Note: This page contains sample records for the topic atmospheric fluidized-bed coal from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: August 15, 2014.
1

Coal and limestone feed testing for atmospheric fluidized bed combustion  

SciTech Connect

Pneumatic conveying tests of coal and coal-limestone mixtures were performed on a conveying system designed to represent the branch feed lines in the TVA 20 MW(e) atmospheric fluidized bed combustor pilot plant. Test conditions were chosen to cover the operating ranges anticipated for the pilot plant. These tests have led to a basic understanding of the design and operating problems associated with coal surface moisture, air velocity, fines content, solids loading, and limestone to coal ratio. Coal surface moisture was found to be the most important parameter affecting handling properties. Above a critical level of about 6%, surface moisture caused severe compaction problems in the feed hopper and impact plugging in the conveyor line. When surface moisture was less than 6%, conveyor line plugging resulted only from saltation and filling. Limestone addition reduced the problems associated with wet coal. Coal with up to 17% surface moisture was successfully conveyed by adding dry limestone at a level of 0.5 kg limestone per kg of wet coal. Practical operating limits for saltation and surge flow were also developed. In general, it is recommended that superficial air velocity be kept greater than 16.8 m/s (55 ft/s) everywhere in the conveyor line during coal-limestone flow. When saltation or plugging do not occur, frictional pressure drop is only a function of the solids loading and the air flow conditions. A general correlation was developed to describe this relationship.

Daw, C.S.; Thomas, J.F.; Lackey, M.E.

1981-09-01

2

Fluidized Bed Coal Liquefaction.  

National Technical Information Service (NTIS)

Coal is catalytically hydropyrolyzed at temperatures of 500 C to 700 C and pressures of 1000 psi to 4000 psi to form a liquefied product comprising gasoline and middle distillate fuel and diesel oils by forming a fluidized bed of coal in hot hydrogen or h...

S. A. Qader

1983-01-01

3

Theoretical Cost Estimates for a Coal-Fired Atmospheric Fluidized-Bed Boiler.  

National Technical Information Service (NTIS)

This paper contains the development of a costing method for coal-fired atmospheric fluidized-bed (AFB) boilers and the results of applying this method to a 200,000 lb/h boiler. The costs of concern are capital costs. The hardwares are those components att...

V. T. Nguyen M. T. Lethi

1981-01-01

4

Fluidized bed approach under development for coal combustion  

Microsoft Academic Search

The new combustion technique of burning coal in a fluidized bed and its efficiency and applications are described. Proposals have been drawn up to use coal-fired fluidized bed combustors in large industrial gas turbines. Such units should find particularly rewarding applications where both the power output and exhaust heat can be employed. Fluidized-bed combustion of coal in smaller atmospheric boilers

Harboe

1976-01-01

5

Pulsed atmospheric fluidized bed combustor apparatus  

Microsoft Academic Search

A pulsed atmospheric fluidized bed reactor system is disclosed and claimed along with a process for utilization of same for the combustion of, e.g. high sulfur content coal. The system affords a economical, ecologically acceptable alternative to oil and gas fired combustors. The apparatus may also be employed for endothermic reaction, combustion of waste products, e.g., organic and medical waste,

Mansour; Momtaz N

1993-01-01

6

Pulsed atmospheric fluidized bed combustion  

SciTech Connect

During this first quarter, a lab-scale water-cooled pulse combustor was designed, fabricated, and integrated with old pilot-scale PAFBC test systems. Characterization tests on this pulse combustor firing different kinds of fuel -- natural gas, pulverized coal and fine coal -- were conducted (without fluidized bed operation) for the purpose of finalizing PAFBC full-scale design. Steady-state tests were performed. Heat transfer performance and combustion efficiency of a coal-fired pulse combustor were evaluated.

Not Available

1992-05-01

7

Theoretical cost estimates for a coal-fired atmospheric fluidized-bed boiler  

SciTech Connect

This paper contains the development of a costing method for coal-fired atmospheric fluidized-bed (AFB) boilers and the results of applying this method to a 200,000 lb/h boiler. The costs of concern are capital costs. The hardwares are those components attached to the boiler unit, and do not include auxiliary equipment. Costs are expressed in 1979 dollars and include shop fabrication, freight, site preparation, field erection, engineering and construction overhead costs. The installed stripped cost of a 200,000 lb/h AFB boiler is estimated to be $2 million to $2.2 million, depending on the type of coal used. With added contingency, markup, profit and project fee, the calculated cost of the boiler unit varies between $3.06 million to $3.3 million. Assuming that the costs of fabrication materials is 100% above the chosen lowest cost assumed, the cost of the boiler unit increases by 54.5% above the calculated cost.

Nguyen, V.T.; Lethi, M.T.

1981-10-01

8

Atmospheric fluidized-bed combustion (AFBC) co-firing of coal and hospital waste. Environmental Assessment  

SciTech Connect

The proposed project involves co-firing of coal and medical waste (including infectious medical waste) in an atmospheric fluidized-bed combustor (AFBC) to safely dispose of medical waste and produce steam for hospital needs. Combustion at the design temperature and residence time (duration) in the AFBC has been proven to render infectious medical waste free of disease producing organisms. The project would be located at the Veterans Affairs (VA) Medical Center in Lebanon, Pennsylvania. The estimated cost of the proposed AFBC facility is nearly $4 million. It would be jointly funded by DOE, Veterans Affairs, and Donlee Technologies, Inc., of York, Pennsylvania, under a cooperative agreement between DOE and Donlee. Under the terms of this agreement, $3.708 million in cost-shared financial assistance would be jointly provided by DOE and the Veterans Affairs (50/50), with $278,000 provided by Donlee. The purposes of the proposed project are to: (1) provide the VA Medical Center and the Good Samaritan Hospital (GSH), also of Lebanon, Pennsylvania, with a solution for disposal of their medical waste; and (2) demonstrate that a new coal-burning technology can safely incinerate infectious medical waste, produce steam to meet hospital needs, and comply with environmental regulations.

Not Available

1993-02-01

9

Pulsed atmospheric fluidized bed combustor apparatus  

DOEpatents

A pulsed atmospheric fluidized bed reactor system is disclosed and claimed along with a process for utilization of same for the combustion of, e.g. high sulfur content coal. The system affords a economical, ecologically acceptable alternative to oil and gas fired combustors. The apparatus may also be employed for endothermic reaction, combustion of waste products, e.g., organic and medical waste, drying materials, heating air, calcining and the like.

Mansour, Momtaz N. (Columbia, MD)

1993-10-26

10

Fluidized bed coal combustion reactor  

NASA Technical Reports Server (NTRS)

A fluidized bed coal reactor includes a combination nozzle-injector ash-removal unit formed by a grid of closely spaced open channels, each containing a worm screw conveyor, which function as continuous ash removal troughs. A pressurized air-coal mixture is introduced below the unit and is injected through the elongated nozzles formed by the spaces between the channels. The ash build-up in the troughs protects the worm screw conveyors as does the cooling action of the injected mixture. The ash layer and the pressure from the injectors support a fluidized flame combustion zone above the grid which heats water in boiler tubes disposed within and/or above the combustion zone and/or within the walls of the reactor.

Moynihan, P. I.; Young, D. L. (inventors)

1981-01-01

11

Fluidized bed combustion of coal  

NASA Astrophysics Data System (ADS)

The effect of various parameters on combustion efficiency, desulfurization efficiency and NO emission in fluidized bed combustion of coal were investigated by using two test combustors whose sectional areas were 200 mm and 500 mm square. It has been revealed that by employing two-stage combustion and setting the primary air ratio, secondary air injection height and other parameters to optimum levels, NO emission can be greatly reduced while barely impairing combustion efficiency or desulfurization efficiency. Also, NO emission of less than 50 ppm and desulfurization efficiency of as high as 93% were achieved. These results have ensured good prospects for the development of a coal combustion boiler system which can satisfy the strictest environmental protection regulations, without installing special desulfurization and de-NO(X) facilities.

Tatebayashi, J.; Okada, Y.; Yano, K.; Takada, T.; Handa, K.

12

An atmospheric pressure, fluidized bed combustion system burning high-chlorine coals in the convection section  

SciTech Connect

The possibility of fireside corrosion in power plant boiler components is always a major concern when the fuels include high-sulfur and high-chlorine coals (or refuse waste). Sulfur and chloride products may play important roles especially in fireside corrosion in atmospheric pressure, fluidized bed combustion (AFBC) systems, caused by the capture of sulfur and chlorine by limestone used as bed material in the combustor, and the resulting deposition of sulfur- or chlorine-rich compounds onto metallic surfaces. Results were reported from tests in a 0.1-MW{sub th} AFBC system where 1,000-h test burns were conducted using two coals with widely differing chlorine levels, and limestone was used as the sulfur sorbent. Coupons of three stainless steels (Types 304 [UNS S30400], 309 [UNS S30900], 347 [UNS S34700]) were exposed to the hot flue gases in the freeboard ({approximately} 10- cm below the location of the convection pass tubes). Deposits formed on the alloys contained high sulfur concentrations in their outer parts, as well as sodium, potassium, magnesium, and calcium. Sulfur appeared to be associated with calcium and magnesium, suggesting that the fly ash may have reacted further after being deposited on the surface of the coupon. Areas of high sulfur concentration also correlated well with areas of high chromium content of the inner layers of the scales. cross sections of samples indicated that sulfur had penetrated into the alloy and reacted to form sulfide corrosion products. There was no direct evidence to show that alkali chlorides were involved in the corrosion process. No chloride was identified in the alloy samples. There was slight oxide spallation observed on all three alloys, with the degree of spallation in the following order: Type 304 > Type 347 > Type 309.

Liu, K.; Xie, W.; Pan, W.P.; Riley, J.T.

2000-03-01

13

Gasification of coal and PET in fluidized bed reactor  

Microsoft Academic Search

Blended fuel comprising 23wt.% polyethyleneterephthalate (PET) and 77wt.% brown coal was gasified in an atmospheric fluidized bed gasifier of laboratory-scale. The gasification agent was composed of 10vol.% O2 in bulk of nitrogen. Thermal and texture analyses were carried out to determine the basic properties of the fuel components. The influence of experimental conditions, such as the fluidized bed and freeboard

M. Poho?elý; M. Vosecký; P. Hejdová; M. Pun?ochá?; S. Skoblja; M. Staf; J. Vošta; B. Koutský; K. Svoboda

2006-01-01

14

Fluidized bed selective pyrolysis of coal  

DOEpatents

The present invention discloses a process for the pyrolysis of coal which comprises the effective utilization of two zonal inclined fluidized beds, where said zones can be selectively controlled as to temperature and heating rate. The first zonal inclined fluidized bed serves as a dryer for crushed coal and additionally is controlled to selectively pyrolyze said coal producing substantially carbon dioxide for recycle use. The second zonal inclined fluidized bed further pyrolyzes the coal to gaseous, liquid and char products under controlled temperature and heating rate zones designed to economically integrate the product mix. The gas and liquid products are recovered from the gaseous effluent stream while the char which remains can be further treated or utilized in a subsequent process step.

Shang, Jer Y. (McLean, VA); Cha, Chang Y. (Golden, CO); Merriam, Norman W. (Laramie, WY)

1992-01-01

15

Fluidized bed selective pyrolysis of coal  

DOEpatents

The present invention discloses a process for the pyrolysis of coal which comprises the effective utilization of two zonal inclined fluidized beds, where said zones can be selectively controlled as to temperature and heating rate. The first zonal inclined fluidized bed serves as a dryer for crushed coal and additionally is controlled to selectively pyrolyze said coal producing substantially carbon dioxide for recycle use. The second zonal inclined fluidized bed further pyrolyses the coal to gaseous, liquid and char products under controlled temperature and heating rate zones designed to economically integrate the product mix. The gas and liquid products are recovered from the gaseous effluent stream while the char which remains can be further treated or utilized in a subsequent process step. 9 figs.

Shang, J.Y.; Cha, C.Y.; Merriam, N.W.

1992-12-15

16

Summary Evaluation of Atmosphere Pressure Fluidized Bed Combustion Applied to Electric Utility Large Steam Generators. Executive Summary.  

National Technical Information Service (NTIS)

An atmospheric pressure fluidized-bed combustor has been proposed as an alternative to the conventional pulverized coal boiler equipped with its tailend scrubbing system. The major potential advantages of fluidized-bed combustion are the removal of SO sub...

T. E. Dowdy W. C. Lapple J. B. Kitto T. P. Stanoch R. H. Boll

1976-01-01

17

Fluidized bed catalytic coal gasification process  

DOEpatents

Coal or similar carbonaceous solids impregnated with gasification catalyst constituents (16) are oxidized by contact with a gas containing between 2 volume percent and 21 volume percent oxygen at a temperature between 50.degree. C. and 250.degree. C. in an oxidation zone (24) and the resultant oxidized, catalyst impregnated solids are then gasified in a fluidized bed gasification zone (44) at an elevated pressure. The oxidation of the catalyst impregnated solids under these conditions insures that the bed density in the fluidized bed gasification zone will be relatively high even though the solids are gasified at elevated pressure and temperature.

Euker, Jr., Charles A. (15163 Dianna La., Houston, TX 77062); Wesselhoft, Robert D. (120 Caldwell, Baytown, TX 77520); Dunkleman, John J. (3704 Autumn La., Baytown, TX 77520); Aquino, Dolores C. (15142 McConn, Webster, TX 77598); Gouker, Toby R. (5413 Rocksprings Dr., LaPorte, TX 77571)

1984-01-01

18

Nucla circulating atmospheric fluidized bed demonstration project  

SciTech Connect

Colorado-Ute Electric Association began a study to evaluate options for upgrading and extending the life of its Nucla power station in 1982. Located in southwestern Colorado near the town of Nucla, this station was commissioned in 1959 with a local bituminous coal as its design fuel for three identical stoker-fired units, each rated at 12.6 MW(e). Poor station efficiency, high fuel costs, and spiraling boiler maintenance costs forced the Nucla Station into low priority in the CUEA dispatch order as early as 1981. Among the options CUEA considered was to serve as a host utility to demonstrate Atmospheric Fluidized Bed Combustion (AFBC) technology. The anticipated environmental benefits and apparent attractive economics of a circulating AFBC led to Colorado-Ute's decision to proceed with the design and construction of a demonstration project in 1984 at the Nucla facility.

Not Available

1991-10-01

19

Pulsed atmospheric fluidized bed combustor apparatus and process  

Microsoft Academic Search

A pulsed atmospheric fluidized bed reactor system is disclosed and claimed along with a process for utilization of same for the combustion of, e.g. high sulfur content coal. The system affords a economical, ecologically acceptable alternative to oil and gas fired combustors. The apparatus may also be employed for endothermic reaction, combustion of waste products, e.g. organic and medical waste,

Mansour; Momtaz N

1992-01-01

20

Advanced Atmospheric Fluidized-Bed Combustion Design - Spouted Bed.  

National Technical Information Service (NTIS)

This report describes the Spouted-Fluidized Bed Boiler that is an advanced atmospheric fluidized bed combustor (FBC). The objective of this system design study is to develop an advanced AFBC with improved performance and reduced capital and operating cost...

F. W. Shirley R. D. Litt

1985-01-01

21

Atmospheric fluidized bed combustion advanced concept system  

SciTech Connect

DONLEE Technologies Inc. is developing with support of the US Department of Energy an advanced circulating fluidized bed technology known as the Vortex{trademark} Fluidized Bed Combustor (VFBC). The unique feature of the VFBC is the injection of a significant portion of the combustion air into the cyclone. Since as much as one-half of the total combustion air is injected into the cyclone, the cross-sectional area of the circulating fluidized bed is considerably smaller than typical circulating fluidized beds. The technology is being developed for two applications: Industrial-scale boilers ranging from 20,000 to 100,000 pounds per hour steam generating capacity; and two-stage combustion in which a substoichiometric Vortex Fluidized Bed Combustor (2VFBC) or precombustor is used to generate a combustible gas for use primarily in boiler retrofit applications. This Level II analysis of these two applications indicates that both have merit. An industrial-scale VFBC boiler (60,000 lb/hr of steam) is projected to be economically attractive with coal prices as high as $40 per ton and gas prices between $4 and $5 per thousand cubic feet. The payback time is between 3 and 4 years. The 2VFBC system was evaluated at three capacities of application: 20,000; 60,000 and 100,000 lb/hr of steam. The payback times for these three capacities are 4.5, 2.1 and 1.55 years, respectively. The 2VFBC has potential applications for retrofit of existing pulverized coal-fired boilers or as a new large (utility) boiler. Pressurized operation of the 2VFBC has considerable potential for combined cycle power generation applications. Experimental development of both applications is presented here to demonstrate the potential of these two technologies.

Not Available

1992-05-01

22

Fluidized bed gasification of extracted coal  

DOEpatents

Coal or similar carbonaceous solids are extracted by contacting the solids in an extraction zone with an aqueous solution having a pH above 12.0 at a temperature between 65/sup 0/C and 110/sup 0/C for a period of time sufficient to remove bitumens from the coal into said aqueous solution, and the extracted solids are then gasified at an elevated pressure and temperature in a fluidized bed gasification zone (60) wherein the density of the fluidized bed is maintained at a value above 160 kg/m/sup 3/. In a preferred embodiment of the invention, water is removed from the aqueous solution in order to redeposit the extracted bitumens onto the solids prior to the gasification step. 2 figs., 1 tab.

Aquino, D.C.; DaPrato, P.L.; Gouker, T.R.; Knoer, P.

1984-07-06

23

Fluidized bed gasification of extracted coal  

DOEpatents

Coal or similar carbonaceous solids are extracted by contacting the solids in an extraction zone (12) with an aqueous solution having a pH above 12.0 at a temperature between 65.degree. C. and 110.degree. C. for a period of time sufficient to remove bitumens from the coal into said aqueous solution and the extracted solids are then gasified at an elevated pressure and temperature in a fluidized bed gasification zone (60) wherein the density of the fluidized bed is maintained at a value above 160 kg/m.sup.3. In a preferred embodiment of the invention, water is removed from the aqueous solution in order to redeposit the extracted bitumens onto the solids prior to the gasification step.

Aquino, Dolores C. (Houston, TX); DaPrato, Philip L. (Westfield, NJ); Gouker, Toby R. (Baton Rouge, LA); Knoer, Peter (Houston, TX)

1986-01-01

24

Fluidized bed injection assembly for coal gasification  

DOEpatents

A coaxial feed system for fluidized bed coal gasification processes including an inner tube for injecting particulate combustibles into a transport gas, an inner annulus about the inner tube for injecting an oxidizing gas, and an outer annulus about the inner annulus for transporting a fluidizing and cooling gas. The combustibles and oxidizing gas are discharged vertically upward directly into the combustion jet, and the fluidizing and cooling gas is discharged in a downward radial direction into the bed below the combustion jet.

Cherish, Peter (Bethel Park, PA); Salvador, Louis A. (Hempfield Township, Westmoreland County, PA)

1981-01-01

25

NUCLA Circulating Atmospheric Fluidized Bed Demonstration Project  

SciTech Connect

This Annual Report on Colorado-Ute Electric Association's NUCLA Circulating Fluidized Bed (CFB) Demonstration Program covers the period from February 1987 through December 1988. The outline for presentation in this report includes a summary of unit operations along with individual sections covering progress in study plan areas that commenced during this reporting period. These include cold-mode shakedown and calibration, plant commercial performance statistics, unit start-up (cold), coal and limestone preparation and handling, ash handling system performance and operating experience, tubular air heater, baghouse operation and performance, materials monitoring, and reliability monitoring. During this reporting period, the coal-mode shakedown and calibration plan was completed. (VC)

Not Available

1991-01-01

26

Simulation of fluidized bed coal combustors  

NASA Technical Reports Server (NTRS)

The many deficiencies of previous work on simulation of fluidized bed combustion (FBC) processes are presented. An attempt is made to reduce these deficiencies, and to formulate a comprehensive FBC model taking into account the following elements: (1) devolatilization of coal and the subsequent combustion of volatiles and residual char; (2) sulfur dioxide capture by limestone; (3) NOx release and reduction of NOx by char; (4) attrition and elutriation of char and limestone; (5) bubble hydrodynamics; (6) solids mixing; (7) heat transfer between gas and solid, and solid and heat exchange surfaces; and (8) freeboard reactions.

Rajan, R.

1979-01-01

27

Pulsed atmospheric fluidized bed combustor apparatus and process  

DOEpatents

A pulsed atmospheric fluidized bed reactor system is disclosed and claimed along with a process for utilization of same for the combustion of, e.g. high sulfur content coal. The system affords a economical, ecologically acceptable alternative to oil and gas fired combustors. The apparatus may also be employed for endothermic reaction, combustion of waste products, e.g. organic and medical waste, drying, calcining and the like.

Mansour, Momtaz N. (Columbia, MD) [Columbia, MD

1992-01-01

28

International energy technology assessment: Atmospheric fluidized-bed combustion  

NASA Astrophysics Data System (ADS)

A survey was made of atmospheric fluidized bed combustion (AFBC) research and development and commercial activities in foreign countries. These activities indicate a broad interest in the process largely because of its flexibility in burning a wide range of coals and low grade fuels. The conclusion is made that AFBC is a viable system and is in the process of being confirmed on a commercial scale for industrial heat and power generation. A number of organizations in the United States and western Europe are offering fluidized bed package boilers, with some form of commercial guarantees. The major uncertainties of the process lie in the areas of coal and sorbent handling systems, availability of reliable construction materials; the system's ability to meet varying load demands; reduced sorbent requirements; and improved carbon utilization. Research and development programs in these areas are being pursued.

Krishnan, R. P.; Johnsson, K. O.

1982-04-01

29

COSTEAM expansion and improvements: design of a coal-fired atmospheric fluidized bed submodel, an oil-fired submodel and input/output improvements  

SciTech Connect

COSTEAM is an interactive computer model designed to estimate the cost of industrial steam produced by various steam plant technologies. At the end of Phase I development, the COSTEAM model included only one submodel to calculate the capital and operating costs of a conventional coal-fired boiler plant with environmental control systems. This report describes the results of Phase II development. Two new submodels are added which calculate costs for steam produced by coal-fired atmospheric fluidized bed boilers and by oil-fired boilers. COSTEAM input/output capabilities are also improved.

Reierson, James D.; Rosenberg, Joseph I.; Murphy, Mary B.; Lethi, Minh- Triet

1980-10-01

30

Pulsed atmospheric fluidized bed combustion. Final report  

SciTech Connect

ThermoChem, under contract to the Department of Energy, conducted extensive research, development and demonstration work on a Pulsed Atmospheric Fluidized Bed Combustor (PAFBC) to confirm that advanced technology can meet these performance objectives. The ThermoChem/MTCI PAFBC system integrates a pulse combustor with an atmospheric bubbling-bed type fluidized bed combustor (BFBC) In this modular configuration, the pulse combustor burns the fuel fines (typically less than 30 sieve or 600 microns) and the fluidized bed combusts the coarse fuel particles. Since the ThermoChem/MTCI PAFBC employs both the pulse combustor and the AFBC technologies, it can handle the full-size range of coarse and fines. The oscillating flow field in the pulse combustor provides for high interphase and intraparticle mass transfer rates. Therefore, the fuel fines essentially burn under kinetic control. Due to the reasonably high temperature (>1093 C but less than the temperature for ash fusion to prevent slagging), combustion of fuel fines is substantially complete at the exit of the pulse combustor. The additional residence time of 1 to 2 seconds in the freeboard of the PAFBC unit then ensures high carbon conversion and, in turn, high combustion efficiency. A laboratory unit was successfully designed, constructed and tested for over 600 hours to confirm that the PAFBC technology could meet the performance objectives. Subsequently, a 50,000 lb/hr PAFBC demonstration steam boiler was designed, constructed and tested at Clemson University in Clemson, South Carolina. This Final Report presents the detailed results of this extensive and successful PAFBC research, development and demonstration project.

NONE

1998-03-01

31

Atmospheric fluidized bed combustor development program. Final report  

SciTech Connect

The objective of this project was to demonstrate and promote the commercialization of a coal-fired atmospheric fluidized bed combustion (AFBC) system, with limestone addition for SO{sub 2} emissions control and a baghouse for particulate emissions control. This AFBC system was targeted for small scale industrial-commercial-institutional space and process heat applications in the 1 x 10{sup 6} to 10 x 10{sup 6} Btu/hr capacity range. A cost effective and environmentally acceptable AFBC technology in this size range would displace a considerable amount of gas/oil with coal while resulting in significant total cost savings to the owner/operators. The project itself was separated into three levels: (1) feasibility, (2--3) subsystem development and integration, and (4) proof-of-concept. In Level (1), the technical and economic feasibility of a 1 million Btu/hr coal-fired AFBC air heater was evaluated. In Level (2--3), the complete EER fluidized bed combustor (1.5 million Btu/hr) system was developed and tested. The goal or reducing SO{sub 2} emissions to 1.2 lb/10{sup 6} Btu, from high sulfur Ohio coal, was achieved by adding limestone with a Ca/S (coal) ratio of {approximately} 3.0. Finally, in Level (4), the proof-of-concept system, a 2.2 million Btu/hr unit was installed and successfully operated at Cedar Lane Farms, a commercial nursery in Ohio.

Ashworth, R.A.; Melick, T.A.; Plessinger, D.A.; Sommer, T.M. [Energy and Environmental Research Corp., Orville, OH (United States); Keener, H.M. [Ohio State Univ., Columbus, OH (United States). Ohio Agricultural Research and Development Center; Webner, R.L. [Will-Burt, Orrville, OH (United States)

1995-12-01

32

MONITORING STRATEGIES FOR FLUIDIZED BED COMBUSTION COAL PLANTS  

EPA Science Inventory

Air and water monitoring strategies for commercial-size Fluidized Bed Combustion (FBC) coal plants are presented. This is one of five reports developing air and water monitoring strategies for advanced coal combustion (FBC), coal conversion (coal gasification and liquefaction), a...

33

Fine Coal Beneficiation using an Air Dense Medium Fluidized Bed  

Microsoft Academic Search

The potential of using Air Dense Medium Fluidized Bed (ADMFB) separation for cleaning sub-bituminous coal was investigated. The effect of operating parameters such as the fluidizing air velocity and medium particle size on separation efficiency was determined with coal of various size fractions. Good separation efficiencies with raw coal in the 6 to 1 mm size fraction were achieved. Partition curves

J. Choung; C. Mak; Z. Xu

2006-01-01

34

MATHEMATICAL MODEL FOR A FLUIDIZED-BED COAL GASIFIER  

EPA Science Inventory

The report gives results of gasifying four fuels--a devolatilized Kentucky bituminous coal, a New Mexico subbituminous coal, a North Carolina peat, and a Texas lignite--with steam and oxygen in a pilot-scale fluidized-bed reactor. Experimental results were used to provide an eval...

35

Fluidized bed combustor and coal gun-tube assembly therefor  

DOEpatents

A coal supply gun assembly for a fluidized bed combustor which includes heat exchange elements extending above the bed's distributor plate assembly and in which the gun's nozzles are disposed relative to the heat exchange elements to only discharge granular coal material between adjacent heat exchange elements and in a path which is substantially equidistant from adjacent heat exchange elements.

Hosek, William S. (Mt. Tabor, NJ); Garruto, Edward J. (Wayne, NJ)

1984-01-01

36

Fluidized-bed combustion reduces atmospheric pollutants  

NASA Technical Reports Server (NTRS)

Method of reducing sulfur and nitrogen oxides released during combustion of fossil fuels is described. Fuel is burned in fluidized bed of solids with simultaneous feeding of crushed or pulverized limestone to control emission. Process also offers high heat transfer rates and efficient contacting for gas-solid reactions.

Jonke, A. A.

1972-01-01

37

Metallic species derived from fluidized bed coal combustion. [59 references  

SciTech Connect

Samples of fly ash generated by the combustion of Montana Rosebud coal in an experimental 18 inch fluidized bed combustor were collected. The use of a heated cascade impactor permitted collection of size fractionated material that avoided condensation of volatile gases on the particles. Elemental concentration trends were determined as a function of size and temperature and the results compared to published reports for conventional power plants. The behavior of trace metals appears to be substantially different in the two systems due to lower operating temperatures and the addition of limestone to the fluidized bed. Corrosion of the impactor plates was observed at the highest temperature and lowest limestone feed rate sampled during the study. Data from the elemental concentration and leaching studies suggest that corrosion is most likely due to reactions involving sodium sulfate. However, it is concluded that corrosion is less of a potential problem in fluidized-bed systems than in conventional coal-fired systems.

Natusch, D.F.S.; Taylor, D.R.

1980-01-01

38

6- X 6-Ft Atmospheric Fluidized-Bed Combustion Development Facility and Commercial-Utility AFBC Design Assessment.  

National Technical Information Service (NTIS)

Atmospheric Fluidized-Bed Combustion (AFBC) is being developed by the Electric Power Research Institute and Babcock and Wilcox as a possible alternative to the conventional pulverized coal boiler equipped with a wet (or dry) scrubber. This program compris...

R. P. Apa J. M. Bloss P. L. Daniel

1983-01-01

39

Inclined fluidized bed system for drying fine coal  

DOEpatents

Coal is processed in an inclined fluidized bed dryer operated in a plug-flow manner with zonal temperature and composition control, and an inert fluidizing gas, such as carbon dioxide or combustion gas. Recycled carbon dioxide, which is used for drying, pyrolysis, quenching, and cooling, is produced by partial decarboxylation of the coal. The coal is heated sufficiently to mobilize coal tar by further pyrolysis, which seals micropores upon quenching. Further cooling with carbon dioxide enhances stabilization.

Cha, Chang Y. (Golden, CO); Merriam, Norman W. (Laramie, WY); Boysen, John E. (Laramie, WY)

1992-02-11

40

Nucla circulating atmospheric fluidized bed demonstration project. Final report  

SciTech Connect

Colorado-Ute Electric Association began a study to evaluate options for upgrading and extending the life of its Nucla power station in 1982. Located in southwestern Colorado near the town of Nucla, this station was commissioned in 1959 with a local bituminous coal as its design fuel for three identical stoker-fired units, each rated at 12.6 MW(e). Poor station efficiency, high fuel costs, and spiraling boiler maintenance costs forced the Nucla Station into low priority in the CUEA dispatch order as early as 1981. Among the options CUEA considered was to serve as a host utility to demonstrate Atmospheric Fluidized Bed Combustion (AFBC) technology. The anticipated environmental benefits and apparent attractive economics of a circulating AFBC led to Colorado-Ute`s decision to proceed with the design and construction of a demonstration project in 1984 at the Nucla facility.

Not Available

1991-10-01

41

Coal beneficiation and tribioelectric effects in a circulating fluidized bed  

Microsoft Academic Search

The purpose of the research was to investigate an alternative method of reducing the pyritic sulfur and ash content in finely ground coal be triboelectrically charging the particles in a circulating fluidized bed and then separating the particles in an electrostatic precipitator. The study also investigated the mechanisms by which glass particles acquire a charge in either the riser section

Tucholski

1992-01-01

42

Westinghouse Fluidized Bed Coal Gasification System: Experience and Plans.  

National Technical Information Service (NTIS)

A comprehensive program is underway to evaluate the Westinghouse fluidized bed coal gasification system for a combined cycle power plant. Such a plant is expected to be lower in capital costs, lower in pollutant emissions and have the potential for higher...

J. D. Holmgren L. A. Salvador

1978-01-01

43

AFBC (atmospheric fluidized bed combustion) conversion at Northern States Power Company  

Microsoft Academic Search

This document is the fourth volume in a series of four reports detailing the conversion of Northern States Power Company's Black Dog Unit 2 from pulverized coal-firing to atmospheric fluidized bed combustion (AFBC). This particular volume details the construction activities, organizations involved, responsibilities and overall scheduling of the conversion to AFBC from the mobilization of the boiler erection contractor to

Grieve

1990-01-01

44

Method for using fast fluidized bed dry bottom coal gasification  

DOEpatents

Carbonaceous solid material such as coal is gasified in a fast fluidized bed gasification system utilizing dual fluidized beds of hot char. The coal in particulate form is introduced along with oxygen-containing gas and steam into the fast fluidized bed gasification zone of a gasifier assembly wherein the upward superficial gas velocity exceeds about 5.0 ft/sec and temperature is 1500.degree.-1850.degree. F. The resulting effluent gas and substantial char are passed through a primary cyclone separator, from which char solids are returned to the fluidized bed. Gas from the primary cyclone separator is passed to a secondary cyclone separator, from which remaining fine char solids are returned through an injection nozzle together with additional steam and oxygen-containing gas to an oxidation zone located at the bottom of the gasifier, wherein the upward gas velocity ranges from about 3-15 ft/sec and is maintained at 1600.degree.-200.degree. F. temperature. This gasification arrangement provides for increased utilization of the secondary char material to produce higher overall carbon conversion and product yields in the process.

Snell, George J. (Fords, NJ); Kydd, Paul H. (Lawrenceville, NJ)

1983-01-01

45

Nucla circulating atmospheric fluidized bed demonstration project  

SciTech Connect

During the fourth quarter of 1990, steady-state performance testing at the Nucla Circulating Fluidized Bed (CFB) resumed under sponsorship of the US Department of Energy. Co-sponsorship of the Demonstration Test Program by the Electric Power Research Institute (EPRI) was completed on June 15, 1990. From October through December, 1990, Colorado-Ute Electric Association (CUEA) completed a total of 23 steady-state performance tests, 4 dynamic tests, and set operating records during November and December as the result of improved unit operating reliability. Highlight events and achievements during this period of operation are presented.

Not Available

1991-01-31

46

Characterization and use of fluidized-bed-combustion coal ash  

Microsoft Academic Search

Fluidized-bed-combustion (FBC) technology will become more common as coal-combustion systems are retrofitted to meet air-emissions standards mandated by the 1991 Clean Air Act. FBC ash will present new challenges for coal-combustion by-product management. Calcium-based sorbents added to the combustion system of FBC make the properties of the resulting ash different from electric-utility fly ash. Recycling options, used to divert electric-utility

C. B. Behr-Andres; N. J. Hutzler

2009-01-01

47

Radiative heat transfer in a circulating fluidized bed coal combustor  

Microsoft Academic Search

In order to investigate the contribution of radiative heat transfer to total heat transfer in a circulating fluidized bed coal combustor, heat transfer experiments were carried out. The test facility has the dimension of 6.0 m in height and 0.2 m×0.2 m rectangular cross-section. Anthracite coal was used for the fuel, and the heat transfer tubes were installed near the

Gui Young Han; Yong Jun Cho

1999-01-01

48

Pulverized coal vs. circulating fluidized bed; An economic comparison  

SciTech Connect

As the power industry looks to the 1990s for expanded steam generation capacity, boiler owners will continue on their long-standing assignment to evaluate and select the best, lowest cost alternative to meet their energy needs. For coal-fired plants, this evaluation process includes pulverized coal-fired boilers (PC) and circulating fluidized bed boilers (CFB). The cost difference between these products is site specific and depends on several variables, including: boiler size, pressure, and temperature; operating variables, such as the costs for fuel, auxiliary power, SO{sub 2} reagent, and ash disposal; capital cost; and financial variables, such as evaluation period and interest rate. This paper provides a technical and economic comparison between a pulverized coal-fired boiler and circulating fluidized bed boiler.

John, R.F. (Babcock and Wilcox Co., Barberton, OH (USA))

1989-01-01

49

Fluidized-bed bioreactor system for the microbial solubilization of coal  

DOEpatents

A fluidized-bed bioreactor system for the conversion of coal into microbially solubilized coal products. The fluidized-bed bioreactor continuously or periodically receives coal and bio-reactants and provides for the production of microbially solubilized coal products in an economical and efficient manner. An oxidation pretreatment process for rendering coal uniformly and more readily susceptible to microbial solubilization may be employed with the fluidized-bed bioreactor. 2 figs.

Scott, C.D.; Strandberg, G.W.

1987-09-14

50

Fluidized-bed bioreactor process for the microbial solubiliztion of coal  

DOEpatents

A fluidized-bed bioreactor system for the conversion of coal into microbially solubilized coal products. The fluidized-bed bioreactor continuously or periodically receives coal and bio-reactants and provides for the production of microbially solubilized coal products in an economical and efficient manner. An oxidation pretreatment process for rendering coal uniformly and more readily susceptible to microbial solubilization may be employed with the fluidized-bed bioreactor.

Scott, Charles D. (Oak Ridge, TN); Strandberg, Gerald W. (Farragut, TN)

1989-01-01

51

Fluidized-bed bioreactor process for the microbial solubilization of coal  

SciTech Connect

This patent describes a fluidized-bed bioreactor system for the conversion of coal into microbially solubilized coal products. The fluidized-bed bioreactor continuously or periodically receives coal and bio-reactants and provides for the production of microbially solubilized coal products in an economical and efficient manner. An oxidation pretreatment process for rendering coal uniformly and more readily susceptible to microbial solubilization may be employed with the fluidized-bed bioreactor.

Scott, C.D.; Strandberg, G.W.

1989-07-11

52

Modeling a fluidized-bed coal gasification reactor  

SciTech Connect

A steady-state model has been developed to simulate the North Carolina State University pilot-scale fluidized bed coal gasification reactor. The model involves instantaneous devolatilization of coal in the free-board region and char combustion and gasification in the fluidized bed. A two-phase representation of the fluidized bed incorporates the phenomena of jetting, bubbling, slugging, and mass and heat transfer between phases. The model has the ability to predict both concentration and temperature profiles, the latter being useful in the prediction of possible clinker formation at hot spots within the bed. The model has been successfully used to simulate the gasification of a devoltailized Western Kentucky bituminous coal and a New Mexico subbituminous coal. Effects of the molar steam/carbon feed ratio, molar oxygen/carbon feed ratio, fluidized bed height, and pressure on gasifer performance have been studied parametrically with the two-phase model. The molar steam/carbon feed ratio has moderate negative effects on the reactor performance. The approach to water-gas shift equilibrium is favored by lowering the steam/carbon ratio and/or raising oxygen/carbon ratio. The effects of moderate change sin bed height and pressure on the gasifier performance are small, implying that the reactor can be operated at any bed height and pressure near the targeted operating conditions without significantly affecting the gasifier output. Organic sulfur distributions in a New Mexico subbituminous coal and a Texas lignite have been determined by a nonisothermal technique. A three-stage well-mixed bed model incorporating the hydrodesulfurization kinetics of Yergey et al. was used to correlate the evolution rate of H{sub 2}S from coal or char during gasification.

Ma, R.P.

1987-01-01

53

Coal-fired CAES system using fluidized bed combustion  

SciTech Connect

Utility requirements for peaking power can be addressed with coal through the unique marriage of the compressed air energy storage and fluidized bed combustion technologies. This paper discusses the results of an evaluation of a pressurized fluidized bed combustion system at air storage pressures from 27 to 68 atm. A conceptual design of the PFBC configuration in a CAES system is presented. Major components of the system are identified as either state-of-the-art or requiring further R and D. The performance of the compressed air energy storage system with an efficiency of 83.4% (based on coal input energy) is presented. The effects of recovery of rejected heat are discussed also.

Moskowitz, S.; Schaeffer, R.

