston Plant in Charleston, Tennessee, for conversion into liquid SO{sub 2}.

  16. A PRINCIPAL COMPONENT ANALYSIS OF THE CLEAN AIR STATUS AND TRENDS NETWORK (CASTNET) AIR CONCENTRATION DATA

    EPA Science Inventory

    The spatial and temporal variability of ambient air concentrations of SO>2, SO>42-, NO3, HNO3, and NH4+ obtained from EPA's CASTNet was examined using an objective, statistically based technique...

  17. Humidification of flue gas to augment SO/sub 2/ capture by dry sorbents. Repprt for October 1985-July 1988 (Final)

    SciTech Connect

    Gooch, J.P.; Beittel, R.; Dimukes, E.B.; Dahlin, R.S.

    1989-03-01

    This report discusses, for a coal-burning power plant, using humidification of the flue gas in a low-temperature duct to increase SO/sub 2/ removal by dry calcium-based sorbents. In particular, humidification may be a desirable modification of EPA's LIMB process, which is based on injecting limestone or hydrated lime in the furnace; it could augment SO/sub 2/ removal by adding post-furnace removal to that occurring in the injection zone. The report covers work in post-furnace humidification, charge-augmented humidification, water vapor adsorption by lime (with and without additives), and mathematical modeling of humidification and SO/sub 2/ removal processes. From these investigations, it was concluded that, for enhancement of SO/sub 2/ capture at the Edgewater demonstration of LIMB, humidification by a water spray will be required. A spray of pure water would suffice if the frequency of collisions between sorbent particles and water droplets could be increased. Deliquescent additives that are known to enhance SO/sub 2/ capture by Ca(OH)/sub 2/ at low temperatures must operate to some extent by mechanisms other than deliquescence.

  18. Optimization of the integrated citric acid-methane fermentation process by air stripping and glucoamylase addition.

    PubMed

    Xu, Jian; Chen, Yang-Qiu; Zhang, Hong-Jian; Wang, Ke; Tang, Lei; Zhang, Jian-Hua; Chen, Xu-Sheng; Mao, Zhong-Gui

    2015-03-01

    To solve the problem of extraction wastewater in citric acid industry, an integrated citric acid-methane fermentation process was proposed. In the integrated process, extraction wastewater was treated by mesophilic anaerobic digestion and then reused to make mash for the next batch of citric acid fermentation. In this study, an Aspergillus niger mutant strain exhibiting resistance to high metal ions concentration was used to eliminate the inhibition of 200 mg/L Na(+) and 300 mg/L K(+) in anaerobic digestion effluent (ADE) and citric acid production increased by 25.0 %. Air stripping was used to remove ammonium, alkalinity, and part of metal ions in ADE before making mash. In consequence, citric acid production was significantly improved but still lower by 6.1 % than the control. Results indicated that metal ions in ADE synergistically inhibited the activity of glucoamylase, thus reducing citric acid production. When 130 U/g glucoamylase was added before fermentation, citric acid production was 141.5 g/L, which was even higher than the control (140.4 g/L). This process could completely eliminate extraction wastewater discharge and reduce water resource consumption.

  19. Additional research on instabilities in atmospheric flow systems associated with clear air turbulence

    NASA Technical Reports Server (NTRS)

    Stoeffler, R. C.

    1972-01-01

    Analytical and experimental fluid mechanics studies were conducted to investigate instabilities in atmospheric flow systems associated with clear air turbulence. The experimental portion of the program was conducted using an open water channel which allows investigation of flows having wide ranges of shear and density stratification. The program was primarily directed toward studies of the stability of straight, stratified shear flows with particular emphasis on the effects of velocity profile on stability; on studies of three-dimensional effects on the breakdown region in shear layers; on the the interaction of shear flows with long-wave length internal waves; and on the stability of shear flows consisting of adjacent stable layers. The results of these studies were used to evaluate methods used in analyses of CAT encounters in the atmosphere involving wave-induced shear layer instabilities of the Kelvin-Helmholta type. A computer program was developed for predicting shear-layer instability and CAT induced by mountain waves. This technique predicts specific altitudes and locations where CAT would be expected.

  20. Modeling of SO{sub 2} absorption into limestone suspensions

    SciTech Connect

    Lancia, A.; Musmarra, D.; Pepe, F.

    1997-01-01

    The wet limestone flue gas desulfurization process, and more specifically absorption of SO{sub 2} limestone suspensions, was studied. Experiments of SO{sub 2} absorption were carried out using a bubbling reactor with a mixture of sulfur dioxide and nitrogen in the gas phase and an aqueous limestone suspension in the liquid phase. The SO{sub 2} absorption rate was measured at different compositions of both gas and liquid phases and at different gas flow rates and agitator speeds. A model based on the film theory was proposed to describe liquid-side mass transfer. It was assumed that the liquid-phase diffusional resistance is concentrated in a layer, the thickness of which depends on fluid dynamics, but is independent of the nature of the reactions taking place. The equations considered by the model describe conditions of thermodynamic equilibrium as well as material and electrical balances and use the experimentally determined gas- and liquid-side mass-transfer coefficients, rather than empirical parameters. Model calculations and experimental results were compared, and a good consistency was found. Eventually the model was used to evaluate the absorption enhancement factor as a function of gas- and liquid-phase composition.

  1. Simultaneous SO{sub 2}/NO separation from flue gas using HFCLM. Final report

    SciTech Connect

    Schimmel, K.

    1995-02-01

    Abatement technologies for oxides of sulfur and nitrogen present in flue and stack gases from coal fired boilers are becoming increasingly important. Scrubbing the gases with an aqueous limestone slurry to remove SO{sub 2} is a widely used treatment process. These scrubbing solutions are, however, not very effective in removing NO. In addition, the process is expensive and produces large volumes of sludge. The liquid membrane from a 0.01 M aqueous solution of Fe{sup 2+}EDTA has been found to have a very high selectivity for NO over N{sub 2}. Thus, SO{sub 2}/NO{sub x} can be removed simultaneously using an aqueous Fe 3{sup 3+}EDTA solution in a hollow fiber contained liquid membrane (HFCLM) permeator with hydrophobic fibers. The HFCLM configuration has addressed previous concerns about liquid membrane stability for an application such as this. In this project, a flow apparatus was constructed that will allow simultaneous SO{sub 2}/NO removal and recovery using two hollow fiber modules in series. Flowing the liquid membrane on the shell-side of the modules it is hypothesized will enhance the performance over that of HFCLMs without loss of stability. From the work completed in this exploratory project, it was concluded that to move the current state-of-the-art for this promising technology toward commercialization will require progress in the following areas: (1) sensitivity of the performance of the system to temperature changes, (2) validation of a mass transfer model to be used in scale-up calculations, (3) data on alternative flow schemes, and (4) overall process economics calculations.

  2. A Delphi Study of Additive Manufacturing Applicability for United States Air Force Civil Engineer Contingency Operations

    DTIC Science & Technology

    2015-03-26

    This simple process is the basis for most consumer-grade desktop AM machines, commonly known as 3D printers (Pham & Gault, 1998:1270). Material...as a single purchase to decrease initial capital costs. Once the 3D printers are purchased and delivered, the selected bases can begin training...for several Questions if you would liKe to explain or elaborate on your answers. Additional information •out 3D printers and UTCs is provided as an

  3. Task 2.0 -- Air quality assessment, control, and analytical methods: Subtask 2.11 -- Lactic acid FGD additives from sugar beet wastewater. Final report

    SciTech Connect

    Olson, E.S.

    1998-06-01

    Organic buffers maintain the pH of the scrubber slurry in flue gas desulfurization as the SO{sub 2} dissolves at the air-liquid interface. Inexpensive acids with an appropriate pKa are required for this application. The pKa of lactic acid (3.86) is between that of the interface and the recirculating slurry and will make soluble calcium ions available in large amounts. Currently lactic acid is somewhat expensive for this, but the project work will lead to development of a new source of inexpensive lactate. Microbial action during the storage and processing of sugar beets forms lactic acid in concentrations as high as 14 g/L in the processing water. The concentrations are lower than those occurring in conventional fermentation production of lactic acids, but since a considerable amount of water is involved in the processing of sugar beets in the Red River Valley, a substantial amount of lactic acid or calcium lactate could be recovered as a byproduct for use in flue gas desulfurization (FGD) and other applications. The feasibility of two novel lactate recovery schemes applicable to dilute streams was evaluated in the project.

  4. Nitrogen-Doped Co3 O4 Mesoporous Nanowire Arrays as an Additive-Free Air-Cathode for Flexible Solid-State Zinc-Air Batteries.

    PubMed

    Yu, Minghao; Wang, Zhengke; Hou, Cheng; Wang, Zilong; Liang, Chaolun; Zhao, Cunyuan; Tong, Yexiang; Lu, Xihong; Yang, Shihe

    2017-04-01

    The kinetically sluggish rate of oxygen reduction reaction (ORR) on the cathode side is one of the main bottlenecks of zinc-air batteries (ZABs), and thus the search for an efficient and cost-effective catalyst for ORR is highly pursued. Co3 O4 has received ever-growing interest as a promising ORR catalyst due to the unique advantages of low-cost, earth abundance and decent catalytic activity. However, owing to the poor conductivity as a result of its semiconducting nature, the ORR activity of the Co3 O4 catalyst is still far below the expectation. Herein, we report a controllable N-doping strategy to significantly improve the catalytic activity of Co3 O4 for ORR and demonstrate these N doped Co3 O4 nanowires as an additive-free air-cathode for flexible solid-state zinc-air batteries. The results of experiments and DFT calculations reveal that the catalytic activity is promoted by the N dopant through a combined set of factors, including enhanced electronic conductivity, increased O2 adsorption strength and improved reaction kinetics. Finally, the assembly of all-solid-state ZABs based on the optimized cathode exhibit a high volumetric capacity of 98.1 mAh cm(-3) and outstanding flexibility. The demonstration of such flexible ZABs provides valuable insights that point the way to the redesign of emerging portable electronics.

  5. Making appropriate comparisons of estimated and actual costs of reducing SO{sub 2} emissions under Title IV

    SciTech Connect

    Smith, A.E.

    1998-12-31

    A current sentiment within some parts of the environmental policy community is that market-based regulatory approaches such as emissions trading have proven so effective that actual costs will be only a small fraction of what ex ante cost estimation procedures would project. With this line of reasoning, some have dismissed available cost estimates for major proposed new regulations, such as the new PM and ozone NAAQS, as not meaningful for policy decisions. The most commonly used evidence in support of this position is the experience with SO{sub 2} reductions under Title IV of the 1990 Clean Air Act Amendments. In Title IV, a market for emissions allowances has been used to achieve reductions in sulfur dioxides (SO{sub 2}) to ameliorate acid rain. It is commonly asserted today that the cost of achieving the SO{sub 2} emissions reductions has been only one-tenth or less of what Title IV was originally expected to cost. This paper demonstrates that, to the contrary, actual costs for SO{sub 2} reductions remain roughly in line with original estimates associated with Title IV. Erroneous conclusions about Title IV`s costs are due to inappropriate comparisons of a variety of different measures that appear to be comparable only because they are all stated in dollars per ton. Program cost estimates include the total costs of a fully-implemented regulatory program. The very low costs of Title IV that are commonly cited today are neither directly reflective of a fully implemented Title IV, (which is still many years away) nor reflective of all the costs already incurred. Further, a careful review of history finds that the initial cost estimates that many cite were never associated with Title IV. Technically speaking, people are comparing the estimated control costs for the most-costly power plant associated with earlier acid rain regulatory proposals with prices from a market that do not directly reflect total costs.

  6. Effect of additional heat treatment of 2024-T3 on the growth of fatigue crack in air and in vacuum

    NASA Technical Reports Server (NTRS)

    Louwaard, E. P.

    1986-01-01

    In order to determine the influence of ductility on the fatigue crack growth rate of aluminum alloys, fatigue tests were carried out on central notched specimens of 2024-T3 and 2024-T8 sheet material. The 2024-T8 material was obtained by an additional heat treatment applied on 2024-T3 (18 hours at 192 C), which increased the static yield strength from 43.6 to 48.9 kgf/sq mm. A change in the ultimate strength was not observed. Fatigue tests were carried out on both materials in humid air and in high vacuum. According to a new crack propagation model, crack extension is supported to be caused by a slip-related process and debonding triggered by the environment. This model predicts an effect of the ductility on the crack growth rate which should be smaller in vacuum than in humid air; however, this was not confirmed. In humid air the crack-growth rate in 2024-T8 was about 2 times faster than in 2024-T3, while in vacuum the ratio was about 2.5. Crack closure measurements gave no indications that crack closure played a significant role in both materials. Some speculative explanations are briefly discussed.

  7. LIFAC flue gas desulfurization process an alternative SO{sub 2} control strategy

    SciTech Connect

    Patel, J.G.; Vilala, J.

    1995-12-01

    This paper discusses the results from two recently completed LIFAC flue gas desulfurization plants - 300 MW Shand lignite powered station owned by Saskatchewan Power Corporation and 60 MW Whitewater Valley high sulfur coal fired station owned by Richmond Powerand Light. LIFACis a dry FGD process in which limestone is injected into the upper regions of the boiler furnace and an activation reactor is used to humidify the unreacted limestone to achieve additional sulfur capture. The performance in both plants indicates that 70 to 80% sulfur is removed at a Ca/S ratio of 2. Cost performance data from these plants has shown that LI FAC both on construction cost and $/ton SO{sub 2} removed basis is very cost competitive compared to other SO{sub 2} control technologies. The Richmond plant has been realized under the auspices of the U.S. Department of Energy`s Clean Coal Technology program. The Shand plant is the first commercial installation in North America. The paper also discusses highlights of operating and maintenance experience, availability and handling of the solid waste product.

  8. Effects of inhaled sulfur dioxide (SO/sub 2/) on pulmonary function in healthy adolescents: exposure to SO/sub 2/ alone or SO/sub 2/ + sodium chloride droplet aerosol during rest and exercise

    SciTech Connect

    Koenig, J.Q.; Pierson, W.E.; Horike, M.; Frank, R.

    1982-01-01

    Statistically significant changes in pulmonary functional measurements in asthmatic adolescents exposed to sulfur dioxide (SO/sub 2/) at reset and during exercise were recently reported. To determine whether those results were due to the subjects' adolescence or to their asthma, the identical exposures were repeated in healthy adolescents. The healthy subjects showed small, statistically significant changes after exposure to SO/sub 2/, but these changes were slight compared to those seen in the asthmatic adolescents. It was concluded that asthmatic adolescents are much more sensitive to the effects of inhaled SO/sub 2/ than are healthy adolescents. (JMT)

  9. Process for removing SO/sub x/ and NO/sub x/ compounds from gas streams

    SciTech Connect

    Hass, R.H.

    1989-02-14

    A process is described for removing SO/sub x/ compounds from a feed gas stream and producing a purified gas stream of reduced SO/sub x/ content, which process comprises: contacting a feed gas stream containing SO/sub x/ compounds; withdrawing from step (1) a liquid stream of spent absorbent containing the absorbed SO/sub x/ compounds; regenerating the spent absorbent back to a form active for absorbing SO/sub x/ compounds; separating the products of step (3) into a liquid stream containing a regenerated absorbent and a product gas stream containing H/sub 2/S; recycling at least some of the liquid stream containing regenerated absorbent; and recovering the purified gas stream of reduced SO/sub x/ content and the product gas stream containing H/sub 2/S.

  10. Apparatus and method for improving electrostatic precipitator performance by plasma reactor conversion of SO.sub.2 to SO.sub.3

    DOEpatents

    Huang, Hann-Sheng; Gorski, Anthony J.

    1999-01-01

    An apparatus and process that utilize a low temperature nonequilibrium plasma reactor, for improving the particulate removal efficiency of an electrostatic precipitator (ESP) are disclosed. A portion of the flue gas, that contains a low level of SO.sub.2 O.sub.2 H.sub.2 O, and particulate matter, is passed through a low temperature plasma reactor, which defines a plasma volume, thereby oxidizing a portion of the SO.sub.2 present in the flue gas into SO.sub.3. An SO.sub.2 rich flue gas is thereby generated. The SO.sub.3 rich flue gas is then returned to the primary flow of the flue gas in the exhaust treatment system prior to the ESP. This allows the SO.sub.3 to react with water to form H.sub.2 SO.sub.4 that is in turn is absorbed by fly ash in the gas stream in order to improve the removal efficiency of the EPS.

  11. Effects of SO/sub 2/ and ozone on crop physiology and productivity. Final report

    SciTech Connect

    Laeuchli, A.; Timm, H.

    1985-08-26

    Growth and productivity of several crop cultivars were related to physiological and biochemical parameters. In laboratory studies seed germination was not sensitive to SO/sub 2/ and ozone but root growth was sensitive. SO/sub 2/ inhibited pollen tube growth; ozone had no effect on pollen viability. Differential SO/sub 2/ sensitivity in corn cultivars was related to cellular uptake and detoxification. SO/sub 2/ induced ethylene production in a sensitive corn cultivar without visible injury. In bean cultivars sensitivity to ozone was correlated with stomatal uptake. Ozone decreased plant growth and pod yield, and lowered leaf water potential prior to bloom.

  12. Predictive models of circulating fluidized bed combustors: SO{sub 2} sorption in the CFB loop. Fourteenth technical progress report

    SciTech Connect

    Gidaspow, D.; Therdthianwong, A.

    1993-02-01

    The overall objective of this investigation is to develop experimentally verified models for circulating fluidized bed (CFB) combustors. Sorption of S0{sub 2} with calcined limestone was studied in a PYROFLOW type CFB loop at conditions approximating those found in a CFB combustor. Initially the CFB loop contained 150 micron CaO particles of a density of 3.3 g/cm{sup 3} and air at 1143{degrees}K and 3.25 atm. Atzero time, air containing 600 ppm SO{sub 2}, was introduced into the riser bottom at 1143{degrees}K. The effect of gas velocity, sorbent inventory and inlet pressure on the sorption of SO{sub 2}, were studied isothermally by running our hydrodynamic code with the S0{sub 2} sorption conservation of species equation. At a velocity of 5m/sec., reported to be a typical velocity by PYROPOWER, there is reasonably good S0{sub 2} removal. At 10 m/sec the S0{sub 2} removal is poor. The best SO{sub 2}, removal is for a velocity of 5 m/s and a high bed inventory, initial bed height, H = 9m. Most of the S0{sub 2} is removed in the first two meters of the reactor. However, the S0{sub 2} removal is not complete at the bed outlet. This is due to mixing. At the left wall of the reactor (wall opposite the solids inlet) the S0{sub 2} removal was poor due to gas bypassing caused by the asymmetrical solids inlet. Simulation of the PYROPOWER loop with a symmetrical inlet gave us an order of magnitude improvement over the conventional PYROPOWER system. These results demonstrate the practical utility of the predictive model that we have developed over the last three years.

  13. Strain-induced extinction of hydrogen-air counterflow diffusion flames - Effects of steam, CO2, N2, and O2 additives to air

    NASA Technical Reports Server (NTRS)

    Pellett, G. L.; Northam, G. B.; Wilson, L. G.

    1992-01-01

    A fundamental study was performed using axisymmetric nozzle and tubular opposed jet burners to measure the effects of laminar plug flow and parabolic input velocity profiles on the extinction limits of H2-air counterflow diffusion flames. Extinction limits were quantified by 'flame strength', (average axial air jet velocity) at blowoff of the central flame. The effects of key air contaminants, on the extinction limits, are characterized and analyzed relative to utilization of combustion contaminated vitiated air in high enthalpy supersonic test facilities.

  14. Study on the adsorption properties of O{sub 3}, SO{sub 2}, and SO{sub 3} on B-doped graphene using DFT calculations

    SciTech Connect

    Rad, Ali Shokuhi; Shabestari, Sahand Sadeghi; Mohseni, Soheil; Aghouzi, Samaneh Alijantabar

    2016-05-15

    We investigated the structure, adsorption, electronic states, and charge transfer of O{sub 3}, SO{sub 2} and SO{sub 3} molecules on the surface of a B-doped graphene using density functional theory (DFT). We found weak physisorption of SO{sub 2} (−10.9 kJ/mole, using B3LYP-D) and SO{sub 3} (−15.7 kJ/mole, using B3LYP-D) on the surface of B-doped graphene while there is strong chemisorption for O{sub 3} (−96.3 kJ/mole, using B3LYP-D ) on this surface. Our results suggest the potential of B-doped graphene as a selective sensor/adsorbent for O{sub 3} molecule. We noticed some change in hybridizing of boron from sp{sup 2} to sp{sup 3} upon adsorption of O{sub 3} which cases transformation of the adsorbent from 2D to 3D. - Graphical abstract: The electronic property of B-doped graphene is responsible to highly adsorption of O{sub 3} molecules while the adsorption of SO{sub 2} and SO{sub 3} molecules on this surface exhibits only a weak interaction. - Highlights: • B-doped graphene clearly is n-type semiconductor. • High negatively charge of C-atoms neighboring the boron dopant. • Chemisorption of O{sub 3} and physisorption of SO{sub 2} and SO{sub 3} on the surface of B-doped graphene.

  15. Enhancing biochar yield by co-pyrolysis of bio-oil with biomass: impacts of potassium hydroxide addition and air pretreatment prior to co-pyrolysis.

    PubMed

    Veksha, Andrei; Zaman, Waheed; Layzell, David B; Hill, Josephine M

    2014-11-01

    The influence of KOH addition and air pretreatment on co-pyrolysis (600 °C) of a mixture of bio-oil and biomass (aspen wood) was investigated with the goal of increasing biochar yield. The bio-oil was produced as a byproduct of the pyrolysis of biomass and recycled in subsequent runs. Co-pyrolysis of the biomass with the recycled bio-oil resulted in a 16% mass increase in produced biochar. The yields were further increased by either air pretreatment or KOH addition prior to co-pyrolysis. Air pretreatment at 220 °C for 3 h resulted in the highest mass increase (32%) compared to the base case of pyrolysis of biomass only. No synergistic benefit was observed by combining KOH addition with air pretreatment. In fact, KOH catalyzed reactions that increased the bed temperature resulting in carbon loss via formation of CO and CO2.

  16. A reversible zwitterionic SO>2-binding organic liquid

    SciTech Connect

    Heldebrant, David J; Koech, Phillip K; Yonker, Clement R

    2010-01-05

    As fossil fuel consumption continues, there is much attention being focused on capturing acid gas emissions from power plants. We have recently investigated SO>2-binding organic liquids (SO>2BOLs) as means to reversibly capture and release SO>2 selectively over CO2.1 SO>2BOLs are mixtures of tertiary amines and alcohols, which bind SO>2 as liquid ammonium alkylsulfite salts. Tertiary amines selectively bind SO>2 over CO2 because tertiary amines are basic enough to accept a proton from sulfurous and alkylsulfurous acids but not carbonic or alkylcarbonic acids. This is in contrast to other groups who absorb SO>2 physically in ionic liquids2-4 or chemically absorb SO>2 in organic systems5-7 or as irreversible aqueous bisulfite or sulfite salts.8-11 Our dual component SO>2BOL ionic liquids can contain up to 47% SO>2 by mass, have low specific heats, and can be desulfoxylated by heating to 90ºC.1 We believed that a bifunctional tertiary alkanol amine would be able to capture SO>2 comparable to our binary SO>2BOL system. We present here the first reversible zwitterionic liquid produced from the reaction of SO>2 with N,N-dibutylundecanolamine (DBUA). The SO>2 is chemically bound through the alcohol moiety as an alkylsulfite, which we believe is stabilized by hydrogen bonding through the protonated amine portion of the molecule. Our recent interest in SO>2BOLs led us to explore the possible reaction of aprotic alkanolamines with SO>2 to form single-component SO>2BOLs. A symbiotic pairing of the base and the alcohol on one molecule allows for a simple unimolecular system compared to the binary SO>2BOL system. The bifunctional molecule also would have reduced volatility compared to tertiary amines due to increased hydrogen bonding from the alcohol moiety. To our knowledge

  17. Emerging flue-gas cleanup technologies for combined control of SO{sub 2} and NO{sub x}

    SciTech Connect

    Livengood, C.D.; Markussen, J.M.

    1994-06-01

    Enactment of the 1990 Clean Air Act Amendments, as well as passage of legislation at the state level has raised the prospect of more stringent nitrogen oxides (NO{sub x}) emission regulations and has fueled research and development efforts on a number technologies for the combined control of sulfur dioxide (SO{sub 2}) and NO{sub x}. The integrated removal of both SO{sub 2} and NO{sub x} in a single system can offer significant advantages over the use of several separate processes, including such factors as reduced system complexity, better operability, and lower costs. This paper reviews the status of a number of integrated flue-gas-cleanup systems that have reached a significant stage of development, focusing on post-combustion processes that have been tested or are ready for testing at the pilot scale or larger. A brief process description, a summary of the development status and performance achieved to date, pending commercialization issues, and process economics (when available) are given for each technology.

  18. Alternative flue gas treatment technologies for integrated SO{sub 2} and NO{sub x} control

    SciTech Connect

    Markussen, J.M.; Livengood, D.D.

    1995-06-01

    Enactment of the 1990 Clean Air Act Amendments, as well as passage of legislation at the state level has raised the prospect of more stringent nitrogen oxides (NO{sub x}) emission regulations and has fueled research and development efforts on a number technologies for the combined control of sulfur dioxide (SO{sub 2}) and NO{sub x}. The integrated removal of both SO{sub 2} and NO{sub x} in a single system can offer significant advantages over the use of several separate processes, including such factors as reduced system complexity, better operability, and lower costs. This paper reviews the status of a number of integrated flue gas cleanup systems that have reached a significant stage of development, focusing on post-combustion processes that have been tested or are ready for testing at the pilot scale or larger. A brief process description, a summary of the development status and performance achieved to date, pending commercialization issues, and process economics (when available) are given for each technology.

  19. The increased concentration of SO{sub 2} and threat to the largest mangrove forest of the world - the Sundarbans

    SciTech Connect

    Ahmad, J.U.; Ullah, S.S.; Carmichael, G.R.; Haque, R.

    1996-12-31

    The atmospheric concentration of SO{sub 2} was monitored in two different sites, Khulna and Savar in Bangladesh as a part of Rains Asia Atmos Module, Phase I Project. The results show that the winter concentration of SO{sub 2} in Khulna is 3 to 4 times higher than the summer concentrations, which is also higher compared to measurements at Savar which is adjacent to Dhaka city. Based on these facts and seasonal wind pattern, trans-boundary air pollution has been suggested. Khulna is in the southwestern part of Bangladesh and this area harbors the largest mangrove forest of the world, the Sundarbans. Sundari trees are the main trees of the Sundarban ecosystem. During the last few years, many of the Sundari trees, which are quite susceptible to pH stress, are dying from the top. The unusual winter increase of atmospheric sulphurdioxide has been assigned to be one of the reasons for the top dying. Other factors might be the increase of salinity and diminished flow of water.

  20. Effect of SO/sub 2/ on light modulation of plant metabolism. Progress report

    SciTech Connect

    Anderson, L.E.

    1985-01-01

    This progress report briefly notes conclusions of work done on SO/sub 2/ effect on light modulation of plant metabolism. Conclusions include: effect of light activation on kinetic parameters of fructosebisphosphatase - for this enzyme K/sub m/ decreases and V/sub max/ increases as a result of light activation; and the effect of sulfite and arsenite on light activation in 2 Pisum cultivars - the differences in sensitivity to SO/sub 2/ is directly reflected in differences in a thylakoid bound factor (LEM) to SO/sub 2/.

  1. SO{sub 2} trading program as a metaphor for a competitive electric industry

    SciTech Connect

    O`Connor, P.R.

    1996-12-31

    This very brief presentation focuses on the competitive market impacts of sulfur dioxide SO{sub 2} emissions trading. Key points of the presentation are highlighted in four tables. The main principles and results of the emissions trading program are outlined, and the implications of SO{sub 2} trading for the electric industry are listed. Parallels between SO{sub 2} trading and electric utility restructing identified include no market distortion by avoiding serious disadvantages to competitors, and avoidance of stranded costs through compliance flexibility. 4 tabs.

  2. Flue gas cleaning with ammonia reduces SO{sub 2} emission

    SciTech Connect

    Emish, G.J.; Schulte, W.; Ellison, W.

    1997-12-31

    This paper describes the technical and commercial development and basis for application in North America for wet flue gas desulfurization (FGD) of the AMASOX{reg_sign} (i.e. Ammonia Absorbs Sulfur Oxides) Process of Krupp Uhde (Germany) employing ammonia reagent. This process technology has been emerging slowly and stepwise over a twenty-year period in reaching the present stage of commercial applicability. The discussion herein considers the need for accommodating to and advantageously addressing the increasing number of applications with high and ultra-high flue-gas concentrations of SO{sub 2} at the boiler outlet accompanied by significant levels of other pollutants. Key measures in accomplishing this include use of important process innovations. This, as well, calls for the effective use, when applicable, of wet electrostatic precipitator mist-elimination means to gain low/minimum-opacity stack plume trailoff in wet scrubber use together with reduction of air toxics to low concentrations. With cost-effectiveness in electric utility service, detailed herein, superior to FGD processes commonly used to date in high-sulfur service, utilization of this technology is expanding. Important, potentially trend-setting types of powerplant applications of ammonia FGD are reviewed to identify foreseen market sectors and procurement trends that will at the same time serve to substantially broaden lowest-cost coal utilization.

  3. Interspecific variation in SO/sub 2/ flux: leaf surface versus internal flux, and components of leaf conductance. [Pisum sativum L. , Lycopersicon esculentum Mill. Flacca, Geranium carolinianum L. , Diplacus aurantiacus (Curtis) Jeps

    SciTech Connect

    Olszyk, D.M.; Tingey, D.T.

    1985-12-01

    The objective of this study was to clarify the relationships among stomatal, residual, and epidermal conductances in determining the flux of SO/sub 2/ air pollution to leaves. Variations in leaf SO/sub 2/ and H/sub 2/O vapor fluxes were determined using four plant species: Pisum sativum L. (garden pea), Lycopersicon esculentum Mill. flacca (mutant of tomato), Geranium carolinianum L. (wild geranium), and Diplacus aurantiacus (Curtis) Jeps. (a native California shrub). Fluxes were measured using the mass-balance approach during exposure to 4.56 micromoles per cubic meter (0.11 microliters per liter) SO/sub 2/ for 2 hours in a controlled environmental chamber. Flux through adaxial and abaxial leaf surfaces with closed stomata ranged from 1.9 to 9.4 nanomoles per square meter per second for SO/sub 2/, and 0.3 to 1.3 millimoles per square meter per second for H/sub 2/O vapor. Flux of SO/sub 2/ into leaves through stomata ranged from approx.0 to 8.5 (dark) and 3.8 to 16.0 (light) millimoles per square meter per second. Flux of H/sub 2/O vapor from leaves through stomata ranged from approx.0 to 0.6 (dark) to 0.4 to 0.9 (light) millimole per square meter per second. Lycopersicon had internal flux rates for both SO/sub 2/ and H/sub 2/O vapor over twice as high as for the other species. Stomatal conductance based on H/sub 2/O vapor flux averaged from 0.07 to 0.13 mole per square meter per second among the four species. Internal conductance of SO/sub 2/ as calculated from SO/sub 2/ flux was from 0.04 mole per square meter per second lower to 0.06 mole per square meter per second higher than stomatal conductance. For Pisum, Geranium, and Diplacus stomatal conductance was the same or slightly higher than internal conductance, indicating that, in general, SO/sub 2/ flux could be predicted from stomatal conductance for H/sub 2/O vapor.

  4. Sulfatization of vanadium pentoxide in equilibrium gaseous mixtures containing SO{sub 2}, SO{sub 3}, and O{sub 2}

    SciTech Connect

    Ivanenko, S.V.; Dzhoraev, R.R.

    1994-07-01

    The sulfatization of V{sub 2}O{sub 5} supported on SiO{sub 2} and SiO{sub 2} + MgSO{sub 4} carriers in equilibrium gaseous SO{sub 2}-SO{sub 3}-O{sub 2}-N{sub 2} mixtures at P{sub SO{sub 3}} = 0.8 - 33 kPa and T {>=} 673 K is studied using a flow thermogravimetric setup. Sulfatization is accompanied by V{sub 2}O{sub 5} reduction and production of vanadyle sulfate VOSO{sub 4}, which can decay completely or partially, depending on the conditions. This is supported by hysteresis observed in the course of the sulfatization and desulfatization of the catalyst. The experimental data indicates the formation of surface sulfates with various formations heats, which is determined by the energetic heterogeneity of the surface.

  5. Plant betterment for an anthracite-burning utility in Ukraine: Coal preparation as part of a SO{sub 2}, NO{sub x}, and particulate emission control strategy

    SciTech Connect

    Ruether, J.A.; Freeman, M.C.; Gollakota, S.V.

    1997-12-31

    Workers at the Energy Departments of the US and Ukraine have cooperatively devised a strategy for upgrading performance of a 200 MWe wet bottom pulverized coal boiler in eastern Ukraine at the Lugansk GRES power station. The plant currently burns poor quality anthracite (30% ash versus 18% ash design coal, as-received basis) and is in need of maintenance. Oil or gas support fuel in the amount of 30% (calorific basis) is required to stabilize the flame and supplement the calorific value of the coal feed. No NO{sub x} or SO{sub 2} controls are used at present, and unburned carbon content in the fly ash is high. An experimental program was carried out at the Federal Energy Technology Center (FETC) to estimate the improvement in plant performance that could be expected if the unit is supplied with design coal and is refurbished. High ash Ukrainian anthracite was cleaned to design specifications. Raw and cleaned coal were fed to a 490 MJ/h coal feed combustion unit at a number of conditions of support fuel use and ingress air leakage designed to simulate current and improved operations at the power plant. The results indicate the improvement in performance and reductions in SO{sub 2} and NO{sub x} emissions that can be expected as a result of the planned upgrade and conversion to use of cleaned coal. A detailed engineering and financial analysis indicates that plant rehabilitation combined with the use of cleaned schtib reduces not only pollutant emissions but also cost of electricity (COE). Additional benefits include increased plant life and capacity, and reduced supplementary fuel consumption.

  6. (Effect of SO/sub 2/ on light modulation of plant metabolism). Progress report

    SciTech Connect

    Not Available

    1981-01-01

    The membrane bound, sulfite sensitive, light effect mediator protein was identified and isolated from leaves of the pea. This protein appears to mediate the effect of SO/sub 2/ on plants. 2 refs. (DT)

  7. Additional double-wall roof in single-wall, closed, convective incubators: Impact on body heat loss from premature infants and optimal adjustment of the incubator air temperature.

    PubMed

    Delanaud, Stéphane; Decima, Pauline; Pelletier, Amandine; Libert, Jean-Pierre; Stephan-Blanchard, Erwan; Bach, Véronique; Tourneux, Pierre

    2016-09-01

    Radiant heat loss is high in low-birth-weight (LBW) neonates. Double-wall or single-wall incubators with an additional double-wall roof panel that can be removed during phototherapy are used to reduce Radiant heat loss. There are no data on how the incubators should be used when this second roof panel is removed. The aim of the study was to assess the heat exchanges in LBW neonates in a single-wall incubator with and without an additional roof panel. To determine the optimal thermoneutral incubator air temperature. Influence of the additional double-wall roof was assessed by using a thermal mannequin simulating a LBW neonate. Then, we calculated the optimal incubator air temperature from a cohort of human LBW neonate in the absence of the additional roof panel. Twenty-three LBW neonates (birth weight: 750-1800g; gestational age: 28-32 weeks) were included. With the additional roof panel, R was lower but convective and evaporative skin heat losses were greater. This difference can be overcome by increasing the incubator air temperature by 0.15-0.20°C. The benefit of an additional roof panel was cancelled out by greater body heat losses through other routes. Understanding the heat transfers between the neonate and the environment is essential for optimizing incubators.

  8. Statistical time-series analysis of emission and deposition of SO{sub 2} and NO{sub x} in northeastern North America

    SciTech Connect

    Mariam, Y.K.G.; Barre, M.

    1997-12-31

    Trend analysis and forecasting of time series data on air-pollutants is important to design effective measures to minimize damages to ecosystems and human health. In this study, autoregressive, moving average, autoregressive-moving average and autoregressive integrated moving average processes of different order were implemented to examine patterns of depositions and emissions. Analysis was undertaken to examine stationary of the series or to design a method to create stationary series. The model that satisfied selected statistical criteria was chosen to make forecasts. Forecasts of depositions were compared with critical loads by watersheds. The findings of this study indicated that both wet depositions and emissions of SO{sub 2} and NO{sub x} data exhibited non-stationary. After removing non-stationary, a suitable time-series model was selected for short-run forecasting. The resulting depositions and emissions data were examined with respect to their long-run movement and critical deposition loadings. The analysis showed that excess wet depositions of SO{sub 2} and NO{sub 3} would be major problems at least for ten years. Most of these problems are observed in Atlantic Canada and few watersheds in Quebec and Ontario. Although emissions of SO{sub 2} have declined, emissions of NO{sub x} remained unchanged or increased compared to the 1980 level. Considering the fact that these pollutants contribute to acidification, eutrophication and formation of secondary particulates that are hazardous to human health, it is necessary to find ways of further reducing emissions and depositions of these pollutants. While substantial progress has been made with respect to reduction of SO{sub 2} emissions (especially in Canada), the analysis presented in this study indicated that there must be substantially more reductions to ensure the protection of sensitive ecosystems.

  9. Crystal structure and properties of [OsO{sub 2}(NH{sub 3}){sub 4}]SO{sub 4} . H{sub 2}O

    SciTech Connect

    Burvikova, J. N. Lin'ko, I. V.; Venskovskiy, N. U.; Rybakov, V. B.

    2007-03-15

    The structure of a single crystal of tetraammindioxoosmium(VI) sulfate [OsO{sub 2}(NH{sub 3}){sub 4}]SO{sub 4} . H{sub 2}O, which is synthesized by the reaction of K{sub 2}[OsO{sub 2}(OH){sub 4}] with (NH{sub 4}){sub 2}SO{sub 4} in an aqueous solution, is investigated using X-ray diffraction analysis. The compound crystallizes in the monoclinic crystal system, space group P2{sub 1}/c, a = 13.102(2) A, b = 6.158(3) A, c = 11.866(2) A, {beta} = 98.13(2) deg., and Z = 4. The [OsO{sub 2}(NH{sub 3}){sub 4}]SO{sub 4} . H{sub 2}O compound has an island structure. Two crystallographically independent osmium atoms are situated at the centers of symmetry, and their octahedral coordination includes two oxygen atoms and four nitrogen atoms of the ammonia molecules. In both octahedra, the osmyl group is linear. The Os-O distances in the octahedra are identical within the standard deviations [Os(1)-O, 1.762(2) A; Os(2)-O, 1.769(2) A]. The Os-N bond lengths vary from 2.082(3) to 2.101(3) A. The cationic complexes, SO{sub 4} groups, and water molecules are linked via the system of hydrogen bonds. The assignment of the absorption bands in the IR spectrum of the compound synthesized is performed, and its thermal behavior in air is studied.

  10. High SO{sub 2} removal efficiency testing. Technical progress report

    SciTech Connect

    Blythe, G.

    1994-04-28

    The project involves testing at six full-scale utility flue gas desulfurization (FGD) systems, to evaluate low capital cost upgrades that may allow these systems to achieve up to 98% SO{sub 2} removal efficiency. The upgrades to be evaluated mostly involve using additives in the FGD systems. On the base program, testing was completed at the Tampa Electric Big Bend Station in November 1992. The upgrade option tested was DBA additive. For Option 1, at the Hoosier Energy Merom Station, three upgrade options have been tested: DBA additive, sodium formate additive, and high pH set point operation. Option 2 has involved testing at the Southwestern Electric Power Company Pirkey Station. Both sodium formate and DBA additives were tested as potential upgrade options at Pirkey. On Option 3, for testing at the PSI Energy Gibson Station, a DBA additive performance and consumption test was conducted in late February through mid-March 1994. Preliminary results from these tests are discussed in Section 3 of this progress report. Option 4 is for testing at the Duquesne Light Elrama Station. The FGD system employs magnesium-enhanced lime reagent and venturi absorber modules. An EPRI-funded model evaluation of potential upgrade options for this FGD system, along with a preliminary economic evaluation, determined that the most attractive upgrade options for this site were to increase thiosulfate ion concentrations in the FGD system liquor to lower oxidation percentages and increase liquid-phase sulfite alkalinity, and to increase the venturi absorber pressure drop to improve gas/liquid contacting. Parametric testing of these upgrade options was conducted in late March 1994. Preliminary results from these tests are also discussed in Section 3 of this progress report.

  11. Ambient air monitoring plan for Ciudad Acuna and Piedra Negras, Coahuila, Mexico. Final report

    SciTech Connect

    Winberry, J.; Henning, L.; Crume, R.

    1998-01-01

    The Cities of Ciudad Acuna and Piedras Negras and the State of Coahuila in Mexico are interested in improving ambient air quality monitoring capabilities in the two cities through the establishment of a network of ambient air monitors. The purpose of the network is to characterize population exposure to potentially harmful air contaminants, possibly including sulfur dioxide (SO{sub 2}), nitrogen oxides (NO{sub x}), ozone (O{sub 3}), carbon monoxide (CO), total suspended particulate matter (TSP), particulate matter with aerodynamic diameter less than 100 micrometers PM-10, and lead. This report presents the results of an evaluation of existing air quality monitoring equipment and facilities in Ciudad Acuna and Piedras Negras. Additionally, the report presents recommendations for developing an air quality monitoring network for PM-10, SO{sub 2}, lead, and ozone in these cities, using a combination of both new and existing equipment. The human resources currently available and ultimately needed to operate and maintain the network are also discussed.

  12. Boundary lubrication of formulated C-ether in air to 300 deg C. 1: Phosphorus ester additives

    NASA Technical Reports Server (NTRS)

    Jones, W. R., Jr.; Hady, W. F.

    1972-01-01

    Friction and wear measurements were made on CVM M-50 steel lubricated with three C-ether (modified polyphenyl ether) formulations in dry and wet air. Results were compared to those obtained with a formulated Type 2 ester and the C-ether base fluid. A ball-on-disk sliding friction apparatus was used. Experimental conditions were a 1-kilogram load, a 17-meter-perminute (100-rpm) surface speed, and a 25 to 300 C (77 to 572 F) disk temperature range. The C-ether base fluid and the three formulated C-ether fluids yielded lower wear than the Type 2 ester over the entire temperature range. All C-ether fluids exhibited slightly higher friction coefficients than the ester from 150 to 300 C (302 to 572 F) and similar values from 25 to 150 C (77 to 302 F). In general, lower wear rates were observed with the C-ethers when tested in wet air as compared to a dry air atmosphere.

  13. Simultaneous removal of NO and SO{sub 2} by high-temperature fluidized zero-valent iron processes

    SciTech Connect

    Shiao-Shing Chen; Chih-Yu Cheng; Chung-Cheng Wei; Chao-Heng Tseng

    2007-03-15

    A new approach to simultaneously remove nitrogen monoxide (NO) and sulfur dioxide (SO{sub 2}) by zero valent iron (ZVI) was investigated. Three different parameters, temperature, flux, and ZVI dosage, were tested in fluidized ZVI column studies containing 500 ppmv of NO and SO{sub 2}, respectively. Under the ZVI dosage of 0.5 g at flux of 0.6 L/cm{sub 2} min for temperature 573 K, there is neither NO nor SO{sub 2} reduction. For 623 K and 673 K, complete removal for NO and 90% removal for SO{sub 2} were achieved. For temperatures of 723 K and 773 K, 100% removal was achieved for both NO and SO{sub 2}. The amounts of NO or SO{sub 2} reduction increased as temperature increased, and linearities were observed with both correlation coefficients 0.97. Compared with NO, SO{sub 2} had earlier breakthrough because of a slower diffusion rate and less reactivity but higher mass reduction because of a higher molecular weight for SO{sub 2}. At the same temperature, both NO and SO{sub 2} reductions were constant regardless of either flux or ZVI dosage variation, but breakthrough time was affected by both flux and ZVI dosage. A parameter weight of ZVI/flux (W/F) was developed to represent these two parameters and assess the breakthrough time of NO and SO{sub 2}. Higher breakthrough time was achieved for higher W/F value. Longer breakthrough time and more NO and SO{sub 2} mass reduction were achieved for combined NO and SO{sub 2} than individual NO or SO{sub 2} treated by ZVI, and both oxidation and reduction reactions occurred. 15 refs., 8 figs., 1 tab.

  14. Simultaneous removal of SO{sub 2} and NO from flue gas using 'oxygen-enriched' highly reactive absorbent

    SciTech Connect

    Zhao, Y.; Sun, X.J.; Fang, H.; Liu, F.

    2007-04-15

    Fly ash, industry-grade lime, and an additive, MnO{sub 2} (M), were used to prepare an 'oxygen-enriched' highly reactive absorbent. Experiments of simultaneous desulfurization and denitrification were carried in a flue gas circulating fluidized bed (CFB). The effects of influencing factors were also investigated on the removal efficiencies of desulfurization and denitrification. Removal efficiencies of 95.5% for SO{sub 2} and 64.8% for NO were obtained respectively under the optimal experimental conditions. The component of the spent absorbent was analyzed with chemical analysis methods. The results indicated that more nitrogen species appeared in the spent absorbent except sulfur species. A scanning electron microscope (SEM) and an accessory X-ray energy spectrometer (EDS) were used to observe microproperties of the samples, including fly ash, oxidizing highly reactive absorbent, and spent absorbent. The simultaneous removal mechanism of SO{sub 2} and NO based on this absorbent was proposed according to the experimental results.

  15. SOXAL combined SO{sub x}/NO{sub x} flue gas control demonstration. Quarterly report, July--September 1993

    SciTech Connect

    1993-12-31

    AQUATECH Systems, a business unit of Allied-Signal Inc., proposes to demonstrate the technical viability and cost effectiveness of the SOXAL process a combined SO{sub x}/NO{sub x} control process on a 3 MW equivalent flue gas slip stream from Niagara Mohawk Power Corporation Dunkirk Steam Station Boiler No. 4, a coal fired boiler. The SOXAL process combines 90+% sulfur dioxide removal from the flue gas using a sodium based scrubbing solution and regeneration of the spent scrubbing liquor using AQUATECH Systems` proprietary bipolar membrane technology. This regeneration step recovers a stream of sulfur dioxide suitable for subsequent processing to salable sulfur or sulfuric acid. Additionally 90+% control of NO{sub x} gases can be achieved in combination with conventional urea/methanol injection of NO{sub 2} gas into the duct. The SOXAL process is applicable to both utility and industrial scale boilers using either high or lower sulfur coal. The SOXAL demonstration Program began September 10, 1991 and is approximately 26 months in duration. During the 6 months of scheduled operations, between January and July of 1993, data was collected from the SOXAL system to define: SO{sub 2} and NO{sub x} control efficiencies; Current efficiency for the regeneration unit; Sulfate oxidation in the absorber; Make-up reagent rates; Product quality including concentrations and compositions; System integration and control philosophy; and Membrane stability and performance with respect to foulants. The program is expected to be concluded in November 1993.

  16. Role of Additives in Composite PEI/Oxide CO₂ Adsorbents: Enhancement in the Amine Efficiency of Supported PEI by PEG in CO₂ Capture from Simulated Ambient Air.

    PubMed

    Sakwa-Novak, Miles A; Tan, Shuai; Jones, Christopher W

    2015-11-11

    Supported amines are promising candidate adsorbents for the removal of CO2 from flue gases and directly from ambient air. The incorporation of additives into polymeric amines such as poly(ethylenimine) (PEI) supported on mesoporous oxides is an effective strategy to improve the performance of the materials. Here, several practical aspects of this strategy are addressed with regards to direct air capture. The influence of three additives (CTAB, PEG200, PEG1000) was systematically explored under dry simulated air capture conditions (400 ppm of CO2, 30 °C). With SBA-15 as a model support for poly(ethylenimine) (PEI), the nature of the additive induced heterogeneities in the deposition of organic on the interior and exterior of the particles, an important consideration for future scale up to practical systems. The PEG200 additive increased the observed thermodynamic performance (∼60% increase in amine efficiency) of the adsorbents regardless of the PEI content, while the other molecules had less positive effects. A threshold PEG200/PEI value was identified at which the diffusional limitations of CO2 within the materials were nearly eliminated. The threshold PEG/PEI ratio may have physical origin in the interactions between PEI and PEG, as the optimal ratio corresponded to nearly equimolar OH/reactive (1°, 2°) amine ratios. The strategy is shown to be robust to the characteristics of the host support, as PEG200 improved the amine efficiency of PEI when supported on two varieties of mesoporous γ-alumina with PEI.

  17. Effects of gaseous NH{sub 3} and SO{sub 2} on the concentration profiles of PCDD/F in flyash under post-combustion zone conditions

    SciTech Connect

    Hajizadeh, Yaghoub; Onwudili, Jude A.; Williams, Paul T.

    2012-07-15

    Highlights: Black-Right-Pointing-Pointer Influence of NH{sub 3} and SO{sub 2} on 2378-PCDD/F in flyash and flue gases was investigated. Black-Right-Pointing-Pointer NH{sub 3} decreased the concentration of PCDD and PCDF by 34-75% in the flyash. Black-Right-Pointing-Pointer NH{sub 3} decreased the concentration of PCDD and PCDF by 21-40% from the flue gases. Black-Right-Pointing-Pointer SO{sub 2} led to 99% PCDD and 93% PCDF reductions in the flyash. Black-Right-Pointing-Pointer SO{sub 2} led to 89% PCDD and 76% PCDF reductions in the flue gases. - Abstract: The influence of gaseous ammonia and sulphur dioxide on the formation of 2378-substituted PCDD/F on a reference flyash from a municipal waste incinerator has been investigated using a laboratory scale fixed-bed reactor. The reference flyash samples (BCR-490) was reacted under a simulated flue gas stream at temperatures of 225 and 375 Degree-Sign C for 96 h. The experiments were carried out in two series: first with simulated flue gas alone, and then with injection of NH{sub 3} or SO{sub 2} gas into the flue gas just before the reactor inlet. It was found that the injection of gaseous ammonia into the flue gas could decrease the concentration of both PCDD and PCDF by 34-75% from the solid phase and by 21-40% from the gas phase. Converting the results to I-TEQ values, it could reduce the total I-TEQ values of PCDD and PCDF in the sum of the flyash and exhaust flue gas by 42-75% and 24-57% respectively. The application of SO{sub 2} led to 99% and 93% reductions in the PCDD and PCDF average congener concentrations, respectively in the solid phase. In the gas phase, the total reductions were 89% and 76% for PCDD and PCDF, respectively. Moreover, addition of SO{sub 2} reduced the total I-TEQ value of PCDD and PCDF in the flyash and exhaust flue gas together by 60-86% and 72-82% respectively. Sulphur dioxide was more effective than ammonia in suppressing PCDD/F formation in flyash under the conditions investigated.

  18. High SO{sub 2} removal efficiency testing. Technical progress report, October--December 1995

    SciTech Connect

    Blythe, G.

    1995-10-18

    This project involves testing at six full-scale utility flue gas desulfurization (FGD) systems, to evaluate low capital cost upgrades that may allow these systems to achieve up to 98% SO{sub 2} removal efficiency. The upgrades being evaluated mostly involve using performance additives in the FGD systems. The ``base`` project involved testing at the Tampa Electric Company Big Bend station. All five potential options to the base program have been exercised by DOE, involving testing at Hoosier Energy`s Merom Station (Option I), Southwestern Electric Power Company`s Pirkey Station (Option II), PSI Energy`s Gibson Station (Option III), Duquesne Light`s Elrama Station (Option IV), and New York State Electric and Gas Corporation`s Kintigh Station (Option V). The originally planned testing has been completed for all six sites. Following the introduction, this report is divided into four sections. Section 2, Project Summary, provides a brief overview of the status of technical efforts on this project. Section 3, Results, summarizes the outcome from technical efforts during the quarter, or results from prior quarter that have not been previously reported. In Section 4, Plans for the Next Reporting Period, an overview is provided of the technical efforts anticipated for the first quarter of calendar year 1996. Section 5 contains a brief acknowledgment.

  19. A numerical study on the effect of hydrogen/reformate gas addition on flame temperature and NO formation in strained methane/air diffusion flames

    SciTech Connect

    Guo, Hongsheng; Neill, W. Stuart

    2009-02-15

    This paper investigates the effects of hydrogen/reformate gas addition on flame temperature and NO formation in strained methane/air diffusion flames by numerical simulation. The results reveal that flame temperature changes due to the combined effects of adiabatic temperature, fuel Lewis number and radiation heat loss, when hydrogen/reformate gas is added to the fuel of a methane/air diffusion flame. The effect of Lewis number causes the flame temperature to increase much faster than the corresponding adiabatic equilibrium temperature when hydrogen is added, and results in a qualitatively different variation from the adiabatic equilibrium temperature as reformate gas is added. At some conditions, the addition of hydrogen results in a super-adiabatic flame temperature. The addition of hydrogen/reformate gas causes NO formation to change because of the variations in flame temperature, structure and NO formation mechanism, and the effect becomes more significant with increasing strain rate. The addition of a small amount of hydrogen or reformate gas has little effect on NO formation at low strain rates, and results in an increase in NO formation at moderate or high strain rates. However, the addition of a large amount of hydrogen increases NO formation at all strain rates, except near pure hydrogen condition. Conversely, the addition of a large amount of reformate gas results in a reduction in NO formation. (author)

  20. Effect of SO2 Addition on Air Oxidation Behavior of CM247 and CMSX-4 at 1050°C

    NASA Astrophysics Data System (ADS)

    Jalowicka, A.; Nowak, W. J.; Naumenko, D.; Quadakkers, W. J.

    2016-11-01

    In the present work, the oxidation behavior of two commercial Ni-base superalloys, CMSX-4 and CM247, in synthetic air with and without 2 vol.% SO2 at 1050°C has been studied. The corrosion reactions in the presence of SO2 could not be explained simply in terms of the contents of the main scale-forming alloying elements, Cr and Al. The far better resistance of CMSX-4 is related to the formation of a rather pure and dense alumina scale after a very short period of transient oxidation. Rapid development of an alumina scale prevents access of molecular SO2 to the metal surface thus effectively suppressing internal sulfidation. In contrast, CM247 with a similar Al-content formed an Al-rich oxide scale with local intrusions and/or inhomogeneities caused by the underlying alloy microstructure, which deteriorated its resistance to internal sulfidation and resulted in rapid failure in synthetic air + 2% SO2.

  1. Effects of air exposure, temperature and additives on fermentation characteristics, yeast count, aerobic stability and volatile organic compounds in corn silage.

    PubMed

    Weiss, K; Kroschewski, B; Auerbach, H

    2016-10-01

    Ensiling conditions strongly influence fermentation characteristics, yeast count, and aerobic stability. Numerous volatile organic compounds including esters are produced, which may negatively affect feed intake and animal performance and air quality. In addition to a farm survey, 3 laboratory experiments were carried out to study the effects of air (by delayed sealing or by air infiltration during anaerobic storage), temperature (20 and 35°C), and various types of additives [blends of either sodium benzoate and sodium propionate (SBSP) or of sodium benzoate and potassium sorbate (SBPS); buffered mixture of formic and propionic acids (FAPA); homofermentative inoculant (LAB)]. After additive treatment, chopped whole corn plants were packed into 1.5-L glass jars and stored for several months. For treatments with air infiltration, glass jars with holes in the lid and body were used. The farm survey in 2009 revealed large variation in lactate, acetate, ethanol, n-propanol, and 1,2-propanediol concentrations. Whereas ethyl esters were detected in all silages, the mean ethyl lactate concentrations were higher than those for ethyl acetate (474 vs. 38mg/kg of dry matter). In the ensiling experiments, few unequivocal effects of the tested factors on the analyzed parameters were observed due to many interactions. Delayed ensiling without additives decreased lactic acid production but, in one trial, increased acetic acid and had no effect on ethanol. The effect of delayed sealing on yeast counts and aerobic stability differed widely among experiments. Air infiltration during fermentation tested in one trial did not alter lactic acid production, but resulted in more acetic acid in delayed and more ethanol than in promptly sealed untreated silages. Greater ethanol production was associated with increased yeast numbers. Storage at high temperature resulted in lower lactic acid and n-propanol, and a trend toward reduced ethanol production was observed. The additive FAPA

  2. Lung cancer and ambient air pollution in Helsinki

    SciTech Connect

    Poenkae, A.; Pukkala, E.; Hakulinen, T.