1983-11-01

54

(Pulsed atmospheric fluidized bed combustion (PAFBC)). [Comparing PAFBC vs. AFBC  

SciTech Connect

The fourth Quarterly Technical Progress Report presents the results of work accomplished during the period February 6 through April 30, 1989. the overall objective of the program is the development of a pulsed atmospheric, fluidized bed combustion (PAFBC) technology to burn coal and to provide heat and steam to commercial, institutional, and small industrial applications at a reasonable price in an environmentally acceptable manner. During this past quarter, a baseline for comparing PAFBC vs. AFBC performance was established and the initial series of PAFBC coal-fired combustion tests was completed. The AFBC baseline was representative of bubbling bed units with the exception of emissions which were somewhat higher and attributable to the size constraints of the AFBC unit. However, it still provided a valid baseline for referencing and optimizing PAFBC performance. Initial coal combustion tests in the pulsed fluid-bed verified enhanced performance in comparison to the non-pulsed beds, providing reduced NO{sub x}, CO, and SO{sub 2} emissions as well as higher steam generation rates and considerably lower entrainment losses. 9 figs., 4 tabs.

Not Available

1989-05-01

55

Clean coal fluidized-bed technology in Poland  

Microsoft Academic Search

The use of a circulating fluidized-bed (CFB) for power generation is a rapidly growing technology in Poland. The ability of CFBs to burn a wide variety of fuels, while meeting strict emission-control regulations, makes them an ideal choice for burning such fuels as high-sulfur coal, lignite, peat, oil, sludge, petroleum coke, gas and wastes. All these fuels are burned cleanly

W. Nowak

2003-01-01

56

Ash Vaporization in Circulating Fluidized Bed Coal Combustion  

Microsoft Academic Search

In this work, the vaporization of the ash forming constituents in circulating fluidized bed combustion (CFBC) in a full-scale 80 MWth unit was studied. Ash vaporization in CFBC was studied by measuring the fly ash aerosols in a full-scale boiler upstream of the electrostatic precipitator (ESP) at the flue gas temperature of 125°C. The fuel was a Venezuelan bituminous coal,

Terttaliisa Lind; Esko I. Kauppinen; Willy Maenhaut; Anup Shah; Frank Huggins

1996-01-01

57

Desulfurization in reducing atmosphere and ammonia injection denitrification in a coal-fired fluidized bed combustor with fly-ash recycle  

NASA Astrophysics Data System (ADS)

With the rising of IGCC and the second generation PFBC-CC, and with the development of technology of staged combustion to lower emission of NOx, the desulfurization efficiency under reducing atmosphere is raised. In this paper, with the application of the fly-ash recycle and two-stage combustion technologies in a fluidized bed combustor, the desulfurization test under reducing atmosphere is described. Meanwhile, ammonia injection test was also conducted. Results show that desulfurization under reducing atmosphere has higher efficiency, and ammonia injection denitrification effect is very perfect.

Zhong, Zhaoping; Lan, Jixiang; Han, Yongsheng; Wu, Xin; Zheng, Haiyun

1997-03-01

58

Heat exchanger materials for fluidized-bed coal combustion  

SciTech Connect

The objective of this study was to determine the corrosion performance of heat exchanger and uncooled internal structural materials in atmospheric fluidized-bed combustors (AFBCs). Although crushed limestone is used in the fluidized bed as a sulfur absorber, it is known that both oxidation and sulfidation of in-bed components occurs in beds that operate at temperatures of 500 to 870/sup 0/C. Accordingly, these studies were conducted to estimate the service lifetimes of AFBC candidate alloys under prototypic AFBC conditions. The candidate materials included chromium-molybdenum steels and stainless steel-304. The results are intended to guide the selection of materials of construction for demonstration AFBCs anticipated in the early 1980s.

Devan, J.H.; Godfrey, T.G.; Ficalora, P.J.

1981-01-01

59

Characterization of fuels for atmospheric fluidized bed combustion  

SciTech Connect

The Electric Power Research Institute (EPRI) has sponsored a fuels characterization program for the past several years with the intention of assisting utilities and boiler manufacturers in evaluating fuel quality impact on atmospheric fluidized bed combustion (AFBC) performance. The goal has been to provide an improved framework for making fuel switching decisions and consolidating operating experience. Results from this program include a set of bench-scale testing procedures, a fuel characterization data base, and a performance simulation model that links fuel characteristics to combustion performance. This paper reviews the major results of the fuels characterization program. The testing procedures, data base, and performance simulation models are briefly described and their application illustrated with examples. Performance predictions for the B W 1-ft{sup 2} bench-scale AFBC and the Tennessee Valley Authority (TVA) 20 MW(e) AFBC Pilot Plant are compared with actual test data. The relationship of coal rank to combustion is discussed. 11 refs., 12 figs., 5 tabs.

Daw, C.S. (Oak Ridge National Lab., TN (USA)); Rowley, D.R.; Perna, M.A. (Babcock and Wilcox Co., Alliance, OH (USA). Research Center); Stallings, J.W. (Electric Power Research Inst., Palo Alto, CA (USA)); Divilio, R.J. (Combustion Systems, Inc., Silver Spring, MD (USA))

1990-01-01

60

NUCLA Circulating Atmospheric Fluidized Bed Demonstration Project. Annual report, 1988  

SciTech Connect

This Annual Report on Colorado-Ute Electric Association`s NUCLA Circulating Fluidized Bed (CFB) Demonstration Program covers the period from February 1987 through December 1988. The outline for presentation in this report includes a summary of unit operations along with individual sections covering progress in study plan areas that commenced during this reporting period. These include cold-mode shakedown and calibration, plant commercial performance statistics, unit start-up (cold), coal and limestone preparation and handling, ash handling system performance and operating experience, tubular air heater, baghouse operation and performance, materials monitoring, and reliability monitoring. During this reporting period, the coal-mode shakedown and calibration plan was completed. (VC)

Not Available

1991-01-01

61

Potential health and environmental effects of the fluidized-bed combustion of coal  

Microsoft Academic Search

A summary of the potential health and environmental effects of burning coal by fluidized bed combustion is presented. An increased use of coal combustion as a whole, an increasing fraction of which may be burned at the low temperature of fluidized bed combustors (FBC), is causing concern about potential health and environmental effects. The following concerns, in particular, are addressed:

F. A. Seiler; C. H. Hobbs; R. G. Cuddihy

1982-01-01

62

Coal gasification characteristics in an internally circulating fluidized bed with draught tube  

Microsoft Academic Search

Australian coal was gasified at atmospheric pressure in an internally circulating fluidized bed (0.3 m i.d. × 2.7 m high) with a draught tube (0.1 m i.d. × 0.9 m high) and a gas separator over the draught tube. The effects of reaction temperature (780–900°C), oxygen\\/coal mass ratio (0.30–0.53), coal feed rate (5.3–12.1 kg h?1) and steam\\/coal mass ratio (0.30–0.81)

Yong Jeon Kim; Jong Min Lee; Sang Done Kim

1997-01-01

63

NUCLA Circulating Atmospheric Fluidized Bed Demonstration Project  

SciTech Connect

The report summarizes unit operating experience and test program progress for 1989 on Colorado-Ute Electric Association's Nucla CFB Demonstration Program. During this period, the objectives of the Nucla Station operating group were to correct problems with refractory durability, resolve primary air fan capacity limitations, complete the high ash and high sulfur coal tests, switch to Salt Creek coal as the operating fuel, and make the unit available for testing without capacity restrictions. Each of these objectives was addressed and accomplished, to varying degrees, except for the completion of the high sulfur coal acceptance tests. (VC)

Not Available

1992-02-01

64

Effects of Particle Size, Shape, and Density on the Performance of an Air Fluidized Bed in Dry Coal Beneficiation  

Microsoft Academic Search

We consider here the implementation of dry coal beneficiation using air fluidized bed technology. Although the applications of the fluidized bed dry coal separator have been done successfully on an industrial scale in the past, the process has been characterized by relatively poor Ep values. In this study, a 40 × 40 × 60 cm dry batch air fluidized bed coal separator with a relatively

Pheneas Chikerema; Michael Moys

2012-01-01

65

Experience with atmospheric fluidized bed gasification of switchgrass  

SciTech Connect

Switchgrass was gasified in a bubbling fluidized bed reactor rated at 800 kW (2.75 MMBtu/hr) thermal input and operating at atmospheric pressure. A combustible gas with higher heating value varying between 4.2--5.9 MJ/Nm{sup 3} (114--160 Btu/scf) was produced. Carbon conversion was approximately 85%. Difficulties in feeding high moisture switchgrass inhibited smooth reactor operation. Several feed systems for switchgrass were tried with varying degrees of success. The results of gasification trials using switchgrass as fuel are described.

Smeenk, J.; Brown, R.C. [Iowa State Univ., Ames, IA (United States). Center for Coal and the Environment

1998-12-31

66

Hydrodynamic behavior of a liquid-solid fluidized-bed reactor for the bioconversion of coal particles to liquid products.  

National Technical Information Service (NTIS)

A predictive mathematical model based on particle convection and dispersion is presented for a liquid fluidized bed of coal particles. The numerical representation can follow transient behavior of liquid fluidized beds that contain a defined particle-size...

T. C. Scott E. N. Kaufman J. M. Cosgrove M. Asif J. N. Petersen

1993-01-01

67

Technical notes for the conceptual design for an atmospheric fluidized-bed direct combustion power generating plant. [570 MWe plant  

SciTech Connect

The design, arrangement, thermodynamics, and economics of a 578 MW(e) (nominal gross) electric power generating plant equipped with a Foster Wheeler Energy Corporation (FWEC) atmospheric fluidized bed (AFB) boiler are described. Information is included on capital and operating costs, process systems, electrical systems, control and instrumentation, and environmental systems. This document represents a portion of an overall report describing the conceptual designs of two atmospheric fluidized bed boilers and balance of plants for the generation of electric power and the analysis and comparison of these conceptual designs to a conventional pulverized coal-fired electric power generation plant equipped with a wet limestone flue gas desulfurization system.

None

1978-04-01

68

Coal-gasification kinetics derived from pyrolysis in a fluidized-bed reactor  

Microsoft Academic Search

Coal pyrolysis and gasification reactions were carried out in a fluidized-bed reactor (0.1m i.d. by 1.6m height) over a temperature range from 1023 to 1173K at atmospheric pressure. The overall gasification kinetics for the steam–char and oxygen–char reactions were determined in a thermobalance reactor. The compositions of the product gases from the coal-gasification reactions are 30–40% H2, 23–28% CO, 27–35%

Jong Min Lee; Yong Jeon Kim; Woon Jae Lee; Sang Done Kim

1998-01-01

69

ENVIRONMENTAL ASSESSMENT: SOURCE TEST AND EVALUATION REPORT - B AND W/ALLIANCE ATMOSPHERIC FLUIDIZED-BED COMBUSTOR  

EPA Science Inventory

The report gives results of a comprehensive emission sampling and analysis of a pilot-scale, atmospheric-pressure, coal-fired, fluidized-bed combustor (AFBC). Screening data on organic and inorganic pollutants and indications of biological activity were obtained. The Babcock and ...

70

Particulate control experience after fluidized bed boilers firing coal  

Microsoft Academic Search

The energy crisis resulted in an intensified development of the fluidized bed boiler. In 1983, ten years later there are in the western world more than 100 units in operation or under construction. Manufacturers can offer designs with slow (bubbling) or fast (circulating) beds supported by more or less extensive experience. The fluidized bed combustor (FBC) has many advantages claimed

S. Maartmann; J. Kreminski

1983-01-01

71

Identification of Regenerable Metal Oxide SO2 Sorbents for Fluidized-Bed Coal Combustion.  

National Technical Information Service (NTIS)

The report briefly summarizes results of an analysis to identify regenerable metal oxide SO2 sorbents for fluidized-bed coal combustion. It recommends continued investigation. It discusses both the approach used for the theoretical study of sorption/regen...

P. S. Lowell T. B. Parsons

1975-01-01

72

Atmospheric fluidized bed combustion advanced system concepts applicable to small industrial and commercial markets.  

National Technical Information Service (NTIS)

Under a contract with Morgantown Energy Technology Center (METC), Riley Stoker Corporation (Riley) has developed designs and cost estimates for two coal-fired systems using Riley's Multi Solid Fluidized Bed (MSFB) concept. One is a package unit designed f...

V. B. Dixit R. K. Mongeon

1990-01-01

73

Release of nitrogen precursors from coal and biomass residues in a bubbling fluidized bed  

SciTech Connect

This work was undertaken with the aim of quantifying the relative amounts of NH{sub 3} and HCN released from different residues during their devolatilization under fluidized bed conditions. The results were compared with data collected for bituminous coals of different origin. The relation between amounts of HCN and NH{sub 3} released and the levels of NOX and N{sub 2}O formed during cocombustion was also addressed. The partitioning of nitrogen between volatiles and char was also quantified. The pyrolysis studies were undertaken in a small fluidized bed reactor of 80 mm of ID and 500 mm high using an inert atmosphere (N{sub 2}). The HCN and NH{sub 3} were quantified by bubbling the pyrolysis gases in absorbing solutions which were subsequently analyzed with selective electrodes. The combustion studies were carried out on a pilot installation. The fluidized bed combustor is square in cross section with each side being 300 mm long. There is secondary air supply to the freeboard at different heights to deal with high volatile fuels as almost all waste materials are. The temperatures in the bed and in the freeboard and that of the flue gases leaving the reactor were continuously monitored. The results obtained suggest that, while coal releases nitrogen mostly as HCN, residues like RDF and sewage sludge give out fuel-N in greater quantities as NH{sub 3}. Residues at fluidized bed combustion (FBC) temperatures release more than 80% of the fuel-N with the volatiles. The NH{sub 3} evolved during pyrolysis acted as a reducing agent on NOX emissions. The presence of calcium significantly reduces the emission of N{sub 2}O probably by interfering with HCN chemistry. With high amounts of residues in the fuel mixture, the relative importance of char on the nitrogen chemistry substantially decreases. By using cocombustion, it is possible to reduce fuel-N conversion to NOX and N{sub 2}O, by tuning the amounts of coal and residue in the mixture. 29 refs., 18 figs., 3 tabs.

P. Abelha; I. Gulyurtlu; I. Cabrita [Instituto Nacional de Engenharia, Lisbon (Portugal)

2008-01-15

74

Industrial steam-supply-system characteristics program. Phase 1. Conventional boilers and atmospheric-fluidized-bed combustor. Final report  

SciTech Connect

Foster Wheeler Development Corporation (FWDC), has developed conceptual plant designs, engineering characteristics, operating requirements, and cost estimates for various industrial steam supply systems with alternate emission standards. The program encompassed the design and costing of four steam generator systems - pulverized coal-fired, spreader stoker coal-fired, oil-fired, and atmospheric fluidized bed coal-fired - with their respective auxiliary equipment and a comparison of the more practical emission control processes for each system. The work done under Phase 1 - Conventional Boilers and Atmospheric Fluidized Bed Combustor of ORNL's Industrial Steam Supply System Characteristics Program, is summarized in this volume. Realistic plant designs for the steam generator systems studied and cost estimates were developed on a comparable and consistent basis. The results of Phase 2 - Low and Medium Btu Gas-Fired Boilers with Associated Gasification Plants is summarized.

Not Available

1981-08-15

75

Atmospheric fluidized bed combustion for small scale market sectors. Final report  

SciTech Connect

The objective of this project was to demonstrate and promote the commercialization of coal-fired atmospheric fluidized bed combustion (AFBC) systems, with limestone addition for SO{sub 2} emissions control and a baghouse for particulate emissions control. This AFBC system was targeted for small scale industrial-commercial-institutional space and process heat applications. A cost effective and environmentally acceptable AFBC technology in this size range would displace a considerable amount of gas/oil with coal while resulting in significant total cost savings to the owner/operators. In the Proof-of-Concept Phase, a 2.2 x 10{sup 6} Btu/hr unit was installed and successfully operated at Cedar Lane Farms (CLF), a commercial nursery in Ohio. The heat from the fluidized bed was used to heat hot water which was recirculated through greenhouses for cool weather heating. The system was designed to be fully automated with minimal operator attention required. The AFBC system installed at CLF was an improved design that incorporated flyash/sorbent reinjection and an underbed feed system to improve limestone utilization. With these additions it was possible to lower the Ca/S ratio from {approximately} 3.0 to 2.0, and still maintain an SO{sub 2} emissions level of 1.2 lb/10{sup 6} Btu when burning the same high sulfur Ohio coal tested at OARDC.

Ashworth, R.A.; Plessinger, D.A.; Sommer, T.M. [Energy and Environmental Research Corp., Orville, OH (United States); Keener, H.M. [Ohio Agricultural Research and Development Center, OH (United States); Webner, R.L. [Will-Burt Co., Orrville, OH (United States)

1997-03-31

76

Heat transfer to horizontal tubes in a pilot-scale fluidized-bed combustor burning low-rank coals  

Microsoft Academic Search

Experimental data are obtained for the heat transfer coefficient between immersed horizontal tube bundles and an atmospheric-fluidized-bed combustor burning low-rank coals. Silica sand (d\\/sub p\\/ = 888 to 1484 ..mu..m) and limestone (d\\/sub p\\/ = 716 to 1895 ..mu..m) are used as bed material. The tests are conducted, with and without limestone addition and ash recycle, at average bed temperatures

N. S. Grewal; G. Goblirsch

1983-01-01

77

Heat transfer to horizontal tubes in a pilot-scale fluidized-bed combustor burning low-rank coals  

Microsoft Academic Search

Experimental data are obtained for the heat transfer coefficient between immersed horizontal tube bundles and an atmospheric-fluidized-bed combustor burning low-rank coals. Silica sand and limestone are used as bed material. The tests are conducted, with and without limestone addition and ash recycle, at average bed temperatures ranging from 1047 to 1125 K, superficial fluidizing velocity of 1.66 to 2.04 m\\/s,

N. S. Grewal; G. Goblirsch

1983-01-01

78

HEAT TRANSFER TO HORIZONTAL TUBES IN A PILOT-SCALE FLUIDIZED-BED COMBUSTOR BURNING LOW-RANK COALS  

Microsoft Academic Search

Experimental data are obtained for the heat transfer coefficient between immersed horiziontal tube bundles and an atmospheric-fluidized-bed combustor burning low-rank coals. Silica sand (dp = 888 to 1484 ?m) and limestone (dp 7= 716 to 1895 ?m) are used as bed material. The tests are conducted, with and without limestone addition and ash recycle, at average bed temperatures ranging from 1047 to

N. S. GREWAL; E. S. SORENSON; G. GOBLIRSCH

1985-01-01

79

Low Density Dry Coal Beneficiation Using an Air Dense Medium Fluidized Bed  

Microsoft Academic Search

For the production of low ash content clean coal, separation at low density is required for some raw coals. Based on analyzing the fluidizing characteristics of magnetic pearls with a specific size distribution and formation mechanism of a microbubble fluidized bed, optimal technological and operating parameters suitable for low density coal separation were determined. The experimental results show that an

Zhen-fu LUO; Jian-feng ZHU; Mao-ming FAN; Yue-min ZHAO; Xiu-xiang TAO

2007-01-01

80

JV Task 108 - Circulating Fluidized-Bed Combustion and Combustion Testing of Turkish Tufanbeyli Coal  

Microsoft Academic Search

Two combustion tests were performed at the Energy & Environmental Research Center (EERC) using Tufanbeyli coal from Turkey. The tests were performed in a circulating fluidized-bed combustor (CFBC) and a pulverized coal-fired furnace, referred to as the combustion test facility (CTF). One of the goals of the project was to determine the type of furnace best suited to this coal.

Douglas Hajicek; Jay Gunderson; Ann Henderson; Stephen Sollom; Joshua Stanislowski

2007-01-01

81

MINIPLANT STUDIES OF PRESSURIZED FLUIDIZED-BED COAL COMBUSTION: THIRD ANNUAL REPORT  

EPA Science Inventory

The report presents further results of studies of the environmental aspects of the pressurized fluidized-bed coal combustion process, using the 218 kg coal/hr 'miniplant' continuous-combustion/sorbent-regeneration system (0.63 MW equivalent), and a 13 kg coal/hr bench-scale syste...

82

SUPPORT STUDIES IN FLUIDIZED-BED COMBUSTION  

EPA Science Inventory

The report gives results of working in support of development studies for atmospheric and pressurized fluidized-bed coal combustion. Laboratory and process development studies are aimed at providing needed information on limestone utilization, removal of particulates and alkali m...

83

SUPPORTIVE STUDIES IN FLUIDIZED-BED COMBUSTION  

EPA Science Inventory

The report gives results of studies supporting the development of atmospheric and pressurized fluidized-bed combustion (FBC) of coal. It includes laboratory and bench-scale studies to provide needed information on combustion optimization, regeneration process development, solid w...

84

Fluidized-bed combustion  

SciTech Connect

This report describes the activities of the Morgantown Energy Technology Center's research and development program in fluidized-bed combustion from October 1, 1987, to September 30, 1989. The Department of Energy program involves atmospheric and pressurized systems. Demonstrations of industrial-scale atmospheric systems are being completed, and smaller boilers are being explored. These systems include vortex, multi-solid, spouted, dual-sided, air-cooled, pulsed, and waste-fired fluidized-beds. Combustion of low-rank coal, components, and erosion are being studied. In pressurized combustion, first-generation, combined-cycle power plants are being tested, and second-generation, advanced-cycle systems are being designed and cost evaluated. Research in coal devolatilization, metal wastage, tube corrosion, and fluidization also supports this area. 52 refs., 24 figs., 3 tabs.

Botros, P E

1990-04-01

85

AFBC (atmospheric fluidized bed combustion) conversion at Northern States Power Company  

SciTech Connect

This document is the fourth volume in a series of four reports detailing the conversion of Northern States Power Company's Black Dog Unit 2 from pulverized coal-firing to atmospheric fluidized bed combustion (AFBC). This particular volume details the construction activities, organizations involved, responsibilities and overall scheduling of the conversion to AFBC from the mobilization of the boiler erection contractor to the beginning of the startup phase. The purpose of these reports is to share the information gathered during the Black Dog AFBC Conversion Project and present it so that other utilities can evaluate the technical feasibility and cost effectiveness of converting units within their systems from pulverized coal-firing to AFBC. To this end, each volume in this series of reports presents material concerning a different aspect of the Black Dog project. 18 figs., 15 tabs.

Grieve, R. (Stone and Webster Engineering Corp., Boston, MA (USA))

1990-01-01

86

Effect of limestone on ash behavior in fluidized-bed gasification of coal.  

National Technical Information Service (NTIS)

The behavior of coal mineral matter is of interest in fluidized-bed coal gasification and stage combustion because it governs the formation of ash agglomerates that facilitate ash removal from the reactor without excessive loss of carbon as well as deposi...

S. D. Kline D. M. Mason R. H. Carty S. P. Babu

1989-01-01

87

Design of a 165 MWe reheat coal-fired circulating fluidized bed boiler for Nova Scotia Power Corporation  

Microsoft Academic Search

In October 1989, a contract was awarded to Pyropower Corporation for the design, supply and erection of the 165 MW{sub e} reheat coal fired circulating fluidized bed boiler for the Point Aconi site in Nova Scotia, Canada. This order represented the largest capacity circulating fluidized bed (CFB) boiler sold to date. This paper presents the boiler design parameters, design arrangement

B. Schaller; J. Darguzas; S. Fraser

1990-01-01

88

A model of coal particle drying in fluidized bed combustion reactor  

SciTech Connect

Experimental and theoretical investigation on drying of a single coal particle in fluidized bed combustor is presented. Coal particle drying was considered via the moist shrinking core mechanism. The results of the drying test runs of low-rank Serbian coals were used for experimental verification of the model. The temperature of the coal particle center was measured, assuming that drying was completed when the temperature equalled 100{sup o}C. The influence of different parameters (thermal conductivity and specific heat capacity of coal, fluidized bed temperature, moisture content and superheating of steam) on drying time and temperature profile within the coal particle was analyzed by a parametric analysis. The experimentally obtained results confirmed that the moist shrinking core mechanism can be applied for the mathematical description of a coal particle drying, while dependence between drying time and coal particle radius, a square law relationship, implicates heat transfer control of the process and confirms the validity of assumptions used in modeling.

Komatina, M.; Manovic, V.; Saljnikov, A. [Natural Resources Canada, Ottawa, ON (Canada). CANMET, Energy Technology Centre

2007-02-15

89

Fluidized-bed catalytic coal-gasification process. [US patent; pretreatment to minimize agglomeration  

DOEpatents

Coal or similar carbonaceous solids impregnated with gasification catalyst constituents are oxidized by contact with a gas containing between 2 vol % and 21 vol % oxygen at a temperature between 50 and 250/sup 0/C in an oxidation zone and the resultant oxidized, catalyst impregnated solids are then gasified in a fluidized bed gasification zone at an elevated pressure. The oxidation of the catalyst impregnated solids under these conditions insures that the bed density in the fluidized bed gasification zone will be relatively high even though the solids are gasified at elevated pressure and temperature.

Euker, C.A. Jr.; Wesselhoft, R.D.; Dunkleman, J.J.; Aquino, D.C.; Gouker, T.R.

1981-09-14

90

Steam-activated carbons from a bituminous coal in a continuous multistage fluidized bed pilot plant  

Microsoft Academic Search

A vertical three-stage fluidized bed pilot plant, with downcomers, was designed and built in order to study the continuous process of the production of activated carbons from a high-volatile bituminous coal from the Puertollano basin (Spain), by steam activation. The pilot plant can operate with a production of up to 40 kg per day. Very good activated carbons were produced

I. Martín-Gullón; M. Asensio; A. Marcilla

1996-01-01

91

ENVIRONMENTAL ASSESSMENT OF THE FLUIDIZED-BED COMBUSTION OF COAL: METHODOLOGY AND INITIAL RESULTS  

EPA Science Inventory

The paper discusses a program being conducted by the U.S. Environmental Protection Agency (EPA), aimed at complete environmental assessment (EA) of the fluidized-bed combustion (FBC) of coal. It reviews the EA methodology being developed by EPA: identification of current technolo...

92

FIRST TRIALS OF CHEMICALLY ACTIVE FLUIDIZED-BED (CAFB) PILOT PLANT ON COAL  

EPA Science Inventory

The report gives results of a minirun, carried out on a 0.75-MWe continuous, chemically active fluidized-bed (CAFB) pilot plant during July-August 1976, as part of a program to extend the CAFB process to operate on coal. After 8.5 hours of gasification on Texas lignite and Illino...

93

PRELIMINARY ENVIRONMENTAL ASSESSMENT OF COAL-FIRED FLUIDIZED-BED COMBUSTION SYSTEMS  

EPA Science Inventory

The report evaluates potential pollutants which could be generated in coal-fired fluidized-bed combustion (FBC) processes. The primary emphasis is on organic compounds, trace elements, inorganic compounds (other than SO2 and Nox), and particulates. Using available bench scale or ...

94

Factors affecting cleanup of exhaust gases from a pressurized, fluidized-bed coal combustor  

NASA Technical Reports Server (NTRS)

The cleanup of effluent gases from the fluidized-bed combustion of coal is examined. Testing conditions include the type and feed rate of the coal and the sulfur sorbent, the coal-sorbent ratio, the coal-combustion air ratio, the depth of the reactor fluidizing bed, and the technique used to physically remove fly ash from the reactor effluent gases. Tests reveal that the particulate loading matter in the effluent gases is a function not only of the reactor-bed surface gas velocity, but also of the type of coal being burnt and the time the bed is operating. At least 95 percent of the fly ash particules in the effluent gas are removed by using a gas-solids separator under controlled operating conditions. Gaseous pollutants in the effluent (nitrogen and sulfur oxides) are held within the proposed Federal limits by controlling the reactor operating conditions and the type and quantity of sorbent material.

Rollbuhler, R. J.; Kobak, J. A.

1980-01-01

95

Atmospheric fluidized bed combustion (AFBC) plants: an operations and maintenance study  

SciTech Connect

The authors analyzed data from a fluidized bed boiler survey distributed during the spring of 2003 to develop appropriate AFBC (Atmospheric Fluidized Bed Combustion) performance benchmarks. The survey was sent to members of CIBO (Council of Industrial Boiler Owners), who sponsored the survey, as well as to other firms who had an operating AFBC boiler on-site. There were three primary purposes for the collection and analysis of the data contained in this fluidized bed boiler survey: (1) To develop AFBC benchmarks on technical, cost, revenue, and environmental issues; (2) to inform AFBC owners and operators of contemporary concerns and issues in the industry; (3) to improve decision making in the industry with respect to current and future plant start-ups and ongoing operations.

Jack A. Fuller; Harvie Beavers; Robert Bessette [West Virginia University, Morgantown, WV (United States). College of Business and Economics

2006-06-15

96

Pilot plant of a coal fired fluidized bed boiler in Japan  

SciTech Connect

A pilot plant of an atmosphere fluidized bed combustion boiler which is capable of evaporating 20 t/h at the steam conditions of 60 atg and 540/sup 0/C was constructed and started operation at the beginning of April, 1981. A description of the project and its results are presented.

Tamanuki, S. (Coal Mining Research Center, Tokyo, Japan); Karayama, H.; Kawada, S.

1982-01-01

97

Pulsed atmospheric fluidized bed combustion. Technical progress report, January 1992--March 1992  

SciTech Connect

During this first quarter, a lab-scale water-cooled pulse combustor was designed, fabricated, and integrated with old pilot-scale PAFBC test systems. Characterization tests on this pulse combustor firing different kinds of fuel -- natural gas, pulverized coal and fine coal -- were conducted (without fluidized bed operation) for the purpose of finalizing PAFBC full-scale design. Steady-state tests were performed. Heat transfer performance and combustion efficiency of a coal-fired pulse combustor were evaluated.

Not Available

1992-05-01

98

Mild gasification of Usibelli coal in an inclined fluidized-bed reactor  

SciTech Connect

Results of mild gasification tests of minus 16-mesh Usibelli coal in an inclined fluidized-bed reactor are described in this report. The minus 16-mesh fraction was separated from the coal by screening. The coal was dried to zero moisture content, and about 2 wt % of the volatiles was removed as gas by partial decarboxylation using a 100-lb/hr inclined fluidized-bed dryer. The dried coal was subjected to mild gasification at maximum temperatures of 1050 to 1250{degrees}F (566 to 677{degrees}C) and feed rates of 7.5 lb/hr while using a once-through flow of carbon dioxide as fluidizing gas in a 1-inch-wide, inclined fluidized-bed reactor. Mild gasification of the dried coal resulted in production of 44 to 56 wt % of the dried coal as char, 10 to 13 wt % as liquids, 17 to 28 wt % as gas, and 8 to 21 wt % as fines. The yield of moisture- and ash-free (MAF) liquids varied from 11.4 to 14.2 wt % of the dried coal feed. Chemical analysis was carried out on these products.

Merriam, N.W.; Thomas, K.P.; Cha, C.Y.

1991-02-01

99

CONTROL OF PARTICULATE EMISSIONS FROM ATMOSPHERIC FLUIDIZED-BED COMBUSTION WITH FABRIC FILTERS AND ELECTROSTATIC PRECIPITATORS  

EPA Science Inventory

The report gives results of a study of chemical and physical characteristics affecting the performance of particulate control equipment, based on five fly ash samples from full- and pilot-scale atmospheric fluidized-bed combustion (AFBC) units. Analysis of acquired data by fabric...

100

Atmospheric fluidized-bed combustion waste utilization in cement and sulfuric acid: Preliminary feasibility study  

Microsoft Academic Search

An OACD interdisciplinary project team has investigated the preliminary feasibility of using atmospheric fluidized-bed combustion (AFBC) waste in the production of portland cement and sulfuric acid. This investigation found that it is technically and economically feasible to simultaneously produce electricity, portland cement, and sulfuric acid in an environmentally clean, integrated industrial complex. This complex would include a 500-MW AFBC unit

D. G. Salladay; D. E. Nichols; J. T. Berry; D. B. Call; E. A. Harre; Y. K. Kim

1986-01-01

101

An Experimental Investigation into the Fragmentation of Coal Particles in a Fluidized-Bed Combustor  

Microsoft Academic Search

\\u000a The fragmentation of coal plays a significant role in combustion in fluidized-bed boilers because it accelerates combustion\\u000a and influences the distribution of particle sizes in the bed. Fine char particles produced by comminution can be carried out\\u000a and increase the heat loss due to incomplete carbon conversion. The thermal fragmentation depends on the initial structure\\u000a of the coal and how

Monika Kosowska-Galacbowska; Adam Luckos

2010-01-01

102

Fluidized bed retrofit study on Consolidated Edison Arthur Kill No. 3 Generating Station. Step II. Conceptual boiler design  

Microsoft Academic Search

The objective of this project was to study the feasibility of retrofitting an existing utility boiler to fire coal utilizing atmospheric fluidized bed combustion and to estimate the cost of a fluidized bed retrofit. The unit selected for the retrofit study was Consolidated Edison's 500 Mw Arthur Kill Unit No. 3. The fluidized bed design parameters were based on those

R. B. Covell; S. L. Darling; M. C. Tanca

1978-01-01

103

[Pulsed atmospheric fluidized bed combustion (PAFBC)]. Technical progress report, February 1989--April 1989  

SciTech Connect

The fourth Quarterly Technical Progress Report presents the results of work accomplished during the period February 6 through April 30, 1989. the overall objective of the program is the development of a pulsed atmospheric, fluidized bed combustion (PAFBC) technology to burn coal and to provide heat and steam to commercial, institutional, and small industrial applications at a reasonable price in an environmentally acceptable manner. During this past quarter, a baseline for comparing PAFBC vs. AFBC performance was established and the initial series of PAFBC coal-fired combustion tests was completed. The AFBC baseline was representative of bubbling bed units with the exception of emissions which were somewhat higher and attributable to the size constraints of the AFBC unit. However, it still provided a valid baseline for referencing and optimizing PAFBC performance. Initial coal combustion tests in the pulsed fluid-bed verified enhanced performance in comparison to the non-pulsed beds, providing reduced NO{sub x}, CO, and SO{sub 2} emissions as well as higher steam generation rates and considerably lower entrainment losses. 9 figs., 4 tabs.

Not Available

1989-05-01

104

Metal emissions from co-combustion of sewage sludge and coal\\/wood in fluidized bed  

Microsoft Academic Search

Co-combustion of sewage sludge with coal or wood has been investigated in the 12MWth circulating fluidized bed (CFB) boiler at Chalmers Technical University. The investigation focuses on emissions of trace metals from co-combustion compared to mono-combustion in CFB. The results show that co-combustion can be carried out in a CFB plant designed for the base fuel without exceeding EU emission

L.-E. Åmand; B. Leckner

2004-01-01

105

The study of partitioning of heavy metals during fluidized bed combustion of sewage sludge and coal  

Microsoft Academic Search

The behavior of Cd, Cr, Cu, Co, Mn, Ni, Pb, Zn, and Hg during the combustion tests of a dry granular sewage sludge on a fluidized bed combustor pilot (FBC) of about 0.3 MW was evaluated. The emissions of these heavy metals from mono-combustion were compared with those of co-combustion of the sludge with a bituminous coal. The effect of

I. Gulyurtlu; M. Helena Lopes; P. Abelha; I. Cabrita; J. F. Santos Oliveira

2006-01-01

106

Effect of pressure fluctuation on coal combustion in large-particle fluidized beds  

SciTech Connect

Atmospheric fluidized-bed combustors (AFBC) operate in the large-particle (>1 mm) fluidization regime. Characteristics of this regime, combined with the fact that as much as 50% of the coal combustibles are volatiles, result in localization of the devolatilization and combustion of the volatilized gases to the neighborhood of the coal-particle and volatile gas plumes arising from the injector region. The volatile gas plume resulting from the large-particle fluidization dynamics wanders due to pressure fluctuations induced by bubble passage. The purpose of the present work is to determine the impact of these characteristics on the design of AFBC's. This has been accomplished by a linearized analysis of the governing equations to describe the periodic wandering of the volatiles plume diffusion flame and the corresponding fluctuation of the combustion rate. The flame oscillation increases the overall combustion rate above the steady-state value. This increase diminishes with increasing fluctuation frequency until the flame becomes insensitive to the fluctuation in the high frequency limit.

Bywater, R.J.; Chung, P.M.

1983-05-01

107

Planning, Construction and Operation of the 35 Mw sub TH-Test Facility Flingern for Firing Bituminous Coal in an Atmospheric Fluidized Bed Furnace.  

National Technical Information Service (NTIS)

Clean combustion of high ash and high sulfur coal with the boiler, retrofitted from traveling grate stoker to FBC was demonstrated. Within 4,200 operating hours 14,500 t of bituminous coal ranking from high grade to low grade were fired, generating 105,00...

H. G. Krischke R. W. Chalupnik H. P. Masuch

1982-01-01

108

Fabric filter testing at the TVA Atmospheric Fluidized-bed Combustion (AFBC) Pilot Plant  

Microsoft Academic Search

Experience with fluidized bed combustion (FBC) units on a research and industrial scale has indicated that FBC power plants could be a viable alternative to pulverized-coal power plants with wet limestone scrubbers or spray dryers. To provide design confidence and the flexibility to evaluate process improvements, the Tennessee Valley Authority constructed a 20-MW(e) AFBC (bubbling bed) Pilot Plant. Subseqently, EPRI

K. M. Cushing; P. V. Bush; T. R. Snyder

1988-01-01

109

Fluidized bed boiler feed system  

DOEpatents

A fluidized bed boiler feed system for the combustion of pulverized coal. Coal is first screened to separate large from small particles. Large particles of coal are fed directly to the top of the fluidized bed while fine particles are first mixed with recycled char, preheated, and then fed into the interior of the fluidized bed to promote char burnout and to avoid elutriation and carryover.

Jones, Brian C. (Windsor, CT) [Windsor, CT

1981-01-01

110

Emissions from FBC (Fluidized-Bed Combustion) Boilers.  

National Technical Information Service (NTIS)

The paper provides perspective regarding the environmental acceptability of atmospheric-pressure fluidized-bed boilers, with particular emphasis on the application of this technology as a technique for utilizing coal in the industrial sector. It reviews e...

D. B. Henschel

1978-01-01

111

Modularized dry coal beneficiation technique based on gas-solid fluidized bed  

Microsoft Academic Search

A 40–60 t\\/h modularized dry coal beneficiation process with a novel method to control the bed was designed around a gas-solid\\u000a fluidized bed separator. Furthermore, the hydrodynamics of medium-solids consisting of wide-size-range magnetite powder (0.3–0.06\\u000a mm) and <1 mm fine coal were numerically studied. The simulation results show that the fluidization performance of the wide-size-range\\u000a medium-solid bed is good. The

Yue-min Zhao; Gong-min Li; Zhen-fu Luo; Chun-cheng Liang; Li-gang Tang; Zeng-qiang Chen; Hong-bo Xing

2011-01-01

112

Materials performance in the atmospheric fluidized-bed cogeneration air heater experiment  

SciTech Connect

The Atmospheric Fluidized-Bed Cogeneration Air Heater Experiment (ACAHE) sponsored by the US Department of Energy (DOE) was initiated to assess the performance of various heat-exchanger materials to be used in fluidized-bed combustion air heater systems. Westinghouse Electric Corporation, through subcontracts with Babcock & Wilcox, Foster Wheeler, and ABB Combustion Engineering Systems, prepared specifications and hardware for the ACAHE tests. Argonne National Laboratory contracted with Rockwell International to conduct tests in the DOE atmospheric fluidized-bed combustion facility. This report presents an overview of the project, a description of the facility and the test hardware, the test operating conditions, a summary of the operation, and the results of analyzing specimens from several uncooled and cooled probes exposed in the facility. Extensive microstructural analyses of the base alloys, claddings, coatings, and weldments were performed on specimens exposed in several probes for different lengths of time. Alloy penetration data were determined for several of the materials as a function of specimen orientation and the exposure location in the combustor. Finally, the data were compared with earlier laboratory test data, and the long-term performance of candidate materials for air-heater applications was assessed.