    1993-12-31

    In a record linkage study between the population register of the City of Helsinki and the Finnish Cancer Registry, standardized incidence ratios (SIR) of lung cancer for 33 subareas of Helsinki were estimated in order to determine the regional differences and the extent to which these were the effects of socioeconomic factors and air pollution. In addition, the SIRs for people living along main streets were calculated. In 1975-86, 2,439 cases of lung cancer among males and 765 among females were diagnosed in a population of 0.5 million inhabitants. In the subareas, the SIR for males varied from 0.56 to 1.56 and for females from 0.29 to 3.17. A strong inverse association, most likely due to smoking, was observed between lung cancer and average educational level. The levels of sulfur dioxide (SO{sub 2}) and nitrogen dioxide (NO{sub 2}) in the air of various parts of the city were assessed from mathematical models. After adjustment for age, sex, and level of education, the lung cancer risk increased slightly, but nonsignificantly, with increasing SO{sub 2} concentration, being 1.3% higher in the subareas with the highest SO{sub 2} concentrations as compared with the subareas with the lowest concentrations. There was no consistent relation between the concentration of NO{sub 2} and the incidence of lung cancer. The SIR for people living along main streets was slightly lower than for the whole city, varying from 0.39 to 1.31 for males and from 0.24 to 1.51 for females. This variation was likewise mainly attributable to average educational level, but the multiple regression model also revealed slightly, although nonsignificantly, higher SIRs along the streets with denser road traffic. 51 refs., 6 figs., 2 tabs.

  3. Effects of O{sub 2} and SO{sub 2} on the Capture Capacity of a Primary-Amine Based Polymeric CO{sub 2} Sorbent

    SciTech Connect

    Hallenbeck, Alexander P; Kitchin, John R

    2013-08-01

    Post combustion CO{sub 2} capture is most commonly carried out using an amine solution that results in a high parasitic energy cost in the stripper unit due to the need to heat the water which comprises a majority of the amine solution. It is also well known that amine solvents suffer from stability issues due to amine leaching and poisoning by flue gas impurities. Solid sorbents provide an alternative to solvent systems that would potentially reduce the energy penalty of carbon capture. However, the cost of using a particular sorbent is greatly affected by the usable lifetime of the sorbent. This work investigated the stability of a primary amine-functionalized ion exchange resin in the presence of O{sub 2} and SO{sub 2}, both of which are constituents of flue gas that have been shown to cause degradation of various amines in solvent processes. The CO{sub 2} capture capacity was measured over multiple capture cycles under continuous exposure to two simulated flue gas streams, one containing 12 vol% CO{sub 2}, 4% O{sub 2}, 84% N{sub 2}, and the other containing 12.5 vol% CO{sub 2}, 4% O{sub 2}, 431 ppm SO{sub 2}, balance N{sub 2} using a custom-built packed bed reactor. The resin maintained its CO{sub 2} capture capacity of 1.31 mol/kg over 17 capture cycles in the presence of O{sub 2} without SO{sub 2}. However, the CO{sub 2} capture capacity of the resin decreased rapidly under exposure to SO{sub 2} by an amount of 1.3 mol/kg over 9 capture cycles. Elemental analysis revealed the resin adsorbed 1.0 mol/kg of SO{sub 2}. Thermal regeneration was determined to not be possible. The poisoned resin was, however, partially regenerated with exposure to 1.5M NaOH for 3 days resulting in a 43% removal of sulfur, determined through elemental analysis, and a 35% recovery of CO{sub 2} capture capacity. Evidence was also found for amine loss upon prolonged (7 days) continuous exposure to high temperatures (120 C) in air. It is concluded that desulfurization of the flue gas

  4. Effect of controlled low levels of SO/sub 2/ on grasshopper densities on a northern mixed-grass prairie

    SciTech Connect

    McNary, T.J.; Milchunas, D.G.; Leetham, J.W.; Lauenroth, W.K.; Dodd, J.L.

    1981-02-01

    A northern mixed-grass prairie was exposed to monthly median SO/sub 2/ concentrations of 73, 134, and 228 ..mu..g/m/sup 3/. Total grasshopper density and the density of Melanoplus sanguinipes (F.) were significantly (P < 0.01) reduced by SO/sub 2/ treatment on late-growing-season dates within each year of SO/sub 2/ exposure. Grasshopper density tended to decrease with increasing SO/sub 2/ concentration. Sulfur dioxide did not alter the relative proportions of M. sanguinipes in the total population. 14 references, 1 figure.

  5. Pressure distribution and aerodynamic coefficients associated with heat addition to supersonic air stream adjacent to two-dimensional supersonic wing

    NASA Technical Reports Server (NTRS)

    Pinkel, I Irving; Serafini, John S; Gregg, John L

    1952-01-01

    The modifications in the pressure distributions and the aerodynamic coefficients associated with additions of heat to the two-dimensional supersonic in viscid flow field adjacetnt to the lower surface of of a 5-percent-thickness symmetrical circular-arc wing are presented in this report. The pressure distributions are obtained by the use of graphical method which gives the two-dimensional supersonic inviscid flow field obtained with moderate heat addition. The variation is given of the lift-drag ratio and of the aerodynamic coefficients of lift, drag, and moment with free stream Mach number, angle of attack, and parameters defining extent and amount of heat addition. The six graphical solutions used in this study included Mach numbers of 3.0 and 5.0 and angles of attack of 0 degrees and 2 degrees.

  6. Comparison of open and controlled pollinated pine families for susceptibility to air pollution, acid rain, and fusiform rust. Progress report

    SciTech Connect

    Chevone, B.; Powers, H.R. Jr.

    1982-10-01

    Loblolly pine seedlings were fumigated with SO/sub 2/, ozone, and a combination of SO/sub 2/ and ozone to determine the relative susceptibility of different strains to air pollution and to fusiform rust. There seems to be no relationship between susceptibility to air pollution and to fusiform rust, indicating it should be possible to select strains resistant to both fusiform rust and air pollution. (ACR)

  7. Recent trends in SO{sub 2} allowance marketplace

    SciTech Connect

    Bartels, C.W.

    1997-12-31

    The author reviews the development of the marketplace for tradable allowances created under Title IV of the Clean Air Act Amendments (CAAA) of 1990. The major characteristics exhibited by today`s market are traced to the key factors affecting market development. The author concludes that the market has finally reached a level of early maturity, implying a more systematic approach to trading.

  8. SO/sub 2/ dose-response sensitivity classification data for crops and natural vegetation species

    SciTech Connect

    Irving, P.M.; Ballou, S.W.

    1980-09-01

    Over the past several years studies have been made on the interaction of sulfur dioxide (SO/sub 2/) and vegetation by performing field research and by developing analytical procedures for applying field observation data to energy impact assessments. As a result of this work, numerous reports have been prepared on crop-pollutant interactions, such as dose-response data; on the applications of such data to screening approaches for identifying crops at risk; and on models that predict crop yield reductions from point source emissions of SO/sub 2/. Data that were used for these studies, such as the crop-at-risk screening procedure, are presented in this report. Maps are also presented that show the national distribution of SO/sub 2/-sensitive crops and natural vegetation.

  9. SO{sub 2} oxidation in a periodically operated trickle bed: Comparison of activated carbon catalysts

    SciTech Connect

    Lee, Joong Kee; Hudgins, R.R.; Silveston, P.L.

    1996-12-31

    Catalytic activities of two different activated carbons, BPL{trademark} and Centaur{trademark} catalysts (Calgon Carbon Corp.), were compared in a periodically operated trickle-bed reactor for SO{sub 2} oxidation by varying the cycle period and split. In an effort to characterize the carbon surface, differential thermogravimetric analysis and TPD were used to observe oxygen functional groups. The Centaur catalyst, which appears to have a more suitable density of oxygen functional groups, has the higher catalytic activity for SO{sub 2} oxidation. 8 refs., 8 figs., 1 tab.

  10. Modeling the effects of changes in New Source Review on national SO{sub 2} and NOx emissions from electricity-generating units

    SciTech Connect

    David A. Evans; Benjamin F. Hobbs; Craig Oren; Karen L. Palmer

    2007-03-15

    The Clean Air Act establishes New Source Review (NSR) programs that apply to the construction or modification of major stationary emissions sources. In 2002 and 2003, the U.S. Environmental Protection Agency revised its rules to narrow the applicability of NSR to facility renovations. Congress then mandated a National Research Council study of the effects of the rules. An electricity-sector model - the Integrated Planning Model (IPM) - was used to explore the possible effects of the equipment replacement provision (ERP), the principal NSR change that was to affect the power-generation industry. The studies focused in particular on coal-fired electricity generating units, EGUs, for two reasons. First, coal-fired EGUs are important contributors of these pollutants, accounting for approximately 70 and 20% of nations SO{sub 2} and NOx emissions in 2004, respectively. Second, the shares of total capacity of large coal-fired EGUs that lack flue-gas desulfurization to control SO{sub 2} and selective catalytic reduction to reduce NOx emissions are 62 and 63% respectively. Although the analysis cannot predict effects on local emissions, assuming that the Clean Air Interstate Rule (CAIR) is implemented, we find that stringent enforcement of the previous NSR rules would likely lead to no or limited decreases in national emissions compared to policies such as ERP. Our results indicate that tighter emissions caps could achieve further decreases in national emissions more cost-effectively than NSR programs. 15 refs., 3 figs., 1 tab.

  11. Effect on SO/sub 2/ light modulation of plant metabolism. Final progress report, June 1, 1983-May 31, 1985

    SciTech Connect

    Anderson, L.E.

    1985-01-01

    The effect of sulfite and arsenite on light activation in two pisum cultivars was examined. The experiments indicate that the difference in sensitivity to SO/sub 2/ is directly reflected in sensitivity of a thylakoid bound factor to SO/sub 2/. 2 figs. (DT)

  12. A simulation of the Cerro Hudson SO[sub 2] cloud

    SciTech Connect

    Schoeberl, M.R.; Lait, L.R.; Newman, P.A.; Krueger, A.J. ); Doiron, S.D. )

    1993-02-20

    An isentropic trajectory model is used to simulate the evolution of the southern hemisphere SO[sub 2] cloud associated with the eruption of Cerro Hudson. By matching the parcel trajectories with total ozone mapping spectrometer SO[sub 2] retrievals, the principal stratospheric injection region is determined to be between 11 and 16 km in altitude. This region is characterized by weak wind shears and is located just poleward of the subtropical jet in the outer fringe of the stratospheric polar vortex. The lack of wind shear in the injection region explains the slow zonal dispersal of the SO[sub 2] cloud which was still clearly observed 19 days after the eruption. The trajectory model simulation of the SO[sub 2] cloud shows good agreement with observations for 7 days after the eruption. Using the potential vorticity and potential temperature estimates of the initial eruption cloud, the cloud position relative to the polar night jet is shown to be nearly fixed up to September 2, 1991, which was as long as the cloud was observed. This result suggests that the lower stratopsheric polar and mid-latitude regions are nearly isolated from each other during the late August period. 9 refs., 5 figs.

  13. Theoretical studies of collisional relaxation of highly excited SO{sub 2} in an Ar bath

    SciTech Connect

    Lendvay, G.; Schatz, G.C.; Harding, L.B.

    1995-12-31

    This paper describes molecular dynamics studies of collisional relaxation of highly excited SO{sub 2} in an Ar bath. Most of the calculations use a newly developed global ab initio potential surface for SO{sub 2} that correctly describes the superoxide (SOO) and ring isomers of SO{sub 2} that occur as secondary minima on the ground state potential surface at high energies (about 75% of the dissociation energy) above the C{sub 2v} minimum. Rate constants for the S + O{sub 2} and O + SO reactions are calculated to test this surface, and to examine the importance of electronically excited states in the O + SO recombination. The Ar + SO{sub 2} collisions are described by summing the ab initio potential with empirical intermolecular potentials. The resulting average vibrational energy transfer <{Delta}E> per collision is in good agreement with direct measurements (done at energies where the secondary minima are not populated) at 1000K, but the agreement is poorer at 300K. The agreement is significantly better than was obtained in a previous theoretical study, and our results indicate that the use of improved intramolecular and intermolecular potentials is crucial to obtaining the better results. The energy dependence of <{Delta}E> is found to be much stronger at energies where the secondary minima on the potential surface are accessible, however much of this effect is reproduced using a potential that has the same dissociation energy but not the secondary minima.

  14. Synergistic effects of carboxymethyl cellulose and ZnO as alkaline electrolyte additives for aluminium anodes with a view towards Al-air batteries

    NASA Astrophysics Data System (ADS)

    Liu, Jie; Wang, Dapeng; Zhang, Daquan; Gao, Lixin; Lin, Tong

    2016-12-01

    The synergistic effects of carboxymethyl cellulose (CMC) and zinc oxide (ZnO) have been investigated as alkaline electrolyte additives for the AA5052 aluminium alloy anode in aluminium-air battery by the hydrogen evolution test, the electrochemical measurements and the surface analysis method. The combination of CMC and ZnO effectively retards the self-corrosion of AA5052 alloy in 4 M NaOH solution. A complex film is formed via the interaction between CMC and Zn2+ ions on the alloy surface. The carboxyl groups adsorbed on the surface of aluminium make the protective film more stable. The cathodic reaction process is mainly suppressed significantly. AA5052 alloy electrode has a good discharge performance in the applied electrolyte containing the composite CMC/ZnO additives.

  15. FY 1994 ambient air monitoring report for McMurdo Station, Antarctica

    SciTech Connect

    Lugar, R.M.

    1994-12-01

    This report presents the results of ambient air monitoring performed during the 1994 fiscal year (FY 1994) in the vicinity of McMurdo Station, Antarctica. Routine monitoring was performed during the 1993-1994 austral summer at three locations for airborne particulate matter less than 10 micrometers (PM-10) and at two locations for carbon monoxide (CO), sulfur dioxide (SO{sub 2}), and nitrogen oxides (NO, NO{sub 2}, and NO{sub x}). Selected PM-10 filters were analyzed for arsenic, beryllium, cadmium, chromium, lead, mercury, and nickel. Additional air samples were collected at three McMurdo area locations and at Black Island for determination of the airborne concentration of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Sampling site selection, sampling procedures, and quality assurance procedures used were consistent with US Environmental Protection Agency guidance for local ambient air quality networks.

  16. Control of coal combustion SO{sub 2} and NO{sub x} emissions by in-boiler injection of CMA. Sixth quarterly project status report, 1 January 1994--31 March 1994

    SciTech Connect

    Levendis, Y.A.; Wise, D.L.; Steciak, J.; Simons, G.

    1994-06-01

    Conclusions: 1. Impregnation of pulverized coal particles by CMA and CA (and to leser extent MA) was found to increase the combustion temperature of both the volatile and the char phases. Effects of the additives on the burntime of either of the two phases could not be clearly detected. 2. The pretreatment of pulverized (75-90{mu}m) and micronized (3.5{mu}m mean) and beneficiated coals with CMA, CA or MA (at a Ca/S = 2) substantially reduced the emission of SO{sub 2}, at gas temperatures between 1250 to 1450 K, followed by a cool-down zone, in fuel-lean combustion ({phi} = 0.35-0.57). 3. The combustion of CMA-, CA-, or MA-treated pulverized coal in normal air suggested that all three sulfur caption mechanisms, mentioned in the introduction, were evident in the present experiments. 4. The results of experiments in normal air and in atmospheres containing 40% oxygen suggested that the release and subsequent sulfation of CaO and MgO aerosols may be the main mechanism for sulfur removal in the virtually ash-free micronized coal that was treated with CMA. 5. NO{sub x} emissions were increased with higher gas temperatures. Micronized coal produced 25% less NO{sub x} than pulverized coal. This could be due to its lower nitrogen content and slightly more fuel-rich conditions for the micronized coal combustion, as well as localized fuel-rich conditions surrounding the small particles as the volatiles and char burn together. 6. The emissions of NO{sub x} from CMA-treated pulverized coal were similar to those from untreated coal, whereas CMA-treated micronized coal released slightly more NO{sub x} than it did when untreated. The latter event may be caused by the added fuel oxygen associated with the effective penetration of the CMA additive.

  17. Maximizing sinter plant operating flexibility through emissions trading and air modeling

    SciTech Connect

    Schewe, G.J.; Wagner, J.A.; Heron, T.; Topf, R.; Shepker, T.O.

    1998-12-31

    This paper provides details on the dispersion modeling analysis performed to demonstrate air quality impacts associated with an emission trading scheme for a sintering operation in Youngstown, Ohio. The emission trade was proposed to allow the sinter plant to expand its current allowable sulfur dioxide (SO2) emissions while being offset with SO{sub 2} emissions from boilers at a nearby shutdown steel mill. While the emission trade itself was feasible and the emissions required for the offset were available (the boiler shutdown and their subsequent SO{sub 2} emission credits were never claimed, banked, or used elsewhere), the second criteria for determining compliance was a demonstration of minimal air quality impact. The air analysis combined the increased ambient SO{sub 2} concentrations of the relaxed sinter plant emissions with the offsetting air quality of the shutdown boilers to yield the net air quality impacts. To test this net air impact, dispersion modeling was performed treating the sinter plant SO{sub 2} emissions as positive and the shutdown boiler SO{sub 2} emissions as negative. The results of the modeling indicated that the ambient air concentrations due to the proposed emissions increase will be offset by the nearby boiler emissions to levels acceptable under EPA`s offset policy Level 2 significant impact concentrations. Therefore, the dispersion modeling demonstrated that the emission trading scheme would not result in significant air quality impacts and maximum operating flexibility was provided to the sintering facility.

  18. Combined effects of prefermentative skin maceration and oxygen addition of must on color-related phenolics, volatile composition, and sensory characteristics of Airén white wine.

    PubMed

    Cejudo-Bastante, María Jesús; Castro-Vázquez, Lucía; Hermosín-Gutiérrez, Isidro; Pérez-Coello, María Soledad

    2011-11-23

    The effects of the joint prefermentative maceration and hyperoxygenation of Airén white must and wine on the phenolic content, chromatic characteristics, volatile composition, and sensory characteristics, not previously described in combination, have been evaluated. A total of 20 phenolic and 149 volatile compounds have been identified and quantified for that purpose. As a consequence of the oxygen addition, the concentrations of hydroxycinnamic acid derivatives and flavan-3-ols decreased (above all t-GRP and (+)-catechin), leading to color stabilization, but also the concentrations of several volatile compounds with a great importance for quality aroma decreased. Prefermentative skin maceration, previously applied to the hyperoxygenation of Airén musts, provided the aforementioned color stabilization in the respective wine but also increased the content of short-chain fatty acid esters and terpenes and decreased the concentration of C(6) alcohols. That combination of prefermentative treatments (skin maceration followed by must hyperoxygenation) produced an improvement of the global impression of the final wine based on significantly better scores of tropical fruit, body, and herbaceous notes.

  19. Triple-cation mixed-halide perovskites: towards efficient, annealing-free and air-stable solar cells enabled by Pb(SCN)2 additive

    PubMed Central

    Sun, Yong; Peng, Jiajun; Chen, Yani; Yao, Yingshan; Liang, Ziqi

    2017-01-01

    Organo-metal halide perovskites have suffered undesirably from structural and thermal instabilities. Moreover, thermal annealing is often indispensable to the crystallization of perovskites and removal of residual solvents, which is unsuitable for scalable fabrication of flexible solar modules. Herein, we demonstrate the non-thermal annealing fabrication of a novel type of air-stable triple-cation mixed-halide perovskites, FA0.7MA0.2Cs0.1Pb(I5/6Br1/6)3 (FMC) by incorporation of Pb(SCN)2 additive. It is found that adding Pb(SCN)2 functions the same as thermal annealing process by not only improving the crystallinity and optical absorption of perovskites, but also hindering the formation of morphological defects and non-radiative recombination. Furthermore, such Pb(SCN)2-treated FMC unannealed films present micrometer-sized crystal grains and remarkably high moisture stability. Planar solar cells built upon these unannealed films exhibit a high PCE of 14.09% with significantly suppressed hysteresis phenomenon compared to those of thermal annealing. The corresponding room-temperature fabricated flexible solar cell shows an impressive PCE of 10.55%. This work offers a new avenue to low-temperature fabrication of air-stable, flexible and high-efficiency perovskite solar cells. PMID:28383061

  20. Triple-cation mixed-halide perovskites: towards efficient, annealing-free and air-stable solar cells enabled by Pb(SCN)2 additive.

    PubMed

    Sun, Yong; Peng, Jiajun; Chen, Yani; Yao, Yingshan; Liang, Ziqi

    2017-04-06

    Organo-metal halide perovskites have suffered undesirably from structural and thermal instabilities. Moreover, thermal annealing is often indispensable to the crystallization of perovskites and removal of residual solvents, which is unsuitable for scalable fabrication of flexible solar modules. Herein, we demonstrate the non-thermal annealing fabrication of a novel type of air-stable triple-cation mixed-halide perovskites, FA0.7MA0.2Cs0.1Pb(I5/6Br1/6)3 (FMC) by incorporation of Pb(SCN)2 additive. It is found that adding Pb(SCN)2 functions the same as thermal annealing process by not only improving the crystallinity and optical absorption of perovskites, but also hindering the formation of morphological defects and non-radiative recombination. Furthermore, such Pb(SCN)2-treated FMC unannealed films present micrometer-sized crystal grains and remarkably high moisture stability. Planar solar cells built upon these unannealed films exhibit a high PCE of 14.09% with significantly suppressed hysteresis phenomenon compared to those of thermal annealing. The corresponding room-temperature fabricated flexible solar cell shows an impressive PCE of 10.55%. This work offers a new avenue to low-temperature fabrication of air-stable, flexible and high-efficiency perovskite solar cells.

  1. Control of coal combustion SO{sub 2} and NO{sub x} emissions by in-boiler injection of CMA. Final project report, July 1, 1992--December 31, 1994

    SciTech Connect

    Levendis, Y.A.

    1995-04-01

    A study was conducted to determine the efficacy of carboxylic calcium and magnesium salts (e.g., calcium magnesium acetate or CMA, CaMg{sub 2}(CH{sub 2}COOH){sub 6}) for the simultaneous removal of SO{sub 2} and NO{sub x} in oxygen-lean atmospheres. Experiments were performed in a high-temperature furnace that simulated the post-flame environment of a coal-fired boiler by providing similar temperatures and partial pressures of SO{sub 2}, NO{sub x} CO{sub 2} and O{sub 2}. When injected into a hot environment, the salts calcined and formed highly porous {open_quotes}popcorn{close_quotes}-like cenospheres. Residual MgO and/or CaCO{sub 3} and CaO reacted heterogeneously with SO{sub 2} to form MgSO{sub 4} and/or CaCO{sub 4}. The organic components - which can be manufactured from wastes such as sewage sludge - gasified and reduced NO{sub x }to N{sub 2} efficiently if the atmosphere was moderately fuel-rich. Dry-injected CMA particles at a Ca/S ratio of 2, residence time of 1 second and bulk equivalence ratio of 1.3 removed over 90% of SO{sub 2} and NO{sub x} at gas temperatures {>=} 950{degrees}C. When the furnace isothermal zone was {<=} 950{degrees}C, Ca was essentially inert in the furnace quenching zone, while Mg continued to sorb SO{sub 2} as the gas temperature cooled at a rate of -130{degrees}C/sec. Hence, the removal of SO{sub 2} by CMA could continue for nearly the entire residence time of emissions in the exhaust stream of a power plant. Additional research is needed to improve the efficiency and reduce the cost of the relatively expensive carboxylic acid salts as dual SO{sub 2}-NO{sub x} reduction agents. For example, wet injection of the salts could be combined with less expensive hydrocarbons such as lignite or even polymers such as poly(ethylene) that could be extracted from the municipal waste stream.

  2. Associations between criteria air pollutants and asthma

    SciTech Connect

    Koren, H.S.

    1995-09-01

    The evidence that asthma is increasing in prevalence is becoming increasingly compelling. This trend has been demonstrated in the United States, the United Kingdom, New Zealand, Australia, and several other Western countries. In the US, the increase is largest in the group under 18 years of age. There is mounting evidence that certain environmental air pollutants are involved in exacerbating asthma. This is based primarily on epidemiologic studies and more recent clinical studies. The U.S. Clean Air Act of 1970 provides special consideration to the class of outdoor air pollutants referred to as criteria pollutants, including O{sub 3}, sulfur dioxide (SO{sub 2}), particulate matter (PM), NO{sub x}, CO, and Pb. Standards for these pollutants are set by the US EPA with particular concern for populations at risk. Current evidence suggests that asthmatics are more sensitive to the effects of O{sub 3}, SO{sub 2} PM, and NO{sub 2}, and are therefore at risk. High SO{sub 2} and particulate concentrations have been associated with short-term increases in morbidity and mortality in the general population during dramatic air pollution episodes in the past. Controlled exposure studies have clearly shown that asthmatics are sensitive to low levels of SO{sub 2}. Exercising asthmatics exposed to SO{sub 2} develop bronchoconstriction within minutes, even at levels of 0.25 ppm. Responses are modified by air temperature, humidity, and exercise level. Recent epidemiologic studies have suggested that exposure to Pm is strongly associated with morbidity and mortality in the general population and that hospital admissions for bronchitis and asthma were associated with PM{sub 10} levels. In controlled clinical studies, asthmatics appear to be no more reactive to aerosols than healthy subjects. Consequently, it is difficult to attribute the increased mortality observed in epidemiologic studies to specific effects demonstrated in controlled human studies. 106 refs., 1 fig., 1 tab.

  3. Catalysts for the reduction of SO{sub 2} to elemental sulfur

    SciTech Connect

    Jin, Y.; Yu, Q.Q.; Chang, S.G.

    1995-11-01

    Catalysts have been prepared for the reduction of SO{sub 2} to elemental sulfur by synthesis gas. A catalyst allows to obtain more than 97% yield of elemental sulfur with a single-stage reactor at 540{degrees}C. A lifetime test has been successfully performed. The mass balance of sulfur and carbon has been checked. The effect of H{sub 2}S, COS, and H{sub 2}O has been studied.

  4. Direct effects of energy-related air pollutants on plant sexual reproduction

    SciTech Connect

    Ragsdale, H.L.; Murdy, W.H.

    1987-12-08

    Our completed research program concentrated on the direct in vivo effects of energy-related air pollutants on plant sexual reproduction. Direct air pollution effects on plant sexual reproduction have been studied for SO{sub 2} and NO{sub 2}, two of the three major air pollutants.

  5. Hollow fiber contractors for simultaneous SO{sub x}/NO{sub x} removal

    SciTech Connect

    Bhown, A.S.; Pakala, N.R.; Riggs, T.

    1995-11-01

    Control of SO{sub x} and NO{sub x} emissions from coal-fired utility and industrial boilers is a topic of growing national and international importance. Whereas a host of commercial and semicommercial processes exist, increasingly stringent emission standards mandate that processes be low cost, highly efficient, and, ideally, produce marketable byproducts. Although a wide range of site-specific economic factors dictate the best choice of SO{sub x} and NO{sub x} control, removal of SO{sub 2} by wet limestone scrubbing and removal of NO{sub x} by selective catalytic reduction (SCR) are regarded as the best commercialized technologies for this application. A typical wet limestone plant requires approximately $100 to $120 of capital investment per kilowatt of electric power generating capacity and has power and miscellaneous operating costs in the range of 5 to 6 mils per kilowatt hour (kWh). The SCR process requires approximately $70 to $100 of capital investment per kilowatt of electric power generating capacity. Its operating costs, including ammonia consumption, is in the range of 1.8 to 2.2 mils per kWh. These costs can add approximately 20% to the final cost of generated electricity, a significant burden on rate payers.

  6. New form of calcium carbonate improves SO{sub 2} removal from boilers

    SciTech Connect

    1996-11-01

    As acid rain control regulations take effect, some utility companies are considering or have installed flue gas desulfurization (FGD) systems using lime-based sorbents. With one type of FGD system, called furnace sorbent injection (FSI), sorbents are injected directly into the combustion chamber of a coal-fired boiler. Such systems have proven effective at reducing sulfur dioxide (SO{sub 2}) emissions from some types of boilers, especially those that operate at relatively low temperatures. However, FSI systems have generally not performed well with most types of conventional boilers. A New York company has patented a new FGD sorbent called thermally active marble (TAM). TAMs tend to fracture and expose new reaction surfaces - much like ice cubes in hot water. This enables such materials to neutralize SO{sub 2} more efficiently and at much higher temperatures than limestone. In fact, TAMs have shown the ability to neutralize SO{sub 2} even when injected into the hottest portion of many conventional boilers. TAMs have also been shown to reduce nitrogen oxide (NO{sub x}) formation and improve boiler efficiency by promoting more complete carbon combustion. Pilot- and full-scale tests of TAMs in several types of boilers are described in this paper. 3 refs., 1 fig., 1 tab.

  7. Center of quantum algebra U{sub q}{sup '}(so{sub 3})

    SciTech Connect

    Havlicek, Miloslav; Posta, Severin

    2011-04-15

    We analyze the structure of the center of the quantum algebra U{sub q}{sup '}(so{sub 3}). This structure, as expected, depends substantially on the deformation parameter q. When q is not a root of unity, there exists only one Casimir element, which is the deformation of ordinary Casimir element known from so{sub 3}. The center has a structure of a ring of polynomials of one variable. When q{sup n}= 1, there are three more Casimir elements of the form of polynomials in algebra generators. U{sub q}{sup '}(so{sub 3}) can be seen as a finite dimensional module over the commutative ring of polynomials in these three Casimir elements. Knowing three-parametrical family of n-dimensional irreducible representations, we prove that the dimension of this module is n{sup 3}. All four Casimir elements are no longer algebraically independent. We present the explicit description of the central variety, that is polynomial dependence between these four Casimir elements. This dependence differs for n= 2m+ 1, n= 2(2m+ 1) and n= 4m.

  8. Effects of SO/sub 2/ on growth and yield of winter crops grown in California. Research report (Final) November 1983-February 1985

    SciTech Connect

    Thompson, C.R.

    1985-09-01

    The objective of the study was to ascertain the sensitivity of wheat and lettuce to SO/sub 2/ or ambient oxidants when plants are exposed under California winter conditions, the season when these crops are normally grown in California. The study was conducted in open top field chambers at the University of California, Riverside. Wheat was exposed to SO/sub 2/ or ambient oxidants for 118 days. Lettuce was exposed to SO/sub 2/ or ambient oxidants for 47 days. SO/sub 2/ at 183 and 393 micrograms/m/sup 3/ produced chlorotic injury on wheat leaves and increased total leaf sulfur. At 79 micrograms/m/sup 3/, SO/sub 2/ reduced wheat leaf buffering capacity. SO/sub 2/ at 393 micrograms/m/sup 3/ reduced total wheat seed weight by 31%. Lettuce showed no detrimental effect from SO/sub 2/.

  9. Catalytic reduction of SO{sub 2} with methane over molybdenum catalyst. Quarterly report, 1 December 1994--28 February 1995

    SciTech Connect

    Wiltowski, T.

    1995-12-31

    One of the primary concerns in coal utilization is the emission of sulfur compounds, especially SO{sub 2}. This project deals with catalytic reduction of SO{sub 2} with methane using molybdenum sulfide catalyst supported on different activated carbons: Darco TRS, Norit ROZ-3, and an activated carbon prepared from Illinois coal IBC-110. The work conducted during this quarter has concentrated on continuation of the synthesis of activated carbon derived from Illinois coal IBC-110, modification and improvement of the apparatus for the catalyst testing, ESCA (XPS) analysis of the catalyst (10% MoS{sub 2} on Darco TRS activated carbon), and experiments in the temperature range of 450{degree}C--600{degree}C for the S0{sub 2}:CH{sub 4} ratio equal 1:1. XPS study confirmed that Mo is present in the form of Mo+4 and S in the form of S-2. The catalytic experiments of SO{sub 2} reduction with CH{sub 4} showed that for both Darco TRS and ROZ-3 supports, S0{sub 2} conversion increases with the temperature. Also, the catalyst having 20% loading of MoS{sub 2} on Darco TRS support shows the highest S0{sub 2} conversion over 10% or 15% loadings on Darco TRS. In contrast, for the ROZ-3 support, the catalyst having a 15% loading shows the highest activity. Additionally, it was observed that conversions of S0{sub 2} at 600{degree}C for both supports are comparable to each other when catalysts with 20% loadings are used; at lower temperatures, the activities are quite different with the conversions being higher for Darco TRS support.

  10. The effect of palladium additions on the solidus/liquidus temperatures and wetting properties of Ag-CuO based air brazes

    SciTech Connect

    Darsell, Jens T.; Weil, K. Scott

    2007-01-01

    A new ceramic brazing technique referred to as reactive air brazing (RAB) has recently been developed for potential applications in high temperature devices such as gas concentrators, solid oxide fuel cells, gas turbines, and combustion engines. At present, the technique utilizing a silver-copper oxide system is of great interest. The maximum operating temperature of this system is limited by its eutectic temperature of ~945°C, although in practice the operating temperature will need to be lower. An obvious strategy that can be employed to increase the maximum operating temperature of the braze material is to add a higher melting noble alloying element. In this paper, we report the effects of palladium addition on the melting characteristics of the Ag-CuO system and on the wetting properties of the resulting braze with respect to alumina. It was found that the addition of Pd will cause an increase in the melting temperature of the Ag-CuO braze but possibly at a sacrifice of wetting properties depending on composition.

  11. Effect of SO/sub 2/ on the clearance of Listeria monocytogenes from the lungs of emphysematous hamsters

    SciTech Connect

    Trimpe, K.L.; Weiss, H.; Zwilling, B.S.

    1986-10-01

    The effect of sulfur dioxide on the clearance of Listeria monocytogenes from normal and emphysematous hamsters was assessed by measuring the number of colony forming units recovered from whole lung homogenates. Continuous exposure to SO/sub 2/ after intratracheal instillation of Listeria significantly altered the clearance of viable bacteria from the lungs of emphysematous but not normal hamsters. Pre-exposure of hamsters to SO/sub 2/ for 2 weeks prior to respiratory infection had similar effects. The emphysematous hamsters exposed to SO/sub 2/ had a lower average number of Listeria in the lungs after the first week of infection than control groups. This effect appears to result from the combined influence of the SO/sub 2/, the Listeria infection, and the emphysematous condition within the lungs.

  12. Effect of SO/sub 2/ on light modulation of plant metabolism. Progress report, June 1, 1982-May 31, 1983

    SciTech Connect

    Anderson, L.E.

    1983-01-01

    Research progress is reported on investigations into the effect of light on the activity of enzymes involved in stomatal metabolism. The effects of sulfite, arsenite, and SO/sub 2/ on this light-mediated system have been studied. (ACR)

  13. Control of coal combustion SO{sub 2} and NO{sub x} emissions by in-boiler injection of CMA. Second quarterly project status report, 1 April 1993--30 June 1993

    SciTech Connect

    Levendis, Y.A.; Wise, D.L.

    1993-09-01

    Objectives of the proposed research are two-fold: (A) To understand the mechanism and assess the effectiveness of sulfur capture by the chemical calcium magnesium acetate (CMA); and (B) To evaluate the NO{sub x} reduction capabilities of CMA by pyrolyzing the organic constituents of the chemical (the acetate) and reducing NO to stable N{sub 2}. The optimum conditions and the location of CMA introduction in the furnace will be identified. Water solutions of CMA or dry powders of CMA will be injected into hot air or gases simulating the furnace exhaust (containing CO{sub 2}, SO{sub x} NO{sub x} H{sub 2}O, O{sub 2} etc.) and the composition of gaseous and solid products of the reaction will be monitored. The processes of burning the organic acetate as well as the calcination, sintering and sulfation of the remaining solid will be studied. The effectiveness of ``homemade`` CMAs containing various amounts of calcium and magnesium will be investigated to explore the role of the two chemicals in the NO{sub x} and mainly the SO{sub 2} capture processes. CMA will be introduced in the matrix of coal particles by an ion exchange technique. Upon subsequent combustion, the SO{sub 2}-NO{sub x} emissions will be monitored and compared to those from burning untreated coal. The composition and physical structure of the ash residues will also be examined.

  14. Effects of flue gas components on the reaction of Ca(OH){sub 2} with SO{sub 2}

    SciTech Connect

    Liu, C.F.; Shih, S.M.

    2006-12-20

    A differential fixed-bed reactor was employed to study the effects of the flue gas components, H{sub 2}O, CO{sub 2}, NOx, and O{sub 2}, on the reaction between Ca(OH){sub 2} and SO{sub 2} under conditions similar to those in the bag filters of a spray-drying flue gas desulfurization (FGD) system. The presence of CO{sub 2} with SO{sub 2} in the gas phase enhanced the sulfation of Ca(OH){sub 2} only when NOx was also present. When either NOx (mainly NO) or O{sub 2} was present with SO{sub 2}, the enhancement effect was slight, but became great when both NOx and O{sub 2} were present, and was even greater when CO{sub 2} was also present. The great enhancement effect exerted by the presence of NOx/O{sub 2} resulted from the rise in the NO{sub 2} concentration, which enhanced the oxidation of HSO{sub 3}- and SO{sub 3}{sup 2-} to SO{sub 4}{sup 2-} in the water layer adsorbed on Ca(OH){sub 2} surface and the formation of deliquescent salts of calcium nitrite and nitrate. The enhancement effect due to the presence of NOx/O{sub 2} was more pronounced when the relative humidity was above that at which the salts deliquesced; the extent of sulfation was more than twice that obtained when SO{sub 2} alone was present. The presence of H{sub 2}O, CO{sub 2}, NOx, and O{sub 2} in the flue gas is beneficial to the SO{sub 2} capture in the low-temperature dry and semidry FGD processes. The presence of NOx/O{sub 2} also enhanced CO{sub 2} removal when SO{sub 2} was absent.

  15. Process for simultaneous removal of SO[sub 2] and NO[sub x] from gas streams

    DOEpatents

    Rosenberg, H.S.

    1987-02-03

    A process is described for simultaneous removal of SO[sub 2] and NO[sub x] from a gas stream that includes flowing the gas stream to a spray dryer and absorbing a portion of the SO[sub 2] content of the gas stream and a portion of the NO[sub x] content of the gas stream with ZnO by contacting the gas stream with a spray of an aqueous ZnO slurry; controlling the gas outlet temperature of the spray dryer to within the range of about a 0 to 125 F approach to the adiabatic saturation temperature; flowing the gas, unreacted ZnO and absorbed SO[sub 2] and NO[sub x] from the spray dryer to a fabric filter and collecting any solids therein and absorbing a portion of the SO[sub 2] remaining in the gas stream and a portion of the NO[sub x] remaining in the gas stream with ZnO; and controlling the ZnO content of the aqueous slurry so that sufficient unreacted ZnO is present in the solids collected in the fabric filter to react with SO[sub 2] and NO[sub x] as the gas passes through the fabric filter whereby the overall feed ratio of ZnO to SO[sub 2] plus NO[sub x] is about 1.0 to 4.0 moles of ZnO per of SO[sub 2] and about 0.5 to 2.0 moles of ZnO per mole of NO[sub x]. Particulates may be removed from the gas stream prior to treatment in the spray dryer. The process further allows regeneration of ZnO that has reacted to absorb SO[sub 2] and NO[sub x] from the gas stream and acid recovery. 4 figs.

  16. Process for simultaneous removal of SO.sub.2 and NO.sub.x from gas streams

    DOEpatents

    Rosenberg, Harvey S.

    1987-01-01

    A process for simultaneous removal of SO.sub.2 and NO.sub.x from a gas stream that includes flowing the gas stream to a spray dryer and absorbing a portion of the SO.sub.2 content of the gas stream and a portion of the NO.sub.x content of the gas stream with ZnO by contacting the gas stream with a spray of an aqueous ZnO slurry; controlling the gas outlet temperature of the spray dryer to within the range of about a 0.degree. to 125.degree. F. approach to the adiabatic saturation temperature; flowing the gas, unreacted ZnO and absorbed SO.sub.2 and NO.sub.x from the spray dryer to a fabric filter and collecting any solids therein and absorbing a portion of the SO.sub.2 remaining in the gas stream and a portion of the NO.sub.x remaining in the gas stream with ZnO; and controlling the ZnO content of the aqueous slurry so that sufficient unreacted ZnO is present in the solids collected in the fabric filter to react with SO.sub.2 and NO.sub.x as the gas passes through the fabric filter whereby the overall feed ratio of ZnO to SO.sub.2 plus NO.sub.x is about 1.0 to 4.0 moles of ZnO per of SO.sub.2 and about 0.5 to 2.0 moles of ZnO per mole of NO.sub.x. Particulates may be removed from the gas stream prior to treatment in the spray dryer. The process further allows regeneration of ZnO that has reacted to absorb SO.sub.2 and NO.sub.x from the gas stream and acid recovery.

  17. Control of coal combustion SO[sub 2] and NO[sub x] emissions by in-boiler injection of CMA

    SciTech Connect

    Levendis, Y.A.; Wise, D.L.

    1992-01-01

    The principal objectives of the proposed research are two-fold: (A) To understand the mechanism and assess the effectiveness of sulfur capture by the chemical calcium magnesium acetate (CMA). And (B) To evaluate the NO[sub x] reduction capabilities of CMA by burning the organic constituents of the chemical (the acetate) and reducing NO to stable N[sub 2] The optimum conditions and the location of CMA introduction in the furnace will be identified. To achieve these goals water solutions of CMA or dry powders of CMA will be injected into hot air or gases simulating the furnace exhaust (containing CO[sub 2], SO[sub x] NO[sub x], H[sub 2]O, O[sub 2] etc.) and the composition of gaseous and solid products of the reaction will be monitored. The processes of burning the organic acetate as well as the calcination, sintering and sulfation of the remaining solid will be studied in detail.

  18. Response of pinto bean plants exposed to O/sub 3/, SO/sub 2/, or mixtures at varying temperatures

    SciTech Connect

    Miller, C.A.; Davis, D.D.

    1981-08-01

    Pinto bean plants (Phaseolus vulgaris L. ev. Pinto 111) in the uniforliolate leaf stage were exposed for 3 hours to 0.8 ppm SO/sub 2/, 0.25 ppm O/sub 3/ or a mixture of the 2 pollutants at these concentrations at 15, 24, or 32/sup 0/C. Foliage exposed to O/sub 3/ alone developed adaxial stipple and leaves exposed to SO/sub 2/ alone developed interveinal necrosis. The mixture of O/sub 3/ and SO/sub 2/ induce O/sub 3/-type symptoms at 32/sup 0/ and SO/sub 2/-type symptoms at 15/sup 0/. Both symptom types were present at 24/sup 0/. Some abaxial glazing or silvering was also induced by the mixture, and was most common at 15/sup 0/ and 24/sup 0/. Ozone and SO/sub 2/ each induced greater foliar injury at 15/sup 0/ or 32/sup 0/, as compared to 24/sup 0/. The mixture of O/sub 3/ and SO/sub 2/ induced greatest macroscopic foliar injury at 15/sup 0/. The degree of adaxial vs abaxial leaf surface injury varied with temperature.

  19. Control of coal combustion SO{sub 2} and NO{sub x} emissions by in-boiler injection of CMA. [Third quarterly progress report], 1 July 1994--30 September 1994

    SciTech Connect

    Levendis, Y.A.; Wise, D.L.; Steciak, J.

    1994-11-01

    The principal objectives of this research are two-fold: (A) To understand the mechanism and assess the effectiveness of sulfur capture by the chemical calcium magnesium acetate (CMA); and (B) To evaluate the NO{sub x} reduction capabilities of CMA by pyrolyzing the organic constituents of the chemical (the acetate) and reducing NO to stable N{sub 2}. The optimum conditions and the location of CMA introduction in the furnace will be identified. To achieve these goals water solutions of CMA or dry powders of CMA were injected into hot air or gases simulating the furnace exhaust (containing SO{sub x}, NO{sub x} H{sub 2}O, O{sub 2} etc.) and the composition of gaseous and solid products of the reaction was monitored. The processes of burning the organic acetate as well as the calcination, sintering and sulfation of the remaining solid are studied. The effectiveness of ``homemade`` CMAs containing various amounts of calcium and magnesium was investigated to explore the role of the two chemicals in the NO{sub x} and mainly the SO{sub 2} capture processes. Finally, CMA was introduced in the matrix of coal particles by an ion exchange technique. Upon subsequent combustion, the SO{sub 2}-NO{sub x} emissions were monitored and compared to those from burning untreated coal. The composition and physical structure of the ash residues was examined. Both techniques (CMA pretreatment and CMA injection) may commercially be implemented separate or simultaneously. The work reported herein pertains to introducing dry CMA and other carboxylic salts of calcium: calcium formate (CF), calcium acetate (CA), calcium propanate (CP) and calcium benzoate (CB) in the post-flame region of the furnace and monitoring the SO{sub 2} and NO{sub x}, emissions.

  20. Control of coal combustion SO{sub 2} and NO{sub x} emissions by in-boiler injection of CMA. Seventh quarterly project status report, April 1, 1994--June 30, 1994

    SciTech Connect

    Levendis, Y.A.; Wise, D.L.

    1995-02-01

    The principal objectives of this research are two-fold: (A) To understand the mechanism and assess the effectiveness of sulfur capture by the chemical calcium magnesium acetate (CMA); and (B) To evaluate the NO{sub x} reduction capabilities of CMA by pyrolyzing the organic constituents of the chemical (the acetate) and reducing NO to stable N{sub 2}. The optimum conditions and the location of CMA introduction in the furnace will be identified. To achieve these goals water solutions of CMA or dry powders of CMA were injected into hot air or gases simulating the furnace exhaust (containing SO{sub x}, NO{sub x}, H{sub 2}O, O{sub 2} etc.) and the composition of gaseous and solid products of the reaction was monitored. The processes of burning the organic acetate as well as the calcination, sintering and sulfation of the remaining solid are studied. The effectiveness of {open_quotes}homemade{close_quotes} CMAs containing various amounts of calcium and magnesium was investigated to explore the role of the two chemicals in the NO{sub x} and mainly the SO{sub 2} capture processes. Finally, CMA was introduced in the matrix of coal particles by an ion exchange technique. Upon subsequent combustion, the SO{sub 2}-NO{sub x} emissions were monitored and compared to those from burning untreated coal. The composition and physical structure of the ash residues was examined. Both techniques (CMA pretreatment and CMA injection) may commercially be implemented separate or simultaneously. The work reported herein pertains to introducing dry or wet CMA in the post-flame region of the furnace and monitoring the SO{sub 2} and NO{sub x} emissions.

  1. Microbial reduction of SO{sub 2} and NO{sub x} as a means of by-product recovery/disposal from regenerable processes for the desulfurization of flue gas. Technical progress report, September 11, 1992--December 11, 1992

    SciTech Connect

    Sublette, K.L.

    1992-12-31

    With the continual increase in the utilization of high sulfur and high nitrogen containing fossil fuels, the release of airborne pollutants into the environment has become a critical problem. The fuel sulfur is converted to SO{sub 2} during combustion. Fuel nitrogen and a fraction of the nitrogen from the combustion air are converted to nitric oxide and nitrogen dioxide, NO{sub x}. For the past five years Combustion Engineering (now Asea Brown Boveri or ABB) and, since 1986, the University of Tulsa (TU) have been investigating the oxidation of H{sub 2}S by the facultatively anaerobic and autotrophic bacterium Thiobacillus denitrificans and have developed a process, concept for the microbial removal of H{sub 2}S from a gas stream the simultaneous removal of SO{sub 2} and NO by D. desulfuricans and T. denitrificans co-cultures and cultures-in-series was demonstrated. These systems could not be sustained due to NO inhibition of D. desulfuricans. However, a preliminary economic analysis has shown that microbial reduction of SO{sub 2} to H{sub 2}S with subsequent conversion to elemental sulfur by the Claus process is both technically and economically feasible if a less expensive carbon and/or energy source can be found. It has also been demonstrated that T. denitrificans can be grown anaerobically on NO(g) as a terminal electron acceptor with reduction to elemental nitrogen. Microbial reduction of NO{sub x} is a viable process concept for the disposal of concentrated streams of NO{sub x} as may be produced by certain regenerable processes for the removal of SO{sub 2} and NO{sub x} from flue gas.

  2. Effect of relative humidity and additives on the reaction of sulfur dioxide with calcium hydroxide. Final report, January 1984-June 1986

    SciTech Connect

    Ruiz-Alsop, R.; Rochelle, G.T.

    1988-07-01

    This paper gives results of a study of the reaction of SO/sub 2/ with Ca(OH)/sub 2/ at conditions similar to those of commercial-scale bag filters: 19-74% relative humidity (RH), 30.4-95 C, and 300-4000 ppm SO/sub 2/. The study was carried out in a bench-scale reactor with powder reagent Ca(OH)/sub 2/ dispersed in silica sand. The gas phase was a mixture of N/sub 2/, SO/sub 2/, and water vapor. The effects of Ca(OH)/sub 2/ leading, temperature, RH, inlet SO/sub 2/ concentration, and additives were investigated. Of the additives tried (buffer acids, and organic and inorganic deliquescents), only the deliquescent salts improved Ca(OH)/sub 2/ reactivity toward SO/sub 2/. The improvement depends on the type and amount of salt and on the RH. The experimental data were modeled by a shrinking core model with zero-order kinetics in SO/sub 2/, using an empirical correlation to account for shape and surface roughness of the Ca(OH)/sub 2/ particles. The diffusion coefficient of the SO/sub 2/ through the product layer (De) increases linearly with RH and the amount of additive, and the kinetic rate constant (ks) increases exponentially with RH and the amount of additive.

  3. Extractive spectrophotometric determination of trace amounts of sulfur dioxide in air

    SciTech Connect

    Kumar, B.S.M.; Balasubramanian, N.

    1992-11-01

    A sensitive spectrophotometric method was developed for the determination of trace amounts of sulfur dioxide (SO{sub 2}) in air after SO{sub 2} has been fixed in a buffered formaldehyde solution. The reaction of iodate with the fixed SO{sub 2} in the presence of an acid an an excess of chloride leads to the formation of ICI{sub 2} ions. The resulting ICI{sub 2} species forms an ion-pair with pararosaniline cation; the product is extracted into isopentyl alcohol and measured spectrophotometrically at 560 nm. The color system obeys Beer`s law over the range 0-40 {mu}g SO{sub 2}. The color is stable for 72 h from the time of extraction. The molar absorption coefficient of the color system is 4.5 {times} 10{sup 3}Lmol{sup {minus}1}cm{sup {minus}1}. The coefficient of variation is 3.6% for 10 determinations at 20 {mu}g SO{sub 2}. The effect of interfering gases on the determination is discussed. The method was applied to the determination of SO{sub 2} at low concentrations, and the results obtained were compared with the widely used West and Gaeke method. The method can be used to determine as low as 2 {mu}g SO{sub 2}. 12 refs., 2 figs., 2 tabs.

  4. Process for the combined removal of SO.sub.2 and NO.sub.x from flue gas

    DOEpatents

    Chang, Shih-Ger; Liu, David K.; Griffiths, Elizabeth A.; Littlejohn, David

    1988-01-01

    The present invention in one aspect relates to a process for the simultaneous removal of NO.sub.x and SO.sub.2 from a fluid stream comprising mixtures thereof and in another aspect relates to the separation, use and/or regeneration of various chemicals contaminated or spent in the process and which includes the steps of: (A) contacting the fluid stream at a temperature of between about 105.degree. and 180.degree. C. with a liquid aqueous slurry or solution comprising an effective amount of an iron chelate of an amino acid moiety having at least one --SH group; (B) separating the fluid stream from the particulates formed in step (A) comprising the chelate of the amino acid moiety and fly ash; (C) washing and separating the particulates of step (B) with an aqueous solution having a pH value of between about 5 to 8; (D) subsequently washing and separating the particulates of step (C) with a strongly acidic aqueous solution having a pH value of between about 1 to 3; (E) washing and separating the particulates of step (D) with an basic aqueous solution having a pH value of between about 9 to 12; (F) optionally adding additional amino acid moiety, iron (II) and alkali to the aqueous liquid from step (D) to produce an aqueous solution or slurry similar to that in step (A) having a pH value of between about 4 to 12; and (G) recycling the aqueous slurry of step (F) to the contacting zone of step (A). Steps (D) and (E) can be carried out in the reverse sequence, however the preferred order is (D) and then (E). In another preferred embodiment the present invention provides a process for the removal of NO.sub.x, SO.sub.2 and particulates from a fluid stream which includes the steps of (A) injecting into a reaction zone an aqueous solution itself comprising (i) an amino acid moiety selected from those described above; (ii) iron (II) ion; and (iii) an alkali, wherein the aqueous solution has a pH of between about 4 and 11; followed by solids separation and washing as is

  5. Positive pulsed corona discharge process for simultaneous removal of SO{sub 2} and NO{sub x} from iron-ore sintering flue gas

    SciTech Connect

    Mok, Y.S.; Nam, I.S.

    1999-08-01

    The authors investigated the application of pulsed corona discharge process to the removal of SO{sub 2} and NO{sub x} from industrial flue gas of an ioron-ore sintering plant. This study was performed on a pilot scale, which is the most advanced demonstration of this process. The flow rate of 5000 m{sup 3}/h of the flue gas was successfully treated. The electrode structure of the corona reactor is the same with that of conventional electrostatic precipitator. The authors made use of magnetic pulse compression technology to produce repetitive high voltage pulse. Pulse width (full width at half maximum) was reduced to less than 1 {micro}s by connecting a resister in parallel with the corona reactor. An inductor was added to the resister in series to minimize the loss by restricting the current flowing through the resister. By this way, they were able to deliver pulse power with peak voltage of 110 kV and peak current of 2.3 kA to the corona reactor. Chemical additives such as ammonia (NH{sub 3}) and propylene (C{sub 3}H{sub 6}) were used to increase the removal efficiencies of SO{sub 2} and NO{sub x}.

  6. Catalytic reduction of SO{sub 2} with methane over molybdenum catalyst. Technical report, March 1--May 31, 1995

    SciTech Connect

    Wiltowski, T.

    1995-12-31

    One of the primary concerns in coal utilization is the emission of sulfur compounds, especially SO{sub 2}. This project deals with catalytic reduction of SO{sub 2} with methane using molybdenum sulfide catalyst supported on different activated carbons: Darco TRS, ROZ-3, and an activated carbon prepared from Illinois coal IBC-110. The work conducted during this quarter included preparation of activated carbons from Illinois coal, preparation of the catalysts on these supports, and experiments on SO{sub 2} reduction with methane at different feed ratio SO{sub 2}: CH{sub 4}. It was found that at the feed ratio 1:1, 10% MoS{sub 2} supported on Darco TRS catalyst has highest activity at low temperatures; at higher temperatures, the catalysts 15% and 20% MoS{sub 2} supported on Darco TRS exhibit high activity in both SO{sub 2} conversion (> 90%) and yield of elemental sulfur (97.4% for 20% MoS{sub 2} at 600 C). For catalyst supported on ROZ-3, this having 10% of MOS{sub 2} showed high activity in the reaction. To determine the effect of feed ratio on the reaction, the catalysts with 15% loading of MoS{sub 2} supported on Darco TRS and ROZ-3 were used. For catalyst supported on ROZ-3 activated carbon, the effect of feed ratio is dramatic, especially at the higher temperatures at which the conversion of SO{sub 2} increases more than twice when the feed contains excess of methane. For catalyst supported on Darco TRS activated carbons, there is practically no difference in SO{sub 2} conversion for feed ratios 1:1 and 1:2 (with respect for methane).

  7. Combined SO{sub 2} and NO{sub x} scrubbing process

    SciTech Connect

    Breault, R.W.; Bittenson, S.; Lani, B.