Natesan, K.; Podolski, W.; Wang, D.Y.; Teats, F.G. [Argonne National Lab., IL (United States); Gerritsen, W.; Stewart, A.; Robinson, K. [Rockwell International Corp., Canoga Park, CA (United States)

1991-02-01

113

An Experimental Investigation into the Fragmentation of Coal Particles in a Fluidized-Bed Combustor  

NASA Astrophysics Data System (ADS)

The fragmentation of coal plays a significant role in combustion in fluidized-bed boilers because it accelerates combustion and influences the distribution of particle sizes in the bed. Fine char particles produced by comminution can be carried out and increase the heat loss due to incomplete carbon conversion. The thermal fragmentation depends on the initial structure of the coal and how this structure changes with an increase in temperature when the particle is dropped into the combustion chamber. Experinments with nine Polish coals were carried out to quantify the fragmentation of burning coal particles. A bench-scale bubbling fluidized bed combustor was used to determine the degree of fragmentation for spherical coal particles during devolatilization and combustion. The effects of bed temperature, particle size and coal properties on the extent of primary and secondary fragmentation have been determined. It has been found that the combination of low porosity and high volatile content is the main factor responsible for the observed extent of fragmentation.

Kosowska-Galacbowska, Monika; Luckos, Adam

114

Tennessee Valley Authority atmospheric fluidized-bed combustor simulation interim annual report, January 1-December 31, 1979  

SciTech Connect

This report contains a detailed description of the work performed during 1979 for the Tennessee Valley Authority in support of the TVA Fluidized-Bed Combustor (FBC) Demonstration Plant Program. The work was carried out under task 4, modeling and simulation of atmospheric fluidized-bed combustor (AFBC) systems. The overall objective of this task is to develop a steady-state mathematical model with the capability of predicting trends in bed performance under various feed and operating conditions. As part of this effort, three predictive subprograms (subcodes) were developed during 1979: (1) bubble-growth subcode, (2) sorbent-coal ash elutriation and attrition subcode, and (3) coal combustion subcode. These codes, which are currently being tested with experimental data, are capable of predicting how some of the important operating variables in the AFBC affect its performance. After testing against field data, these subcodes will be incorporated into an overall AFBC system code, which was developed earlier at ORNL for analysis of the Department of Energy (DOE) Component Test and Integration Unit (CTIU) at Morgantown, West Virginia. In addition to these predictive subcodes, the overall system code previously developed for the CTIU is described. The material balance is closed, based on vendor-supplied data. This balance is then used to predict the heat transfer characteristics of the surfaces (submerged and freeboard) in the AFBC. Existing correlations for heat transfer in AFBC are used in the code along with thermophysical properties of the various streams.

Wells, J.W.; Krishnan, R.P.

1980-10-01

115

Development of Coal Fired Fluidized Bed Boilers. Volume I.  

National Technical Information Service (NTIS)

The report presents results of research and large-scale testing performed to develop a new type of boiler using fluidized combustion of coal. Objective of the program is the reduction in cost of coal-fired steam generation, while meeting air pollution con...

A. H. Bagnulo J. W. Bishop S. Ehrlich E. B. Robinson

1971-01-01

116

Simulation of coal gasification in a fluidized bed.  

National Technical Information Service (NTIS)

In this analysis of coal gasification, a fundamental approach is used where a set of multiphase (Eulerian) fluid dynamic equations, obtained either by a suitable averaging technique (Anderson and Jackson, 1976; Drew, 1971) or the formulations of continuum...

T. J. O'Brien

1996-01-01

117

PSNH's Northern Wood power project repowers coal-fired plant with new fluidized-bed combustor  

SciTech Connect

The Northern Wood Power project permanently replaced a 50-MW coal-burning boiler (Unit 5) at Public Service of New Hampshire's Schiller station with a state-of-the-art circulating fluidized bed wood-burning boiler of the same capacity. The project, completed in December 2006, reduced emissions and expanded the local market for low-grade wood. For planning and executing the multiyear, $75 million project at no cost to its ratepayers, PSNH wins Power's 2007 Marmaduke Award for excellence in O & M. The award is named for Marmaduke Surfaceblow, the fictional marine engineer/plant troubleshoot par excellence. 7 figs., 1 tab.

Peltier, R.

2007-08-15

118

Simulation of coal gasification in a fluidized bed  

SciTech Connect

In this analysis of coal gasification, a fundamental approach is used where a set of multiphase (Eulerian) fluid dynamic equations, obtained either by a suitable averaging technique (Anderson and Jackson, 1976; Drew, 1971) or the formulations of continuum mechanics (Drew, 1983), is used to describe the conservation of mass, momentum, and energy for three interpenetrating phases. The particles, like the fluidizing gas, are described as interpenetrating continua. Different particle types are treated as distinct phases; in this study, the feed coal and the bed char are represented as separate phases in order to account for their different histories. Constitutive laws account for the exchange of momentum between phases (``drag``) and interphase energy transfer. The stresses within the granular phases are determined by a formulation based on the kinetic theory, characterized by a ``granular temperature``. A computer code, based on this multiphase hydrodynamic model, has been developed at the Morgantown Energy Technology Center for the detailed simulation of gas and particle dynamics in heavily loaded coal conversion processes (Syamlal, Rogers, O`Brien, 1994; Syamlal, 1995). The hydrodynamic simulation showed the reactor operated in a jetting/bubbling mode. A gas jet penetrated a considerable distance into the bed, and then detached as ``bubbles`` which rose to the top of the column. The reaction scheme indicated that the feed coal did not begin to devolatilize until it had traversed this region, because of the time required to heat up. Thus, volatiles were not released in the jetting region of the bed, but higher in the bed. The oxygen fed with the coal, however, reacted immediately with the recirculating hot char. The net effect of the char reaction scheme was to created. CO, which burned in the region where.the jet detached, creating a, fairly stable ``flame``. The tar reaction scheme indicated that none of the tar escaped the bed.

O`Brien, T.J.

1996-12-31

119

Mild gasification of steam-conditioned bituminous coal in fluidized beds: Technical note  

SciTech Connect

A detailed systems analysis of a commercial-scale mild gasification process has been performed. The process includes (1) a conceptual design of the process, (2) mass and energy balances that were calculated with the use of the Advanced System for Process Engineering (ASPEN) process simulator, and (3) a detailed economic assessment that includes several sensitivity studies. In this conceptual study, 1 million tons per year, dry basis, of Pittsburgh No. 8 coal are conditioned with steam at 700/degree/F for 5 minutes in a fluidized-bed and devolatilized at 1000/degree/F for 3 minutes in a second fluidized-bed. Volatiles are condensed and liquid condensate and gas are separated. Liquid production is 340,000 tons per year (approximately 1,870,000 barrels per year) based on an increased liquid yield due to steam conditioning of 37 weight percent of dry, ash-free coal (DAF). This assumed yield is based on bench-scale experimental results for steam-conditioned coal (Graff 1987). Gas produced in the process is internally consumed for char heating and steam generation. Net char production is 466,000 ton/yr. 27 refs., 3 figs., 3 tabs.

Gessner, A.W.; Hand, T.J.; Klara, J.M.

1988-02-01

120

(Fluidized bed combustion of high-ash Indian coals): Foreign trip report, January 5, 1988March 16, 1988  

Microsoft Academic Search

The foreign research assignment at BHEL, Trichy, was undertaken to participate in the ongoing USAID\\/BHEL joint program in fluidized bed combustion (FBC). As part of this program, an experimental FBC research test facility has been designed, erected and commissioned at BHEL, Trichy, to conduct experiments on the combustion of high-ash Indian coals and coal washery rejects. The data will be

R. P. Krishnan; C. S. Daw

1988-01-01

121

Numerical simulation of the bubbling fluidized bed coal gasification by the kinetic theory of granular flow (KTGF)  

Microsoft Academic Search

A new numerical model based on the two-fluid model (TFM) including the kinetic theory of granular flow (KTGF) and complicated reactions has been developed to simulate coal gasification in a bubbling fluidized bed gasifier (BFBG). The collision between particles is described by KTGF. The coal gasification rates are determined by combining Arrhenius rate and diffusion rate for heterogeneous reactions or

Liang Yu; Jing Lu; Xiangping Zhang; Suojiang Zhang

2007-01-01

122

Advanced Atmospheric Fluidized-Bed Combustion Design--Spouted Bed: Final Report.  

National Technical Information Service (NTIS)

The spouted fluidized bed (SFB) is a hybrid of the spouted bed and the conventional fluidized bed. Because of the bed dynamics and the increased particle attrition in the spout zone the SFBC is expected to provide benefits over conventional fluidized bed ...

1988-01-01

123

Preliminary Assessment of the Health and Environmental Impacts of Fluidized-Bed Combustion of Coal as Applied to Electrical Utility Systems.  

National Technical Information Service (NTIS)

The objective of this study was to assess the health and environmental impacts of fluidized-bed combustion of coal (FBC), specifically as applied to base-load generation of electrical energy by utilities. The public health impacts of Fluidized-Bed Combust...

1977-01-01

124

Analysis of atmospheric fluidized bed combustion agglomerates. Final report  

SciTech Connect

Chemical and textural studies of AFBC agglomerates have revealed detailed information regarding the mechanisms of agglomeration. The formation of agglomerates in a silica sand bed can be described by a four step process: initial ash coatings of quartz grains; thickening of ash coatings and the formation of nodules; cementation of nodules to each other by a sulfated aluminosilicate matrix; and partial or complete melting of eutectic compositions to produce a sticky glass phase between grains and along fractures. Once agglomeration has begun, large scale solidification and restricted flow within the bed will lead to hot spots, wholesale melting and further agglomeration which ultimately forces a shutdown. Standard operating temperatures during normal AFBC runs come quite close to, or may actually exceed, the minimum temperatures for eutectic melting of the silicate phases in the coal and standard bed materials. The partially melted material may be expected to lead to the formation of dense, sticky areas within the bed, and the formation of hot spots which further exacerbate the problem. Ultimately, large scale bed agglomeration will result. Attempts to eliminate agglomeration by removal of sodium via an ion exchange process have yielded encouraging results. A second approach, used to raise melting temperatures within the bed, has been to use bed materials that may react with low-temperature minerals to produce high-temperature refractory phases such as mullite or other alkali and alkali-earth alumino-silicates.

Perkins, D. III; Brekke, D.W.; Karner, F.R.

1984-04-01

125

Atmospheric Fluidized Bed Combustion testing of North Dakota lignite  

SciTech Connect

The sulfur retention by the inherent alkali, and added limestone sorbent, perform about the same and are reasonably predictable within a range of about +-10% retention by application of alkali to sulfur ratio. Temperature has a substantial effect on the retention of sulfur by the inherent alkali or limestone. The temperature effect is not yet fully understood but it appears to be different for different coals and operational conditions. The emission of SO/sub 2/ from the fluid bed burning the Beulah lignite sample used for these tests can be controlled to meet or better the current emission standards. The injection of limestone to an alkali-to-sulfur molar ratio of 1.5 to 1, should lower the SO/sub 2/ emissions below the current requirement of 0.6 lb SO/sub 2//10/sup 6/ Btu to 0.4 lb SO/sub 2//10/sup 6/ Btu, a safe 33% below the standard. Agglomeration of bed material, and consequent loss of fluidization quality can be a problem when burning high sodium lignite in a silica bed. There appears, however, to be several ways of controlling the problem including the injection of calcium compounds, and careful control of operating conditions. The heat transfer coefficients measured in the CPC and GFETC tests are comparable to data obtained by other researchers, and agree reasonably well with empirical conditions. The NO/sub x/ emissions measured in all of the tests on Beulah lignite are below the current New Source Performance Standard of 0.5 lb NO/sub 2//10/sup 6/ Btu input. Combustion efficiencies for the Beulah lignite are generally quite high when ash recycle is being used. Efficiencies in the range of 98% to 99%+ have been measured in all tests using this fuel.

Goblirsch, G; Vander Molen, R H; Wilson, K; Hajicek, D

1980-05-01

126

Co-firing a pressurized fluidized-bed combustion system with coal and refuse derived fuels and/or sludges. Task 16  

SciTech Connect

The co-firing of waste materials with coal in utility scale power plants has emerged as an effective approach to produce energy and manage municipal waste. Leading this approach, the atmospheric fluidized-bed combustor (AFBC) has demonstrated its commercial acceptance in the utility market as a reliable source of power burning a variety of waste and alternative fuels. The fluidized bed, with its stability of combustion, reduces the amount of thermochemical transients and provides for easier process control. The application of pressurized fluidized-bed combustor (PFBC) technology, although relatively new, can provide significant enhancements to the efficient production of electricity while maintaining the waste management benefits of AFBC. A study was undertaken to investigate the technical and economic feasibility of co-firing a PFBC with coal and municipal and industrial wastes. Focus was placed on the production of electricity and the efficient disposal of wastes for application in central power station and distributed locations. Wastes considered for co-firing include municipal solid waste (MSW), tire-derived fuel (TDF), sewage sludge, and industrial de-inking sludge. Issues concerning waste material preparation and feed, PFBC operation, plant emissions, and regulations are addressed. This paper describes the results of this investigation, presents conclusions on the key issues, and provides recommendations for further evaluation.

DeLallo, M.; Zaharchuk, R.

1994-01-01

127

Scale-Up of Circulating Fluidized Bed Coal Combustors: Progress Report, Fourth Quarter, June 1, 1989-August 31, 1989.  

National Technical Information Service (NTIS)

The project is aimed at quantifying the effects of scale-up upon the hydrodynamics of circulating fluidized bed coal combustors (CFB). To this end, we have constructed at Cornell a cold CFB facility that can operate with controlled fluidization gas mixtur...

M. Y. Louge

1989-01-01

128

Fluidized-Bed Regeneration of Sulfated Dolomite from a Coal-Fired FBC Process by Reductive Decomposition.  

National Technical Information Service (NTIS)

A process for regenerating spent SO sub 2 sorbents has been developed on a PDU scale. Tymochtee dolomite that had been sulfated during fluidized-bed combustion of coal is regenerated (reductive decomposition of CaSO sub 4 to CaO and SO sub 2 ) by the inco...

J. C. Montagna G. J. Vogel G. W. Smith A. A. Jonke

1977-01-01

129

High-temperature chlorination of coal ash in a fluidized bed - 2. Recovery of iron, silicon, and titanium  

Microsoft Academic Search

While chlorinating coal ash in a gas-fluidized bed reactor to recover aluminum, other metals such as iron, silicon, and titanium also react to form gaseous metal chlorides. The best yields are achieved when both carbon monoxide and fluid coke are used as reducing agents. Typically, after 2 h of chlorination, 100% iron, 5% silicon, and 25% titanium are recovered. The

Anil K. Mehrotra; Leo A. Behie; P. Raj Bishnoi; William Y. Svrcek

1982-01-01

130

Continuous high pressure lump coal feeder design study. [fluidized bed processors  

NASA Technical Reports Server (NTRS)

A continuous lump coal dry feeder was developed for a pressurized fluidized bed combustor. The approach was to adapt the commercially available Fuller-Kinyon pump to feed coal against a pressure differential of 100 psi or more. The pump was modified and tests performed at various pressure differentials, with differently pitched screws, various screw rotational speeds, and various seal lengths and configurations. Successful operation of the modified Fuller-Kinyon pump was generally limited to pressure differentials of 60 psi or less. Although the results are not conclusive, test data and observations were made that indicated that higher pressure differentials could be attained by further modifications of the test setup. In particular, it is recommended that further testing be performed after replacing the 40-horsepower pump motor presently in the test setup with a motor having a significantly high power rating (thereby allowing pump operation with longer seals and at higher pressure differentials than those tested so far).

Fields, S. F.

1977-01-01

131

Hot corrosion of B-1900 superalloy by simulated fluidized bed coal combustor deposits  

SciTech Connect

Calcium sulfate deposits in fluidized bed coal combustors are thought to contribute to heat transfer tube hot corrosion observed in test beds. Although Na/sub 2/SO/sub 4/ caused catastrophic hot corrosion of B-1900 superalloy at 900/sup 0/C in air, the corrosion due to CaSO/sub 4//Na/sub 2/SO/sub 4/ mixtures resembled that of simple oxidation, both in scale appearance and kinetics. High scale calcium content suggested a solid state reaction with CaSO/sub 4/ that did not compromise the protective scale. Although trace vanadium pentoxide added to a high percentage CaSO/sub 4/ mixture was shown to be innocuous, trace lead oxide caused catastrophic hot corrosion. However, the mechanism is unknown. This suggests that the latter coal impurity warrants attention as a possible severe corrosive threat, although CaSO/sub 4/ itself appears innocuous in an oxidizing environment.

Stewart, S.F.C.; Shatynski, S.R.

1982-10-01

132

Effect of embedded tube size on heat transfer coefficients in a fluidized bed combustor  

Microsoft Academic Search

The local characteristics of total and radiative heat transfers to horizontal tubes of 60, 50, 42 and 32 mm outer diameter, immersed in a fluidized bed coal combustor were experimentally investigated. Heat transfer measurements were conducted in a 300 mm square water cooled fluidized bed combustor at atmospheric pressure. The test tubes were instrumented with a radiometer, a flux meter

R. Vadivel; V. N. Vedamurthy

1980-01-01

133

Coal slurry solids/coal fluidized bed combustion by-product mixtures as plant growth media  

USGS Publications Warehouse

Fine-textured, pyritic waste produced by coal cleaning is stored in slurry settling ponds that eventually require reclamation. Conventionally, reclamation involves covering the dewatered coal slurry solids (CSS) with 1.3 m of soil to allow plant growth and prevent acid generation by pyrite oxidation. This study was conducted to determine the feasiblity of a less costly reclamation approach that would eliminate the soil cover and allow direct seeding of plants into amended CSS materials. Potential acidity of the CSS would be neutralized by additions of fluidized-bed combustion by-product (FBCB), an alkaline by-product of coal combustion. The experiment involved two sources of CSS and FBCB materials from Illinois. Birdsfoot trefoil (Lotus corniculatus L.), tall fescue (Festuca arundinacea Schreb.), and sweet clover (Melilotus officinalis (L.) Lam.) were seeded in the greenhouse into pots containing mixtures of the materials. CSS-1 had a high CaCO3:FeS2 ratio and needed no FBCB added to compensate for its potential acidity. CSS-2 was mixed with the FBCB materials to neutralize potential acidity (labeled Mix A and B). Initial pH was 5.6, 8.8, and 9.2 for the CSS-1, Mix A, and Mix B materials, respectively. At the end of the 70-day experiment, pH was 5.9 for all mixtures. Tall fescue and sweet clover grew well in all the treatments, but birdsfoot trefoil had poor emergence and survival. Elevated tissue levels of B, Cd, and Se were found in some plants. Salinity, low moisture holding capacity, and potentially phytotoxic B may limit the efficacy of this reclamation method.

Darmody, R. G.; Green, W. P.; Dreher, G. B.

1998-01-01

134

Design of a 165 MWe reheat coal-fired circulating fluidized bed boiler for Nova Scotia Power Corporation  

SciTech Connect

In October 1989, a contract was awarded to Pyropower Corporation for the design, supply and erection of the 165 MW{sub e} reheat coal fired circulating fluidized bed boiler for the Point Aconi site in Nova Scotia, Canada. This order represented the largest capacity circulating fluidized bed (CFB) boiler sold to date. This paper presents the boiler design parameters, design arrangement and specific, unique design features such as the reheat system and reheat temperature control. A particular concern with the boiler design was the relatively high chlorine content in the coal fuel. To resolve this concern, a test burn was conducted in Pyropower's Research and Development facility in December 1989. The test burn and it's results are also examined.

Schaller, B. (Pyropower Corp. (US)); Darguzas, J. (Sargent and Lundy, Chicago, IL (USA)); Fraser, S. (Nova Scotia Power Corp., Halifax, NS (Canada))

1990-01-01

135

Nitric Oxide Reduction over Sewage Sludge and Coal Chars at Conditions Relevant to Staged Fluidized Bed Combustion  

NASA Astrophysics Data System (ADS)

The de-NOx potential of coal and of dried and pelletized sewage sludge, a waste-derived fuel candidate for cofiring with coal, is assessed. The experimental procedure is based on operation of a bench scale fluidized bed reactor where NO-doped nitrogen is contacted with batches of the fuel. A second type of experiment has been purposely designed to assess the loss of reactivity of chars toward gasification by NOx as char is heat-treated for pre-set times at temperatures typical of fluidized bed combustion. A simple phenomenological model is developed to shed light on the basic features of the interaction between heterogeneous char-NOx reaction and thermal annealing of the char.

Salatino, P.; Solimene, R.; Chirone, R.

136

Gaseous emissions from co-combustion of sewage sludge and coal\\/wood in a fluidized bed  

Microsoft Academic Search

Co-combustion of sewage sludge together with coal or wood has been investigated in two circulating fluidized bed (CFB) plants, a laboratory scale plant and a pilot scale 12MWth CFB boiler, in both of which the gas residence times are comparable to those in commercial plant. The investigation focuses on emissions of harmful gases from co-combustion compared to mono-combustion in CFB

B. Leckner; L.-E. Åmand; K. Lücke; J. Werther

2004-01-01

137

Hydrogen-Rich Gas Production by Cogasification of Coal and Biomass in an Intermittent Fluidized Bed  

PubMed Central

This paper presents the experimental results of cogasification of coal and biomass in an intermittent fluidized bed reactor, aiming to investigate the influences of operation parameters such as gasification temperature (T), steam to biomass mass ratio (SBMR), and biomass to coal mass ratio (BCMR) on hydrogen-rich (H2-rich) gas production. The results show that H2-rich gas free of N2 dilution is produced and the H2 yield is in the range of 18.25~68.13?g/kg. The increases of T, SBMR, and BCMR are all favorable for promoting the H2 production. Higher temperature contributes to higher CO and H2 contents, as well as H2 yield. The BCMR has a weak influence on gas composition, but the yield and content of H2 increase with BCMR, reaching a peak at the BCMR of 4. The H2 content and yield in the product gas increase with SBMR, whilst the content of CO increases first and then decreases correspondingly. At a typical case, the relative linear sensitivity coefficients of H2 production efficiency to T, SBMR, and BCMR were calculated. The results reveal that the order of the influence of the operation parameters on H2 production efficiency is T > SBMR > BCMR.

Wang, Li-Qun; Chen, Zhao-Sheng

2013-01-01

138

Hydrogen-rich gas production by cogasification of coal and biomass in an intermittent fluidized bed.  

PubMed

This paper presents the experimental results of cogasification of coal and biomass in an intermittent fluidized bed reactor, aiming to investigate the influences of operation parameters such as gasification temperature (T), steam to biomass mass ratio (SBMR), and biomass to coal mass ratio (BCMR) on hydrogen-rich (H2-rich) gas production. The results show that H2-rich gas free of N2 dilution is produced and the H2 yield is in the range of 18.25~68.13?g/kg. The increases of T, SBMR, and BCMR are all favorable for promoting the H2 production. Higher temperature contributes to higher CO and H2 contents, as well as H2 yield. The BCMR has a weak influence on gas composition, but the yield and content of H2 increase with BCMR, reaching a peak at the BCMR of 4. The H2 content and yield in the product gas increase with SBMR, whilst the content of CO increases first and then decreases correspondingly. At a typical case, the relative linear sensitivity coefficients of H2 production efficiency to T, SBMR, and BCMR were calculated. The results reveal that the order of the influence of the operation parameters on H2 production efficiency is T > SBMR > BCMR. PMID:24174911

Wang, Li-Qun; Chen, Zhao-Sheng

2013-01-01

139

Cyclone and fluidized bed combustion concepts for coal fired open cycle MHD  

Microsoft Academic Search

Predicted performances of fluidized bed and cyclone combustion schemes were compared as part of a recent conceptual design study of a sub-scale (250 MWt), open-cycle MHD Engineering Test Facility (ETF). Both combustion concepts were two-stage gasification\\/combustion systems designed for high slag\\/ash rejection with predictions for slag\\/ash rejection being greater than 99% and 90% for the fluidized bed and cyclone concepts

S. Omori; J. Hnat; J. Bazan; B. Biswas

1978-01-01

140

Summary evaluation of atmospheric pressure fluidized bed combustion applied to electric utility large steam generators. Volume I. Final report  

Microsoft Academic Search

A fluidized bed combustor (FBC) using limestone to absorb SOâ appears to have sound potential for burning high sulfur eastern coals (which are in ample supply) while staying within anti-pollution regulations. A literature search was conducted by the Alliance Research Center of Babcock and Wilcox for EPRI. The purpose: to collect available FBC data, analyze the state-of-the-art, to make initial

T. E. Dowdy; W. C. Lapple; J. B. Kitto; T. P. Stanoch; R. H. Boll; W. L. Sage; S. S. Strom

1976-01-01

141

Emissions of NO x and N 2O during co-combustion of dried sewage sludge with coal in a circulating fluidized bed combustor  

Microsoft Academic Search

Emissions of NOx and N2O were measured during mono-combustion of dried sewage sludge and co-combustion with coal in a bench-scale circulating fluidized bed combustor (CFBC). The results were compared with previous results obtained using a bubbling fluidized bed combustor (BFBC). The increase in NOx with sludge ash accumulation in the combustor was less for the CFBC than the BFBC, partly

Tadaaki Shimizu; Masanori Toyono

2007-01-01

142

Engineering Support Services for the DOE/GRI Coal-Gasification Research Program. Technical and Economic Assessment of the Westinghouse Fluidized-Bed Coal Gasification Process.  

National Technical Information Service (NTIS)

Kellogg was requested by DOE/GRI to perform a technical and economic assessment of the Westinghouse fluidized bed coal gasification process as applied to production of SNG equivalent to 250 billion BTU/day from Pittsburgh No. 8 coal. Based on operating ex...

D. A. Hubbard L. E. Bostwick R. W. Laramore T. R. Ethridge

1981-01-01

143

Pulsed atmospheric fluidized bed combustion. Technical progress report, January--March 1994.  

National Technical Information Service (NTIS)

Industra has completed design of the structure which surrounds the fluidized bed. Details regarding their efforts are discussed below. Duke/Fluor Daniel has begun overall design review and will provide comments and recommendations early in the second quar...

1994-01-01

144

Advanced Atmospheric Fluidized-Bed Combustion Design: Internally Circulating AFBC. Final Report.  

National Technical Information Service (NTIS)

This report defines and characterizes an advanced, industrial, fluidized-bed combustion concept - the internally circulating AFBC - having superior performance and cost characteristics. The internally circulating AFBC incorporates four major innovative fe...

D. L. Keairns H. K. Altiner J. R. Hamm M. M. Ahmed K. D. Weeks

1983-01-01

145

Fluidized Bed Retrofit Study on Consolidated Edison Arthur Kill No. 3 Generating Station. Step II. Conceptual Boiler Design.  

National Technical Information Service (NTIS)

The objective of this project was to study the feasibility of retrofitting an existing utility boiler to fire coal utilizing atmospheric fluidized bed combustion and to estimate the cost of a fluidized bed retrofit. The unit selected for the retrofit stud...

R. B. Covell S. L. Darling M. C. Tanca

1978-01-01

146

Hydrodynamics of a fluidized bed co-combustor for tobacco waste and coal.  

PubMed

The fluidization characteristics of binary mixtures containing tobacco stem (TS) and cation exchange resin (a substitute for coal) were studied in a rectangular bed with the cross-section area of 0.3 × 0.025 m(2). The presence of herbaceous biomass particles and their unique properties such as low density and high aspect ratio resulted in different fluidization behaviors. Three fluidization velocities, i.e. initial, minimum and full fluidization velocities, were observed as the TS mass fraction increased from 7% to 20%, and four hydrodynamic stages were experienced, including the static, segregation, transition and mixing stages, with increasing operational gas velocities. The results suggest that the operational gas velocity should be in the range of 2.0-5.0 times of the minimum fluidization velocity of the binary mixtures, and less than 7% TS mass fraction should be used in an existing bubbling fluidized bed. Higher TS fraction inclusion requires the introduction of central jet gas to improve the mixing effect. PMID:22750501

Zhang, Kai; Yu, Bangting; Chang, Jian; Wu, Guiying; Wang, Tengda; Wen, Dongsheng

2012-09-01

147

The O?-enriched air gasification of coal, plastics and wood in a fluidized bed reactor.  

PubMed

The effect of oxygen-enriched air during fluidized bed co-gasification of a mixture of coal, plastics and wood has been investigated. The main components of the obtained syngas were measured by means of on-line analyzers and a gas chromatograph while those of the condensate phase were off-line analysed by means of a gas chromatography-mass spectrometer (GC-MS). The characterization of condensate phase as well as that of the water used as scrubbing medium completed the performed diagnostics. The experimental results were further elaborated in order to provide material and substances flow analyses inside the plant boundaries. These analyses allowed to obtain the main substance distribution between solid, gaseous and condensate phases and to estimate the conversion efficiency of carbon and hydrogen but also to easily visualise the waste streams produced by the process. The process performance was then evaluated on the basis of parameters related to the conversion efficiency of fuels into valuable products (i.e. by considering tar and particulate as process losses) as well as those related to the energy recovery. PMID:21993077

Mastellone, Maria Laura; Zaccariello, Lucio; Santoro, Donato; Arena, Umberto

2012-04-01

148

Lewis Research Center's coal-fired, pressurized, fluidized-bed reactor test facility  

NASA Technical Reports Server (NTRS)

A 200-kilowatt-thermal, pressurized, fluidized-bed (PFB) reactor, research test facility was designed, constructed, and operated as part of a NASA-funded project to assess and evaluate the effect of PFB hot-gas effluent on aircraft turbine engine materials that might have applications in stationary-power-plant turbogenerators. Some of the techniques and components developed for this PFB system are described. One of the more important items was the development of a two-in-one, gas-solids separator that removed 95+ percent of the solids in 1600 F to 1900 F gases. Another was a coal and sorbent feed and mixing system for injecting the fuel into the pressurized combustor. Also important were the controls and data-acquisition systems that enabled one person to operate the entire facility. The solid, liquid, and gas sub-systems all had problems that were solved over the 2-year operating time of the facility, which culminated in a 400-hour, hot-gas, turbine test.

Kobak, J. A.; Rollbuhler, R. J.

1981-01-01

149

Release of sulfur and chlorine during cofiring RDF and coal in an internally circulating fluidized bed  

SciTech Connect

An internally circulating fluidized bed (ICFB) was applied to investigate the behavior of chlorine and sulfur during cofiring RDF and coal. The pollutant emissions in the flue gas were measured by Fourier transform infrared (FTIR) spectrometry (Gasmet DX-3000). In the tests, the concentrations of the species CO, CO{sub 2}, HCl, and SO{sub 2} were measured online. Results indicated when cofiring RDF and char, due to the higher content of chlorine in RDF, the formation of HCl significantly increases. The concentration of SO{sub 2} is relatively low because alkaline metal in the fuel ash can absorb SO{sub 2}. The concentration of CO emission during firing pure RDF is relatively higher and fluctuates sharply. With the CaO addition, the sulfur absorption by calcium quickly increases, and the desulfurization ratio is bigger than the dechlorination ratio. The chemical equilibrium method is applied to predict the behavior of chlorine. Results show that gaseous HCl emission increases with increasing RDF fraction, and gaseous KCl and NaCl formation might occur. 35 refs., 18 figs., 2 tabs.

Xiaolin Wei; Yang Wang; Dianfu Liu; Hongzhi Sheng; Wendong Tian; Yunhan Xiao [Chinese Academy of Sciences, Beijing (China). Institute of Mechanics, and Institute of Engineering Thermophysics

2009-03-15

150

Emission Characteristics of Co-combustion of Sewage Sludge with Olive Cake and Lignite Coal in a Circulating Fluidized Bed  

Microsoft Academic Search

In this study, a circulating fluidized bed (CFB) of 125 mm diameter and 1800 mm height was used to find the combustion characteristics of sewage sludge (SS) produced in Turkey. Sludge + olive cake, and sludge + lignite coal mixtures were burned separately. Various sludge-to-lignite coal and sludge-to-olive cake ratios (5\\/95, 10\\/90, 15\\/85, 20\\/80) were tried. On-line concentrations of major components (O2, SO2, CO2, CO, NOx,

Oner Yusuf Toraman; Hüseyin Topal; Oktay Bayat; Aysel T. Atimtay

2004-01-01

151

Study of instrumentation needs for process control and safety in coal fluidized-bed combustion systems  

SciTech Connect

A study was conducted to evaluate the current state of the art of instrumentation for planned and operating fluidized-bed combustion systems. This study is intended to identify instrumentation needs and serve as a data base for projects to develop this instrumentation. A considerable number of needs for measurements for which presently available instrumentation is not suitable were reported by respondents. The identified deficiencies are presented with the associated physical parameter ranges for FBC processes. New techniques and instrumentation under development, as well as some available alternative instruments, are discussed briefly. Also, newly instituted mechanisms for technical information exchange on instrumentation for fossil energy applications are identified. Development of instruments to meet the identified measurement deficiencies is recommended in order to ensure the feasibility of automatic control of large-scale fluidized-bed combustion systems, and to advance the state of the art of fluidized-bed combustion technology.

Herzenberg, C.L.; Griggs, K.E.; Henry, R.F.; Podolski, W.F.

1981-02-01

152

Advanced atmospheric fluidized-bed combustion design: internally circulating AFBC. Final report  

SciTech Connect

This report defines and characterizes an advanced, industrial, fluidized-bed combustion concept - the internally circulating AFBC - having superior performance and cost characteristics. The internally circulating AFBC incorporates four major innovative features (single fuel feed; jet-attrition-controlled sulfur removal; multiple air staging; and high-velocity, single vessel integral design using draft tube circulation) to achieve: high boiler thermal efficiency (approaching 90% through integral design, high combustion efficiency, and low sorbent consumption); fuel flexibility (single coal feed point, coal size up to nominal 2 in, flexible air distribution, capability of feeding and combusting gaseous and liquid fuels); high reliability (simplified fuel feed and solids handling); turndown flexibility (degree and ease of turndown achieved by integral segmented bed, staged air distribution); low sorbent requirements for high SO/sub 2/ control (Ca/S <2 for greater than 90% removal using jet-attrition-controlled sulfur removal); low NO/sub x/ emissions (0.1 lb/10/sup 6/ Btu through multiple stages of air injection and capability of maintaining high carbon content); compact design (single, shop-fabricated, rail-shippable units with capacity up to 150 x 10/sup 6/ Btu/hr for high-velocity operation); and low cost (simplified, integral function design with high efficiency). Westinghouse concludes that the internally circulating AFBC concept has great potential for industrial market acceptance because of its effective performance and high reliability at low steam generation costs. The concept merits further development to evolve its innovative features further and to determine its commercial design configuration and operating conditions.

Keairns, D.L.; Altiner, H.K.; Hamm, J.R.; Ahmed, M.M.; Weeks, K.D.; Bachovchin, D.M.; Kececioglu, I.; Ulerich, N.H.; Yang, W.C.

1983-01-01

153

The study of partitioning of heavy metals during fluidized bed combustion of sewage sludge and coal  

SciTech Connect

The behavior of Cd, Cr, Cu, Co, Mn, Ni, Pb, Zn, and Hg during the combustion tests of a dry granular sewage sludge on a fluidized bed combustor pilot (FBC) of about 0.3 MW was evaluated. The emissions of these heavy metals from mono-combustion were compared with those of co-combustion of the sludge with a bituminous coal. The effect of the addition of limestone was also studied in order to retain sulphur compounds and to verify its influence on the retention of heavy metals (HM). Heavy metals were collected and analyzed from different locations of the installation, which included the stack, the two cyclones, and the material removed from the bed. The results showed that the volatility of metals was rather low, resulting in emissions below the legal limits of the new directive on incineration, with the exception of Hg during the mono-combustion tests. The partitioning of metals, except for Hg, appeared to follow that of ashes, amounting to levels above 90% in the bed streams in the mono-combustion case. For co-combustion, there was a lower fixation of HM in the bed ashes, mostly originating essentially from the sewage sludge, ranging between 40% and 80%. It is believed that in this latter case, a slightly higher temperature could have enhanced the volatilization, especially of Cd and Pb. However these metals were then retained in fly ashes captured in the cyclones. In the case of Hg, the volatilisation was complete. The bed ashes were free of Hg and part of Hg was retained in the cyclones and the rest was emitted either with fine ash particles or in gaseous forms. In mono-combustion the Hg emissions from the stack (particles and gas) accounted, for about 50%. This appeared to have significantly decreased in the case of co-combustion, as only about 75% has been emitted, due to the retention effect of cyclone ashes.

Gulyurtlu, I.; Lopes, M.H.; Abelha, P.; Cabrita, I.; Oliveira, J.F.S. [INETI, Lisbon (Portugal)

2006-06-15

154

Char binder for fluidized beds  

DOEpatents

An arrangement that utilizes agglomerating coal as a binder to bond coal fines and recycled char into an agglomerate mass that will have suitable retention time when introduced into a fluidized bed 14 for combustion. The simultaneous use of coal for a primary fuel and as a binder effects significant savings in the elimination of non-essential materials and processing steps.

Borio, Richard W. (Somers, CT) [Somers, CT; Accortt, Joseph I. (Simsbury, CT) [Simsbury, CT

1981-01-01

155

Distribution of polycyclic aromatic hydrocarbons in fly ash during coal and residual char combustion in a pressurized fluidized bed  

SciTech Connect

To investigate the distribution of polycyclic aromatic hydrocarbons (PAHs) in fly ash, the combustion of coal and residual char was performed in a pressurized spouted fluidized bed. After Soxhlet extraction and Kuderna-Danish (K-D) concentration, the contents of 16 PAHs recommended by the United States Environmental Protection Agency (U.S. EPA) in coal, residual char, and fly ash were analyzed by a high-performance liquid chromatography (HPLC) coupled with fluorescence and diode array detection. The experimental results show that the combustion efficiency is lower and the carbon content in fly ash is higher during coal pressurized combustion, compared to the residual char pressurized combustion at the pressure of 0.3 MPa. Under the same pressure, the PAH amounts in fly ash produced from residual char combustion are lower than that in fly ash produced from coal combustion. The total PAHs in fly ash produced from coal and residual char combustion are dominated by three- and four-ring PAHs. The amounts of PAHs in fly ash produced from residual char combustion increase and then decrease with the increase of pressure in a fluidized bed. 21 refs., 1 fig., 4 tabs.