    1998-04-01

    A new wet scrubber process has been developed and undergone preliminary testing to verify the viability of a zero discharge system for SO{sub 2} and NO{sub x} removal. The process combines the Dravo ThioClear{reg_sign} process with Tecogen`s TecoLytic{trademark} process. The integration of these two technologies results a system that removes both SO{sub 2} and NO{sub x} while producing only salable byproducts. These by-products are wall board grade gypsum, magnesium hydroxide and up to 60 weight percent fertilizer grade calcium nitrate solution. Hence, a zero waste, zero discharge wet scrubber system is being demonstrated. The core of the integrated technology consists of two parts. The first part is the ThioClear process. In this process, a highly alkaline magnesium sulfite solution is used to capture the SO{sub 2} in a high velocity (greater than 15 ft/s with a nominal design of 25 ft/s) horizontal scrubber. Once captured, the sulfites are oxidized to sulfates in an oxidizing vessel. The effluent from the oxidizer is reacted with a magnesium-enhanced lime slurry to raise the pH to about 10.5. At this higher pH, 6 to Mg magnesium hydroxide precipitates and 80g or larger gypsum precipitates are formed. Subsequent product purification produces salable gypsum and magnesium hydroxide. The flue gas continues through the high velocity horizontal scrubber passing through the TecoLytic {trademark} section. In this section, high voltage is applied to produce highly reactive excited species. These species interact with the water vapor present to produce hydroxyl radicals while simultaneously oxidizing the NO to NO{sub 2}. The hydroxyl radicals rapidly oxidize the NO{sub 2} to nitric acid which is scrubbed in the second stage of the horizontal scrubber with a calcium nitrate - lime solution.

  8. Developments in SO{sub 3} decomposition for nuclear hydrogen production

    SciTech Connect

    Suppiah, Sam; Tan, G.; Deschenes, L.

    2007-07-01

    The Sulphur-Iodine (S-I) Cycle is considered to be one of the best thermochemical hydrogen production processes currently under development in many countries. While the Very High Temperature Reactors (VHTRs) are capable of satisfying the high temperature requirements of all the steps of this process, Canada's Supercritical Water Reactor (SCWR) can satisfy the temperature requirements of all but the catalytic SO{sub 3} decomposition step. However, AECL's direct electrically heated catalytic structures may be used for the decomposition with only a marginal lowering of the overall efficiency of the S-I process. An externally heated reactor system with a 25-mm diameter by 100-mm long section for catalyst loading has been set-up and a few blank tests (without any catalyst) have been conducted. Pt-TiO{sub 2} and Fe{sub 2}O{sub 3} catalysts on ceramic rings were tested to provide base-case results for comparison with catalysts to be tested with electro-resistive heating. The H{sub 2}SO{sub 4} thermal decomposition was carried out at around 475 deg. C and SO{sub 3} decomposition rates were determined over the range of 500 to 900 deg. C. While both catalysts were very active for the decomposition reaction at the higher end of the range, the Pt-TiO{sub 2} catalyst was active even at the 500 deg. C region with the Fe{sub 2}O{sub 3} catalyst being active only above 600 deg. C. (authors)

  9. DETECTING PLANETARY GEOCHEMICAL CYCLES ON EXOPLANETS: ATMOSPHERIC SIGNATURES AND THE CASE OF SO{sub 2}

    SciTech Connect

    Kaltenegger, L.; Sasselov, D.

    2010-01-10

    We study the spectrum of a planetary atmosphere to derive detectable features in low resolution of different global geochemical cycles on exoplanets-using the sulfur cycle as our example. We derive low-resolution detectable features for first generation space- and ground-based telescopes as a first step in comparative planetology. We assume that the surfaces and atmospheres of terrestrial exoplanets (Earth-like and super-Earths) will most often be dominated by a specific geochemical cycle. Here we concentrate on the sulfur cycle driven by outgassing of SO{sub 2} and H{sub 2}S followed by their transformation to other sulfur-bearing species, which is clearly distinguishable from the carbon cycle, which is driven by outgassing of CO{sub 2}. Due to increased volcanism, the sulfur cycle is potentially the dominant global geochemical cycle on dry super-Earths with active tectonics. We calculate planetary emission, reflection, and transmission spectrum from 0.4 mum to 40 mum with high and low resolution to assess detectable features using current and Archean Earth models with varying SO{sub 2} and H{sub 2}S concentrations to explore reducing and oxidizing habitable environments on rocky planets. We find specific spectral signatures that are observable with low resolution in a planetary atmosphere with high SO{sub 2} and H{sub 2}S concentration. Therefore, first generation space- and ground-based telescopes can test our understanding of geochemical cycles on rocky planets and potentially distinguish planetary environments dominated by the carbon and sulfur cycles.

  10. Surface interactions of SO{sub 2} and passivation chemistry during etching of Si and SiO{sub 2} in SF{sub 6}/O{sub 2} plasmas

    SciTech Connect

    Stillahn, Joshua M.; Zhang Jianming; Fisher, Ellen R.

    2011-01-15

    A variety of materials can be etched in SF{sub 6}/O{sub 2} plasmas. Here, the fate of SO{sub 2} at Si and SiO{sub 2} surfaces during etching in SF{sub 6}/O{sub 2} plasmas has been explored using the imaging of radicals interacting with surfaces method. The scattering of SO{sub 2} at Si and SiO{sub 2} surfaces was measured as a function of both the applied rf power and O{sub 2} addition to the plasma. For both surfaces, the surface scattering coefficient (S) of SO{sub 2} during etching is near unity and is largely unaffected by changing plasma parameters such as power and O{sub 2} addition. Notably the etch rate of Si increases monotonically with power, whereas the etch rate of SiO{sub 2} appears insensitive to changes in plasma conditions. As a result, the etch selectivity closely follows the trends of the Si etch rate. Etch rates are compared to other fluorine-containing plasma systems such as NF{sub 3}/O{sub 2} and C{sub 2}F{sub 6}/O{sub 2}. Using mass spectral data and optical emission spectra to characterize the gas phase species combined with compositional analysis from x-ray photoelectron spectroscopy data, the formation and roles of SO{sub 2} in Si and SiO{sub 2} etching are discussed and correlated with etch rate and other gas phase species such as F, O, and S{sub x}O{sub y}F{sub z}.

  11. Effect of relative humidity and additives on the reaction of sulfur dioxide with calcium hydroxide

    SciTech Connect

    Ruiz-Alsop, R.N.

    1986-01-01

    The objective of this research was to investigate the effect of process variables and additives on the reaction rate of Ca(OH)/sub 2/ with SO/sub 2/ at conditions similar to these encountered in the bag filters used to collect solids following flue gas desulfurization by spray drying. The effect of Ca(OH)/sub 2/ loading, temperature, relative humidity, and inlet SO/sub 2/ concentration were investigated. Of these variables, relative humidity showed the greatest impact on the reaction rate. The effect of small amounts of additives were also investigated. Of the additives tried (buffer acids, organic deliquescents, and inorganic deliquescents) deliquescent salts were the only additives that improved reactivity. A shrinking core model with zero order kinetics in SO/sub 2/ was used to model experimental data. An empirical correlation was included in the model to account for shape and surface roughness of the Ca(OH)/sub 2/ particles. The diffusion coefficient of the SO/sub 2/ through the product layer was found to increase linearly with relative humidity, and the kinetic rate constant increases exponentially with relative humidity. With a few exceptions the model was able to predict the experimental data within the margin of experimental error (+/- 10%). At high relative humidity and/or high SO/sub 2/ concentration, reaction kinetics control the overall reaction rate, while at low relative humidity and/or low SO/sub 2/ concentration, SO/sub 2/ diffusion through the product layer controls the rate. The reaction solids were characterized by scanning electron microscopy, powder x-ray diffraction, Coulter counter size distribution BET (N/sub 2/) surface area, energy dispersive spectrometry, and differential scanning calorimetry.

  12. Dissociative attachment of electrons to vibronically excited SO{sub 2}

    SciTech Connect

    Kumar, S.V.K.; Ashoka, V.S.; Krishnakumar, E.

    2004-11-01

    Dissociative electron attachment (DEA) to vibronically excited SO{sub 2} in the Clements' band in the 288 to 298 nm region has been studied. The O{sup -} ion yield, to a first approximation, follows the photo absorption spectrum in this range indicating the DEA process to be independent of the vibrational levels in this band. This is in contrast to what is generally observed for vibrational level dependence from the electronic ground state. The current measurements also do not show any qualitative change in the dissociative attachment process due to change of symmetry as one moves from the peaks to the valleys of the Clements band.

  13. Direct effects of energy-related air pollutants on plant sexual reproduction. Final report, February 1, 1979--January 31, 1982

    SciTech Connect

    Ragsdale, H.L.; Murdy, W.H.

    1987-12-08

    Our completed research program concentrated on the direct in vivo effects of energy-related air pollutants on plant sexual reproduction. Direct air pollution effects on plant sexual reproduction have been studied for SO{sub 2} and NO{sub 2}, two of the three major air pollutants.

  14. OH-radical specific addition to the antioxidant glutathione S-atom at the air-water interface - Relevance to the redox balance of the lung epithelial lining fluid and the causality of adverse health effects induced by air pollution

    NASA Astrophysics Data System (ADS)

    Colussi, A. J.; Enami, S.; Hoffmann, M. R.

    2015-12-01

    Inhalation of oxidant pollutants upsets the redox balance (RB) of the lung epithelial lining fluid (ELF) by triggering the formation of reactive OH-radicals therein. RB is deemed to be controlled by the equilibrium between the most abundant ELF protective antioxidant glutathione (GSH) and its putative disulfide GSSG oxidation product. The actual species produced from the oxidation of GSH initiated by ·OH in ELF interfacial layers exposed to air, i.e., under realistic ELF conditions, however, were never identified. Here we report the online electrospray mass spectrometric detection of sulfenate (GSO-), sulfinate (GSO2-) and sulfonate (GSO3-) on the surface of aqueous GSH solutions collided with ·OH(g). We show that these products arise from ·OH specific additions to S-atoms, rather than via H-abstraction from GS-H. The remarkable specificity of ·OH in interfacial water vis-a-vis its lack of selectivity in bulk water implicates an unprecedented steering process during ·OH-GSH encounters at water interfaces. A non-specific systemic immune response to inhaled oxidants should be expected if they were initially converted into a common ·OH intermediate on the ELF (e.g., via fast Fenton chemistry) and oxidative stress signaled by the [GSH]/[GSOH] ratio.

  15. The Effect of Palladium Additions on the Solidus/Liquidus Temperatures and Wetting Properties of Ag-CuO Based Air Brazes

    SciTech Connect

    Darsell, Jens T.; Weil, K. Scott

    2007-05-16

    As a means of increasing the use temperature of ceramic-ceramic and ceramic-metal air brazes, palladium was investigated as possible ternary addition to the currently employed silver - copper oxide system. The silver component was directly substituted with palladium to form the following series of alloys: (100-y)[(100-z)Pd - (z)Ag] - (y)CuOx where y = 0 - 34 mol% CuOx, z = 50 - 100 mol% silver, and x = 0, 0.5, and 1, denoting copper metal, Cu2O, or CuO. From differential scanning calorimetry, it was determined that the addition of palladium causes an increase in the solidus and liquidus temperatures of the resulting Pd-Ag-CuO brazes. In general, the liquidus was found to increase by approximately 220°C for the (100-y)(25Pd - 75Ag) - (z)CuOx filler metal compositions relative to comparable Ag-CuOx alloys. Likewise, the solidus was found to increase for these alloys, respectively by 185°C and 60°C, respectively for CuOx contents of y = 0 - 1mol% and 4 - 10 mol%. For the (100-y)(50Pd - 50Ag) - (y)CuOx alloys, the solidus increased between 280 - 390°C over a copper oxide compositional range of x = 0 to 8 mol%. It was determined from sessile drop experiments conducted on alumina substrates that in all cases the palladium causes an increase in the wetting angle relative to the corresponding binary braze. Alloy compositions of (100-y)(25Pd - 75Ag) - (y)CuOx displayed increased wetting angles of 5-20° relative to comparable binary compositions. (100-y)(50Pd - 50Ag) - (y)CuOx alloys exhibited an increase in contact angle of 10-60° and compositions containing less than 10 mol% CuOx were not able to wet the substrate. Scanning electron microscopy indicated that the microstructure of the braze consists of discrete CuOx precipitates in an alloyed silver-palladium matrix. In both the binary and ternary filler metal formulations, a reaction layer consisting of CuAlO2 was observed along the interface with the alumina substrate. This reaction product appears to be beneficial

  16. Neural network modeling of the kinetics of SO{sub 2} removal by fly ash-based sorbent

    SciTech Connect

    Raymond-Ooi, E.H.; Lee, K.T.; Mohamed, A.R.; Chu, K.H.

    2006-02-15

    The mechanistic modeling of the sulfation reaction between fly ash-based sorbent and SO 2 is a challenging task due to a variety reasons including the complexity of the reaction itself and the inability to measure some of the key parameters of the reaction. In this work, the possibility of modeling the sulfation reaction kinetics using a purely data-driven neural network was investigated. Experiments on SO{sub 2} removal by a sorbent prepared from coal fly ash/CaO/CaSO{sub 4} were conducted using a fixed bed reactor to generate a database to train and validate the neural network model. Extensive SO{sub 2} removal data points were obtained by varying three process variables, namely, SO{sub 2} inlet concentration (500-2000 mg/L), reaction temperature (60-80{sup o}C), and relative humidity (50-70%), as a function of reaction time (0-60 min). Modeling results show that the neural network can provide excellent fits to the SO{sub 2} removal data after considerable training and can be successfully used to predict the extent of SO{sub 2} removal as a function of time even when the process variables are outside the training domain. From a modeling standpoint, the suitably trained and validated neural network with excellent interpolation and extrapolation properties could have immediate practical benefits in the absence of a theoretical model.

  17. Application of calcium chloride as an additive for secondary refrigerant in the air conditioning system type chiller to minimized energy consumption

    NASA Astrophysics Data System (ADS)

    Suwono, A.; Indartono, Y. S.; Irsyad, M.; Al-Afkar, I. C.

    2015-09-01

    One way to resolve the energy problem is to increase the efficiency of energy use. Air conditioning system is one of the equipment that needs to be considered, because it is the biggest energy user in commercial building sector. Research currently developing is the use of phase change materials (PCM) as thermal energy storage (TES) in the air conditioning system to reduce energy consumption. Salt hydrates have been great potential to be developed because they have been high latent heat and thermal conductivity. This study has used a salt hydrate from calcium chloride to be tested in air conditioning systems type chiller. Thermal characteristics were examined using temperature history (T-history) test and differential scanning calorimetry (DSC). The test results showed that the thermal characteristics of the salt hydrate has been a high latent heat and in accordance with the evaporator temperature. The use of salt hydrates in air conditioning system type chiller can reduce energy consumption by 51.5%.

  18. High SO{sub 2} removal duct injection: A low-cost FGD alternative

    SciTech Connect

    Nelson, S.G.

    1995-12-01

    Sorbent Technologies Corporation, of the United States, is currently developing and demonstrating a new waste free, retrofitable, high-SO{sub 2} removal duct-injection process. Up to 85 percent SO{sub 2} removal is achieved by simply injecting a new dry lime-based sorbent into the flue-gas duct, collecting the sorbent downstream in a particulate collector, and then recycling the sorbent. By avoiding large, expensive components, the process can have low capital costs, making it especially appropriate for smaller, older, less-utilized plants. The key to the new technology is the use of sorbent supports. Supported sorbents are produced by coating hydrated lime onto inexpensive mineral supports, such as exfoliated vermiculite or perlite. Consequently, there are no liquid, sludge, or solid wastes with the new technology. Once saturated with SO{sub 2}, the spent sorbent can be easily pelletized into a valuable soil-conditioning agricultural by-product, for the sustainable development that the future requires. This paper describes Sorbent Technologies` pilot demonstration of supported sorbent injection at the Ohio Edison Company`s R.E. Burger station. The Burger effort is also the first demonstration of the Electric Power Research Institute`s new {open_quotes}COHPAC{close_quotes} baghouse technology in a sorbent-injection desulfurization application.

  19. Simultaneous removal of NO and SO[sub 2] in packed scrubbers or spray towers

    SciTech Connect

    Harriott, P. ); Smith, K.; Benson, L.B. )

    1993-05-01

    Nitric oxide and sulfur dioxide can be removed from flue gas by scrubbing with a lime slurry containing ferrous EDTA. Tests in a 0.90m diameter column with several commercial packings gave 99 to 99.9 percent SO[sub 2] removal and 10 to 60 percent NO removal. The absorption of NO is controlled by the liquid-film resistance, and the number of transfer units varies with the square root of the ferrous EDTA concentration, the 0.4 to 0.6 power of the liquid rate, and the -1.0 power of the gas velocity, in agreement with predictions. The height of a transfer unit for NO absorption, corrected for end effects, was 10 to 15m, about 30 times the estimated values for SO[sub b] absorption, which is gas-film controlled. The spray tower gave lower removal rates for both gases, but the ratio of transfer units was about the same as for the packed columns. 8 refs., 5 figs., 1 tab.

  20. SO/sub 2/ concentration estimates for New York City, 1880-1980. Final report

    SciTech Connect

    Husar, R.B.; Patterson, D.E.

    1985-04-01

    The purpose of this investigation was to estimate the yearly ambient concentration of SO/sub 2/ and SO/sub 4/ wet deposition from 1880 to 1980 for the greater New York City area. This information was used to reconstruct ambient concentrations at two New York Veterans Administration cemeteries, Cypress Hills and Long Island, for studying marble deterioration. This study which involved a determination of marble loss rate as a function of SO2 concentrations is the subject of another report. The methodology for developing the retrospective model to estimate yearly ambient concentrations since the turn of the century for the greater New York City area is presented in this report. The retrospective estimation of sulfur concentration and deposition required estimation of both local and regional emission trends since the turn of the century, along with suitable choice of a local and a regional dispersion model to relate emissions to ambient concentrations and deposition. The retrospective estimates are compared to observed SO2 concentrations. It needs no elaboration that the estimation of local and regional emissions pertinent to a given receptor, the quantification of the local and regional contributions to SO2 and to the wet deposition, and reconciliation with existing observations is a formidable task. Lacking data for the historical trends, many of the assumptions are based on best available science, and they should be revised with the availability of new knowledge.

  1. Characterisation of Ba(OH){sub 2}–Na{sub 2}SO{sub 4}–blast furnace slag cement-like composites for the immobilisation of sulfate bearing nuclear wastes

    SciTech Connect

    Mobasher, Neda; Bernal, Susan A.; Hussain, Oday H.; Apperley, David C.; Kinoshita, Hajime; Provis, John L.

    2014-12-15

    Soluble sulfate ions in nuclear waste can have detrimental effects on cementitious wasteforms and disposal facilities based on Portland cement. As an alternative, Ba(OH){sub 2}–Na{sub 2}SO{sub 4}–blast furnace slag composites are studied for immobilisation of sulfate-bearing nuclear wastes. Calcium aluminosilicate hydrate (C–A–S–H) with some barium substitution is the main binder phase, with barium also present in the low solubility salts BaSO{sub 4} and BaCO{sub 3}, along with Ba-substituted calcium sulfoaluminate hydrates, and a hydrotalcite-type layered double hydroxide. This reaction product assemblage indicates that Ba(OH){sub 2} and Na{sub 2}SO{sub 4} act as alkaline activators and control the reaction of the slag in addition to forming insoluble BaSO{sub 4}, and this restricts sulfate availability for further reaction as long as sufficient Ba(OH){sub 2} is added. An increased content of Ba(OH){sub 2} promotes a higher degree of reaction, and the formation of a highly cross-linked C–A–S–H gel. These Ba(OH){sub 2}–Na{sub 2}SO{sub 4}–blast furnace slag composite binders could be effective in the immobilisation of sulfate-bearing nuclear wastes.

  2. Commercial demonstration of the NOXSO SO{sub 2}/NO{sub x} removal flue gas cleanup system. Quarterly technical progress report No. 10, June 1--August 31, 1993

    SciTech Connect

    1993-12-31

    The NOXSO process is a dry, post-combustion flue gas treatment technology which uses a regenerable sorbent to simultaneously adsorb sulfur dioxide (SO{sub 2}) and nitrogen oxides (NO{sub x}) from the flue gas of a coal-fired utility boiler. In the process, the SO{sub 2} is reduced to sulfur by-product (elemental sulfur, sulfuric acid, or liquid SO{sub 2}) and the NO{sub x} is reduced to nitrogen and oxygen. It is predicted that the process can economically remove 90% of the acid rain precursor gases from the flue gas stream in a retrofit or new facility. The objective of the NOXSO Demonstration Project is to design, construct, and operate a flue gas treatment system utilizing the NOXSO process at Ohio Edison`s Niles Plant Unit {number_sign}1. The effectiveness of the process will be demonstrated by achieving significant reductions in emissions of sulfur and nitrogen oxides. In addition, sufficient operating data will be obtained to confirm the process economics and provide a basis to guarantee performance on a commercial scale. The project is presently in the project definition and preliminary design phase. Data obtained during pilot plant testing which was completed on July 30, 1993 is being incorporated in the design of the commercial size plant. A suitable host site to demonstrate the NOXSO process on a commercial scale is presently being sought.

  3. Superposition-additive approach in the description of thermodynamic parameters of formation and clusterization of substituted alkanes at the air/water interface.

    PubMed

    Vysotsky, Yu B; Belyaeva, E A; Fomina, E S; Vasylyev, A O; Vollhardt, D; Fainerman, V B; Aksenenko, E V; Miller, R

    2012-12-01

    The superposition-additive approach developed previously was shown to be applicable for the calculations of the thermodynamic parameters of formation and atomization of conjugate systems, their dipole polarizability, molecular diamagnetic susceptibility, π-electronic ring currents, etc. In the present work, the applicability of this approach for the calculation of the thermodynamic parameters of formation and clusterization at the water/air interface of alkanes, fatty alcohols, thioalcohols, amines, nitriles, fatty acids (C(n)H(2n+1)X, X is the functional group) and cis-unsaturated carboxylic acids (C(n)H(2n-1)COOH) is studied. Using the proposed approach the thermodynamic quantities determined agree well with the available data, either calculated using the semiempirical (PM3) quantum chemical method, or obtained in experiments. In particular, for enthalpy and Gibbs' energy of the formation of substituted alkane monomers from the elementary substances, and their absolute entropy, the standard deviations of the values calculated according to the superposition-additive scheme with the mutual superimposition domain C(n-2)H(2n-4) (n is the number of carbon atoms in the alkyl chain) from the results of PM3 calculations for alkanes, alcohols, thioalcohols, amines, fatty acids, nitriles and cis-unsaturated carboxylic acids are respectively: 0.05, 0.004, 2.87, 0.02, 0.01, 0.77, and 0.01 kJ/mol for enthalpy; 2.32, 5.26, 4.49, 0.53, 1.22, 1.02, 5.30 J/(molK) for absolute entropy; 0.69, 1.56, 3.82, 0.15, 0.37, 0.69, 1.58 kJ/mol for Gibbs' energy, whereas the deviations from the experimental data are: 0.52, 5.75, 1.40, 1.00, 4.86 kJ/mol; 0.52, 0.63, 1.40, 6.11, 2.21 J/(molK); 2.52, 5.76, 1.58, 1.78, 4.86 kJ/mol, respectively (for nitriles and cis-unsaturated carboxylic acids experimental data are not available). The proposed approach provides also quite accurate estimates of enthalpy, entropy and Gibbs' energy of boiling and melting, critical temperatures and standard heat

  4. The role of SO{sub 4}{sup 2−} surface distribution in arsenic removal by iron oxy-hydroxides

    SciTech Connect

    Tresintsi, S.; Simeonidis, K.; Pliatsikas, N.; Vourlias, G.; Patsalas, P.; Mitrakas, M.

    2014-05-01

    This study investigates the contribution of chemisorbed SO{sub 4}{sup 2−} in improving arsenic removal properties of iron oxy-hydroxides through an ion-exchange mechanism. An analytical methodology was developed for the accurate quantification of sulfate ion (SO{sub 4}{sup 2−}) distribution onto the surface and structural compartments of iron oxy-hydroxides synthesized by FeSO{sub 4} precipitation. The procedure is based on the sequential determination of SO{sub 4}{sup 2−} presence in the diffuse and Stern layers, and the structure of these materials as defined by the sulfate-rich environments during the reaction and the variation in acidity (pH 3–12). Physically sorbed SO{sub 4}{sup 2−}, extracted in distilled water, and physically/chemically adsorbed ions on the oxy-hydroxide's surface leached by a 5 mM NaOH solution, were determined using ion chromatography. Total sulfate content was gravimetrically measured by precipitation as BaSO{sub 4}. To validate the suggested method, results were verified by X-ray photoelectron and Fourier-transformed infrared spectroscopy. Results showed that low precipitation pH-values favor the incorporation of sulfate ions into the structure and the inner double layer, while under alkaline conditions ions shift to the diffuse layer. - Graphical abstract: An analytical methodology for the accurate quantification of sulfate ions (SO{sub 4}{sup 2−}) distribution onto the diffuse layer, the Stern layer and the structure of iron oxy-hydroxides used as arsenic removal agents. - Highlights: • Quantification of sulfate ions presence in FeOOH surface compartments. • Preparation pH defines the distribution of sulfates. • XPS and FTIR verify the presence of SO{sub 4}{sup 2−} in the structure, the Stern layer the diffuse layer of FeOOH. • Chemically adsorbed sulfates control the arsenic removal efficiency of iron oxyhydroxides.

  5. SO>2-Resistant Immobilized Amine Sorbents for CO2 Capture

    SciTech Connect

    Tumuluri, Uma

    2014-01-01

    The solid amine sorbent for CO2 capture process has advantages of simplicity and low operating cost compared to the MEA (monoethanolamine) process. Solid amine sorbents reported so far suffered from either low CO2 capture capacity or low stability in the flue gas environment. This project is aimed at developing a SO>2-resistant solid amine sorbent for capturing CO2 from coal–fired power plants with SCR/FGD which emits SO>2ranging from 15 to 30 ppm and NO ranging from 5 to 10 ppm. The amine sorbent we developed in a previous project degraded rapidly with 65% decrease in the initial capture capacity in presence of 1% SO>2. This amine sorbent was further modified by coating with polyethyleneglycol (PEG) to increase the SO>2-resistance. Polyethylene glycol (PEG) was found to decrease the SO>2-amine interaction, resulting in the decrease in the maximum SO desorption temperature (Tmax ) of amine sorbent. The PEG-coated amine sorbent exhibited higher stability with only 40% decrease in the initial capture capacity compared to un-coated amine sorbents. The cost of the solid amine sorbent developed in this project is estimated to be less than $7.00/lb; the sorbent exhibited CO2 capture capacity more than 2.3 mmol/g. The results of this study provided the scientific basis for further development of SO>2-resistant sorbents.

  6. Emissions of industrial furnaces burning diesel fuel oils of various sulfur contents with NaCl - contained atmospheric air

    SciTech Connect

    Lin, C.Y.; Hsieh, M.J.

    1996-04-01

    A small furnace associated with an industrial automatic burner was employed in this study to investigate the influences of sulfur content of fuel oils burned with NaCl contained atmospheric air on the emission characteristics of marine or industrial power-plants. The sulfur contents of 0.3 wt% and 1.0 wt% were considered. Diesel fuel oil A which approximates ASTM No. 2 fuel oil was atomized by the inlet air added with NaCl of 1.5 ppm concentration and thereafter burned within the furnace. It was found that under this burning condition the CO, SO{sub 2}, and O{sub 2} emissions increased with the addition of sulfur in the fuel oil. However, the gas temperature and NO{sub x} concentration were affected by the increase of sulfur content to only a minor extent. 14 refs., 10 figs.

  7. Surface Structure Dependence of SO>2 Interaction with Ceria Nanocrystals with Well-defined Surface Facets

    SciTech Connect

    Tumuluri, Uma; Li, Meijun; Cook, Brandon G.; Sumpter, Bobby G.; Dai, Sheng; Wu, Zili

    2015-12-02

    The effects of the surface structure of ceria (CeO2) on the nature, strength, and amount of species resulting from SO>2 adsorption were studied using in situ IR and Raman spectroscopies coupled with mass spectrometry, along with first-principles calculations based on density functional theory (DFT). CeO2 nanocrystals with different morphologies, namely, rods (representing a defective structure), cubes (100 facet), and octahedra (111 facet), were used to represent different CeO2 surface structures. IR and Raman spectroscopic studies showed that the structure and binding strength of adsorbed species from SO>2 depend on the shape of the CeO2 nanocrystals. SO>2 adsorbs mainly as surface sulfites and sulfates at room temperature on CeO2 rods, cubes, and octahedra that were either oxidatively or reductively pretreated. The formation of sulfites is more evident on CeO2 octahedra, whereas surface sulfates are more prominent on CeO2 rods and cubes. This is explained by the increasing reducibility of the surface oxygen in the order octahedra < cubes < rods. Bulk sulfites are also formed during SO>2 adsorption on reduced CeO2 rods. The formation of surface sulfites and sulfates on CeO2 cubes is in good agreement with our DFT results of SO>2 interactions with the CeO2(100) surface. CeO2 rods desorb SO2 at higher temperatures than cubes and octahedra nanocrystals, but bulk sulfates are formed on CeO2 rods and cubes after high-temperature desorption whereas only some surface sulfates/sulfites are left on octahedra. This difference is rationalized by the fact that CeO2 rods have the highest surface basicity and largest amount of defects among the three nanocrystals, so they bind and react with SO>2 strongly and are the most degraded after SO>2 adsorption cycles. The

  8. Physicochemical investigation of UO/sub 2/SO/sub 3//centered dot/3H/sub 2/O

    SciTech Connect

    Blatov, V.A.; Serezhkina, L.B.; Serezhkin, V.N.

    1988-09-01

    The thermal stability of UO/sub 2/SO/sub 3//centered dot/3H/sub 2/O was investigated, and its crystallographic characteristics were determined. The IR spectra of UO/sub 2/SO/sub 3//centered dot/nH/sub 2/O ( n /equals/ 3 or 4, 5) are discussed. An assumption regarding the structure of uranyl sulfite hydrates and their affiliation with the AT/sup 3/M/sub 2//sup 1/ crystal-chemical group is expressed.

  9. Atmospheric transport and deposition of acidic air pollutants

    SciTech Connect

    Murphy, C.E. Jr.

    1981-01-01

    Although general principles which govern atmospheric chemistry of sulfur are understood, a purely theoretical estimation of the magnitude of the processes is not likely to be useful. Furthermore, the data base necessary to make empirical estimates does not yet exist. The sulfur budget of the atmosphere appears to be dominated by man-associated sulfur. The important processes in deposition of man-associated sulfur are wet deposition of sulfate and dry deposition of SO/sub 2/. The relative importance of sulfate and SO/sub 2/ to sulfur deposition (input to watersheds) depends on the air concentrations, and either compound may be the greater contributor depending on conditions. (PSB)

  10. Determination of antimony, arsenic, bismuth, selenium, tellurium and tin by low pressure atomic absorption spectrometry with a quartz tube furnace atomizer and hydride generation with air addition.

    PubMed

    Zhang, B; Wang, Y; Wang, X; Chen, X; Feng, J

    1995-08-01

    A new method has been developed for the determination of antimony, arsenic, bismuth, selenium, tellurium and tin by hydride generation-atomic absorption spectrometry in an electrically heated quartz tube furnace under sub-atmospheric pressure. The hydride generator, operating at a pressure lower than atmospheric, is used to generate and collect the hydrides of these elements. A certain volume (at atmospheric pressure) of air is then added to the generator after the formation of the volatile hydride. The gaseous mixture of the hydride and air is drawn into an evacuated, heated quartz tube by a vacuum pump. The proposed method gives improved sensitivities and detection limits.

  11. A combined SO{sub 2} and NO{sub x} scrubbing process

    SciTech Connect

    Breault, R.W.; Bittenson, S.; Lani, B.

    1998-07-01

    A new wet scrubber process has been developed and undergone preliminary testing to verify the viability of a zero discharge system for SO{sub 2} and NO{sub x} removal. The process combines the Dravo ThioClear{reg{underscore}sign} process with Tecogen's TecoLytic{trademark} process. The integration of these two technologies results a system that removes both SO{sub 2} and NO{sub x} while producing only salable byproducts. These by-products are wall board grade gypsum, magnesium hydroxide and up to 60 weight percent fertilizer grade calcium nitrate solution. Hence, a zero waste, zero discharge wet scrubber system is being demonstrated. The core of the integrated technology consists of two parts. The first part is the ThioClear process. In this process, a highly alkaline magnesium sulfite solution is used to capture the SO{sub 2} in a high velocity (greater than 15 ft/s with a nominal design of 25 ft/s) horizontal scrubber. Once captured, the sulfites are oxidized to sulfates in an oxidizing vessel. The effluent from the oxidizer is reacted with a magnesium-enhanced lime slurry to raise the pH to about 10.5. At this higher pH, 6 to 10{micro} magnesium hydroxide precipitates and 80{micro} or larger gypsum precipitates are formed. Subsequent product purification produces salable gypsum and magnesium hydroxide. The flue gas continues through the high velocity horizontal scrubber passing through the TecoLytic{trademark} section. In this section, high voltage is applied to produce highly reactive excited species. These species interact with the water vapor present to produce hydroxyl radicals while simultaneously oxidizing the NO to NO{sub 2}. The hydroxyl radicals rapidly oxidize the NO{sub 2} to nitric acid which is scrubbed in the second stage of the horizontal scrubber with a calcium nitrate--lime solution. Bench scale tests have shown high potential. A pilot plant facility has been installed at Cincinnati Gas and Electric Company's Miami Fort facility. Pilot tests at

  12. SNRB{trademark} air toxics monitoring. Final report

    SciTech Connect

    Not Available

    1994-01-01

    Babcock & Wilcox (B&W) is currently conducting a project under the DOE`s Clean Coal Technology (CCT II) Program to demonstrate its SO{sub x}NO{sub x}-Rox Box{trademark} (SNRB{trademark}) process in a 5 MWe Field Demonstration Unit at Ohio Edison`s R. E. Burger Plant near Shadyside, Ohio. The objective of the SNRB{trademark} Air Toxics Monitoring Project was to provide data on SNRB{trademark} air toxics emissions control performance to B&W and to add to the DOE/EPRI/EPA data base by quantifying the flow rates of selected hazardous substances (or air toxics) in all of the major input and output streams of the SNRB{trademark} process as well as the power plant. Work under the project included the collection and analysis of representative samples of all major input and output streams of the SNRB{trademark} demonstration unit and the power plant, and the subsequent laboratory analysis of these samples to determine the partitioning of the hazardous substances between the various process streams. Material balances for selected air toxics were subsequently calculated around the SNRB{trademark} and host boiler systems, including the removal efficiencies across each of the major air pollution control devices. This report presents results of the SNRB{trademark} Air Toxics Monitoring Project. In addition to the Introduction, a brief description of the test site, including the Boiler No. 8 and the SNRB{trademark} process, is included in Section H. The concentrations of air toxic emissions are presented in Section II according to compound class. Material balances are included in Section IV for three major systems: boiler, electrostatic precipitator, and SNRB{trademark}. Emission factors and removal efficiencies are also presented according to compound class in Sections V and VI, respectively. A data evaluation is provided in Section VII.

  13. Modeling the effects of changes in new source review on national SO{sub 2} and NOx emissions from electricity-generating units

    SciTech Connect

    David A. Evans; Benjamin F. Hobbs; Craig Oren; Karen L. Palmer

    2008-01-15

    The Clean Air Act establishes New Source Review (NSR) programs that apply to construction or modification of major stationary sources. In 2002 and 2003, EPA revised its rules to narrow NSR's coverage of renovations. Congress mandated a National Research Council study of the revisions' impacts. In that study, we used an electricity-sector model to explore possible effects of the equipment replacement provision (ERP), the principal NSR change directed at power plants. We find that, assuming implementation of the Clean Air Interstate Rule (CAIR), tight enforcement of the prerevision NSR rules would likely lead to no or limited decreases in national emissions compared to policies such as ERP. However, emissions might shift forward in time because the previous NSR rules would depress allowance prices, discouraging banking and encouraging allowance use. Only under the most aggressive prerevision NSR enforcement scenario, in which essentially all coal capacity is compelled to retrofit controls by 2020, do NOx emissions fall below ERP levels. Even then, total 2007-2020 SO{sub 2} emissions are unaffected. Further decreases in national emissions could be accomplished more cheaply by tighter emissions caps than through NSR because caps provide incentives for efficient operating strategies, such as fuel switching, as well as retrofits. 23 refs., 2 figs., 1 tab.

  14. Producing vapor grown carbon fibers with high sulfur coal without SO{sub 2} emissions

    SciTech Connect

    Alig, R.; Lake, M.; Guth, J.; Burton, D.

    1995-12-31

    This paper describes the development of a unique process that produces a highly graphitic, vapor grown carbon fiber (VGCF) from the gas phase in pound quantities. Past vapor grown carbon fiber progress has stagnated because the iron catalyst did not grow filaments profusely enough to make a practical continuous reactor. It has been found that adding H{sub 2}S at an equimolar level with the iron catalyst, the filament formation vastly increases. Coal is desirable as a sulfur source, for it eliminates the need for handling toxic H{sub 2}S, and it is a very low cost hydrocarbon supply for the process. We show that Ohio, high-sulfur coal containing 2.5 to 4.6% sulfur accomplishes both tasks. There is also evidence that sulfur from the coal remains with the carbon fiber catalyst during the reaction and does not exhaust as SO{sub 2} into the atmosphere.

  15. Effects of rheological change by addition of carboxymethylcellulose in culture media of an air-lift fermentor on poly-D-3-hydroxybutyric acid productivity in autotrophic culture of hydrogen-oxidizing bacterium, Alcaligenes eutrophus.

    PubMed

    Taga, N; Tanaka, K; Ishizaki, A

    1997-03-05

    The effects of rheological change by addition of sodium carboxymethylcellulose (CMC) to culture medium in an air-lift-type fermentor on autotrophic production of poly-(D-3-hydroxybutyric acid) [P(3HB)] by two-stage culture of Alcaligenes eutrophus is investigated. Addition of 0.05% CMC increased P(3HB) production rate during the P(3HB) accumulation phase to twice that of the control culture. It was thought that addition of a small amount of CMC was beneficial for production of P(3HB) employing the air-lift fermentor under safe autotrophic culture conditions in wich oxygen concentration was maintained below 6.9% (v/v). the volumetric mass transfer coefficient (K(L)a) observed in the presence of CMC is shown to correlated with the P(3HB) production rate obtained. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 53: 529-533, 1997.

  16. SO/sub 2/(g)-to-sulfate conversion rate in an oil-fired-power-plant plume in a fog bank

    SciTech Connect

    Eatough, D.J.; Arthur, R.J.; Eatough, N.L.; Hill, M.W.; Mangelson, N.F.; Richter, B.E.; Hansen, L.D.; Cooper, J.A.

    1983-01-01

    High acidity in rainfall, cloud droplets and fog droplets in areas influenced by anthropogenic sources of SO/sub 2/(g) and NO/sub x/(g) has been attributed to the formation of both H/sub 2/SO/sub 4/ and HNO/sub 3/. It has been suggested, based on the analysis of field data, that rapid conversion of SO/sub 2/(g) to sulfate must occur in cloud or fog droplets. Direct measurements of the rate of SO/sub 2/(g) to sulfate conversion in an oil-fired power plant plume as it passes through a fog bank are reported here. A conversion rate of 30+-4% SO/sub 2/(g) h/sup -1/ was found in the fog bank.

  17. Method of using a nuclear magnetic resonance spectroscopy standard. [SO/sub 2/ in gases by fluorescence

    DOEpatents

    Spicer, L.D.; Bennett, D.W.; Davis, J.F.

    1983-05-09

    (CH/sub 3/)/sub 3/SiNSO is produced by the reaction of ((CH/sub 3/)/sub 3/SI)/sub 2/NH with SO/sub 2/. Also produced in the reaction are ((CH/sub 3/)/sub 3/Si)/sub 2/O and a new solid compound (NH/sub 4/)((CH/sub 3/)/sub 3/SiOSO/sub 2/). Both (CH/sub 3/)/sub 3/SiNSO and (NH/sub 4/)((CH/sub 3/)/sub 3/SiOSO/sub 2/) have fluorescent properties. The reaction of the subject invention is used in a method of measuring the concentration of SO/sub 2/ pollutants in gases. By the method, a sample of gas is bubbled through a solution of ((CH/sub 3/)/sub 3/Si)/sub 2/NH, whereby any SO/sub 2/ present in the gas will react to produce the two fluorescent products. The measured fluorescence of these products can then be used to calculate the concentration of SO/sub 2/ in the original gas sample. The solid product (NH/sub 4/)((CH/sub 3/)/sub 3/SiOSO/sub 2/) may be used as a standard in solid state NMR spectroscopy, wherein the resonance peaks of either /sup 1/H, /sup 13/C, /sup 15/N, or /sup 29/Si may be used as a reference.

  18. Simultaneous SO[sub 2]/NO/particulate removal from coal combustion gas by solid-state electrochemical technology

    SciTech Connect

    Cornell, L.P.; Cook, W.J.; Keyvani, M.; Neyman, M. ); Helfritch, D.J. . Environmental Services and Technologies Div.)

    1991-01-21

    A solid-state electrochemical process now in an early stage of development converts NO[sub x]and SO[sub x] to nitrogen, oxygen, and sulfur. Process objectives are to remove 90+% of SO[sub x] and NO[sub x] and 99% of particulates from Ohio coal combustion flue gases. The electrochemical reactor cell uses ionically conductive ceramics as electrolyte, and electronically conductive materials (including some ceramics) as electrodes; there are no moving parts, no consumable reagents, no by-product sludges, and no process fluids except the flue gas. Downstream of the electro-chemical cell, particulates are removed with a filter or electrostatic precipitator and elemental sulfur is condensed. This work developed and tested electrocatalysts for their ability to selectively reduce SO[sub 2] and NO[sub x] in the presence of oxygen gas in concentrations typical of coal combustion flue gases. Several solid electrolytes and various electrode materials were also tested for use in the electrochemical cell. Gold was chosen as the electrode in the tests because it is porous, resistant to chemical attack, and conductive. Electrocatalyst coatings containing a single transition metal were applied to one inch diameter yttria stabilized ceria disks and tested for NO and SO[sub 2] reduction.

  19. Effect of Ag nanoparticles deposition on photocatalytic activity of Ag{sub 2}SO{sub 3}

    SciTech Connect

    Zhang, Xuan Wang, Qi; Hu, Jin-Wen; Zou, Lan-Hua; You, Jia-Wen

    2016-03-15

    Highlights: • Ag{sub 2}SO{sub 3} was developed as novel photocatalyst. • The effect of Ag nanoparticles deposition on photocatalytic activity was investigated. • The activation and deactivation mechanism was proposed. - Abstract: A novel photocatalyst Ag{sub 2}SO{sub 3} was prepared and the effect of Ag nanoparticles, photo-deposited on the surface of Ag{sub 2}SO{sub 3}, on its photocatalytic activity was investigated. The as-prepared photocatalyst was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV–vis diffuse reflection spectroscopy (DRS). The photocatalytic activity was evaluated by photo-degradation of rhodamine B dye under UV light irradiation. It was found that the photocatalytic activity of Ag{sub 2}SO{sub 3} was initially enhanced with deposition of Ag nanoparticles, but subsequently declined with Ag nanoparticles overloaded. The possible mechanism was proposed based on experimental results. These findings may contribute to developing novel photocatalysts and understanding of fundamentals of Ag-based photocatalytic materials.

  20. Influence of air pollution on extrinsic childhood asthma

    SciTech Connect

    Berciano, F.A.; Dominguez, J.; Alvarez, F.V.

    1989-02-01

    A crossed comparative study was done with 248 extrinsic asthmatic children living either in polluted or non-polluted areas (mean emission per year of sedimentary material greater than or less than 300 mg/m2/day, respectively) to establish the influence of air pollution on childhood extrinsic asthma. The mean number of wheezing crises per year was significantly higher for the children living in polluted areas (10.4 versus 7.69). In addition, incidence of severe asthma (types II, III, and IV) in children living in polluted areas was markedly increased whereas the slight form of asthma (type I) was more frequent in children living in non-polluted areas. No correlation, however, between the wheezing episodes and levels of atmospheric contaminants (fumes and SO/sub 2/) was detected when a group of 84 extrinsic asthmatic children living in polluted areas was studied longitudinally for a year. The data indicate that air pollution, as an isolated agent, plays a transient role in the appearance of wheezing episodes in subjects with extrinsic asthma. Results also suggest that the air pollution may potentiate wheezing episodes via alternative mechanisms.

  1. Formation of Langmuir Monolayers of Titanium Dioxide Nanoparticles at Air/Aqueous Interfaces by the Addition of Ions to the Subphase: Effect of Ion Concentration and Type.

    PubMed

    Iwafuji, Yuya; McNamee, Cathy E

    2015-09-17

    A Langmuir monolayer of bare, hydrophilic TiO2 nanoparticles (diameter = 75 nm) was formed at an air/pH 5.8 aqueous interface by adding salt to the subphase. The effect of the concentration and type of salt in the subphase on the surface pressure-area per particle isotherms was determined. Increasing the concentration of NaCl from 0 to 3.8 M increased the maximum surface pressure (Πmax) and shifted the isotherms to a larger area per particle. The ion type also affected the area at which the close packing commenced and the value of Πmax. The presence of salt in the subphase also stabilized SiO2 nanoparticles, suggesting that the ions in the subphase interacted with the dioxide groups on the particles. The combination of structure making or borderline ions with structure breaking ions (LiCl, MgCl2, NaCl, and CaCl2) appeared to stabilize the particulate monolayers more than the combination of structure breaking ions (KBr and KCl). These results suggested that the particles were stabilized by a hydrogen bond network between the particles or the formation of a salt bridge between the particles. Attractions between particles at the air/aqueous interface caused the particles to aggregate, resulting in the particles becoming more stable at the air/aqueous interface.

  2. Analysis of the Clean Air Act Amendments of 1990: A forecast of the electric utility industry response to Title IV, Acid Deposition Control

    SciTech Connect

    Molburg, J.C.; Fox, J.A.; Pandola, G.; Cilek, C.M.

    1991-10-01

    The Clean Air Act Amendments of 1990 incorporate, for the first time, provisions aimed specifically at the control of acid rain. These provisions restrict emissions of sulfur dioxide (SO[sub 2]) and oxides of nitrogen (NO[sub x]) from electric power generating stations. The restrictions on SO[sub 2] take the form of an overall cap on the aggregate emissions from major generating plants, allowing substantial flexibility in the industry's response to those restrictions. This report discusses one response scenario through the year 2030 that was examined through a simulation of the utility industry based on assumptions consistent with characterizations used in the National Energy Strategy reference case. It also makes projections of emissions that would result from the use of existing and new capacity and of the associated additional costs of meeting demand subject to the emission limitations imposed by the Clean Air Act. Fuel-use effects, including coal-market shifts, consistent with the response scenario are also described. These results, while dependent on specific assumptions for this scenario, provide insight into the general character of the likely utility industry response to Title IV.

  3. Analysis of the Clean Air Act Amendments of 1990: A forecast of the electric utility industry response to Title IV, Acid Deposition Control

    SciTech Connect

    Molburg, J.C.; Fox, J.A.; Pandola, G.; Cilek, C.M.

    1991-10-01

    The Clean Air Act Amendments of 1990 incorporate, for the first time, provisions aimed specifically at the control of acid rain. These provisions restrict emissions of sulfur dioxide (SO{sub 2}) and oxides of nitrogen (NO{sub x}) from electric power generating stations. The restrictions on SO{sub 2} take the form of an overall cap on the aggregate emissions from major generating plants, allowing substantial flexibility in the industry`s response to those restrictions. This report discusses one response scenario through the year 2030 that was examined through a simulation of the utility industry based on assumptions consistent with characterizations used in the National Energy Strategy reference case. It also makes projections of emissions that would result from the use of existing and new capacity and of the associated additional costs of meeting demand subject to the emission limitations imposed by the Clean Air Act. Fuel-use effects, including coal-market shifts, consistent with the response scenario are also described. These results, while dependent on specific assumptions for this scenario, provide insight into the general character of the likely utility industry response to Title IV.

  4. The addition of ortho-hexagon nano spinel Co3O4 to improve the performance of activated carbon air cathode microbial fuel cell.

    PubMed

    Ge, Baochao; Li, Kexun; Fu, Zhou; Pu, Liangtao; Zhang, Xi

    2015-11-01

    Commercial Co3O4 and ortho-hexagon spinel nano-Co3O4 (OHSNC) were doped in the AC at a different percentage (5%, 10% and 15%) to enhance the performance of microbial fuel cell (MFC). The maximum power density of MFC with 10% OHSNC doped cathode was 1500±14 mW m(-2), which was 97.36% and 41.24% higher than that with the bare AC air cathode and commercial Co3O4 respectively. The electrocatalytic behavior for their better performance was discussed in detail with the help of various structural and electrochemical techniques. The OHSNC was characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM). The results showed that the improved performance owed to the enhancement of both kinetics activity and the number of electron transfer in the ORR, and the internal resistance was largely reduced. Therefore, OHSNC was proved to be an excellent cathodic catalyst in AC air cathode MFC.

  5. Low-energy elastic and inelastic scattering of electrons from SO{sub 2} using the R-matrix method

    SciTech Connect

    Gupta, Monika; Baluja, K. L.

    2006-04-15

    R-matrix method is used to calculate elastic differential, integral, and momentum transfer cross sections for electron-SO{sub 2} collision. The electron-impact excitation cross sections for first seven low-lying electronic excited states of SO{sub 2} molecule from the ground state of SO{sub 2} molecule have been calculated for the first time. Sixteen low-lying electronic states of SO{sub 2} molecule are included in the close coupling expansion of the wave function of the entire scattering system, which have vertical excitation energies up to 10.51 eV. Configuration-interaction (CI) wave functions are used to calculate these excitation energies. In our CI model, we keep the core 14 electrons frozen in doubly occupied molecular orbitals 1a{sub 1}, 2a{sub 1}, 3a{sub 1}, 4a{sub 1}, 1b{sub 1}, 1b{sub 2}, 2b{sub 2} and the remaining 18 electrons span the relevant active space: 5a{sub 1}, 6a{sub 1}, 7a{sub 1}, 8a{sub 1}, 9a{sub 1}, 2b{sub 1}, 3b{sub 1}, 3b{sub 2}, 4b{sub 2}, 5b{sub 2}, 6b{sub 2}, and 1a{sub 2}. Our calculated dipole moment of the ground state of SO{sub 2} at its equilibrium geometry is 0.79 a.u., which is in reasonable agreement with the corresponding experimental value 0.64 a.u. Our calculations detect one bound SO{sub 2}{sup -} state ({sup 2}B{sub 1}) at the equilibrium geometry of SO{sub 2} molecule. Both shape as well as core-excited shape resonances have been identified in the present work and are correlated with the experimental results on dissociative electron attachment study. A detailed analysis of resonances is provided. Cross sections are reported for the electron impact energy range 0-15 eV. All cross section calculations are performed in the fixed-nuclei approximation at the experimental equilibrium geometry of the ground state of SO{sub 2} molecule. We have also investigated dependence of resonances on the geometry of SO{sub 2} molecule to probe the possible pathways for dissociation of resulting negative ion upon electron attachment. We

  6. Stomatal response and leaf injury of Pisum sativum L. with SO/sub 2/ and O/sub 3/ exposures. I. Influence of pollutant level and leaf maturity

    SciTech Connect

    Olszyk, D.M.; Tibbitts, T.W.

    1981-03-01

    Plants of Pisum sativum L. Alsweet were grown under a controlled environment and exposed to SO/sub 2/ and O/sub 3/ to determine whether changes in stomatal aperture during exposure were related to subsequent leaf injury. Stomata consistently closed with injurious levels of SO/sub 2/ and O/sub 3/. Measurements with diffusion porometers demonstrated approx. = 75 and 25% lower conductance with SO/sub 2/ and O/sub 3/ exposures, respectively, compared to the conductance of control plants. Stomata also showed a closing response with noninjurious levels of SO/sub 2/ but an opening response with noninjurious levels of O/sub 3/. Stomata closed to the same degree with combinations of SO/sub 2/ plus O/sub 3/ as with SO/sub 2/ alone. Stomata of expanding leaves closed more during pollutant exposures than stomata of expanded leaves. The abaxial and adaxial stomata both exhibited closure with SO/sub 2/ and combinations of SO/sub 2/ plus O/sub 3/, but abaxial stomata tended to close and adaxial stomata tended to open with exposure to O/sub 3/ alone. The changes in stomatal aperture were not closely correlated with the amount of leaf injury produced by different pollutant levels. Stomata closed, not only with exposure to pollutant levels that caused severe necrosis, but also with levels that caused only a trace of injury. There was no evidence of a reduced amount of closure or even stomatal opening with combinations of SO/sub 2/ and O/sub 3/ compared to plants exposed to the pollutants alone to explain the large amount of injury to plants exposed to pollutant combinations.

  7. Human health benefits of ambient sulfate aerosol reductions under Title IV of the 1990 Clean Air Act amendments

    SciTech Connect

    Chestnut, L.G.; Watkins, A.M.

    1997-12-31

    The Acid Rain Provisions (Title IV) of the Clean Air Act Amendments of 1990 call for about a 10 million ton reduction in annual SO{sub 2} emissions in the United States by the year 2010. Although the provisions apply nationwide, most of the reduction will take place in the eastern half of the United States, where use of high sulfur coal for electricity generation is most common. One potentially large benefit of Title IV is the expected reduction in adverse human health effects associated with exposure to ambient sulfate aerosols, a secondary pollutant formed in the atmosphere when SO{sub 2} is present. Sulfate aerosols are a significant constituent of fine particulate (PM{sub 2.5}). This paper combines available epidemiologic evidence of health effects associated with sulfate aerosols and economic estimates of willingness to pay for reductions in risks or incidence of health effects with available estimates of the difference between expected ambient sulfate concentrations in the eastern United States and southeastern Canada with and without Title IV to estimate the expected health benefits of Title IV. The results suggest a mean annual benefit in the eastern United States of $10.6 billion (in 1994 dollars) in 1997 and $40.0 billion in 2010, with an additional $1 billion benefit each year in Ontario and Quebec provinces.

  8. Mercury removal from coal by leaching with SO{sub 2}

    SciTech Connect

    Eung Ha Cho; Poornima Chateker; Ravinder Garlapalli; Ray Y.K. Yang

    2009-01-15

    This paper is about the pretreatment of coal to remove mercury content prior to coal combustion. The minute amount of mercury in Pittsburgh No. 8 coal (0.177 ppm) was removed by flowing a gas stream containing 10% oxygen and 1000 ppm SO{sub 2} into a coal-water slurry at 30 mL/s. A total of 50 g of 35-65 mesh coal was leached each time in 500 mL of solution. The temperature was varied from 50 to 80{sup o}C and the initial solution pH varied at 5.7, 1.8, and 1.5. It was found that the mercury removal increased from 44.2% at 50{sup o}C to 88.6% at 75{sup o}C at the natural pH (5.7) and after 3 h of reaction time. The pyrite conversions were much lower than those of mercury. Both the mercury and pyrite removals increased as the pH decreased at 71{sup o}C. Mercury removal was high enough to consider the application of this technology to a commercial process. 10 refs., 11 figs.

  9. Preliminary field measurements on the sources of SO{sub 4}{sup =} in maritime cloud water

    SciTech Connect

    Samberg, T.M.; Hegg, D.A.; Kok, G.L.

    1995-12-01

    Sulfate production in marine clouds has climatic implications given that this process may alter the efficiency by which existing sulfate aerosol particles scatter incoming solar radiation and/or alter the albedo of clouds by changing the number population of aerosols that can serve as CCN. Previous attempts at quantitation of sulfate production are limited, with very few measurements of sulfate production made in the marine regime. Husain (1989) developed a novel approach for determining sulfate production in urban clouds using a selenium tracer method. We have attempted to apply this method to the marine case. Preliminary results from the CACHE-2 and CACHE-3 (Cloud and Aerosol Chemistry Experiment) field projects, conducted at the Cheeka Peak Research Station on the coast of Washington during April/May 1994 and August/September 1994, respectively, will be presented. Chemical and physical measurements made include cloud water and interstitial concentrations SO{sub 4}{sup =} and Se, gas phase O{sub 3}, gas phase H{sub 2}O{sub 2}, cloud water H{sub 2}O{sub 2}, cloud liquid water content, and droplet number concentration.

  10. Anthropogenic SO{sub 2}/NO{sub x} committee--current status

    SciTech Connect

    Benkovitz, C.M.

    1993-04-01

    Current activities of the Anthropogenic SO{sub 2}/NO{sub x} Committee center around the compilation of Version 1 of the GEIA inventories. These inventories will be based on the GEIA-specified 1{degrees} by 1{degrees} grid (lower left corner at 180{degrees}W/90{degrees}S, west to east and south to north), reflect 1985 emissions and consist of two data sets: Version 1A inventories with annual emissions at one level and Version 1B inventories with seasonal emissions, two vertical levels (defined at 100 m) and sectoral split information. The basic information used for both versions of the GEIA inventories will be identical; i.e., emissions totals across both inventories will be the same. Work is being carried out in two complementary working groups; Carmen Benkovitz, Brookhaven National Laboratory, Upton, NY, USA heads the work on the annual inventory, Eva Voldner, Atmospheric Environment Services, Canada and Trevor Scholtz, ORTECH International, Canada, head the work on the seasonal inventory.

  11. Climate regulation by marine phytoplankton. : A test by anthropogenic SO/sub 2/ emissions

    SciTech Connect

    Schwartz, S.E.

    1989-05-01

    The potential sensitivity of global mean albedo and temperature to N prompted a novel suggestion consistent with the Gaia hypothesis for regulation of global climate by marine phytoplankton. Certain species of coccolithophores excrete dimethylsulfide (DMS), and this DMS is arguably the principal source of reduced sulfur gases in the global atmosphere and, in the absence of anthropogenic SO/sub 2/, the principal source of atmospheric gaseous sulfur species. Such gaseous sulfur species are oxidized in the atmosphere to form sulfuric acid, which rapidly forms an aerosol. Since sulfate-containing AP are highly efficient CCN, it is argued that an increase in DMS production by marine phytoplankton would yield increased concentrations of CCN, resulting in increased cloud albedo, decreased surface insolation, and decreased planetary temperature. It is further hypothesized that such decreased insolation or temperature might result in decreased production of DMS by marine phytoplankton, i.e., that the process might constitute a negative feedback loop for regulation of planetary climate by marine microorganisms. 18 refs., 3 figs., 1 tab.

  12. High temperature membranes for H[sub 2]S and SO[sub 2] separations

    SciTech Connect

    Winnick, J.

    1992-01-01

    Successful removal of SO[sub x] from flue gas depends on the development of a membrane able to achieve a current density of 50 mA/cm[sup 2] at a total voltage of approximately 1V. Flooding of electrode hasbeen identified as a problem, leading to increasing polarization over time. The resulting reduction of surface area also tends to limit the mass transfer flux, reducing the efficiency of the cell. To reduce flooding, new materials and techniques of manufacture will be investigated, in the attempt to produce a ceramic membrane of approximately 50% theoretical density. This membrane must have proper pore size distribution to ensure sufficient capillary force to prevent impregnated electrolyte from flooding electrodes, and subsequently drying the ceramic membrane. Various methods of matrix production were studied this quarter: tape casting, pressing and sintering, and slip casting. Each will be discussed in turn. Electrolyte introduction to the cell is a continuing problem. The development of a method is still being investigated. Ideally, the electrolyte would be introduced as powder with binder in a green body. This binder would burn away at temperatures of approximately 300[degrees]C, leaving pure electrolyte to melt and complete the ionic path necessary for the electrochemical cell. The electrolyte used this quarter was, exclusively, a 90 wt % K[sub 2]S[sub 2]O[sub 7]/10 wt % V[sub 2]O[sub 5] mixture.

  13. Circulating fluidized-bed boilers: Enhancing reagent utilization while maintaining proper SO{sub 2} removal

    SciTech Connect

    Dubose, R.E.; Ray, D.M.; Wofford, J.; Buecker, B.

    1997-12-31

    Unit performance, and related operation and maintenance costs, for circulating fluidized bed (CFB) combustors are very dependent on the sorbent selected for SO{sub 2} removal. Limestone is the typical reagent of choice, but variations in quality can have a dramatic impact on the reaction efficiency. This paper discusses the results of full-scale tests and subsequent use of a high-quality sorbent in the two CFBs serving the University of North Carolina at Chapel Hill. The tests were necessary because of the desire to optimize performance based on the economics of limestone utilization and ash disposal. It was considered, also, that the reagent in use prior to the tests was not very reactive and caused ash handling problems. Project organizers used the full-scale tests to examine the effects of sorbent quality and grind size on the efficiency of the process. The tests indicated that reagent consumption would be reduced by 50% or more with the new sorbent. Plant personnel verified this conclusion when they began feeding the new reagent on a permanent basis. Reagent usage and ash production significantly decreased and have remained low in the three years since the change was made. The results outlined in this paper clearly indicate the large impact that reagent quality has on CFB operation. For present and prospective CFB managers, these results can justify the search for, and use of, limestone sorbents that might otherwise be considered too expensive or too distant from the plant. 39 figs.

  14. Final Environmental Assessment: For Construction of an Addition to the Joint Strike Fighter Reprogramming Facility, Building 614, on Eglin Air Force Base, Florida

    DTIC Science & Technology

    2007-01-01

    located approximately 0.8 miles south of Lewis Middle School . Additionally, the construction site would be fenced, preventing unauthorized access...boiler insulation, acoustical ceilings, sprayed-on fireproofing, and other material used for soundproofing or insulation. ● Lead-Based Paint – LBP

  15. Fabrication of a multi-walled carbon nanotube-deposited glass fiber air filter for the enhancement of nano and submicron aerosol particle filtration and additional antibacterial efficacy.

    PubMed

    Park, Jae Hong; Yoon, Ki Young; Na, Hyungjoo; Kim, Yang Seon; Hwang, Jungho; Kim, Jongbaeg; Yoon, Young Hun

    2011-09-01

    We grew multi-walled carbon nanotubes (MWCNTs) on a glass fiber air filter using thermal chemical vapor deposition (CVD) after the filter was catalytically activated with a spark discharge. After the CNT deposition, filtration and antibacterial tests were performed with the filters. Potassium chloride (KCl) particles (<1 μm) were used as the test aerosol particles, and their number concentration was measured using a scanning mobility particle sizer. Antibacterial tests were performed using the colony counting method, and Escherichia coli (E. coli) was used as the test bacteria. The results showed that the CNT deposition increased the filtration efficiency of nano and submicron-sized particles, but did not increase the pressure drop across the filter. When a pristine glass fiber filter that had no CNTs was used, the particle filtration efficiencies at particle sizes under 30 nm and near 500 nm were 48.5% and 46.8%, respectively. However, the efficiencies increased to 64.3% and 60.2%, respectively, when the CNT-deposited filter was used. The reduction in the number of viable cells was determined by counting the colony forming units (CFU) of each test filter after contact with the cells. The pristine glass fiber filter was used as a control, and 83.7% of the E. coli were inactivated on the CNT-deposited filter.

  16. Task 2.0 - Air Quality Assessment, Control, and Analytical Methods Subtask 2.11 - Lactic Acid FGD Additives From Sugar Beet Wastewater

    SciTech Connect

    Olson, Edwin S

    1998-02-01

    Organic buffers maintain the pH of the scrubber slurry in flue gas desulfurization (FGD) as the SO2 dissolves at the air-liquid interface. Inexpensive acids with an appropriate pKa are required for this application. The pKa of lactic acid (3.86) is between that of the interface and the recirculating slurry and will make soluble calcium ion available in large amounts. Currently lactic acid is somewhat expensive for this use, but this project will develop a new source of inexpensive lactate. Microbial action during the storage and processing of sugar beets forms lactic acid in concentrations as high 14 g/L in the processing water. The concentrations are lower than those occurring in conventional fermentation production of lactic acids, but since a considerable amount of water is involved in the processing of sugar beets in the Red River Valley (1 million gallons/day), a substantial amount of lactic acid or calcium lactate could be recovered as a by- product for use in FGD and other applications.

  17. Conductivity and optical band gaps of polyethylene oxide doped with Li{sub 2}SO{sub 4} salt

    SciTech Connect

    Chapi, Sharanappa Raghu, S. Subramanya, K. Archana, K. Mini, V. Devendrappa, H.

    2014-04-24

    The conductivity and optical properties of Li{sub 2}SO{sub 4} doped polyethylene oxide (PEO) films were studied. The polymer electrolyte films are prepared using solution casting technique. The material phase change was confirmed by X-ray diffraction (XRD) technique. Optical absorption study was conducted using UV- Vis. Spectroscopy in the wavelength range 190–1100nm on pure and doped PEO films. The direct and indirect optical band gaps were found decreased from 5.81–4.51eV and 4.84–3.43eV respectively with increasing the Li{sub 2}SO{sub 4}. The conductivity found to increases with increasing the dopant concentration due to strong hopping mechanism at room temperature.

  18. Measurement of the deposition and fate of {sup 35}SO{sub 2} in a pine plantation

    SciTech Connect

    Gay, D.W.; Murphy, C.E. Jr.

    1988-12-31

    An experiment was carried out to determine the uptake rate and fate of SO{sub 2} absorbed by the forest canopy. The radioactive tracer, {sup 35}S was used. Branches of loblolly pine were exposed to {sup 35}SO{sub 2} in the field with a portable chamber. The exposed branches were excised and a sample of needles was immediately washed with distilled water. The needles and water collected in the field was analyzed for {sup 35}S content. The results indicated that a portion of the {sup 35}S could be washed from the needles and another portion was not removed with a water rinse. The portion that could not be removed by rinsing was absorbed at a rate, and followed patterns of absorption, that suggested that absorption was controlled by stomatal diffusion, and thus was internal. The {sup 35}S that could be removed by rinsing appeared to be surface absorption.

  19. Influence of calcium content of biomass-based materials on simultaneous NOx and SO{sub 2} reduction

    SciTech Connect

    Sarma V. Pisupati; Sumeet Bhalla

    2008-04-01

    Pyrolysis products of biomass (bio-oils) have been shown to cause a reduction in NOx emissions when used as reburn fuels in combustion systems. When these bio-oils are processed with lime, calcium is ion-exchanged and the product is called BioLime. BioLime, when introduced into a combustion chamber, pyrolyzes and produces volatile products that reduce NOx emissions through reburn mechanisms. Simultaneously, calcium reacts with SO{sub 2} to form calcium sulfate and thus reduces SO{sub 2} emissions. This paper reports the characterization of composition and pyrolysis behavior of two BioLime products and the influence of feedstock on pyrolysis products. Thermogravimetric analysis (TGA) and {sup 13}C-CP/MAS NMR techniques were used to study the composition of two biomass-based materials. The composition of the pyrolysis products of BioLime was determined in a laboratory scale flow reactor. The effect of BioLime composition on NOx and SO{sub 2} reduction performance was evaluated in a 146.5 kW pilot-scale, down fired combustor (DFC). The effect of pyrolysis gas composition on NOx reduction is discussed. The TGA weight loss curves of BioLime samples in an inert atmosphere showed two distinct peaks corresponding to the decomposition of light and heavy components of the BioLime and a third distinct peak corresponding to secondary thermal decomposition of char. The study also showed that BioLime sample with lower content of residual lignin derivatives and lower calcium content produced more volatile compounds upon pyrolysis in the combustor and achieved higher NOx reduction (15%). Higher yields of pyrolysis gases increased the NO reduction potential of BioLime through homogeneous gas phase reactions. Calcium in BioLime samples effectively reduced SO{sub 2} emissions (60-85%). 36 refs., 6 figs., 3 tabs.

  20. Low temperature SO{sub 2} removal with solid sorbents in a circulating fluidized bed absorber. Final report

    SciTech Connect

    Lee, S.K.; Keener, T.C.

    1994-10-10

    A novel flue gas desulfurization technology has been developed at the University of Cincinnati incorporating a circulating fluidized bed absorber (CFBA) reactor with dry sorbent. The main features of CFBA are high sorbent/gas mixing ratios, excellent heat and mass transfer characteristics, and the ability to recycle partially utilized sorbent. Subsequently, higher SO{sub 2} removal efficiencies with higher overall sorbent utilization can be realized compared with other dry sorbent injection scrubber systems.

  1. Synergistic effect of flyash and SO{sub 2} on development of cucumber (Cucumis sativus L.) leaf injury

    SciTech Connect

    Tung, G.; McIlveen, W.D.; Jones, R.D.

    1995-10-01

    In a two-factorial experiment, sulfur dioxide alone at concentration of 131 {micro}g/m{sup 3} over long exposures or flyash for either coal or oil combustion alone applied onto cucumber (Cucumis sativus L.) foliage causes no visible injury. However, if both flyash and sulfur dioxide were presented simultaneously, a specific mosaic-chlorosis symptom developed on leaves. A synergistic effect was thus demonstrated. Histopathology of the mosaic-chlorosis symptom was studied. An unusual pattern of tissue abnormally initiated from the collapse of the anticlinal cell walls of the upper epidermal cells and progressed along cell walls into mesophyll tissues. Cellular injury at the lower spongy tissues typical of that caused by SO{sub 2} was also observed. A significant elevation of sulfate-sulfur in the leaves treated with a combination of SO{sub 2} and flyash was demonstrated. Significant interactions between the two factors were found for both injury and sulfur chemistry. This suggests that flyash deposits on the leaf surface play a catalytic role in oxidizing atmospheric sulfur dioxide continuously to form sulfuric acid (H{sub 2}SO{sub 4}) in situ. This acid could infiltrate into mesophyll damage cells and tissues en route.

  2. SO{sub x} and NO{sub x} control in Pyroflow circulating fluidized-bed boilers

    SciTech Connect

    Ganesh, A.; Johnk, C.

    1995-12-31

    Ahlstrom Pyropower offers the most comprehensive experience with Circulating Fluidized-Bed Boiler technology available in the world. There are more than 135 Pyroflow units in operation or under construction worldwide with over 400 unit years of operating experience. All Ahlstrom Pyropower units have met their guarantees including, in some cases, the strictest emission limits. Pyroflow commercial CFB boilers have proven the ability and flexibility to burn a wide variety of low grade fuels economically and still meet stringent environmental requirements. The emission control in CFB boilers is specific to the type of fuel used, since each fuel analysis can vary widely. Sulfur dioxide emissions (SO{sub 2}) from CFB boilers are effectively controlled by means of feeding limestone at predetermined locations in the furnace. NO{sub x} emissions are controlled by staged combustion. NO{sub x} emissions can be controlled furthermore by direct injection of ammonia or urea at furnace outlet. SO{sub 2} and NO{sub x} emissions in Ahlstrom Pyropower CFB boilers have been improved over the years by improved process and design parameters. Data from recently commissioned units are provided. A comparison of SO{sub 2} and NO{sub x} emissions with permitted levels is made.

  3. Direct effects of energy-related air pollutants on plant sexual reproduction. Progress report, February 1, 1981-January 31, 1982

    SciTech Connect

    Ragsdale, H.L.; Murdy, W.H.

    1982-10-07

    Direct effects of SO/sub 2/ and NO/sub 2/ on plant sexual reproduction were studied including essential botanical research into modes of anthesis, pollination, pollen germination and pollen tube growth. Much of the present scientific knowledge of the direct in vivo effects of the major air pollutants, SO/sub 2/ and NO/sub 2/, on plant sexual reproduction is a direct result of studies accomplished under this DOE contract. It is our intention to carry this research forward to include similar assessment of a third major air pollutant, ozone.

  4. Commercial demonstration of the NOXSO SO{sub 2}/NO{sub x} removal flue gas cleanup system. Quarterly technical progress report No. 12, December 1, 1993--February 28, 1994

    SciTech Connect

    1994-12-31

    The NOXSO process is a dry, post-combustion flue gas treatment technology which uses a regenerable sorbent to simultaneously adsorb sulfur dioxide (SO{sub 2}) and nitrogen oxides (NO{sub x}) from the flue gas of a coal-fired utility boiler. In the process, the SO{sub 2} is reduced to sulfur by-product and the NO{sub x} is reduced to nitrogen and oxygen. It is predicted that the process can economically remove 90% of the acid rain precursor gases from the flue gas stream in a retrofit or new facility. The objective of the NOXSO Demonstration Project is to design, construct, and operate a flue gas treatment system utilizing the NOXSO process. The effectiveness of the process will be demonstrated by achieving significant reductions in emissions of sulfur and nitrogen oxides. In addition, sufficient operating data will be obtained to confirm the process economics and provide a basis to guarantee performance on a commercial scale. The project is presently in the project definition and preliminary design phase. Data obtained during pilot plant testing which was completed on July 30, 1993 is being incorporated in the design of the commercial size plant. A suitable host site to demonstrate the NOXSO process on a commercial scale is presently being sought. The plant general arrangement has been revised to incorporate principles used in the design of fluidized catalytic cracking (FCC) plants. A NOXSO plant availability analysis was prepared using operating experience from the recently completed pilot plant as a basis. The impact of water desorption in the sorbent heater and water adsorption in the sorbent cooler has been quantified and incorporated into the NOXSO process simulator. NOXSO process economics has been updated based on the present design. Capital cost for a 500 MW plant designed to remove 98% of the SO{sub 2} and 85% of the NO{sub x} is estimated at $247/kW.

  5. Cross-flow, filter-sorbent catalyst for particulate, SO{sub 2} and NO{sub x} control. Sixth quarterly technical progress report

    SciTech Connect

    Benedek, K.; Flytzani-Stephanopoulos, M.

    1991-08-01

    This report describes a new concept for integrated pollutant control: a cross-flow filter comprised of layered, gas permeable membranes that act a particulate filter, an SO{sub 2} sorbent, and a NO{sub x} reduction catalyst.

  6. Simultaneous SO{sub 2}/NO/N{sub 2}O control in coal fired systems using BioLime{trademark}

    SciTech Connect

    Simons, G.A.; Place, W.J.; Oehr, K.H.; Zhou, J.

    1997-07-01

    BioLime{trademark}, a material comprised of organic calcium salts derived from organic waste (sawdust, municipal solid waste or agricultural waste), is used to simultaneously control SO{sub x}, NO{sub x} and N{sub 2}O emissions from pulverized coal combustion (PCC) and circulating fluidized bed combustion (CFBC) with calcium utilizations greater than 90%, i.e., 90% SO{sub 2} removal at Ca/S=1.

  7. Sorbent preparation/modification/additives. Final report, September 1, 1992--November 30, 1993

    SciTech Connect

    Prudich, M.E.; Venkataramakrishnan, R.

    1994-02-01

    Sorbent preparation techniques used today have generally been adapted from techniques traditionally used by the lime industry. Traditional dry hydration and slaking processes have been optimized to produce materials intended for use in the building industry. These preparation techniques should be examined with an eye to optimization of properties important to the SO{sub 2} capture process. The study of calcium-based sorbents for sulfur dioxide capture is complicated by two factors: (1) little is known about the chemical mechanisms by which the standard sorbent preparation and enhancement techniques work, and (2) a sorbent preparation technique that produces a calcium-based sorbent that enjoys enhanced calcium utilization in one regime of operation [flame zone (>2400 F), in-furnace (1600--2400 F), economizer (800--1100 F), after air preheater (<350 F)] may not produce a sorbent that enjoys enhanced calcium utilization in the other reaction zones. Again, an in-depth understanding of the mechanism of sorbent enhancement is necessary if a systematic approach to sorbent development is to be used. As a long-term goal, an experimental program is being carried out for the purpose of (1) defining the effects of slaking conditions on the properties of calcium-based sorbents, (2) determining how the parent limestone properties of calcium-based sorbents, and (3) elucidating the mechanism(s) relating to the activity of various dry sorbent additives. An appendix contains a one-dimensional duct injection model with modifications to handle the sodium additives.

  8. Estimating the hydrogen ion concentration in concentrated NaCl and Na{sub 2}SO{sub 4} electrolytes

    SciTech Connect

    Rai, D.; Felmy, A.R.; Juracich, S.P.; Rao, F.

    1995-06-01

    Combination glass electrodes were tested for determining H{sup +} concentrations in concentrated pure and mixed NaCl and Na{sub 2}SO{sub 4} solutions, as well as natural brine systems. NaCl, Na{sub 2}SO{sub 4}, and mixtures of NaCl and Na{sub 2}SO{sub 4} solutions were analyzed. Correction factors for estimating pC{sub H}{sup +} (negative logarithm of H{sup +} concentration) were determined from measured/observed pH values. Required Gran-type titrations were done with HCl and/or NaOH. The titration method is described and a step-by-step procedure provided; it has been used previously for determining pC{sub H}{sup +} values of synthetic chloride-dominated brines. Precautions are required to determine correction factors for electrolytes that react with H{sup +} or OH{sup {minus}} [sulfate brines for titration with acid; magnesium brines for titration with base because of precipitation of Mg(OH)2]. Correction factors A (pC{sub H}{sup +} = pH{sub ob} + A) from HCl titrations were similar to those from NaOH titrations where the concentration of free H{sup +} was calculated using a thermodynamic model. These values should be applicable to solns with a very large range in measured pH values (2 to 12). Because a large number of solns were titrated with HCl and the A values are similar for HCl and NaOH titrations, the A values for NaCl and Na2SO4 solns were fit as a function of molality to allow extrapolation. For NaCl solns 0 to 6.0 M, A can be obtained by multiplying the molality by 0.159. For Na2SO4 solns 0 to 2.0 M, the values of A can be obtained from (0.221 {minus} 0.549X + 0.201X{sup 2}), where X is the molality of Na{sub 2}SO{sub 4}. Orion-Ross electrode evaluations indicated that the A values did not differ significantly for different electrodes. Results suggest that the data in this report can be used to estimate A values for different NaCl and Na{sub 2}SO{sub 4} solns even for noncalibrated electrodes.

  9. Control of coal combustion SO{sub 2} and NO{sub x} emissions by in-boiler injection of CMA. First quarterly project status report, 1 October 1992--31 December 1992

    SciTech Connect

    Levendis, Y.A.; Wise, D.L.

    1992-12-31

    The principal objectives of the proposed research are two-fold: (A) To understand the mechanism and assess the effectiveness of sulfur capture by the chemical calcium magnesium acetate (CMA). And (B) To evaluate the NO{sub x} reduction capabilities of CMA by burning the organic constituents of the chemical (the acetate) and reducing NO to stable N{sub 2} The optimum conditions and the location of CMA introduction in the furnace will be identified. To achieve these goals water solutions of CMA or dry powders of CMA will be injected into hot air or gases simulating the furnace exhaust (containing CO{sub 2}, SO{sub x} NO{sub x}, H{sub 2}O, O{sub 2} etc.) and the composition of gaseous and solid products of the reaction will be monitored. The processes of burning the organic acetate as well as the calcination, sintering and sulfation of the remaining solid will be studied in detail.

  10. Dry SO/sub 2/ particulate removal for coal-fired boilers. Volume 2. 22-MW demonstration using nahcolite, trona, and soda ash. Final report

    SciTech Connect

    Muzio, L.J.; Sonnichsen, T.W.

    1984-06-01

    The second phase of a full scale demonstration of the integration of the dry injection of sodium sorbents coupled with a fabric filter baghouse was conducted at Public Service Company of Colorado's Cameo Unit 1, a 22 MW coal-fired utility boiler equipped with an eight compartment baghouse. An initial test series conducted in 1980 had demonstrated the capability of 70% SO/sub 2/ removal with nahcolite injection without significant impact on the baghouse operation. The objectives of the second test series were to expand the evaluation of nahcolite to operation at reduced baghouse temperatures, high temperature injection and varied coal applications, and the use of several alternative and potentially more available sorbent materials. SO/sub 2/ removal was shown to be primarily a function of the type and rate of sorbent injection. The performance of nahcolite was consistent with the previous tests achieving approximately 80% SO/sub 2/ removal with the injection of a stoichiometric amount into the flue gases. Comparable injection quantities of the three trona materials evaluated resulted in 55% SO/sub 2/ removal. Soda ash was ineffective in removing SO/sub 2/ at all injection rates. No significant differences in the SO/sub 2/ removal characteristics of nahcolite were observed while firing coal from several sources. Sorbent injection had no appreciable impact on the baghouse pressure drop characteristics or bag cleanability. Baghouse collection efficiency remained at 99.9+% levels. 3 references, 19 figures, 8 tables.

  11. Food additives

    PubMed Central

    Spencer, Michael

    1974-01-01

    Food additives are discussed from the food technology point of view. The reasons for their use are summarized: (1) to protect food from chemical and microbiological attack; (2) to even out seasonal supplies; (3) to improve their eating quality; (4) to improve their nutritional value. The various types of food additives are considered, e.g. colours, flavours, emulsifiers, bread and flour additives, preservatives, and nutritional additives. The paper concludes with consideration of those circumstances in which the use of additives is (a) justified and (b) unjustified. PMID:4467857

  12. Vinyl capped addition polyimides

    NASA Technical Reports Server (NTRS)

    Vannucci, Raymond D. (Inventor); Malarik, Diane C. (Inventor); Delvigs, Peter (Inventor)

    1991-01-01

    Polyimide resins (PMR) are generally useful where high strength and temperature capabilities are required (at temperatures up to about 700 F). Polyimide resins are particularly useful in applications such as jet engine compressor components, for example, blades, vanes, air seals, air splitters, and engine casing parts. Aromatic vinyl capped addition polyimides are obtained by reacting a diamine, an ester of tetracarboxylic acid, and an aromatic vinyl compound. Low void materials with improved oxidative stability when exposed to 700 F air may be fabricated as fiber reinforced high molecular weight capped polyimide composites. The aromatic vinyl capped polyimides are provided with a more aromatic nature and are more thermally stable than highly aliphatic, norbornenyl-type end-capped polyimides employed in PMR resins. The substitution of aromatic vinyl end-caps for norbornenyl end-caps in addition polyimides results in polymers with improved oxidative stability.

  13. Adipic gets the acid test as flue gas scrubber additive

    SciTech Connect

    Miller, I.R.

    1980-02-11

    The first full-scale demonstration of adipic acid for such use, to be conducted early in the summer of 1980 in a 200 MW power plant burning high-sulfur coal, is designed to clarify the costs and show how to reduce losses of adipic acid via degradation. Adipic acid improves SO/sub 2/ removal by acting as a buffer to limit the pH drop normally occurring at the gas-liquid interface so that the higher SO/sub 2/ concentration in the surface film improves liquid-phase mass transfer; it also promotes higher limestone utilization. Prepared by the Tennessee Valley Authority, a preliminary economic analysis for a 500 MW plant burning 4% sulfur coal indicates that the addition of 1500 ppM of adipic acid (limestone at $7/ton and the acid at $840/ton) would raise SO/sub 2/ removal from 90 to 95%, reduce the total capital investment from $41.5 to $39.5 million, and have a first year revenue requirement of $19.9 million vs. $20.9 million without the acid. The large-scale trial will also help clarify concern over unpleasant odors that have been reported at test sites of the limestone/adipic system; valeric acid has been identified as the cause.

  14. Commercial demonstration of the NOXSO SO{sub 2}/NO{sub x} removal flue gas cleanup system. Quarterly technical progress report No. 9, March 1--May 31, 1993

    SciTech Connect

    1993-12-31

    The NOXSO process is a dry, post-combustion flue gas treatment technology which uses a regenerable sorbent to simultaneously adsorb sulfur dioxide (SO{sub 2}) and nitrogen oxides (NO{sub x}) from the flue gas of a coal-fired utility boiler. In the process, the SO{sub 2} is reduced to elemental sulfur and the NO{sub x} is reduced to nitrogen and oxygen. It is predicted that the process can economically remove 90% of the acid rain precursor gases from the flue gas stream in a retrofit or new facility. The objective of the NOXSO Demonstration Project is to design, construct, and operate a flue gas treatment system utilizing the NOXSO process at Ohio Edison`s Niles Plant Unit {number_sign}1. The effectiveness of the process will be demonstrated by achieving significant reductions in emissions of sulfur and nitrogen oxides. In addition, sufficient operating data will be obtained to confirm the process economics and provide a basis to guarantee performance on a commercial scale. Ohio Edison`s Niles Plant Unit {number_sign}1 generates 115 MW of electricity and 275,000 scfm of flue gas while burning 3.5% sulfur coal. The project is presently in the project definition and preliminary design phase. This phase was included in the project to allow completion of process studies and preliminary activities which could be conducted in parallel with NOXSO`s pilot plant project being conducted at Ohio Edison`s Toronto Power Plant.

  15. Studies on the effect of acid treated TiO{sub 2} on the electrical and tensile properties of hexanoyl chitosan-polystyrene-LiCF{sub 3}SO{sub 3} composite polymer electrolytes

    SciTech Connect

    Hanif, Nur Shazlinda Muhammad; Shahril, Nur Syuhada Mohd; Azmar, Amisha; Winie, Tan

    2015-08-28

    Composite polymer electrolytes (CPEs) comprised of hexanoyl chitosan:polystyrene (90:10) blend, lithium triflouromethanesulfonate (LiCF{sub 3}SO{sub 3}) salt and titanium oxide (TiO{sub 2}) filler were prepared by solution casting technique. The TiO{sub 2} fillers were treated with 2% sulphuric acid (H{sub 2}SO{sub 4}) aqueous solution. The effect of acid treated TiO{sub 2} on the electrical and tensile properties of the electrolytes were investigated. Acid treated TiO{sub 2} decreased the electrolyte conductivity. Both the dielectric constant and dielectric loss decrease with increasing frequency and increases with increasing temperature. Relaxation times for ionic carriers were extracted from the loss tangent maximum peak at various temperatures. A distribution of relaxation time implied the non-Debye response. At all frequencies, ac conductivity increases with increasing temperature. An enhancement in the Young’s modulus was observed with the addition of TiO{sub 2}. The Young’s modulus increases with increasing TiO{sub 2} content. This is discussed using the percolation concept.

  16. Implications of the Clean Air Act acid rain title on industrial boilers

    SciTech Connect

    Maibodi, M. )

    1991-11-01

    This paper discusses the impacts of the 1990 Clean Air Act Amendments related to acid rain controls, as they apply to industrial boilers. Emphasis is placed on explaining the Title IV provisions of the Amendments that permit nonutility sources to participate in the SO{sub 2} allowance system. The allowance system, as it pertains to industrial boiler operators, is described, and the opportunities for operators to trade and/or sell SO{sub 2} emission credits is discussed. The paper also reviews flue gas desulfurization system technologies available for industrial boiler operators who may choose to participate in the system. Furnace sorbent injection, advanced silicate process, lime spray drying, dry sorbent injection, and limestone scrubbing are described, including statements of their SO{sub 2} removing capability, commercial status, and costs. Capital costs, levelized costs and cost-effectiveness are presented for these technologies.

  17. Food additives

    MedlinePlus

    ... or natural. Natural food additives include: Herbs or spices to add flavor to foods Vinegar for pickling ... Certain colors improve the appearance of foods. Many spices, as well as natural and man-made flavors, ...

  18. PHOTOCHEMISTRY IN TERRESTRIAL EXOPLANET ATMOSPHERES. II. H{sub 2}S AND SO{sub 2} PHOTOCHEMISTRY IN ANOXIC ATMOSPHERES

    SciTech Connect

    Hu Renyu; Seager, Sara; Bains, William

    2013-05-20

    Sulfur gases are common components in the volcanic and biological emission on Earth, and are expected to be important input gases for atmospheres on terrestrial exoplanets. We study the atmospheric composition and the spectra of terrestrial exoplanets with sulfur compounds (i.e., H{sub 2}S and SO{sub 2}) emitted from their surfaces. We use a comprehensive one-dimensional photochemistry model and radiative transfer model to investigate the sulfur chemistry in atmospheres ranging from reducing to oxidizing. The most important finding is that both H{sub 2}S and SO{sub 2} are chemically short-lived in virtually all types of atmospheres on terrestrial exoplanets, based on models of H{sub 2}, N{sub 2}, and CO{sub 2} atmospheres. This implies that direct detection of surface sulfur emission is unlikely, as their surface emission rates need to be extremely high (>1000 times Earth's volcanic sulfur emission) for these gases to build up to a detectable level. We also find that sulfur compounds emitted from the surface lead to photochemical formation of elemental sulfur and sulfuric acid in the atmosphere, which would condense to form aerosols if saturated. For terrestrial exoplanets in the habitable zone of Sun-like stars or M stars, Earth-like sulfur emission rates result in optically thick haze composed of elemental sulfur in reducing H{sub 2}-dominated atmospheres for a wide range of particle diameters (0.1-1 {mu}m), which is assumed as a free parameter in our simulations. In oxidized atmospheres composed of N{sub 2} and CO{sub 2}, optically thick haze, composed of elemental sulfur aerosols (S{sub 8}) or sulfuric acid aerosols (H{sub 2}SO{sub 4}), will form if the surface sulfur emission is two orders of magnitude more than the volcanic sulfur emission of Earth. Although direct detection of H{sub 2}S and SO{sub 2} by their spectral features is unlikely, their emission might be inferred by observing aerosol-related features in reflected light with future generation space

  19. Microbial reduction of SO{sub 2} and NO{sub x} as a means of by-product recovery/disposal from regenerable processes for the desulfurization of flue gas. Technical progress report, March 11, 1993--June 11, 1993

    SciTech Connect

    Sublette, K.L.

    1993-11-01

    There are two basic approaches to addressing the problem of SO{sub 2} and NO{sub x} emissions: (1) desulfurize (and denitrogenate) the feedstock prior to or during combustion; or (2) scrub the resultant SO{sub 2} and oxides of nitrogen from the boiler flue gases. The flue gas processing alternative has been addressed in this project via microbial reduction of SO{sub 2} and NO{sub x} by sulfate-reducing bacteria

  20. A first principles study on the solvation and structure of SO{sub 4}{sup 2-}(H{sub 2}O){sub n}, n=6-12

    SciTech Connect

    Gao Bing; Liu Zhifeng

    2004-11-01

    The structures of hydrated sulfate clusters, SO{sub 4}{sup 2-}(H{sub 2}O){sub n} with n=6-12, are obtained by density functional theory calculations. For SO{sub 4}{sup 2-}(H{sub 2}O){sub 12}, two structures with symmetric distribution of H{sub 2}O molecules around the sulfate group are favored in energy. The structures for the smaller clusters, SO{sub 4}{sup 2-}(H{sub 2}O){sub n} with n=6-11, are obtained by taking away one H{sub 2}O molecule successively from the two symmetric SO{sub 4}{sup 2-}(H{sub 2}O){sub 12} isomers. The hydrogen bonding between the sulfate O atoms and H{sub 2}O molecules are strong. So are the hydrogen bonds among H{sub 2}O molecules, which are facilitated by the structure of the polyatomic sulfate group. The solvation energy is quite large (often exceeding 15 kcal/mol). The patterns for structural and energy changes as the cluster size increases are very different from the well studied hydrated halide ions, although the competition between solute-solvent and solvent-solvent interactions is again an important factor. Ab initio molecular dynamics simulations also show 'crowding' effects in the first solvation of SO{sub 4}{sup 2-}(H{sub 2}O){sub 12} at raised temperature.

  1. Method for sequestering CO.sub.2 and SO.sub.2 utilizing a plurality of waste streams

    DOEpatents

    Soong, Yee; Allen, Douglas E.; Zhu, Chen

    2011-04-12

    A neutralization/sequestration process is provided for concomitantly addressing capture and sequestration of both CO.sub.2 and SO.sub.2 from industrial gas byproduct streams. The invented process concomitantly treats and minimizes bauxite residues from aluminum production processes and brine wastewater from oil/gas production processes. The benefits of this integrated approach to coincidental treatment of multiple industrial waste byproduct streams include neutralization of caustic byproduct such as bauxite residue, thereby decreasing the risk associated with the long-term storage and potential environmental of storing caustic materials, decreasing or obviating the need for costly treatment of byproduct brines, thereby eliminating the need to purchase CaO or similar scrubber reagents typically required for SO.sub.2 treatment of such gasses, and directly using CO.sub.2 from flue gas to neutralize bauxite residue/brine mixtures, without the need for costly separation of CO.sub.2 from the industrial byproduct gas stream by processes such as liquid amine-based scrubbers.

  2. Magmatic gas source for the stratospheric SO[sub 2] cloud from the June 15, 1991, eruption of Mount Pinatubo

    SciTech Connect

    Westrich, H.R. ); Gerlach, T.M. )

    1992-10-01

    A water-rich magmatic gas phase escaped explosively from Mount Pinatubo on June 15, 1991, taking with it a load of crystalline and molten material sufficient to form pumice and tephra deposits with an estimated total dense-rock-equivalent volume of 3-5 km[sup 3], and carrying in it enough sulfur to form a 20 Mt SO[sub 2] cloud in the stratosphere. Application of the petrologic method for estimating sulfur degassing during the climatic event from the sulfur content of trapped glass inclusions and matrix glasses in the pumice deposits requires an unacceptably large volume of erupted magma to account for SO[sub 2] in the stratospheric cloud. The ubiquitous presence of primary vapor bubbles in glass inclusions and unaltered anhydrite phenocrysts in the pumice suggest that sulfur was present in a separate H[sub 2]O-rich gas phase of the Pinatubo magma before eruption. Thus, for this eruption, and perhaps others, the petrologic method for estimating sulfur degassing is prone to substantial underestimation of sulfur release and the potential climatic impact of past explosive eruptions.

  3. Nanocrystalline K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3}: Eu for proton beam dosimetry

    SciTech Connect

    Bahl, Shaila; Lochab, S. P.; Pandey, A.; Aleynikov, V. E.; Molokanov, A.; Kumar, Pratik

    2012-06-05

    This paper investigates the Thermoluminescent response of nanocrystalline K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3}: Eu, prepared by Co-precipitation technique to 150 MeV proton beam. The particle size was calculated to be 45 nm by the broadening of the XRD peaks using Scherrer's formula. Samples in the form of pellets were irradiated by 150 MeV proton beam with dose range of 0.1 Gy to 325 Gy. Thermoluminescence (TL) glow curves of the irradiated samples were recorded and studied. It has been found that the phosphor shows a characteristic single peak at around 420 K. The TL response is linear in the range upto 200 Gy and then saturates for higher doses. The wider linear TL response of nanocrystalline K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3}: Eu and low fading makes it a superior candidate as a dosimeter to be used for detecting the doses of protons beams for its various applications in the field of space, therapy and research.

  4. Potlining Additives

    SciTech Connect

    Rudolf Keller

    2004-08-10

    In this project, a concept to improve the performance of aluminum production cells by introducing potlining additives was examined and tested. Boron oxide was added to cathode blocks, and titanium was dissolved in the metal pool; this resulted in the formation of titanium diboride and caused the molten aluminum to wet the carbonaceous cathode surface. Such wetting reportedly leads to operational improvements and extended cell life. In addition, boron oxide suppresses cyanide formation. This final report presents and discusses the results of this project. Substantial economic benefits for the practical implementation of the technology are projected, especially for modern cells with graphitized blocks. For example, with an energy savings of about 5% and an increase in pot life from 1500 to 2500 days, a cost savings of $ 0.023 per pound of aluminum produced is projected for a 200 kA pot.

  5. Phosphazene additives

    DOEpatents

    Harrup, Mason K; Rollins, Harry W

    2013-11-26

    An additive comprising a phosphazene compound that has at least two reactive functional groups and at least one capping functional group bonded to phosphorus atoms of the phosphazene compound. One of the at least two reactive functional groups is configured to react with cellulose and the other of the at least two reactive functional groups is configured to react with a resin, such as an amine resin of a polycarboxylic acid resin. The at least one capping functional group is selected from the group consisting of a short chain ether group, an alkoxy group, or an aryloxy group. Also disclosed are an additive-resin admixture, a method of treating a wood product, and a wood product.

  6. Portland cement for SO/sub 2/ control in coal-fired power plants

    DOEpatents

    Steinberg, M.

    1984-10-17

    A method is described for removing oxides of sulfur from the emissions of fossil fuel combustion by injecting portland cement into the boiler with the fuel, the combustion air, or downstream with the combustion gases. The cement products that result from this method is also described. 1 tab.

  7. Portland cement for SO.sub.2 control in coal-fired power plants

    DOEpatents

    Steinberg, Meyer

    1985-01-01

    There is described a method of removing oxides of sulfur from the emissions of fossil fuel combustion by injecting portland cement into the boiler with the fuel, the combustion air, or downstream with the combustion gases. There is also described the cement products that result from this method.

  8. Catalytic reduction of SO{sub 2} with methane over molybdenum catalyst. Quarterly technical report, September 1, 1994--November 30, 1994

    SciTech Connect

    Wiltowski, T.

    1995-03-01

    One of the primary concerns in coal utilization is the emission of sulfur compounds, especially SO{sub 2}. This project deals with catalytic reduction of SO{sub 2} with methane using molybdenum sulfide catalyst supported on different activated carbons: Darco TRS, Norit ROZ-3, and an activated carbon prepared from Illinois coal IBC-110. The work conducted during this quarter has concentrated on catalyst preparation and characterization along with synthesis of activated carbon from IBC-110 coal, as well as, construction of the apparatus for catalytic tests of SO{sub 2} reduction with methane. It was found that Darco TRS supported catalysts have larger surface area than the pure activated carbon, whereas the impregnation of Norit ROZ-3 did not significantly change the BET surface area. Also, the synthesis of activated carbon support from IBC-110 is in progress.

  9. [Surface study of absorbents for the removal of SO{sub x} and NO{sub x}]. Quarterly report, September 1, 1990--November 30, 1990

    SciTech Connect

    Cooper, B.R.; Montano, P.

    1990-12-31

    XANES spectra are given for a number of model sulfur-containing compounds. The XANES and EXAFS spectra and structures of the inorganic standards (CuSO{sub 4}, FeS{sub 2}, FeS, CuS) are discussed. Calculations were made on SO{sub 2} adsorption on CuO/Al{sub 2}O{sub 3} surface; results show that the SO{sub 2} is adsorbed on the surface via O-Cu bonding, probably in the form of a ``bridge`` with the two oxygen atoms of SO{sub 2}sitting at two surface metal atoms. It is probably better to have low-temperature adsorption in reusable adsorbents because of the lower bonding energy of the O-Cu bonding. The possibility of adsorption at the edge or corner of the material is considered.

  10. Combined removal of SO{sub x} and NO{sub x} from flue gas using non-thermal plasma. [Quarterly] technical report, September 1--November 30, 1994

    SciTech Connect

    Dhali, S.K.

    1994-12-31

    The SO{sub 2} removal efficiency was studied for concentration in the range of 333--3000 ppM (parts per million). Since the sulfur content of Illinois coal is high, the SO{sub 2} concentration in typical flue gas is in the high end of the range shown above. With high concentration of SO{sub 2} the removal efficiency decreases. However, the removal scales well with applied voltage, electrode length, and supply frequency. In this period the modeling of the process was also accomplished. The results show that a Townsend-type discharge is more efficient than a streamer type discharge in producing OH and 0 radicals. This explains why UV-irradiation helps the removal efficiency. The details are discussed in the report.

  11. Corrosion behavior of carbon steel in the monoethanolamine-H{sub 2}O-CO{sub 2}-O{sub 2}-SO{sub 2} system

    SciTech Connect

    Kladkaew, N.; Idem, R.; Tontiwachwuthikul, P.; Saiwan, C.

    2009-10-15

    The effects of operating parameters on the corrosion of carbon steel in the monoethanolamine (MEA)-H{sub 2}O-CO{sub 2}-O{sub 2}-SO{sub 2} system were investigated using two different corrosion measurement techniques. The corrosion studies were conducted using a 273A potentiostat using MEA, O{sub 2}, and SO{sub 2} concentrations and CO{sub 2} loading in the ranges of 1-7 kmol/m{sup 3}, 0-100%, 0-204 ppm, and 0-0.5 mol CO{sub 2}/mol MEA, respectively, at corrosion temperatures in the range of 303-353 K. The experimental results showed, for the first time, that a higher concentration of SO{sub 2} in a simulated flue gas stream induces a higher corrosion rate essentially because of the increase in the hydrogen ion concentration generated by reactions of SO{sub 2} and H{sub 2}O as well as SO{sub 2}, O{sub 2}, and H{sub 2}O. Also, an increase in oxygen concentration in the simulated flue gas stream causes a higher corrosion rate due to the increasing solubility of oxygen and, in turn, a higher amount of dissolved oxygen in the liquid phase. The results further show that an increase in the concentrations of MEA, O{sub 2}, and SO{sub 2} as well as CO{sub 2} loading will cause the generation of higher amounts of hydrogen or hydronium ions, as well as carbonic acid and bicarbonate ions, and this is what leads to a higher corrosion rate.

  12. Effects of HCl and SO{sub 2} concentration on mercury removal by activated carbon sorbents in coal-derived flue gas

    SciTech Connect

    Ryota Ochiai; M. Azhar Uddin; Eiji Sasaoka; Shengji Wu

    2009-09-15

    The effect of the presence of HCl and SO{sub 2} in the simulated coal combustion flue gas on the Hg{sup 0} removal by a commercial activated carbon (coconut shell AC) was investigated in a laboratory-scale fixed-bed reactor in a temperature range of 80-200{sup o}C. The characteristics (thermal stability) of the mercury species formed on the sorbents under various adsorption conditions were investigated by the temperature-programmed decomposition desorption (TPDD) technique. It was found that the presence of HCl and SO{sub 2} in the flue gas affected the mercury removal efficiency of the sorbents as well as the characteristics of the mercury adsorption species. The mercury removal rate of AC increased with the HCl concentration in the flue gas. In the presence of HCl and the absence of SO{sub 2} during Hg{sup 0} adsorption by AC, a single Hg{sup 0} desorption peak at around 300{sup o}C was observed in the TPDD spectra and intensity of this peak increased with the HCl concentration during mercury adsorption. The peak at around 300{sup o}C may be derived from the decomposition and desorption of mercury chloride species. The presence of SO{sub 2} during mercury adsorption had an adverse effect on the mercury removal by AC in the presence of HCl. In the presence of both HCl and SO{sub 2} during Hg{sup 0} adsorption by AC, the major TPDD peak temperatures changed drastically depending upon the concentration of HCl and SO{sub 2} in flue gas during Hg{sup 0} adsorption. 16 refs., 7 figs.

  13. Analysis of SO{sub 2} sorption capacity of rice husk ash (RHA)/CaO/NaOH sorbents using response surface methodology (RSM): untreated and pretreated RHA

    SciTech Connect

    Irvan Dahlan; Keat Teong Lee; Azlina Harun Kamaruddin; Abdul Rahman Mohamed

    2008-03-01

    The SO{sub 2} sorption capacity (SSC) of sorbents prepared from rice husk ash (RHA) with NaOH as additive was studied in a fixed-bed reactor. Rice husk ash is produced by burning rice husks at about 300{sup o}C and was chosen as a source of siliceous material, abundantly available in Malaysia. The sorbents were prepared using a water hydration method by slurrying RHA, CaO, and NaOH. Response surface methodology (RSM) based on four-variable central composite face centered design (CCFCD) was employed in the synthesis of the sorbents. The correlation between the sorbent SSC (as response) with four independent sorbent preparation variables, i.e. hydration period, RHA/CaO ratio, NaOH amount, and drying temperature, were presented as empirical mathematical models. Among all the variables studied, the amount of NaOH used was found to be the most significant variable affecting the SSC of the sorbents prepared. The SSC for sorbent prepared with the addition of NaOH was found to be significantly higher than sorbents prepared without NaOH. This is probably because NaOH is a deliquescent material, and its existence increases the amount of water collected on the surface of the sorbent, a condition required for sorbent-SO{sub 2} reaction to occur at low temperature. The effect of further treatment of RHA at 600{sup o}C was also investigated. Although pretreated RHA sorbents demonstrated higher SSC as compared to untreated RHA sorbents, nevertheless, at optimum conditions, sorbents prepared from untreated RHA was found to be more favorable due to practical and economic concerns. 33 refs., 3 figs., 1 tab.

  14. Influence of different additives on the reaction between hydrated lime and sulfur dioxide

    SciTech Connect

    Cunill, F.; Izquierdo, J.F.; Martinez, J.C.; Tejero, J.; Querol, J. )

    1991-11-01

    Five commercial calcium hydroxides were tested in a fixed-bed reactor for SO{sub 2} removal at bag-filter conditions. Small amounts of different additives (fly ash, NaOH, NaCl and CaCl{sub 2}) were added to the commercial Ca(OH){sub 2} which showed the greatest reactivity respect to SO{sub 2} (by a drying process). Fly ash performance was negative whereas the rest of additives enhanced the desulfurization power of the Ca(OH){sub 2}, specially NaOH (due to its basic and deliquescent character) and CaCl{sub 2} (by its delilquescence). CaCl{sub 2} has been the best additive tested at the used experimental conditions.

  15. 75 FR 81235 - Procurement List; Addition

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-27

    ... Attendant, Pease Air National Guard Base, Newington, NH. Comments on the proposed addition were received... added to the Procurement List: Service Service Type/Location: Food Service Attendant, Pease Air...

  16. Why an SO/sub 2/ emission tax is an unpopular policy instrument: Simulation results from a general equilibrium model of the Norwegian economy

    SciTech Connect

    Hanson, D.A.; Alfsen, K.H.

    1986-01-01

    Norway, together with some twenty other countries, signed the Helsinki treaty in July 1985 for the purpose of reducing SO/sub 2/ emissions. Hence, it is interesting to analyze the emission reductions that could be achieved using a tax on SO/sub 2/ emissions, as well as the indirect impacts on the economy. Simulations of the economic impact of the tax (which effectively increases the cost of using energy) were made using the Multi-Sectoral Growth (MSG) model. Results of the simulations indicated a larger than expected reduction in economic output.

  17. Does weather confound or modify the association of particulate air pollution with mortality? An analysis of the Philadelphia data, 1973--1980

    SciTech Connect

    Samet, J.; Zeger, S.; Kelsall, J.; Xu, J.; Kalkstein, L.

    1998-04-01

    This report considers the consequences of using alternative approaches to controlling for weather and explores modification of air pollution effects by weather, as weather patterns could plausibly alter air pollution`s effect on health. The authors analyzed 1973--1980 total mortality data for Philadelphia using four weather models and compared estimates of the effects of TSP and SO{sub 2} on mortality using a Poisson regression model. Two synoptic categories developed by Kalkstein were selected--The Temporal Synoptic Index (TSI) and the Spatial Synoptic Classification (SSC)--and compared with (1) descriptive models developed by Schwartz and Dockery (S-D); and (2) LOESS, a nonparametric function of the previous day`s temperature and dew point. The authors considered model fit using Akaike`s Information Criterion (AIC) and changes in the estimated effects of TSP and SO{sub 2}. In the full-year analysis, S-D is better than LOESS at predicting mortality, and S-D and LOESS are better than TSI, as measured by AIC. When TSP or SO{sub 2} was fit alone, the results were qualitatively similar, regardless of how weather was controlled; when TSP and SO{sub 2} were fit simultaneously, the S-D and LOESS models give qualitatively different results than TSI, which attributes more of the pollution effect to SO{sub 2} than to TSP. Model fit is substantially poorer with TSI.

  18. Syntheses, crystal structures and optical spectroscopy of Ln{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O (Ln=Ho, Tm) and Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O

    SciTech Connect

    Kazmierczak, Karolina; Hoeppe, Henning A.

    2011-05-15

    The lanthanide sulphate octahydrates Ln{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O (Ln=Ho, Tm) and the respective tetrahydrate Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O were obtained by evaporation of aqueous reaction mixtures of trivalent rare earth oxides and sulphuric acid at 300 K. Ln{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O (Ln=Ho, Tm) crystallise in space group C2/c (Z=4, a{sub Ho}=13.4421(4) A, b{sub Ho}=6.6745(2) A, c{sub Ho}=18.1642(5) A, {beta}{sub Ho}=102.006(1) A{sup 3} and a{sub Tm}=13.4118(14) A, b{sub Tm}=6.6402(6) A, c{sub Tm}=18.1040(16) A, {beta}{sub Tm}=101.980(8) A{sup 3}), Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O adopts space group P2{sub 1}/n (a=13.051(3) A, b=7.2047(14) A, c=13.316(3) A, {beta}=92.55(3) A{sup 3}). The vibrational and optical spectra of Ho{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O and Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O are also reported. -- Graphical abstract: In the lanthanide sulphate octahydrates the cations form slightly undulated layers. Between the layers are voids in which sulphate tetrahedra and water molecules are located. The holmium compound exhibits an Alexandrite effect. Display Omitted Highlights: {yields} Determination of the optimum conditions for the growth of single-crystals of Ln{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O (Ln=Ho, Tm) and Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O. {yields} Single-crystal structure elucidation of Ln{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O (Ln=Ho, Tm) including hydrogen bonds. {yields} Single-crystal structure determination of Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O including hydrogen bonds. {yields} UV-vis spectra of Ho{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O and Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O recorded and interpreted: Assignation of bands and clarification of the Alexandrite effect of the Ho compound. {yields} IR and Raman spectra of Ln{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O (Ln=Ho, Tm) and Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O recorded and interpreted.

  19. Scavenging ratios based on inflow air concentrations

    SciTech Connect

    Davis, W.E.; Dana, M.T.; Lee, R.N.; Slinn, W.G.N.; Thorp, J.M.

    1991-07-01

    Scavenging ratios were calculated from field measurements made during April 1985. Event precipitation samples were collected at the surface, but air chemistry measurements in the air mass feeding the precipitation were made from an aircraft. In contrast, ratios calculated in previous studies have used air concentration and precipitation chemistry data from only surface measurements. Average scavenging ratios were calculated for SO{sub 4}{sup 2{minus}}, NO{sub 3}{sup {minus}}, NH{sub 4}{sup +}, total sulfate, total nitrate, and total ammonium for 5 events; the geometric mean of these scavenging ratios were 8.5 {times} 10{sup 5}, 5.6 {times} 10{sup 6}, 4.3 {times} 10{sup 5}, 3.4 {times} 10{sup 5}, 2.4 {times} 10{sup 6}, and 9.7 {times} 10{sup 4}, respectively. These means are similar to but less variable than previous ratios formed using only surface data.

  20. Measurement of formaldehyde in clean air

    SciTech Connect

    Neitzert, V.; Seiler, W.

    1981-01-01

    A method for the measurement of small amounts of formaldehyde in air has been developed. The method is based on the derivatization of HCHO with 2.4-Denetrophenylhydragine, forming 2.4-Dentrophylhydragine, measured with GC-ECD-technique. HCHO is preconcentrated using a cryogenic sampling technique. The detection limit is 0.05 ppbv for a sampling volume of 200 liter. The method has been applied for measurements in continental and marine air masses showing HCHO mixing ratios of 0.4--5.0 ppbv and 0.2--1.0 ppbv, respectively. HCHO mixing ratios show diurnal variations with maximum values during the early afternoon and minimum values during the early morning. In continental air, HCHO mixing ratios are positively correlated with CO and SO/sub 2/, indicating anthropogenic HCHO sources which are estimated to be 6--11 x 10/sup 12/g/year/sup -1/ on a global scale.

  1. Improving urban air quality in China: Beijing case study

    SciTech Connect

    Jiming Hao; Litao Wang

    2005-09-01

    China is undergoing rapid urbanization because of unprecedented economic growth. As a result, many cities suffer from air pollution. Two-thirds of China's cities have not attained the ambient air quality standards applicable to urban residential areas (Grade II). Particulate matter (PM), rather than sulfur dioxide (SO{sub 2}), is the major pollutant reflecting the shift from coal burning to mixed source pollution. In 2002, 63.2 and 22.4% of the monitored cities have PM and SO{sub 2} concentrations exceeding the Grade II standard, respectively. Nitrogen oxides (NOx) concentration kept a relatively stable level near the Grade II standard in the last decade and had an increasing potential in recent years because of the rapid motorization. In general, the air pollutants emission did not increase as quickly as the economic growth and energy consumption, and air quality in Chinese cities has improved to some extent. Beijing, a typical representative of rapidly developing cities, is an example to illustrate the possible options for urban air pollution control. Beijing's case provides hope that the challenges associated with improving air quality can be met during a period of explosive development and motorization. 21 refs., 19 figs., 6 tabs.