Hongcang Zhou; Baosheng Jin; Rui Xiao; Zhaoping Zhong; Yaji Huang [Nanjing University of Information Science and Technology, Nanjing (China)

2009-04-15

156

Formation of Double-Density Fluidized Bed and Application in Dry Coal Beneficiation  

Microsoft Academic Search

Currently utilized separators with air-dense medium fluidized bed can only produce two products with single-separating density. Two separators must be employed in series to generate three products, which leads to the complication of the technical system and on increase in construction investment and operation costs. Moreover, they are difficult to operate continuously owing to the problems of preparation and recovery

Lubin Wei; Qingru Chen; Yuemin Zhao

2003-01-01

157

FLUIDIZED-BED GASIFICATION OF PEAT, LIGNITE, SUBBITUMINOUS, AND PRETREATED BITUMINOUS COAL  

EPA Science Inventory

The report summarizes and compares results obtained from gasifying four different feedstocks in a pilot-scale fluidized-bed gasifier. Effects of operating variables (e.g., temperature, steam/carbon feed ratio, bed height, and feed rate) on carbon conversion and gas production are...

158

Modeling of coal gasification in an internally circulating fluidized bed reactor with draught tube  

Microsoft Academic Search

A predictive mathematical model is proposed based on the bed hydrodynamics, reaction kinetics and the empirical correlation of pyrolysis yields to predict gasification characteristics in an internally circulating fluidized bed gasifier with a draught tube. With the justifiable assumptions, steady state mathematical equations are derived and solved numerically. The simulated results of product gas composition, gas yield, carbon conversion, cold

Y. J Kim; J. M Lee; S. D Kim

2000-01-01

159

Production of heat insulator from coal ash discharged from a pressurized fluidized-bed combustor  

Microsoft Academic Search

In this work, the technology of using pressurized fluidized-bed combustor ash to produce a heat insulator by curing with steam at low temperature was studied and developed. It was found that (1) the produced heat insulator mainly consists of calcium silicate hydrates, calcium aluminate sulfate, and hemihydrate gypsum, (2) the produced heat insulator has three kinds of structures, which are

Yong Chen; Teruyuki Okajima; Shigekatsu Mori

1996-01-01

160

EMISSIONS FROM FBC (FLUIDIZED-BED COMBUSTION) BOILERS  

EPA Science Inventory

The paper provides perspective regarding the environmental acceptability of atmospheric-pressure fluidized-bed boilers, with particular emphasis on the application of this technology as a technique for utilizing coal in the industrial sector. It reviews emission sources within th...

161

SUPPORT STUDIES IN FLUIDIZED-BED COMBUSTION, 1978 ANNUAL REPORT  

EPA Science Inventory

The report gives results of laboratory- and process-scale EPA studies supporting the national development of atmospheric and pressurized fluidized-bed combustion (PFBC) of coal. Program objectives are: (1) to develop basic information needed to optimize the use of limestone for S...

162

Materials performance in fluidized-bed air heaters  

SciTech Connect

Development of cogeneration systems that involve combustion of coal in a fluidized bed and use of air heaters to generate hot air for turbine systems has been in progress for a number of years. The US Department of Energy (DOE) sponsored the Atmospheric Fluidized-Bed Cogeneration Air Heater Experiment (ACAHE) to assess the performance of various heat exchanger materials and establish confidence in the resultant designs of fluidized-bed-combustion air heater systems. Westinghouse Electric Corporation, in association with Babcock Wilcox, Foster Wheeler, and ABB/Combustion Engineering, prepared specifications and hardware for the ACAHE. Argonne National Laboratory, through a contract with the Rocketdyne Division of Rockwell International, conducted tests in the DOE 1.8 {times} 1.8 m atmospheric fluidized-bed combustion facility in El Segundo, California. This paper presents an assessment of the materials performance in fluidized bed environments and examines guidelines for materials selection on the basis of corrosion resistance in air and in combustion environments, mechanical properties, fabricability/thermal stability, and cost.

Natesan, K.; Podolski, W.

1991-12-01

163

Materials performance in fluidized-bed air heaters  

SciTech Connect

Development of cogeneration systems that involve combustion of coal in a fluidized bed and use of air heaters to generate hot air for turbine systems has been in progress for a number of years. The US Department of Energy (DOE) sponsored the Atmospheric Fluidized-Bed Cogeneration Air Heater Experiment (ACAHE) to assess the performance of various heat exchanger materials and establish confidence in the resultant designs of fluidized-bed-combustion air heater systems. Westinghouse Electric Corporation, in association with Babcock & Wilcox, Foster Wheeler, and ABB/Combustion Engineering, prepared specifications and hardware for the ACAHE. Argonne National Laboratory, through a contract with the Rocketdyne Division of Rockwell International, conducted tests in the DOE 1.8 {times} 1.8 m atmospheric fluidized-bed combustion facility in El Segundo, California. This paper presents an assessment of the materials performance in fluidized bed environments and examines guidelines for materials selection on the basis of corrosion resistance in air and in combustion environments, mechanical properties, fabricability/thermal stability, and cost.

Natesan, K.; Podolski, W.

1991-12-01

164

Combined-cycle power stations using clean-coal technologies: Thermodynamic analysis of full gasification versus fluidized bed combustion with partial gasification  

Microsoft Academic Search

A novel class of power plants for clean conversion of coal into power has been recently proposed, based on the concept of partial coal gasification and fluidized-bed combustion of unconverted char from gasification. This paper focuses on the thermodynamic aspects of these plants, in comparison with full gasification cycles, assessing their performance on the basis of a common advanced power

G. Lozza; P. Chiesa; L. DeVita

1996-01-01

165

Simulation of fluidized bed combustors. I - Combustion efficiency and temperature profile. [for coal-fired gas turbines  

NASA Technical Reports Server (NTRS)

A chemical engineering analysis is made of fluidized-bed combustor (FBC) performance, with FBC models developed to aid estimation of combustion efficiency and axial temperature profiles. The FBC is intended for combustion of pulverized coal and a pressurized FBC version is intended for firing gas turbines by burning coal. Transport phenomena are analyzed at length: circulation, mixing models, drifting, bubble wake lift, heat transfer, division of the FB reactor into idealized mixing cells. Some disadvantages of a coal FBC are pointed out: erosion of immersed heat-transfer tubing, complex feed systems, carryover of unburned coal particles, high particulate emission in off-streams. The low-temperature bed (800-950 C) contains limestone, and flue-gas-entrained SO2 and NOx can be kept within acceptable limits.

Horio, M.; Wen, C. Y.

1976-01-01

166

Performance and economics of co-firing a coal/waste slurry in advanced fluidized-bed combustion  

SciTech Connect

This study`s objective was to investigate co-firing a pressurized fluidized-bed combustor with coal and refuse-derived fuel for the production of electricity and the efficient disposal of waste. Performance evaluation of the pressurized fluidized-bed combustor (PFBC) power plant co-fired with refuse-derived fuel showed only slightly lower overall thermal efficiency than similar sized plants without waste co-firing. Capital costs and costs of electricity are within 4.2 percent and 3.2 percent, respectively, of waste-free operation. The results also indicate that there are no technology barriers to the co-firing of waste materials with coal in a PFBC power plant. The potential to produce cost-competitive electrical power and support environmentally acceptable waste disposal exists with this approach. However, as part of technology development, there remain several design and operational areas requiring data and verification before this concept can realize commercial acceptance. 3 refs., 3 figs., 4 tabs.

DeLallo, M.R.; Zaharchuk, R. [Parsons Power Group, Inc., Reading, PA (United States); Reuther, R.B.; Bonk, D.L. [USDOE Morgantown Energy Technology Center, WV (United States)

1996-09-01

167

Fluidized-bed sorbents  

SciTech Connect

The objectives of this project are to identify and demonstrate methods for enhancing long-term chemical reactivity and attrition resistance of zinc oxide-based mixed metal-oxide sorbents for desulfurization of hot coal-derived gases in a high-temperature, high-pressure (HTHP) fluidized-bed reactor. In this program, regenerable ZnO-based mixed metal-oxide sorbents are being developed and tested. These include zinc ferrite, zinc titanate, and Z-SORB sorbents. The Z-SORB sorbent is a proprietary sorbent developed by Phillips Petroleum Company (PPCo).

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

1994-10-01

168

Functionalization of polymers using an atmospheric plasma jet in a fluidized bed reactor and the impact on SLM-processes  

NASA Astrophysics Data System (ADS)

In order to improve thermoplastics (e.g. Polyamide, Polypropylene and Polyethylene) for Selective Laser Beam Melting (SLM) processes a new approach to functionalize temperature sensitive polymer powders in a large scale is investigated. This is achieved by combining an atmospheric pressure plasma jet and a fluidized bed reactor. Using pressurized air as the plasma gas, radicals like OH* are created. The functionalization leads to an increase of the hydrophilicity of the treated polymer powder without changing the bulk properties. Using the polymers in a SLM process to build single layers of melted material leads to an improvement of the melted layers.

Sachs, M.; Schmitt, A.; Schmidt, J.; Peukert, W.; Wirth, K.-E.

2014-05-01

169

Dual Fluidized Bed Biomass Gasification  

SciTech Connect

The dual fluidized bed reactor is a recirculating system in which one half of the unit operates as a steam pyrolysis device for biomass. The pyrolysis occurs by introducing biomass and steam to a hot fluidized bed of inert material such as coarse sand. Syngas is produced during the pyrolysis and exits the top of the reactor with the steam. A crossover arm, fed by gravity, moves sand and char from the pyrolyzer to the second fluidized bed. This sand bed uses blown air to combust the char. The exit stream from this side of the reactor is carbon dioxide, water and ash. There is a second gravity fed crossover arm to return sand to the pyrolysis side. The recirculating action of the sand and the char is the key to the operation of the dual fluidized bed reactor. The objective of the project was to design and construct a dual fluidized bed prototype reactor from literature information and in discussion with established experts in the field. That would be appropriate in scale and operation to measure the relative performance of the gasification of biomass and low ranked coals to produce a high quality synthesis gas with no dilution from nitrogen or combustion products.

None

2005-09-30

170

Engineer, Design, Construct, Test and Evaluate a Pressurized Fluidized Bed Pilot Plant Using High Sulfur Coal for Production of Electric Power: Environmental Assessment.  

National Technical Information Service (NTIS)

The objective of this program is to evaluate the commercial potential of a power generating concept that includes the pressurized, fluidized-bed (PFB) combustion of coal in conjunction with a combined gas-steam turbine cycle. The capability to burn high-s...

1979-01-01

171

Biomass yield and phosphorus availability to wheat grown on high phosphorus soils amended with phosphate inactivating residues. III. Fluidized bed coal combustion ash  

Microsoft Academic Search

The high phosphorus (P) soils in the poultry producing areas of Maryland's Eastern Shore pose an environmental risk to surface and ground water. Amendments with calcium (Ca) salts and calcium-rich byproducts have been considered in management practices for reducing P solubility in soil solution. A growth chamber experiment was conducted using fluidized bed coal ash (BA) at increasing rates on

Eton E. Codling; Charles L. Mulchi; Rufus L. Chaney

2002-01-01

172

Numerical analysis of the process of combustion and gasification of the polydisperse coke residue of high-ash coal under pressure in a fluidized bed  

SciTech Connect

A numerical analysis of the process of 'wet' gasification of high-ash coal under pressure in a low-temperature fluidized bed has been performed. The applicability of the previously developed computational model, algorithm, and program for the case under consideration has been noted. The presence of 'hot spots' (short-time local heatings) at different points of the bed has been confirmed.

A.Y. Maistrenko; V.P. Patskov; A.I. Topal; T.V. Patskova [National Academy of Sceinces of Ukraine, Kiev (Ukraine). Institute of Coal Power Technologies

2007-09-15

173

Research on coal-water fuel combustion in a circulating fluidized bed / Badanie spalania zawiesinowych paliw w?glowo-wodnych w cyrkulacyjnej warstwie fluidalnej  

NASA Astrophysics Data System (ADS)

In the paper the problem of heavily-watered fuel combustion has been undertaken as the requirements of qualitative coals combusted in power stations have been growing. Coal mines that want to fulfill expectations of power engineers have been forced to extend and modernize the coal enrichment plants. This causes growing quantity of waste materials that arise during the process of wet coal enrichment containing smaller and smaller under-grains. In this situation the idea of combustion of transported waste materials, for example in a hydraulic way to the nearby power stations appears attractive because of a possible elimination of the necessary deep dehydration and drying as well as because of elimination of the finest coal fraction loss arising during discharging of silted water from coal wet cleaning plants. The paper presents experimental research results, analyzing the process of combustion of coal-water suspension depending on the process conditions. Combustion of coal-water suspensions in fluidized beds meets very well the difficult conditions, which should be obtained to use the examined fuel efficiently and ecologically. The suitable construction of the research stand enables recognition of the mechanism of coal-water suspension contact with the inert material, that affects the fluidized bed. The form of this contact determines conditions of heat and mass exchange, which influence the course of a combustion process. The specificity of coal-water fuel combustion in a fluidized bed changes mechanism and kinetics of the process.

Kijo-Kleczkowska, Agnieszka

2012-10-01

174

Nucla circulating atmospheric fluidized bed demonstration project. Quarterly technical progress report, October--December 1990  

SciTech Connect

During the fourth quarter of 1990, steady-state performance testing at the Nucla Circulating Fluidized Bed (CFB) resumed under sponsorship of the US Department of Energy. Co-sponsorship of the Demonstration Test Program by the Electric Power Research Institute (EPRI) was completed on June 15, 1990. From October through December, 1990, Colorado-Ute Electric Association (CUEA) completed a total of 23 steady-state performance tests, 4 dynamic tests, and set operating records during November and December as the result of improved unit operating reliability. Highlight events and achievements during this period of operation are presented.

Not Available

1991-01-31

175

A novel three phase fluidized bed process for simultaneous selective flocculation and microbial desulfurization of high sulfur coal. Final report  

SciTech Connect

The purpose of this work was to investigate the feasibility of recovery and reclamation of ultrafine coal particles generated during the processing of coal. 10--35% of the total annual tonnage of coal in atypical coal preparation plant is estimated to be lost in forms of ultrafine particles during the mining, shipping, handling, and preparation of the coal. The technical feasibility of the proposed system which consisted of an integrated circuit of selective flocculation followed by microbial desulfurization, has been tested. The results indicate that using selective flocculation/froth flotation circuit, coal recoveryis 85% with 75% pyritic sulfur and 60% ash rejections. The remaining pyritic sulfur in the coal slurry was treated using microbial desulfurization in a draft-tube fluidized bed bioreactor. Using this reactor scheme considerable enhancement of the bioleaching rate was obtained. The results indicate that 90% rejection of pyritic sulfur can be achieved in less than 24 hrs. Note that the previously reported data for the bioleaching rate are from 4 to 12 days for the same amount of pyritic rejection. The results obtained in this work closely reflects the anticipated outcomes which were projected in the original proposal. Consequently, the results of this work implies a significant improvement in bioleaching process and the possibility for the commercialization of the microbial desulfurization process. Our results also indicate further improvement of this process by optimization of reactor sequence and operating conditions.

Fan, Liang-Shih; Bavarian, F.; Attia, Y.A.; Elzeky, M. [Ohio State Univ., Columbus, OH (United States)

1990-10-16

176

A novel three phase fluidized bed process for simultaneous selective flocculation and microbial desulfurization of high sulfur coal  

SciTech Connect

The purpose of this work was to investigate the feasibility of recovery and reclamation of ultrafine coal particles generated during the processing of coal. 10--35% of the total annual tonnage of coal in atypical coal preparation plant is estimated to be lost in forms of ultrafine particles during the mining, shipping, handling, and preparation of the coal. The technical feasibility of the proposed system which consisted of an integrated circuit of selective flocculation followed by microbial desulfurization, has been tested. The results indicate that using selective flocculation/froth flotation circuit, coal recoveryis 85% with 75% pyritic sulfur and 60% ash rejections. The remaining pyritic sulfur in the coal slurry was treated using microbial desulfurization in a draft-tube fluidized bed bioreactor. Using this reactor scheme considerable enhancement of the bioleaching rate was obtained. The results indicate that 90% rejection of pyritic sulfur can be achieved in less than 24 hrs. Note that the previously reported data for the bioleaching rate are from 4 to 12 days for the same amount of pyritic rejection. The results obtained in this work closely reflects the anticipated outcomes which were projected in the original proposal. Consequently, the results of this work implies a significant improvement in bioleaching process and the possibility for the commercialization of the microbial desulfurization process. Our results also indicate further improvement of this process by optimization of reactor sequence and operating conditions.

Fan, Liang-Shih; Bavarian, F.; Attia, Y.A.; Elzeky, M. (Ohio State Univ., Columbus, OH (United States))

1990-10-16

177

Coal slurry solids\\/coal fluidized bed combustion by-product mixtures as plant growth media  

Microsoft Academic Search

Fine-textured, pyritic waste produced by coal cleaning is stored in slurry settling ponds that eventually require reclamation. Conventionally, reclamation involves covering the dewatered coal slurry solids (CSS) with 1.3 m of soil to allow plant growth and prevent acid generation by pyrite oxidation. This study was conducted to determine the feasibility of a less costly reclamation approach that would eliminate

Robert G. Darmody; William P. Green; Gary B. Dreher

1998-01-01

178

Emissions of NO x and N 2O during co-combustion of dried sewage sludge with coal in a bubbling fluidized bed combustor  

Microsoft Academic Search

Emissions of NOx and N2O were measured during mono-combustion of dried sewage sludge and co-combustion with coal in a bench-scale bubbling fluidized bed combustor. After starting the sludge feed, emissions of NOx increased with time, but N2O emissions changed only slightly. After a certain amount of sludge was burned, the fuel was switched from sludge to coal. Emissions of NOx

Tadaaki Shimizu; Masanori Toyono; Hajime Ohsawa

2007-01-01

179

Investigation of flow behaviour of coal particles in a pilot-scale fluidized bed gasifier (FBG) using radiotracer technique.  

PubMed

Knowledge of residence time distribution (RTD), mean residence time (MRT) and degree of axial mixing of solid phase is required for efficient operation of coal gasification process. Radiotracer technique was used to measure the RTD of coal particles in a pilot-scale fluidized bed gasifier (FBG). Two different radiotracers i.e. lanthanum-140 and gold-198 labeled coal particles (100 gm) were independently used as radiotracers. The radiotracer was instantaneously injected into the coal feed line and monitored at the ash extraction line at the bottom and gas outlet at the top of the gasifier using collimated scintillation detectors. The measured RTD data were treated and MRTs of coal/ash particles were determined. The treated data were simulated using tanks-in-series model. The simulation of RTD data indicated good degree of mixing with small fraction of the feed material bypassing/short-circuiting from the bottom of the gasifier. The results of the investigation were found useful for optimizing the design and operation of the FBG, and scale-up of the gasification process. PMID:19457678

Pant, H J; Sharma, V K; Kamudu, M Vidya; Prakash, S G; Krishanamoorthy, S; Anandam, G; Rao, P Seshubabu; Ramani, N V S; Singh, Gursharan; Sonde, R R

2009-09-01

180

Coal Quality Impacts on Alkali Vapor Emissions from Pressurized Fluidized Bed Coal Combustors  

Microsoft Academic Search

This paper describes a modeling study that was undertaken to identify the major ways that coal quality affects alkali vapor emissions in PFBC exhaust systems. The central premise is that the impact of coal quality can be reliably evaluated from kinetically based predictions of the concentrations of NaCl, KC1, SO2. HCI, O2, and H2O in the exhaust from the bubbling

S. NIKSA; J. HELBLE; M. HARADAC; T. ANDO; J. SHIGETA; I. KAJIGAYA

2001-01-01

181

EXPERIMENTAL/ENGINEERING SUPPORT FOR ENVIRONMENTAL PROTECTION AGENCIES FLUIDIZED-BED COMBUSTION (FBC) PROGRAM: FINAL REPORT. VOLUME I. SULFUR OXIDE CONTROL  

EPA Science Inventory

The report gives results of an investigation of the desulfurization performance and attrition behavior of limestone and dolomite sorbents for atmospheric and pressurized fluidized-bed combustion (FBC) systems used with coal. It gives results of experimental thermogravimetric anal...

182

Fluidized bed combustor modeling  

NASA Technical Reports Server (NTRS)

A general mathematical model for the prediction of performance of a fluidized bed coal combustor (FBC) is developed. The basic elements of the model consist of: (1) hydrodynamics of gas and solids in the combustor; (2) description of gas and solids contacting pattern; (3) kinetics of combustion; and (4) absorption of SO2 by limestone in the bed. The model is capable of calculating the combustion efficiency, axial bed temperature profile, carbon hold-up in the bed, oxygen and SO2 concentrations in the bubble and emulsion phases, sulfur retention efficiency and particulate carry over by elutriation. The effects of bed geometry, excess air, location of heat transfer coils in the bed, calcium to sulfur ratio in the feeds, etc. are examined. The calculated results are compared with experimental data. Agreement between the calculated results and the observed data are satisfactory in most cases. Recommendations to enhance the accuracy of prediction of the model are suggested.

Horio, M.; Rengarajan, P.; Krishnan, R.; Wen, C. Y.

1977-01-01

183

Treatment of chromic tannery wastes using coal ashes from fluidized bed combustion of coal  

Microsoft Academic Search

A new method of treatment for chromic tannery wastes containing chrome and large amounts organic substances has been investigated. It has been found that the addition of certain types of coal ash from fluid bed combustion technologies, at a suitable temperature and pH, results in effective removal of Cr(III) compounds present in the wastes. The wastes could then be subjected

E. M. Bulewicz; A. Kozak; Z. Kowalski

1997-01-01

184

COAL CHAR GASIFICATION KINETICS IN A JET-FLUIDIZED BED (COMBUSTION, REACTION, RATE PHENOMENA)  

Microsoft Academic Search

The kinetics of gasification of -10 + 65 mesh coke and coal char with O(,2) and O(,2)-CO(,2) mixtures was studied in a continuous, bench scale, jet-fluidized reactor over a wide range of temperatures (900(DEGREES)C to > 1400(DEGREES)C) and bed depths under atmospheric pressure. The measured specific reaction rates of carbon ranged from 0.01 to 0.1 gram carbon reacting per gram

MING-YUAN KAO

1984-01-01

185

Treatment of chromic tannery wastes using coal ashes from fluidized bed combustion of coal  

SciTech Connect

A new method of treatment for chromic tannery wastes containing chrome and large amounts organic substances has been investigated. It has been found that the addition of certain types of coal ash from fluid bed combustion technologies, at a suitable temperature and pH, results in effective removal of Cr(III) compounds present in the wastes. The wastes could then be subjected to further processing in conventional biological treatment units. The method is very simple, cheap, and effective and could be used for chromic tannery wastes of different compositions.

Bulewicz, E.M.; Kozak, A.; Kowalski, Z. [Cracow Univ. of Technology (Poland). Inst. of Inorganic Chemistry and Technology] [Cracow Univ. of Technology (Poland). Inst. of Inorganic Chemistry and Technology

1997-10-01

186

Biomass fast pyrolysis in a fluidized bed reactor under N2, CO2, CO, CH4 and H2 atmospheres.  

PubMed

Biomass fast pyrolysis is one of the most promising technologies for biomass utilization. In order to increase its economic potential, pyrolysis gas is usually recycled to serve as carrier gas. In this study, biomass fast pyrolysis was carried out in a fluidized bed reactor using various main pyrolysis gas components, namely N(2), CO(2), CO, CH(4) and H(2), as carrier gases. The atmosphere effects on product yields and oil fraction compositions were investigated. Results show that CO atmosphere gave the lowest liquid yield (49.6%) compared to highest 58.7% obtained with CH(4). CO and H(2) atmospheres converted more oxygen into CO(2) and H(2)O, respectively. GC/MS analysis of the liquid products shows that CO and CO(2) atmospheres produced less methoxy-containing compounds and more monofunctional phenols. The higher heating value of the obtained bio-oil under N(2) atmosphere is only 17.8 MJ/kg, while that under CO and H(2) atmospheres increased to 23.7 and 24.4 MJ/kg, respectively. PMID:21232946

Zhang, Huiyan; Xiao, Rui; Wang, Denghui; He, Guangying; Shao, Shanshan; Zhang, Jubing; Zhong, Zhaoping

2011-03-01

187

Corrosion in atmospheric fluidized bed combustors—The reactions of CaSO4 with Cr, Ni, Co, Fe, and several alloys  

NASA Astrophysics Data System (ADS)

When coal is burned in the presence of limestone in an atmospheric fluidized-bed combustor (AFBC), the sulfur emission can be kept below acceptable EPA levels. Calcining of the limestone produces CaO, which then forms solid CaSO4 by a reaction with the SO2 produced during coal combustion. The internal components ( e.g., heat exchanger tubes) of the bed, however, become coated with a compact layer of CaSO4, CaO, and ash during combustion. It has been suggested that the presence of the sulfate on these hot metal surfaces is the cause of observed instances of accelerated oxidation-sulfidation. This paper presents results which support the above suggestion. The reactions between Cr, Ni, Co, Fe, alloy 800, 2.25 Cr-1 Mo, 9 Cr-1 Mo steels, or 304 stainless steel with CaSO4 were studied using differential thermal and thermogravimetric analyses. The reaction products were analyzed using X-ray diffraction, optical microscopy, and in some instances, X-ray energy dispersive analyses. The chromium-calcium sulfate reaction is the only case studied in which a sulfide is not formed. In that case, CaCr2O4 is the reaction product. In all other cases, the reactions are oxidation-sulfidation processes.

Ficalora, P. J.

1983-11-01

188

Pilot-scale fluidized-bed combustor testing cofiring animal-tissue biomass with coal as a carcass disposal option  

SciTech Connect

This study was performed to demonstrate the technical viability of cofiring animal-tissue biomass (ATB) in a coal-fired fluidized-bed combustor (FBC) as an option for disposing of specified risk materials (SRMs) and carcasses. The purpose of this study was to assess the technical issues of feeding/combusting ATB and not to investigate prion deactivation/pathogen destruction. Overall, the project successfully demonstrated that carcasses and SRMs can be cofired with coal in a bubbling FBC. Feeding ATB into the FBC did, however, present several challenges. Specifically, handling/feeding issues resulting from the small scale of the equipment and the extremely heterogeneous nature of the ATB were encountered during the testing. Feeder modifications and an overbed firing system were necessary. Through statistical analysis, it was shown that the ATB feed location had a greater effect on CO emissions, which were used as an indication of combustion performance, than the fuel type due to the feeding difficulties. Baseline coal tests and tests cofiring ATB into the bed were statistically indistinguishable. Fuel feeding issues would not be expected at the full scale since full-scale units routinely handle low-quality fuels. In a full-scale unit, the disproportionate ratio of feed line size to unit diameter would be eliminated thereby eliminating feed slugging. Also, the ATB would either be injected into the bed, thereby ensuring uniform mixing and complete combustion, or be injected directly above the bed with overfire air ports used to ensure complete combustion. Therefore, it is anticipated that a demonstration at the full scale, which is the next activity in demonstrating this concept, should be successful. As the statistical analysis shows, emissions cofiring ATB with coal would be expected to be similar to that when firing coal only. 14 refs., 5 figs., 6 tabs.

Bruce G. Miller; Sharon Falcone Miller; Elizabeth M. Fedorowicz; David W. Harlan; Linda A. Detwiler; Michelle L. Rossman [Pennsylvania State University, University Park, PA (United States). Energy Institute

2006-10-15

189

Fluidized bed calciner apparatus  

DOEpatents

An apparatus for remotely calcining a slurry or solution feed stream of toxic or hazardous material, such as ammonium diurante slurry or uranyl nitrate solution, is disclosed. The calcining apparatus includes a vertical substantially cylindrical inner shell disposed in a vertical substantially cylindrical outer shell, in which inner shell is disposed a fluidized bed comprising the feed stream material to be calcined and spherical beads to aid in heat transfer. Extending through the outer and inner shells is a feed nozzle for delivering feed material or a cleaning chemical to the beads. Disposed in and extending across the lower portion of the inner shell and upstream of the fluidized bed is a support member for supporting the fluidized bed, the support member having uniform slots for directing uniform gas flow to the fluidized bed from a fluidizing gas orifice disposed upstream of the support member. Disposed in the lower portion of the inner shell are a plurality of internal electric resistance heaters for heating the fluidized bed. Disposed circumferentially about the outside length of the inner shell are a plurality of external heaters for heating the inner shell thereby heating the fluidized bed. Further, connected to the internal and external heaters is a means for maintaining the fluidized bed temperature to within plus or minus approximately 25.degree. C. of a predetermined bed temperature. Disposed about the external heaters is the outer shell for providing radiative heat reflection back to the inner shell.

Owen, Thomas J. (West Richland, WA); Klem, Jr., Michael J. (Richland, WA); Cash, Robert J. (Richland, WA)

1988-01-01

190

Nitrogen evolution during the co-combustion of hydrothermally treated municipal solid waste and coal in a bubbling fluidized bed.  

PubMed

Nitrogen evolution was studied during the co-combustion of hydrothermally treated municipal solid wastes (HT MSW) and coal in a bubbling fluidized bed (BFB). HT MSW blending ratios as 10%, 20% and 30% (wt.%) were selected and tested at 700, 800, 900 °C. Emissions of NO and N2O from blends were measured and compared with the results of mono-combustion trials. Moreover, concentrations of precursors like NH3 and HCN were also quantified. The results are summarized as follows: NO emissions were predominant in all the cases, which rose with increasing temperature. The blending of HT MSW contributed to the NO reduction. N2O emissions decreased with temperature rising and the blending of HT MSW also presented positive effects. At 30% HT MSW addition, both NO and N2O emissions showed the lowest values (391.85 ppm and 55.33 ppm, respectively at 900 °C). For the precursors, more HCN was detected than NH3 and both played important roles on the gas side nitrogen evolution. PMID:24120458

Lu, Liang; Jin, Yuqi; Liu, Hongmei; Ma, Xiaojun; Yoshikawa, Kunio

2014-01-01

191

Co-firing of oil sludge with coal-water slurry in an industrial internal circulating fluidized bed boiler.  

PubMed

Incineration has been proven to be an alternative for disposal of sludge with its unique characteristics to minimize the volume and recover energy. In this paper, a new fluidized bed (FB) incineration system for treating oil sludge is presented. Co-firing of oil sludge with coal-water slurry (CWS) was investigated in the new incineration system to study combustion characteristics, gaseous pollutant emissions and ash management. The study results show the co-firing of oil sludge with CWS in FB has good operating characteristic. CWS as an auxiliary fuel can flexibly control the dense bed temperatures by adjusting its feeding rate. All emissions met the local environmental requirements. The CO emission was less than 1 ppm or essentially zero; the emissions of SO(2) and NO(x) were 120-220 and 120-160 mg/Nm(3), respectively. The heavy metal analyses of the bottom ash and the fly ash by ICP/AES show that the combustion ashes could be recycled as soil for farming. PMID:19249155

Liu, Jianguo; Jiang, Xiumin; Zhou, Lingsheng; Wang, Hui; Han, Xiangxin

2009-08-15

192

Utilization of blended fluidized bed combustion (FBC) ash and pulverized coal combustion (PCC) fly ash in geopolymer  

SciTech Connect

In this paper, synthesis of geopolymer from fluidized bed combustion (FBC) ash and pulverized coal combustion (PCC) fly ash was studied in order to effectively utilize both ashes. FBC-fly ash and bottom ash were inter-ground to three different finenesses. The ashes were mixed with as-received PCC-fly ash in various proportions and used as source material for synthesis of geopolymer. Sodium silicate (Na{sub 2}SiO{sub 3}) and 10 M sodium hydroxide (NaOH) solutions at mass ratio of Na{sub 2}SiO{sub 3}/NaOH of 1.5 and curing temperature of 65 deg. C for 48 h were used for making geopolymer. X-ray diffraction (XRD), scanning electron microscopy (SEM), degree of reaction, and thermal gravimetric analysis (TGA) were performed on the geopolymer pastes. Compressive strength was also tested on geopolymer mortars. The results show that high strength geopolymer mortars of 35.0-44.0 MPa can be produced using mixture of ground FBC ash and as-received PCC-fly ash. Fine FBC ash is more reactive and results in higher degree of reaction and higher strength geopolymer as compared to the use of coarser FBC ash. Grinding increases reactivity of ash by means of increasing surface area and the amount of reactive phase of the ash. In addition, the packing effect due to fine particles also contributed to increase in strength of geopolymers.

Chindaprasirt, Prinya [Department of Civil Engineering, Faculty of Engineering, Khon Kaen University, Khon Kaen 40002 (Thailand); Rattanasak, Ubolluk, E-mail: ubolluk@buu.ac.t [Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Burapha University, Chonburi 20131 (Thailand)

2010-04-15

193

Effect of pressure fluctuation on coal combustion in large-particle fluidized beds  

SciTech Connect

Atmospheric fluidised-bed combustors (afbcs) operate in the large-particle (>1 mm) fluidisation regime. Characteristics of this regime result in localisation of the devolatilisation and combustion of the volatilised gases to the neighbourhood of the coal-particle and volatile gas plumes arising from the injector region. The volatile gas plume resulting from the large-particle fluidisation dynamics wanders due to pressure fluctuations induced by bubble passage. The work reported in this paper was carried out to determine the impact of these characteristics on the design of afbcs. This has been accomplished by a linearised analysis of the governing equations to describe the periodic wandering of the volatile's plume diffusion flame and the corresponding fluctuation of the combustion rate.

Bywater, R.J.; Chung, P.M.

1983-05-01

194

Chemical and toxicological characterization of organic constituents in fluidized-bed and pulverized coal combustion: a topical report  

SciTech Connect

Coal combustion fly ash from both conventional pulverized coal combustion (PCC) and fluidized-bed combustion (FBC) have been characterized as to their organic constituents and microbial mutagenic activity. The PCC fly ash was collected from a commercial utility generating plant using a low sulfur coal. The FBC fly ash was from a bench-scale developmental unit at the Grand Forks Energy Technology Center. Bulk samples of each fly ash were extracted using benzene/methanol and further separated using high performance liquid chromatography (HPLC). Subfractions from the HPLC separation were analyzed by gas chromatography using both element-specific nitrogen-phosphorus detectors and flame ionization detectors. Microbial mutagenicity assay results indicated that the crude organic extracts were mutagenic, and that both the specific activity and the overall activity of the PCC material was greater than that of the FBC material. Comparison of results from assays using S. typhimurium, TA1538NR indicated that nitrated polycyclic aromatic compounds (PAC) were responsible for much of the mutagenic activity of the PCC material. Similar results were obtained for assays of the FBC organic extract with standard and nitroreductase-deficient strains of S. typhimurium, TA100 and TA1538. Mutagenically active HPLC fractions were analyzed using high resolution gas chromatography (HRGC) and GC mass spectrometry (GC/MS), as well as probe inlet low and high resolutions MS. The discovery and identification of nitrated, oxygenated PAC are important because the presence of both nitro and/or keto functionalities on certain PAC has been shown to confer or enhance mutagenic activity.

Chess, E.K.; Later, D.W.; Wilson, B.W.; Harris, W.R.; Remsen, J.F.

1984-04-01

195

Economics and concepts of industrial coal fluidized bed combustion in Brazil  

Microsoft Academic Search

The energy situation in Brazil is reviewed. Since domestic coal is abundant in Brazil, the authors foresee that coal will be the main alternative to fuel oils. They suggest the implementation of large scale coal-fired thermoelectric plants, and the utilization of domestic coal in industry, based on modern Brazilian technology. 10 refs.

M. Saddy; J. Szego

1981-01-01

196

Performance analysis of co-firing waste materials in an advanced pressurized fluidized-bed combustor  

Microsoft Academic Search

The co-firing of waste materials with coal in utility scale power plants has emerged as an effective approach to produce energy and manage municipal wastes. Leading this approach is the atmospheric fluidized-bed combustor (AFBC). It has demonstrated its commercial acceptance in the utility market as a reliable source of power by burning a variety of waste and alternative fuels. The

D. L. Bonk; H. M. McDaniel; M. R. Jr. DeLallo; R. Zaharchuk

1995-01-01

197

Alternative fuel firing in an atmospheric fluidized-bed combustion boiler. Final report. [Also with other waste fuels  

SciTech Connect

In 1981, Northern States Power Company converted its 15 MW French Island Unit No. 2 from a stoker-fired boiler to an atomspheric fluidized bed combustor designed to burn wood waste. A joint project between Northern States Power and the Electric Power Research Institute was subsequently established to determine the impact on operations, performance, and emissions of cofiring a variety of low-grade waste fuels with wood waste in this unit. Alternate waste fuels fired were shredded rubber tires, shredded railroad ties, refuse derived fuel, Minnesota peat, and sewage sludge. Each fuel was cofired with wood waste under steady boiler conditions for 50 to 100 hours. Results from the initial alternate fuel tests showed incomplete combustion of the fluidized bed combustor. To correct this problem the overfire air system was modified to improve mixing in the furnace volume above the fluidized bed. After the overfire air system was modified, the fluidized bed combustor proved able to burn all waste fuels effectively, except rubber tires which were not re-tested. Fuel handling problems were encountered with refuse derived fuel, peat and sewage sludge, but did not prevent their successful firing. Fluidized bed contamination was experienced with steel wire from rubber tires and stones and steel pieces from railroad ties. Also, the particulate scrubber was overloaded when firing high ash fuels such as rubber tires and peat. 2 refs., 21 figs., 32 tabs.

Miraglio, A.; Tegen, P.

1985-06-01

198

The O{sub 2}-enriched air gasification of coal, plastics and wood in a fluidized bed reactor  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer The effect of the O{sub 2} in the gasification stream of a BFB gasifier has been studied. Black-Right-Pointing-Pointer Main advantage of the O{sub 2}-enriched air is the increasing of the bed temperature. Black-Right-Pointing-Pointer No remarkable effects on tar reduction. Decreasing of recognized PAHs. Black-Right-Pointing-Pointer Gasification reactions completed inside the dense bed and splashing zone. Black-Right-Pointing-Pointer Polycondensation reactions occur mainly in the freeboard region. - Abstract: The effect of oxygen-enriched air during fluidized bed co-gasification of a mixture of coal, plastics and wood has been investigated. The main components of the obtained syngas were measured by means of on-line analyzers and a gas chromatograph while those of the condensate phase were off-line analysed by means of a gas chromatography-mass spectrometer (GC-MS). The characterization of condensate phase as well as that of the water used as scrubbing medium completed the performed diagnostics. The experimental results were further elaborated in order to provide material and substances flow analyses inside the plant boundaries. These analyses allowed to obtain the main substance distribution between solid, gaseous and condensate phases and to estimate the conversion efficiency of carbon and hydrogen but also to easily visualise the waste streams produced by the process. The process performance was then evaluated on the basis of parameters related to the conversion efficiency of fuels into valuable products (i.e. by considering tar and particulate as process losses) as well as those related to the energy recovery.