  2. Effects of the 1990 Clean Air Act Amendments

    SciTech Connect

    Hanson, D.A.

    1992-01-01

    At Argonne National Laboratory, we have a great deal of interest in the coal resource and in Clean Coal Technology, CCT. We had helped to develop dry scrubbing technology and we are currently active in developing Integrated Gasification Combined Cycle (IGCC) and combined SO[sub 2] and NO[sub x] removal technologies. I have spent much of the last 10 years developing computer simulation models representing the impacts of environmental policies on electric utilities, the coal industry and the economy as a whole. This work has been sponsored by the National Acid Precipitation Assessment Program (NA.PAP), the US Departmentof Energy, the US Environmental Protection Agency and the Federal Reserve Bank. Today I will talk about the 1990 Clean Air Act Amendments (CAAA) which will affect the coal market. I will focus on the sulfur dioxide (SO[sub 2]) requirements and not nitrogen oxides (NO[sub x]) or other aspects of the CAAA regulations.

  3. Effects of the 1990 Clean Air Act Amendments

    SciTech Connect

    Hanson, D.A.

    1992-12-31

    At Argonne National Laboratory, we have a great deal of interest in the coal resource and in Clean Coal Technology, CCT. We had helped to develop dry scrubbing technology and we are currently active in developing Integrated Gasification Combined Cycle (IGCC) and combined SO{sub 2} and NO{sub x} removal technologies. I have spent much of the last 10 years developing computer simulation models representing the impacts of environmental policies on electric utilities, the coal industry and the economy as a whole. This work has been sponsored by the National Acid Precipitation Assessment Program (NA.PAP), the US Departmentof Energy, the US Environmental Protection Agency and the Federal Reserve Bank. Today I will talk about the 1990 Clean Air Act Amendments (CAAA) which will affect the coal market. I will focus on the sulfur dioxide (SO{sub 2}) requirements and not nitrogen oxides (NO{sub x}) or other aspects of the CAAA regulations.

  4. Studies on the effect of Li{sub 2}SO{sub 4} on the structure of lithium borate glasses

    SciTech Connect

    Ganguli, M.; Rao, K.J.

    1999-02-11

    Thermal and spectroscopic investigations have been carried out on a number of glasses with a wide range of compositions in the pseudoternary glass system, Li{sub 2}SO{sub 4}-Li{sub 2}O-B{sub 2}O{sub 3}, to understand the role of sulfate ions in modifying the borate glass structure. Both nuclear magnetic resonance (NMR) and infrared (IR) spectroscopic results indicate that four-coordinate boron atoms are retained in the glass structure to a greater extent in sulfate-containing glasses than in pure lithium borate glasses. There seems to be some evidence for the existence of sulfoborate-type units in Raman spectra in the region of 800--960 cm{sup {minus}1}. These conclusions are supported by the observed behavior of glass transition temperatures and molar volumes. The possibility of formation of sulfoborate-type units is discussed from bonding and thermodynamic points of view.

  5. Forecasting effects of SO/sub 2/ pollution on growth and succession in a western conifer forest

    SciTech Connect

    Kercher, J.R.; Axelrod, M.C.; Bingham, G.E.

    1980-06-18

    A simulator has been developed for the mixed conifer forest type of the Sierra Nevada, California to forecast the effects of SO/sub 2/ on forest growth and succession. The model simulates recruitment, growth, and death of each tree and is based on a northeastern USA simulator with extensive modifications. These modifications include the introduction of fire ecology, temporal seed crop patterns unique to the Sierra, and water stress. Pollutant stress is modeled as an effect on tree growth. The model simulates the shift from the ponderosa pine dominated forest type to the white fir dominated mixed conifer type as elevation increases from 5000 to 6000 ft. It also simulates the fire-suppression of white fir and the fire-climax of ponderosa pine. For a 10% growth reduction of ponderosa pine from pollutant stress and with growth reductions in other species as determined by their relative sensitivities, standing crops of ponderosa pine were reduced and white fir increased.

  6. Method for simultaneously removing SO.sub.2 and NO.sub.X pollutants from exhaust of a combustion system

    DOEpatents

    Levendis, Yiannis A.; Wise, Donald L.

    1994-05-17

    A method is disclosed for removing pollutants from the exhaust of combustion systems burning fuels containing substantial amounts of sulfur and nitrogen. An exemplary method of the invention involves the formation and reaction of a sorbent comprising calcium magnesium acetate (CMA). The CMA is either dry-sprayed (in the form of a fine powder) or wet-sprayed in an aqueous solution in a high temperature environment such as a combustion chamber. The latter technique is feasible since CMA is a uniquely water-soluble form of calcium and magnesium. When the dispersed particles of CMA are heated to a high temperature, fine calcium and magnesium oxide particles, which are hollow with thin and highly porous walls are formed, affording optimum external and internal accessibility for reacting with toxic gaseous emissions such as SO.sub.2. Further, the combustion of the organic acetate portion of the sorbent results in the conversion of NO.sub.x to N.sub.2.

  7. Reduction of HCl, SO{sub 2} and NO{sub x} emissions of powerplants using organic salts of calcium

    SciTech Connect

    Levendis, Y.A.; Courtemanch, B.; Steciak, J.; Wise, D.L.

    1998-04-01

    Results from laboratory investigations are described that show the benefits in using organic salts of calcium to control emissions of powerplants. These salts include calcium formate (CF, Ca(COOH){sub 2}), calcium acetate (CA, Ca(CH{sub 2}COOH){sub 2}), calcium magnesium acetate (CMA, CaMg{sub 2}(CH{sub 2}COOH){sub 6}), calcium propionate (CP, Ca(CH{sub 2}CH{sub 2}COOH){sub 2}) and calcium benzoate (CB, Ca(C{sub 6}H{sub 4}COOH){sub 2})- Such calcium-containing chemicals are sprayed in the post-combustion region of furnaces to control emissions of SO{sub 2}, HCl and NO{sub x}.

  8. Thermodynamic Model for the Solubility of Ba(SeO4, SO>4) Precipitates

    SciTech Connect

    Rai, D.; Felmy, Andrew R.; Moore, Dean A.; Kitamura, Akira; Yoshikawa, Hideki; Doi, Reisuke; Yoshida, Yasushi

    2014-08-15

    The solubility of Ba(SeO4, SO>4) precipitates was determined as a function of the BaSeO4 mole fractions, ranging from 0.0015 to 0.3830, and time with an equilibration period extending to as long as 302 days. Equilibrium/steady state conditions in this system are reached in ≤ 65 days. Pitzer’s ion interaction model was used to calculate solid and aqueous phase activity coefficients. Thermodynamic analyses showed that the data do not satisfy Gibbs-Duhem equation, thereby demonstrating that a single-solid solution phase does not control both the selenate and sulfate concentrations. Our extensive data with log 10 [Ba] ranging from -3.6 to -5.9 mol kg-1, log 10 [SeO4] rangingfrom-3.6 to -5.2 mol kg-1, and log 10 [SO>4] ranging from-4.0 to -5.3 mol kg-1 can be explained with the formation of an ideal BaSeO4 solid solution phase that controls the selenium concentrations and a slightly disordered/less-crystalline BaSO4(s) (log 10Κ°sp = -9.5 instead of -10.05 for barite) that controls the sulfate concentrations. In these experiments the BaSO4 component of the solid solution phase never reaches thermodynamic equilibrium with the aqueous phase. Thermodynamic interpretations of the data show that both the ideal BaSeO4 solid solution phase and less-crystalline BaSO4 (s) phase are in equilibrium with each other in the entire range of BaSeO4 mole fractions investigated in this study.

  9. SO{sub 2} and NOx trading markets: providing flexibility and results

    SciTech Connect

    Sam Napolitano; Melanie LaCount; Daniel Chartier

    2007-06-15

    Experience with the Acid Rain and NOx Budget Trading Programs demonstrates that cap-and-trade programs are an effective means of achieving broad improvements in air quality. Results demonstrate that the combination of mandatory emissions caps, a viable allowance trading market, rigorous emissions monitoring and reporting protocols, and automatic enforcement provide accountability and ensure results in a cost-effective manner. The market developments discussed in this article demonstrate a successful environmental partnership. With a government focused on results and a private sector motivated to innovate, cap-and trade systems deliver environmental results as efficiently and effectively as possible. 3 refs., 4 figs,

  10. Design and development of a self-regenerative contained-liquid membrane process for combined SO{sub x} and NO{sub x} removal. Final report

    SciTech Connect

    Varanasi, S.; LeBlanc, S.E.

    1992-11-01

    The lack of an efficient, cost effective process for the removal of sulfur compounds from gas streams (either gasified coal or flue gases resulting from coal combustion) is a major obstacle to the economic utilization of high sulfur Ohio coal. The most economically favorable processes for the desulfurization of flue gases are the regenerable processes as opposed to the `throwaway` processes. In addition, recovery of sulfur from these gases in the form of elemental sulfur or H{sub 2}SO{sub 4} does seem to be an essential step in the economic utilization of high sulfur coal. n light of these observations, a recently proposed FGD process which regenerates the scrubbing liquor ``in-situ`` as well as recovering a concentrated S0{sub 2} stream for use in sulfuric acid production, is quite promising. Conventional processes, presently in operation, employ large packed tower scrubbers for S0{sub 2} absorption which results in very high capital expenditures and operating costs. Recent developments in membrane technology can now provide us with an alternative to these large packed towers for stack gas cleanup. In this research we have investigated the use of novel membrane contactors for replacing more conventional packed absorbers. Contained-liquid membranes, exploiting carrier mediated transpose, enable the scrubbing liquid to be regenerated ``in-site,`` in a single process unit. Microporous single-ply polymeric membranes have recently been used in gas-liquid and liquid-liquid contactors. These membranes are fashioned into a tubular shape (i.e. long, thin fibers) for use in mass transfer contactors.

  11. CRADA Final Report For CRADA NO. CR-12-006 [Operation and Testing of an SO{sub 2}-depolarized Electrolyzer (SDE) for the Purpose of Hydrogen and Sulfuric Acid Production

    SciTech Connect

    Summers, W. A.; Colon-Mercado, H. R.; Steimke, J. L.; Zahn, Steffen

    2014-02-24

    Over the past several years, Savannah River National Laboratory (SRNL) has led a team of collaborators under the Department of Energy’s (DOE) nuclear hydrogen production program to develop the Hybrid Sulfur (HyS) Process. HyS is a 2-step water-splitting process consisting of high temperature decomposition of sulfuric acid to generate SO{sub 2}, followed by the electrolysis of aqueous SO{sub 2} to generate hydrogen and sulfuric acid. The latter is fed back into the high temperature reactor. SRNL designed and built an SO{sub 2}-depolarized electrolyzer (SDE) and a test facility. Over 40 SDE’s were tested using different catalysts, membranes and other components. SRNL demonstrated that an SDE could be operated continuously for approximately 200 hours under certain conditions without buildup of sulfur at the SDE’s cathode, thus solving a key technical problem with SDE technology. Air Products and Chemicals, Inc. (APCI) is a major supplier of hydrogen production systems, and they have proprietary technology that could benefit from the SDE developed by SRNS, or some improved version thereof. However, to demonstrate that SRNL’s SDE is a truly viable approach to the electrolyzer design, continuous operation for far greater periods of time than 200 hours must be demonstrated, and the electrolyzer must be scaled up to greater hydrogen production capacities. SRNL and Air Products entered into a Cooperative Research and Development Agreement with the objective of demonstrating the effectiveness of the SDE for hydrogen and sulfuric acid production and to demonstrate long-term continuous operation so as to dramatically increase the confidence in the SDE design for commercial operation. SRNL prepared a detailed technical report documenting previous SDE development, including the current SDE design and operating conditions that led to the 200-hour sulfurfree testing. SRNL refurbished its single cell SDE test facility and qualified the equipment for continuous operation. A

  12. Cross-flow, filter-sorbent catalyst for particulate, SO{sub 2} and NO{sub x} control. First quarterly technical progress report, 1990

    SciTech Connect

    Not Available

    1990-03-01

    This synopsis describes a new concept for integrated pollutant control: a cross-flow filter comprised of layered, gas permeable membranes that act as a particulate filter, an SO{sub 2} sorbent, and a NO{sub x} reduction catalyst.

  13. Study of the reactivity of sodium compounds and Ca(OH){sub 2} towards SO{sub 2} and NO{sub x}

    SciTech Connect

    Mocke, K.; Stejskalova, K.; Bach, P.

    1995-06-01

    The J.Heyrovsky Institute of Physical Chemistry (IPC) has conducted a detailed basic research under contract to Solvay Company (Belgium) to examine the reactivity of solid substances towards acid gases (SO{sub 2},NO{sub x}) with the aim to find the best conditions for their efficient removal. The reactivity of different sodium compounds (sodium bicarbonate, active soda, sodium carbonate monohydrate, dense soda ash) and Ca(OH){sub 2} was examined in the reaction with sulphur dioxide in a broad range of experimental variables (temperature, gas composition). The reactivity of selected samples was investigated also in the reactions with gaseous mixtures containing SO{sub 2} and NO{sub x} in the dependence on temperature, SO{sub 2}/NO{sub x}, and NO/NO{sub 2} ratios and the hydrodynamic regime of the fixed bed flow reactor. Further, ESCA and SEM methods were used for the identification of solid reaction products and their evolution as a function of reaction parameters. It is shown that in the case of NaHCO{sub 3} precursor it is possible to achieve in average at least a 90 % SO{sub 2} and simultaneously an almost 50 % NO{sub x} removal. The results obtained are very promising with respect to the NaHCO{sub 3} utilization especially for the purification of waste gases from incinerators and power plants.

  14. Effects of exposure to NO{sub 2} or SO{sub 2} on bronchopulmonary reaction induced by Candida albicans in guinea pigs

    SciTech Connect

    Kitabatake, Masayoshi; Yamamoto, Hidetaka; Yuan, Piao Feng

    1995-09-01

    The effects of NO{sub 2} or SO{sub 2} on the bronchopulmonary reactions induced by Candida albicans in guinea pigs were evaluated. Thirty-six guinea pigs (3 groups of 12 animals each) were sensitized with intraperitoneal injection of 10 mg of C. albicans, given twice. Two groups of animals were exposed to about 5 ppm of NO{sub 2} or SO{sub 2} for 4 h/d, 5 d/wk; this exposure was conducted a total of 30 times during the study. The third group served as the control and was not exposed to these pollutants. Two weeks after the second sensitization, all the animals were subjected to inhalation exposure to C. albicans. For 42 h after the antigen challenge, the respiratory rates and expiration/inspiration ratios of the animals were automatically monitored. The number of animals showing tachypnea was significantly higher in the NO{sub 2} exposure group than in the control from 15 h after antigen challenge. In the SO{sub 2} exposure group, the number of animals showing prolonged expiration or prolonged inspiration, or both, was significantly higher than that in the control group, and the symptoms were observed from approximately 15 h after antigen challenge. These findings showed that delayed-type dyspneic symptoms in guinea pigs were increased by exposure to NO{sub 2} or SO{sub 2}, although the symptoms and degree of dyspnea were different for the two gases. 29 refs., 2 figs., 2 tabs.

  15. Simultaneous SO{sub 2}/NO/particulate removal from coal combustion gas by solid-state electrochemical technology. Final report

    SciTech Connect

    Cornell, L.P.; Cook, W.J.; Keyvani, M.; Neyman, M.; Helfritch, D.J.

    1991-01-21

    A solid-state electrochemical process now in an early stage of development converts NO{sub x}and SO{sub x} to nitrogen, oxygen, and sulfur. Process objectives are to remove 90+% of SO{sub x} and NO{sub x} and 99% of particulates from Ohio coal combustion flue gases. The electrochemical reactor cell uses ionically conductive ceramics as electrolyte, and electronically conductive materials (including some ceramics) as electrodes; there are no moving parts, no consumable reagents, no by-product sludges, and no process fluids except the flue gas. Downstream of the electro-chemical cell, particulates are removed with a filter or electrostatic precipitator and elemental sulfur is condensed. This work developed and tested electrocatalysts for their ability to selectively reduce SO{sub 2} and NO{sub x} in the presence of oxygen gas in concentrations typical of coal combustion flue gases. Several solid electrolytes and various electrode materials were also tested for use in the electrochemical cell. Gold was chosen as the electrode in the tests because it is porous, resistant to chemical attack, and conductive. Electrocatalyst coatings containing a single transition metal were applied to one inch diameter yttria stabilized ceria disks and tested for NO and SO{sub 2} reduction.

  16. Pilot-scale testing of a new sorbent for combined SO{sub 2}/NO{sub x} removal. Final report

    SciTech Connect

    Nelson, S. Jr.

    1994-06-01

    A new regenerable sorbent concept for SO{sub 2} and NOx removal was pilot-tested at Ohio Edison`s Edgewater generating station at a 1.5 to 2-MW(e) level. A radial panel-bed filter of a new dry, granular sorbent was exposed to flue gas and regenerated in an experimental proof-of-concept program. The project was successful in demonstrating the new sorbent`s ability to achieve 90% SO{sub 2} removal, 30% NOx removal, and over 80% removal of residual particulates with realistic approach temperatures and low pressure drops. Based on the results of this project, the retrofit cost of this technology is expected to be on the order of $400 per ton of SO{sub 2} and $900 per ton of NOx removed. This assumes that gas distribution is even and methane regeneration is used for a 30% average utilization. For a 2.5%-sulfur Ohio coal, this translates to a cost of approximately $17 per ton of coal. Two by-product streams were generated in the process that was tested: a solid, spent-sorbent stream and a highly-concentrated SO{sub 2} or elemental-sulfur stream. While not within the scope of the project, it was found possible to process these streams into useful products. The spent sorbent materials were shown to be excellent substrates for soil amendments; the elemental sulfur produced is innocuous and eminently marketable.

  17. Cross-flow, filter-sorbent-catalyst for particulate, SO{sub 2} and NO{sub x} control. Final report

    SciTech Connect

    Benedek, K.; Flytzani-Stephanopoulos, M.

    1994-05-01

    This report describes work performed on a new concept for integrated pollutant control: An active filter comprised of layered, gas permeable membranes that act as a particle filter, an SO{sub 2} sorbent, and a NO{sub x}, reduction catalyst. The focus of the research program documented in this final report is the development of the sorbent/catalyst materials that are the basis of such an emission control system. The device investigated in this program will simultaneously remove particulates, SO{sub 2} and NO{sub x}, from combustion exhaust gases. Sulfur dioxide capture and nitrogen oxide reduction are achieved with a reg le, mixed-metal oxide sorbent-catalyst. The device is a filter with layered walls: A small-pore layer is a barrier to particles, and a macroporus active layer is a SO{sub 2} sorbent and a catalyst for the selective catalytic reduction of NO{sub x}. The small-pore layer could be an inert ceramic that provides structural strength to the unit and protects the active (sorbent-catalyst) material from abrasion or contamination from fly ash particles. We have found that 95--100% removal efficiency of SO{sub 2} and 60--90% removal of NO{sub x}, is achievable with the use of mixed-metal oxide sorbent-catalysts in the device. The ceramic filters are barriers to particles and typically have removal efficiencies of 99.9%.

  18. Phase transformation of Ca{sub 4}[Al{sub 6}O{sub 12}]SO{sub 4} and its disordered crystal structure at 1073 K

    SciTech Connect

    Kurokawa, Daisuke; Takeda, Seiya; Colas, Maggy; Asaka, Toru; Thomas, Philippe; Fukuda, Koichiro

    2014-07-01

    The phase transformation of Ca{sub 4}[Al{sub 6}O{sub 12}]SO{sub 4} and the crystal structure of its high-temperature phase were investigated by differential thermal analysis, temperature-dependent Raman spectroscopy and high-temperature X-ray powder diffraction (CuKα{sub 1}). We determined the starting temperature of the orthorhombic-to-cubic transformation during heating (=711 K) and that of the reverse transformation during cooling (=742 K). The thermal hysteresis was negative (=−31 K), suggesting the thermoelasticity of the transformation. The space group of the high temperature phase is I4{sup ¯}3m with the unit-cell dimensions of a=0.92426(2) nm and V=0.78955(2) nm{sup 3} (Z=2) at 1073 K. The initial structural model was derived by the direct methods and further refined by the Rietveld method. The final structural model showed the orientational disordering of SO{sub 4} tetrahedra. The maximum-entropy method-based pattern fitting method was used to confirm the validity of the split-atom model, in which conventional structure bias caused by assuming intensity partitioning was minimized. At around the transformation temperature during heating, the vibrational spectra, corresponding to the Raman-active SO{sub 4} internal stretching mode, showed the continuous and gradual change in the slope of full width at half maximum versus temperature curve. This strongly suggests that the orthorhombic-to-cubic phase transformation would be principally accompanied by the statistical disordering in orientation of the SO{sub 4} tetrahedra, without distinct dynamical reorientation. - Graphical abstract: (Left) Three-dimensional electron-density distributions of the SO{sub 4} tetrahedron with the split-atom model, and (right) a bird's eye view of electron densities on the plane parallel to (111). - Highlights: • Crystal structure of Ca{sub 4}[Al{sub 6}O{sub 12}]SO{sub 4} at 1073 K is determined by powder XRD. • The atom arrangements are represented by the split-atom model

  19. Kinetics of the reaction of iron blast furnace slag/hydrated lime sorbents with SO{sub 2} at low temperatures: effects of the presence of CO{sub 2}, O{sub 2}, and NOx

    SciTech Connect

    Liu, C.F.; Shih, S.M.

    2009-09-15

    The effects of the presence of CO{sub 2}, O{sub 2}, and NOx in the flue gas on the kinetics of the sulfation of blast furnace slag/hydrated lime sorbents at low temperatures were studied using a differential fixed-bed reactor. When O{sub 2} and NOx were not present simultaneously, the reaction kinetics was about the same as that under the gas mixtures containing SO{sub 2}, H{sub 2}O, and N{sub 2} only, being affected mainly by the relative humidity. The sulfation of sorbents can be described by the surface coverage model and the model equations derived for the latter case. When both O{sub 2} and NOx, were present, the sulfation of sorbents was greatly enhanced, forming a great amount of sulfate in addition to sulfite. The surface coverage model is still valid in this case, but the model equations obtained show a more marked effect of relative humidity and negligible effects of SO{sub 2} concentration and temperature on the reaction. The effect of sorbent composition on the reaction kinetics was entirely represented by the effects of the initial specific surface area (S{sub g0}) and the Ca molar content (M{sup -1}) of sorbent. The initial conversion rate of sorbent increased linearly with increasing S{sub g0}, and the ultimate conversion increased linearly with increasing S{sub g0}M{sup -1}. The model equations obtained in this work are applicable to describe the kinetics of the sulfation of the sorbents in the low-temperature dry and semidry fine gas desulfurization processes either with an upstream NOx, removal unit or without.111

  20. Effects of H{sub 2}O, SO{sub 2}, and NO on homogeneous Hg oxidation by Cl{sub 2}

    SciTech Connect

    Hans Agarwal; Harvey G. Stenger; Song Wu; Zhen Fan

    2006-05-15

    Several researchers have determined that water (H{sub 2}O) and sulfur dioxide (SO{sub 2}) in a flue gas stream have an impact on the amount of elemental mercury (Hg{sup 0}) that is homogeneously oxidized by a chlorine-containing species. Generally, it is concluded that H{sub 2}O inhibits Hg oxidation by chlorine (Cl{sub 2}). However, doubt remains as to whether SO{sub 2} promotes or inhibits Hg oxidation. Further, most published results seem to indicate that nitric oxide (NO) does not have a significant impact on Hg oxidation. This paper will present data taken in a laboratory-scale apparatus designed to test these observations. In this work, Cl{sub 2} is intentionally added to a synthetic flue gas stream containing known amounts of elemental mercury. This gas blend is similar to a flue gas obtained by burning Powder River Basin coal in a pulverized coal fired power plant and is subject to a time-temperature profile similar to a power plant. The results obtained show that H{sub 2}O, SO{sub 2}, and NO all have an inhibitory effect on the homogeneous oxidation of Hg by Cl{sub 2}. Further, the presence of H{sub 2}O increases the inhibitory effect of SO{sub 2} and NO. Two new reactions are proposed to explain these results, in which SO{sub 2} and NO react with Cl{sub 2}. The consequences of these reactions are a reduction in the oxidative interactions that take place between Hg and Cl{sub 2}, thus decreasing the amount of Hg oxidation that occurs. 10 refs., 6 figs., 5 tabs.

  1. The Effects of Lithium Triflate (LiCF{sub 3}SO{sub 3}) on the PMMA-based Solid Polymer Electrolytes

    SciTech Connect

    Chew, K. W.; Chen, S. S.; Pang, W. L.; Tan, C. G.; Osman, Z.

    2010-03-11

    The effects of Lithium triflate salt (LiCF{sub 3}SO{sub 3}), on the poly (methyl methacrylate)(PMMA)-based solid polymer electrolytes plasticized with propylene carbonate (PC) solvated in Tetrahydrofuran (THF) have been studied through a.c impedance spectroscopy and infrared spectroscopy. Lithium triflate was incorporated into the predetermined PMMA/PC system that has the highest value of ionic conductivity. In current investigations, four combination systems: Pure PMMA, (PMMA+PC) systems, (PMMA+LiCF{sub 3}SO{sub 3}) and (PMMA+PC+LiCF{sub 3}SO{sub 3}) systems were prepared using the solution cast method. Solutions were stirred for numerous hours to obtain a homogenous solution before it is poured into the petri dishes under ambient temperature to form the solid electrolyte thin film. The films were then removed from petri discs and transferred into the dessicator for further drying prior to the different tests. From the characterization done through the a.c impedance spectroscopy, the highest room temperature ionic conductivity in the pure PMMA sample, (PMMA+PC) system and (PMMA+LiCF{sub 3}SO{sub 3}) system is 2.83x10{sup -12} Scm{sup -1}, 4.39x10{sup -11} Scm{sup -1} and 3.93x10{sup -6} Scm{sup -1} respectively. The conductivity for (PMMA+PC+LiCF{sub 3}SO{sub 3}) system was obtained with the 30 wt% of lithium triflate, which is 2.48x10{sup -5} Scm{sup -1}. Infrared spectroscopy shows that complexation occurred between the polymer and the plasticizer, and the polymer and plasticizer and salt. The interactions have been studied in the C=O band, C-O-C band and the O-CH{sub 3} band.

  2. Evaluation of the Community Multiscale Air Quality (CMAQ) modeling system against size-resolved measurements of inorganic particle composition across sites in North America

    EPA Science Inventory

    This work evaluates particle size-composition distributions simulated by the Community Multiscale Air Quality (CMAQ) model using Micro-Orifice Uniform Deposit Impactor (MOUDI) measurements at 18 sites across North America. Size-resolved measurements of particulate SO>4<...

  3. Modeling of SO/sub 2/ oxidation in smog. Final report

    SciTech Connect

    Miller, D.F.

    1981-06-01

    Smog chamber experiments were conducted to investigate the (1) kinetics of free radical reactions of SO2 in smog and (2) SO2 transformation to sulfate for atmospheric simulations. Rate constants were derived for the following reactions: SO2+HO+M yields sulfate (60), SO2+HO2 yields sulfate (61), SO2+CH3O2 yields sulfate (64); k(60) = 1600 k(61 less than 0.2, k(64) less than 0.8 ppm min. Oxidation of SO2 by HO led exclusively to particulate sulfate. Even under favorable NOx conditions, particulate nitrate was not a product. Hydrocarbon mixtures typical of urban environments promoted SO2 oxidation faster than hydrocarbons selected to represent rural conditions. Maximum rates of SO2 oxidation occurred during periods of peak NO2 formation. SO2 oxidation rates for aged smog were 25-35% of the maximum values. Model calculations indicated that reaction 60 dominates sulfate production from SO2 in polluted air. Models that adequately estimate (HO) in smog should suffice to approximate the conversion rates. The model used in this study indicated that SO2 oxidation depends strongly on solar radiation intensity and pollutant conditions. For clear-sky and a variety of HC-NOx conditions, maximum SO2 conversion rates ranged from 3.7-7.4%/hr. Models used to simulate reactions in power plant plumes showed that SO2 oxidation is strongly dependent on plume dispersion rates coupled to the same parameters governing SO2 oxidation in ambient air. Generally the rates of SO2 oxidation in plumes are bound by the ambient rates, although exceptions will occur for certain HC-NOx conditions.

  4. Air Research

    EPA Pesticide Factsheets

    EPA's air research provides the critical science to develop and implement outdoor air regulations under the Clean Air Act and puts new tools and information in the hands of air quality managers and regulators to protect the air we breathe.

  5. Assessing the air pollution carrying capacity of the northern Puget Sound region: an application of TAPAS

    SciTech Connect

    Wood, M.C.; Childs J.E.; Marlatt, W.E.

    1980-09-01

    The technique discussed, the Topographic Air Pollution Analysis System (TAPAS), was developed to provide valid information on the dispersion capability of the lower atmosphere in areas characterized by complex terrain features. A study was undertaken to assess the air quality (SO/sub 2/) impacts associated with energy development in the region and to determine the constraints on energy development due to regulated limitations on the amount of air quality degradation allowable in the area. The emission constraint analysis for the northern Puget Sound region indicated that total SO/sub 2/ emissions in the core area (on an annual basis) are less than half of the amount that could be tolerated in the entire core region while maintaining ambient concentrations within state and federal annual average limitations. However, comparison of source characteristics with source location and grid cell emission restrictions indicated that localized areas adjacent to the major point sources are already far in excess of the SO/sub 2/ carrying capacity. This conclusion is supported by air quality monitoring data that indicate state standard violations at several receptor locations within the study area. The annual maps of wind patterns and PI-Matrix values show areas of both good and poor dispersion characteristics under the most prevalent flow conditions.

  6. Superheater/intermediate temperature air heater tube corrosion tests in the MHD coal fired flow facility (Montana Rosebud POC tests)

    SciTech Connect

    White, M.

    1996-01-01

    Nineteen alloys have been exposed for approximately 1000 test hours as candidate superheater and intermediate temperature air heater tubes in a U.S. DOE facility dedicated to demonstrating Proof of Concept for the bottoming or heat and seed recovery portion of coal fired magnetohydrodynamic (MHD) electrical power generating plants. Corrosion data have been obtained from a test series utilizing a western United States sub-bituminous coal, Montana Rosebud. The test alloys included a broad range of compositions ranging from carbon steel to austenitic stainless steels to high chromium nickel-base alloys. The tubes, coated with K{sub 2}SO-containing deposits, developed principally, oxide scales by an oxidation/sulfidation mechanism. In addition to being generally porous, these scales were frequently spalled and/or non-compact due to a dispersed form of outward growth by oxide precipitation in the adjacent deposit. Austenitic alloys generally had internal penetration as trans Tranular and/or intergranular oxides and sulfides. While only two of the alloys had damage visible without magnification as a result of the relatively short exposure, there was some concern about Iona-term corrosion performance owing to the relatively poor quality scales formed. Comparison of data from these tests to those from a prior series of tests with Illinois No. 6, a high sulfur bituminous coal, showed less corrosion in the present test series with the lower sulfur coal. Although K{sub 2}SO{sub 4}was the principal corrosive agent as the supplier of sulfur, which acted to degrade alloy surface scales, tying up sulfur as K{sub 2}SO{sub 4} prevented the occurrence of complex alkali iron trisulfates responsible for severe or catastrophic corrosion in conventional power plants with certain coals and metal temperatures.

  7. Evaluation of official air sampling methodologies in Ukraine

    SciTech Connect

    Nakonechniy, J.J.; Wadden, R.A.; Scheff, P.A.; Suero, M.

    1997-12-31

    In conjunction with an environmental epidemiology study of the health of Ukrainian children, a significant amount of air pollution measurement data was gathered from government agencies. The areas of interest were the industrial city of Dneprodzherzhinsk; and the Dniprovsky region of Kyiv. The data were for 1993 and, for some of the monitoring stations, 1994. The pollutants reported included dust (approximately equivalent to TSP, total suspended particulate matter), SO{sub 2}, CO, NO{sub 2}, NO, H{sub 2}S, phenol, HCl, NH{sub 3}, formaldehyde, BaP, and lead. The ultimate goal was to evaluate whether existing historical data are appropriate for developing measures of human exposure. In order to evaluate the data it was necessary to understand the sampling and analytical methodologies which were used. Small sample volumes coupled with dated analytical procedures resulted in very poor precision and detection limits for most of the measured pollutants. The measurement of particulate matter is a good example of the limits imposed by the sampling methodology. The short sample time (20 min), small sample volume (150 lpm), and limited analytical balances (0.5 mg resolution) result in a minimum lower limit of detection of 0.25 mg/m{sup 3}. For example at Kyiv Station 3 in 1993, only one of 545 measurements exceeded 0.2 mg/m{sup 3}. This minimum detectable quantity is over three times the former US annual TSP standard. In addition, even when operated on a 24-hour basis in the US, it has been shown that the sampling method only collected approximately 34% of that collected by a co-located hi-vol sampler. Consequently, official air pollution data for suspended dust are likely to severely under-represent actual ambient concentrations. Data for other pollutants are presented and sampling and analytical methods are similarly compared with Western methods in common use.

  8. Regeneration process for spent SO/sub 2/-NO/sub x/ sorbents

    SciTech Connect

    Nelson, B.W.; Nelson, S.G.

    1989-05-09

    A regeneration process is described for MgO-vermiculite and MgO-perlite sorbents employed to remove nitrogen and sulfur oxides from a flue gas comprising the following steps: (a) Heating the spent sorbents in air to a temperature in the range of 100/sup 0/ to 350/sup 0/C to drive off substantially all free and chemically attached water; (b) Further heating the spent sorbents in an atmosphere containing a reducing gas selected from the group consisting of carbon monoxide, methane and hydrogen to a temperature in the range of 350/sup 0/ to 450/sup 0/C to drive off sorbed nitrogen oxides; (c) Further heating the spent sorbents in the same atmosphere containing a reducing gas to a temperature in the range of 450/sup 0/ to 700/sup 0/C to drive off approximately 90 percent of the sorbed sulfur in the form of sulfur oxides and elemental sulfur and to destroy substantially all nitrogen oxides present in the exit gases; (d) Cooling the sorbents to a temperature below 200/sup 0/C for reuse.

  9. 14 CFR 136.5 - Additional requirements for Hawaii.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... (CONTINUED) AIR CARRIERS AND OPERATORS FOR COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS COMMERCIAL AIR TOURS AND NATIONAL PARKS AIR TOUR MANAGEMENT National Air Tour Safety Standards § 136.5 Additional requirements for Hawaii. No person may conduct a commercial air tour in the State of Hawaii unless they...

  10. Environmental performance of air staged combustor with flue gas recirculation to burn coal/biomass

    SciTech Connect

    Anuar, S.H.; Keener, H.M.

    1995-12-31

    The environmental and thermal performance of a 1.07 m diameter, 440 kW atmospheric fluidized bed combustor operated at 700{degrees}C-920{degrees}C and burning coal was studied. Flue gas recirculation was incorporated to enhance the thermal performance and air staging was used to control emissions of SO{sub 2}, CO, NO{sub x} and N{sub 2}O. Studies focused on the effect of excess air, firing rate, and use of sorbent on system performance. The recirculation-staging mode with limestone had the highest thermal efficiency (0.67) using the firing equation. Emission data showed that flue gas recirculation (ratio of 0.7) significantly reduced NO{sub x} emissions; and that use of limestone sorbent at a Ca/S ratio of 3 reduced SO{sub 2} emissions by 64% to approximately 0.310 g/MJ.

  11. Measuring the benefits from air pollution abatement on human health and welfare: a case study of Jacksonville, Florida

    SciTech Connect

    Erfani-Ezati, G.

    1984-01-01

    The purpose of this study was to test benefit measures of air pollution to human health and welfare. Two market approaches, labor market (wage rate) and housing market (property value), were employed to estimate benefits from improvements in air quality. Indices of air pollution used in this study were sulfur dioxide (SO/sub 2/) and total suspended particulate matter (TSP). Using the labor market approach as a measure of benefits from improved air quality, a Mortality Effect Model (MEM) was developed. Then, the model was utilized to quantify the estimates of the pollution mortality relationship for the city of Jacksonville. The resulting pollution related mortality function was then monetized by applying estimates of individual's willingness to pay for mortality reductions. The MEM was estimated using multiple regression analysis. TSP showed no statistically significant association with mortality rates. The significance of the estimated coefficient for the pollution variable SO/sub 2/ supported the contention that some form of air pollution bears a positive and significant relationship to mortality rates. By utilizing a willingness to pay estimate for mortality reductions, it was concluded that individuals in Jacksonville would be willing to pay a minimum of $10 million annually, in order to maintain SO/sub 2/ concentrations at a level of 1% below the average for 1972.

  12. Multi-heat addition turbine engine

    NASA Technical Reports Server (NTRS)

    Franciscus, Leo C. (Inventor); Brabbs, Theodore A. (Inventor)

    1993-01-01

    A multi-heat addition turbine engine (MHATE) incorporates a plurality of heat addition devices to transfer energy to air and a plurality of turbines to extract energy from the air while converting it to work. The MHATE provides dry power and lower fuel consumption or lower combustor exit temperatures.

  13. Commercial demonstration of the NOXSO SO{sub 2}/NO{sub x} removal flue gas cleanup system

    SciTech Connect

    Renk, J.B. III

    1995-06-01

    This environmental assessment (EA) was prepared to evaluate the potential impacts of a proposed demonstration project to be cost-shared by DOE and NOXSO Corporation under the terms of Clean Coal Technology (CCT) Demonstration Program. The project would demonstrate the NOXSO flue gas treatment technology, which is designed to reduce sulfur dioxide (SO{sub 2}) and nitrogen oxides (NO{sub x}) emissions from existing coal-fired electric generating units. Its objective is to introduce advanced, efficient, reliable, and environmentally improved coal utilization technologies to the U.S. energy marketplace, in order to reduce or eliminate economic and environmental barriers to the continued use of coal as an energy source. This EA represents the third level of DOE`s NEPA strategy: the preparation and public distribution of NEPA documents for each project selected for financial assistance under the PON. It contains a site-specific environmental impact analysis of the proposed federal action, and will result in either a Finding of No Significant Impact, or a determination that significant impacts may occur, in which case an Environmental Impact Statement must be prepared. The sources of information for this EA include the technical proposal for the project submitted by NOXSO in response to the CCT Round III PON; discussions with NOXSO and their consultants; discussions with federal, state and local agencies; the April 1995 NOXSO Environmental Information Volume provided to DOE for the project; and visits to the proposed project sites.

  14. Anthropogenic SO{sub 2}/NO{sub x} committee summary of current status--annual inventory

    SciTech Connect

    Benkovitz, C.M.

    1992-06-01

    At the First GEIA Workshop on Global Emissions Inventories, held in Baltimore, MD on December 1--2, 1991, data on anthropogenic emissions of sulfur and nitrogen developed by Dignon (1992) were selected to form the basis for the GEIA SO{sub 2} and NO{sub x} annual inventories. The Dignon data include emissions from fuel combustion only and currently extend to 1980. The methodology used was detailed in Dignon and Hameed (1985) and consists of statistical regression models based on available emissions data from the U.S and some other member countries of the Organization of Economic Cooperation and Development (OECD), which includes Australia, Canada, Japan and western European countries. Control regulations are incorporated via the use of different statistical parameter The grid definition from these inventories was also adopted for the GEIA grid: origin at 180{degree}W, 90{degree}S, 1{degree} {times} 1{degree} resolution (i.e., 360 cells in the longitude direction, 180 cells in the latitude direction). To upgrade the basic GEIA inventories, data for the different geographic regions being solicited from researchers located within these areas. This paper contains the upgrades which have been accomplished to date.

  15. Simultaneous SO{sub 2}/NO{sub x} removal testing and toxics characterization. Milestone report, phase 1

    SciTech Connect

    Whitcomb, J.; Tseng, Shiaw; Lani, B.W.

    1996-09-01

    This report describes the work completed in the first phase of the Simultaneous SO{sub 2}/NO{sub x} Removal Testing and Toxics Characterization test program. Tasks covered in this report as specified in the Statement of Work included: Task 1.2.0 Equipment Modification and Reagents Procurement; Task 1.3.0 Testing at the 5 kW Scale; Task 1.3.1 Temperature Enhanced Fe(III)EDTA Reduction; Task 1.3.2 Electrolytic Cell Fe(III) EDTA Reduction; Task 1.3.3 Chemical Regeneration Agents Testing; Task 1.3.4 Combination of Strategies; Task 1.4.0 Data Analysis and Phase I Report. Proposed in Task 1.3.4 are combinations of regeneration methods (based on data generated in Tasks 1.3.1 to 1.3.3) that gave the best results at the lowest possible cost. The Test Plan approval (Task 1.1.0) was previously submitted under separate cover.

  16. /Air Atmospheres

    NASA Astrophysics Data System (ADS)

    Emami, Samar; Sohn, Hong Yong; Kim, Hang Goo

    2014-08-01

    Molten magnesium oxidizes rapidly when exposed to air causing melt loss and handling difficulties. The use of certain additive gases such as SF6, SO2, and CO2 to form a protective MgO layer over a magnesium melt has been proposed. The oxidation behavior of molten magnesium in air containing various concentrations of SF6 was investigated. Measurements of the kinetics of the oxide layer growth at various SF6 concentrations in air and temperatures were made. Experiments were performed using a thermogravimetric analysis unit in the temperature range of 943 K to 1043 K (670 °C to 770 °C). Results showed that a thin, coherent, and protective MgF2 layer was formed under SF6/Air mixtures, with a thickness ranging from 300 nm to 3 μm depending on SF6 concentration, temperature, and exposure time. Rate parameters were calculated and a model for the process was developed. The morphology and composition of the surface films were studied using scanning electron microscope and energy-dispersive spectroscope.

  17. Air Pollution

    MedlinePlus

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, ... Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's ...

  18. Conductivity enhancement in PVA−PEO−EC−LiCF−{sub 3}SO{sub 3} blends upon swift heavy O{sup 7+} ion irradiation

    SciTech Connect

    Joge, Prajakta Kanchan, D. K. Sharma, Poonam Jayswal, Manish; Awasthi, D. K.

    2014-04-24

    In the present study, the PVA−PEO−EC−LiCF−{sub 3}SO{sub 3} blend system was prepared using solution cast technique. The system was prepared by taking 5 different concentrations LiCF{sub 3}SO{sub 3} in the range of 3wt% to 11 wt%, at a fixed proportion of the rest of the constituents. These blend films had been exposed to O{sup 7+} radiations of 80 MeV at a current of 1pnA at a fluence of 1×10{sup 12} ions/cm{sup 2}. The conductivity variation of the specimens is investigated using impedance spectroscopy wherein; the conductivity enhances drastically upon irradiation at all the concentrations of salt. The thermal characteristics of the blend films are being studied using Differential Scanning Calorimetry.

  19. Dry desulfurization of simulated flue gas in a fluidized-bed reactor for a broad range of SO{sub 2} concentration and temperature: A comparison of models

    SciTech Connect

    Suyadal, Y.; Oguz, H.

    1999-08-01

    In this work, dry desulfurization of simulated flue gas was investigated in a batchwise operated laboratory-scale stainless steel fluidized-bed reactor (46 x 500 mm{sup 2}) by using calcium-containing local Turkish limestone (Karaagach/MUS) which was calcined at 900 C with 5% H{sub 2}O vapor. The sulfation reaction was carried out in a broad range of temperature (200 {le} T({degree}C) {le} 900) and SO{sub 2} feedstock concentration (1000 {le} C(ppm SO{sub 2}) {le} 6000). The experimental sulfation conversion-time data were tested according to unreacted shrinking core model (SCM), changing the grain size model (GM) and random pore model (RPM). It was found that the random pore model with control of product layer (CaSO{sub 3}/CaSO{sub 4}) diffusion described the experimental data best.

  20. Effect of water on sulfur dioxide (SO{sub 2}) and nitrogen oxides (NO{sub x}) removal from flue gas in a direct current corona discharge reactor

    SciTech Connect

    Yang, Jiaxiang; Chi, Xiaochun; Dong, Limin

    2007-05-15

    A direct current (dc) corona discharge reactor composed of needle-plate electrodes in a glass container filled with flue gas was designed. To clarify the influence of water on discharge characteristics, water was introduced in the plasma reactor as electrode where plate electrode is immersed, under the application of dc voltage. Experiment results show that (1) corona wind forming between high-voltage needle electrode and water by corona discharge enhances the cleaning efficiency of flue gas due to the existence of water and the cleaning efficiency will increase with the increase of applied dc voltage within definite range and (2) both removal efficiencies of NO{sub x} and SO{sub 2} increased in the presence of water, which reach up to 98% for SO{sub 2}, and about 85% for NO{sub x} under suitable conditions. These results play an important role in flue gas cleanup research.

  1. Automatic electrochemical ambient air monitor for chloride and chlorine

    DOEpatents

    Mueller, Theodore R.

    1976-07-13

    An electrochemical monitoring system has been provided for determining chloride and chlorine in air at levels of from about 10-1000 parts per billion. The chloride is determined by oxidation to chlorine followed by reduction to chloride in a closed system. Chlorine is determined by direct reduction at a platinum electrode in 6 M H.sub.2 SO.sub.4 electrolyte. A fully automated system is utilized to (1) acquire and store a value corresponding to electrolyte-containing impurities, (2) subtract this value from that obtained in the presence of air, (3) generate coulometrically a standard sample of chlorine mixed with air sample, and determine it as chlorine and/or chloride, and (4) calculate, display, and store for permanent record the ratio of the signal obtained from the air sample and that obtained with the standard.

  2. Response of sulfate concentration and isotope composition in Icelandic rivers to the decline in global atmospheric SO{sub 2} emissions into the North Atlantic region

    SciTech Connect

    Sigurdur Reynir Gislason; Peter Torssander

    2006-02-01

    This study presents the changes in dissolved sulfate concentration and isotope composition of Icelandic river waters between the peak of SO{sub 2} emissions in the United States and Europe and the present. Chloride concentration in Icelandic rivers has not changed much since 1972. The overall average change from 1972-1973 to 1996-2004 was -3%, indicating insignificant sea-salt contribution changes. More than 99% of the river-dissolved sulfur was in the form of sulfate. There are three main sources for dissolved sulfate in the rivers: rocks, sea-salts, and anthropogenic. Total dissolved sulfate, {sub td}SO{sub 4}{sup 2-}, and non-sea-salt sulfate, {sub nss}SO{sub 4}{sup 2-}, decreased in all of the rivers from the early 1970s to 1996-2004. The percentage decrease varies from 13% to 65%. The decrease is smallest in rivers were there is considerable rock-derived dissolved SO{sub 4}{sup 2-}. The overall average decrease was 39% for {sub td}SO{sub 4}{sup 2-} and 46% for {sub nss}SO{sub 4}{sup 2-}. The anthropogenic sulfate fraction has declined making most of the river waters {delta}{sup 34}S values of sulfate higher through time. The overall decline in river sulfate and increase in {delta}{sup 34}S, while SO{sub 2} emissions from Iceland has been increasing, demonstrates the response of river chemistry in the remote North Atlantic to the decline in man-made emissions of SO{sub 2} in North America and Europe. 43 refs., 8 figs., 1 tab.

  3. Investigation of combined SO{sub 2}/NO{sub x} removal by ceria sorbents. Quarterly technical progress report, October--December, 1994

    SciTech Connect

    Akyurtlu, A.; Akyurtlu, J.F.

    1995-01-01

    Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. Recent studies at PETC considered cerium oxide as an alternate sorbent to CuO. The present study aims to determine the effects of ammonia on the sulfation of the sorbent and to obtain a rate expression for the regeneration of alumina-supported CeO{sub 2} sorbents. The sulfation experiments indicated that 100% conversion of ceria could be attained. Activation energy for the sulfation reaction was found to be 19 kJ/mol. The rate of sulfation reaction is first order with respect to SO{sub 2} and solid reactant concentrations. For regeneration with hydrogen, the activation energy and the reaction order with respect to hydrogen was found to be 114 kJ/mol and 0.56, respectively. The ceria sorbent preserved its activity and structural stability after 6 cycles. The information obtained from these studies will be used to develop models for reactor-regenerator configurations. Subsequently, the SO{sub 2}/NO{sub x} removal facility will be integrated into the power production process using a commercial process simulation software. In this quarter of the project, the main focus was on the performance of the experimental program for the regeneration of the ceria sorbent by hydrogen and evaluation of experimental results.

  4. Development and testing of a PEM SO>2-depolarized electrolyzer and an operating method that prevents sulfur accumulation

    SciTech Connect

    Steimke, John L.; Steeper, Timothy J.; Colon-Mercado, Hector R.; Gorensek, Maximilian B.

    2015-09-02

    The hybrid sulfur (HyS) cycle is being developed as a technology to generate hydrogen by splitting water, using heat and electrical power from a nuclear or solar power plant. A key component is the SO>2-depolarized electrolysis (SDE) cell, which reacts SO>2 and water to form hydrogen and sulfuric acid. SDE could also be used in once-through operation to consume SO>2 and generate hydrogen and sulfuric acid for sale. A proton exchange membrane (PEM) SDE cell based on a PEM fuel cell design was fabricated and tested. Measured cell potential as a function of anolyte pressure and flow rate, sulfuric acid concentration, and cell temperature are presented for this cell. Sulfur accumulation was observed inside the cell, which could have been a serious impediment to further development. A method to prevent sulfur formation was subsequently developed. As a result, this was made possible by a testing facility that allowed unattended operation for extended periods.

  5. Advanced byproduct recovery: Direct catalytic reduction of SO{sub 2} to elemental sulfur. First quarterly technical progress report, [October--December 1995

    SciTech Connect

    Benedek, K.; Flytzani-Stephanopoulos, M.

    1996-02-01

    The team of Arthur D. Little, Tufts University and Engelhard Corporation will be conducting Phase I of a four and a half year, two-phase effort to develop and scale-up an advanced byproduct recovery technology that is a direct, single-stage, catalytic process for converting sulfur dioxide to elemental sulfur. this catalytic process reduces SO{sub 2} over a fluorite-type oxide (such as ceria or zirconia). The catalytic activity can be significantly promoted by active transition metals, such as copper. More than 95% elemental sulfur yield, corresponding to almost complete sulfur dioxide conversion, was obtained over a Cu-Ce-O oxide catalyst as part of an ongoing DOE-sponsored University Coal Research Program. This type of mixed metal oxide catalyst has stable activity, high selectivity for sulfur production, and is resistant to water and carbon dioxide poisoning. Tests with CO and CH{sub 4} reducing gases indicates that the catalyst has the potential for flexibility with regard to the composition of the reducing gas, making it attractive for utility use. the performance of the catalyst is consistently good over a range of SO{sub 2} inlet concentration (0.1 to 10%) indicating its flexibility in treating SO{sub 2} tail gases as well as high concentration streams.

  6. Implications of a stochastic approach to air-quality regulations

    SciTech Connect

    Witten, A.J.; Kornegay, F.C.; Hunsaker, D.B. Jr.; Long, E.C. Jr.; Sharp, R.D.; Walsh, P.J.; Zeighami, E.A.; Gordon, J.S.; Lin, W.L.

    1982-09-01

    This study explores the viability of a stochastic approach to air quality regulations. The stochastic approach considered here is one which incorporates the variability which exists in sulfur dioxide (SO/sub 2/) emissions from coal-fired power plants. Emission variability arises from a combination of many factors including variability in the composition of as-received coal such as sulfur content, moisture content, ash content, and heating value, as well as variability which is introduced in power plant operations. The stochastic approach as conceived in this study addresses variability by taking the SO/sub 2/ emission rate to be a random variable with specified statistics. Given the statistical description of the emission rate and known meteorological conditions, it is possible to predict the probability of a facility exceeding a specified emission limit or violating an established air quality standard. This study also investigates the implications of accounting for emissions variability by allowing compliance to be interpreted as an allowable probability of occurrence of given events. For example, compliance with an emission limit could be defined as the probability of exceeding a specified emission value, such as 1.2 lbs SO/sub 2//MMBtu, being less than 1%. In contrast, compliance is currently taken to mean that this limit shall never be exceeded, i.e., no exceedance probability is allowed. The focus of this study is on the economic benefits offered to facilities through the greater flexibility of the stochastic approach as compared with possible changes in air quality and health effects which could result.

  7. Novel technologies for SO{sub x}/NO{sub x} removal from flue gas. [Quarterly] technical report, September 1--November 30, 1994

    SciTech Connect

    Kung, H.; Kung, M.; Spivey, J.J.; Jang, B.W.

    1994-12-31

    The goal of this project is to develop a cost-effective low temperature deNO{sub x}, catalyst to be used in the Research Triangle Institute (RTI)-Waterloo SO{sub x}/NO{sub x} process for boiler retrofit applications. The performance goal of the catalyst is to convert over 80% of the NO in the flue gas at a temperature as low as 150{degrees}C in the presence of 4 % O{sub 2} and 10 % water. In this quarter a two prong approach was used: Northwestern University concentrated their effort to better understand the reduction of NO{sub x} with alcohol over CU-ZrO{sub 2} catalyst while RTI studied the oxidation of NO to NO,. The chief problem encountered in low temperature reduction of NO was catalyst deactivation, which occurred with all alcohols tested (ethanol, 1-propanol, 2-propanol and 2-butanol). This was probably due to coke formation, as regeneration of the catalyst can be achieved by heating in 4 % oxygen. Catalysts with higher Cu loadings deactivated slower. Use of NO{sub 2} instead of NO, in the hope to reduce catalyst coking, improved N{sub 2} yield temporarily but could not stop deactivation. NO oxidation to NO{sub 2} was studied over different catalysts to support the research to improve the stability of catalytic activity. In the presence of SO{sub 2} and H{sub 2}O at 150{degrees}C, the highest NO oxidation activity was observed over a 10 % CoO/Al{sub 2}O3 catalyst. The activity of the catalyst at first increased slowly, reaching a maximum at around 6 hours on stream, and then slowly decreased. The maximum activity as well as the activity profile with time on stream were affected by the presence of SO{sub 2}. With 0.2 % SO{sub 2}, the activity for NO oxidation to NO{sub 2} reached the maximum with 60 % conversion of NO at 3 hours on stream compared with 42 % at 6 hours when 0.1 % SO{sub 2} was used. The concentrations of O{sub 2}and H{sub 2}O also affected the NO oxidation activity.

  8. Contact air abrasion.

    PubMed

    Porth, R

    1999-05-01

    The advantages of contact air abrasion techniques are readily apparent. The first, of course, is the greatly increased ease of use. Working with contact also tends to speed the learning curve by giving the process a more natural dental feel. In addition, as one becomes familiar with working with a dust stream, the potential for misdirecting the air flow is decreased. The future use of air abrasion for deep decay removal will make this the treatment of choice for the next millennium.

  9. Storage corrosion of materials and equipment: Temperature-humidity and aerochemical regimes indoors and in the open air

    SciTech Connect

    Strekalov, P.V.

    1994-07-01

    The following storage factors are considered: (1) the temperature-humidity complex (THC) in the open air at representative sites with cold, moderate, and subtropical humid climate; (2) the temperature and humidity differences between the open air and an atmospheric of semiclosed spaces; (3) the THC inside storage-spaces in a humid tropical climate; (4) the concentration of SO{sub 2} and Cl{sup -} in the open air and in different storage-spaces; (5) the categories of corrosivity of the atmosphere and methods for its evaluation indoors and outdoors.

  10. 14 CFR 93.129 - Additional operations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Additional operations. 93.129 Section 93.129 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES High Density Traffic Airports §...

  11. Monitoring of mutagens and carcinogens in community air. Final report 1981-83

    SciTech Connect

    Flessel, P.; Guirguis, G.; Cheng, J.; Chang, K.; Hahn, E.

    1984-05-01

    This study measured the mutagenic activity of ambient aerosol extracts collected in Contra Costa County, Ca., identified and quantitated a number of organic compounds which contribute to the mutagenicity and determined some of the major contributing sources. Air sampling was carried out at four locations during 36-hour pollution episodes in August and October 1981 and in January 1982. Organic extracts of particulate matter were analyzed for mutagenic activity in the Ames Salmonella test and for polycyclic aromatic hydrocarbons (PAH) by HPLC with ultraviolet and fluorescence detection. Pb, Ni, Fe, NO/sub 3/(-1), SO/sub 4/(-2), O/sub 3/, CO, NO, NO/sub 2/, and SO/sub 2/ were also measured.