Mastellone, Maria Laura, E-mail: mlaura.mastellone@unina2.it [Department of Environmental Sciences-Second University of Naples, Via Vivaldi, 43 81100 Caserta (Italy); Zaccariello, Lucio; Santoro, Donato; Arena, Umberto [Department of Environmental Sciences-Second University of Naples, Via Vivaldi, 43 81100 Caserta (Italy)

2012-04-15

199

Granular filtration in a fluidized bed  

SciTech Connect

Successful development of advanced coal-fired power conversion systems often require reliable and efficient cleanup devices which can remove particulate and gaseous pollutants from high-temperature high-pressure gas stream. A novel filtration concept for particulate cleanup has been developed at the Morgantown Energy Technology Center (METC) of the U.S. Department of Energy. The filtration system consists of a fine metal screen filter immersed in a fluidized bed of granular material. As the gas stream passes through the fluidized bed, a layer of the bed granular material is entrained and deposited at the screen surface. This material provides a natural granular filter to separate fine particles from the gas stream passing through the bed. Since the filtering media is the granular material supplied by the fluidized bed, the filter is not subjected to blinding like candle filters. Because only the in-flowing gas, not fine particle cohesive forces, maintains the granular layer at the screen surface, once the thickness and permeability of the granular layer is stabilized, it remains unchanged as long as the in-flowing gas flow rate remains constant. The weight of the particles and the turbulent nature of the fluidized bed limits the thickness of the granular layer on the filter leading to a self-cleaning attribute of the filter. Batch mode filtration performance of the filter was first reported at the Ninth Annual Coal-Fueled Heat Engines, Advanced Pressurized Fluidized-Bed Combustion, and Gas Stream Cleanup Systems Contractors Review Meeting.

Mei, J.S.; Yue, P.C.; Halow, J.S.

1995-12-31

200

Characterization of fly ashes from circulating fluidized bed combustion (CFBC) boilers cofiring coal and petroleum coke  

Microsoft Academic Search

The chemistry, mineralogy, morphology, and particle size distribution were investigated in fly ashes from the burning of Datong (ShanXi, China) bituminous coal and the cofiring of Mideast high-sulfur petroleum coke (PC) with 30:70 (cal %) and 50:50 (cal %) blends of Datong bituminous coal in two commercial CFBC boilers. With the exception of CaO, the amounts of major oxides in

Feihu Li; Jianping Zhai; Xiaoru Fu; Guanghong Sheng

2006-01-01

201

Modeling of Fluidized-Bed Combustion of Coal. Volume VI. FBC: Data Base Management System User's Guide. Final Report.  

National Technical Information Service (NTIS)

This text is an introductory tutorial guide to the user of the Fluidized Bed Combustion (FBC) Data Base at the Massachusetts Institute of Technology. The text is designed to be used as a self-contained course for the novice user of this data base. No prev...

D. Lee Louis J.F S. E. Tung

1982-01-01

202

Modeling of fluidized-bed combustion of coal. Volume VI. FBC: data base management system user's guide. Final report  

Microsoft Academic Search

This text is an introductory tutorial guide to the user of the Fluidized Bed Combustion (FBC) Data Base at the Massachusetts Institute of Technology. The text is designed to be used as a self-contained course for the novice user of this data base. No previous experience with a computerized data base is assumed. However, the user is expected to know

Louis J. F; S. E. Tung; D. Lee

1982-01-01

203

Some developments in the feeding of coal to fluidized bed combustors  

NASA Technical Reports Server (NTRS)

Research is being done in the development of fluid bed combustors for high sulphur coal, using limestone or dolomite in the bed for removal of the sulphur. Operating units to date have proven the inadequacies of available material handling techniques for introduction and control of the coal and adsorbent to the beds. Larger units now being contemplated will pose formidable problems in this area. Some of the techniques which were developed for the existing pilot units and novel ideas under consideration for future, large production units are illustrated and described.

Caldwell, L. G.

1977-01-01

204

Fluidized bed combustion of refuse-derived fuel in presence of protective coal ash  

Microsoft Academic Search

Combustion of refuse-derived fuel (RDF) alone or together with other biomass leads to superheater fouling and corrosion in efficient power plants (with high steam values) due to vaporization and condensation of alkali chlorides. In this study, means were found to raise the portion of RDF to 40% enb without risk to boilers. This was done by co-firing RDF with coal

Eduardo Ferrer; Martti Aho; Jaani Silvennoinen; Riku-Ville Nurminen

2005-01-01

205

NUCLA Circulating Atmospheric Fluidized Bed Demonstration Project. 1989 Annual report, [January 1989--December 1989  

SciTech Connect

The report summarizes unit operating experience and test program progress for 1989 on Colorado-Ute Electric Association`s Nucla CFB Demonstration Program. During this period, the objectives of the Nucla Station operating group were to correct problems with refractory durability, resolve primary air fan capacity limitations, complete the high ash and high sulfur coal tests, switch to Salt Creek coal as the operating fuel, and make the unit available for testing without capacity restrictions. Each of these objectives was addressed and accomplished, to varying degrees, except for the completion of the high sulfur coal acceptance tests. (VC)

Not Available

1992-02-01

206

Tennessee Valley Authority Atmospheric Fluidized-Bed Combustor Simulation Interim Annual Report, January 1-December 31, 1979.  

National Technical Information Service (NTIS)

This report contains a detailed description of the work performed during 1979 for the Tennessee Valley Authority in support of the TVA Fluidized-Bed Combustor (FBC) Demonstration Plant Program. The work was carried out under task 4, modeling and simulatio...

J. W. Wells R. P. Krishnan

1980-01-01

207

Staged fluidized bed  

DOEpatents

The invention relates to oil shale retorting and more particularly to staged fluidized bed oil shale retorting. Method and apparatus are disclosed for narrowing the distribution of residence times of any size particle and equalizing the residence times of large and small particles in fluidized beds. Particles are moved up one fluidized column and down a second fluidized column with the relative heights selected to equalize residence times of large and small particles. Additional pairs of columns are staged to narrow the distribution of residence times and provide complete processing of the material.

Mallon, R.G.

1983-05-13

208

FEASIBILITY ANALYSIS FOR INSTALLING A CIRCULATING FLUIDIZED BED BOILER FOR COFIRING MULTIPLE BIOFUELS AND OTHER WASTES WITH COAL AT PENN STATE UNIVERSITY  

SciTech Connect

The Pennsylvania State University, under contract to the U.S. Department of Energy (DOE), National Energy Technology Laboratory (NETL) is performing a feasibility analysis on installing a state-of-the-art circulating fluidized bed (CFB) boiler and ceramic filter emission control device at Penn State's University Park campus for cofiring multiple biofuels and other wastes with coal, and developing a test program to evaluate cofiring multiple biofuels and coal-based feedstocks. Penn State currently operates an aging stoker-fired steam plant at its University Park campus and has spent considerable resources over the last ten to fifteen years investigating boiler replacements and performing life extension studies. This effort, in combination with a variety of agricultural and other wastes generated at the agricultural-based university and the surrounding rural community, has led Penn State to assemble a team of fluidized bed and cofiring experts to assess the feasibility of installing a CFB boiler for cofiring biomass and other wastes along with coal-based fuels. The objective of the project is being accomplished using a team that includes personnel from Penn State's Energy Institute and the Office of Physical Plant, Foster Wheeler Energy Services, Inc., and Cofiring Alternatives.

Bruce G. Miller; Sharon Falcone Miller; Robert Cooper; Douglas Donovan; John Gaudlip; Matthew Lapinsky; William Serencsits; Neil Raskin; Dale Lamke; Joseph J. Battista

2001-03-31

209

Heat transfer in freeboard region of fluidized beds  

Microsoft Academic Search

This research involved the study of heat transfer and fluid mechanic characteristics around a horizontal tube in the freeboard region of fluidized beds. Heat transfer coefficients were experimetnally measured for different bed temperatures, particle sizes, gas flow rates, and tube elevations in the freeboard region of air fluidized beds at atmospheric pressure. Local heat transfer coefficients were found to vary

S. Biyikli; K. Tuzla; J. C. Chen

1983-01-01

210

Preliminary comparison of theory and experiment for a conical, pressurized-fluidized-bed coal combustor  

NASA Technical Reports Server (NTRS)

A published model was used for a comparison of theory with an actual combustor burning caking bituminous coal and using limestone to reduce sulfur dioxide emission. Theoretical bed pressure drop was in good agreement with experiment. The burnable carbon elutriated was not in agreement with experiment, at least partly because the exhaust port was apparently below the transport disengaging height. The observed nitrogen oxides emission rate was about half the theoretical value. There was order-or-magnitude agreement of sulfur dioxide emission rates.

Patch, R. W.

1979-01-01

211

Particle withdrawal from fluidized bed systems  

DOEpatents

Method and apparatus for removing ash formed within, and accumulated at the lower portion of, a fluidized bed coal gasification reactor vessel. A supplemental fluidizing gas, at a temperature substantially less than the average fluidized bed combustion operating temperature, is injected into the vessel and upwardly through the ash so as to form a discrete thermal interface region between the fluidized bed and the ash. The elevation of the interface region, which rises with ash accumulation, is monitored by a thermocouple and interrelated with a motor controlled outlet valve. When the interface rises above the temperature indicator, the valve opens to allow removal of some of the ash, and the valve is closed, or positioned at a minimum setting, when the interface drops to an elevation below that of the thermocouple.

Salvador, Louis A. (Greensburg, PA); Andermann, Ronald E. (Arlington Heights, IL); Rath, Lawrence K. (Mt. Pleasant, PA)

1982-01-01

212

State of the art of pressurized fluidized bed combustion systems  

SciTech Connect

This report was prepared at the request of the Tennessee Valley Authority (TVA) to clarify the development status of the pressurized fluidized bed combustor (PFBC) and to place in perspective the problems which are yet to be solved before commercialization of the concept is practical. This report, in essence, supersedes the interim report published in 1979, Assessment of the State of the Art of Pressurized Fluidized Bed Combustion Systems. A brief overview of the PFBC concept is included citing potential advantages and disadvantages relative to atmospheric fluidized bed combustion (AFBC) and conventional pulverized coal plants. A survey of existing and developing PFBC experimental facilities is presented in some detail which includes the major accomplishments at the respective facilities. Recent data on plant emissions, turbine/gas cleanup systems, and overall efficiency are provided. Findings of several design studies are also discussed. The results of recent gas turbine and cascade tests have been encouraging although the full assessment of the accomplishments have not been made. The delay in construction of the Grimethorpe plant causes further delay in proof-testing full-size, rotating turbomachinery. Several parameters are recommended for further assessment in design studies including: (1) effect of turbine life on cost of power; and (2) effect of reduced gas turbine inlet temperature and pressure on cost of power.

Graves, R.L.

1980-09-01

213

ENVIRONMENTAL ASPECTS OF FLUIDIZED-BED COMBUSTION  

EPA Science Inventory

The report reviews the environmental aspects of fluidized-bed combustion (FBC) with respect to environmental media and specific pollutants. Emissions data indicate that FBC technology is a viable alternative to conventional coal combustion. Adverse impacts on health or the enviro...

214

Apparatus for controlling fluidized beds  

DOEpatents

An apparatus and process are disclosed for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance. 2 figs.

Rehmat, A.G.; Patel, J.G.

1987-05-12

215

Apparatus for controlling fluidized beds  

DOEpatents

An apparatus and process for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance.

Rehmat, Amirali G. (Westmont, IL); Patel, Jitendra G. (Bolingbrook, IL)

1987-05-12

216

Exploratory and basic fluidized-bed combustion studies. Quarterly report, April-June 1980. [Limestone and dolomite; USA  

SciTech Connect

This work supports the development studies for both atmospheric and pressurized fluidized-bed coal combustion. Laboratory and process development studies are aimed at providing needed information on limestone utilization, removal of particles and alkali metal compounds from the flue gas, control of SO/sub 2/ and trace pollutant emissions, and other aspects of fluidized-bed coal combustion. This report presents information on: (1) the development of a sorbent utilization prediction methodology, (2) studies of factors which affect limestone breakup and elutriation, (3) basic studies of limestone sulfation under combustion conditions, and (4) studies of the kinetics of the hydration of spent limestone.

Johnson, I.; Myles, K.M.; Swift, W.M.

1980-12-01

217

Advanced development of a pressurized ash agglomerating fluidized-bed coal gasification system. Fourth quarter progress report, July 1-September 30, 1982  

SciTech Connect

The overall objective of the Westinghouse coal gasification program is to demonstrate the viability of the Westinghouse pressurized, fluidized bed, gasification system for the production of medium-Btu fuel gas for syngas, electrical power generation, chemical feedstocks, or industrial fuels and to obtain performance and scaleup data for the process and hardware. Technical progress summaries and reports are presented for the following tasks: (1) process development unit (PDU) test operations and results (gasifier test TP-033-1 and maintenance and modifications); (2) process analysis (environmental characterization results, coal gas combustion results, and fines elutriation and consumption results); (3) cold flow scaleup (modifications and maintenance, operations, and data analysis); (4) process and component engineering and design (hot fines recycle modifications, and hot recycled fines); (5) laboratory support studies (gas-solids flow modeling and coal/ash behavior). 23 figures, 23 tables.

None

1983-02-17

218

Regenerative Portland cement sorbents for fluidized-bed combustion of coal  

SciTech Connect

Portland cements are commercially available construction materials that contain high concentrations of calcium silicates. The silicates are highly reactive towards SO/sub 2/ at temperatures and pressures encountered in atmospheric and pressurized FBC's. Of the Portland cements tested, PC III appears to have the highest sulfation capacity when sulfated by SO/sub 2/ at FBC conditions. A thermodynamic analysis of the sulfation of calcium silicates indicates that they are capable of reducing the concentration of SO/sub 2/ in FBC combustion gases to within the current EPA emission limits. The optimum temperature for sulfation of 16/20 mesh PC III pellets is about 1000/sup 0/C in comparison to about 875/sup 0/ for natural limestones. The higher observed optimum temperature is an advantage because combustion and power cycle efficiencies tend to increase as bed temperature increases. The reactions for regenerating sulfated calcium silicates are similar to those for regenerating calcium sulfate. However, the equilibrium partial pressures of SO/sub 2/ in the reductive decomposition of sulfated silicates are much higher than for sulfate lime. This implies that higher SO/sub 2/ concentrations will be attainable in the regenerator off-gas which will result in more economical conversion of SO/sub 2/ to sulfur or sulfuric acid. The sulfation capacity and regeneration efficiency of PC III pellets do not deteriorate with repeated sulfation/regeneration cycling. This indicates that PC III pellets are suitable for use in regenerative systems. The sulfation capacity of PC III is independent of pressure up to at least 10 atm.

Albanese, A S; Sethi, D; Steinberg, M

1980-01-01

219

Granular filtration in a fluidized bed  

SciTech Connect

Successful development of advanced coal-fired power conversion system often requires reliable and efficient cleanup devices that can remove particulate and gaseous pollutants from high-temperature, high- pressure gas streams. A novel filtration concept for particulate cleanup has been developed at the U.S. Department of Energy`s Morgantown Energy Technology Center (METC). The filtration system consists of a fine metal screen filter immersed in a fluidized bed of granular material. As the gas stream passes through the fluidized bed, a layer of the bed granular material is entrained and deposited at the screen surface. This material provides a natural granular filter to separate fine particles from the gas stream passing through the bed. Since the filtering media is the granular material supplied by the fluidized bed, the filter is not subjected to blinding like candle filters. Because only the in-flowing gas, not fine particle cohesive forces, maintains the granular layer at the screen surface, once the thickness and permeability of the granular layer are stabilized, it remains unchanged as long as the in-flowing gas flow rate remains constant. The weight of the particles and the turbulent nature of the fluidized bed limits the thickness of the granular layer on the filter leading to a self-cleaning attribute of the filter. The granular filtration testing system consisted of a filter, a two-dimensional fluidized bed, a continuous powder feeder, a laser-based, in-line particle counting, sizing, and velocimeter (PCSV), and a continuous solid feeding/bed material withdrawal system. The two-dimensional, transparent fluidized bed allowed clear observation of the general fluidized state of the granular material and the conditions under which fines are captured by the granular layer.

Mei, J.S.; Yue, P.C.

1996-12-31

220

Scaling of pressurized fluidized beds  

SciTech Connect

The project has two primary objectives. The first is to verify a set of hydrodynamic scaling relationships for commercial pressurized fluidized bed combustors (PFBC). The second objective is to investigate solids mixing in pressurized bubbling fluidized beds. American Electric Power`s (AEP) Tidd combined-cycle demonstration plant will provide time-varying pressure drop data to serve as the basis for the scaling verification. The verification will involve demonstrating that a properly scaled cold model and the Tidd PFBC exhibit hydrodynamically similar behavior. An important issue in PFBC design is the spacing of fuel feed ports. The feed spacing is dictated by the fuel distribution and the mixing characteristics within the bed. After completing the scaling verification, the cold model will be used to study the characteristics of PFBCs. A thermal tracer technique will be utilized to study mixing both near the fuel feed region and in the far field. The results allow the coal feed and distributor to be designed for optimal heating.

Guralnik, S.; Glicksman, L.R.

1994-10-01

221

Engineer, Design, Construct, Test and Evaluate a Pressurized Fluidized Bed Pilot Plant Using High Sulfur Coal for Production of Electric Power. Phase I. Preliminary Engineering. Annual Report, March 1, 1976--February 28, 1977.  

National Technical Information Service (NTIS)

Work performed from March 1, 1976 to February 28, 1977 to Engineer and Design a Pressurized, Fluidized Bed Pilot Plant using high sulfur coal for production of electric power is summarized. A conceptual design of a 500 MW commercial power plant is describ...

1977-01-01

222

FEASIBILITY ANALYSIS FOR INSTALLING A CIRCULATING FLUIDIZED BED BOILER FOR COFIRING MULTIPLE BIOFUELS AND OTHER WASTES WITH COAL AT PENN STATE UNIVERSITY  

SciTech Connect

The Pennsylvania State University, under contract to the U.S. Department of Energy, National Energy Technology Laboratory is performing a feasibility analysis on installing a state-of-the-art circulating fluidized bed boiler and ceramic filter emission control device at Penn State's University Park campus for cofiring multiple biofuels and other wastes with coal, and developing a test program to evaluate cofiring multiple biofuels and coal-based feedstocks. The objective of the project is being accomplished using a team that includes personnel from Penn State's Energy Institute, Office of Physical Plant, and College of Agricultural Sciences; Foster Wheeler Energy Services, Inc.; Parsons Energy and Chemicals Group, Inc.; and Cofiring Alternatives. During this reporting period, the final technical design and cost estimate were submitted to Penn State by Foster Wheeler. In addition, Penn State initiated the internal site selection process to finalize the site for the boiler plant.

Bruce G. Miller; Sharon Falcone Miller; Robert Cooper; Douglas Donovan; John Gaudlip; Matthew Lapinsky; William Serencsits; Neil Raskin; Tom Steitz

2002-10-14

223

Sulfation phenomena in fluidized bed combustion systems  

Microsoft Academic Search

Fluidized bed combustors (FBCs) are noted for their ability to capture SO2 in situ via direct reaction with Ca-based sorbents. However, despite more than 30 years of intensive study of sulfation processes in atmospheric FBC boilers and numerous laboratory studies, there are still many uncertainties and disagreements on the subject. In particular, the mechanisms of the sulfation reaction are still

E. J. Anthony; D. L. Granatstein

2001-01-01

224

Staged fluidized bed  

DOEpatents

Method and apparatus for narrowing the distribution of residence times of any size particle and equalizing the residence times of large and small particles in fluidized beds. Particles are moved up one fluidized column and down a second fluidized column with the relative heights selected to equalize residence times of large and small particles. Additional pairs of columns are staged to narrow the distribution of residence times and provide complete processing of the material.

Mallon, Richard G. (Livermore, CA)

1984-01-01

225

Fluidized bed combustion  

SciTech Connect

The invention relates to fluidized bed combustors that might tilt in use so that the depth of the bed progressively changes across its width. Air is supplied from two or more sources and means are provided to vary the flow from the sources as the bed tilts so that the air supplied to the portion of the bed of increased depth is increased relatively to the air supplied to the portion of the bed of lesser depth.

Hodgkin, A.F.

1980-12-16

226

A review of the efficacy of silicon carbide hot-gas filters in coal gasification and pressurized fluidized bed combustion environments  

SciTech Connect

Reviews of relevant literature and interviews with individuals cognizant of the state of the art in ceramic filters for hot-gas cleaning were conducted. Thermodynamic calculations of the stability of various ceramic phases were also made. Based on these calculations, reviews, and interviews, conclusions were reached regarding the use of silicon carbide-based ceramics at hot-gas filter media. Arguments are presented that provide the basis for the conclusion that high-purity silicon carbide is a viable material in the integrated coal gasification combined cycle (IGCC) and pressurized fluidized-bed combustion (PFBC) environments which were examined. Clay-bonded materials are, the authors concluded, suspect for these applications, their extensive use notwithstanding. Operations data reviewed focused primarily on clay-bonded filters, for which a great deal of experience exists. The authors used the clay-bonded filter experience as a point of reference for their review and analysis.

Judkins, R.R.; Stinton, D.P.; DeVan, J.H. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

1996-07-01

227

Fluidized-bed-fired industrial boilers  

SciTech Connect

E. Keeler Company and Dorr-Oliver, Inc. have joined to design, market and manufacture atmospheric fluidized-bed-fired boilers. The first contract, called Shamokin, was a 23,400 lb/hr unit fired with anthracite culm having a heating value of 4000 Btu/lb and 67% ash. The Department of Energy sponsored this plant as a demonstration project. Boiler erection is nearly complete and start-up is scheduled for mid-1981. In conjunction with the Shamokin project, a line of fluidized-bed-fired boilers to 250,000 lb/hr has been developed for conventional solid fuels. The development of fluidized-bed-fired, industrial boilers is in its very early stages. At this point, it is not possible for any manufacturer to claim extensive operating experience with any particular design under the varied applications normal to industrial watertube boilers. Many different designs and approaches will develop over the next few years and until there has been some operating experience, it is not possible to evaluate just what share of the future industrial boiler market will utilize fluidized-bed firing.

Leon, A.M.; McCoy, D.E.

1981-01-01

228

Control of effluents from fluidized bed steam generators  

Microsoft Academic Search

This paper reviews in detail emissions data, the equipment and operation controlling effluents in the Georgetown University Atmospheric Fluidized Bed Boiler (100 M lb\\/h saturated steam capacity). Advantages of latter designs, including the Shell Netherlands Atmospheric Fluidized Bed Boiler (110 M lb\\/h steam capacity, superheated to 923F), that are anticipated, are mentioned. Data and information not available in the references

B. T. Sinn; J. A. Garcia-Malloi; D. A. Toth

1983-01-01

229

Advanced development of a pressurized ash agglomerating fluidized-bed coal gasification system: Topical report, Process analysis, FY 1983  

SciTech Connect

KRW Energy Systems, Inc., is engaged in the continuing development of a pressurized, fluidized-bed gasification process at its Waltz Mill Site in Madison, Pennsylvania. The overall objective of the program is to demonstrate the viability of the KRW process for the environmentally-acceptable production of low- and medium-Btu fuel gas from a variety of fossilized carbonaceous feedstocks and industrial fuels. This report presents process analysis of the 24 ton-per-day Process Development Unit (PDU) operations and is a continuation of the process analysis work performed in 1980 and 1981. Included is work performed on PDU process data; gasification; char-ash separation; ash agglomeration; fines carryover, recycle, and consumption; deposit formation; materials; and environmental, health, and safety issues. 63 figs., 43 tabs.

None

1987-07-31

230

Biparticle fluidized bed reactor  

DOEpatents

A fluidized bed reactor system which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves.

Scott, Charles D. (Oak Ridge, TN)

1993-01-01

231

Biparticle fluidized bed reactor  

DOEpatents

A fluidized bed reactor system is described which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary and tertiary particulate phases, continuously introduced and removed simultaneously in the cocurrent and countercurrent mode, act in a role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Means for introducing and removing the sorbent phases include feed screw mechanisms and multivane slurry valves. 3 figs.

Scott, C.D.; Marasco, J.A.

1996-02-27

232

Biparticle fluidized bed reactor  

DOEpatents

A fluidized bed reactor system which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary and tertiary particulate phases, continuously introduced and removed simultaneously in the cocurrent and countercurrent mode, act in a role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Means for introducing and removing the sorbent phases include feed screw mechanisms and multivane slurry valves.

Scott, Charles D. (Oak Ridge, TN); Marasco, Joseph A. (Kingston, TN)

1996-01-01

233

Biparticle fluidized bed reactor  

DOEpatents

A fluidized bed reactor system utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves.

Scott, Charles D. (Oak Ridge, TN); Marasco, Joseph A. (Kingston, TN)

1995-01-01

234

Biparticle fluidized bed reactor  

DOEpatents

A fluidized bed reactor system utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves. 3 figs.

Scott, C.D.; Marasco, J.A.

1995-04-25

235

Control of acid gases using a fluidized bed adsorber.  

PubMed

During incineration, secondary pollutants such as acid gases, organic compounds, heavy metals and particulates are generated. Among these pollutants, the acid gases, including sulfur oxides (SO(x)) and hydrogen chloride (HCl), can cause corrosion of the incinerator piping and can generate acid rain after being emitted to the atmosphere. To address this problem, the present study used a novel combination of air pollution control devices (APCDs), composed of a fluidized bed adsorber integrated with a fabric filter. The major objective of the work is to demonstrate the performance of a fluidized bed adsorber for removal of acid gases from flue gas of an incinerator. The adsorbents added in the fluidized bed adsorber were mainly granular activated carbon (AC; with or without chemical treatment) and with calcium oxide used as an additive. The advantages of a fluidized bed reactor for high mass transfer and high gas-solid contact can enhance the removal of acid gases when using a dry method. On the other hand, because the fluidized bed can filter particles, fine particles prior to and after passing through the fluidized bed adsorber were investigated. The competing adsorption on activated carbon between different characteristics of pollutants was also given preliminary discussion. The results indicate that the removal efficiencies of the investigated acid gases, SO(2) and HCl, are higher than 94 and 87%, respectively. Thus, a fluidized bed adsorber integrated with a fabric filter has the potential to replace conventional APCDs, even when there are other pollutants at the same time. PMID:12935758

Chiang, Bo-Chin; Wey, Ming-Yen; Yeh, Chia-Lin

2003-08-01

236

Modeling of fluidized-bed combustion of coal. Volume VI. FBC: data base management system user's guide. Final report  

SciTech Connect

This text is an introductory tutorial guide to the user of the Fluidized Bed Combustion (FBC) Data Base at the Massachusetts Institute of Technology. The text is designed to be used as a self-contained course for the novice user of this data base. No previous experience with a computerized data base is assumed. However, the user is expected to know how to operate his or her computer terminal. The FBC Data Base was developed using the Model 204 Data Base Management System (M204). It runs under the VS1 operating system on the IBM System/370 computer at MIT's Information Processing Service. Although VS1 is a batch system, one of the M204 subroutines allows the data base to be used interactively like any other on-line system. As long as this subroutine is being executed, the data base can be accessed on-line. The FBC Data Base is designed to serve two purposes: First, it is an electronic library where experimental data related to fluidized bed combustion are stored on an article by article basis. Secondly, it serves as a research tool with which the user may: retrieve specific data; perform calculations with part or all of the retrieved data; or display the results in a number of ways. These two purposes are fulfilled by means of customized application programs. There are two categories of application programs: one serces the library purpose and the other serves the research purpose. Some programs are designed to perform one function only while others may perform more than one functions.

Louis J.F.; Tung, S.E.; Lee, D.

1982-05-01

237

Predictive models for circulating fluidized bed combustors  

SciTech Connect

The overall objective of this investigation is to develop experimentally verified models for circulating fluidized bed (CFB) combustors. The purpose of these models is to help American industry, such as Combustion Engineering, design and scale-up CFB combustors that are capable of burning US Eastern high sulfur coals with low SO{sub x} and NO{sub x} emissions. In this report, presented as a technical paper, solids distributions and velocities were computed for a PYROFLOW circulating fluidized bed system. To illustrate the capability of the computer code an example of coal-pyrite separation is included, which was done earlier for a State of Illinois project. 24 refs., 20 figs., 2 tabs.

Gidaspow, D.

1989-11-01

238

Fast fluidized bed steam generator  

DOEpatents

A steam generator in which a high-velocity, combustion-supporting gas is passed through a bed of particulate material to provide a fluidized bed having a dense-phase portion and an entrained-phase portion for the combustion of fuel material. A first set of heat transfer elements connected to a steam drum is vertically disposed above the dense-phase fluidized bed to form a first flow circuit for heat transfer fluid which is heated primarily by the entrained-phase fluidized bed. A second set of heat transfer elements connected to the steam drum and forming the wall structure of the furnace provides a second flow circuit for the heat transfer fluid, the lower portion of which is heated by the dense-phase fluidized bed and the upper portion by the entrained-phase fluidized bed.

Bryers, Richard W. (Flemington, NJ); Taylor, Thomas E. (Bergenfield, NJ)

1980-01-01

239

Emissions During Co-Firing of RDF-5 with Coal in a 22 t/h Steam Bubbling Fluidized Bed Boiler  

NASA Astrophysics Data System (ADS)

The co-firing of biomass and fossil fuel in the same power plant is one of the most important issues when promoting the utilization of renewable energy in the world. Recently, the co-firing of coal together with biomass fuel, such as "densified refuse derived fuel" (d-RDF or RDF-5) or RPF (refuse paper & plastic fuel) from waste, has been considered as an environmentally sound and economical approach to both waste remediation and energy production in the world. Because of itscomplex characteristics when compared to fossil fuel, potential problems, such as combustion system stability, the corrosion of heat transfer tubes, the qualities of the ash, and the emissionof pollutants, are major concerns when co-firing the biomass fuel with fossil fuel in a traditional boiler. In this study, co-firing of coal with RDF-5 was conducted in a 22t/h bubbling fluidized bed (BFB) steam boiler to investigate the feasibility of utilizing RDF-5 as a sustainable fuels in a commercial coal-fired steam BFB boiler. The properties of the fly ash, bottom ash, and the emission of pollutants are analyzed and discussed in this study.

Wan, Hou-Peng; Chen, Jia-Yuan; Juch, Ching-I.; Chang, Ying-Hsi; Lee, Hom-Ti

240

Evaluation of PCDD/Fs and metals emission from a circulating fluidized bed incinerator co-combusting sewage sludge with coal.  

PubMed

The emission characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and heavy metals were evaluated during co-combustion of sewage sludge with coal from a circulating fluidized bed incinerator. The stack gas, slag and fly ash samples were sampled and analyzed. The gas-cleaning system consisted of electrostatic precipitators and a semi-dry scrubber. Results showed that the stack gas and fly ash exhibited mean dioxin levels of 9.4 pg I-TEQ/Nm3 and 11.65 pg I-TEQ/g, respectively, and showed great similarities in congener profiles. By contrast, the slag presented a mean dioxin level of 0.15 pg I-TEQ/g and a remarkable difference in congener profiles compared with those of the stack gas and fly ash. Co-combusting sewage sludge with coal was able to reduce PCDD/Fs emissions significantly in comparison with sewage sludge mono-combustion. The leaching levels of Hg, Pb, Cd, Ni, Cr, Cu, and As in the fly ash and slag were much lower than the limits of the environmental protection standard in China. These suggest that the co-combustion of sewage sludge and coal is an advisable treatment method from an environmental perspective. PMID:23586319

Zhang, Gang; Hai, Jing; Cheng, Jiang; Cai, Zhiqi; Ren, Mingzhong; Zhang, Sukun; Zhang, Jieru

2013-01-01

241

Feasibility study on solidification of municipal solid waste incinerator fly ash with circulating fluidized bed combustion coal fly ash.  

PubMed

The objective of this study was to assess the feasibility of solidification of municipal solid waste incinerator (MSWI) fly ash with circulation fluidized bed combustion (CFBC) fly ash, which is unsuitable as a cement replacement due to its high amounts of carbon, lime and anhydrite. The solidification process was conducted on samples prepared from MSWI fly ash, binders (cement clinkers and CFBC fly ash were mixed at two replacement ratios) and water (water/solid weight ratio = 0.4), among which the MSWI fly ash replaced each binder at the ratio of 0, 20, 40, 60 and 80% by dry weight. The samples were subjected to compressive strength tests and Toxicity Characteristic Leaching Procedure and the results showed that all solidified MSWI fly ash can meet the landfill standard imposed by US EPA after 28 days of curing. Micro-analysis (X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectrophotometry) revealed that the main hydrate products were C-S-H gel and ettringite, which have a positive effect on heavy metals retention. Therefore, this method provides a possibility to achieve a cheap and effective solution for MSWI fly ash management and use for CFBC fly ash. PMID:19423575

Liu, Wenshi; Hou, Haobo; Zhang, Chuhao; Zhang, Dajie

2009-05-01

242

Fluidized-bed-fired industrial boilers  

Microsoft Academic Search

E. Keeler Company and Dorr-Oliver, Inc. have joined to design, market and manufacture atmospheric fluidized-bed-fired boilers. The first contract, called Shamokin, was a 23,400 lb\\/hr unit fired with anthracite culm having a heating value of 4000 Btu\\/lb and 67% ash. The Department of Energy sponsored this plant as a demonstration project. Boiler erection is nearly complete and start-up is scheduled

A. M. Leon; D. E. McCoy

1981-01-01

243

Particle pressures in fluidized beds  

SciTech Connect

This is an experimental project to make detailed measurements of the particle pressures generated in fluidized beds. The focus lies in two principle areas: (1) the particle pressure distribution around single bubbles rising in a two-dimensional gas-fluidized bed and (2) the particle pressures measured in liquid-fluidized beds. This first year has largely been to constructing the experiments The design of the particle pressure probe has been improved and tested. A two-dimensional gas-fluidized bed has been constructed in order to measure the particle pressure generated around injected bubbles. The probe is also being adapted to work in a liquid fluidized bed. Finally, a two-dimensional liquid fluidized bed is also under construction. Preliminary measurements show that the majority of the particle pressures are generated in the wake of a bubble. However, the particle pressures generated in the liquid bed appear to be extremely small. Finally, while not directly associated with the particle pressure studies, some NERSC supercomputer time was granted alongside this project. This is being used to make large scale computer simulation of the flow of granular materials in hoppers.

Campbell, C.S.; Rahman, K.; Hu, X.; Jin, C.; Potapov, A.V.

1992-01-01

244

Application of noncatalytic gas-solid reactions for a single pellet of changing size to the modeling of fluidized-bed combustion of coal char containing sulfur  

SciTech Connect

A mechanistic model is developed for coal char combustion, with sulfur retention by limestone or dolomite sorbent, in a gas fluidized bed employing noncatalytic single pellet gas-solid reactions. The shrinking core model is employed to describe the kinetics of chemical reactions taking place on a single pellet; changes in pellet size as the reaction proceeds are considered. The solids are assumed to be in back-mix condition whereas the gas flow is regarded to be in plug flow. Most char combustion occurs near the gas distributor plate (at the bottom of the bed), where the bubbles are small and consequently the mass transfer rate is high. For such a case, the analysis is considerably simplified by ignoring the bubble phase since it plays an insignificant role in the overall rate of carbon conversion. Bubble-free operation is also encounterd in the turbulent regime, where the gas flow is quite high and classical bubbles do not exist. Formulation of the model includes setting up heat and mass balance equations pertaining to a single particle (1) exposed to a varying reactant concentration along the height of the bed and (2) whose size changes during reaction. These equations are then solved numerically to account for particles of all sizes in the bed in obtaining the overall carbon conversion efficiency and resultant sulfur retention. In particular, the influence on sorbent requirement of several fluid-bed variables such as oxygen concentration profile, particle size, reaction rate for sulfation reaction, and suflur adsorption efficiency are examined.

Rehmat, A.; Saxena, S.C.; Land, R.H.

1980-09-01

245

Pressurized fluidized-bed combustion  

SciTech Connect

The US DOE pressurized fluidized bed combustion (PFBC) research and development program is designed to develop the technology and data base required for the successful commercialization of the PFBC concept. A cooperative program with the US, West Germany, and the UK has resulted in the construction of the 25 MWe IEA-Grimethorpe combined-cycle pilot plant in England which will be tested in 1981. A 13 MWe coal-fired gas turbine (air cycle) at Curtis-Wright has been designed and construction scheduled. Start-up is planned to begin in early 1983. A 75 MWe pilot plant is planned for completion in 1986. Each of these PFBC combined-cycle programs is discussed. The current status of PFB technology may be summarized as follows: turbine erosion tolerance/hot gas cleanup issues have emerged as the barrier technology issues; promising turbine corrosion-resistant materials have been identified, but long-term exposure data is lacking; first-generation PFB combustor technology development is maturing at the PDU level; however, scale-up to larger size has not been demonstrated; and in-bed heat exchanger materials have been identified, but long-term exposure data is lacking. The DOE-PFB development plan is directed at the resolution of these key technical issues. (LCL)

Not Available

1980-10-01

246

Pressurized fluidized bed reactor  

DOEpatents

A pressurized fluid bed reactor power plant includes a fluidized bed reactor contained within a pressure vessel with a pressurized gas volume between the reactor and the vessel. A first conduit supplies primary gas from the gas volume to the reactor, passing outside the pressure vessel and then returning through the pressure vessel to the reactor, and pressurized gas is supplied from a compressor through a second conduit to the gas volume. A third conduit, comprising a hot gas discharge, carries gases from the reactor, through a filter, and ultimately to a turbine. During normal operation of the plant, pressurized gas is withdrawn from the gas volume through the first conduit and introduced into the reactor at a substantially continuously controlled rate as the primary gas to the reactor. In response to an operational disturbance of the plant, the flow of gas in the first, second, and third conduits is terminated, and thereafter the pressure in the gas volume and in the reactor is substantially simultaneously reduced by opening pressure relief valves in the first and third conduits, and optionally by passing air directly from the second conduit to the turbine.

Isaksson, Juhani (Karhula, FI)

1996-01-01

247

Pressurized fluidized bed reactor  

DOEpatents

A pressurized fluid bed reactor power plant includes a fluidized bed reactor contained within a pressure vessel with a pressurized gas volume between the reactor and the vessel. A first conduit supplies primary gas from the gas volume to the reactor, passing outside the pressure vessel and then returning through the pressure vessel to the reactor, and pressurized gas is supplied from a compressor through a second conduit to the gas volume. A third conduit, comprising a hot gas discharge, carries gases from the reactor, through a filter, and ultimately to a turbine. During normal operation of the plant, pressurized gas is withdrawn from the gas volume through the first conduit and introduced into the reactor at a substantially continuously controlled rate as the primary gas to the reactor. In response to an operational disturbance of the plant, the flow of gas in the first, second, and third conduits is terminated, and thereafter the pressure in the gas volume and in the reactor is substantially simultaneously reduced by opening pressure relief valves in the first and third conduits, and optionally by passing air directly from the second conduit to the turbine. 1 fig.

Isaksson, J.

1996-03-19

248

Fluidized Bed Medium Separation (FBMS) using the particles with different hydrophilic and hydrophobic properties  

Microsoft Academic Search

Three kinds of particles with different hydrophilic and hydrophobic properties were used as fluidized particles of Fluidized Bed Medium Separation (FBMS). A minimum fluidization velocity, an apparent specific gravity of fluidized bed and floating-sinking behaviors of dry and wet coals were measured in the range of relative humidity from 50% to 80%. In a hydrophilic particle, the fluidization became unstable

Mikio Yoshida; Jun Oshitani; Keiichiro Tani; Kuniaki Gotoh

2011-01-01

249

Experimental study of radiative and particle convective heat transfer in fast fluidized beds  

Microsoft Academic Search

Circulating Fluidized Beds (CFB's) have found increasing use in such applications as fluidized catalytic cracking, coal combustion, and calcination. For the proper design, operation, and control of a circulating fluidized bed, reliable design correlations to predict the heat transfer coefficient are important. In order to determine accurately the radiative and convective heat transfer in a high temperature two-phase flow heat

Han; Gui-Young

1992-01-01

250

Environmental assessment of solid residues from fluidized-bed fuel processing. [192 references  

Microsoft Academic Search

This report presents results for the first 15 months of an environmental assessment of the solid residues generated by fluidized-bed coal combustion and oil gasification. Tasks included a literature search, chemical and physical residue characterization, laboratory leaching studies, and testing of residues in various materials and agricultural applications. The literature search reviewed current fluidized-bed combustion technology, identified products in which

R. Stone; R. Kahle

1977-01-01

251

Development Program on Pressurized Fluidized-Bed Combustion. Quarterly Report, October 1, 1974--January 1, 1975.  

National Technical Information Service (NTIS)

A development program on pressurized fluidized-bed combustion is being carried out in a bench-scale pilot plant capable of operating at 10 atm pressure. The concept involves burning fuels such as coal in a fluidized bed of particulate lime solids that rea...

G. J. Vogel P. T. Cunningham W. Hubble J. Lenc J. Montagna

1975-01-01

252

Description, applications and numerical modelling of bubbling fluidized bed combustion in waste-to-energy plants  

Microsoft Academic Search

The use of the fluidized bed combustor (FBC) has increased. It began in the 20th century as coal combustion and gasification, which then developed into catalytic reactions. Only recently, the application field has been extended to the incineration of biomass and pre-treated waste, for either power generation or waste disposal. The success of fluidized bed combustion is due to high

S. Ravelli; A. Perdichizzi; G. Barigozzi

2008-01-01

253

Refractory experience in circulating fluidized bed combustors, Task 7  

SciTech Connect

This report describes the results of an investigation into the status of the design and selection of refractory materials for coal-fueled circulating fluidized-bed combustors. The survey concentrated on operating units in the United States manufactured by six different boiler vendors: Babcock and Wilcox, Combustion Engineering, Foster Wheeler, Keeler Dorr-Oliver, Pyropower, and Riley Stoker. Information was obtained from the boiler vendors, refractory suppliers and installers, and the owners/operators of over forty units. This work is in support of DOE's Clean Coal Technology program, which includes circulating fluidized-bed technology as one of the selected concepts being evaluated.

Vincent, R.Q.

1989-11-01

254

Second-Generation Pressurized Fluidized Bed Combustion: Small gas turbine induustrial plant study  

SciTech Connect

Second-Generation Pressurized Fluidized Bed Combustion (PFBC) plants provide a coal-fired, high-efficiency, combined-cycle system for the generation of electricity and steam. The plants use lime-based sorbents in PFB combustors to meet environmental air standards without back-end gas desulfurization equipment. The second-generation system is an improvement over earlier PFBC concepts because it can achieve gas temperatures of 2100[degrees]F and higher for improved cycle efficiency while maintaining the fluidized beds at 1600[degrees]F for enhanced sulfur capture and minimum alkali release. Second-generation PFBC systems are capable of supplying the electric and steam process needs of industrial plants. The basic second-generation system can be applied in different ways to meet a variety of process steam and electrical requirements. To evaluate the potential of these systems in the industrial market, conceptual designs have been developed for six second-generation PFBC plants. These plants cover a range of electrical outputs from 6.3 to 41.5 MWe and steam flows from 46,067 to 442,337 lb/h. Capital and operating costs have been estimated for these six plants and for equivalent (in size) conventional, coal-fired atmospheric fluidized bed combustion cogeneration plants. Economic analyses were conducted to compare the cost of steam for both the second-generation plants and the conventional plants.

Shenker, J.; Garland, R.; Horazak, D.; Seifert, F.; Wenglarz, R.

1992-07-01

255

Second-Generation Pressurized Fluidized Bed Combustion: Small gas turbine industrial plant study  

SciTech Connect

Second-Generation Pressurized Fluidized Bed Combustion (PFBC) plants provide a coal-fired, high-efficiency, combined-cycle system for the generation of electricity and steam. The plants use lime-based sorbents in PFB combustors to meet environmental air standards without back-end gas desulfurization equipment. The second-generation system is an improvement over earlier PFBC concepts because it can achieve gas temperatures of 2100{degrees}F and higher for improved cycle efficiency while maintaining the fluidized beds at 1600{degrees}F for enhanced sulfur capture and minimum alkali release. Second-generation PFBC systems are capable of supplying the electric and steam process needs of industrial plants. The basic second-generation system can be applied in different ways to meet a variety of process steam and electrical requirements. To evaluate the potential of these systems in the industrial market, conceptual designs have been developed for six second-generation PFBC plants. These plants cover a range of electrical outputs from 6.3 to 41.5 MWe and steam flows from 46,067 to 442,337 lb/h. Capital and operating costs have been estimated for these six plants and for equivalent (in size) conventional, coal-fired atmospheric fluidized bed combustion cogeneration plants. Economic analyses were conducted to compare the cost of steam for both the second-generation plants and the conventional plants.

Shenker, J.; Garland, R.; Horazak, D.; Seifert, F.; Wenglarz, R.

1992-07-01

256

Coal Pyrolysis by Hot Solids from a Fluidized Bed Combustor. Quarterly Progress Report, June 1, 1977--August 31, 1977.  

National Technical Information Service (NTIS)

The design, construction and testing of the experimental apparatus has been completed. Several modifications in the experimental apparatus have resulted in a system that gives very good material balances for non-caking coals. (ERA citation 03:030107)

G. Alexander J. B. Howard J. P. Longwell J. Nwalor W. A. Peters

1977-01-01

257

Four Rivers second generation Pressurized Circulating Fluidized Bed Combustion Project  

Microsoft Academic Search

Air Products has been selected in the DOE Clean Coal Technology Round V program to build, own, and operate the first commercial power plant using second generation Pressurized Circulating Fluidized Bed (PCFB) combustion technology. The four Rivers Energy Project (Four Rivers) will produce up to 400,000 lb\\/hr steam, or an equivalent gross capacity of 95 MWe. The unit will be

E. P. Holley; J. J. Lewnard; G. von Wedel; K. W. Richardson; H. T. Morehead

1995-01-01

258

Apparatus and process for controlling fluidized beds  

DOEpatents

An apparatus and process for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance.

Rehmat, Amirali G. (Westmont, IL); Patel, Jitendra G. (Bolingbrook, IL)

1985-10-01

259

Fluidized-Bed Reactor System  

NASA Technical Reports Server (NTRS)

Gas pyrolysis in hot fluidized beds minimized by use of selectively filtered radiation and parabolic cavity. Reactor is parabolic cavity of two or more axes in which light emanating from one axis bounces off walls of cavity and passes through object axis to heat sample.

Morrison, A. D.

1985-01-01

260

Fluidized-bed combustion fuel  

Microsoft Academic Search

This patent describes a process for producing from a solid carbonaceous refuse a high ash fuel for use in a circulating fluidized-bed combustion chamber. It comprises separating from the refuse a carbonaceous portion having an ash content in a selected range percent by weight; separating the carbonaceous portion into first and second fractions, the first fraction being at or above

Rich; J. W. Jr

1990-01-01

261

Fluidized bed: Meeting the challenges  

Microsoft Academic Search

Biomass is widely used as a fuel for fluidized bed boilers. Extending the technology's reach to include municipal solid waste is proving to be more challenging. For several years, the city of Robbins, Ill., has been the site for a proposed waste-to-energy facility. Reading Energy Co. of Philadelphia, Pa., has attained permits for what is expected to be the United

2009-01-01

262

Atmospheric fluidized bed combustion advanced system concepts applicable to small industrial and commercial markets. Topical report, Level 2.  

National Technical Information Service (NTIS)

As part of an overall strategy to promote FBC coal combustion and to improve the marketability of the eastern coals, the US Department of Energy's Morgantown Energy Research Center awarded a three level contract to Riley Stoker Corporation to develop adva...

T. R. Ake V. B. Dixit R. K. Mongeon

1992-01-01

263

Multicell fluidized-bed boiler design, construction and test program. Interim report, July 1974June 1975  

Microsoft Academic Search

Design, construction and test program of a 300,000 lbs\\/hr steam generation capacity multicell fluidized-bed boiler (MFB), as a pollution-free method of burning high-sulfur coal, or highly corrosive coals without excessive problems, is being carried out. The concept involves burning fuels, such as coal, in a fluidized-bed of limestone particles that react with the sulfur compounds formed during combustion, to reduce

J. E. Mesko; R. R. Reed; J. Malik; R. L. Gamble; F. R. Warshany

1975-01-01

264

Industrial Application of Fluidized Bed Combustion. Progress Report, January-September 1983.  

National Technical Information Service (NTIS)

Work accomplished during a shut-down of the industrial fluidized bed (IFB) plant is reported, including: coal receiving and preparation; fuel feed system work; progress on boiler and gas side equipment. After completion of construction work and acid clean...

1983-01-01

265

TRACE AND MINOR ELEMENT REACTIONS IN FLUIDIZED-BED COMBUSTION PROCESSES  

EPA Science Inventory

The report gives results of thermodynamic equilibrium calculations for anticipated operating ranges for various fluidized-bed combustion (FBC) designs used to predict the potential volatility and interaction of 31 trace and minor elements contained in coal and sorbent feedstocks....

266

Spectral Dynamics of Computer Simulated Two-Dimensional Fewtube Fluidized Beds.  

National Technical Information Service (NTIS)

Fluidized bed combustion technology attracts intense commercial interest for its capability of burning high-sulfur coal in a more economic and environmentally acceptable manner, despite the unsolved erosion problem. Detailed knowledge of the complex pheno...

S. L. Chang R. W. Lyczkowski G. F. Berry

1989-01-01

267

Novel Magnetically Fluidized Bed Reactor Development for the Looping Process: Coal to Hydrogen Production R&D  

SciTech Connect

The coal to hydrogen project utilizes the iron/iron oxide looping process to produce high purity hydrogen. The input energy for the process is provided by syngas coming from gasification process of coal. The reaction pathways for this process have been studied and favorable conditions for energy efficient operation have been identified. The Magnetically Stabilized Porous Structure (MSPS) is invented. It is fabricated from iron and silica particles and its repeatable high performance has been demonstrated through many experiments under various conditions in thermogravimetric analyzer, a lab-scale reactor, and a large scale reactor. The chemical reaction kinetics for both oxidation and reduction steps has been investigated thoroughly inside MSPS as well as on the surface of very smooth iron rod. Hydrogen, CO, and syngas have been tested individually as the reducing agent in reduction step and their performance is compared. Syngas is found to be the most pragmatic reducing agent for the two-step water splitting process. The transport properties of MSPS including porosity, permeability, and effective thermal conductivity are determined based on high resolution 3D CT x-ray images obtained at Argonne National Laboratory and pore-level simulations using a lattice Boltzmann Equation (LBE)-based mesoscopic model developed during this investigation. The results of those measurements and simulations provide necessary inputs to the development of a reliable volume-averaging-based continuum model that is used to simulate the dynamics of the redox process in MSPS. Extensive efforts have been devoted to simulate the redox process in MSPS by developing a continuum model consist of various modules for conductive and radiative heat transfer, fluid flow, species transport, and reaction kinetics. Both the Lagrangian and Eulerian approaches for species transport of chemically reacting flow in porous media have been investigated and verified numerically. Both approaches lead to correct prediction of hydrogen production rates over a large range of experimental conditions in the laboratory scale reactor and the bench-scale reactor. In the economic analysis, a comparison of the hydrogen production plants using iron/iron oxide looping cycle and the conventional process has been presented. Plant configurations are developed for the iron/iron oxide looping cycle. The study suggests a higher electric power generation but a lower hydrogen production efficiency comparing with the conventional process. Additionally, it was shown that the price of H{sub 2} obtained from our reactor can be as low as $1.7/kg, which is 22% lower than the current price of the H{sub 2} obtained from reforming plants.

Mei, Renwei; Hahn, David; Klausner, James; Petrasch, Jorg; Mehdizadeh, Ayyoub; Allen, Kyle; Rahmatian, Nima; Stehle, Richard; Bobek, Mike; Al-Raqom, Fotouh; Greek, Ben; Li, Like; Chen, Chen; Singh, Abhishek; Takagi, Midori; Barde, Amey; Nili, Saman

2013-09-30

268

Fluidized bed desulfurization  

NASA Technical Reports Server (NTRS)

High sulfur content carbonaceous material, such as coal is desulfurized by continuous fluidized suspension in a reactor with chlorine gas, inert dechlorinating gas and hydrogen gas. A source of chlorine gas, a source of inert gas and a source of hydrogen gas are connected to the bottom inlet through a manifold and a heater. A flow controler operates servos in a manner to continuously and sequentially suspend coal in the three gases. The sulfur content is reduced at least 50% by the treatment.

Ravindram, M.; Kallvinskas, J. J. (inventors)

1985-01-01

269

Capacitively-Heated Fluidized Bed  

NASA Technical Reports Server (NTRS)

Fluidized-bed chamber in which particles in bed are capacitively heated produces high yields of polycrystalline silicon for semiconductor devices. Deposition of unrecoverable silicon on chamber wall is reduced, and amount of recoverable silicon depositing on seed particles in bed is increased. Particles also have a size and density suitable for direct handling without consolidation, unlike silicon dust produced in heated-wall chambers.

Mchale, E. J.

1982-01-01

270

Cold slumping characteristics of a fluidized bed  

SciTech Connect

Cold slumping tests were performed on a 4 x 4 Plexiglas model of the TVA 20-MW atmospheric fluidized bed combustion pilot plant. The tests were conducted to determine mixing between the active and slumped sections, fluidizing air bypass through the slumped section, elutriation from the fluidized section, and maximum buildup in the slumped section. With an 18-in. bed depth and a mean particle size of 370 ..mu..m, the average superficial velocity in the slumped section was approximately one-half of the minimum fluidizing velocity. The maximum buildup in the slumped section was approx. 35% of the bed static depth. The elutriation from the active bed resulted in a decrease of approx. 20% in the static bed height. The potential oxidizing-reducing condition at the interface of the slumped and fluidized bed sections as well as the chance of crusting the slumped section may be prevented by supplying air to the windboxes of the slumped sections. It is recommended that this approach be allowed for in the design of the pilot plant by the installation of the equipment required to meter the air flow to the windbox of each bed section that can be slumped. The approximate air-metering range should be from 25 to 110% of air required for minimum fluidization of the section.

Lackey, M.E.

1980-09-01

271

Fluidized-Bed Reactor With Zone Heating  

NASA Technical Reports Server (NTRS)

Deposition of silicon on wall suppressed. In new fluidized bed, silicon seed particles heated in uppermost zone of reactor. Hot particles gradually mix with lower particles and descend through fluidized bed. Lower wall of vessel kept relatively cool. Because silane enters at bottom and circulates through reactor pyrolized to silicon at high temperatures, silicon deposited on particles in preference wall. Design of fluidized bed for production of silicon greatly reduces tendency of silicon to deposit on wall of reaction vessel.

Iya, Sridhar K.

1989-01-01

272

COSTS FOR ADVANCED COAL COMBUSTION TECHNOLOGIES  

EPA Science Inventory

The report gives results of an evaluation of the development status of advanced coal combustion technologies and discusses the preparation of performance and economic models for their application to electric utility plants. he technologies addressed were atmospheric fluidized bed...

273

Fluidized bed regenerators for Brayton cycles  

NASA Technical Reports Server (NTRS)

A recuperator consisting of two fluidized bed regenerators with circulating solid particles is considered for use in a Brayton cycle. These fluidized beds offer the possibility of high temperature operation if ceramic particles are used. Calculations of the efficiency and size of fluidized bed regenerators for typical values of operating parameters were made and compared to a shell and tube recuperator. The calculations indicate that the fluidized beds will be more compact than the shell and tube as well as offering a high temperature operating capability.

Nichols, L. D.

1975-01-01

274

Fluidized bed regenerators for Brayton cycles  

NASA Technical Reports Server (NTRS)

A recuperator consisting of two fluidized bed regenerators with circulating solid particles is considered for use in a Brayton cycle. These fluidized beds offer the possibility of high temperature operation if ceramic particles are used. Calculations of the efficiency and size of fluidized bed regenerators for typical values of operating parameters have been made and compared to a shell and tube recuperator. The calculations indicate that the fluidized beds will be more compact than the shell and tube as well as offering a high temperature operating capability.

Nichols, L. D.

1975-01-01

275

Reduction of particulate carryover from a pressurized fluidized bed  

NASA Technical Reports Server (NTRS)

A bench-scale pressurized fluidized bed combustor (PFBC) constructed with a conical shape to reduce the particulate carryover is examined. The combustor was fed coal and limestone with the coal to air ratio varying from 0.033 to 0.098 (all lean) and the coal to limestone ratio varying from 0.06 to 0.36. Two cone angles were used and it is shown that the average particulate carryover of 2.5 grains/SCF is appreciably less than cylindrical fluidized bed combustors. In addition the carryover was correlated by multiple regression analysis to yield the dependence on bed depth and hence the collection efficiency, which was 20%. Finally, a comparison with a model indicated that the exhaust port may be below the transport disengaging height for most of the tests showing that further improvements could be achieved by increasing the freeboard height of the exhaust port above the bed.

Patch, R. W.

1979-01-01

276

Engineer, design, construct, test, and evaluate a pressurized fluidized-bed pilot plant using high-sulfur coal for production of electric power: Phase III. Pilot plant construction. Quarterly report, March 1-May 31, 1981  

SciTech Connect

Progress in Phase III of the Engineering Program to design, construct, test and evaluate a pressurized fluidized bed pilot plant is reported. Phase III includes pilot plant fabrication, construction and initial check out. Fabrication of the upper and lower PFB combustor vessels is being followed by a short interval schedule and delivery is projected for July 15, 1981. Fabrication of component parts of the combustor recycle loop is on schedule. The recycle cyclone, freeboard tee, recycle cyclone tee, trickle valve and upper spool piece have all been received for the installation of refractory lining. The bellows assembly is scheduled for completion on July 15, 1981. Material handling equipment purchase orders were placed for the coal handling equipment, electric elevator, coal preparation, and ash handling equipment. Fire protection specifications were issued. The overall project is 43% complete. (LCL)

Not Available

1981-01-01

277

Fluidized-Bed Combustion Test of Low-Quality Fuels. I. Anthracite Refuse.  

National Technical Information Service (NTIS)

A total of five types of anthracite refuse material with widely different characteristics have been successfully burned in the 18-inch diameter atmospheric pressure fluidized-bed combustor at the Morgantown Energy Research Center of the Energy Research an...

J. S. Mei R. L. Gall J. S. Wilson

1977-01-01

278

Regeneration of Calcium-Based SO2 Sorbents for Fluidized-Bed Combustion: Engineering Evaluation.  

National Technical Information Service (NTIS)

The report gives results of an engineering evaluation of regeneration of calcium-based SO2 sorbents (limestone and dolomite) for application in both atmospheric and pressurized fluidized-bed combustion (FBC) processes. Economics of FBC power plants, opera...

R. A. Newby S. Katta D. L. Keairns

1978-01-01

279

Fluidized bed deposition of diamond  

DOEpatents

A process for coating a substrate with diamond or diamond-like material including maintaining a substrate within a bed of particles capable of being fluidized, the particles having substantially uniform dimensions and the substrate characterized as having different dimensions than the bed particles, fluidizing the bed of particles, and depositing a coating of diamond or diamond-like material upon the substrate by chemical vapor deposition of a carbon-containing precursor gas mixture, the precursor gas mixture introduced into the fluidized bed under conditions resulting in excitation mechanisms sufficient to form the diamond coating.

Laia, Jr., Joseph R. (Los Alamos, NM); Carroll, David W. (Los Alamos, NM); Trkula, Mitchell (Los Alamos, NM); Anderson, Wallace E. (Los Alamos, NM); Valone, Steven M. (Santa Fe, NM)

1998-01-01

280

Staged cascade fluidized bed combustor  

DOEpatents

A fluid bed combustor comprising a plurality of fluidized bed stages interconnected by downcomers providing controlled solids transfer from stage to stage. Each stage is formed from a number of heat transfer tubes carried by a multiapertured web which passes fluidizing air to upper stages. The combustor cross section is tapered inwardly from the middle towards the top and bottom ends. Sorbent materials, as well as non-volatile solid fuels, are added to the top stages of the combustor, and volatile solid fuels are added at an intermediate stage.

Cannon, Joseph N. (4103 Farragut St., Hyattsville, MD 20781); De Lucia, David E. (58 Beacon St., Apt. No. 2, Boston, MA 02108); Jackson, William M. (5300 McArthur Blvd., NW., Washington, DC 20016); Porter, James H. (P.O. Box 1131, Daggett Ave., Vineyard Haven, MA 02568)

1984-01-01

281

Repowering with pressurized fluidized-bed combustion units  

Microsoft Academic Search

Turbocharged pressurized fluidized bed combustion (PFBC) power plants operating with a gas turbine inlet temperature lower than 800°F can produce electricity more efficiently (34.2 vs. 33.5% net plant efficiency) and at a lower cost of electricity (87.8 vs. 96. 6 mill\\/kWh over 30 years) than conventional pulverized-coal-fired plants with scrubbers. Since the PFBC process produces lower NOâ emissions than conventional

S. J. Goidich; L. N. Rubow; S. Kumar; D. Mukherjee; N. B. Childress

1991-01-01

282

Four Rivers second generation Pressurized Circulating Fluidized Bed Combustion Project  

SciTech Connect

Air Products has been selected in the DOE Clean Coal Technology Round V program to build, own, and operate the first commercial power plant using second generation Pressurized Circulating Fluidized Bed (PCFB) combustion technology. The four Rivers Energy Project (Four Rivers) will produce up to 400,000 lb/hr steam, or an equivalent gross capacity of 95 MWe. The unit will be used to repower an Air Products chemicals manufacturing facility in Calvert City, Kentucky.

Holley, E.P.; Lewnard, J.J. [Air Products and Chemicals, Inc. (United States); von Wedel, G. [LLB Lurgi Lentjes Babcock Energietechnik (GmbH); Richardson, K.W. [Foster Wheeler Energy Corp. (United States); Morehead, H.T. [Westinghouse Electric Corp. (United States)

1995-04-01

283

Heat transfer to horizontal tubes immersed in a fluidized-bed combustor  

Microsoft Academic Search

Experiments were carried out to measure the heat transfer rates to water-cooled horizontal tubes immersed in an atmospheric fluidized-bed combustor burning North Dakota lignite. The effect of bed temperature (T\\/sub BETA\\/ = 587-1205K), particle size (d\\/sub rho\\/ = 0.544-2,335 mm), and fluidizing velocity (U = 0.73-2.58 m\\/s) on heat transfer rate to horizontal tubes immersed in a fluidized-bed combustor (0.45

N. S. Grewal; J. Menart; D. R. Hajicek; B. J. Zobeck

1987-01-01

284

Advanced development of a pressurized ash agglomerating fluidized-bed coal gasification system: Phase 2, Final report, May 1, 1983-July 31, 1984  

SciTech Connect

KRW Energy Systems Inc. is engaged in the development of a pressurized, fluidized-bed, gasification process at its Waltz Mill Site in Madison, Pennsylvania. The overall objective of the program is to demonstrate the viability of the KRW process for the environmentally acceptable production of low- and medium-Btu fuel gas from a variety of fossilized, carbonaceous feedstocks for electrical power generation, substitute natural gas, chemical feedstocks, and industrial fuels. This report covers Phase II of the contract period (May 1, 1983 to July 31, 1984) and is a continuation of the work performed in 1983 and reported in the Phase I final report, FE-19122-30. Included is work performed in fiscal 1983 to 1984 on PDU testing, process analysis, cold flow scaleup facility, process and component engineering and design, and laboratory support studies.

None

1987-09-15

285

Enhanced durability of desulfurization sorbents for fluidized-bed applications  

SciTech Connect

Advanced integrated gasification combined cycle (IGCC) power systems require the development of high-temperature desulfurization sorbents capable of removing hydrogen sulfide from coal gasifier down to very low levels. The objective of this investigation was to identify and demonstrate methods for enhancing the long-term chemical reactivity and mechanical strength of zinc ferrite, a leading regenerable sorbent, for fluidized-bed applications. Fluidized sorbent beds offer significant potential in IGCC systems because of their ability to control the highly exothermic regeneration involved. However, fluidized beds require a durable, attrition-resistant sorbent in the 100--300 {mu}m size range. A bench-scale high-temperature, high- pressure (HTHP) fluidized-bed reactor (7.6-cm I.D.) system capable of operating up to 24 atm and 800{degree}C was designed, built and tested. A total of 175 sulfidation-regeneration cycles were carried out using KRW-type coal gas with various zinc ferrite formulations. A number of sorbent manufacturing techniques including spray drying, impregnation, crushing and screening, and granulation were investigated. While fluidizable sorbents prepared by crushing durable pellets and screening had acceptable sulfur capacity, they underwent excessive attrition during multicycle testing. The sorbent formulations prepared by a proprietary technique were found to have excellent attrition resistance and acceptable chemical reactivity during multicycle testing. However, zinc ferrite was found to be limited to 550{degree}C, beyond which excessive sorbent weakening due to chemical transformations, e.g., iron oxide reduction, was observed.

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

1991-06-01

286

Fluidized-bed combustion fuel  

SciTech Connect

This patent describes a process for producing from a solid carbonaceous refuse a high ash fuel for use in a circulating fluidized-bed combustion chamber. It comprises separating from the refuse a carbonaceous portion having an ash content in a selected range percent by weight; separating the carbonaceous portion into first and second fractions, the first fraction being at or above a selected size; crushing the first fraction; and combining the crushed first fraction with the second fraction. Also described is a process wherein the selected ash content range is between about 30 percent and about 50 percent, by weight. Also described is a process wherein the selected size is above about 1/4 inch.

Rich, J.W. Jr.

1990-10-09

287

Investigation of fluidized-bed biological denitrification  

SciTech Connect

The performance of the fluidized-bed bioreactor was modelled for denitrification using a multiple linear regression. Reasonable accuracy was obtained; however, this type of analysis did not take into account the hydraulic characteristics of the fluidized-bed. The Mulcahy and LaMotta computer program previously used to model a fluidized-bed bioreactor cannot be used in this case due to the Michaelis-Menton constant k determined in this study, which was one to two orders of magnitude lower. With some additional bioreactor study and computer program modification, this may prove to be of some benefit.

Acox, T.A.

1982-12-16

288

Combustion of waste fuels in a fluidized-bed boiler  

Microsoft Academic Search

This paper reports on a project whose objectives are to determine the impact of the waste fuels on Atmospheric Fluidized Bed Combustion (AFBC) operating procedures, boiler performance, and emissions and to assess the potential for fuel-specific operating problems. The low-grade waste fuels investigated are hogged railroad ties, shredded rubber tires, peat, refuse-derived fuel, and one or more agricultiral wastes. The

J. Zylkowski; S. Ehrlich

1983-01-01

289

Local solid mixing in gas–solid fluidized beds  

Microsoft Academic Search

Diffusivity of the solid particles in a 152-mm ID gas–solid fluidized bed was determined at different regimes of fluidization. The gas was air at room temperature and atmospheric pressure and the solids were 385 ?m sand or 70 ?m FCC particles. The experiments were done at superficial gas velocities from 0.5 to 2.8 m\\/s for sand and 0.44 to 0.9

Navid Mostoufi; Jamal Chaouki

2001-01-01

290

Simulation of a Circulating Fluidized Bed Combustor with Shrinking Core and Emission Models  

Microsoft Academic Search

A Circulating Fluidized Bed Combustor (CFBC) is a highly efficient combustor. It can handle various types of solid fuels such as coal, biomass or agricultural wastes. Coal and biomass have been used as fuel to generate heat for a boiler in many industries. To predict the proper amount of mixed fuel and to reduce the emission from coal burning, a

Natthapong Ngampradit; Pornpote Piumsomboon; Boonrod Sajjakulnukit

291

Disposal of fluidized bed combustion ash in an underground mine to control acid mine drainage and subsidence.  

National Technical Information Service (NTIS)

This project will evaluate the technical, economic and environmental feasibility of filling abandoned underground mine voids with alkaline, advanced coal combustion wastes (Fluidized Bed Combustion-FBC ash). Success will be measured in terms of technical ...

2000-01-01

292

Modular integrated fluidized bed bioreactor technology.  

PubMed

We describe the design and demonstrate the application of a modular integrated fluidized bed bioreactor system. Basically the system is a reactor vessel equipped with an extending cylinder and a liquid distributor plate. Instead of an external recirculation loop, as used in existing fluidized bed systems, a low shear stress impeller is used as the recirculation pump. The system has several unique features, such as modular exchangeable elements, efficient oxygenation and the option of operating as a stirred tank-, a packed bed- or a fluidized bed reactor. An example of a fluidized bed run using CHO-K1 cells is shown. Under standard culture conditions a 100-fold increase in cell density (up to 1.2 x 10(8) cells/ml) was achieved. PMID:1367626

Reiter, M; Blüml, G; Gaida, T; Zach, N; Unterluggauer, F; Doblhoff-Dier, O; Noe, M; Plail, R; Huss, S; Katinger, H

1991-11-01

293

Technology Overview: Circulating Fluidized-Bed Combustion.  

National Technical Information Service (NTIS)

The report summarizes the current technical status of circulating fluidized-bed combustion (CFBC). Companies that are involved in investigating this technology and/or developing commercial systems are discussed, along with system descriptions and availabl...

D. R. Roeck

1982-01-01

294

Drying of solids in fluidized beds  

SciTech Connect

Fluidized bed drying is advantageously adopted in industrial practice for drying of granular solids such as grains, fertilizers, chemicals, and minerals either for long shelf life or to facilitate further processing or handling. Solids are dried in batch and in continuous fluidized beds corresponding to cross-flow and countercurrent flow of phases covering a wide range in drying conditions. Materials that essentially dry with constant drying rate and then give a falling drying rate approximately linear with respect to solids moisture content (sand) as well as those with an extensive falling rate period with the subsequent falling rate being a curve with respect to the moisture content (mustard, ragi, poppy seeds) are chosen for the study. The performance of the continuous fluidized bed driers is compared with that of batch fluidized bed driers; the performance is predicted using batch kinetics, the residence time distribution of solids, and the contact efficiency between the phases.

Kannan, C.S.; Thomas, P.P.; Varma, Y.B.G. [Indian Inst. of Tech., Madras (India). Dept. of Chemical Engineering

1995-09-01

295

Fluidized-Bed Combustion Technology Overview.  

National Technical Information Service (NTIS)

The report reviews fluidized-bed combustion (FBC) technology development through 1979, specifying the work of governmental agencies and individual investigators, highlighting key technical issues, and documenting the current degree of FBC commercializatio...

T. E. Dowdy M. G. Klett L. N. Rubow R. G. Seth J. O. Milliken

1981-01-01

296

TECHNOLOGY OVERVIEW: CIRCULATING FLUIDIZED-BED COMBUSTION  

EPA Science Inventory

The report summarizes the current technical status of circulating fluidized-bed combustion (CFBC). Companies that are involved in investigating this technology and/or developing commercial systems are discussed, along with system descriptions and available cost information. CFBC ...

297

Use of Glow Discharge in Fluidized Beds.  

National Technical Information Service (NTIS)

Static charges and agglomeration of particles in a fluidized bed system are minimized by maintaining in at least part of the bed a radio frequency glow discharge. This approach is eminently suitable for processes in which the conventional charge removing ...

T. Wydeven P. C. Wood E. V. Ballou L. A. Spitze

1979-01-01

298

Chemicothermal treatment of gears in fluidized bed  

Microsoft Academic Search

1.The fatigue and static strengths of steel 12KhN3A after carburizing and tempering in fluidized bed are the same as those resulting from the existing treatment, while the wear resistance is higher.2.Rapid heat treatment of gears in fluidized bed (carburizing to a depth of 1.2–1.3 mm at 950° for 2.5 h; high-temperature tempering at 650° for 3 h; quenching from 820°,

T. A. Pumpyanskaya; V. A. Vinokurov; A. P. Baskakov; E. N. Myadzelets

1975-01-01

299

Bed material agglomeration during fluidized bed combustion. Technical progress report, January 1, 1995--March 31, 1995  

SciTech Connect

Experiments performed support the hypothesis that a reducing atmosphere during fluidized bed coal combustion contributes to the formation of agglomerates. Reducing conditions are imposed by controlling the amount of combustion air supplied to the combustor, 50% of theoretical in these experiments. These localized reducing conditions may arise from either poor lateral bed mixing or oxygen-starved conditions due to the coal feed locations. Deviations from steady-state operating conditions in bed pressure drop may be used to detect agglomerate formation. Interpretation of the bed pressure drop was made more straightforward by employing a moving average difference method. During steady-state operation, the difference between the moving point averages should be close to zero, within {plus_minus}0.03 inches of water. Instability within the combustor, experienced once agglomerates begin to form, can be recognized as larger deviations from zero, on the magnitude of {plus_minus}0.15 inches of water.

Brown, R.C.; Dawson, M.R.; Smeenk, J.L.

1995-04-01

300

Industrial application of fluidized-bed cogeneration system  

SciTech Connect

In recent years development work and pilot-plant studies into the concept of fluidized-bed combustion (FBC) have given way to ever larger and more ambitious commercial projects. This technology moved rapidly from the laboratory into industrial application due to its two primary advantages: 1) the ability to burn low-grade inexpensive fuel; and 2) to burn it in an environmentally acceptable manner. In a major contribution to its commercialization, Shell Nederland Raffinadeij (SNR) awarded a contract to Foster Wheeler (FW) for the design, fabrication and erection management of the world's first commercial cogeneration, coalfired atmospheric fluidized-bed boiler capable of generating superheated steam. The fluidized-bed steam generator facility is located at the SNR's Europoort Tank Farm near Rotterdam in the Netherlands. It is designed as a cogeneration facility in which high-pressure steam passes to a back-pressure turbine which generates 6.6 MW of electricity, Figure 1. The 710 kPa (103 psig) back-pressure steam is then fed to twin heat exchangers, which provide 37 MW of thermal heat energy via mediumpressure hot water to satisfy the heat demand of the tank farm. This article describes the design of the steam generator and subsystems, as well as the modifications of the previous units' designs done to improve performance and reliability.

Kelly, W.R.; Mullin, D.E.; Rourke, D.M.

1984-01-01

301

Multicell Fluidized-Bed Boiler Design, Construction and Test Program. Interim Report, July 1974--June 1975.  

National Technical Information Service (NTIS)

Design, construction and test program of a 300,000 lbs/hr steam generation capacity multicell fluidized-bed boiler (MFB), as a pollution-free method of burning high-sulfur coal, or highly corrosive coals without excessive problems, is being carried out. T...

J. E. Mesko R. R. Reed J. Malik R. L. Gamble F. R. Warshany

1975-01-01

302

Multicell Fluidized-Bed Boiler Design, Construction and Test Program. Monthly Progress Status Report No. 56.  

National Technical Information Service (NTIS)

The design, construction and test program of a 300,000 lbs/hr steam generation capacity multicell fluidized-bed boiler (MFB), as a pollution-free method of burning high-sulfur coal, or highly corrosive coals without excessive problems, is being carried ou...

J. E. Mesko

1977-01-01

303

Refractory experience in circulating fluidized bed combustors, Task 7. Final report  

SciTech Connect

This report describes the results of an investigation into the status of the design and selection of refractory materials for coal-fueled circulating fluidized-bed combustors. The survey concentrated on operating units in the United States manufactured by six different boiler vendors: Babcock and Wilcox, Combustion Engineering, Foster Wheeler, Keeler Dorr-Oliver, Pyropower, and Riley Stoker. Information was obtained from the boiler vendors, refractory suppliers and installers, and the owners/operators of over forty units. This work is in support of DOE`s Clean Coal Technology program, which includes circulating fluidized-bed technology as one of the selected concepts being evaluated.

Vincent, R.Q.

1989-11-01

304

Utilization of ventilation air methane as a supplementary fuel at a circulating fluidized bed combustion boiler.  

PubMed

Ventilation air methane (VAM) accounts for 60-80% of the total emissions from coal mining activities in China, which is of serious greenhouse gas concerns as well as a waste of valuable fuel sources. This contribution evaluates the use of the VAM utilization methods as a supplementary fuel at a circulating fluidized bed combustion boiler. The paper describes the system design and discusses some potential technical challenges such as methane oxidation rate, corrosion, and efficiency. Laboratory experimentation has shown that the VAM can be burnt completely in circulated fluidized bed furnaces, and the VAM oxidation does not obviously affect the boiler operation when the methane concentration is less than 0.6%. The VAM decreased the incomplete combustion loss for the circulating fluidized bed combustion furnace. The economic benefit from the coal saving insures that the proposed system is more economically feasible. PMID:18505001

You, Changfu; Xu, Xuchang

2008-04-01

305

Rivesville multicell fluidized bed boiler. Annual technical progress report. July 1978-June 1979  

SciTech Connect

Design, construction and test program of a 300,000 lb/hr steam generating capacity multicell fluidized bed boiler (MFB), as a pollution free method of burning high-sulfur or highly corrosive coals, is being carried out. The concept involves burning fuels such as coal, in a fluidized bed of limestone particles that react with the sulfur compounds formed during combustion to reduce air pollution. Nitrogen oxide emissions are also reduced at the lower combustion temperatures. The CaSO/sub 4/ produced in the furnace is discharged with the ash or regenerated to CaO for reuse in the fluidized bed. Information is presented on continued operation of the Rivesville MFB steam generating plant in a commercial mode and for determining performance and emission characteristics; studies and tests on flyash characterization and reinjection, fuel feed eductors and needles, air distributor, corrosion-erosion and sulfur capture; engineering studies to improve MFB performance and reliability.

Not Available

1980-08-01

306

COMPUTATIONAL MODELING OF CIRCULATING FLUIDIZED BED REACTORS  

SciTech Connect

Details of numerical simulations of two-phase gas-solid turbulent flow in the riser section of Circulating Fluidized Bed Reactor (CFBR) using Computational Fluid Dynamics (CFD) technique are reported. Two CFBR riser configurations are considered and modeled. Each of these two riser models consist of inlet, exit, connecting elbows and a main pipe. Both riser configurations are cylindrical and have the same diameter but differ in their inlet lengths and main pipe height to enable investigation of riser geometrical scaling effects. In addition, two types of solid particles are exploited in the solid phase of the two-phase gas-solid riser flow simulations to study the influence of solid loading ratio on flow patterns. The gaseous phase in the two-phase flow is represented by standard atmospheric air. The CFD-based FLUENT software is employed to obtain steady state and transient solutions for flow modulations in the riser. The physical dimensions, types and numbers of computation meshes, and solution methodology utilized in the present work are stated. Flow parameters, such as static and dynamic pressure, species velocity, and volume fractions are monitored and analyzed. The differences in the computational results between the two models, under steady and transient conditions, are compared, contrasted, and discussed.