  12. Cooling of Gas Turbines I - Effects of Addition of Fins to Blade Tips and Rotor, Admission of Cooling Air Through Part of Nozzles, and Change in Thermal Conductivity of Turbine Components

    NASA Technical Reports Server (NTRS)

    Brown, Byron

    1947-01-01

    An analysis was developed for calculating the radial temperature distribution in a gas turbine with only the temperatures of the gas and the cooling air and the surface heat-transfer coefficient known. This analysis was applied to determine the temperatures of a complete wheel of a conventional single-stage impulse exhaust-gas turbine. The temperatures were first calculated for the case of the turbine operating at design conditions of speed, gas flow, etc. and with only the customary cooling arising from exposure of the outer blade flange and one face of the rotor to the air. Calculations were next made for the case of fins applied to the outer blade flange and the rotor. Finally the effects of using part of the nozzles (from 0 to 40 percent) for supplying cooling air and the effects of varying the metal thermal conductivity from 12 to 260 Btu per hour per foot per degree Farenheit on the wheel temperatures were determined. The gas temperatures at the nozzle box used in the calculations ranged from 1600F to 2000F. The results showed that if more than a few hundred degrees of cooling of turbine blades are required other means than indirect cooling with fins on the rotor and outer blade flange would be necessary. The amount of cooling indicated for the type of finning used could produce some improvement in efficiency and a large increase in durability of the wheel. The results also showed that if a large difference is to exist between the effective temperature of the exhaust gas and that of the blade material, as must be the case with present turbine materials and the high exhaust-gas temperatures desired (2000F and above), two alternatives are suggested: (a) If metal with a thermal conductivity comparable with copper is used, then the blade temperature can be reduced by strong cooling at both the blade tip and root. The center of the blade will be less than 2000F hotter than the ends; (b) With low conductivity materials some method of direct cooling other than

  13. Observation of b2 symmetry vibrational levels of the SO>2C 1B2 state: Vibrational level staggering, Coriolis interactions, and rotation-vibration constants

    SciTech Connect

    Park, G. Barratt; Jiang, Jun; Saladrigas, Catherine A.; Field, Robert W.

    2016-04-14

    Here, the C 1B2 state of SO>2 has a double-minimum potential in the antisymmetric stretch coordinate, such that the minimum energy geometry has nonequivalent SO bond lengths. However, low-lying levels with odd quanta of antisymmetric stretch (b2 vibrational symmetry) have not previously been observed because transitions into these levels from the zero-point level of the X~ state are vibronically forbidden. We use IR-UV double resonance to observe the b2 vibrational levels of the C state below 1600 cm–1 of vibrational excitation. This enables a direct characterization of the vibrational level staggering that results from the double-minimum potential. In addition, it allows us to deperturb the strong c-axis Coriolis interactions between levels of a1 and b2 vibrational symmetry, and to determine accurately the vibrational dependence of the rotational constants in the distorted C electronic state.

  14. Tests of stability on waste produced in pilot plant testing using ferrous{center_dot}EDTA and magnesium-enhanced lime for combined SO{sub 2}/NO{sub x} removal

    SciTech Connect

    Mendelsohn, M.H.; Livengood, C.D.

    1994-03-01

    A pilot-plant-scale study of combined sulfur dioxide/nitrogen oxides (SO{sub 2}/NO{sub x}) removal has been performed by the Dravo Lime Company at the Cincinnati Gas and Electric Company`s Miami Fort Station in North Bend, Ohio. This study used Dravo`s patented Thiosorbic{reg_sign} lime process, utilizing a magnesium-enhanced lime, along with Argonne National Laboratory`s (ANL`s) patented ARGONOX metal-chelate additive, ferrous{center_dot}ethylenediaminetetraacetic acid (Fe{center_dot}EDTA). For approximately nine months, scrubbing tests were carried out, and waste samples were collected. Waste testing at ANL involved two types of long-term chemical stability experiments. In one experiment, the gas-phase composition above several different samples was studied by mass spectrometry over a period of about 22 months. Significant changes were noted for oxygen (O{sub 2}), carbon dioxide (CO{sub 2}), and hydrogen sulfide (H{sub 2}S) gases. The other experiment involved solid-phase leaching using the Toxicity Characteristic Leaching Procedure (TCLP). Samples were stored for up to 14 months before leaching. Then each leachate was tested for total Kjeldahl nitrogen and for some nitrogen-containing species. Total leachable nitrogen was found to stabilize after about the first seven months of storage.

  15. Experimental study of the SO{sub 2} removal efficiency and scale formation in limestone FGD process with lab and pilot test facility

    SciTech Connect

    Lee, S.Y.; Baek, J.J.; Kim, B.H.

    1997-12-31

    There are several tens of processes applied to Flue Gas Desulfurization (FGD) process in the world, which can be classified as wet, semi-dry and dry type. Among them, the wet type FGD is the most widely applied process for the large scale plant, such as power plant. The fundamental reasons of the preference for the wet type process are its high reliability and economic aspects. About 90% of the wet type process applied to actual plants is using the limestone -based gypsum process. Even though the limestone-based FGD process has simple construction and reliable SO{sub 2} removal efficiency, it has some problems in long-period continuous operation. Among these, the most serious one is the scaling. Scale is the solid mixture of reaction intermediate and by-product formed during various chemical reaction steps of FGD process. There are three types of scale in FGD absorber: calcium sulfite, gypsum, and CSS (Coprecipitated Calcium Sulfate and Sulfite). They have the tendency to precipitate on the absorber internals, such as packing, spray nozzles, mist eliminator, and surface of absorber itself, causing plugging, thus reducing the operation reliability. The major factor responsible for such problem is the lack of understanding for calcium sulfur salts chemistry, which occurred during the reaction steps of FGD process. In this study, the effect of operating conditions--gas velocity, gas temperature, SO{sub 2} concentration, L/G ratio, slurry concentration, etc.--on the SO{sub 2} removal efficiency and scale formation will be investigated. The scale formation mechanism will be studied to verify in a lab-scale test and the control method of scale for reliable operation will be established by the application of the lab-scale test result to pilot-scale facility test.

  16. Preconception and early pregnancy air pollution exposures and risk of gestational diabetes mellitus

    SciTech Connect

    Robledo, Candace A.; Mendola, Pauline; Yeung, Edwina; Männistö, Tuija; Sundaram, Rajeshwari; Liu, Danping; Ying, Qi; Sherman, Seth; Grantz, Katherine L.

    2015-02-15

    Background: Air pollution has been linked to gestational diabetes mellitus (GDM) but no studies have evaluated impact of preconception and early pregnancy air pollution exposures on GDM risk. Methods: Electronic medical records provided data on 219,952 singleton deliveries to mothers with (n=11,334) and without GDM (n=208,618). Average maternal exposures to particulate matter (PM) ≤ 2.5 μm (PM{sub 2.5}) and PM{sub 2.5} constituents, PM ≤ 10 μm (PM{sub 10}), nitrogen oxides (NO{sub x}), carbon monoxide, sulfur dioxide (SO{sub 2}) and ozone (O{sub 3}) were estimated for the 3-month preconception window, first trimester, and gestational weeks 1–24 based on modified Community Multiscale Air Quality models for delivery hospital referral regions. Binary regression models with robust standard errors estimated relative risks (RR) for GDM per interquartile range (IQR) increase in pollutant concentrations adjusted for study site, maternal age and race/ethnicity. Results: Preconception maternal exposure to NO{sub X} (RR=1.09, 95% CI: 1.04, 1.13) and SO{sub 2} (RR=1.05, 1.01, 1.09) were associated with increased risk of subsequent GDM and risk estimates remained elevated for first trimester exposure. Preconception O{sub 3} was associated with lower risk of subsequent GDM (RR=0.93, 0.90, 0.96) but risks increased later in pregnancy. Conclusion: Maternal exposures to NO{sub x} and SO{sub 2} preconception and during the first few weeks of pregnancy were associated with increased GDM risk. O{sub 3} appeared to increase GDM risk in association with mid-pregnancy exposure but not in earlier time windows. These common exposures merit further investigation. - Highlights: • Air pollution may be related to gestational diabetes (GDM). • No prior studies have examined preconception exposure. • Maternal exposure to NO{sub x} and SO{sub 2} before conception increased subsequent GDM risk. • NO{sub x} and SO{sub 2} exposure in the first seven weeks of pregnancy also increased

  17. Kemira selects outokumpu H/sub 2/SO/sub 4/ plant for Harjavalta, Finland with acid distributor system featuring LEWMET alloy flow components

    SciTech Connect

    Stuart, W.M.; Heinemann, H.C.; Pimia, E.

    1986-01-01

    With a population of 5 million people, Finland ranks as one of Europe's leading fertilizer producers. Thus, it is not surprising that per capita production of sulphuric acid, used in the manufacture of phosphate fertilizer, is among the highest in the world. Finland's leading fertilizer and sulphuric acid producer is Kemira Oy. When a new acid plant was under consideration for their complex at Harjavalta, the decision was made to use the best available technology. Replacing a 25-year old facility, the new plant was to operate on copper smelter SO/sub 2/ gas and have a capacity of 330,000 metric tons of sulphuric acid per year.

  18. Kentucky Department for Natural Resources and Environmental Protection permit application for air contaminant source: SRC-I demonstration plant, Newman, Kentucky. Supplement I. [Additional information on 38 items requested by KY/DNREP

    SciTech Connect

    Pearson, Jr., John F.

    1981-02-13

    In response to a letter from KY/DNREP, January 19, 1981, ICRC and DOE have prepared the enclosed supplement to the Kentucky Department for Natural Resources and Environmental Protection Permit Application for Air Contaminant Source for the SRC-I Demonstration Plant. Each of the 38 comments contained in the letter has been addressed in accordance with the discussions held in Frankfort on January 28, 1981, among representatives of KY/DNREP, EPA Region IV, US DOE, and ICRC. The questions raised involve requests for detailed information on the performance and reliability of proprietary equipment, back-up methods, monitoring plans for various pollutants, composition of wastes to flares, emissions estimates from particular operations, origin of baseline information, mathematical models, storage tanks, dusts, etc. (LTN)

  19. Corrosion behavior of carbon steel in the monoethanolamine-H{sub 2}O-CO{sub 2}-O{sub 2}-SO{sub 2} System: products, reaction pathways, and kinetics

    SciTech Connect

    Kladkaew, N.; Idem, R.; Tontiwachwuthikul, P.; Saiwan, C.

    2009-12-15

    This work investigates the effect of operating parameters on corrosion products, reaction pathways, and kinetics For the corrosion of carbon steel in the monoethanolamine-H{sub 2}O-CO{sub 2}-O{sub 2}-SO{sub 2} system. Corrosion experiments were conducted using a 273A potentiostat unit under conditions in which monoethanolamine (MEA), O{sub 2}, and SO{sub 2} concentrations and CO{sub 2} loading were in the range of 1-7 kmol/m{sup 3}, 0-100%, 0-204 ppm, and 0-0.5 mol CO{sub 2}/mol MEA, respectively, at corrosion temperatures of 303-353 K to mimic the absorption-regeneration sections. Analysis, performed for this system for the first time, shows that corrosion products generated from the effect of SO{sub 2} include FeSO{sub 4} and Fe{sub 2}O{sub 3} {center_dot} H{sub 2}O. Also, a higher concentration of SO{sub 2} in simulated flue gas stream induces a higher corrosion rate because of the increase in the hydrogen ion concentration generated by reactions of SO{sub 2} and H{sub 2}O as well as SO{sub 2}, O{sub 2}, and H{sub 2}O. A power-law model developed to correlate corrosion rate with the parameters in the MEA-H{sub 2}O-CO{sub 2}-O{sub 2}-SO{sub 2} system shows that corrosion rate of carbon steel increases with an increase in O{sub 2} and SO{sub 2} concentrations in simulated flue gas stream, as well as MEA concentration, CO{sub 2} loading, and operating temperature. It was observed that CO{sub 2} loading had the highest impact on the corrosion rate, while SO{sub 2} and O{sub 2} show only slight effects on the corrosion rate.

  20. Air pollution effects on the structure of Citrus aurantium leaves

    SciTech Connect

    Psaras, G.K.; Christodoulakis, N.S.

    1987-09-01

    Individual air pollutants cause acute and chronic plant injury, act on stomata and affect carbon dioxide exchange as well as plant growth and development. Inhibition of photosynthesis by several air pollutants has been reported repeatedly. Besides, structural modifications of cell organelles have been reported after fumigation by SO/sub 2/. Although chlorosis and subsequent necrosis are common phenomena caused by artificial treatment with pollutants, fine structural leaf characteristics of plants exposed to long-term air pollution in natural conditions are little explored. Light microscope examination of air pollution affected leaves of plants common in natural ecosystems of Athens' metropolitan area revealed chlorosis phenomena. Electron microscope examination of the leaves of a common subshrub of greek phryganic formations grown in a heavily air polluted natural ecosystem of Athens metropolitan area revealed pronounced ultrastructural anomalies of chloroplasts, mitochondria and microbodies of the mesophyll cells. This organelle destruction of the photosynthesizing tissue as well as the minimization of the ecosystem primary productivity are attributed to the compound action of several toxic air pollutants of the photochemical smog of Athens. This work describes the long-term air pollution effects on the structural features of the leaves of Citrus aurantium, a decorative species planted throughout the heavily air polluted city of Athens.

  1. Kinetics of Mn{sub 2}O{sub 3} digestion in H{sub 2}SO{sub 4} solutions

    SciTech Connect

    Walanda, Daud K.; Lawrance, Geoffrey A.; Donne, Scott W.

    2009-06-15

    The kinetics of Mn{sub 2}O{sub 3} digestion in various H{sub 2}SO{sub 4} solutions (0.5-2.0 M) and at various temperatures (ambient to 80 deg. C) to form solid gamma-MnO{sub 2} and soluble Mn(II) have been examined using X-ray diffraction. Using a modified first-order Avrami expression to describe digestion kinetics, rate constants in the range 0.02-0.98 h{sup -1} were found for Mn{sub 2}O{sub 3} disappearance, and 0.03-0.42 h{sup -1} for gamma-MnO{sub 2} formation, with higher H{sub 2}SO{sub 4} concentrations and temperatures leading to faster conversion rates. Also, for a particular set of experimental conditions, the rate of gamma-MnO{sub 2} formation was always slower than Mn{sub 2}O{sub 3} disappearance. This was interpreted in terms of the solubility and stability of the soluble Mn(III) intermediated formed during the digestion. Activation energies for Mn{sub 2}O{sub 3} dissolution and gamma-MnO{sub 2} formation were also determined. - Graphical Abstract: Manganese dioxide phase diagram resulting from the acid digestion of Mn{sub 2}O{sub 3}.

  2. Simultaneous SO{sub 2}/NO{sub x} abatement using zeolite-supported copper. Quarterly progress report, January 1, 1995--March 31, 1995

    SciTech Connect

    Mitchell, M.B.; White, M.G.

    1995-12-01

    We have significantly improved on our earlier results with a copper-impregnated alumina, obtaining reproducible results for the impregnation procedure and linear behavior with solution concentration of the precursor. The copper acetylacetonate precursor is adsorbed molecularly onto the alumina surface, with no noticeable decomposition. The adsorbed complex appears to form layers on the alumina surface, similar to results found using the same complex with a silica substrate. The materials start out as light blue powders, and after oxidation are light green. Using infrared spectroscopy, we have examined the in situ adsorption and oxidation of SO{sub 2} on the oxidized sorbent, which is dispersed copper oxide supported on aluminum oxide, and have observed that the initial species formed correspond to aluminum sulfate and aluminum sulfate. The sulfate is formed at temperatures much lower than similar experiments studying SO{sub 2} adsorption on alumina and sodium-doped alumina. As a result of oxidation, the adsorbed sulfur species, which begin as aluminum sulfate and sulfate, are converted to copper sulfate.

  3. Interaction of low-expansion NZP ceramics with Na{sub 2}SO{sub 4} at 1000{degrees}C

    SciTech Connect

    Lee, W.Y.; Cooley, K.M.; Stinton, D.P.; Joslin, D.L.

    1996-08-01

    The interaction between several low-expansion NZP materials and Na{sub 2}SO{sub 4} at 1000{degrees}C in pure O{sub 2} was studied. Ba{sub 1.25}Zr{sub 4}P{sub 5.5}Si{sub 0.5}O{sub 24} experienced extensive cracking and delamination upon reaction with Na{sub 2}SO{sub 4}. On the other hand, Ca{sub 0.5}Sr{sub 0.5}Zr{sub 4}P{sub 6}O{sub 24} remained intact in terms of visual appearance, and had no significant weight loss or gain. However, the ion exchange between Na{sup +} ions and Ca{sup +2} ions was observed to be sufficiently rapid to allow the penetration of the Na{sup +} ions into the test specimens in 100h. The segregation of Ca to the specimen surface was observed due to the ion exchange. Ca{sub 0.6}Mg{sub 0.4}Zr{sub 4}P{sub 6}O{sub 24} was also tested, but its stability could not properly be assessed because the as-received specimens contained a significant amount of MgZr{sub 4}P{sub 6}O{sub 24} as an impurity phase.

  4. Use of ferrous chelates of SH-containing amino acids and peptides for the removal of NO/sub x/ and SO/sub 2/ from flue gas

    SciTech Connect

    Chang, S.G.; Littlejohn, D.; Liu, D.K.

    1988-11-01

    The use of ferrous complexes of SH-containing amino acids and peptides for the removal of NO and SO/sub 2/ in wet flue gas clean-up systems is reported. The ferrous chelates investigated in the present study include those of cysteine, N-acetylcysteine, penicillamine, N-acetylpenicillamine, glutathine, and cysteinylglycine. Compared to conventional chelates such as EDTA, these thioamino acids/peptides not only can stabilize ferrous ion in alkaline solutions to promote the absorption of NO but are also capable of rapidly reducing any ferric ions formed during the scrubbing process back to ferrous ions so that continual absorption of NO can be achieved. In the case of ferrous cysteine and ferrous penicillamine, most of the absorbed NO is reduced to N/sub 2/. The disulfide form of several of the thioamino acids/peptides produced upon oxidation can be conveniently reduced by SO/sub 2/ and H/sub 2/S to regenerate the starting materials, thus making possible the recycling of the reagents.

  5. Plant growth and soil microorganisms responses to SO/sub 2/, NO/sub 2/, and ozone as affected by soils

    SciTech Connect

    Roberts, B.W.

    1987-01-01

    Glycine max (L.) Merr. cv. Nathan, Phaseolus vulgaris (L.) cv. Bush Blue Lake, and Lycopersicon esculentum (Mill.) cv. Tiny Tim grown in four soils were exposed to O/sub 3/. General responses were linear declines in dry weight with increasing levels of O/sub 3/. Soil and O/sub 3/ interactions occurred with P. vulgaris, but not with other species. In two related studies, L esculentum was exposed to SO/sub 2/ and NO/sub 2/ in various combinations. Nitrogen dioxide alone either increased or had no effect on plant dry weight. Sulfur dioxide alone inhibited growth at 0.2 uL L/sup -1/ and stimulated growth at 0.3 uL L/sup -1/. Sulfur dioxide and NO/sub 2/ in combination inhibited growth more than either pollutant alone. Rhizosphere microorganism populations in the same studies sometimes showed significant changes in response to pollutants, but were affected much more by soils in which the plants were grown than by either SO/sub 2/ or NO/sub 2/.

  6. Ionic interactions and transport properties in methyl terminated poly(propylene glycol)(4000) complexed with LiCF{sub 3}SO{sub 3}

    SciTech Connect

    Ferry, A.

    1997-01-09

    Alternating current (ac) impedance, restricted diffusion, and vibrational spectroscopic (Raman and IR) measurements have been conducted on complexes of methyl capped poly(propylene glycol) of molecular weight 4000 and LiCF{sub 3}SO{sub 3} salt. The relative concentrations of anions in different chemical environments have been calculated from an analysis of the symmetric anion SO{sub 3} stretch (Raman) over a wide concentration range. Comparisons are made to previous studies on hydroxyl capped PPG systems, and we find that polar polymer end groups play an important role in the solvation of the salt. The relative fraction of anions interacting directly with lithium cations is considerably higher over the entire concentration range in the present study, and we infer the existence of negatively charged ionic aggregates in the solutions. We also note that the fraction of spectroscopically `free` anions increases with increasing salt concentration in the ether oxygen to alkali metal cation ratio (O:M) range 502:1 to 12:1, contrary to a decrease reported for the analogue hydroxyl terminated electrolytes. The ionic conductivity has a more pronounced concentration dependency in the methyl capped system; notably, the molar conductivity ({Lambda}) increases dramatically with increasing salt concentration passing through a relatively sharp maximum at O:M = 20:1 at room temperature. 71 refs., 8 figs., 1 tab.

  7. Interaction of low-expansion NZP ceramics with Na{sub 2}SO{sub 4} at 1000{degrees}C

    SciTech Connect

    Lee, W.Y.; Stinton, D.P.; Joslin, D.L.

    1996-06-01

    The interaction between several low-expansion NZP materials and Na{sub 2}SO{sub 4} at 1000{degrees}C in pure O{sub 2} was studied. Ba{sub 1.25}Zr{sub 4}P{sub 5.5}Si{sub 0.5}O{sub 24} experienced extensive cracking and delamination upon reaction with Na{sub 2}SO{sub 4}. On the other hand, Ca{sub 0.5}Sr{sub 0.5}Zr{sub 4}P{sub 6}O{sub 24} remained intact in terms of visual appearance, and had no significant weight loss or gain. However, the ion exchange between Na{sup +} ions and Ca{sup +2} ions was observed to be sufficiently rapid to allow the penetration of the Na{sup +} ions into the test specimens in 100 h. The segregation of Ca to the specimen surface was observed due to the ion exchange. Ca{sub 0.6}Mg{sub 0.4}Zr{sub 4}P{sub 6}O{sub 24} was also tested, but its stability could not properly be assessed because the as-received specimens contained a significant amount of MgZr{sub 4}P{sub 6}O{sub 24} as an impurity phase.

  8. Effect of pollutant dose on the response of Mexican bean beetle (Coleoptea: Coccinellidae) to SO/sub 2/-induced changes in soybean

    SciTech Connect

    Hughes, P.R.; Chiment, J.J.; Dickie, A.I.

    1985-12-01

    Larvae of the Mexican bean beetle, Epilachna varivestis Mulsant, grew larger when fed on soybean foliage fumigated for 24 h with SO/sub 2/ at concentrations of 131 to 1834 ..mu..g m/sup -3/ than when fed on nonfumigated leaves. Relative weight gain was not linear against SO/sub 2/ concentration in the range sampled; it was greatest when leaves were fumigated with ca. 786 ..mu..g m/sup -3/ and less pronounced at either higher or lower concentrations. Smaller relative weight gains, also having a maximum at a concentration of approximately 786 ..mu..g m/sup -3/, were found when larvae were reared on foliage allowed 24 h in which to recover from fumigation. No effect on growth was observed when plants were fumigated with 65 ..mu..g m/sup -3/, indicating a threshold for effect between 65 and 131 ..mu..g m/sup -3/ under the conditions of these tests. Change in the plant induced by fumigation, as indicated by growth response of the insects, was rapid, occurring in less than 6 h when plants were fumigated at a concentration of 1310 ..mu..g m/sup -3/; recovery of the plant from an exposure was slow relative to response time.

  9. Metal-air battery assessment

    SciTech Connect

    Sen, R.K.; Van Voorhees, S.L.; Ferrel, T.

    1988-05-01

    The objective of this report is to evaluate the present technical status of the zinc-air, aluminum/air and iron/air batteries and assess their potential for use in an electric vehicle. In addition, this report will outline proposed research and development priorities for the successful development of metal-air batteries for electric vehicle application. 39 refs., 25 figs., 11 tabs.

  10. Iron-Air Rechargeable Battery

    NASA Technical Reports Server (NTRS)

    Narayan, Sri R. (Inventor); Prakash, G.K. Surya (Inventor); Kindler, Andrew (Inventor)

    2014-01-01

    Embodiments include an iron-air rechargeable battery having a composite electrode including an iron electrode and a hydrogen electrode integrated therewith. An air electrode is spaced from the iron electrode and an electrolyte is provided in contact with the air electrode and the iron electrodes. Various additives and catalysts are disclosed with respect to the iron electrode, air electrode, and electrolyte for increasing battery efficiency and cycle life.

  11. Applications Using AIRS Data

    NASA Astrophysics Data System (ADS)

    Ray, S. E.; Pagano, T. S.; Fetzer, E. J.; Lambrigtsen, B.; Olsen, E. T.; Teixeira, J.; Licata, S. J.; Hall, J. R.; Thompson, C. K.

    2015-12-01

    The Atmospheric Infrared Sounder (AIRS) on NASA's Aqua spacecraft has been returning daily global observations of Earth's atmospheric constituents and properties since 2002. With a 12-year data record and daily, global observations in near real-time, AIRS data can play a role in applications that fall under many of the NASA Applied Sciences focus areas. For vector-borne disease, research is underway using AIRS near surface retrievals to assess outbreak risk, mosquito incubation periods and epidemic potential for dengue fever, malaria, and West Nile virus. For drought applications, AIRS temperature and humidity data are being used in the development of new drought indicators and improvement in the understanding of drought development. For volcanic hazards, new algorithms using AIRS data are in development to improve the reporting of sulfur dioxide concentration, the burden and height of volcanic ash and dust, all of which pose a safety threat to aircraft. In addition, anomaly maps of many of AIRS standard products are being produced to help highlight "hot spots" and illustrate trends. To distribute it's applications imagery, AIRS is leveraging existing NASA data frameworks and organizations to facilitate archiving, distribution and participation in the BEDI. This poster will communicate the status of the applications effort for the AIRS Project and provide examples of new maps designed to best communicate the AIRS data.

  12. 75 FR 27313 - Proposed Additions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-14

    .../Location: Basewide Custodial, Naval Air Station, Joint Reserve Base, (Air Force Buildings Only), 301st CONF.... of the Air Force, FA6675 301 LRS LGC, Naval Air Station JRB, TX. Service Type/Location: Grounds Maintenance, Naval Air Station, Joint Reserve Base, (Air Force Property Only), 1710 Burke Street, Fort...

  13. Trends in visibility, PM{sub 2.5}, and deposition expected from the Acid Rain Provisions of the 1990 Clean Air Act Amendments

    SciTech Connect

    Shannon, J.D.; Hanson, D.A.

    1997-08-01

    The Acid Rain Provisions (Title IV) of the 1990 Clean Air Act Amendments (CAAA) are designed to reduce the deposition of SO{sub 2} and sulfate and, to a lesser extent, the deposition of NO{sub x} and nitrate through reduction of SO{sub 2} and NO{sub x} emissions. However, other important benefits are anticipated from the emission control strategies, including improvement of regional visibility and reductions in concentrations of fine particles (PM2.5). In this study, the authors coupled utility emissions forecasts with the Advanced Statistical Trajectory Regional Air Pollution (ASTRAP) model and the Visibility Assessment Scoping Model (VASM) to calculate and compare the relative improvements by 2010 in visual impairment, PM2.5 concentrations, and sulfate wet deposition at selected sites in the eastern United States.

  14. Relationship between high concentration of air pollutants and meteorological condition in Nagoya, a coastal city in central Japan

    SciTech Connect

    Mori, Hiroaki; Kitada, Toshihiro

    1996-12-31

    To obtain knowledge for urban and regional planning suitable for the prevention of air pollution, the relationship between the high concentration of air pollutants and the meteorological condition was statistically investigated, using hourly SO{sub 2} and NO{sub x} concentration data measured in Nagoya for one year from April 1985 through March 1986. First, the daily average and maximum concentration of SO{sub 2} and NO{sub x} were calculated. Secondly, the {open_quotes}polluted days{close_quotes} were selected for each of warm and cool periods: the polluted days stand for those in which the concentrations at more than 50% of the monitoring stations of all within the highest thirties. Thirdly, for those selected days the diurnal variations of SO{sub 2}, NO{sub x} and meteorological factors such as wind speed, wind direction and atmospheric stability, were analyzed. Results are as follows. In the warm period, there was a clear difference in meteorological condition between the high-SO{sub 2} and high-NO{sub x} days. The high-SO{sub 2} days appeared mainly in {open_quotes}land and sea breezes{close_quotes} situation (hereafter LSB), which occurs in fine weather with light synoptic pressure gradient. In the days, SO{sub 2} concentration at many observation points showed sharp and clear peak in a day. Namely, the SO{sub 2} concentration reaches its peak value when sea breeze front passes over the observation point, and then decreases rapidly. On the other hand, the high-NO{sub x} concentrations usually occurs in cloudy and rainy days with weak mean wind (hereafter BW, {open_quotes}bad weather{close_quotes}). In these days, NO{sub x} concentration gradually rises to its peak value in the morning, and remains high during daytime. In the cool period, both of the high SO{sub 2} and NO{sub x} concentrations appeared mainly with the BW situation, and sometimes with a fine weather under very weak synoptic-scale pressure gradient conditions.

  15. Mode of action of air pollutants in injuring horticultural plants

    SciTech Connect

    Tibbitts, T.W.; Kobriger, J.M.

    1983-10-01

    An attempt has been made to condense the great volume of literature for many different air pollutants and from many different plant systems. Only those responses that have been reported for several species are emphasized and the discussion is limited to responses obtained with intact plants. The general outline provides a focus; uptake becomes the crucial aspect of whether or not plants are injured by air pollutants. Pollutants must get into the plant to cause injury and the primary portal of entry is through the open stomata. Once into the plant, pollutants alter biochemical reactions, resulting in cell injury and causing economic losses for horticulturists. The authors have developed this outline for the pollutants sulfur dioxide (SO/sub 2/), hydrogen fluoride (HF), ozone (O/sub 3/), nitrogen dioxide (NO/sub 2/), and peroxyacetyl nitrate (PAN), which are the most common and and most damaging gaseous pollutants in the ambient environment.

  16. Air Pollution.

    ERIC Educational Resources Information Center

    Gilpin, Alan

    A summary of one of our most pressing environmental problems, air pollution, is offered in this book by the Director of Air Pollution Control for the Queensland (Australia) State Government. Discussion of the subject is not restricted to Queensland or Australian problems and policies, however, but includes analysis of air pollution the world over.…

  17. Air Pollution

    MedlinePlus

    ... of Climate Change on Children's Health: Session Two: Air Quality Impacts MODERATOR: Susan Anenberg, EPA Meredith McCormack, Johns ... University • Effects of Climate Change on Children’s Health: Air Quality Impacts Frederica Perera, Columbia University • Air quality Impacts ...

  18. Micronized coal-fired retrofit system for SO{sub x} reduction - Krakow Clean Fossil Fuels and Energy Efficiency Program.

    SciTech Connect

    1996-09-30

    the project proposes to install a new TCS micronized coal-fired heating plant for the Produkcja I Hodowla Roslin Ogrodniczych (PHRO) Greenhouse Complex, Krzeszowice, Poland (about 20 miles west of Krakow). PHRO currently utilizes 14 heavy oil-fired boilers to produce heat for its greenhouse facilities and also home heating to several adjacent apartment housing complexes. The boilers currently burn a high-sulfur content heavy crude oil, called Mazute. The micronized coal fired boiler would (1) provide a significant portion of the heat for PHRO and a portion of the adjacent apartment housing complexes, (2) dramatically reduce sulfur dioxide air pollution emission, while satisfying new Polish air regulations, and (3) provide attractive savings to PHRO, based on the quantity of displaced oil.

  19. THE EFFECT OF BROADBAND SOFT X-RAYS IN SO{sub 2}-CONTAINING ICES: IMPLICATIONS ON THE PHOTOCHEMISTRY OF ICES TOWARD YOUNG STELLAR OBJECTS

    SciTech Connect

    Pilling, S.; Bergantini, A.

    2015-10-01

    We investigate the effects produced mainly by broadband soft X-rays up to 2 keV (plus fast (∼keV) photoelectrons and low-energy (∼eV) induced secondary electrons) in the ice mixtures containing H{sub 2}O:CO{sub 2}:NH{sub 3}:SO{sub 2} (10:1:1:1) at two different temperatures (50 and 90 K). The experiments are an attempt to simulate the photochemical processes induced by energetic photons in SO{sub 2}-containing ices present in cold environments in the ices surrounding young stellar objects (YSO) and in molecular clouds in the vicinity of star-forming regions, which are largely illuminated by soft X-rays. The measurements were performed using a high-vacuum portable chamber from the Laboratório de Astroquímica e Astrobiologia (LASA/UNIVAP) coupled to the spherical grating monochromator beamline at the Brazilian Synchrotron Light Source (LNLS) in Campinas, Brazil. In situ analyses were performed by a Fourier transform infrared spectrometer. Sample processing revealed the formation of several organic molecules, including nitriles, acids, and other compounds such as H{sub 2}O{sub 2}, H{sub 3}O{sup +}, SO{sub 3}, CO, and OCN{sup −}. The dissociation cross section of parental species was on the order of (2–7) × 10{sup −18} cm{sup 2}. The ice temperature does not seem to affect the stability of SO{sub 2} in the presence of X-rays. Formation cross sections of new species  produced were also determined. Molecular half-lives at ices toward YSOs due to the presence of incoming soft X-rays were estimated. The low values obtained employing two different models of the radiation field of YSOs (TW Hydra and typical T-Tauri star) reinforce that soft X-rays are indeed a very efficient source of molecular dissociation in such environments.

  20. Testing and commercialization of byproduct dibasic acids as buffer additives for limestone flue gas desulfurization systems

    SciTech Connect

    Chang, J.C.S.; Mobley, J.D.

    1983-10-01

    Pilot plant (0.1 MW) tests and utility boiler full scale demonstration (194 MW) of byproduct organic dibasic acids (DBA) as buffer additives to limestone scrubbers have shown performance improvements equivalent to those achieved by the addition of pure adipic acid. Both SO/sub 2/ removal efficiency and limestone utilization increased, and no significant operating problems were observed with three of the four DBA tested. Chemical and biological evaluations of scrubber samples taken during the DBA testing indicated no detectable toxicity or mutagenicity, and no significant environmental impact is expected as a result of DBA addition. Economic estimates indicate that substitution of DBA for pure adipic acid as a buffer additive will result in additive cost savings of 30% or greater.

  1. Analysis of air pollution and greenhouse gases

    SciTech Connect

    Benkovitz, C.M.

    1992-03-01

    The current objective of the project Analysis of Air Pollution and Greenhouse Gases'' is to develop a study of emissions and emission sources that could easily be linked to models of economic activity. Initial studies were conducted to evaluate data currently available linking activity rates and emissions estimates. The emissions inventory developed for the National Acid Precipitation Assessment Program (NAPAP) presents one of the most comprehensive data sets, and was chosen for our initial studies, which are described in this report. Over 99% of the SO{sub 2} emissions, 98% of the NO{sub x} emission and 57% of the VOC emissions from area sources are related to fuel combustion. The majority of emission from these sources are generated by the transportation sector. Activity rates for area sources are not archived with the NAPAP inventory; alternative derivations of these data will be part of the future activities of this project. The availability and completeness of the fuel heat content data in the NAPAP inventory were also studied. Approximately 10% of the SO{sub 2} emissions, 13% of the NO{sub x} emissions and 46% of the VOC emissions are generated by sources with unavailable data for fuel heat content. Initial estimates of pollutant emission rate per unit fuel heat content. Initial estimates of pollutant emission rate per unit fuel heat content were generated. Future studies for this project include the derivation of activity rates for area sources, improved explanations for the default fuel parameters defined in the NAPAP inventory and the development of links to data bases of economic activity.

  2. Development of autoclavable addition type polyimides

    NASA Technical Reports Server (NTRS)

    Jones, R. J.; Vaughan, R. W.; Orell, M. K.; Sheppard, C. H.

    1974-01-01

    Two highly promising approaches to yield autoclavable addition-type polyimides were identified and evaluated in the program. Conditions were established for autoclave preparation of Hercules HMS graphite fiber reinforced composites in the temperature range of 473 K to 505 K under an applied pressure of 0.7 MN/m2 (100 psi) for time durations up to four hours. Upon oven postcure in air at 589 K, composite samples demonstrated high mechanical property retention at 561 K after isothermal aging in air for 1000 hours. Promise was shown for shorter term mechanical property retention at 589 K upon exposure in air at this temperature.

  3. An Electron Microscopy Investigation of the Transient Stage Oxidation Products in an Fe-22Cr Alloy with Ce and La Additions Exposed to Dry Air at 800 [degrees]C

    SciTech Connect

    Zhu, Jingxi; Fernandez Diaz, Laura M; Holcomb, Gordon R; Jablonski, Paul; Cowen, Christopher; Laughlin, David E; Alman, Dave; Seetharaman, Sridhar

    2011-01-01

    In this study, the effects of Ce (270 ppm) and La (120 ppm) mischmetal additions on the transient oxidation of an Fe-22Cr alloy were investigated. The oxidation process was imaged in situ using a confocal scanning laser microscope. The oxidation microstructures were studied by scanning electron microscopy, energy dispersive X-ray analysis, and transmission electron microscopy with the help of focused ion beam in situ lift-out specimen preparation. The Ce and La, referred to as reactive elements, were found in nonmetallic inclusion particles in the forms of oxides, sulfides, and phosphates. An affected zone formed around rare earth (RE)-containing inclusion particles at the alloy free surface during the transient oxidation. This zone consisted of an internal Cr-oxide formed beneath the particle as well as a thinner external oxide scale on the surface compared with the surroundings. The relation of this microstructure to oxidation kinetics is discussed. With time, the RE elements diffused into the scale from the RE particles on the alloy surface during the high-temperature exposure. A diffusion mechanism is presented to describe these observations.

  4. An Electron Microscopy Investigation of the Transient Stage Oxidation Products in an Fe-22Cr Alloy with Ce and La Additions Exposed to Dry Air at 1073 K (800 °C)

    SciTech Connect

    Jingxi Zhu; Laura Fernandez-Diaz; Gordon Holcomb; Paul Jablonski; Christopher Cowen; David Lauglin; and Sridhar Seetharaman

    2010-10-01

    In this study, the effects of Ce (270 ppm) and La (120 ppm) mischmetal additions on the transient oxidation of an Fe-22Cr alloy were investigated. The oxidation process was imaged in situ using a confocal scanning laser microscope. The oxidation microstructures were studied by scanning electron microscopy, energy dispersive X-ray analysis, and transmission electron microscopy with the help of focused ion beam in situ lift-out specimen preparation. The Ce and La, referred to as reactive elements, were found in nonmetallic inclusion particles in the forms of oxides, sulfides, and phosphates. An affected zone formed around rare earth (RE)-containing inclusion particles at the alloy free surface during the transient oxidation. This zone consisted of an internal Cr-oxide formed beneath the particle as well as a thinner external oxide scale on the surface compared with the surroundings. The relation of this microstructure to oxidation kinetics is discussed. With time, the RE elements diffused into the scale from the RE particles on the alloy surface during the high-temperature exposure. A diffusion mechanism is presented to describe these observations.

  5. Electrolysis products in a system formed by Na/sub 2/SO/sub 4/ solution with Al (OH)/sub 3/ hydrogel

    SciTech Connect

    Epifanov, Y.V.; Kul'skii, L.A.; Matskevich, E.S.

    1985-11-01

    This paper examines the dissolution of aluminum hydroxide gel on the electrolysis of aqueous electrolyte solutions and determine the compositions of the resulting compounds and the current yields. The authors used sodium sulfate to provide equivalent production of acid or alkali in the anode and cathode chambers. There is close correspondence between the anolyte and catholyte potentiometric and conductometric titration curves, which means that the methods can be used to analyze the electrolysis products in electrochemical coagulant regeneration. Data presented for determining the contents of the soluble aluminum compounds in the anolyte and catholyte in relation to the amount of electricity passed. It is shown that electrolysis in the system Na/sub 2/SO/sub 4/ solution + Al (OH)/sub 3/ hydrogel in a diaphragmed electrolyzer provides water-soluble aluminum compounds: aluminum sulfate as intermediate and basic salts in the anolyte and an alkaline solution of sodium aluminate in the catholyte.

  6. Investigation of the acidic properties of ZrO{sub 2} modified by SO{sub 4}{sup 2{minus}} anions

    SciTech Connect

    Kustov, L.M.; Kazansky, V.B.; Figueras, F.; Tichit, D.

    1994-11-01

    Zirconium dioxide modified by sulfate anions was investigated using diffuse reflectance IR spectroscopy. It was found that this modification enhanced the strength of both Bronsted acid sites (terminal or bridging ZrOH groups) and Lewis acid sites (low-coordinate Zr ions). However, Bronsted acid sites with enhanced strength appeared to be weaker than bridging OH groups in zeolites. Modification also created protons with a new environment. These protons were assumed to form multicenter bonds with oxygen atoms of SO{sub 4}{sup 2{minus}} anions or with neighboring basic oxygen and to possess acidic properties, comparable to those of protons in zeolites. Low-temperature ethylene and cyclopropane oligomerization and H-D exchange were shown to proceed on sulfated zirconia, presumably with participation of such sites. 25 refs., 11 figs., 1 tab.

  7. Nanoparticles of K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3}:Eu as effective detectors for swift heavy ions

    SciTech Connect

    Salah, Numan; Lochab, S. P.; Kanjilal, D.; Ranjan, Ranju; Habib, Sami S.; Rupasov, A. A.; Aleynikov, V. E.

    2007-09-15

    The modification of thermoluminescence (TL) and photoluminescence (PL) properties of K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3}:Eu nanoparticles by swift heavy ions (SHI), irradiation is studied. Pellets form of the nanomaterials were irradiated by 48 MeV Li{sup 3+}, 75 MeV C{sup 6+}, and 90 MeV O{sup 7+} ion beams. The fluence range is 1x10{sup 9}-1x10{sup 13} ions/cm{sup 2}. The modification in TL glow curves of the nanomaterials irradiated by Li{sup 3+}, C{sup 6+}, and O{sup 7+} ion beams are essentially similar to those induced by {gamma}-ray irradiation. These glow curves have single peaks at around 427 K with a small variation in their positions by around {+-}3 K. The TL intensity of the ion beams irradiated nanomaterials is found to decease, while going from low to high atomic number (Z) ions (i.e., Li{sup 3+}{yields}O{sup 7+}). The TL response curve of the pellets irradiated by Li{sup 3+} ions is linear in the whole range of studied fluences. The curves for C{sup 6+} and O{sup 7+} irradiated samples are linear at lower fluences (1x10{sup 9}-1x10{sup 12} ion/cm{sup 2}) and then saturate at higher fluence. These results for the nanomaterials are much better than that of the corresponding microcrystalline samples irradiated with a Li{sup 3+} ion. The curves were linear up to the fluence 1x10{sup 11} ion/cm{sup 2} and then become sublinear at higher fluences. The TL efficiency values of K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3}:Eu nanoparticles irradiated by 48 MeV Li{sup 3+}, 75 MeV C{sup 6+}, and 90 MeV O{sup 7+} ion beams have been measured relative to {gamma} rays of {sup 60}Co and are found to be 0.515, 0.069, and 0.019, respectively. This value for the Li{sup 3+} ion (0.515) is much higher than that of the corresponding microcrystalline material (0.0014). These superiorities for the nanomaterials make K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3}:Eu nanophosphor a suitable candidate for detecting the doses of swift heavy ions. PL studies on the ion beams irradiated and

  8. Production and use of activated char for combined SO{sub 2}/NO{sub x} removal. Technical report, March 1, 1994--May 31, 1994

    SciTech Connect

    Lizzio, A.A.; DeBarr, J.A.; Kruse, C.W.; Rostam-Abadi, M.; Donnals, G.L.; Rood, M.J.

    1994-09-01

    Carbon adsorbents have been shown to remove sulfur oxides from flue gas, and also serve as a catalyst for reduction of nitrogen oxides at temperatures between 80 and 150{degrees}C. The overall objective of this project is to determine whether Illinois coal is a suitable feedstock for the production of activated char which could be used as a catalyst for combined SO{sub 2}/NO{sub x} removal, and to evaluate the potential application of the products in flue gas cleanup. Key production variables will be identified to help design and engineer activated char with the proper pore structure and surface chemistry to enable the development of an effective SO{sub 2}/NO{sub x} removal catalyst. The ISGS agreed to provide 500 pounds of activated char to STEAG for tests in a demonstration unit to clean flue gas from a U.S. waste incinerator. The STEAG process requires an activated char with a N{sub 2} BET surface area < 300 m{sup 2}/g, i.e., lower than that of most commercially available activated carbons. An extensive series of tests was conducted to determine process conditions for making such an adsorbent from a Colchester No. 2 coal (Industry Mine coal). Using a 4 in. ID continuous rotary tube kiln (RTK) and a continuous feed charring oven, pound quantities of activated char were produced that matched well the properties of the adsorbent currently used by STEAG. A three step process, which included preoxidation, pyrolysis, and activation, was devised to produce a suitable char from this caking coal.

  9. Comparative study of the reactions of metal oxides and carbonates with H{sub 2}S and SO{sub 2}. Final technical report, September 1990--February 1994

    SciTech Connect

    Sotirchos, S.V.

    1994-03-01

    The primary objective of this project had been the investigation of the effects of pore structure on the capacity of porous metal oxides for removal of gaseous pollutants from flue gases of power plants (SO{sub 2}) and hot coal gas (primarily H{sub 2}S). Porous calcines obtained from natural precursors (limestones and dolomites) and sorbents based on zinc oxide were used as model systems in our experimental studies, which included reactivity evolution experiments and pore structure characterization using a variety of methods. The key idea behind this project was to appropriately exploit the differences of the sulfidation and sulfation reactions (for instance, different molar volumes of solid products) to elucidate the dependence of the sorptive capacity of a porous sorbent on its physical microstructure. In order to be able to proceed faster and more productively on the analysis of the above defined problem, it was decided to employ in our studies solids whose reaction with SO{sub 2} (limestone calcines) or H{sub 2}S (sorbents based on zinc oxide) had been investigated in detail in past studies by our research group. Reactivity vs time or conversion vs time studies were conducted using thermogravimetry and fixed-bed and fluidized-bed reactors. The pore structure of partially reacted samples collected at selected time instants or conversion levels was analyzed by gas adsorption and mercury porosimetry. For better characterization of the pore structure of the solid samples, we also carried out intraparticle diffusivity measurements by the peak-broadening (chromatographic) method, using a system developed for this purpose in our laboratory. In the context of this part of the project, we also conducted a detailed theoretical investigation of the measurement of effective diffusivities in porous solids using the diffusion-cell method.

  10. The impact of SO/sub 2/ on potatoes chronically stressed with ozone. Final report April 1978-August 1979

    SciTech Connect

    Foster, K.W.

    1980-11-01

    Potato crops in the San Joaquin Valley of California may be damaged by air pollution, specifically ozone and/or sulfur dioxide. Experiments at the University of California, Riverside, were conducted to examine the effects of four levels of ambient oxidant treatment in factorial combination with two levels of sulfur dioxide treatment on yield and quality of 'Centennial', a russet-skinned cultivar. Root and shoot dry weights and tuber yield were linearly reduced by oxidant treatments. Sulfur dioxide effects were less marked but of possible importance. No treatment effects on dry matter or sugar contents of tubers were observed.

  11. An investigation of infiltration and indoor air quality

    SciTech Connect

    Not Available

    1990-09-01

    A multitask study was performed in the State of New York to provide information for guiding home energy conservation programs while maintaining acceptable indoor air quality. During this study, the statistical distribution of radon concentrations inside 2400 homes was determined. The relationships among radon levels, house characteristics, and sources were also investigated. The direct impact that two specific air infiltration reduction measures -- caulking and weatherstripping of windows and doors, and installation of storm windows and storm doors -- have on house air leakage was investigated in 60 homes. The effect of house age on the impact of weatherization was also evaluated. Indoor and outdoor measurements of NO{sub 2}, CO, SO{sub 2}, and respirable suspended particulates (RSP) were made for 400 homes to determine the effect of combustion sources on indoor air quality and to characterize the statistical distribution of the concentrations. Finally, the combustion source data were combined with the information on air infiltration reduction measures to estimate the potential impact of these measures on indoor air quality. 87 tabs.

  12. synthesis and physicochemical properties of UO/sub 2/SO/sub 3/. 2CO(NH/sub 2/)/sub 2/. nH/sub 2/O (n = 0, or 1)

    SciTech Connect

    Serezhkina, L.B.; Blatov, V.A.; Serezhkin, V.N.

    1986-07-01

    Compound UO/sub 2/SO/sub 3/.2CO(NH/sub 2/)/sub 2/.H/sub 2/O was obtained by the reaction of uranyl sulfite with carbamide in an aqueous solution. X-Ray diffraction characteristics were determined, and the IR spectra, structure, and thermal stability of the compound synthesized are discussed.

  13. Volcanic gas emissions and their impact on ambient air character at Kilauea Volcano, Hawaii

    SciTech Connect

    Sutton, A.J.; Elias, T.; Navarrete, R.

    1994-12-31

    Gas emissions from Kilauea occur from the summit caldera, along the middle East Rift Zone (ERZ), and where lava enters the ocean. We estimate that the current ERZ eruption of Kilauea releases between 400 metric tonnes of SO{sub 2} per day, during eruptive pauses, to as much as 1850 metric tonnes per day during actively erupting periods, along with lesser amounts of other chemically and radiatively active species including H{sub 2}S, HCl and HF. In order to characterize gas emissions from Kilauea in a meaningful way for assessing environmental impact, we made a series of replicate grab-sample measurements of ambient air and precipitation at the summit of Kilauea, along its ERZ, and at coastal sites where lava enters the ocean. The grab-sampling data combined with SO{sub 2} emission rates, and continuous air quality and meteorological monitoring at the summit of Kilauea show that the effects of these emissions on ambient air character are a complex function of chemical reactivity, source geometry and effusivity, and local meteorology. Prevailing tradewinds typically carry the gases and aerosols released to the southwest, where they are further distributed by the regional wind regime. Episodes of kona, or low speed variable winds sometimes disrupt this pattern, however, and allow the gases and their oxidation products to collect at the summit and eastern side of the island. Summit solfatara areas of Kilauea are distinguished by moderate to high ambient SO{sub 2}, high H{sub 2}S at one location, and low H{sub 2}S at all others, and negligible HCl concentrations, as measured 1 m from degassing point-sources. Summit solfatara rain water has high sulfate and low chloride ion concentrations, and low pH.

  14. Air Policing

    DTIC Science & Technology

    2009-05-01

    Iraq. To provide a background for understanding why Britain commenced the policy of air policing, this paper begins with a review of contemporary...7 Omissi, Air Power, XV. 8 policing actions or the pushing home of advantages gained by the air.” Within the context of this paper , the...control operations, and therefore within the context of this paper , the term coercive airpower refers to the threat of harming a population or the threat

  15. Oblique view of east side mechanical additions and south side ...

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

    Oblique view of east side mechanical additions and south side of 1955 addition, facing northwest. - Albrook Air Force Station, Dispensary, East side of Canfield Avenue, Balboa, Former Panama Canal Zone, CZ

  16. Microbial reduction of SO{sub 2} and NO{sub x} as a means of by- product recovery/disposal from regenerable processes for the desulfurization of flue gas. Technical progress report, June 11, 1992--September 11, 1992

    SciTech Connect

    Sublette, K.L.

    1992-12-31

    Based on the work described simultaneous SO{sub 2}/No{sub x} removal from flue gas based on direct contact of the gas with SRB and T. denitrificans co-cultures or cultures-in-series has been eliminated as a viable process concept at this time. The technical reasons are as follows: (1) NO inhibition of SO{sub 2} reduction by D. desulfuricans - Although the NO concentrations used in the experiments described above are somewhat higher than that found in a typical flue gas, it is quite possible that at lower NO concentrations (or partial pressures) the inhibiting effects will simply take longer to become apparent. (2) Nitrate suppression of NO removal - As noted previously, the cultivation of T. denitrificans in a microbial flue gas treatment system (either one or two stages) would require sulfide-limiting conditions. Therefore, the electron acceptor must be in excess, requiring nitrate in the T. denitrificans process culture. As shown in experiments described above, nitrate significantly suppresses the removal of NO from a feed gas making simultaneous SO{sub 2}/NO{sub x} removal impractical by microbial means. (3) O{sub 2} inhibition of SO{sub 2} and NO reduction - It has been demonstrated that D. desulfuricans working cultures are tolerant of up to 1.7% O{sub 2} in the feed gas. However, further increases in the O{sub 2} partial pressure in the feed gas resulted in O{sub 2} inhibition of SO{sub 2} reduction. These inhibiting levels of O{sub 2} are comparable to those concentrations found in flue gases (3). Therefore, in any process in which raw flue gas contacts a D. desulfuricans culture marginal stability at best can be expected.

  17. Microbial reduction of SO[sub 2] and NO[sub x] as a means of by- product recovery/disposal from regenerable processes for the desulfurization of flue gas

    SciTech Connect

    Sublette, K.L.

    1992-01-01

    Based on the work described simultaneous SO[sub 2]/No[sub x] removal from flue gas based on direct contact of the gas with SRB and T. denitrificans co-cultures or cultures-in-series has been eliminated as a viable process concept at this time. The technical reasons are as follows: (1) NO inhibition of SO[sub 2] reduction by D. desulfuricans - Although the NO concentrations used in the experiments described above are somewhat higher than that found in a typical flue gas, it is quite possible that at lower NO concentrations (or partial pressures) the inhibiting effects will simply take longer to become apparent. (2) Nitrate suppression of NO removal - As noted previously, the cultivation of T. denitrificans in a microbial flue gas treatment system (either one or two stages) would require sulfide-limiting conditions. Therefore, the electron acceptor must be in excess, requiring nitrate in the T. denitrificans process culture. As shown in experiments described above, nitrate significantly suppresses the removal of NO from a feed gas making simultaneous SO[sub 2]/NO[sub x] removal impractical by microbial means. (3) O[sub 2] inhibition of SO[sub 2] and NO reduction - It has been demonstrated that D. desulfuricans working cultures are tolerant of up to 1.7% O[sub 2] in the feed gas. However, further increases in the O[sub 2] partial pressure in the feed gas resulted in O[sub 2] inhibition of SO[sub 2] reduction. These inhibiting levels of O[sub 2] are comparable to those concentrations found in flue gases (3). Therefore, in any process in which raw flue gas contacts a D. desulfuricans culture marginal stability at best can be expected.

  18. Air bag restraint device

    DOEpatents

    Marts, D.J.; Richardson, J.G.

    1995-10-17

    A rear-seat air bag restraint device is disclosed that prevents an individual, or individuals, from continuing violent actions while being transported in a patrol vehicle`s rear seat without requiring immediate physical contact by the law enforcement officer. The air bag is activated by a control switch in the front seat and inflates to independently restrict the amount of physical activity occurring in the rear seat of the vehicle while allowing the officer to safely stop the vehicle. The air bag can also provide the officer additional time to get backup personnel to aid him if the situation warrants it. The bag is inflated and maintains a constant pressure by an air pump. 8 figs.

  19. Air bag restraint device

    DOEpatents

    Marts, Donna J.; Richardson, John G.

    1995-01-01

    A rear-seat air bag restraint device is disclosed that prevents an individual, or individuals, from continuing violent actions while being transported in a patrol vehicle's rear seat without requiring immediate physical contact by the law enforcement officer. The air bag is activated by a control switch in the front seat and inflates to independently restrict the amount of physical activity occurring in the rear seat of the vehicle while allowing the officer to safely stop the vehicle. The air bag can also provide the officer additional time to get backup personnel to aid him if the situation warrants it. The bag is inflated and maintains a constant pressure by an air pump.

  20. The role of integrated resource planning, environmental externalities, and anticipation of future regulation in compliance planning under the Clean Air Act Amendments of 1990

    SciTech Connect

    Bernow, S.; Biewald, B.; Wulfsberg, K.