Ibrahim, Essam A

2013-01-09

307

MEASUREMENTS OF IN-BED TUBE BUNDLE EROSION AND PARTICLE-TUBE COLLISION FREQUENCY IN A GAS FLUIDIZED BED  

Microsoft Academic Search

Erosion of an in-bed tube bundle by bed materials (ash, coal, and sorbents) impingement has caused serious problems to many fluidized bed combustion (FBC) boilers. Experimental investigation of the tube erosion processes was made by placing the erosion-prone wax cylinders in a bench-scale, cold fluidized bed to simulate the long term erosion effect. This paper discusses the results of systematic

S. NIEH; S. Y. Lin; S. W. LEE; T. T. FU

1988-01-01

308

Sampling and instrumentation for fluidized-bed combustion. Annual report, October 1978-September 1979  

SciTech Connect

In the first section of this report, background information is presented on instrumentation for fluidized-bed combustion, i.e., for process control, scientific investigation, and safety in planned and operating fluidized-bed combustion systems. The objective of this study is to update and extend the fluidized-bed portion of a preceding report, A Study of the State-of-the-Art of Instrumentation for Process Control and Safety in Large-Scale Coal Gasification, Liquefaction, and Fluidized-Bed Combustion Systems, ANL-76-4. The second section of this report describes two prototype mass flow rate instruments installed on the solids feed lines of an existing ANL fluidized-bed combustor. The Fossil Instrumentation Group at ANL designed, fabricated, and installed these instruments in cooperation with Chemical Engineering Division personnel - one on the coal feedline and one on the coal/limestone feedline. Each instrument consisted of a capacitive sensor spoolpiece and an associated preamplifier and signal conditioning. One channel of each instrument provides three outputs. One delivers a density signal while two others deliver two signals for measuring velocity by cross-correlation. Operation was verified by using laboratory signal analyzers to process the signals. The third section of this report summarizes the results of a Spectron Development Laboratory subcontract from ANL to investigate analytical techniques suitable for monitoring the concentration of gaseous alkali compounds in the hot gas stream from a fluidized-bed combustor. It was concluded from the study that the concept of using the Na/sub 2/SO/sub 4/ dew point to detect the onset of hot corrosion conditions is the most attractive of the techniques evaluated.

Johnson, I.; Podolski, W.F.; Myles, K.M.

1980-09-01

309

Reduction of particulate carryover from a pressurized fluidized bed  

NASA Technical Reports Server (NTRS)

A bench scale fluidized bed combustor was constructed with a conical shape so that the enlarged upper part of the combustor would also serve as a granular bed filter. The combustor was fed coal and limestone. Ninety-nine tests of about four hours each were conducted over a range of conditions. Coal-to-air ratio varied from 0.033 to 0.098 (all lean). Limestone-to-coal ratio varied from 0.06 to 0.36. Bed depth varied from 3.66 to 8.07 feet. Temperature varied from 1447 to 1905 F. Pressure varied from 40 to 82 psia. Heat transfer area had the range zero to 2.72 ft squared. Two cone angles were used. The average particulate carry over of 2.5 grains/SCF was appreciably less than cylindrical fluidized bed combustors. The carry over was correlated by multiple regression analysis to yield the dependence on bed depth and hence the collection efficiency, which was 20%. A comparison with a model indicated that the exhaust port may be below the transport disengaging height for most of the tests, indicating that further reduction in carry over and increase in collection efficiency could be affected by increasing the freeboard and height of the exhaust port above the bed.

Patch, R. W.

1979-01-01

310

Scaling of pressurized fluidized beds. First quarterly progress report, October 1, 1992--January 15, 1993  

SciTech Connect

Some preliminary work has been done to develop potential cold scale model designs to simulate the bed hydrodynamics of the American Electric Power Tidd pressurized bubbling fluidized bed combustor. The first design is based on the full set of scaling parameters presented in Equation (1), the second design was developed using the simplified set of scaling parameters given in Equation (2). The first design is roughly a 1:1 representation of a section of the core of the Tidd bed combustor. The additional flexibility provided by the simplified set of scaling parameters is particularly useful for developing experimental models of pressurized fluidized bed combustors where the full set of scaling relationships does not provide any reduction in the size of the models. Both the full and the simplified set of scaling relationships have been verified for applications to circulating fluidized bed combustors operating at atmospheric pressure. Currently there is a interest in fluidized bed combustors which operate at elevated pressures ({approximately}12 atm) for combined-cycle applications. One of the primary goals of this stud r is to verify both the till set and the simplified set of scaling relationships for applications to pressurized bubbling fluidized bed combustors.

Glicksman, L.; Farrell, P.

1993-09-01

311

Sorbent utilization prediction methodology: sulfur control in fluidized-bed combustors  

SciTech Connect

The United States Government has embarked on an ambitious program to develop and commercialize technologies to efficiently extract energy from coal in an environmentally acceptable manner. One of the more promising new technologies for steam and power generation is the fluidized-bed combustion of coal. In this process, coal is burned in a fluidized bed composed mainly of calcined limestone sorbent. The calcium oxide reacts chemically to capture the sulfur dioxide formed during the combustion and to maintain the stack gas sulfur emissions at acceptable levels. The spent sulfur sorbent, containing calcium sulfate, is a dry solid that can be disposed of along with coal ash or potentially used. Other major advantages of fluidized-bed combustion are the reduction in nitrogen oxide emissions because of the relatively low combustion temperatures, the capability of burning wide varieties of fuel, the high carbon combustion efficiencies, and the high heat-transfer coefficients. A key to the widespread commercialization of fluidized-bed technology is the ability to accurately predict the amount of sulfur that will be captured by a given sorbent. This handbook meets this need by providing a simple, yet reliable, user-oriented methodology (the ANL method) that allows performance of a sorbent to be predicted. The methodology is based on only three essential sorbent parameters, each of which can be readily obtained from standardized laboratory tests. These standard tests and the subsequent method of data reduction are described in detail.

Fee, D.C.; Wilson, W.I.; Shearer, J.A.; Smith, G.W.; Lenc, J.F.; Fan, L.S.; Myles, K.M.; Johnson, I.

1980-09-01

312

DESIGN AND CONSTRUCTION OF A FLUIDIZED-BED COMBUSTION SAMPLING AND ANALYTICAL TEST RIG  

EPA Science Inventory

The report describes the design, construction, and installation of a fluidized-bed coal combustion sampling and analytical test rig in the High Bay Area (Wing G) of EPA's Industrial Environmental Research Laboratory (IERL), Research Triangle Park, North Carolina. The rig, to be u...

313

Fluidized bed biofilm reactor for wastewater treatment  

Microsoft Academic Search

The fluidized bed biofilm reactor (FBBR) represents a recent innovation in biofilm processes. Immobilization of microorganisms on the small, fluidized particles of the medium results in a high reactor biomass holdup which enables the process to be operated at significantly higher liquid throughputs with the practical absence of biomass wash-out. The process intensification (i.e., a reduction in process size while

Wen K. Shieh; John D. Keenan

314

Improved Fluidized-Bed Gas Injector  

NASA Technical Reports Server (NTRS)

Gas-injection cone in fluidized-bed reactor for coating particles with silicon or carbon cooled and protected from abrasion by stream of gas flowing over surface of cone. Hot particles entering reaction zone are coated with silicon or carbon supplied by thermal decomposition of suitable gas injected into reaction zone.

Hogle, R. A.

1983-01-01

315

FBC: Gaining acceptance. [Fluidized Bed Combustion  

SciTech Connect

This article addresses the growing acceptance of fluidized bed combustion as a technology appropriate for use in dual-purpose power plants. The article reviews projects for cogeneration in California, a demonstration plant sponsored by the US Department of Energy in Ohio (this plant also incorporates combined cycle operation), and an electric power/greenhouse project in Pennsylvania.

Gawlicki, S.M.

1991-04-01

316

ADVANCED CONTROL STRATEGIES FOR FLUIDIZED BED DRYERS  

Microsoft Academic Search

Generating the best possible control strategy comprises a necessity for industrial processes, by virtue of product quality, cost reduction and design simplicity. Three different control approaches, namely an Input-Output linearizing, a fuzzy logic and a PID controller, are evaluated for the control of a fluidized bed dryer, a typical non-linear drying process of wide applicability. Based on several closed loop

C. I. Siettos; C. T. Kiranoudis; G. V. Bafas

1999-01-01

317

Fuzzy Control Of A Fluidized Bed Dryer  

Microsoft Academic Search

Fluidized bed dryers are utilised in almost every area of drying applications and therefore improved control strategies are always of great interest. The nonlinear character of the process, exhibited in the mathematical model and the open loop analysis, implies that a fuzzy logic controller is appropriate because, in contrast with conventional control schemes, fuzzy control inherently compensates for-process nonlinearities and

A. V. Taprantzis; C. I. Siettos; G. V. Bafas

1997-01-01

318

Fluidization quality analyzer for fluidized beds  

DOEpatents

A control loop and fluidization quality analyzer for a fluidized bed utilizes time varying pressure drop measurements. A fast-response pressure transducer measures the overall bed pressure drop, or over some segment of the bed, and the pressure drop signal is processed to produce an output voltage which changes with the degree of fluidization turbulence.

Daw, C. Stuart (Knoxville, TN); Hawk, James A. (Oak Ridge, TN)

1995-01-01

319

Pressurized Fluidized Bed Combustion of Sewage Sludge  

Microsoft Academic Search

A conceptual design of an energy recovering system from sewage sludge was proposed. This system consists of a pressurized fluidized bed combustor, a gas turbine, and a heat exchanger for preheating of combustion air. Thermal efficiency was estimated roughly as 10-25%. In order to know the combustion characteristics of the sewage sludge under the elevated pressure condition, combustion tests of

Yoshizo Suzuki; Tomoyuki Nojima; Akihiko Kakuta; Hiroshi Moritomi

2004-01-01

320

Fluidized bed electrowinning of copper. Final report  

SciTech Connect

The objectives of the study were to: design and construct a 10,000- amp fluidized bed electrowinning cell for the recovery of copper from acidic sulfate solutions; demonstrate the technical feasibility of continuous particle recirculation from the electrowinning cell with the ultimate goal of continuous particle removal; and measure cell efficiency as a function of operating conditions.

NONE

1997-07-01

321

In-bed circulating fluidized bed  

Microsoft Academic Search

Experience shows that fuel and bed material in a conventional vertically fluidized bed tends to mix within a maximum of a 6 to 10 square foot area. If the area is smaller, even better consistency is achieved. Thus, for each such increment of bed area, an additional feeder and ash extraction point are required. If not, the bed will not

Manicke

1984-01-01

322

Fluidized Bed Gasification of Biomass to Methane.  

National Technical Information Service (NTIS)

Biomass particles are pelletized in pelletizer. The pellets form a fluidized bed of biomass in hot steam gas fed into the bottom inlet of a reactor. Catalyst particles shower downwardly through the reactor and are collected in an engager before recycle. T...

S. A. Qader

1983-01-01

323

Metal Wastage in Fluidized-Bed Combustors.  

National Technical Information Service (NTIS)

Objectives of the research are (1) to develop guidelines for the design and operation of fluidized-bed combustion (FBC) units with minimum metal wastage rates and (2) to develop continuous erosion monitors for use in pilot plant and full-scale FBC units. ...

G. F. Berry W. F. Podolski K. J. Reimann R. W. Lyczkowski C. A. Youngdahl

1987-01-01

324

Controlling the Chaotic Hydrodynamics of Fluidized Beds.  

National Technical Information Service (NTIS)

The goal of this work was to develop a control method to manipulate and modify the hydrodynamics of gas-solid fluidized beds, especially to enhance mass transfer by reducing the bubble size for Geldart group B type particle systems. An increased mass tran...

R. J. De Korte

2000-01-01

325

SOLIDS TRANSPORT BETWEEN ADJACENT CAFB FLUIDIZED BEDS  

EPA Science Inventory

The report gives results of an experimental investigation of a pulsed, dense-phase pneumatic transport system for controlled circulation between adjacent fluidized beds. A model was developed to predict performance. The program provides technical support for EPA's program to demo...

326

Particle pressures in fluidized beds. Final report  

SciTech Connect

This project studies the particle pressure, which may be thought of as the force exerted by the particulate phase of a multiphase mixture, independently of that exerted by other phases. The project is divided into two parts, one concerning gas and the other liquid fluidized beds. Previous work on gas fluidized beds had suggested that the particle pressures are generated by bubbling action. Thus, for these gas fluidized bed studies, the particle pressure is measured around single bubbles generated in 2-D fluidized beds, using special probes developed especially for this purpose. Liquid beds are immune from bubbling and the particle pressures proved too small to measure directly. However, the major interest in particle pressures in liquid beds lies in their stabilizing effect that arises from the effective elasticity (the derivative of the particle pressure with respect to the void fraction), they impart to the bed. So rather than directly measure the particle pressure, the authors inferred the values of the elasticity from measurements of instability growth in liquid beds; the inference was made by first developing a generic stability model (one with all the normally modeled coefficients left undetermined) and then working backwards to determine the unknown coefficients, including the elasticity.

Campbell, C.S.; Rahman, K.; Jin, C.

1996-09-01

327

Particle Pressures in Fluidized Beds. Final report  

SciTech Connect

This project studies the particle pressure, which may be thought of as the force exerted by the particulate phase of a multiphase mixture, independently of that exerted by other phases. The project is divided into two parts, one concerning gas and the other liquid fluidized beds. Previous work on gas fluidized beds had suggested that the particle pressures are generated by bubbling action. Thus, for these gas fluidized bed studies, the particle pressure is measured around single bubbles generated in 2-D fluidized beds, using special probes developed especially for this purpose. Liquid beds are immune from bubbling and the particle pressures proved too small to measure directly. However, the major interest in particle pressures in liquid beds lies in their stabilizing effect that arises from the effective elasticity (the derivative of the particle pressure with respect to the void fraction): they impart to the bed. So rather than directly measure the particle pressure, we inferred the values of the elasticity from measurements of instability growth in liquid beds the inference was made by first developing a generic stability model (one with all the normally modeled coefficients left undetermined)and then working backwards to determine the unknown coefficients, including the elasticity.

Campbell, C.S.; Rahman, K.; Jin, C.

1996-09-01

328

Fluidized Bed Steam Reformer (FBSR) monolith formation  

Microsoft Academic Search

Fluidized Bed Steam Reforming (FBSR) is being considered as an alternative technology for the immobilization of a wide variety of aqueous high sodium containing radioactive wastes at various DOE facilities in the United States. The addition of clay, charcoal, and a catalyst as co-reactants converts aqueous Low Activity Wastes (LAW) to a granular or 'mineralized' waste form while converting organic

C. M. Jantzen

2007-01-01

329

Performance analysis of co-firing waste materials in an advanced pressurized fluidized-bed combustor  

SciTech Connect

The co-firing of waste materials with coal in utility scale power plants has emerged as an effective approach to produce energy and manage municipal wastes. Leading this approach is the atmospheric fluidized-bed combustor (AFBC). It has demonstrated its commercial acceptance in the utility market as a reliable source of power by burning a variety of waste and alternative fuels. The application of pressurized fluidized-bed combustor (PFBC) technology, although relatively new, can provide significant enhancements to the efficient production of electricity while maintaining the waste management benefits of AFBC. A study was undertaken to investigate the technical and economical feasibility of co-firing a PFBC with coal and municipal and industrial wastes. Focus was placed on the production of electricity and the efficient disposal of wastes for application in central power station and distributed locations. Issues concerning waste material preparation and feed, PFBC operation, plant emissions, and regulations are addressed. The results and conclusions developed are generally applicable to current and advanced PFBC design concepts. Wastes considered for co-firing include municipal solid waste (MSW), sewage sludge, and industrial de-inking sludge. Conceptual designs of two power plants rated at 250 MWe and 150 MWe were developed. Heat and material balances were completed for each plant along with environmental issues. With the PFBC`s operation at high temperature and pressure, efforts were centered on defining feeding systems capable of operating at these conditions. Air emissions and solid wastes were characterized to assess the environmental performance comparing them to state and Federal regulations. This paper describes the results of this investigation, presents conclusions on the key issues, and provides recommendations for further evaluation.

Bonk, D.L.; McDaniel, H.M. [USDOE Morgantown Energy Technology Center, WV (United States); DeLallo, M.R. Jr.; Zaharchuk, R. [Gilbert/Commonwealth, Inc., Reading, PA (United States)

1995-07-01

330

Characterizing and modeling combustion of mild-gasification chars in pressurized fluidized beds  

SciTech Connect

Oak Ridge National Laboratory (ORNL) is supported by the Morgantown Energy Technology Center (METC) of the Department of Energy (DOE) under FWP-FEAA310 to characterize the fuel properties of liquid and char coproducts from the mild gasification of coal, Because most of the energy content of coals subjected to mild gasification is retained in the byproduct char, efficient and cost-effective utilization of the char is essential in insuring that candidate gasification processes are commercially viable. One potential use for char of particular interest to DOE is pressurized fluidized bed combustion (PFBC). PFBC is of particular interest because it has the potential for 10 to 30 percent greater overall energy efficiency than atmospheric fluidized bed combustion (AFBC), While bench-scale tools and analytical procedures for characterizing fuels for AFBC have been recently demonstrated, no such tools have been reliably demonstrated for PFBC. This report summarizes the results of joint research collaboration between ORNL and B&W that has been directed at modifying the previously developed AFBC fuel characterization procedures to be applicable for mild-gasification chars and PFBC conditions. The specific objectives were to: (1) characterize the combustion reactivity of a selected set of candidate mild- gasification chars at PFB conditions; (2) compare the measured char characteristics with those of more conventional PFBC fuels; (3) modify an AFBC computer code previously developed by B&W and ORNL for the Electric Power Research Institute (EPRI) to predict PFBC performance; and (4) apply the modified code and measured char combustion characteristics to make performance predictions for the candidate chars relative to more conventional fuels.

Daw, C.S.

1995-10-01

331

Modeling carbonizing process in fluidized bed  

NASA Astrophysics Data System (ADS)

This paper presents possibility of using neural networks model for designing carbonizing process in fluidized bed. This process is very complicated and difficult as multi-parameters changes are non linear and car drive cross structure is non homogeneous. This fact and lack of mathematical algorithms describing this process makes modeling properties of drives elements by traditional numerical methods difficult or even impossible. In this case it is possible to try using artificial neural network. Using neural networks for modeling carbonizing in fluidized bed is caused by several nets' features: non linear character, ability to generalize the results of calculations for data out of training set, no need for mathematical algorithms describing influence changes input parameters on modeling materials properties. The neural network structure is designed and special prepared by choosing input and output parameters of process. The method of learning and testing neural network, the way of limiting nets structure and minimizing learning and testing error are discussed. Such prepared neural network model, after putting expected values of car cross driving properties in output layer, can give answers to a lot of questions about running carbonizing process in fluidized bed. The practical implications of the neural network models are possibility of using they to build control system capable of on-line controlling running process and supporting engineering decision in real time. The originality of this research is different conception to obtain foreseen materials properties after carbonizing in fluidized bed. The specially prepared neural networks model could be a help for engineering decisions and may be used in designing carbonizing process in fluidized bed as well as in controlling changes of this process.

Szota, M.; Jasinski, J.

2010-06-01

332

Effect of CaO on retention of S, Cl, Br, As, Mn, V, Cr, Ni, Cu, Zn, W and Pb in bottom ashes from fluidized-bed coal combustion power station.  

PubMed

This work was conducted to evaluate whether Ca-bearing additives used during coal combustion can also help with the retention of some other elements. This work was focused on the evaluation of bottom ashes collected during four full-scale combustion tests at an operating thermal fluidized-bed power station. Bottom ashes were preferred to fly ashes for the study to avoid interference from condensation processes usually occurring in the post-combustion zone. This work focused on the behaviors of S, Cl, Br, As, Mn, V, Cr, Ni, Cu, Zn, W, and Pb. Strong positive correlations with CaO content in bottom ashes were observed (for all four combustion tests) for S, As, Cl and Br (R=0.917-0.999). Strong inverse proportionality was calculated between the contents of Pb, Zn, Ni, Cr and Mn and CaO, so these elements showed association to materials other than Ca-bearing compounds (e.g., to aluminosilicates, organic matter, etc.). Somewhat unclear behaviors were observed for W, Cu, and V. Their correlation coefficients were evaluated as statistically "not significant", i.e., these elements were not thought to be significantly associated with CaO. It was also discovered that major enrichment of CaO in the finest bottom ash fractions could be advantageously used for simple separation of elements strongly associated with these fractions, mainly S and As, but also Cl or Br. Removal of 5% of the finest ash particles brings about a decrease in As concentration down to 77%-80% of its original bulk ash content, which can be conveniently used e.g., when high As content complicates further ash utilization. PMID:25079991

Barto?ová, Lucie; Klika, Zden?k

2014-07-01

333

Fluidized-bed combustion test of low-quality fuels. I. Anthracite refuse  

Microsoft Academic Search

A total of five types of anthracite refuse material with widely different characteristics have been successfully burned in the 18-inch diameter atmospheric pressure fluidized-bed combustor at the Morgantown Energy Research Center of the Energy Research and Development Administration. Combustion characteristics of these anthracite refuse materials as well as engineering data were investigated for a wide range of operation conditions. Values

J. S. Mei; R. L. Gall; J. S. Wilson

1977-01-01

334

Fluidized-Bed Combustion Development: Volume 1, Industrial Steam Generation: Final Report.  

National Technical Information Service (NTIS)

In 1986 Stearns Catalytic performed a study for the US Department of Energy to investigate methodology for improving the economics of atmospheric fluidized bed combustion (AFBC). This report is a result of Phase 1 of this program. The scope of this work i...

B. N. Gaglia R. L. Claussen

1986-01-01

335

Contribution of Dynamics and Erosion for Small Tube Arrays in Fluidized Beds.  

National Technical Information Service (NTIS)

The erosion issue in both atmospheric and pressurized fluidized bed combustors (AFBC's and PFBC's) has received increased attention in the last several years. The problem of erosion (more generally referred to as metal wastage) is so severe that in some c...

R. W. Lyczkowski J. X. Bouillard S. L. Chang S. Folga

1989-01-01

336

REGENERATION OF CALCIUM-BASED SO2 SORBENTS FOR FLUIDIZED-BED COMBUSTION: ENGINEERING EVALUATION  

EPA Science Inventory

The report gives results of an engineering evaluation of regeneration of calcium-based SO2 sorbents (limestone and dolomite) for application in both atmospheric and pressurized fluidized-bed combustion (FBC) processes. Economics of FBC power plants, operated with regeneration, ar...

337

Heat Transfer to Horizontal Tubes Immersed in a Fluidized-Bed Combustor.  

National Technical Information Service (NTIS)

Experiments were carried out to measure the heat transfer rates to water-cooled horizontal tubes immersed in an atmospheric fluidized-bed combustor burning North Dakota lignite. The effect of bed temperature (T/sub B/ = 587 to 1205K), particle size (anti ...

N. S. Grewal J. Menart D. R. Hajicek B. J. Zobeck

1986-01-01

338

Westinghouse fluidized bed coal gasification process for phosphoric acid fuel cell power plant. [Distributed Gas Cooled (DIGAS) fuel cell to be used in residential and commercial integrated energy systems  

Microsoft Academic Search

A system study performed on a 7.5 MW phosphoric acid fuel cell (PAFC) power plant, integrated with a Westinghouse fluidized bed gasifier is discussed. The direct capital cost and the cost of electricity are evaluated for this system. 4 refs.

S. V. Dighe; M. B. Blinn; J. J. Buggy; B. R. Krasicki; B. L. Pierce

1981-01-01

339

Bed material agglomeration during fluidized bed combustion  

SciTech Connect

The purpose of this project is to determine the physical and chemical reactions which led to the undesired agglomeration of bed material during fluidized bed combustion and to relate these reactions to specific causes. Survey of industrial-scale fluidized bed combustors is being conducted to determine the occurrence of bed agglomeration and the circumstances under which agglomeration took place. This task should be finished by the end of February. Samples of bed material, agglomerate material, and boiler deposits are being requested from boiler operators as part of the survey. Once received, these sample will be analyzed to determine chemical and mineralogic composition. The bulk chemical determination will be performed using x-ray fluorescence and inductively coupled plasma-optical emission (ICP). Mineralogy will be detected by x-ray diffraction (XRD). Chemical and mineral reactions will be determined by scanning electron microscopy, optical microscopy, and electron microprobe.

Brown, R.C.; Dawson, M.R.; Noble, S.

1993-02-01

340

Control of a Circulating Fluidized Bed  

SciTech Connect

Two methods for optimally controlling the operation of a circulating fluidized bed are being investigated, neural network control and Kalman filter control. The neural network controls the solids circulation rate by adjusting the flow of move air in the non-mechanical valve. Presented is the method of training the neural network from data generated by the circulating fluidized bed (CFB), the results of a sensitivity study indicating that adjusting the move air can control solids flow, and the results of controlling solids circulation rate. The Kalman filter approach uses a dynamic model and a measurement model of the standpipe section of the CFB. Presented are results showing that a Kalman filter can successfully find the standpipe bed height.

Shim, Hoowang; Rickards, Gretchen; Famouri, Parviz; Turton, Richard (WVU); Sams, W. Neal (EG& G); Koduro, Praveen; Patankar, Amol; Davari, Assad (WVUIT); Lawson, Larry; Boyle, Edward J. (DOE)

2001-11-06

341

Solar heated fluidized bed gasification system  

NASA Technical Reports Server (NTRS)

A solar-powered fluidized bed gasification system for gasifying carbonaceous material is presented. The system includes a solar gasifier which is heated by fluidizing gas and steam. Energy to heat the gas and steam is supplied by a high heat capacity refractory honeycomb which surrounds the fluid bed reactor zone. The high heat capacity refractory honeycomb is heated by solar energy focused on the honeycomb by solar concentrator through solar window. The fluid bed reaction zone is also heated directly and uniformly by thermal contact of the high heat capacity ceramic honeycomb with the walls of the fluidized bed reactor. Provisions are also made for recovering and recycling catalysts used in the gasification process. Back-up furnace is provided for start-up procedures and for supplying heat to the fluid bed reaction zone when adequate supplies of solar energy are not available.

Qader, S. A. (inventor)

1981-01-01

342

Proceedings - Sixth annual fluidized bed conference  

SciTech Connect

The proceedings contain 20 papers which deal with cogeneration facilities; refractory materials for liners of combustors (properties, failures, repair); and design, start-up, and operation of circulating fluidized bed combustors. Many of the systems describe use of anthracite waste as fuel, but petroleum coke, wood wastes, and municipal solid wastes are also mentioned as fuels in several of the systems. All papers have been processed separately for inclusion on the data base.

Not Available

1991-01-01

343

Biomass gasification in a circulating fluidized bed  

Microsoft Academic Search

This paper presents the results from biomass gasification tests in a pilot-scale (6.5-m tall × 0.1-m diameter) air-blown circulating fluidized bed gasifier, and compares them with model predictions. The operating temperature was maintained in the range 700–850°C, while the sawdust feed rate varied from 16 to 45kg\\/h. Temperature, air ratio, suspension density, fly ash re-injection and steam injection were found

X. T. Li; J. R. Grace; C. J. Lim; A. P. Watkinson; H. P. Chen; J. R. Kim

2004-01-01

344

Cluster Dynamics in a Circulating Fluidized Bed  

SciTech Connect

A common hydrodynamic feature in industrial scale circulating fluidized beds is the presence of clusters. The continuous formation and destruction of clusters strongly influences particle hold-up, pressure drop, heat transfer at the wall, and mixing. In this paper fiber optic data is analyzed using discrete wavelet analysis to characterize the dynamic behavior of clusters. Five radial positions at three different axial locations under five different operating were analyzed using discrete wavelets. Results are summarized with respect to cluster size and frequency.

Guenther, C.P.; Breault, R.W.

2006-11-01

345

Transitional behavior in gas-fluidized beds  

NASA Astrophysics Data System (ADS)

Examined at the macro-scale, fluidized beds may appear to behave like a solid, a liquid or a gas, depending on the magnitude of the applied superficial gas velocity. Using DEM simulations, the paper examines the different types of behavior as the gas velocity is increased to cover the complete range from fixed bed to homogeneous expansion, bubbling, turbulent and fast fluidization. The paper highlights the transitions between the various regimes.

Thornton, Colin; Yang, Fang; Seville, Jonathan

2013-06-01

346

Particle pressures in fluidized beds. Annual report  

SciTech Connect

Campbell and Wang (1991) showed that the particle pressures in gas-fluidized beds were largely generated by the passage of bubbles. In particular, they showed that the average particle pressure exerted on the side walls scaled with the average size of the bubble. This immediately brings to mind two questions: (1) what is it about bubbles that leads to particle pressure generation and (2) would there be measurable particle pressures in liquid-fluidized beds which, while unstable, do not bubble? This project is largely aimed at answering these two questions. To attack the first problem, the authors have built a two-dimensional gas-fluidized bed into which bubbles may be injected and the distribution of particle-pressure measured. For the latter, other experiments are being performed in liquid fluidized beds. However, it soon became apparent that the particle pressures generated in the liquid beds are extremely small. This has pointed that phase of the research in two directions. The first is the design and construction of a third, and more sensitive, from of the particle pressure transducer. The second approach arose from reflection on what ultimately was the utility of the current research. This led to the development of a generic stability model, in which all modeled terms are left unspecified. From analyzing this model, they have developed an experimental plan that, by measuring the characteristics of voidage disturbances and comparing with the theory, will allow them to back out appropriate values for the modeled terms. The results will not only yield insight into the particle pressure, but also of the fluid drag. The latter results may be used to evaluate common models for these terms.

Campbell, C.S.; Rahman, K.; Hu, X.; Jin, C.

1994-03-01

347

Fluidized-bed biological nitrogen removal  

SciTech Connect

This article describes a compact process for nitrogen removal developed in Japan. It does not require the large amounts of land of current denitrification processes. The process uses a three-phase fluidized bed of granular anthracite to which the nitrifying bacteria adhere and are fluidized by the activated sludge in the reactor. The process was developed in response to the need for nitrogen and phosphorus removal from waste water to prevent the eutrophication of Tokyo Bay, Japan.

Hosaka, Yukihisa; Minami, Takeshi; Nasuno, Sai (Bureau of Sewage, Tokyo (Japan))

1991-08-01

348

Wavy instability in liquid-fluidized beds  

SciTech Connect

Experiments on the primary wavy instability in a liquid-fluidized bed are designed to test the two-phase flow governing equations. The wave is shown to saturate along the bed. The saturated wave can be well described as a cnoidal wave. The solid-phase viscosity and pressure which are unknown in the two-phase model are deduced from the shape of the saturated wave. The validity of the two-phase Newtonian model is then questioned.

Nicolas, M.; Guazzelli, E. [ESPCI, Paris (France). Lab. de Physique et Mecanique des Milieux Heterogenes] [ESPCI, Paris (France). Lab. de Physique et Mecanique des Milieux Heterogenes; Hinch, J. [Univ. of Cambridge (United Kingdom). Dept. of Applied Mathematics and Theoretical Physics] [Univ. of Cambridge (United Kingdom). Dept. of Applied Mathematics and Theoretical Physics

1999-03-01

349

Use of glow discharge in fluidized beds  

NASA Technical Reports Server (NTRS)

Static charges and agglomerization of particles in a fluidized bed systems are minimized by maintaining in at least part of the bed a radio frequency glow discharge. This approach is eminently suitable for processes in which the conventional charge removing agents, i.e., moisture or conductive particle coatings, cannot be used. The technique is applied here to the disproportionation of calcium peroxide diperoxyhydrate to yield calcium superoxide, an exceptionally water and heat sensitive reaction.

Wydeven, T.; Wood, P. C.; Ballou, E. V.; Spitze, L. A. (inventor)

1981-01-01

350

Pressurized Fluidized Bed Combustion of Sewage Sludge  

NASA Astrophysics Data System (ADS)

A conceptual design of an energy recovering system from sewage sludge was proposed. This system consists of a pressurized fluidized bed combustor, a gas turbine, and a heat exchanger for preheating of combustion air. Thermal efficiency was estimated roughly as 10-25%. In order to know the combustion characteristics of the sewage sludge under the elevated pressure condition, combustion tests of the dry and wet sewage sludge were carried out by using laboratory scale pressurized fluidized bed combustors. Combustibility of the sewage sludge was good enough and almost complete combustion was achieved in the combustion of the actual wet sludge. CO emission and NOx emission were marvelously low especially during the combustion of wet sewage sludge regardless of high volatile and nitrogen content of the sewage sludge. However, nitrous oxide (N2O) emission was very high. Hence, almost all nitrogen oxides were emitted as the form of N2O. From these combustion tests, we judged combustion of the sewage sludge with the pressurized fluidized bed combustor is suitable, and the conceptual design of the power generation system is available.

Suzuki, Yoshizo; Nojima, Tomoyuki; Kakuta, Akihiko; Moritomi, Hiroshi

351

Hydrodynamic aspects of a circulating fluidized bed with internals  

SciTech Connect

An attempt is made to examine the influence of internals (baffles) in the riser of the circulating fluidized bed. Experiments are conducted in a circulating fluidized bed, having perforated plates with different free areas. It is noticed from the present work that a circulating fluidized bed having 45% free area gives uniform solids concentration and pressure drop along the length of the riser. In addition to the uniformity, the circulating fluidized bed with internals gives higher pressure drop (solids concentration) compared to a conventional circulating fluidized bed. For internals having 67.6% free area the pressure drop is higher at the lower portion of the riser compared to the upper portion, similar to a conventional circulating fluidized bed. For 30% free area plates the solids concentration varies axially within the stage and remains uniform from stage to stage.

Balasubramanian, N. [Indian Inst. of Tech., Madras (India). Dept. of Chemical Engineering] [Indian Inst. of Tech., Madras (India). Dept. of Chemical Engineering; Srinivasakannan, C. [Central Leather Research Inst., Madras (India). Chemical Engineering Div.] [Central Leather Research Inst., Madras (India). Chemical Engineering Div.

1998-06-01

352

Co-Combustion of Sewage Sludge with Wood\\/Coal in a Circulating Fluidized Bed Boiler A Study of Gaseous Emissions  

Microsoft Academic Search

Reduction of emissions of NO and N2O from co-combustion of wet or dried sewage sludge with coal or wood is investigated. This is motivated by the high nitrogen content in sewage sludge that may give rise to high emissions. An advanced air-staging method for combustion in circulating fluidised bed is applied. It is shown that with fluidised bed combustion the

L.-E. Åmand; B. Leckner

353

The modeling of the combustion of high-ash coal–char particles suitable for pressurised fluidized bed combustion: shrinking reacted core model  

Microsoft Academic Search

An investigation was undertaken involving the combustion of high-ash coal\\/char particles under conditions suitable for pressurised fluidised bed combustion, in order to evaluate an overall combustion model. The use of very poor quality feedstocks (greater than 40% ash, low calorific value and high sulphur content) in conventional pulverised fuel combustors (PFC) could be technically difficult and un-economical, and has the

Raymond Everson; Hein Neomagus; Rufaro Kaitano

2005-01-01

354

Experimental study and modelling of char combustion under fluidized bed conditions  

NASA Astrophysics Data System (ADS)

The combustion behavior of chars from two Chinese coals has been investigated in a laboratory scale bubbling fluidized bed system in Siegen University, Germany. Experimental equipment and method are introduced. The ‘shrinking-core’ model and the ‘shrinking-particle’ model were employed to evaluate the kinetic parameters. The results indicated that the char conversion process of these two coals can be well described by the two models.

Zhang, Yongzhe; Xu, Xiangdong; Wirsum, Manfred C.; Hamel, Stefan; Fett, Franz N.

1998-12-01

355

Bed material agglomeration during fluidized bed combustion. Final report  

SciTech Connect

The purpose of this project is to determine the physical and chemical reactions which lead to the undesired agglomeration of bed material during fluidized bed combustion of coal and to relate these reactions to specific causes. A survey of agglomeration and deposit formation in industrial fluidized bed combustors (FBCs) indicate that at least five boilers were experiencing some form of bed material agglomeration. Deposit formation was reported at nine sites with deposits most commonly at coal feed locations and in cyclones. Other deposit locations included side walls and return loops. Three general types of mineralogic reactions were observed to occur in the agglomerates and deposits. Although alkalies may play a role with some {open_quotes}high alkali{close_quotes} lignites, we found agglomeration was initiated due to fluxing reactions between iron (II) from pyrites and aluminosilicates from clays. This is indicated by the high amounts of iron, silica, and alumina in the agglomerates and the mineralogy of the agglomerates. Agglomeration likely originated in the dense phase of the FBC bed within the volatile plume which forms when coal is introduced to the boiler. Secondary mineral reactions appear to occur after the agglomerates have formed and tend to strengthen the agglomerates. When calcium is present in high amounts, most of the minerals in the resulting deposits are in the melilite group (gehlenite, melilite, and akermanite) and pyroxene group (diopside and augite). During these solid-phase reactions, the temperature of formation of the melilite minerals can be lowered by a reduction of the partial pressure of CO{sub 2} (Diopside + Calcite {r_arrow}Akermanite).

Brown, R.C.; Dawson, M.R.; Smeenk, J.L.

1996-01-01

356

The Nucla Circulating Fluidized-Bed Demonstration Project: A U.S. DOE post-project assessment  

SciTech Connect

This report is a post-project assessment of the Nucla Circulating Fluidized-Bed (CFB) Demonstration Project, the second project to be completed in the DOE Clean Coal Technology Program. Nucla was the first successful utility repowering project in the US, increasing the capacity of the original power station from 36 MW(e) to 110 MW(e) and extending its life by 30 years. In the CFB boiler, combustion and desulfurization both take place in the fluidized bed. Calcium in the sorbent captures sulfur dioxide and the relatively low combustion temperatures limit NOx formation. Hot cyclones separate the larger particles from the gas and recirculates them to the lower zones of the combustion chambers. This continuous circulation of coal char and sorbent particles is the novel feature of CFB technology. This demonstration project significantly advanced the environmental, operational, and economic potential of atmospheric CFB technology, precipitating a large number of orders for atmospheric CFB equipment. By 1994, more than 200 atmospheric CFB boilers have been constructed worldwide. Although at least six CFB units have been operated, the Nucla project`s CFB database continues to be an important and unique resource for the design of yet larger atmospheric CFB systems. The post-project assessment report is an independent DOE appraisal of the success a completed project had in achieving its objectives and aiding in the commercialization of the demonstrated technology. The report also provides an assessment of the expected technical, environmental, and economic performance of the commercial version of the technology as well as an analysis of the commercial market.