    1993-07-01

    Utilities are developing sulfur dioxide (SO{sub 2}) emission compliance plans to meet limitations of the Clean Air Act Amendments of 1990 (CAAA). Compliance plans will have long-term effects on resource selection, fuel choice, and system dispatch. Use of integrated resource planning (IRP) is necessary to ensure compliance plans are consistent with the overall societal goals. In particular, environmental externalities must be integrated with the compliance planning process. The focus of the CAAA is on air pollution reduction, specifically acid gases and toxics, and attainment of National Ambient Air Quality Standards (NAAQS) for criteria pollutants. Title IV specifically focuses on sulfur dioxide with a national allowance trading system, while further regulation of toxics and nitrogen oxides is slated for additional study. Yet, compliance planning based narrowly upon today`s environmental regulations could fail to meet the broad goals of IRP if a larger array of environmental externalities is excluded from the analysis. Compliance planning must consider a broad range of environmental effects from energy production and use to (1) protect society`s long-term stake in environmental quality, and (2) ensure that today`s plans are rich enough to accommodate potential changes in regulation and national environmental goals. The explicit recognition of environmental effects, such as those associated with CO{sub 2} release, will result in prudent compliance plans that take advantage of current opportunities for pollution avoidance and have long-term viability in the face of regulatory change. By including such considerations, the mix of resources acquired and operated (supply and demand, existing and new, conventional and renewable, fuel type and fuel quality, pollution control, and dispatch protocols) will be robust and truly least-cost.

  1. Additive Similarity Trees

    ERIC Educational Resources Information Center

    Sattath, Shmuel; Tversky, Amos

    1977-01-01

    Tree representations of similarity data are investigated. Hierarchical clustering is critically examined, and a more general procedure, called the additive tree, is presented. The additive tree representation is then compared to multidimensional scaling. (Author/JKS)

  2. Air transport

    NASA Technical Reports Server (NTRS)

    Page, F Handley

    1924-01-01

    I purpose (sic) in this paper to deal with the development in air transport which has taken place since civil aviation between England and the Continent first started at the end of August 1919. A great deal of attention has been paid in the press to air services of the future, to the detriment of the consideration of results obtained up to the present.

  3. Air Pollution.

    ERIC Educational Resources Information Center

    Fox, Donald L.

    1989-01-01

    Materials related to air pollution are reviewed for the period January 1987, to October 1988. The topics are pollution monitoring, air pollution, and environmental chemistry. The organization consists of two major analytical divisions: (1) gaseous methods; and (2) aerosol and particulate methods. (MVL)

  4. Air Pollution.

    EPA Science Inventory

    Air quality is affected by many types of pollutants that are emitted from various sources, including stationary and mobile. These sources release both criteria and hazardous air pollutants, which cause health effects, ecological harm, and material damage. They are generally categ...

  5. Air pollution effects on the ultrastructure of Phlomis fruticosa mesophyll cells

    SciTech Connect

    Psaras, G.K.; Christodoulakis, N.S.

    1987-04-01

    Plant physiologists and environmental scientists suggest that a basic effect of air pollution on plants leads towards the minimization of their productivity. On the other hand the action of individual pollutants on intact plants has been studied from biochemical as well as structural viewpoint. Thus the study of plant responses to SO/sub 2/ exposure revealed that this agent causes acute and chronic injury. Chronic injury results in chlorosis and subsequent necrosis due to destruction of chlorophylls and final chloroplast lysis. It has been documented that ultrastructural characteristics of leaves are affected prior to any visible injury. Electron microscope examination of SO/sub 2/ fumigated plant-attached leaves of Vicia faba revealed chloroplast thylakoids starting to swell whilst photosynthesis rate was drastically reduced. The first light microscope-detected effects of air pollution on the leaf structure of plants common in natural ecosystems of Athens metropolitan area, have been reported. A chlorosis phenomenon in Urginea maritima leaves as well as an indication of detrimental effects of Phlomis fruticosa mesophyll chloroplasts were documented. In this work further investigation has been undertaken in order to elucidate the precise effects of air pollution on the ultrastructure of the photosynthesizing mesophyll cells.

  6. Proceedings of the Air & Waste Management Association's (A & WMA) 100th annual conference and exhibition

    SciTech Connect

    2007-07-01

    The CD-ROM contains more than 500 full technical presentations from the Air and Waste Management Association's 100th Annual Conference. The 2007 Critical Review 'Will the circle be unbroken? A history of the US national ambient air quality standards' is also included, as well as articles celebrating A & WMA's centennial. Subjects covered include: PM field studies; fine particles; PM measurements; chemical composition of the atmosphere; photochemical process in the atmosphere; short range dispersion; regional model analysis; long range dispersion modeling; noises and vibration; visibility; indoor air quality chemistry and physics; SO{sub 3} and SO{sub 2} control techniques; NOx control; mercury and power generation, technology and control; mercury emissions control, measurement and science; PM2.5 fine particle emission control; CO{sub 2} capture from combustion sources; innovations in control of VOCs and other hazardous emissions; organic vapor capture for recovery, recycling or destruction; biological control of emissions; computer generated inventories; ambient monitoring field studies; satellite remote sensing; MACT developments; particulate matter; environmental compliance at Federal facilities; mercury monitoring in the power generation industry; coal plant and IGCC regulatory and permitting issues; environmental issues facing industry energy; climate change electric power industry perspectives; and climate change and sustainability shortages.

  7. Spring time photochemical air pollution in Osaka

    SciTech Connect

    Wakamatsu, Shinji; Uno, Itsushi; Ohara, Toshimasa

    1996-12-31

    High concentrations of nitrogen dioxide are frequently observed in Osaka area in spring season. To clarify this, a series of three dimensional field observation was conducted in April 1993 covering Osaka and surrounding area. Vertical and horizontal distributions of ozone, NO, NO{sub x}, SO{sub 2}, CO, aerosol species, hydrocarbon species and meteorological parameter such as temperature, uv radiation, wind speed, wind direction are measured on the ground and aloft. Covering the observational period yellow sand transportation from the continent and stratospheric ozone intrusion were also observed under the meteorological condition of moving high pressure system. During the aircraft observation of 19 to 21 April 1993 high concentration of photochemical air pollution was observed aloft over Osaka area. Maximum ozone concentration was me than 150 ppb. Vertical distribution of ozone showed uniform profile up to 2500m in day time. At Mt. Ikoma (600 m) ozone concentration had been almost constant ranging 80-100 ppb throughout the observational period. To clarify this phenomena three dimensional photochemical air pollution simulation model was applied based on the real meteorological and emission conditions. Simulated result showed photochemical reaction play an important role to form the spring time high concentrations of nitrogen dioxide in Osaka.

  8. Solubilities of Peroxyacetyl Nitrate and Peroxynitrate in Water and Aqueous H(sub 2)SO(sub 4)

    NASA Technical Reports Server (NTRS)

    Leu, M. T.; Zhang, R.

    1998-01-01

    In addition, the effective Henry's law constant and the associative enthalpy change of solvation of PNA in water are determined to be 39.95 mol kg^-1 atm^-1 and -69.84 kJ mol^-1 at 298.15K, respectively.

  9. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Pratt, J. R.; St. Clair, T. L.; Burks, H. D.; Stoakley, D. M.

    1987-01-01

    A method has been found for enhancing the melt flow of thermoplastic polyimides during processing. A high molecular weight 422 copoly(amic acid) or copolyimide was fused with approximately 0.05 to 5 pct by weight of a low molecular weight amic acid or imide additive, and this melt was studied by capillary rheometry. Excellent flow and improved composite properties on graphite resulted from the addition of a PMDA-aniline additive to LARC-TPI. Solution viscosity studies imply that amic acid additives temporarily lower molecular weight and, hence, enlarge the processing window. Thus, compositions containing the additive have a lower melt viscosity for a longer time than those unmodified.

  10. [Food additives and healthiness].

    PubMed

    Heinonen, Marina

    2014-01-01

    Additives are used for improving food structure or preventing its spoilage, for example. Many substances used as additives are also naturally present in food. The safety of additives is evaluated according to commonly agreed principles. If high concentrations of an additive cause adverse health effects for humans, a limit of acceptable daily intake (ADI) is set for it. An additive is a risk only when ADI is exceeded. The healthiness of food is measured on the basis of nutrient density and scientifically proven effects.

  11. Results of thioclear testing: Magnesium-lime FGD with high SO{sub 2} removals and salable by-products

    SciTech Connect

    Lani, B.; College, J.; Babu, M.

    1995-06-01

    Wet scrubbing is the leading proven commercial post-combustion FGD technology available to meet the sulfur dioxide reductions required by the Clean Air Act Amendments. To reduce costs associated with wet FGD, Dravo Lime Company has developed the ThioClear process. ThioClear is an ex-situ forced oxidation magnesium-enhanced lime FGD process. The ThioClear process differs from the conventional magnesium-enhanced lime process in that the recycle liquor has minimal suspended solids and the by-products are wallboard quality gypsum and magnesium hydroxide, and excellent reagent for water treatment. The process has demonstrated sulfur dioxide removal efficiencies of 98% in both a vertical spray tower and a horizontal absorber operating at gas velocities of 16 fps and 23 fps, respectively. This paper reports the optimization studies and associated economics from testing being conducted at Dravo Lime Company`s pilot plant located at the Miami Fort Station of The Cincinnati Gas and Electric Company.

  12. Allowance trading under the Clean Air Act: Who should regulate, and when?

    SciTech Connect

    Lock, R.

    1993-07-01

    The goal of this paper is to explore how compliance with the Clean Air Act Amendments of 1990 (CAAA), especially Title IV and emission trading under it, will affect the current relationship between state and federal regulation. It is difficult, with the limited experience we have had under Title IV, to be definitive about or to be a very strong advocate of too many policy positions. What may be most helpful at this point is to identify where the difficult issues in state/federal relations might arise; and then to explore ways in which tensions might be either avoided or resolved. One anticipated conclusion is that a traditional regulatory mindset could be very destructive if applied to this new area of oversight without due sensitivity to what Congress is trying to achieve in Title IV. That concern pervaded the early legislative debates; and it persists today. Title IV presents some unique challenges to state regulators and will require some creative solutions and fresh thinking if the goals of Congress are to be realized and the full benefits that allowance trading can offer are to be reaped by electricity consumers. In the ultimate analysis, Title IV amounts to a massive internalization of the external costs imposed on society by acid rain deposition. (This places in serious question the notion of additional externality {open_quotes}adders{close_quotes} for sulfur dioxide (SO{sub 2}) and nitrous oxide (NO{sub x}) at the state level for utility supply planning purposes.) The whole point of Title IV is to give those directly charged with compliance, namely power producers, the maximum flexibility to pursue least-cost compliance solutions. Perhaps the biggest single factor in how well they do this will be how state regulators respond to their compliance and allowance trading initiatives.

  13. Nanocrystalline Ba{sub 0.97}Ca{sub 0.03}SO{sub 4}:Eu for ion beams dosimetry

    SciTech Connect

    Lochab, S. P.; Kanjilal, D.; Salah, Numan; Habib, Sami S.; Lochab, Jyoti; Ranjan, Ranju; Aleynikov, V. E.; Rupasov, A. A.; Pandey, A.

    2008-08-01

    Nanoparticles of Ba{sub 0.97}Ca{sub 0.03}SO{sub 4}:Eu have been irradiated by 48 MeV Li{sup 3+}, 75 MeV C{sup 6+}, and 90 MeV O{sup 7+} ion beams with a fluence range of 1x10{sup 9}-1x10{sup 13} ion/cm{sup 2}. The thermoluminescence (TL) glow curves along with the response curves of this nanophosphor have been investigated and compared with those of the corresponding microcrystalline samples. TL glow curve of the nanophosphor exposed to {gamma}-rays has also been included in the letter with the aim of reporting some of the comparative measurements. The glow curves of the ion-beam irradiated nanomaterials are similar in their shapes to those induced by gamma rays, with a shift in the peak positions to the higher temperature side by around 30 K. The TL intensity of the ion-beam irradiated nanomaterials is found to decrease, while going from low to high atomic number (Z) ions (i.e., Li{sup 3+}{yields}O{sup 7+}). Similar trend was also observed in the linearity of the TL response curves. The response curve of Li ion irradiated nanomaterials is sublinear in the whole range of studied fluences. C ion has also a more or less similar response, while the O ion has a sublinear response over a shorter range of 1x10{sup 9}-1x10{sup 12} ion/cm{sup 2}, and above this range the response saturates. These results for the nanomaterials are much better than that of the corresponding microcrystalline sample irradiated by Li{sup 3+} ions. The curve was sublinear up to the fluence 1x10{sup 10} ion/cm{sup 2} and then saturates at higher fluences. The wider sublinear TL response of the nanocrystalline Ba{sub 0.97}Ca{sub 0.03}SO{sub 4}:Eu makes it superior to its corresponding microform and thus makes it a suitable candidate as a dosimeter to be used for detecting the doses of ions, especially the Li and C ions for their application in cancer radiotherapy and radiation biology.

  14. F-76 Lubricity Improver Additive Evaluation

    DTIC Science & Technology

    2013-09-16

    steel 8-inch extender tube is attached to the large bung of the drum and a stainless steel, air driven pump is placed into the extender tube. The...drum pump outlet line is then attached onto the 90-degree stainless steel fitting on the small bung of the drum and the additized referee fuel is

  15. 78 FR 16476 - Procurement List Additions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-15

    ... Attendant Service McConnell Air Force Base, KS. NPA: Training, Rehabilitation, & Development Institute, Inc... service and impact of the additions on the current or most recent contractors, the Committee has... following action will not have a significant impact on a substantial number of small entities. The...

  16. Flue gas desulfurization/denitrification using metal-chelate additives

    DOEpatents

    Harkness, J.B.L.; Doctor, R.D.; Wingender, R.J.

    1985-08-05

    A method of simultaneously removing SO/sub 2/ and NO from oxygen-containing flue gases resulting from the combustion of carbonaceous material by contacting the flue gas with an aqueous scrubber solution containing an aqueous sulfur dioxide sorbent and an active metal chelating agent which promotes a reaction between dissolved SO/sub 2/ and dissolved NO to form hydroxylamine N-sulfonates. The hydroxylamine sulfonates are then separated from the scrubber solution which is recycled. 3 figs.

  17. Flue gas desulfurization/denitrification using metal-chelate additives

    DOEpatents

    Harkness, John B. L.; Doctor, Richard D.; Wingender, Ronald J.

    1986-01-01

    A method of simultaneously removing SO.sub.2 and NO from oxygen-containing flue gases resulting from the combustion of carbonaceous material by contacting the flue gas with an aqueous scrubber solution containing an aqueous sulfur dioxide sorbent and an active metal chelating agent which promotes a reaction between dissolved SO.sub.2 and dissolved NO to form hydroxylamine N-sulfonates. The hydroxylamine sulfonates are then separated from the scrubber solution which is recycled.

  18. Evaluation of indoor air pollution and its effect on human health in Beijing's rural areas

    SciTech Connect

    Hu, Hansheng; Liu, Youcheng )

    1989-01-01

    Average exposures to SO{sub 2}, NO{sub 2}, CO{sub 2}, CO, Inhalable Particles (IP), common bacteria and streptococci were monitored in 1986 in 24 new and old village households in the northern suburb of Beijing. Four hundred and fifty school children were also measured and observed for chronic and acute respiratory symptoms and illnesses, pulmonary function, immune response, carboxyhemoglobin level and eye response time to signals so as to evaluate the effects of rural indoor air pollution on human health. The results of air monitoring data showed that the new heating systems were effective in reducing the indoor concentrations of the measured pollutants by 23 to 76% in winter, but present concentrations still exceed China's Standard because of inadequate house design. Health outcomes suggested that children in the new village demonstrated signs of improvement for better health. The implications of different factors affecting indoor air pollution are evaluated and discussed.

  19. Commercial demonstration of the NOXSO SO{sub 2}/NO{sub x} removal flue gas cleanup system. Quarterly technical progress report No. 16, December 1, 1994--February 28, 1995

    SciTech Connect

    1995-12-31

    The NOXSO process is a dry, post-combustion flue gas treatment technology which uses a regenerable sorbent to simultaneously adsorb sulfur dioxide (SO{sub 2}) and nitrogen oxides (NO{sub x}) from flue gas. In the process, the SO{sub 2} is converted to a sulfur by- product (elemental sulfur, sulfuric acid, or liquid SO{sub 2}) and the NO{sub x} is converted to nitrogen and oxygen. The objective of the NOXSO Clean Coal Project is to design, construct, and operate a flue gas treatment system utilizing the NOXSO process at Alcoa Generating Corporation`s (AGC) Warrick Power Plant. The NOXSO plant is being designed to remove 98% of the SO{sub 2} and 75% of the NO{sub x} from the flue gas from the 150-MW equivalent, unit 2 boiler. The by-product to be generated by the project is liquid SO{sub 2}. Sufficient construction cost and operating data will be obtained during the project to confirm the process economics and provide a basis to guarantee performance on a commercial scale. The project is in the Front End Engineering/Environmental Evaluation Phase. Engineering activities are approximately 20% complete and activities to update the project estimate based on completed engineering and equipment bids have been initiated. Process study activities include laboratory fluid-bed adsorber studies, regenerator computer model development and studies, fluid-flow modelling in fluid-bed vessels, and evaluations of SO{sub 2} production processes. The laboratory- scale, fluid-bed adsorber studies are being conducted to improve the accuracy of the removal efficiency predictions and study the impact of adding a third adsorber stage. The construction of the steel, multi-stage reactor is currently underway. The regenerator computer model was revised and is being used to study design options for improving the regenerator performance. Fluid-flow modelling has been conducted to study the effect of grid supports on the gas flow inside the fluid bed vessels.

  20. Air Apparent.

    ERIC Educational Resources Information Center

    Harbster, David A.

    1988-01-01

    Explains the principle upon which a barometer operates. Describes how to construct two barometric devices for use in the classroom that show air's changing pressure. Cites some conditions for predicting weather. (RT)

  1. Air Abrasion

    MedlinePlus

    ... information you need from the Academy of General Dentistry Sunday, April 9, 2017 About | Contact InfoBites Quick ... general dentist, who has been trained in restorative dentistry techniques, will perform any procedures that use air- ...

  2. Polylactides in additive biomanufacturing.

    PubMed

    Poh, Patrina S P; Chhaya, Mohit P; Wunner, Felix M; De-Juan-Pardo, Elena M; Schilling, Arndt F; Schantz, Jan-Thorsten; van Griensven, Martijn; Hutmacher, Dietmar W

    2016-12-15

    New advanced manufacturing technologies under the alias of additive biomanufacturing allow the design and fabrication of a range of products from pre-operative models, cutting guides and medical devices to scaffolds. The process of printing in 3 dimensions of cells, extracellular matrix (ECM) and biomaterials (bioinks, powders, etc.) to generate in vitro and/or in vivo tissue analogue structures has been termed bioprinting. To further advance in additive biomanufacturing, there are many aspects that we can learn from the wider additive manufacturing (AM) industry, which have progressed tremendously since its introduction into the manufacturing sector. First, this review gives an overview of additive manufacturing and both industry and academia efforts in addressing specific challenges in the AM technologies to drive toward AM-enabled industrial revolution. After which, considerations of poly(lactides) as a biomaterial in additive biomanufacturing are discussed. Challenges in wider additive biomanufacturing field are discussed in terms of (a) biomaterials; (b) computer-aided design, engineering and manufacturing; (c) AM and additive biomanufacturing printers hardware; and (d) system integration. Finally, the outlook for additive biomanufacturing was discussed.

  3. Additive Manufactured Product Integrity

    NASA Technical Reports Server (NTRS)

    Waller, Jess; Wells, Doug; James, Steve; Nichols, Charles

    2017-01-01

    NASA is providing key leadership in an international effort linking NASA and non-NASA resources to speed adoption of additive manufacturing (AM) to meet NASA's mission goals. Participants include industry, NASA's space partners, other government agencies, standards organizations and academia. Nondestructive Evaluation (NDE) is identified as a universal need for all aspects of additive manufacturing.

  4. Volcanic gas emissions and their effect on ambient air character

    SciTech Connect

    Sutton, A.J.; Elias, T.

    1994-01-01

    This bibliography was assembled to service an agreement between Department of Energy and the USGS to provide a body of references and useful annotations for understanding background gas emissions from Kilauea volcano. The current East Rift Zone (ERZ) eruption of Kilauea releases as much as 500,000 metric tonnes of SO{sub 2} annually, along with lesser amounts of other chemically and radiatively active species including H{sub 2}S, HCl, and HF. Primary degassing locations on Kilauea are located in the summit caldera and along the middle ERZ. The effects of these emissions on ambient air character are a complex function of chemical reactivity, source geometry and effusivity, and local meteorology. Because of this complexity, we organized the bibliography into three main sections: (1) characterizing gases as they leave the edifice; (2) characterizing gases and chemical reaction products away from degassing sources; and (3) Hawaii Island meteorology.

  5. Studies of chemical reduction of Fe(III)*EDTA in an SO{sub 2}/NO{sub x} aqueous scrubber system

    SciTech Connect

    Li, W.; Keener, T.C.; Mendelsohn, M.; Harkness, J.B.L.; Livengood, C.D.

    1996-03-01

    Ferrous*EDTA has been found to be an effective scrubbing agent for nitric oxide gas. A major process problem is oxidation of the iron to the ferric species, leading to a significant decrease in NO{sub x}-removal capability. Argonne National Laboratory discovered a class of organic compounds that, when used with ferrous*EDTA in a sodium carbonate chemistry, could maintain high levels of NO{sub x} removal. However, those antioxidant/reducing agents (A/R) are not effective in a lime-based chemistry. In recent reports, it has been found that ascorbic acid and related compounds are capable of maintaining stable NO{sub x} removals of about 50% (compared with about 15% without the agent) in a lime-based FGD chemistry with Fe(II)*EDTA. It is believed that the improved performance of Fe(II)*EDTA is due to the catalytic action of ascorbate in the Fe(III)*EDTA reduction system, where Fe(III)*EDTA is reduced by ascorbate and oxidized ascorbate is then reduced back to the ascorbate by sulfite/bisulfite anions, which come from the dissolution of SO{sub 2} in the flue gas. In the present work, the kinetics of the reduction of ferric chelate by ascorbate and reduction of oxidized ascorbate by sulfite/bisulfite anions at a typical flue-gas scrubber-system operating temperature ({approximately}55 C) have been determined.

  6. Use of aromatic salts for simultaneously removing SO.sub.2 and NO.sub.x pollutants from exhaust of a combustion system

    DOEpatents

    Levendis, Yiannis A.; Wise, Donald L.

    1994-10-04

    A method is disclosed for removing pollutants from the exhaust of combustion systems burning fuels containing substantial amounts of sulfur and nitrogen. An exemplary method of the invention involves the formation and reaction of a sorbent comprising calcium benzoate. The calcium benzoate is either dry-sprayed (in the form of a fine powder) or wet-sprayed in an aqueous solution in a high temperature environment such as a combustion chamber. The latter technique is feasible since calcium benzoate is a water-soluble form of calcium. When the dispersed particles of calcium benzoate are heated to a high temperature, the organic benzoate burns off and fine calcium oxide particles are formed. These particles are cenospheric (hollow) and have thin and highly porous walls, thus, affording optimum external and internal accessibility for reacting with toxic gaseous emissions such as SO.sub.2. Further, the combustion of the organic benzoate portion of the sorbent results in the conversion of NO.sub.x to N.sub.2.

  7. {sup 33}S hyperfine interactions in H{sub 2}S and SO{sub 2} and revision of the sulfur nuclear magnetic shielding scale

    SciTech Connect

    Helgaker, Trygve; Gauss, Jürgen; Cazzoli, Gabriele Puzzarini, Cristina

    2013-12-28

    Using the Lamb-dip technique, the hyperfine structure in the rotational spectra of H{sub 2}{sup 33}S and {sup 33}SO{sub 2} has been resolved and the corresponding parameters—that is, the sulfur quadrupole-coupling and spin–rotation tensors—were determined. The experimental parameters are in good agreement with results from high-level coupled-cluster calculations, provided that up to quadruple excitations are considered in the cluster operator, sufficiently large basis sets are used, and vibrational corrections are accounted for. The {sup 33}S spin-rotation tensor for H{sub 2}S has been used to establish a new sulfur nuclear magnetic shielding scale, combining the paramagnetic part of the shielding as obtained from the spin–rotation tensor with a calculated value for the diamagnetic part as well as computed vibrational and temperature corrections. The value of 716(5) ppm obtained in this way for the sulfur shielding of H{sub 2}S is in good agreement with results from high-accuracy quantum-chemical calculations but leads to a shielding scale that is about 28 ppm lower than the one suggested previously in the literature, based on the {sup 33}S spin-rotation constant of OCS.

  8. High temperature membranes for H{sub 2}S and SO{sub 2} separations. Quarterly progress report, October 1, 1992--December 31, 1992

    SciTech Connect

    Winnick, J.

    1992-12-31

    Successful removal of SO{sub x} from flue gas depends on the development of a membrane able to achieve a current density of 50 mA/cm{sup 2} at a total voltage of approximately 1V. Flooding of electrode has been identified as a problem, leading to increasing polarization over time. The resulting reduction of surface area also tends to limit the mass transfer flux, reducing the efficiency of the cell. To reduce flooding, new materials and techniques of manufacture will be investigated, in the attempt to produce a ceramic membrane of approximately 50% theoretical density. This membrane must have proper pore size distribution to ensure sufficient capillary force to prevent impregnated electrolyte from flooding electrodes, and subsequently drying the ceramic membrane. Various methods of matrix production were studied this quarter: tape casting, pressing and sintering, and slip casting. Each will be discussed in turn. Electrolyte introduction to the cell is a continuing problem. The development of a method is still being investigated. Ideally, the electrolyte would be introduced as powder with binder in a green body. This binder would burn away at temperatures of approximately 300{degrees}C, leaving pure electrolyte to melt and complete the ionic path necessary for the electrochemical cell. The electrolyte used this quarter was, exclusively, a 90 wt % K{sub 2}S{sub 2}O{sub 7}/10 wt % V{sub 2}O{sub 5} mixture.

  9. Examination of utility Phase 1 compliance choices and state reactions to Title IV of the Clean Air Act Amendments of 1990

    SciTech Connect

    Bailey, K.A.; Elliott, T.J.; Carlson, L.J.; South, D.W.

    1993-11-01

    Title IV (acid rain) of the Clean Air Act Amendments of 1990 is imposing new limitations on the emission of sulfur dioxide (SO{sub 2}) and nitrogen oxides (N{sub x}) from electric power plants. The act requires utilities to develop compliance plans to reduce these emissions, and indications are that these plans will dramatically alter traditional operating procedures. A key provision of the SO{sub 2} control program deaned in Title IV is the creation of a system of emission allowances, with utilities having the option of complying by adjusting system emissions and allowance holdings. A compilation of SO{sub 2} compliance activities by the 110 utility plants affected by Phase I is summarized in this report. These compliance plans are presented in a tabular form, correlated with age, capacity, and power pool data. A large number of the Phase I units (46%) have chosen to blend or switch to lower sulfur coals. This choice primarily is in response to (1) prices of low-sulfur coal and (2) the need to maintain SO{sub 2} control flexibility because of uncertain future environmental regulations (e.g., air toxics, carbon dioxide) and compliance prices. The report also discusses the responses of state legislatures and public utility commissions to the compliance requirements in Title IV. Most states have taken negligible action regarding the regulatory treatment of allowances and compliance activities. To protect mine employment, states producing high-sulfur coal have enacted regulations encouraging continued use of that coal, but for the most part, this response has had little effect on utility compliance choices.

  10. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Fletcher, James C. (Inventor); Pratt, J. Richard (Inventor); St.clair, Terry L. (Inventor); Stoakley, Diane M. (Inventor); Burks, Harold D. (Inventor)

    1992-01-01

    A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA.

  11. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Pratt, J. Richard (Inventor); St.clair, Terry L. (Inventor); Stoakley, Diane M. (Inventor); Burks, Harold D. (Inventor)

    1993-01-01

    A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of the additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA.

  12. Air Cleaning Technologies

    PubMed Central

    2005-01-01

    Executive Summary Objective This health technology policy assessment will answer the following questions: When should in-room air cleaners be used? How effective are in-room air cleaners? Are in-room air cleaners that use combined HEPA and UVGI air cleaning technology more effective than those that use HEPA filtration alone? What is the Plasmacluster ion air purifier in the pandemic influenza preparation plan? The experience of severe acute respiratory syndrome (SARS) locally, nationally, and internationally underscored the importance of administrative, environmental, and personal protective infection control measures in health care facilities. In the aftermath of the SARS crisis, there was a need for a clearer understanding of Ontario’s capacity to manage suspected or confirmed cases of airborne infectious diseases. In so doing, the Walker Commission thought that more attention should be paid to the potential use of new technologies such as in-room air cleaning units. It recommended that the Medical Advisory Secretariat of the Ontario Ministry of Health and Long-Term Care evaluate the appropriate use and effectiveness of such new technologies. Accordingly, the Ontario Health Technology Advisory Committee asked the Medical Advisory Secretariat to review the literature on the effectiveness and utility of in-room air cleaners that use high-efficiency particle air (HEPA) filters and ultraviolet germicidal irradiation (UVGI) air cleaning technology. Additionally, the Ontario Health Technology Advisory Committee prioritized a request from the ministry’s Emergency Management Unit to investigate the possible role of the Plasmacluster ion air purifier manufactured by Sharp Electronics Corporation, in the pandemic influenza preparation plan. Clinical Need Airborne transmission of infectious diseases depends in part on the concentration of breathable infectious pathogens (germs) in room air. Infection control is achieved by a combination of administrative, engineering

  13. S-OO bond dissociation energies and enthalpies of formation of the thiomethyl peroxyl radicals CH{sub 3}S(O){sub n}OO (n=0,1,2)

    SciTech Connect

    Salta, Zoi; Kosmas, Agnie Mylona; Lesar, Antonija

    2014-10-06

    Optimized geometries, S-OO bond dissociation energies and enthalpies of formation for a series of thiomethyl peroxyl radicals are investigated using high level ab initio and density functional theory methods. The results show that the S-OO bond dissociation energy is largest in the methylsulfonyl peroxyl radical, CH{sub 3}S(O){sub 2}OO, which contains two sulfonic type oxygen atoms followed by the methylthiyl peroxyl radical, CH{sub 3}SOO. The methylsulfinyl peroxyl radical, CH{sub 3}S(O)OO, which contains only one sulfonic type oxygen shows the least stability with regard to dissociation to CH{sub 3}S(O)+O{sub 2}. This stabilization trend is nicely reflected in the variations of the S-OO bond distance which is found to be shortest in CH{sub 3}S(O){sub 2}OO and longest in CH{sub 3}S(O)OO.

  14. Food Additives and Hyperkinesis

    ERIC Educational Resources Information Center

    Wender, Ester H.

    1977-01-01

    The hypothesis that food additives are causally associated with hyperkinesis and learning disabilities in children is reviewed, and available data are summarized. Available from: American Medical Association 535 North Dearborn Street Chicago, Illinois 60610. (JG)

  15. Smog control fuel additives

    SciTech Connect

    Lundby, W.

    1993-06-29

    A method is described of controlling, reducing or eliminating, ozone and related smog resulting from photochemical reactions between ozone and automotive or industrial gases comprising the addition of iodine or compounds of iodine to hydrocarbon-base fuels prior to or during combustion in an amount of about 1 part iodine per 240 to 10,000,000 parts fuel, by weight, to be accomplished by: (a) the addition of these inhibitors during or after the refining or manufacturing process of liquid fuels; (b) the production of these inhibitors for addition into fuel tanks, such as automotive or industrial tanks; or (c) the addition of these inhibitors into combustion chambers of equipment utilizing solid fuels for the purpose of reducing ozone.

  16. High-throughput and microwave investigation of rare earth phosphonatoethanesulfonates-Ln(O{sub 3}P-C{sub 2}H{sub 4}-SO{sub 3}) (Ln=Ho, Er, Tm, Yb, Lu, Y)

    SciTech Connect

    Sonnauer, Andreas

    2008-11-15

    Following the strategy of using bifunctional phosphonic acids for the synthesis of new metal phosphonates, the flexible ligand 2-phosphonoethanesulfonic acid, H{sub 2}O{sub 3}P-C{sub 2}H{sub 4}-SO{sub 3}H (H{sub 3}L), was used in a high-throughput (HT) and microwave investigation of rare earth phosphonatoethanesulfonates. The HT-investigation led to six isotypic compounds Ln(O{sub 3}P-C{sub 2}H{sub 4}-SO{sub 3}) with Ln=Ho (1), Er (2), Tm (3), Yb (4), Lu (5) and Y (6). The syntheses were scaled-up in glass reactor tubes in order to obtain larger amounts for a detailed characterization. Based on these results all compounds could be also synthesized by microwave-assisted heating and the influence of reaction time and stirring rate during the synthesis was established. For compound 2 the crystal structure was determined by single-crystal X-ray diffraction. The compounds contain isolated slightly distorted LnO{sub 6} octahedra that are connected by the phosphonate and sulfonate groups into a three-dimensional framework. Thermogravimetric investigations demonstrate the high thermal stability of the compounds up to 460 deg. C. - Graphical abstract: A high-throughput and microwave investigation of the System LnX{sub 3}/H{sub 2}O{sub 3}P-C{sub 2}H{sub 4}-SO{sub 3}/NaOH/H{sub 2}O led to six new compounds Ln(O{sub 3}P-C{sub 2}H{sub 4}-SO{sub 3}) with Ln=Ho, Er, Tm, Yb, Lu, Y.

  17. Emissions R&D at GE/CRD coal-fueled diesel: Technology development methods for SO{sub 2} and NO{sub x} removal from coal diesel exhaust

    SciTech Connect

    Cohen, M.R.; Leonard, G.L.; Slaughter, D.M.

    1993-10-01

    Four processes were investigated at the GE Research and Development Center (GE-CRD) for the removal of gaseous pollutants from the exhaust of a coal-fired diesel locomotive engine. The minimum goal for emissions control was to reduce the pollutant levels at least to the levels of a conventional diesel engine. It should be noted, however, that some of the methods investigated were capable of reducing emissions below these levels. Achieving the minimum goal requires a reduction of approximately 50% in SO{sub 2} emissions and a 90 to 95% reduction in particulate emissions, the actual percentages varying with the fuel. NO{sub x} emissions from the coal diesel are approximately 50% of the conventional diesel level. The space limitations on board the locomotive present the greatest obstacle to the design of an emissions control system. The cleanup system must be compact as well as multifunctional. The development of a particulate collection device was undertaken by GE Environmental Services, Inc. (GEESI). Among the options they evaluated were high-temperature metal filters, cyclones, and a granular bed. The development of a cleanup method or SO{sub 2} and possibly NO{sub x} was undertaken at GE-CRD. A process was sought which could incorporate one of the particulate removal devices under consideration. Four processes utilizing three classes of sorbents -- copper oxide, calcium-based, and sodium bicarbonate --were investigated for SO{sub 2} capture: Two of these processes use copper oxide (CuO), a regenerable SO{sub 2} sorbent. The CuSO{sub 4} formed has the added property that it catalyzes the reduction of NO{sub x} to N{sub 2} in the presence of NH{sub 3}. This NO{sub x} removal capability was tested for both CuO processes.

  18. Implications of air pollution effects on athletic performance

    SciTech Connect

    Pierson, W.E.; Covert, D.S.; Koenig, J.Q.; Namekata, T.; Kim, Y.S.

    1986-06-01

    Both controlled human studies and observational studies suggest that air pollution adversely affects athletic performance during both training and competition. The air pollution dosage during exercise is much higher than during rest because of a higher ventilatory rate and both nasal and oral breathing in the former case. For example, sulfur dioxide, which is a highly water-soluble gas, is almost entirely absorbed in the upper respiratory tract during nasal breathing. However, with oral pharyngeal breathing, the amount of sulfur dioxide that is absorbed is significantly less, and with exercise and oral pharyngeal breathing a significant decrease in upper airway absorption occurs, resulting in a significantly larger dosage of this pollutant being delivered to the tracheobronchial tree. Recently, several controlled human studies have shown that the combination of exercise and pollutant exposure (SO/sub 2/ or O/sub 3/) caused a marked bronchoconstriction and reduced ventilatory flow when compared to pollution exposure at rest. In a situation like the Olympic Games where milliseconds and millimeters often determine the success of athletes, air pollution can be an important factor in affecting their performance. This paper examines possible impacts of air pollution on athletic competition.

  19. Recent trends of energy consumption and air pollution in China

    SciTech Connect

    Tian, H.Z.; Hao, J.M.; Hu, M.Y.; Nie, Y.F.

    2007-03-15

    The relationship between air pollution and energy consumption is a hot topic that is receiving increased attention by industry, regulatory agencies, as well as the public. China is currently undergoing a profound economic and social transition. Since the late 1990s, China's energy production and consumption have undergone an unexpectedly precipitous up-and-down fluctuation, and the related air pollution has changed dramatically. In this study, energy use and the related air pollution during the past years are analyzed and discussed in detail. Further, suggestions on sustainable energy use, air pollution control, as well as CO{sub 2}, abatement are proposed. By 2003, the total primary energy consumption of China had reached 1678.00 million tons (MT) of standard coal equivalent. As a result, emissions of SO{sub 2}, and NOx increased to 21.58 and 16.13 MT in 2003, respectively. Acid rain pollution worsened nationwide after 2000, with the areas of acid rain remaining stable while some seriously acid rain polluted areas worsened. This implies that more rigorous regulations, standards, and effective economic policies are needed.

  20. Additive interaction between heterogeneous environmental ...

    EPA Pesticide Factsheets

    BACKGROUND Environmental exposures often occur in tandem; however, epidemiological research often focuses on singular exposures. Statistical interactions among broad, well-characterized environmental domains have not yet been evaluated in association with health. We address this gap by conducting a county-level cross-sectional analysis of interactions between Environmental Quality Index (EQI) domain indices on preterm birth in the Unites States from 2000-2005.METHODS: The EQI, a county-level index constructed for the 2000-2005 time period, was constructed from five domain-specific indices (air, water, land, built and sociodemographic) using principal component analyses. County-level preterm birth rates (n=3141) were estimated using live births from the National Center for Health Statistics. Linear regression was used to estimate prevalence differences (PD) and 95% confidence intervals (CI) comparing worse environmental quality to the better quality for each model for a) each individual domain main effect b) the interaction contrast and c) the two main effects plus interaction effect (i.e. the “net effect”) to show departure from additive interaction for the all U.S counties. Analyses were also performed for subgroupings by four urban/rural strata. RESULTS: We found the suggestion of antagonistic interactions but no synergism, along with several purely additive (i.e., no interaction) associations. In the non-stratified model, we observed antagonistic interac

  1. Investigation of the structure and properties of K{sub 9}H{sub 7}(SO{sub 4}){sub 8} {center_dot} H{sub 2}O single crystals

    SciTech Connect

    Makarova, I. P. Chernaya, T. S.; Grebenev, V. V.; Dolbinina, V. V.; Verin, I. A.; Simonov, A. A.

    2011-11-15

    The features of the conductivity of K{sub 9}H{sub 7}(SO{sub 4}){sub 8} {center_dot} H{sub 2}O single-crystal samples in the temperature range of superprotonic phase transition have been investigated. The K{sub 9}H{sub 7}(SO{sub 4}){sub 8} {center_dot} H{sub 2}O crystal structure is determined and refined taking into account hydrogen atoms by X-ray diffraction analysis at a temperature of 295 K: monoclinic symmetry, sp. gr. P2{sub 1}/c, Z = 4, a = 7.059(1), b = 19.773(1), c = 23.449(1) Angstrom-Sign , {beta} = 95.33(1) Degree-Sign , R{sub 1}/wR{sub 2} = 2.71/1.71. The structural data obtained suggest that the occurrence of high conductivity in K{sub 9}H{sub 7}(SO{sub 4}){sub 8} {center_dot} H{sub 2}O crystals with an increase in temperature is related to the diffusion of crystallization water and motion of K ions, as well as to the transformation of the system of hydrogen bonds and protonic motion. The stabilization of the high-temperature superprotonic phase and its supercooling to low temperatures are due to the presence of channels for the motion of K ions and slow backward diffusion of water in the crystal.

  2. Hazardous Air Pollutants

    MedlinePlus

    ... Air Toxics Website Rules and Implementation Related Information Air Quality Data and Tools Clean Air Act Criteria Air ... Resources Visibility and Haze Voluntary Programs for Improving Air Quality Contact Us to ask a question, provide feedback, ...

  3. Effects of the 1990 Clean Air Act amendments on distributions of visual impairment

    SciTech Connect

    Shannon, J.D.; Camp, J.; Trexler, E.C. Jr.

    1996-02-01

    The Acid Rain Provisions (Title IV) of the 1990 Clean Air Act Amendments (1990 CAAA) focus on emission policies designed to reduce the amount of deposition of acidifying pollutants, particularly in the Northeast. The primary strategy is a significant reduction in SO{sub 2} emissions, with lesser reductions scheduled for NO{sub {times}} emissions. However, lessening of acid deposition is not the only important benefit of the emission control strategy. Decreasing SO{sup {minus}} and NO {sup {minus}} emissions will decrease atmospheric concentrations of sulfate and nitrate particles, which account for much of the visibility reduction associated with regional haze. Although one can get a qualitative sense of how visibility might improve by examining historical large-scale trends in regional emission totals and regional visibility, quantification of the expected improvement requires model simulations. One must model the spatial and temporal patterns of emissions reductions; the relevant pollutant transport, transformation, and removal processes in the atmosphere; and the changes in particulate loading. For this initial examination of the visibility improvement at Shenandoah National Park associated the the Phase I and Phase II SO{sub 2} emission reductions, we have linked emission trend projections taken from ongoing analysis of the 1990 CAAA at Argonne National Laboratory, regional transport modeling with the Advanced Statistical Trajectory Regional Air Pollution (ASTRAP) model and visual impairment modeling with the Visibility Assessment Scoping Model (VASM).

  4. Air surveillance

    SciTech Connect

    Patton, G.W.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the air surveillance and monitoring programs currently in operation at that Hanford Site. Atmospheric releases of pollutants from Hanford to the surrounding region are a potential source of human exposure. For that reason, both radioactive and nonradioactive materials in air are monitored at a number of locations. The influence of Hanford emissions on local radionuclide concentrations was evaluated by comparing concentrations measured at distant locations within the region to concentrations measured at the Site perimeter. This section discusses sample collection, analytical methods, and the results of the Hanford air surveillance program. A complete listing of all analytical results summarized in this section is reported separately by Bisping (1995).

  5. Group Sparse Additive Models

    PubMed Central

    Yin, Junming; Chen, Xi; Xing, Eric P.

    2016-01-01

    We consider the problem of sparse variable selection in nonparametric additive models, with the prior knowledge of the structure among the covariates to encourage those variables within a group to be selected jointly. Previous works either study the group sparsity in the parametric setting (e.g., group lasso), or address the problem in the nonparametric setting without exploiting the structural information (e.g., sparse additive models). In this paper, we present a new method, called group sparse additive models (GroupSpAM), which can handle group sparsity in additive models. We generalize the ℓ1/ℓ2 norm to Hilbert spaces as the sparsity-inducing penalty in GroupSpAM. Moreover, we derive a novel thresholding condition for identifying the functional sparsity at the group level, and propose an efficient block coordinate descent algorithm for constructing the estimate. We demonstrate by simulation that GroupSpAM substantially outperforms the competing methods in terms of support recovery and prediction accuracy in additive models, and also conduct a comparative experiment on a real breast cancer dataset.

  6. Additive Manufacturing Infrared Inspection

    NASA Technical Reports Server (NTRS)

    Gaddy, Darrell

    2014-01-01

    Additive manufacturing is a rapid prototyping technology that allows parts to be built in a series of thin layers from plastic, ceramics, and metallics. Metallic additive manufacturing is an emerging form of rapid prototyping that allows complex structures to be built using various metallic powders. Significant time and cost savings have also been observed using the metallic additive manufacturing compared with traditional techniques. Development of the metallic additive manufacturing technology has advanced significantly over the last decade, although many of the techniques to inspect parts made from these processes have not advanced significantly or have limitations. Several external geometry inspection techniques exist such as Coordinate Measurement Machines (CMM), Laser Scanners, Structured Light Scanning Systems, or even traditional calipers and gages. All of the aforementioned techniques are limited to external geometry and contours or must use a contact probe to inspect limited internal dimensions. This presentation will document the development of a process for real-time dimensional inspection technique and digital quality record of the additive manufacturing process using Infrared camera imaging and processing techniques.

  7. Phenylethynyl Containing Reactive Additives

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Smith, Joseph G., Jr. (Inventor); Hergenrother, Paul M. (Inventor)

    2002-01-01

    Phenylethynyl containing reactive additives were prepared from aromatic diamine, containing phenylethvnvl groups and various ratios of phthalic anhydride and 4-phenylethynviphthalic anhydride in glacial acetic acid to form the imide in one step or in N-methyl-2-pvrrolidinone to form the amide acid intermediate. The reactive additives were mixed in various amounts (10% to 90%) with oligomers containing either terminal or pendent phenylethynyl groups (or both) to reduce the melt viscosity and thereby enhance processability. Upon thermal cure, the additives react and become chemically incorporated into the matrix and effect an increase in crosslink density relative to that of the host resin. This resultant increase in crosslink density has advantageous consequences on the cured resin properties such as higher glass transition temperature and higher modulus as compared to that of the host resin.

  8. Fused Lasso Additive Model

    PubMed Central

    Petersen, Ashley; Witten, Daniela; Simon, Noah

    2016-01-01

    We consider the problem of predicting an outcome variable using p covariates that are measured on n independent observations, in a setting in which additive, flexible, and interpretable fits are desired. We propose the fused lasso additive model (FLAM), in which each additive function is estimated to be piecewise constant with a small number of adaptively-chosen knots. FLAM is the solution to a convex optimization problem, for which a simple algorithm with guaranteed convergence to a global optimum is provided. FLAM is shown to be consistent in high dimensions, and an unbiased estimator of its degrees of freedom is proposed. We evaluate the performance of FLAM in a simulation study and on two data sets. Supplemental materials are available online, and the R package flam is available on CRAN. PMID:28239246

  9. Phenylethynyl Containing Reactive Additives

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Smith, Joseph G., Jr. (Inventor); Hergenrother, Paul M. (Inventor)

    2002-01-01

    Phenylethynyl containing reactive additives were prepared from aromatic diamines containing phenylethynyl groups and various ratios of phthalic anhydride and 4-phenylethynylphthalic anhydride in glacial acetic acid to form the imide in one step or in N-methyl-2-pyrrolidi none to form the amide acid intermediate. The reactive additives were mixed in various amounts (10% to 90%) with oligomers containing either terminal or pendent phenylethynyl groups (or both) to reduce the melt viscosity and thereby enhance processability. Upon thermal cure, the additives react and become chemically incorporated into the matrix and effect an increase in crosslink density relative to that of the host resin. This resultant increase in crosslink density has advantageous consequences on the cured resin properties such as higher glass transition temperature and higher modulus as compared to that of the host resin.

  10. New ESP additive controls particulates

    SciTech Connect

    Durham, M.D.; Baldrey, K.E.; Bustard, C.J.; Martin, C.E.; Dharmarajan, N.N.

    1997-06-01

    This article reports that a conditioning agent enhanced precipitator performance after plant switched to low-sulfur coal. Firing low-sulfur coal at a power plant designed for medium- or high-sulfur coal will impact the downstream particulate control device. Since the performance of an electro-static precipitator (ESP) is a strong function of the sulfur content in the coal, switching to a low-sulfur coal will severely impact collection efficiency. Particle resistivity is the dominant parameter affecting the performance of an ESP. When the resistivity is too high, the ESP must be increased in size by a factor of two to three, resulting in proportionally increased capital and operating costs. Fly ash from low-sulfur coal is known to have a typical resistivity one or two orders of magnitude above that for ideal collection efficiency in a well-designed ESP. Therefore, when a utility burning a medium- or high-sulfur coal switches to a low-sulfur coal, the increase in particle resistivity resulting from the reduced SO{sub 3} concentration will lead to severe problems in the ESP. There have been many instances where utilities have switched from a high- to a low-sulfur coal, and the problems caused by the increased resistivity have had such a devastating effect on the performance of the ESP that emissions have increased by a factor of 10.

  11. Additives in plastics.

    PubMed Central

    Deanin, R D

    1975-01-01

    The polymers used in plastics are generally harmless. However, they are rarely used in pure form. In almost all commercial plastics, they are "compounded" with monomeric ingredients to improve their processing and end-use performance. In order of total volume used, these monomeric additives may be classified as follows: reinforcing fibers, fillers, and coupling agents; plasticizers; colorants; stabilizers (halogen stabilizers, antioxidants, ultraviolet absorbers, and biological preservatives); processing aids (lubricants, others, and flow controls); flame retardants, peroxides; and antistats. Some information is already available, and much more is needed, on potential toxicity and safe handling of these additives during processing and manufacture of plastics products. PMID:1175566

  12. Additives in plastics.

    PubMed

    Deanin, R D

    1975-06-01

    The polymers used in plastics are generally harmless. However, they are rarely used in pure form. In almost all commercial plastics, they are "compounded" with monomeric ingredients to improve their processing and end-use performance. In order of total volume used, these monomeric additives may be classified as follows: reinforcing fibers, fillers, and coupling agents; plasticizers; colorants; stabilizers (halogen stabilizers, antioxidants, ultraviolet absorbers, and biological preservatives); processing aids (lubricants, others, and flow controls); flame retardants, peroxides; and antistats. Some information is already available, and much more is needed, on potential toxicity and safe handling of these additives during processing and manufacture of plastics products.

  13. Biobased lubricant additives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fully biobased lubricants are those formulated using all biobased ingredients, i.e. biobased base oils and biobased additives. Such formulations provide the maximum environmental, safety, and economic benefits expected from a biobased product. Currently, there are a number of biobased base oils that...

  14. More Than Additional Space...

    ERIC Educational Resources Information Center

    CEFP Journal, 1973

    1973-01-01

    A much needed addition to the Jamestown Elementary School turned out to be more than an expansion of walls for more space. A new educational program, a limited budget, and a short time line were tackled on a team approach basis and were successfully resolved. (Author)

  15. Air Pollution.

    ERIC Educational Resources Information Center

    Scorer, Richard S.

    The purpose of this book is to describe the basic mechanisms whereby pollution is transported and diffused in the atmosphere. It is designed to give practitioners an understanding of basic mechanics and physics so they may have a correct basis on which to formulate their decisions related to practical air pollution control problems. Since many…

  16. Fouling control in seawater by on-line acid addition

    SciTech Connect

    Salvago, G.; Taccani, G.; Polimeni, R.; Fumagalli, G.; Picenoni, D.

    1996-11-01

    An experimental plant was set up containing once-through test lines supplied with seawater. The pH level of the seawater was maintained at 6.3 by the acids addition. Heat exchange monitoring equipment and channels exposing different metal specimens were installed on each of the lines. Observation by microscope and EDS analyses were carried out both on the specimen surfaces and on the cross section of the fouling after fracturing in liquid N{sub 2}. The results obtained show that: fouling must not be confused with its effects or simply with its biological components; acidifying seawater can prevent the resistance to heat exchange from increasing without impeding its biological activity. Observation by microscope of the fouling cross sections showed that in untreated seawater the foulings on stainless steel were composed of a continuous compact layer, covered by disorderly clusters. These compact layers were found to contain high quantities of corrosion products of the metals. Elements typical of corrosion products of ferrous materials (Fe, Mn) were also found on Pt, copper alloys and plastic materials. The addition of HCl or H{sub 2}SO{sub 4} to the seawater, to bring it to pH 6.3, reduces the amount of fouling adhering to the surfaces, prevents the development of the continuous layer containing iron and prevents significant increases in heat exchange resistance. The addition of CO{sub 2} can encourage the development of incoherent fibrous material with high Si content and low Fe content which is of little impediment to heat exchange. The addition of lactic acid can encourage both the abnormal development of biomass and the formation of several, separate, layers on stainless steel surfaces.

  17. Generation of acids from mine waste: Oxidative leaching of pyrrhotite in dilute H{sub 2}SO{sub 4} solutions at pH 3.0

    SciTech Connect

    Pratt, A.R.; Nesbitt, H.W.; Muir, I.J.

    1994-12-01

    Pyrrhotite (Fe{sub 7}S{sub 8}) grains 3 x 3 x 6 mm were reacted in solutions of H{sub 2}SO{sub 4} (pH 3.0) for eight hours and analyzed using secondary electron microscopy (SEM), Auger electron spectroscopy (AES), and X-ray photoelectron spectroscopy (XPS). SEM images of reacted surfaces display an array of reaction textures, which are interpreted to represent a five-stage paragenetic alteration sequence. Leached pyrrhotite surfaces are initially featureless. Surfaces leached more extensively develop a mottled felty texture. Subsequent drying of reacted surfaces causes dehydration, producing cracked, tiled surfaces. Prolonged drying intensifies the effects of desiccation, producing rubbly textures. The rubble is readily spalled, exposing smooth underlayers. AES and XPS data collected from textured surfaces indicate primarily Fe-oxyhydroxide reaction products. AES depth profiles show that S varies antipathetically with oxygen. AES analysis of T5 textured surfaces (underlayer exposed by spalling) detect only Fe and S, with S significantly enriched over Fe. XPS and modelled AES data show T5 textured regions are mainly ferric iron bonded to disulphide and/or polysulphide species. The accumulation of S in the underlayer is accomplished by preferential migration of Fe to the overlying oxyhydroxide layer to the pyrrhotite surface, thus, promoting spallation. Spalling of Fe(III)-oxyhydroxides is promoted in waste rock dumps and tailings situated above the water table by periodic wetting, drying, and desiccation of the oxyhydroxide layer. These circumstances may, in turn, lead to high concentrations of suspended Fe-oxyhydroxide in tailings ponds during flooding and in ponds where there are dramatic seasonal overturns of lake or pond water. Exposure by spalling of S-rich sublayers to aqueous solutions is an effective means for producing sulphuric acid-rich mine waste runoff, and of producing periodic flushes of sulphuric acid-rich drainage waters.

  18. High temperature corrosion studies. A. Iron: based superalloy in SO/sub 2//O/sub 2/ atmospheres. B. Gas: solid reaction with formation of volatile species

    SciTech Connect

    Liu, T.K.

    1980-03-01

    The thermogravimetric method was used to study high temperature corrosion under SO/sub 2//O/sub 2/ atmosphere applied to Armco 18SR alloys with different heat treatment histories, Armco T310 and pure chromium between 750 and 1100/sup 0/C. The weight gain follows the parabolic rate law. The volatilization of the protective Cr/sub 2/O/sub 3/ layer via formation of CrO/sub 3/ was taken into account above 900/sup 0/C for long time runs. The parabolic rate and the volatilization rate, derived from fitting the experimental data to the modified Tedmon's non-linear model, were correlated using the Arrhenius equation. Armco 18SR-C has the best corrosion resistance of the Armco 18SR alloys. Armco T310 is not protective at high temperatures. The available rate data on the oxidation of chromium oxide, chlorination of chromium, oxidation-chlorination of chromium oxide, chlorination of nickel and chlorination of iron were found to be predictable. The calculation of high temperature volatilization rate was performed using the available fluid correlation equations and the Lennard-Jones parameters derived from the molecule with similar structure and from the low temperature viscosity measurement. The lower predicted volatilization rate is due to the use of the Chapman-Enskog equation with the Lennard-Jones parameters mostly derived from the low temperature viscosity measurement. This was substantiated by comparing the reliable high temperature diffusion rate in the literature with the above mentioned calculational method. The experimental volatilization rates of this study are compared with the other related studies and the mass transfer predictions.

  19. Aerodynamical sealing by air curtains

    NASA Astrophysics Data System (ADS)

    Frank, Daria; Linden, Paul

    2015-11-01

    Air curtains are artificial high-velocity plane turbulent jets which are installed in a doorway in order to reduce the heat and the mass exchange between two environments. The performance of an air curtain is assessed in terms of the sealing effectiveness E, the fraction of the exchange flow prevented by the air curtain compared to the open-door situation. The main controlling parameter for air curtain dynamics is the deflection modulus Dm representing the ratio of the momentum flux of the air curtain and the transverse forces acting on it due to the stack effect. In this talk, we examine the influence of two factors on the performance of an air curtain: the presence of an additional ventilation pathway in the room, such as a small top opening, and the effects of an opposing buoyancy force which for example arises if a downwards blowing air curtain is heated. Small-scale experiments were conducted to investigate the E (Dm) -curve of an air curtain in both situations. We present both experimental results and theoretical explanations for our observations. We also briefly illustrate how simplified models developed for air curtains can be used for more complex phenomena such as the effects of wind blowing around a model building on the ventilation rates through the openings.

  20. Synthesis and characterization of 2-phosphonoethanesulfonic acid and a barium-hydrogenphosphonatoethanesulfonate - BaH(O{sub 3}P-C{sub 2}H{sub 4}-SO{sub 3})

    SciTech Connect

    Sonnauer, Andreas

    2008-03-15

    Following the strategy of using polyfunctional phosphonic acids for the synthesis of new metal phosphonates, the organic linker molecule 2-phosphonoethanesulfonic acid, H{sub 2}O{sub 3}P-C{sub 2}H{sub 4}-SO{sub 3}H (1) (H{sub 3}L), was synthesized and characterized in detail. The acid was used in a high-throughput (HT) investigation of the system BaCl{sub 2}/H{sub 3}L/NaOH/H{sub 2}O. The HT experiments comprising 48 individual hydrothermal reactions were performed to systematically investigate the influence of pH of the starting mixture as well as the molar ratio Ba{sup 2+}: H{sub 3}L. Only two reaction products were observed: small amounts of BaCO{sub 3} under basic conditions and BaH(O{sub 3}P-C{sub 2}H{sub 4}-SO{sub 3}) (2). For compounds 1 and 2 the crystal structures were determined from single-crystal X-ray diffraction data (H{sub 2}O{sub 3}P-C{sub 2}H{sub 4}-SO{sub 3}H: trigonal, P3{sub 2}, a=814.58(1), c=861.20(2) pm, Z=3, R1=0.0254, wR{sub 2}=0.0758 for I>2{sigma}(I); BaH(O{sub 3}P-C{sub 2}H{sub 4}-SO{sub 3}): orthorhombic, Ibam, a=953.39(19), b=855.55(17), c=867.82(17) pm, Z=4, R1=0.0162, wR{sub 2}=0.0417 for I>2{sigma}(I)). The structure of H{sub 3}L (1) is stabilized exclusively by strong hydrogen bonds. Compound 2 is built up by chains of edge sharing BaO{sub 8} polyhedra. These chains are connected to a three-dimensional network by the -CH{sub 2}CH{sub 2}- linker of the ligand. Thermogravimetric investigation of compound 2, as well as IR spectra of 1 and 2 are presented. - Graphical abstract: The synthesis of the ligand H{sub 2}O{sub 3}P-C{sub 2}H{sub 4}-SO{sub 3}H and its use in the systematic investigation in the system BaCl{sub 2}/H{sub 2}O{sub 3}P-C{sub 2}H{sub 4}-SO{sub 3}H/NaOH/H{sub 2}O led to the new barium phosphonatosulfonate BaH(O{sub 3}P-C{sub 2}H{sub 4}-SO{sub 3}H)

  1. Electrophilic addition of astatine

    SciTech Connect

    Norseev, Yu.V.; Vasaros, L.; Nhan, D.D.; Huan, N.K.

    1988-03-01

    It has been shown for the first time that astatine is capable of undergoing addition reactions to unsaturated hydrocarbons. A new compound of astatine, viz., ethylene astatohydrin, has been obtained, and its retention numbers of squalane, Apiezon, and tricresyl phosphate have been found. The influence of various factors on the formation of ethylene astatohydrin has been studied. It has been concluded on the basis of the results obtained that the univalent cations of astatine in an acidic medium is protonated hypoastatous acid.

  2. Natural Flow Air Cooled Photovoltaics

    NASA Astrophysics Data System (ADS)

    Tanagnostopoulos, Y.; Themelis, P.

    2010-01-01

    Our experimental study aims to investigate the improvement in the electrical performance of a photovoltaic installation on buildings through cooling of the photovoltaic panels with natural air flow. Our experimental study aims to investigate the improvement in the electrical performance of a photovoltaic installation on buildings through cooling of the photovoltaic panels with natural air flow. We performed experiments using a prototype based on three silicon photovoltaic modules placed in series to simulate a typical sloping building roof with photovoltaic installation. In this system the air flows through a channel on the rear side of PV panels. The potential for increasing the heat exchange from the photovoltaic panel to the circulating air by the addition of a thin metal sheet (TMS) in the middle of air channel or metal fins (FIN) along the air duct was examined. The operation of the device was studied with the air duct closed tightly to avoid air circulation (CLOSED) and the air duct open (REF), with the thin metal sheet (TMS) and with metal fins (FIN). In each case the experiments were performed under sunlight and the operating parameters of the experimental device determining the electrical and thermal performance of the system were observed and recorded during a whole day and for several days. We collected the data and form PV panels from the comparative diagrams of the experimental results regarding the temperature of solar cells, the electrical efficiency of the installation, the temperature of the back wall of the air duct and the temperature difference in the entrance and exit of the air duct. The comparative results from the measurements determine the improvement in electrical performance of the photovoltaic cells because of the reduction of their temperature, which is achieved by the naturally circulating air.

  3. 14 CFR 399.33 - Additional fare flexibility.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Additional fare flexibility. 399.33 Section... Additional fare flexibility. For scheduled service in the areas set forth in § 399.32(a), certificated air carriers have the following fare flexibility in addition to that set forth in § 399.32: (a) First...

  4. 14 CFR 399.33 - Additional fare flexibility.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Additional fare flexibility. 399.33 Section... Additional fare flexibility. For scheduled service in the areas set forth in § 399.32(a), certificated air carriers have the following fare flexibility in addition to that set forth in § 399.32: (a) First...

  5. 14 CFR 399.33 - Additional fare flexibility.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Additional fare flexibility. 399.33 Section... Additional fare flexibility. For scheduled service in the areas set forth in § 399.32(a), certificated air carriers have the following fare flexibility in addition to that set forth in § 399.32: (a) First...

  6. 14 CFR 399.33 - Additional fare flexibility.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Additional fare flexibility. 399.33 Section... Additional fare flexibility. For scheduled service in the areas set forth in § 399.32(a), certificated air carriers have the following fare flexibility in addition to that set forth in § 399.32: (a) First...

  7. 14 CFR 399.33 - Additional fare flexibility.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Additional fare flexibility. 399.33 Section... Additional fare flexibility. For scheduled service in the areas set forth in § 399.32(a), certificated air carriers have the following fare flexibility in addition to that set forth in § 399.32: (a) First...

  8. Functional Generalized Additive Models.

    PubMed

    McLean, Mathew W; Hooker, Giles; Staicu, Ana-Maria; Scheipl, Fabian; Ruppert, David

    2014-01-01

    We introduce the functional generalized additive model (FGAM), a novel regression model for association studies between a scalar response and a functional predictor. We model the link-transformed mean response as the integral with respect to t of F{X(t), t} where F(·,·) is an unknown regression function and X(t) is a functional covariate. Rather than having an additive model in a finite number of principal components as in Müller and Yao (2008), our model incorporates the functional predictor directly and thus our model can be viewed as the natural functional extension of generalized additive models. We estimate F(·,·) using tensor-product B-splines with roughness penalties. A pointwise quantile transformation of the functional predictor is also considered to ensure each tensor-product B-spline has observed data on its support. The methods are evaluated using simulated data and their predictive performance is compared with other competing scalar-on-function regression alternatives. We illustrate the usefulness of our approach through an application to brain tractography, where X(t) is a signal from diffusion tensor imaging at position, t, along a tract in the brain. In one example, the response is disease-status (case or control) and in a second example, it is the score on a cognitive test. R code for performing the simulations and fitting the FGAM can be found in supplemental materials available online.

  9. View of southwest corner showing ell addition and carport, facing ...

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

    View of southwest corner showing ell addition and carport, facing northeast. - Albrook Air Force Station, Field Officer's Quarters, West side of Dargue Avenue Circle, Balboa, Former Panama Canal Zone, CZ

  10. 3. Northwest side and southwest rear of addition. View to ...

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

    3. Northwest side and southwest rear of addition. View to east. - Offutt Air Force Base, Looking Glass Airborne Command Post, Aerospace Ground Equipment (AGE) Storage Facility, Far Northwest end of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  11. 5. General interior overview of addition. View to south. ...

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

    5. General interior overview of addition. View to south. - Offutt Air Force Base, Looking Glass Airborne Command Post, Aerospace Ground Equipment (AGE) Storage Facility, Far Northwest end of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  12. 2. Southeast side of addition. View to northwest. Offutt ...

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

    2. Southeast side of addition. View to northwest. - Offutt Air Force Base, Looking Glass Airborne Command Post, Aerospace Ground Equipment (AGE) Storage Facility, Far Northwest end of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  13. 6. General interior overview of addition. View to northwest. ...

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

    6. General interior overview of addition. View to northwest. - Offutt Air Force Base, Looking Glass Airborne Command Post, Aerospace Ground Equipment (AGE) Storage Facility, Far Northwest end of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  14. Interior view of addition pharmacy showing dutch door and security ...

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

    Interior view of addition pharmacy showing dutch door and security ceiling grate, facing north. - Albrook Air Force Station, Dispensary, East side of Canfield Avenue, Balboa, Former Panama Canal Zone, CZ

  15. View looking west down northeast side of building. Small additions ...

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

    View looking west down northeast side of building. Small additions and control tower visible. - Naval Air Station North Island, Seaplane Hangars, Roe Street, North Island, San Diego, San Diego County, CA

  16. Air pollution.

    PubMed

    Le, Nhu D; Sun, Li; Zidek, James V

    2010-01-01

    Toxic air pollutants are continuously released into the air supply. Various pollutants come from chemical facilities and small businesses, such as automobile service stations and dry cleaning establishments. Others, such as nitrogen oxides, carbon monoxide and other volatile organic chemicals, arise primarily from the incomplete combustion of fossil fuels (coal and petroleum) and are emitted from sources that include car exhausts, home heating and industrial power plants. Pollutants in the atmosphere also result from photochemical transformations; for example, ozone is formed when molecular oxygen or nitrogen interacts with ultraviolet radiation. An association between air pollution exposure and lung cancer has been observed in several studies. The evidence for other cancers is far less conclusive. Estimates of the population attributable risk of cancer has varied substantially over the last 40 years, reflecting the limitations of studies; these include insufficient information on confounders, difficulties in characterizing associations due to a likely lengthy latency interval, and exposure misclassification. Although earlier estimates were less than one percent, recent cohort studies that have taken into account some confounding factors, such as smoking and education amongst others, suggest that approximately 3.6% of lung cancer in the European Union could be due to air pollution exposure, particularly to sulphate and fine particulates. A separate cohort study estimated 5-7% of lung cancers in European never smokers and ex-smokers could be due to air pollution exposure. Therefore, while cigarette smoking remains the predominant risk factor, the proportion of lung cancers attributable to air pollution may be higher than previously thought. Overall, major weaknesses in all air-pollution-and-cancer studies to date have been inadequate characterization of long-term air pollution exposure and imprecise or no measurements of covariates. It has only been in the last

  17. Siloxane containing addition polyimides

    NASA Technical Reports Server (NTRS)

    Maudgal, S.; St. Clair, T. L.

    1984-01-01

    Addition polyimide oligomers have been synthesized from bis(gamma-aminopropyl) tetramethyldisiloxane and 3, 3', 4, 4'-benzophenonetetracarboxylic dianhydride using a variety of latent crosslinking groups as endcappers. The prepolymers were isolated and characterized for solubility (in amide, chlorinated and ether solvents), melt flow and cure properties. The most promising systems, maleimide and acetylene terminated prepolymers, were selected for detailed study. Graphite cloth reinforced composites were prepared and properties compared with those of graphite/Kerimid 601, a commercially available bismaleimide. Mixtures of the maleimide terminated system with Kerimid 601, in varying proportions, were also studied.

  18. Addition polyimide adhesives containing various end groups

    NASA Technical Reports Server (NTRS)

    Saint Clair, A. K.; Saint Clair, T. L.

    1982-01-01

    Addition polyimode oligomers have been synthesized from 3,3 prime, 4,4 prime-benzophenone tetracarboxylic acid dianhydride and 3,3 prime-methylenedianiline using a variety of latent crosslinking groups as end-caps. The nominal 1300 molecular weight imide prepolymers were isolated and characterized for solubility in amide, chlorinated and ether solvents, melt-flow and cure properties, glass transition temperature, and thermal stability on heating in an air atmosphere. Adhesive strengths of the polyimides were obtained both at ambient and elevated temperatures before and after aging at 232 C. Properties of the novel addition polyimides were compared to a known nadic end-capped adhesive, LARC-13.

  19. Platelet additive solution - electrolytes.

    PubMed

    Azuma, Hiroshi; Hirayama, Junichi; Akino, Mitsuaki; Ikeda, Hisami

    2011-06-01

    Recent attention to solutions that replace most or all plasma in platelet concentrates, while maintaining satisfactory platelet function, is motivated by the potential of plasma reduction or depletion to mitigate various transfusion-related adverse events. This report considers the electrolytic composition of previously described platelet additive solutions, in order to draw general conclusions about what is required for platelet function and longevity. The optimal concentrations of Na(+) and Cl(-) are 69-115 mM. The presence of both K(+) and Mg(2+) in platelet suspension at nearly physiological concentrations (3-5mM and 1.5-3mM, respectively) is indispensable for good preservation capacity because both electrolytes are required to prevent platelet activation. In contrast to K(+) and Mg(2+), Ca(2+) may not be important because no free Ca(2+) is available in M-sol, which showed excellent platelet preservation capacity at less than 5% plasma concentration. The importance of bicarbonate (approximately 40 mM) can be recognized when the platelets are suspended in additive solution under less than 5% residual plasma concentration.

  20. (Draft) Community air pollution and mortality: Analysis of 1980 data from US metropolitan areas

    SciTech Connect

    Lipfert, F.W.

    1992-11-01

    1980 data from up to 149 metropolitan areas were used to define cross-sectional associations between community air pollution and excess'' human mortality. The regression model proposed by Ozkaynak and Thurston (1987), which accounted for age, race, education, poverty, and population density, was evaluated and several new models were developed. The new models also accounted for migration, drinking water hardness, and smoking, and included a more detailed description of race. Cause-of-death categories analyzed include all causes, all non-external'' causes, major cardiovascular diseases, and chronic obstructive pulmonary diseases (COPD). Both annual mortality rates and their logarithms were analyzed. Air quality data were obtained from the EPA AIRS database (TSP, SO[sub 4][sup =], Mn, and ozone) and from the inhalable particulate network (PM[sub 15], PM[sub 2.5] and SO[sub 4][sup =], for 63[sup 4] locations). The data on particulates were averaged across all monitoring stations available for each SMSA and the TSP data were restricted to the year 1980. The associations between mortality and air pollution were found to be dependent on the socioeconomic factors included in the models, the specific locations included in the data set, and the type of statistical model used. Statistically significant associations were found as follows: between TSP and mortality due to non-external causes with log-linear models, but not with a linear model betweenestimated 10-year average (1980--90) ozone levels and 1980 non-external and cardiovascular deaths; and between TSP and COPD mortality for both linear and log-linear models. When the sulfate contribution to TSP was subtracted, the relationship with COPD mortality was strengthened.

  1. (Draft) Community air pollution and mortality: Analysis of 1980 data from US metropolitan areas

    SciTech Connect

    Lipfert, F.W.

    1992-11-01

    1980 data from up to 149 metropolitan areas were used to define cross-sectional associations between community air pollution and ``excess`` human mortality. The regression model proposed by Ozkaynak and Thurston (1987), which accounted for age, race, education, poverty, and population density, was evaluated and several new models were developed. The new models also accounted for migration, drinking water hardness, and smoking, and included a more detailed description of race. Cause-of-death categories analyzed include all causes, all ``non-external`` causes, major cardiovascular diseases, and chronic obstructive pulmonary diseases (COPD). Both annual mortality rates and their logarithms were analyzed. Air quality data were obtained from the EPA AIRS database (TSP, SO{sub 4}{sup =}, Mn, and ozone) and from the inhalable particulate network (PM{sub 15}, PM{sub 2.5} and SO{sub 4}{sup =}, for 63{sup 4} locations). The data on particulates were averaged across all monitoring stations available for each SMSA and the TSP data were restricted to the year 1980. The associations between mortality and air pollution were found to be dependent on the socioeconomic factors included in the models, the specific locations included in the data set, and the type of statistical model used. Statistically significant associations were found as follows: between TSP and mortality due to non-external causes with log-linear models, but not with a linear model betweenestimated 10-year average (1980--90) ozone levels and 1980 non-external and cardiovascular deaths; and between TSP and COPD mortality for both linear and log-linear models. When the sulfate contribution to TSP was subtracted, the relationship with COPD mortality was strengthened.

  2. Air weapon fatalities.

    PubMed Central

    Milroy, C M; Clark, J C; Carter, N; Rutty, G; Rooney, N

    1998-01-01

    AIMS: To describe characteristics of a series of people accidentally and deliberately killed by air powered weapons. METHODS: Five cases of fatal airgun injury were identified by forensic pathologists and histopathologists. The circumstances surrounding the case, radiological examination, and pathological findings are described. The weapon characteristics are also reported. RESULTS: Three of the victims were adult men, one was a 16 year old boy, and one an eight year old child. Four of the airguns were .22 air rifles, the other a .177 air rifle. Two committed suicide, one person shooting himself in the head, the other in the chest. In both cases the guns were fired at contact range. Three of the cases were classified as accidents: in two the pellet penetrated into the head and in one the chest. CONCLUSIONS: One person each year dies from an air powered weapon injury in the United Kingdom. In addition there is considerable morbidity from airgun injuries. Fatalities and injuries are most commonly accidents, but deliberately inflicted injuries occur. Airguns are dangerous weapons when inappropriately handled and should not be considered as toys. Children should not play with airguns unsupervised. Images PMID:9797730

  3. Additive composition, for gasoline

    SciTech Connect

    Vataru, M.

    1989-01-10

    An admixture is described that comprises Diesel fuel and an additive composition added thereto which is between about 0.05 to about 2.0 percent by weight of the fuel, the composition comprising: (a) between about 0.05 and 25% relative weight parts of an organic peroxide, and (b) between about 0.1 and 25% relative weight parts of detergent selected from the component group that consists of: (i) fatty amines; (ii) ethoxylated and propoxylated derivatives of fatty amines; (iii) fatty diamines; (iv) fatty imidazlines; (v) polymeric amines and derivatives thereof; (vi) combination of one or more of the (i) through (v) components with carboxylic acid or acids having from three to forth carbon atoms, (c) from about 99.0 to about 50% by weight of a hydrocarbon solvent.

  4. Teardrop bladder: additional considerations

    SciTech Connect

    Wechsler, R.J.; Brennan, R.E.

    1982-07-01

    Nine cases of teardrop bladder (TDB) seen at excretory urography are presented. In some of these patients, the iliopsoas muscles were at the upper limit of normal in size, and additional evaluation of the perivesical structures with computed tomography (CT) was necessary. CT demonstrated only hypertrophied muscles with or without perivesical fat. The psoas muscles and pelvic width were measured in 8 patients and compared with the measurements of a control group of males without TDB. Patients with TDB had large iliopsoas muscles and narrow pelves compared with the control group. The psoas muscle width/pelvic width ratio was significantly greater (p < 0.0005) in patients with TDB than in the control group, with values of 1.04 + 0.05 and 0.82 + 0.09, respectively. It is concluded that TDB is not an uncommon normal variant in black males. Both iliopsoas muscle hypertrophy and a narrow pelvis are factors that predispose a patient to TDB.

  5. New addition curing polyimides

    NASA Technical Reports Server (NTRS)

    Frimer, Aryeh A.; Cavano, Paul

    1991-01-01

    In an attempt to improve the thermal-oxidative stability (TOS) of PMR-type polymers, the use of 1,4-phenylenebis (phenylmaleic anhydride) PPMA, was evaluated. Two series of nadic end-capped addition curing polyimides were prepared by imidizing PPMA with either 4,4'-methylene dianiline or p-phenylenediamine. The first resulted in improved solubility and increased resin flow while the latter yielded a compression molded neat resin sample with a T(sub g) of 408 C, close to 70 C higher than PME-15. The performance of these materials in long term weight loss studies was below that of PMR-15, independent of post-cure conditions. These results can be rationalized in terms of the thermal lability of the pendant phenyl groups and the incomplete imidization of the sterically congested PPMA. The preparation of model compounds as well as future research directions are discussed.

  6. Perspectives on Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Bourell, David L.

    2016-07-01

    Additive manufacturing (AM) has skyrocketed in visibility commercially and in the public sector. This article describes the development of this field from early layered manufacturing approaches of photosculpture, topography, and material deposition. Certain precursors to modern AM processes are also briefly described. The growth of the field over the last 30 years is presented. Included is the standard delineation of AM technologies into seven broad categories. The economics of AM part generation is considered, and the impacts of the economics on application sectors are described. On the basis of current trends, the future outlook will include a convergence of AM fabricators, mass-produced AM fabricators, enabling of topology optimization designs, and specialization in the AM legal arena. Long-term developments with huge impact are organ printing and volume-based printing.

  7. Sewage sludge additive

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Mueller, W. A.; Ingham, J. D. (Inventor)

    1980-01-01

    The additive is for a raw sewage treatment process of the type where settling tanks are used for the purpose of permitting the suspended matter in the raw sewage to be settled as well as to permit adsorption of the dissolved contaminants in the water of the sewage. The sludge, which settles down to the bottom of the settling tank is extracted, pyrolyzed and activated to form activated carbon and ash which is mixed with the sewage prior to its introduction into the settling tank. The sludge does not provide all of the activated carbon and ash required for adequate treatment of the raw sewage. It is necessary to add carbon to the process and instead of expensive commercial carbon, coal is used to provide the carbon supplement.

  8. Parent's Guide to School Indoor Air Quality. Revised

    ERIC Educational Resources Information Center

    Healthy Schools Network, Inc., 2012

    2012-01-01

    Air pollution is air pollution, indoors or out. Good indoor air quality (IAQ) contributes to a favorable learning environment for students, protects health, and supports the productivity of school personnel. In schools in poor repair, leaky roofs and crumbling walls have caused additional indoor air quality problems, including contamination with…

  9. Air Quality System (AQS)

    EPA Pesticide Factsheets

    The Air Quality System (AQS) database contains measurements of air pollutant concentrations from throughout the United States and its territories. The measurements include both criteria air pollutants and hazardous air pollutants.

  10. Novel technologies for SO{sub x}/NO{sub x} removal from flue gas. Technical report, March 1, 1994--May 31, 1994

    SciTech Connect

    Kung, H.; Kung, M.; Yang, B.; Spivey, J.J.; Jang, B.W.

    1994-09-01

    The goal of this project is to develop a cost-effective low temperature deNO{sub x} catalyst to be used in the Research Triangle Institute-Waterloo SO{sub 2}/NO{sub x} process for boiler retrofit applications. The performance goal of the catalyst is to convert over 80% of the NO in the flue gas at a temperature as low as 150{degrees}C in the presence of 4% O{sub 2}, and 10% water. Based on the results obtained in the previous quarter, which showed a La-Cu-ZrO{sub 2} catalyst to be a promising low temperature catalyst in the presence of 2% H{sub 2}O in the reduction of NO to N{sub 2} with isobutanol, research was conducted to investigate the variations in feed conditions on the performance of the catalyst. Specifically, the effect of increased H{sub 2}O concentration and the effect of NO{sub 2} in the feed were investigated. Although the activity of the catalyst declined when the H{sub 2}O concentration was increased from 2 to 10%, the decline was relatively mild compared with that when the water content was changed from 0 to 2%. The effect of NO{sub 2} was investigated because oxidation of NO to NO{sub 2}, a thermodynamically favorable process, proceeds at a finite rate even in the absence of a catalyst. It was found that, under the low temperature reaction conditions, replacement of NO{sub 2} with NO did not affect the catalytic performance of the La-Cu-ZrO{sub 2} catalyst. Besides studying the La-Cu-ZrO{sub 2} catalyst, effort has continued in screening other potential catalysts. A promising 5%Cu-2%Ag catalyst supported on active carbon was found that catalyzes NO reduction by acetone. At 150{degrees}C, 35% NO conversion was obtained in the presence of 4% O{sub 2} and 8% H{sub 2}O at a space velocity of 3000 h{sup {minus}1} after 5 h on stream.

  11. Novel technologies for SO{sub x}/NO{sub x} removal from flue gas. [Quarterly] technical report, December 1, 1993--February 28, 1994

    SciTech Connect

    Kung, H.; Kung, M.; Yang, B.; Spivey, J.J.; Jang, B.W.

    1994-06-01

    The goal of this project is to develop a cost-effective low temperature deNO{sub x} catalyst to be used in the Research Triangle Institute-Waterloo SO{sub x}/NO{sub x} process for boiler retrofit applications. The performance goal of the catalyst is to convert over 80% of the NO in the flue gas at a temperature as low as 150{degree}C in the presence of 4% O{sub 2} and 10% water. Based on the results obtained in the first quarter, which showed that modification of a Cu-ZrO{sub 2} catalyst with Nd increased the conversion of NO to N{sub 2}, especially at higher partial pressures of oxygen, and that ethanol was a more effective reductant than propene in the presence of water vapor, research was conducted in this quarter to investigate the use of other modifiers and other alcohols as reductants. It was found that modification of Cu-ZrO{sub 2} by La was more effective than by Nd or Gd. It decreased the hydrocarbon combustion activity of the catalyst while increasing the NO conversion. A Cu-Ga{sub 2}O{sub 3} catalyst was also tested. It was superior to Cu-ZrO{sub 2} at temperatures higher than 250{degree}C, but inferior at lower temperatures. On the La-Cu-ZrO{sub 2} catalyst, isobutanol was a very effective reductant for NO, being more effective than ethanol. In the presence of 4% O{sub 2}, 2% water, and with a space velocity of 3000 h{sup {minus}1}, an NO conversion to N{sub 2} of 83% was obtained using 1200 ppM isobutanol at 200{degree}C. This is believed to be the highest conversion reported to data without using NH{sub 3} as the reductant. Other catalysts not containing copper were also tested, but their performance was inferior to this La-Cu-ZrO{sub 2} catalyst.

  12. Additive lattice kirigami.

    PubMed

    Castle, Toen; Sussman, Daniel M; Tanis, Michael; Kamien, Randall D

    2016-09-01

    Kirigami uses bending, folding, cutting, and pasting to create complex three-dimensional (3D) structures from a flat sheet. In the case of lattice kirigami, this cutting and rejoining introduces defects into an underlying 2D lattice in the form of points of nonzero Gaussian curvature. A set of simple rules was previously used to generate a wide variety of stepped structures; we now pare back these rules to their minimum. This allows us to describe a set of techniques that unify a wide variety of cut-and-paste actions under the rubric of lattice kirigami, including adding new material and rejoining material across arbitrary cuts in the sheet. We also explore the use of more complex lattices and the different structures that consequently arise. Regardless of the choice of lattice, creating complex structures may require multiple overlapping kirigami cuts, where subsequent cuts are not performed on a locally flat lattice. Our additive kirigami method describes such cuts, providing a simple methodology and a set of techniques to build a huge variety of complex 3D shapes.

  13. Ceramics with Different Additives

    NASA Astrophysics Data System (ADS)

    Wang, Juanjuan; Feng, Lajun; Lei, Ali; Zhao, Kang; Yan, Aijun

    2014-09-01

    Li2CO3, MgCO3, BaCO3, and Bi2O3 dopants were introduced into CaCu3Ti4O12 (CCTO) ceramics in order to improve the dielectric properties. The CCTO ceramics were prepared by conventional solid-state reaction method. The phase structure, microstructure, and dielectric behavior were carefully investigated. The pure structure without any impurity phases can be confirmed by the x-ray diffraction patterns. Scanning Electron Microscopy (SEM) analysis illuminated that the grains of Ca0.90Li0.20Cu3Ti4O12 ceramics were greater than that of pure CCTO. It was important for the properties of the CCTO ceramics to study the additives in complex impedance spectroscopy. It was found that the Ca0.90Li0.20Cu3Ti4O12 ceramics had the higher permittivity (>45000), the lower dielectric loss (<0.025) than those of CCTO at 1 kHz at room temperature and good temperature stability from -30 to 75 °C.

  14. Additive lattice kirigami

    PubMed Central

    Castle, Toen; Sussman, Daniel M.; Tanis, Michael; Kamien, Randall D.

    2016-01-01

    Kirigami uses bending, folding, cutting, and pasting to create complex three-dimensional (3D) structures from a flat sheet. In the case of lattice kirigami, this cutting and rejoining introduces defects into an underlying 2D lattice in the form of points of nonzero Gaussian curvature. A set of simple rules was previously used to generate a wide variety of stepped structures; we now pare back these rules to their minimum. This allows us to describe a set of techniques that unify a wide variety of cut-and-paste actions under the rubric of lattice kirigami, including adding new material and rejoining material across arbitrary cuts in the sheet. We also explore the use of more complex lattices and the different structures that consequently arise. Regardless of the choice of lattice, creating complex structures may require multiple overlapping kirigami cuts, where subsequent cuts are not performed on a locally flat lattice. Our additive kirigami method describes such cuts, providing a simple methodology and a set of techniques to build a huge variety of complex 3D shapes. PMID:27679822

  15. A chemical model for the major electrolyte components of the Hanford waste tanks. The binary electrolytes in the system: Na-NO{sub 3}-NO{sub 2}-SO{sub 4}-CO{sub 3}-F-PO{sub 4}-OH-AI(OH){sub 4}-H{sub 2}O

    SciTech Connect

    Felmy, A.R.; Rustad, J.R.; Mason, M.J.; Bretonne, R. de la

    1994-08-01

    An aqueous thermodynamic model is developed, based on the equations of Pitzer, which accurately model the major binary electrolytes in the Na-NO{sub 3}-NO{sub 2}-SO{sub 4}-CO{sub 3}-F-PO{sub 4}-OH-Al(OH){sub 4}-H{sub 2}O chemical system. This model was developed both from existing data in the literature, and from new osmotic and solubility measurements made as part of this study. Some of the new experimental data developed as part of this study include measurements of osmotic coefficients for NaNO{sub 3}, NaNO{sub 2}, and Na{sub 3}PO{sub 4} at both 50 and 100{degrees}C as well as selected measurements of NaF at 100{degrees}C. In addition, the solubility of gibbsite was measured in mixed NaOH-NaNO{sub 3} solutions to determine the reliability of existing thermodynamic models of aluminum hydroxide solubility when applied to concentrated nitrate. In general the final model proposed here is valid from dilute solution to salt saturation over the temperature range 25-100{degrees}C. The accuracy of the model is tested by comparisons of the model predictions with experimental data in selected common-ion ternary systems. When necessary a few commonion ternary ion interaction parameters for the Pitzer model were developed.

  16. Polarized experimental and theoretical K-edge x-ray absorption studies of SO/sub 4//sup 2-/, ClO/sub 3//sup -/, S/sub 2/O/sub 3//sup 2-/, and S/sub 2/O/sub 6//sup 2-/

    SciTech Connect

    Tyson, T.A.; Roe, A.L.; Frank, P.; Hodgson, K.O.; Hedman, B.

    1989-04-01

    The first studies of the polarized sulfur and chlorine x-ray K-edge absorption spectra of the oxyanions SO/sub 4//sup 2-/ (sulfate), ClO/sub 3//sup -/ (chlorate), S/sub 2/O/sub 3//sup 2-/ (thiosulfate), and S/sub 2/O/sub 6//sup 2-/ (dithionate) are presented. To provide a basis for the interpretation of the experimental measurements, extended continuum multiple-scattering X..cap alpha.. computations were carried out. This approach enabled us to identify features in the absorption spectra both by symmetry and final-state type (final bound states or final continuum states). For the thiosulfate anion (which has two nonequivalent sulfur atoms) it proved possible to determine which sulfur atom is responsible for each of a series of well-resolved features in the polarized spectra. In addition, generalizing from the case of the chlorate anion, molecules in which the absorbing atom is not completely surrounded by ligands (''open clusters'') may have important contributions from the second shell of neighbors manifested as features in the continuum region of the spectrum.

  17. Thermoluminescence response of K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3} nanophosphor Co-doped with Eu and Ce for gamma ray dosimetry

    SciTech Connect

    Patil, B. J.; Bhadane, Mahesh S.; Dahiwale, S. S.; Bhoraskar, V. N.; Dhole, S. D.; Mandlik, N. T.; Kulkarni, M. S.; Bhatt, B. C.

    2015-06-24

    K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3} nanophosphors co-doped with Eu and Ce were synthesized by the chemical co-precipitation method. These samples were further annealed at 700 °C structural reformation. The structural and morphological characteristics were studied using XRD and TEM techniques. The particle size calculated from XRD spectra was around 35 nm. The as synthesized sample shows cubic structure annealed at 700 °C. The as synthesized and annealed sample of K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3}: EuCe were irradiated with Co{sup 60} gamma rays for the doses from 2Gy to 1kGy. The TL characteristic sample of co-doped were studied for the dosimetric application by gamma radiation. The TL spectrum of annealed sample has single peaked at 160 °C. The Eu doped sample has a high TL sensitivity than Ce doped sample. But after co-doping with Eu and Ce, TL intensity observed to be decreased. The decrees in TL peak intensity of the phosphor on co-doping of Eu and Ce gives an insight into the emission mechanism of the phosphor which involves energy transfer from Eu to Ce. The TL response of all the samples were found to be linear for the dose from 2 Gy to 1 KGy. Therefore, K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3}: EuCe nanophosphor can be used for the measurement of high dose of gamma radiation.

  18. Characterization and comparative study of coal combustion residues from a primary and additional flue gas secondary desulfurization process

    SciTech Connect

    Gomes, S.; Francois, M.; Evrard, O.; Pellissier, C.

    1998-11-01

    An extensive characterization and comparative study was done on two flue gas desulfurization (FGD) residues derived from the same coal. LR residues (originated from Loire/Rhone in the south of Lyon, France) are obtained after a primary desulfurization process (SO{sub 2} is trapped by reaction with CaO at a temperature of about 1100 C), and LM residues (originating from La Maxe, near Metz in the east of France) are obtained after an additional secondary desulfurization process (SO{sub 2} is removed further by reaction with Ca(OH){sub 2} at a temperature of about 120 C). Various and complementary investigation methods were used to determine their chemical, physical, and mineralogical properties: x-ray fluorescence and diffraction, scanning electron microscopy, differential scanning calorimetry, thermogravimetry analysis, granulometric distribution, pycnometric density, BET specific surface area and pH, conductivity measurements, and chemical analysis of their insoluble fraction. The FGD residues contain basically two main components: a silico-aluminous fly ash part and calcic FGD phases. In the LR residues the two components can be considered as independent, whereas they are linked in the LM residues because chemical reactions have occurred, leading to the formation of silico-calcic gel CSH, hydrated aluminate AFm, and AFt phases.

  19. Ambient air pollution exposure and the incidence of related health effects among racial/ethnic minorities

    SciTech Connect

    Nieves, L.A.; Wernette, D.R.

    1997-02-01

    Differences among racial and ethnic groups in morbidity and mortality rates for diseases, including diseases with environmental causes, have been extensively documented. However, documenting the linkages between environmental contaminants, individual exposures, and disease incidence has been hindered by difficulties in measuring exposure for the population in general and for minority populations in particular. After briefly discussing research findings on associations of common air pollutants with disease incidence, the authors summarize recent studies of radial/ethnic subgroup differences in incidence of these diseases in the US. They then present evidence of both historic and current patterns of disproportionate minority group exposure to air pollution as measured by residence in areas where ambient air quality standards are violated. The current indications of disproportionate potential exposures of minority and low-income populations to air pollutants represent the continuation of a historical trend. The evidence of linkage between disproportionate exposure to air pollution of racial/ethnic minorities and low-income groups and their higher rates of some air pollution-related diseases is largely circumstantial. Differences in disease incidence and mortality rates among racial/ethnic groups are discussed for respiratory diseases, cancers, and lead poisoning. Pollutants of concern include CO, Pb, SO{sub 2}, O{sub 3}, and particulates.

  20. Evaluation of a possible association of urban air toxics and asthma

    SciTech Connect

    Leikauf, G.D.; Kline, S.; Albert, R.E.; Baxter, C.S.

    1995-09-01

    The prevalence of asthma, measured either as the frequency of hospital admission or number of deaths attributed to asthma, has increased over the last 15 to 20 years. Rapid increases in disease prevalence are more likely to be attributable to environmental than genetic factors. inferring from past associations between air pollution and asthma, it is feasible that changes in the ambient environment could contribute to this increase in morbidity and mortality. Scientific evaluation of the links between air pollution and the exacerbation of asthma is incomplete, however. Currently, criteria pollutants [SO{sub x}NO{sub x}, O{sub 3}, CO, Pb, particulate matter (PM{sub 10})] and other risk factors (exposure to environmental tobacco smoke, volatile organic compounds, etc.) are constantly being evaluated as to their possible contributions to this situation. Data from these studies suggest that increases in respiratory disease are associated with exposures to ambient concentrations of particulate and gaseous pollutants. Similarly, exposure to environmental tobacco smoke, also a mixture of particles and gases and that current measurements of air pollution are, in part, indirect in that the concentrations of criteria pollutants are acting as surrogates of our exposure to a complex mixture. Other irritant air pollutants, including certain urban air toxics, are associated with asthma in occupational settings and may interact with criteria pollutants in ambient air to exacerbate asthma. 179 refs., 2 figs., 18 tabs.

  1. Air cell

    NASA Astrophysics Data System (ADS)

    Okamura, Okiyoshi; Wakasa, Masayuki; Tamanoi, Yoshihito

    1991-04-01

    The present invention relates to an air cell. This air cell provides a compact light-weight power source for model aircraft permitting them to fly for an extended period so that they may be used for such practical purposes as crop dusting, surveying, and photographing. The cell is comprised of a current collector so disposed between a magnesium, zinc, or aluminum alloy cathode and a petroleum graphite anode that it is in contact with the anode. The anode is formed by adding polytetrafluoroethylene dispersion liquid in a mixture of active carbon and graphite powder, pouring the mixture into a mold and heating it to form the anode. It is fabricated by a plurality of anode sections and is formed with at least one hole so that it can provide a cell which is compact in size and light in weight yet is capable of generating a high output. The anode, the cathode, and a separator are wetted by an electrolytic liquid. The electrolyte is continuously supplied through the life of the cell.

  2. The 1990 Clean Air Act and the implicit price of sulfur in coal - article no. 41

    SciTech Connect

    Lange, I.; Bellas, A.S.

    2007-07-01

    Prior to implementation of the 1990 Clean Air Act Amendments (CAAA), many estimates of the marginal cost of SO{sub 2} abatement were provided to guide policy makers. Numerous studies estimated the marginal cost of abatement to be between $250 and $760 per ton, though permits initially traded well below $200 and remained below $220 until 2004. We use a fixed effects estimator and a hedonic price model of coal purchases in order to determine the implicit price of sulfur. Data on contract coal purchases are divided into regulatory regimes based on when the contract was signed or re-negotiated. We find that purchases by Phase I plants made under contracts signed or re-negotiated after the passage of the 1990 CAAA show an implicit price of SO{sub 2} of approximately $50 per ton, an amount much closer to the eventual permit price. The implicit market price of sulfur seems to have revealed better information than did the calculations of industry experts.

  3. Modeling study of air pollution due to the manufacture of export goods in China's Pearl River Delta

    SciTech Connect

    David G. Streets; Carolyne Yu; Michael H. Bergin; Xuemei Wang; Gregory R. Carmichael

    2006-04-01

    The Pearl River Delta is a major manufacturing region on the south coast of China that produces more than $100 billion of goods annually for export to North America, Europe, and other parts of Asia. Considerable air pollution is caused by the manufacturing industries themselves and by the power plants, trucks, and ships that support them. It is estimated that 10-40% of emissions of primary SO{sub 2}, NOx, RSP, and VOC in the region are caused by export-related activities. Using the STEM-2K1 atmospheric transport model, it is estimated that these emissions contribute 5-30% of the ambient concentrations of SO{sub 2}, NOx, NOz, and VOC in the region. (NO{sub Z}=PAN, HONO, HNO{sub 3}, N{sub 2}O{sub 5} and organic nitrates). One reason that the exported goods are cheap and therefore attractive to consumers in developed countries is that emission controls are lacking or of low performance. It is estimated that state-of-the-art controls could be installed at an annualized cost of $0.3-3 billion, representing 0.3-3% of the value of the goods produced. Mitigation measures could be adopted without seriously affecting the prices of exported goods and would achieve considerable human health and other benefits in the form of reduced air pollutant concentrations in densely populated urban areas. 22 refs., 5 figs., 5 tabs.

  4. Urban air quality of Kathmandu valley

    SciTech Connect

    Sharma, C.K.

    1996-12-31

    The oval shaped tectonic basin of Kathmandu valley occupying about 600 sq. km. of area is situated in the middle sector of Himalayan range. There are three districts in the alley, i.e. Kathmandu, Litilpur, and Bhaktapur. Out of the three the most populated is the Kathmandu city (the capital of Kingdom of Nepal) which has 668,000 population in an area of approximately 50 sq. km. The city population consumes energy about 1/3 of total imports of Nepal in the form of gasoline, diesel, kerosene, furnace oil and cooking gas. This has resulted heavy pollution of air in the city leading bronchitis, and throat and chest diseases. Vehicle has increased several fold leading in recent months to 100,000 in number in a road of about 900 kms., out of which 25% is only metalled. Most of two and three wheelers are polluting the air by emission gases as well as dust particulate. SO{sub 2} has been found to go as high as 202 micro grams per cubic meter and NO{sub 2} to 126 micro gram particularly in winter months when a thick layer of fog covers the valley up to 10:00 AM in the morning. All the gases are mixed within the limited air below the fog and the ground. This creates the problem. Furthermore, municipal waste of 500 m{sup 3} a day and also liquid waste directly dumping in Bagmati river to the tune of 500,000 liters per day makes city ugly and filthy. Unless pollution of air, water, and land are controlled in time, Nepal will lose much of its foreign exchange earnings from tourist industry. It is found that tourist arrivals are considerably reduced in recent years and most of hotels occupancy is 50 to 60% in peak time. Nepal is trying to introduce legal frame work for pollution control but it will take time to be effective like in other developing countries unless government is strong.

  5. Overview and discussion of the key regulatory issues in implementing the electric utility provisions of the Clean Air Act Amendments of 1990

    SciTech Connect

    Rose, K.; Burns, R.E.

    1991-06-01

    Title 4 of the Clean Air Act Amendments of 1990 (CAAA) created a new regulatory instrument that electric power producers (utilities and others) will be required to possess and expand in order to emit sulfur dioxide (SO{sub 2}) into the atmosphere. The emission allowance system created by the CAAA will be grafted onto an already complex system of state and federal electric utility regulation. How public utility commissions (PUCs) and the Federal Energy Regulatory Commission (FERC) regulate these allowances will greatly affect the decisions that electric utilities under their jurisdiction make to comply with the CAAA and, therefore, the cost of compliance to ratepayers. 2 figs., 9 tabs.

  6. Predictors of alveolar air leaks.

    PubMed

    Loran, David B; Woodside, Kenneth J; Cerfolio, Robert J; Zwischenberger, Joseph B

    2002-08-01

    Persistent air leaks are caused by the failure of the postoperative lung to achieve a configuration that is physiologically amenable to healing. The raw pulmonary surface caused by the dissection of the fissure often is separated from the pleura, and the air leak fails to close. Additionally, higher air flow thorough an alveolar-pleural fistula seems to keep the fistula open. Other factors that interfere with wound healing, such as steroid use, diabetes, or malnutrition, can result in persistence of the leak. A thoracic surgeon can minimize the incidence of air leak through meticulous surgical technique and can identify patients in whom the balance of risks (Table 1) and benefits warrant operative intervention based on an understanding of the underlying pathophysiology.

  7. Manual on indoor air quality

    SciTech Connect

    Diamond, R.C.; Grimsrud, D.T.

    1983-12-01

    This reference manual was prepared to assist electric utilities in helping homeowners, builders, and new home buyers to understand a broad range of issues related to indoor air quality. The manual is directed to technically knowledgeable persons employed by utility companies - the customer service or marketing representative, applications engineer, or technician - who may not have specific expertise in indoor air quality issues. In addition to providing monitoring and control techniques, the manual summarizes the link between pollutant concentrations, air exchange, and energy conservation and describes the characteristics and health effects of selected pollutants. Where technical information is too lengthy or complex for inclusion in this volume, reference sources are given. Information for this manual was gathered from technical studies, manufacturers' information, and other materials from professional societies, institutes, and associations. The aim has been to provide objective technical and descriptive information that can be used by utility personnel to make informed decisions about indoor air quality issues.

  8. 20. Photographic copy of an asconstructed site plan for additions ...

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

    20. Photographic copy of an as-constructed site plan for additions to North Base: Job No. A(8-1), Military Construction, Materiel Command Flight Test Base, Muroc, California; Additional Construction, Location Plan, Sheet No. 2, October 1943. Reproduced from the holdings of the National Archives, Pacific Southwest Region - Edwards Air Force Base, North Base, North Base Road, Boron, Kern County, CA

  9. Community air monitoring and the Village Green Project

    EPA Science Inventory

    Abstract: Cost and logistics are practical issues that have historically constrained the number of locations where long-term, active air pollution measurement is possible. In addition, traditional air monitoring approaches are generally conducted by technical experts with limite...

  10. Community air monitoring and the Village Green Project

    EPA Science Inventory

    Cost and logistics are practical issues that have historically constrained the number of locations where long-term, active air pollution measurement is possible. In addition, traditional air monitoring approaches are generally conducted by technical experts with limited engageme...

  11. Air Leakage and Air Transfer Between Garage and Living Space

    SciTech Connect

    Rudd, A.

    2014-09-01

    This research project focused on evaluation of air transfer between the garage and living space in a single-family detached home constructed by a production homebuilder in compliance with the 2009 International Residential Code and the 2009 International Energy Conservation Code. The project gathered important information about the performance of whole-building ventilation systems and garage ventilation systems as they relate to minimizing flow of contaminated air from garage to living space. A series of 25 multi-point fan pressurization tests and additional zone pressure diagnostic testing characterized the garage and house air leakage, the garage-to-house air leakage, and garage and house pressure relationships to each other and to outdoors using automated fan pressurization and pressure monitoring techniques. While the relative characteristics of this house may not represent the entire population of new construction configurations and air tightness levels (house and garage) throughout the country, the technical approach was conservative and should reasonably extend the usefulness of the results to a large spectrum of house configurations from this set of parametric tests in this one house. Based on the results of this testing, the two-step garage-to-house air leakage test protocol described above is recommended where whole-house exhaust ventilation is employed. For houses employing whole-house supply ventilation (positive pressure) or balanced ventilation (same pressure effect as the Baseline condition), adherence to the EPA Indoor airPLUS house-to-garage air sealing requirements should be sufficient to expect little to no garage-to-house air transfer.

  12. Intra-urban variability of air pollution in Windsor, Ontario-Measurement and modeling for human exposure assessment

    SciTech Connect

    Wheeler, Amanda J. Smith-Doiron, Marc; Xu Xiaohong; Gilbert, Nicolas L.; Brook, Jeffrey R.

    2008-01-15

    There are acknowledged difficulties in epidemiological studies to accurately assign exposure to air pollution for large populations, and large, long-term cohort studies have typically relied upon data from central monitoring stations. This approach has generally been adequate when populations span large areas or diverse cities. However, when the effects of intra-urban differences in exposure are being studied, the use of these existing central sites are likely to be inadequate for representing spatial variability that exists within an urban area. As part of the Border Air Quality Strategy (BAQS), an international agreement between the governments of Canada and the United States, a number of air health effects studies are being undertaken by Health Canada and the US EPA. Health Canada's research largely focuses on the chronic exposure of elementary school children to air pollution. The exposure characterization for this population to a variety of air pollutants has been assessed using land-use regression (LUR) models. This approach has been applied in several cities to nitrogen dioxide (NO{sub 2}), as an assumed traffic exposure marker. However, the models have largely been developed from limited periods of saturation monitoring data and often only represent one or two seasons. Two key questions from these previous efforts, which are examined in this paper, are: If NO{sub 2} is a traffic marker, what other pollutants, potentially traffic related, might it actually represent? How well is the within city spatial variability of NO{sub 2}, and other traffic-related pollutants, characterized by a single saturation monitoring campaign. Input data for the models developed in this paper were obtained across a network of 54 monitoring sites situated across Windsor, Ontario. The pollutants studied were NO{sub 2}, sulfur dioxide (SO{sub 2}) and volatile organic compounds, which were measured in all four seasons by deploying passive samplers for 2-week periods. Correlations

  13. Remote air pollution measurement

    NASA Technical Reports Server (NTRS)

    Byer, R. L.

    1975-01-01

    This paper presents a discussion and comparison of the Raman method, the resonance and fluorescence backscatter method, long path absorption methods and the differential absorption method for remote air pollution measurement. A comparison of the above remote detection methods shows that the absorption methods offer the most sensitivity at the least required transmitted energy. Topographical absorption provides the advantage of a single ended measurement, and differential absorption offers the additional advantage of a fully depth resolved absorption measurement. Recent experimental results confirming the range and sensitivity of the methods are presented.

  14. Low-threshold bidirectional air lasing.

    PubMed

    Laurain, Alexandre; Scheller, Maik; Polynkin, Pavel

    2014-12-19

    Air lasing refers to the remote optical pumping of the constituents of ambient air that results in a directional laserlike emission from the pumped region. Intense current investigations of this concept are motivated by the potential applications in remote atmospheric sensing. Different approaches to air lasing are being investigated, but, so far, only the approach based on dissociation and resonant two-photon pumping of air molecules by deep-UV laser pulses has produced measurable lasing energies in real air and in the backward direction, which is of the most relevance for applications. However, the emission had a high pumping threshold, in hundreds of GW/cm^{2}. We demonstrate that the threshold can be virtually eliminated through predissociation of air molecules with an additional nanosecond laser. We use a single tunable pump laser system to generate backward-propagating lasing in both oxygen and nitrogen in air, with energies of up to 1  μJ per pulse.

  15. Temperature-induced changes in the single-crystal structure of K{sub 9}H{sub 7}(SO{sub 4}){sub 8} {center_dot} H{sub 2}O

    SciTech Connect

    Makarova, I. P. Grebenev, V. V.; Chernaya, T. S.; Verin, I. A.; Dolbinina, V. V.; Chernyshov, D. Yu.; Koval'chuk, M. V.

    2013-05-15

    Interest in superprotonic crystals of M{sub m}H{sub n}(XO{sub 4}){sub (m+n)/2} is associated with the solution to the fundamental problem of modern condensed matter physics: investigations of structural phase transitions and the stabilization of phases with high proton conductivity with the aim of designing new functional materials. The available data suggest that changes in the physical properties in these crystals can occur through different structural mechanisms. To reveal the structural conditionality for anomalies in the physical properties, the crystals of K{sub 9}H{sub 7}(SO{sub 4}){sub 8} {center_dot} H{sub 2}O were studied by X-ray diffraction in the temperature range of 25-463 K, and the crystal structure of the high-temperature phase was determined at 418 K (sp. gr. Pcan). The results of the study indicate that the occurrence of high conductivity in K{sub 9}H{sub 7}(SO{sub 4}){sub 8} {center_dot} H{sub 2}O crystals at high temperatures is associated with the diffusion of water of crystallization, the hydrogen-bond network rearrangement, and the motion of K ions. The hydrogen-bond rearrangement and the hindered back diffusion of water to the crystal stabilize the high-temperature phase and ensure its supercooling to low temperatures.

  16. Survey of European technology developments of SO/sub x//NO/sub x/ flue gas clean up for coal-fired boilers, also free piston stirling engines and coal tar burning diesel engines

    SciTech Connect

    Not Available

    1980-10-01

    In an effort to identify advanced RD and D projects as candidates for joint ventures and/or introduction to the US, European technology developments in the area of flue gas cleanup were surveyed. This survey covers both wet and dry scrubbers for coal-fired boilers and includes advanced systems for removal of SO/sub x/ or combined SO/sub x//NO/sub x/ removal. Information on lime/limestone scrubbers is limited to a tabulation of commercial sized installations. Emphasis is based on demonstrations and suggestions are provided as to why the particular projects are considered to be in advance of US technology. Areas of Europe covered are Austria, Belgium, Denmark, France, Germany, Italy, Netherlands, Norway and Sweden. With a lower priority, Austria, Spain, and Switzerland were screened for the existence of relevant work. This survey allows the following tentative conclusions: (1) the most relevant work is performed in Germany and Scandinavia (Denmark, Norway and Sweden). Work of some relevance was identified in the Netherlands and Italy; and (2) except for Germany, where FGD is applied commercially, no coal-fired lime/limestone scrubbers are operating commercially in the surveyed countries. (Outside Germany, the only operating lime/limestone scrubber is a 35 MW oil-fired unit in Stockholm). Four processes examined in Germany are described in some detail.

  17. 32 CFR 809a.9 - Conditions for use of Air Force resources.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... is not intended to extend Air Force responsibilities in emergencies to generate additional resources... but near an Air Force installation, thereby necessitating Air Force assumption of responsibility... disaster compels immediate action to protect life and property and to restore order....

  18. 32 CFR 809a.9 - Conditions for use of Air Force resources.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... is not intended to extend Air Force responsibilities in emergencies to generate additional resources... but near an Air Force installation, thereby necessitating Air Force assumption of responsibility... disaster compels immediate action to protect life and property and to restore order....

  19. Metal-Air Batteries

    SciTech Connect

    Zhang, Jiguang; Bruce, Peter G.; Zhang, Gregory

    2011-08-01

    Metal-air batteries have much higher specific energies than most currently available primary and rechargeable batteries. Recent advances in electrode materials and electrolytes, as well as new designs on metal-air batteries, have attracted intensive effort in recent years, especially in the development of lithium-air batteries. The general principle in metal-air batteries will be reviewed in this chapter. The materials, preparation methods, and performances of metal-air batteries will be discussed. Two main metal-air batteries, Zn-air and Li-air batteries will be discussed in detail. Other type of metal-air batteries will also be described.

  20. Air pollution and survival within the Washington University-EPRI Veterans Cohort: risks based on modelled estimates of ambient levels of hazardous and criteria air pollutants

    SciTech Connect

    Frederick W. Lipfert; Ronald E. Wyzga; Jack D. Baty; J. Philip Miller

    2009-04-15

    For this paper, we considered relationships between mortality, vehicular traffic density, and ambient levels of 12 hazardous air pollutants, elemental carbon (EC), oxides of nitrogen (NOx), sulfur dioxide (SO{sub 2}), and sulfate (SO{sub 4}{sup -2}). These pollutant species were selected as markers for specific types of emission sources, including vehicular traffic, coal combustion, smelters, and metal-working industries. Pollutant exposures were estimated using emissions inventories and atmospheric dispersion models. We analyzed associations between county ambient levels of these pollutants and survival patterns among approximately 70,000 U.S. male veterans by mortality period (1976-2001 and subsets), type of exposure model, and traffic density level. We found significant associations between all-cause mortality and traffic-related air quality indicators and with traffic density per se, with stronger associations for benzene, formaldehyde, diesel particulate, NOx, and EC. The maximum effect on mortality for all cohort subjects during the 26-yr follow-up period is approximately 10%, but most of the pollution-related deaths in this cohort occurred in the higher-traffic counties, where excess risks approach 20%. However, mortality associations with diesel particulates are similar in high- and low-traffic counties. Sensitivity analyses show risks decreasing slightly over time and minor differences between linear and logarithmic exposure models. We conclude that tailpipe emissions of both gases and particles are among the most significant and robust predictors of mortality in this cohort and that most of those associations have weakened over time. There may be concerns associated with large stationary sources burning coal, residual fuel oil and municipal solid wastes. Nickel and arsenic have been identified in coal fly ash and residual oil. 81 refs., 3 figs., 7 tabs.