NONE

1995-06-01

357

NO\\/sub x\\/ emission control for the design and operation of fluidized-bed combustion systems. Final report  

Microsoft Academic Search

This report deals with the reduction of NO\\/sub x\\/ with char in a hot fluid bed. The fluidized bed combustor with its high heat transfer rates is one possibility for improving the potential for coal use. As in all coal-fired systems, control of nitric oxide emissions is a major environmental concern because of its harm to vegetation and human health

Bailie

1984-01-01

358

Modelling coal gasification with a hybrid neural network  

Microsoft Academic Search

Gasification of two coals was carried out in a batch feed fluidized bed reactor at atmospheric pressure using steam as fluidizing medium. A model of coal gasification was developed, incorporating a first-principles model with a neural network parameter estimator. The hybrid neural network was trained with experimental data for the two coals and gave good performance in process modelling. A

Bing Guo; Youting Shen; Dingkai Li; Fu Zhao

1997-01-01

359

Development of second-generation pressurized fluidized bed combustion process  

SciTech Connect

Under the sponsorship of the United States Department of Energy, Foster Wheeler Development Corporation, and its team members, Westinghouse, Gilbert/Commonwealth, and the Institute of Gas Technology are developing second-generation pressurized fluidized bed combustion technology capable of achieving net plant efficiency in excess of 45 percent based on the higher heating value of the coal. A three-phase program entails design and costing of a 500 MWe power plant and identification of developments needed to commercialize this technology (Phase 1), testing of individual components (Phase 2), and finally testing these components in an integrated mode (Phase 3). This paper briefly describes the results of the first two phases as well as the progress on the third phase. Since other projects which use the same technology are in construction or in negotiation stages -- namely, the Power System Development Facility and the Four Rivers Energy Modernization Projects -- brief descriptions of these are also included.

Wolowodiuk, W.; Robertson, A. [Foster Wheeler Development Corp., Livingston, NJ (United States); Bonk, D. [USDOE Morgantown Energy Technology Center, WV (United States)

1994-10-01

360

Analysis and modeling of in-bed tube erosion in a gaseous fluidized bed  

SciTech Connect

Erosion by impingement of bed materials (ash, coal, and sorbents) on in-bed components has caused serious problems to many fluidized bed combustion (FBC) systems in the past few decades. The author conducted an experimental study, supplemented with theoretical analysis, in which erosion-prone tubes were placed inside a fluidized bed of uniformly sized glass beads to accelerate the mass removal process of the in-bed tubes. Effects of tube-to-distributor clearance, superficial velocity, tube orientation and location, tube circumferential angle, tube bundle height and configuration, and particle size on tube erosion were investigated, identified and discussed. It was found that tube erosion occurred only at a threshold fluidizing velocity (26 cm/s), close to the minimum fluidizing velocity (19 cm/s), and increased almost linearly with increasing superficial velocity. The average specific erosion rate of a tube bundle was about one order of magnitude lower than that of a single tube under the same test conditions. The erosion of a staggered bundle was found larger by 45% than that of an in-line bundle having identical tube pitches. Mathematical modeling of gas-particle flow in the fluidized bed with an in-bed tube was pursued to explore the particle motion and its effect on tube erosion. An erosion model was developed to describe and analyze the phenomenon of in-bed tube erosion. A series of improved electrostatic impact probes, based on the triboelectric effect of moving particles, were developed and used as a primary standard for measuring the particle-surface collision frequency in the fluidized bed. Design guidelines were proposed for fluidized bed systems for planning counter measures against in-bed tube erosion.

Lee, S. W.

1989-01-01

361

Spatiotemporal dynamics of a shallow fluidized bed.  

SciTech Connect

An experimental and theoretical study of the dynamics of an air-fluidized thin granular layer is presented. Near the threshold of instability, the system exhibits critical behavior with remarkably long transient dynamics. Above the threshold of fluidization the system undergoes a Hopf bifurcation as the layer starts to oscillate at a certain frequency due to a feedback between the layer dilation and the airflow rate. Based on our experimental data, we formulate a the simple dynamical model which describes the transition in a shallow fluidized bed.

Aranson, I. S.; Tsimring, L. S.; Clark, D. K.

2000-12-05

362

Fluidized-Bed Cleaning of Silicon Particles  

NASA Technical Reports Server (NTRS)

Fluidized-bed chemical cleaning process developed to remove metallic impurities from small silicon particles. Particles (250 micrometer in size) utilized as seed material in silane pyrolysis process for production of 1-mm-size silicon. Product silicon (1 mm in size) used as raw material for fabrication of solar cells and other semiconductor devices. Principal cleaning step is wash in mixture of hydrochloric and nitric acids, leaching out metals and carrying them away as soluble chlorides. Particles fluidized by cleaning solution to assure good mixing and uniform wetting.

Rohatgi, Naresh K.; Hsu, George C.

1987-01-01

363

Transients in a circulating fluidized bed boiler  

NASA Astrophysics Data System (ADS)

Transients in a circulating fluidized bed boiler firing biomass are considered. An attempt is made to describe transients with the use of concepts applied in the automatic control theory. The parameters calculated from an analysis of unsteady heat balance equations are compared with the experimental data obtained in the 12-MW boiler of the Chalmers University of Technology. It is demonstrated that these equations describe the transient modes of operation with good accuracy. Dependences for calculating the time constants of unsteady processes are obtained.

Baskakov, A. P.; Munts, V. A.; Pavlyuk, E. Yu.

2013-11-01

364

Combined fluidized-bed retort and combustor  

SciTech Connect

The present invention is directed to a combined fluidized bed retorting and combustion system particularly useful for extracting energy values from oil shale. The oil-shale retort and combustor are disposed side-by-side and in registry with one another through passageways in a partition therebetween. The passageways in the partition are submerged below the top of the respective fluid beds to preclude admixing or the product gases from the two chambers. The solid oil shale or bed material is transported through the chambers by inclining or slanting the fluidizing medium distributor so that the solid bed material, when fluidized, moves in the direction of the downward slope of the distributor.

Shang, J.Y.; Notestein, J.E.; Mei, J.S.; Zeng, L.W.

1982-04-14

365

Combined fluidized bed retort and combustor  

SciTech Connect

The present invention is directed to a combined fluidized bed retorting and combustion system particularly useful for extracting energy values from oil shale. The oil-shale retort and combustor are disposed side-by-side and in registry with one another through passageways in a partition therebetween. The passageways in the partition are submerged below the top of the respective fluid beds to preclude admixing or the product gases from the two chambers. The solid oil shale or bed material is transported through the chambers by inclining or slanting the fluidizing medium distributor so that the solid bed material, when fluidized, moves in the direction of the downward slope of the distributor.

Shana, J.Yu.; Mei, J.S.; Notestein, J.E.; Zeng, L.W.

1984-05-08

366

Gas fluidized-bed stirred media mill  

SciTech Connect

A gas fluidized-bed stirred media mill is provided for comminuting solid particles. The mill includes a housing enclosing a porous fluidizing gas diffuser plate, a baffled rotor and stator, a hollow drive shaft with lateral vents, and baffled gas exhaust exit ports. In operation, fluidizing gas is forced through the mill, fluidizing the raw material and milling media. The rotating rotor, stator and milling media comminute the raw material to be ground. Small entrained particles may be carried from the mill by the gas through the exit ports when the particles reach a very fine size. 2 figs.

Sadler, L.Y. III

1997-10-28

367

Gas fluidized-bed stirred media mill  

DOEpatents

A gas fluidized-bed stirred media mill is provided for comminuting solid ticles. The mill includes a housing enclosing a porous fluidizing gas diffuser plate, a baffled rotor and stator, a hollow drive shaft with lateral vents, and baffled gas exhaust exit ports. In operation, fluidizing gas is forced through the mill, fluidizing the raw material and milling media. The rotating rotor, stator and milling media comminute the raw material to be ground. Small entrained particles may be carried from the mill by the gas through the exit ports when the particles reach a very fine size.

Sadler, III, Leon Y. (Tuscaloosa, AL)

1997-01-01

368

Combined fluidized bed retort and combustor  

DOEpatents

The present invention is directed to a combined fluidized bed retorting and combustion system particularly useful for extracting energy values from oil shale. The oil-shale retort and combustor are disposed side-by-side and in registry with one another through passageways in a partition therebetween. The passageways in the partition are submerged below the top of the respective fluid beds to preclude admixing or the product gases from the two chambers. The solid oil shale or bed material is transported through the chambers by inclining or slanting the fluidizing medium distributor so that the solid bed material, when fluidized, moves in the direction of the downward slope of the distributor.

Shang, Jer-Yu (Fairfax, VA); Notestein, John E. (Morgantown, WV); Mei, Joseph S. (Morgantown, WV); Zeng, Li-Wen (Morgantown, WV)

1984-01-01

369

Packed fluidized bed blanket for fusion reactor  

DOEpatents

A packed fluidized bed blanket for a fusion reactor providing for efficient radiation absorption for energy recovery, efficient neutron absorption for nuclear transformations, ease of blanket removal, processing and replacement, and on-line fueling/refueling. The blanket of the reactor contains a bed of stationary particles during reactor operation, cooled by a radial flow of coolant. During fueling/refueling, an axial flow is introduced into the bed in stages at various axial locations to fluidize the bed. When desired, the fluidization flow can be used to remove particles from the blanket.

Chi, John W. H. (Mt. Lebanon, PA)

1984-01-01

370

Pressure Fluctuations as a Diagnostic Tool for Fluidized Beds  

SciTech Connect

The purpose of this project is to investigate the origin of pressure fluctuations in fluidized bed systems. The study will asses the potential for using pressure fluctuations as an indicator of fluidized bed hydrodynamics in both laboratory scale cold-models and industrial scale boilers.

Joel R. Schroeder; Robert C. Brown

1998-04-23

371

Kinetic behavior of solid particles in fluidized beds  

SciTech Connect

The overall objectives of this project are to develop experimental techniques for measuring the forces of fluidized particles, and to predict the solid-gas performance in fluidized beds by using data analysis system, and by elucidating the intrinsic mechanism of erosion and attrition phenomena in fluidized beds. The reduction of erosion and attrition rates is one of the critical engineering problems for the design and operation of fluidized bed combustors. Specifically, the objectives are to: (1) develop the experimental techniques to measure the forces of solid particles prevailing in fluidized beds: (2) measure and characterize the forces of solid particles in various types of fluidized beds with various configurations (conventional and spouted fluidized beds) and with different scales (10, 20, and 30cm) under various fluidization conditions (particle size, bed aspect ratio and gas velocity); (3) find and verify the mechanism of erosion rates of in-bed tubes and attrition rates of fluidized particles by forces of solid particles in fluidized beds. We developed three different kinds of measurement methods, i.e., fracture sensitive sensor, piezoelectric sensor and gas pressure fluctuation method. By using these methods the exact forces of solid particles, including the transient corporate in fluidized beds, were systematically measured. Simultaneously, the erosion rates of in-bed tubes and attrition rates of fluidized particles were measured. 69 figs., 9 tabs.

Kono, H.O.

1990-06-01

372

Improved Fluidized-Bed Reactor With Horizontal Staging  

NASA Technical Reports Server (NTRS)

Design of fluidized-bed reactor containing multiple, horizontally arrayed stages offers advantages over present multistage fluidized bed reactors with horizontal, vertical, or slanted stacking. In new reactor, solids proceed from one stage to next by flow over weir. Design promotes conservation of energy and optimization of flows and residence times.

Sullivan, Thomas A.

1992-01-01

373

Bubble size reduction in a fluidized bed by electric fields  

Microsoft Academic Search

The reduction of the size of bubbles can improve both selectivity and conversion in gas-solid fluidized beds. Results are reported of the reduction of bubble size by the application of electric fields to uncharged, polarizable particles in fluidized beds. It is shown how average bubble diameters can be drastically reduced, with little change of the bed expansion. A literature review

Flip Kleijn van Willigen; J. Van Turnhout; J. R. Van Ommen; Cor van den Bleek

2003-01-01

374

Pressure Fluctuations as a Diagnostic Tool for Fluidized Beds  

SciTech Connect

The purpose of this project was to investigate the origin of pressure fluctuations in fluidized bed systems. The study assessed the potential for using pressure fluctuations as an indicator of fluidized bed hydrodynamics in both laboratory scale cold-models and industrial scale boilers. Both bubbling fluidized beds and circulating fluidized beds were evaluated. Testing including both cold-flow models and laboratory and industrial-scale combustors operating at elevated temperatures. The study yielded several conclusions on the relationship of pressure fluctuations and hydrodynamic behavior in fluidized beds. The study revealed the importance of collecting sufficiently long data sets to capture low frequency (on the order of 1 Hz) pressure phenomena in fluidized beds. Past research has tended toward truncated data sets collected with high frequency response transducers, which miss much of the spectral structure of fluidized bed hydrodynamics. As a result, many previous studies have drawn conclusions concerning hydrodynamic similitude between model and prototype fluidized beds that is insupportable from the low resolution data presented.

Ethan Bure; Joel R. Schroeder; Ramon De La Cruz; Robert C. Brown

1998-05-01

375

Evaluation of the Fluidized Bed Combustion Process. Volume III. Appendices.  

National Technical Information Service (NTIS)

The results of the evaluation of fluidized bed combustion for steam/power generation are presented in the three-volume report. The research concerns two fluidized bed fuel processing systems which should meet both market requirements and air pollution aba...

D. H. Archer D. L. Keairns J. R. Hamm

1971-01-01

376

DEM–CFD modeling of a fluidized bed spray granulator  

Microsoft Academic Search

Coupled DEM–CFD simulations have been performed to study the fluid and particle dynamics in a fluidized bed spray granulator on the scale of individual particles. The aim of this study is to develop a model of a fluidized bed granulator by combining the gas and particle dynamics with a simple model of particle wetting. Based on material tests, the collision

L. Fries; S. Antonyuk; S. Heinrich; S. Palzer

2011-01-01

377

Local conductivity of a fluidized bed consisting of conducting particles  

NASA Astrophysics Data System (ADS)

The electrical conductivity distribution over the height of the fluidized bed (coke, fraction 0.25-0.4 mm) has been investigated experimentally under various liquefaction conditions. Analysis of the conductivity fluctuations in the fluidized bed has been performed and its mechanism, taking into account the interaction between the bed phases, is proposed.

Malinovskii, A. I.; Rabinovich, O. S.; Borodulya, V. A.; Greben'kov, A. Zh.; Sidorovich, A. M.

2012-03-01

378

Heat transfer coefficients in three phase fluidized beds  

Microsoft Academic Search

In order to obtain a semitheoretical correlation for the heat transfer coefficients in three phase fluidized beds, Deckwer's semitheoretical correlation for the heat transfer coefficients in the bubble column, which was derived from Higbie's surface renewal theory of interphase mass transfer with the concept of isotropic turbulence, has been extended to three phase fluidized beds with the modification of the

I. S. Suh; G. T. Jin; S. D. Kim

1985-01-01

379

Recirculating fluidized bed combustion system for a steam generator  

SciTech Connect

The invention comprises a steam generator fluidized bed which recirculates through a major portion of the normal gas to fluid heat transfer circuits. Solid bed material is separated, collected and recirculated. Bed temperatures are limited by regulation of density of bed inert material to inhibit the radiant aspects of combustion. Gas recirculation is used to supplement air flow to achieve higher than entrainment bed gas velocity in the fuel ignition and reaction zone. Fuel ignition and reaction are controlled by limiting the amount of atmospheric air flow to the circulating fuel rich bed mixture to regulate extent of propagation of the ignition and reaction zone into the initial portion of the circulating bed loop, starting from the point of highest gas pressure.

Strohmeyer, C. Jr.

1984-04-17

380

Fermentation in a fluidized-bed reactor  

SciTech Connect

A laboratory-scale fluidized-bed bioreactor system for the production of ethanol from a glucose solution using flocculating Zymomonas mobilis was studied. Although the results are preliminary, 2.5- to 3.8-cm-diameter systems were operated for more than 300 h using fluidized floc particles that are 1-2 mm in diameter. The ethanol production rate in the lower portion of the fluidized bed operating at 30/sup 0/C routinely exceeded 200 g/L x h and under some conditions was as high as 400 g/ L x h with a reactor residence time of a few minutes. This far surpasses the results obtained with a batch, stirred-tank reactor using yeast. Ethanol productivity based on the total reactor volume approached 100 g/L x h, and glucose conversion exceeded 95%. With continued research, even higher production rates will be possible as conditions are optimized and scale-up to larger systems will allow the establishment of technical feasibility.

Scott, C.D.

1983-06-01

381

Fluidized bed gasification of select granular biomaterials.  

PubMed

Biomaterials can be converted into solid, liquid and gaseous fuels through thermochemical or biochemical conversion processes. Thermochemical conversion of granular biomaterials is difficult because of its physical nature and one of the suitable processes is fluidized bed gasification. In this study, coir pith, rice husk and saw dust were selected and synthetic gas was generated using a fluidized bed gasifier. Gas compositions of product gas were analyzed and the percentage of carbon monoxide and carbon dioxide was in the range of 8.24-19.55 and 10.21-17.14, respectively. The effect of equivalence ratio (0.3, 0.4 and 0.5) and reaction time (at 10 min interval) on gas constituents was studied. The gas yield for coir pith, rice husk and sawdust were found to be in the range of 1.98-3.24, 1.79-2.81 and 2.18-3.70 Nm3 kg(-1), respectively. Models were developed to study the influence of biomaterial properties and operating conditions on molar concentration of gas constituents and energy output. PMID:20817445

Subramanian, P; Sampathrajan, A; Venkatachalam, P

2011-01-01

382

The use of FBC wastes in the reclamation of coal slurry solids  

Microsoft Academic Search

Fluidized bed combustion (FBC) is a relatively new technology that is used commercially for the combustion of coal. In Illinois, this technology is valuable because it allows the combustion of Illinois high sulfur coal without pollution of the atmosphere with vast quantities of sulfur oxides. In FBC, coal is mixed with limestone or dolomite either before injection into the combustion

Dreher

1991-01-01

383

Environmental assesment of solid residues from fluidized-bed fuel processing. Final report November 1975December 1977  

Microsoft Academic Search

The report gives results of a 2-year study of the environmental assessment of solid residues generated by fluidized-bed combustion (FBC) of coal and gasification of oil. Included are a literature search, chemical and physical residue characterization, laboratory leaching studies, and testing of residues in various materials and agricultural applications. The literature search reviewed current FBC technology, identified products in which

R. Stone; R. L. Kahle

1978-01-01

384

Environmental assessment of solid residues from fluidized-bed fuel processing. Initial report November 1975December 1976  

Microsoft Academic Search

The report gives results of the first 15 months of an environmental assessment of solid residues generated by fluidized-bed combustion (FBC) of coal and gasification of oil. Included are a literature search, chemical and physical residue characterization, laboratory leaching studies, and testing of residues in various materials and agricultural applications. The literature search reviewed current FBC technology, identified products in

R. Stone; R. Kahle

1977-01-01

385

Analysis of Combined Potassium Topping, Steam Bottom Cycles Using Fluidized-Bed Combustion of Consol Char. Final Report.  

National Technical Information Service (NTIS)

The Consol process for making synthetic crude oil from coal produces a char that is an undesirable fuel but can be burned for power generation in a fluidized bed. Instead of using steam as the working fluid, potassium was chosen for analysis, since a high...

A. Himmelblau

1977-01-01

386

ENVIRONMENTAL ASSESSMENT: SOURCE TEST AND EVALUATION REPORT--EXXON MINIPLANT PRESSURIZED FLUIDIZED-BED COMBUSTOR WITH SORBENT REGENERATION  

EPA Science Inventory

The report gives results of a comprehensive emission sampling and analysis of the EPA-sponsored, Exxon Miniplant, pressurized, coal-fired, fluidized-bed combustor (PFBC) and sorbent regeneration system. Air pollutant emissions of seven trace elements exceeded emissions goals in t...

387

EFFECT OF EMISSION CONTROL REQUIREMENTS ON FLUIDIZED-BED BOILERS FOR INDUSTRIAL APPLICATIONS: PRELIMINARY TECHNICAL/ECONOMIC ASSESSMENT  

EPA Science Inventory

The report gives results of an assessment of coal-fired industrial fluidized-bed boilers (FBBs) to estimate the impact, on boiler cost and performance, of alternative control levels for SOx, NOx, and particulate emissions. Base industrial FBB conceptual designs are presented, and...

388

Biological and oxidative treatment of cotton textile dye-bath effluents by fixed and fluidized bed reactors  

Microsoft Academic Search

A treatability study for highly polluted and recalcitrant azo reactive dye-baths from cotton textile dyeing processes was conducted by using fixed and up-flow fluidized bed type reactors packed with brown coal. Ozone oxidation was carried out to assess the combination of biological and chemical oxidation. COD removal efficiencies ranged from 70% to 93%, and up to 99% color removal was

A. Baban; A. Yediler; G. Avaz; S. S. Hostede

2010-01-01

389

Alkali-Metal-Vapor Removal from Pressurized Fluidized-Bed-Combustor Flue Gas. Annual Report, October 1981-September 1982.  

National Technical Information Service (NTIS)

This work supports the program to develop sorbents for the cleanup of gases from pressurized fluidized-bed coal combustion (PFBC) so that the cleaned hot gases can be used to power downstream gas turbines without causing corrosion. A simulated PFBC flue g...

S. H. D. Lee K. M. Myles A. A. Jonke

1983-01-01

390

The use of FBC wastes in the reclamation of coal slurry solids. Technical report, September 1November 30, 1991  

Microsoft Academic Search

Fluidized bed combustion (FBC) is a relatively new technology that is used commercially for the combustion of coal. In Illinois, this technology is valuable because it allows the combustion of Illinois high sulfur coal without pollution of the atmosphere with vast quantities of sulfur oxides. In FBC, coal is mixed with limestone or dolomite either before injection into the combustion

Dreher

1991-01-01

391

The use of FBC wastes in the reclamation of coal slurry solids. Technical report, March 1, 1992May 31, 1992  

Microsoft Academic Search

Fluidized bed combustion (FBC) is a relatively new technology that is used commercially for the combustion of coal. In Illinois, this technology is valuable because it allows the combustion of Illinois high sulfur coal without pollution of the atmosphere with vast quantities of sulfur oxides. In FBC, coal is mixed with limestone or dolomite either before injection into the combustion

G. B. Dreher; W. R. Roy; J. D. Steele

1992-01-01

392

Method and equipment for treatment of fuel for fluidized bed combustion  

SciTech Connect

The invention relates to the method and equipment for treatment of fuel for fluidized bed combustion, which includes drying, classification and crushing of the fuel. The method for treatment of fuel comprises mixing the fuel with hot ash removed from the fluidized bed combustor and drying said mixture in a fluidized bed dryer in which the velocity of the fluidization fluid equals or is lower than the minimum fluidization velocity of particles in the fluidized bed combustor. The equipment for treatment of fuel comprises a bunker, crusher and dryer, comprising a fluidized bed dryer provided with appropriate piping for interconnection of the fluidized bed dryer, fluidized bed combuster, fuel bunker and crusher.

Beranek, J.; Cermak, J.; Dobrozemsky, J.; Fibinger, V.

1982-04-20

393

Method and equipment for treatment of fuel for fluidized bed combustion  

SciTech Connect

The invention relates to the method and equipment for treatment of fuel for fluidized bed combustion, which includes drying, classification and crushing of the fuel. The method for treatment of fuel comprises mixing the fuel with hot ash removed from the fluidized bed combustor and drying said mixture in a fluidized bed dryer in which the velocity of the fluidization fluid equals or is lower than the minimum fluidization velocity of particles in the fluidized bed combustor. The equipment for treatment of fuel comprises a bunker, crusher and dryer, comprising a fluidized bed dryer provided with appropriate piping for interconnection of the fluidized bed dryer, fluidized bed combustor, fuel bunker and crusher.

Beranek, J.; Dobrozemsky, J.; Fibinger, V.; Germak, J.

1983-11-15

394

Fluidized bed combustion picks up steam  

SciTech Connect

Industrial interest in fluidized-bed combustion (FBC) continues, although the technology has been slow to enter the marketplace. Two FBC pilot plants funded by DOE and one commercial size project are in operation. FBC designs and commercial warranties are already available from the boiler industry, but 1981 was the first year to see significant numbers of privately-funded orders, now numbering 38 out of 50 boilers. Manufacturers are working on a universal boiler able to accept any fuel, but potential users are wary of new technology without a long-term demonstration of reliability and economics. There is interest in second generation designs, a new shallow-bed design suitable for retrofitting, and circulating bed types that decouple the combustion system from the heat removal system. (DCK)

Lawn, J.

1982-02-01

395

Electromechanics of fluidized beds of nanoparticles  

NASA Astrophysics Data System (ADS)

The electromechanical behavior of a gas-fluidized bed of insulating silica nanoparticles is investigated. When fluidized by gas, these nanoparticles form highly porous agglomerates of size of the order of hundreds of microns, which gives rise to a nonbubbling fluidization regime. Bed expansion is enhanced by an imposed alternating electric field for oscillation frequencies in the range between tens and hundreds of hertzs and field strengths of about 1kV/cm . Nanoparticle agglomerates are naturally charged and experience forced oscillations that cause an increase of the gas flow shear on their surface. As a consequence, the agglomerate size is expected to decrease, which can explain the observed behavior. A model based on the balance between attractive and flow shear forces is presented that accounts for agglomerate size reduction as the strength of the field is increased.

Espin, M. J.; Valverde, J. M.; Quintanilla, M. A. S.; Castellanos, A.

2009-01-01

396

Advanced control strategies for fluidized bed dryers  

SciTech Connect

Generating the best possible control strategy comprises a necessity for industrial processes, by virtue of product quality, cost reduction and design simplicity. Three different control approaches, namely an Input-Output linearizing, a fuzzy logic and a PID controller, are evaluated for the control of a fluidized bed dryer, a typical non-linear drying process of wide applicability. Based on several closed loop characteristics such as settling times, maximum overshoots and dynamic performance criteria such as IAE, ISE and ITAE, it is shown that the Input-Output linearizing and the fuzzy logic controller exhibit a better performance compared to the PID controller tuned optimally with respect to IAE, for a wide range of disturbances; yet, the relevant advantage of the fuzzy logic over the conventional nonlinear controller issues upon its design simplicity. Typical load rejection and set-point tracking examples are given to illustrate the effectiveness of the proposed approach.

Siettos, C.I.; Kiranoudis, C.T.; Bafas, G.V.

1999-11-01

397

Fuzzy control of a fluidized bed dryer  

SciTech Connect

Fluidized bed dryers are utilized in almost every area of drying applications and therefore improved control strategies are always of great interest. The nonlinear character of the process, exhibited in the mathematical model and the open loop analysis, implies that a fuzzy logic controller is appropriate because, in contrast with conventional control schemes, fuzzy control inherently compensates for process nonlinearities and exhibits more robust behavior. In this study, a fuzzy logic controller is proposed; its design is based on a heuristic approach and its performance is compared against a conventional PI controller for a variety of responses. It is shown that the fuzzy controller exhibits a remarkable dynamic behavior, equivalent if not better than the PI controller, for a wide range of disturbances. In addition, the proposed fuzzy controller seems to be less sensitive to the nonlinearities of the process, achieves energy savings and enables MIMO control.

Taprantzis, A.V.; Siettos, C.I.; Bafas, G.V. [National Technical Univ., Athens (Greece). Dept. of Chemical Engineering

1997-05-01

398

Collisions in a liquid fluidized bed  

NASA Astrophysics Data System (ADS)

Collisional phenomena in a liquid fluidized bed were studied in terms of two parameters: the collision frequency and the coefficient of restitution. Experimental measurements of these parameters were conducted by particle tracking in an index-matched array. Collision detection was based on the use of a peak acceleration threshold of the instantaneous speed of dark tracers. The measurements of collision frequency were compared with the theoretical expression derived from the kinetic theory for granular flow (KTGF). The normal and tangential restitution coefficients were measured from the trajectories before and after contact for both particle-particle and particle-wall collisions. A comparison with previous theoretical and experimental works is presented and discussed.

Aguilar-Corona, Alicia; Zenit, Roberto; Masbernat, Olivier

2009-11-01

399

Fluidized bed boiler having a segmented grate  

DOEpatents

A fluidized bed furnace (10) is provided having a perforate grate (9) within a housing which supports a bed of particulate material including some combustibles. The grate is divided into a plurality of segments (E2-E6, SH1-SH5, RH1-RH5), with the airflow to each segment being independently controlled. Some of the segments have evaporating surface imbedded in the particulate material above them, while other segments are below superheater surface or reheater surface. Some of the segments (E1, E7) have no surface above them, and there are ignitor combustors (32, 34) directed to fire into the segments, for fast startup of the furnace without causing damage to any heating surface.

Waryasz, Richard E. (Longmeadow, MA)

1984-01-01

400

Solids feed nozzle for fluidized bed  

DOEpatents

The vertical fuel pipe of a fluidized bed extends up through the perforated support structure of the bed to discharge granulated solid fuel into the expanded bed. A cap, as a deflecting structure, is supported above the discharge of the fuel pipe and is shaped and arranged to divert the carrier fluid and granulated fuel into the combusting bed. The diverter structure is spaced above the end of the fuel pipe and provided with a configuration on its underside to form a venturi section which generates a low pressure in the stream into which the granules of solid fuel are drawn to lengthen their residence time in the combustion zone of the bed adjacent the fuel pipe.

Zielinski, Edward A. (Harwinton, CT) [Harwinton, CT

1982-01-01

401

Heat transfer to horizontal tubes immersed in a fluidized-bed combustor  

Microsoft Academic Search

Experiments were carried out to measure the heat transfer rates to water-cooled horizontal tubes immersed in an atmospheric fluidized-bed combustor burning North Dakota lignite. The effect of bed temperature (T\\/sub B\\/ = 587 to 1205K), particle size (anti d\\/sub p\\/ = 0.544 to 2.335 mm), and fluidizing velocity (U = 0.73 to 2.58 m\\/s) on the heat transfer rate to

N. S. Grewal; J. Menart; D. R. Hajicek; B. J. Zobeck

1986-01-01

402

Studies Toward Improved Techniques for Gasifying Coal.  

National Technical Information Service (NTIS)

Studies have been conducted in the following five areas: high velocity fluidized beds; flash hydrogenation of coal; agglomerating fluidized beds; the Godel Phenomenon; and flowsheeting and system studies. A test stand with three fast beds, in heights of 2...

A. M. Squires J. Yerushalmi R. A. Graff

1976-01-01

403

Proceedings of the Workshop on Utility/Industrial Implementation of Fluidized-Bed Combustion Systems, Atlanta, Georgia, April 27--28, 1976.  

National Technical Information Service (NTIS)

ERDA is involved in R and D to use coal in a form that is environmentally safe and efficient. Direct combustion is the least costly way of using coal, and fluidized-bed combustion (FBC) appears to be the most promising approach. FBC can use coal of any su...

1976-01-01

404

JPL in-house fluidized-bed reactor research  

NASA Technical Reports Server (NTRS)

Fluidized bed reactor research techniques for fabrication of quartz linears was reviewed. Silane pyrolysis was employed in this fabrication study. Metallic contaminant levels in the silicon particles were below levels detectable by emission spectroscopy.

Rohatgi, N. K.

1984-01-01

405

Fluidized-Bed Coating with Organic and Inorganic Materials.  

National Technical Information Service (NTIS)

The report reviews the present technology of fluidizedbed coating processes. The first part deals with the coating of bulk substrates with organic polymers. The second part describes the use of the fluidized-bed method for obtaining inorganic coatings on ...

W. M. Goldberger

1964-01-01

406

Kinetic behavior of solid particles in fluidized beds. Final report.  

National Technical Information Service (NTIS)

The overall objectives of this project are to develop experimental techniques for measuring the forces of fluidized particles, and to predict the solid-gas performance in fluidized beds by using data analysis system, and by elucidating the intrinsic mecha...

H. O. Kono

1990-01-01

407

Load control in low-power fluidized bed boilers  

NASA Astrophysics Data System (ADS)

A thermal engineering analysis of a new method of load control in low-power fluidized bed boilers is cariied out. The method ensures smooth control and does not require heat-transfer surfaces to be located inside the furnace.

Teplitskii, Yu. S.; Dobkin, S. M.

1995-01-01

408

Biological reduction of nitrate wastewater using fluidized-bed bioreactors  

SciTech Connect

There are a number of nitrate-containing wastewater sources, as concentrated as 30 wt % NO/sub 3//sup -/ and as large as 2000 m/sup 3//d, in the nuclear fuel cycle as well as in many commercial processes such as fertilizer production, paper manufacturing, and metal finishing. These nitrate-containing wastewater sources can be successfully biologically denitrified to meet discharge standards in the range of 10 to 20 gN(NO/sub 3//sup -/)/m/sup 3/ by the use of a fluidized-bed bioreactor. The major strain of denitrification bacteria is Pseudomonas which was derived from garden soil. In the fluidized-bed bioreactor the bacteria are allowed to attach to 0.25 to 0.50-mm-diam coal particles, which are fluidized by the upward flow of influent wastewater. Maintaining the bacteria-to-coal weight ratio at approximately 1:10 results in a bioreactor bacteria loading of greater than 20,000 g/m/sup 3/. A description is given of the results of two biodenitrification R and D pilot plant programs based on the use of fluidized bioreactors capable of operating at nitrate levels up to 7000 g/m/sup 3/ and achieving denitrification rates as high as 80 gN(NO/sub 3//sup -/)/d per liter of empty bioreactor volume. The first of these pilot plant programs consisted of two 0.2-m-diam bioreactors, each with a height of 6.3 m and a volume of 208 liters, operating in series. The second pilot plant was used to determine the diameter dependence of the reactors by using a 0.5-m-diam reactor with a height of 6.3 m and a volume of 1200 liters. These pilot plants operated for a period of six months and two months respectively, while using both a synthetic waste and the actual waste from a gaseous diffusion plant operated by Goodyear Atomic Corporation.

Walker, J.F. Jr.; Hancher, C.W.; Patton, B.D.; Kowalchuk, M.

1981-01-01

409

Velocity fluctuations in a low-Reynolds-number fluidized bed  

Microsoft Academic Search

The velocity fluctuations of particles in a low-Reynolds-number fluidized bed have important similarities and differences with the velocity fluctuations in a low-Reynolds- number sedimenting suspension. We show that, like sedimentation, the velocity fluctuations in a fluidized bed are described well by the balance between density fluctuations due to Poisson statistics and Stokes drag. However, unlike sedimentation, the correlation length of

T EE; P. J. M UCHA; M. P. B RENNER

2008-01-01

410

Control of bed height in a fluidized bed gasification system  

DOEpatents

In a fluidized bed apparatus a method for controlling the height of the fdized bed, taking into account variations in the density of the bed. The method comprises taking simultaneous differential pressure measurements at different vertical elevations within the vessel, averaging the differential pressures, determining an average fluidized bed density, then periodically calculating a weighting factor. The weighting factor is used in the determination of the actual bed height which is used in controlling the fluidizing means.

Mehta, Gautam I. (Greensburg, PA); Rogers, Lynn M. (Export, PA)

1983-12-20

411

Electrostatic charge generation in gas–solid fluidized beds  

Microsoft Academic Search

An on-line measurement technique was developed by applying the Faraday cup method to study the mechanism of charge generation inside gas–solid fluidized beds. The net charges generated inside the fluidized bed due to particle–gas contacting and gas ionization are examined. For the range of conditions studied, particle–gas contact and gas ionization have negligible effects on the particle charging mechanism. On

Poupak Mehrani; Hsiaotao T. Bi; John R. Grace

2005-01-01

412

EFFECT OF SO2 EMISSION REQUIREMENTS ON FLUIDIZED-BED COMBUSTION SYSTEMS: PRELIMINARY TECHNICAL/ECONOMIC ASSESSMENT  

EPA Science Inventory

The report gives results of a preliminary technical/economic evaluation to project the impact of SO2 control requirements (up to 90% control) on the capital and energy costs of atmospheric-pressure and pressurized fluidized-bed combustion (AFBC and PFBC) power plants. Ability of ...

413

ESTABLISHMENT OF AN ENVIRONMENTAL CONTROL TECHNOLOGY LABORATORY WITH A CIRCULATING FLUIDIZED-BED COMBUSTION SYSTEM  

SciTech Connect

This report is to present the progress made on the project ''Establishment of an Environmental Control Technology Laboratory (ECTL) with a Circulating Fluidized-Bed Combustion (CFBC) System'' during the period January 1, 2005 through March 31, 2005. The following tasks have been completed. First, the renovation of the new Combustion Laboratory is nearly complete, and the construction of the Circulating Fluidized-Bed (CFB) Combustor Building is in the final stages. Second, the fabrication and manufacture of the CFBC Facility is being discussed with a potential contractor. Discussions with potential contactor regarding the availability of materials and current machining capabilities have resulted in the modification of the original designs. The selection of the fabrication contractor for the CFBC Facility is expected during the next quarter. Third, co-firing experiments conducted with coal and chicken waste have been initiated in the laboratory-scale simulated fluidized-bed facility. The experimental results from this study are presented in this report. Finally, the proposed work for the next quarter is described in this report.

Wei-Ping Pan; Andy Wu; John T. Riley

2005-04-30

414

ESTABLISHMENT OF AN ENVIRONMENTAL CONTROL TECHNOLOGY LABORATORY WITH A CIRCULATING FLUIDIZED-BED COMBUSTION SYSTEM  

SciTech Connect

This purpose of this report is to present the progress made on the project ''Establishment of an Environmental Control Technology Laboratory (ECTL) with a Circulating Fluidized-Bed Combustion (CFBC) System'' during the period April 1, 2005 through June 30, 2005. The following tasks have been completed. First, the new Combustion Laboratory was occupied on June 15, 2005, and the construction of the Circulating Fluidized-Bed (CFB) Combustor Building is in the final painting stage. Second, the fabrication and manufacturing contract for the CFBC Facility was awarded to Sterling Boiler & Mechanical, Inc. of Evansville, Indiana. Sterling is manufacturing the assembly and component parts of the CFBC system. The erection of the CFBC system is expected to start September 1, 2005. Third, mercury emissions from the cofiring of coal and chicken waste was studied experimentally in the laboratory-scale simulated fluidized-bed combustion facility. The experimental results from this study are presented in this report. Finally, the proposed work for the next quarter is described.

Wei-Ping Pan; Andy Wu; John T. Riley

2005-07-30

415

Multistage fluidized bed reactor performance characterization for adsorption of carbon dioxide  

SciTech Connect

Carbon dioxide and its different compounds are generated as primary greenhouse gases from the flue gases of coal-fired thermal power plants, boilers, and other stationary combustion processes. This greenhouse gas causes global warming after being emitted to the environment. To deal with this problem, a new dry scrubbing process was tested in this study. A three-stage countercurrent fluidized bed adsorber was developed, designed, and fabricated. It was used as a removal apparatus and operated in a continuous regime for the two-phase system. The height of each stage was 0.30 m, and the inner diameter was 0.10 m. The paper presents the removal of CO{sub 2} from gas mixtures by chemical sorption on porous granular calcium oxide particles in the reactor at ambient temperature. The advantages of a multistage fluidized bed reactor for high mass transfer and high gas-solid contact can enhance the removal of the gas when using a dry method. The effects of the operating parameters such as sorbent, superficial gas velocity, and the Weir height on CO{sub 2} removal efficiency in the multistage fluidized bed were investigated. The results indicate that the removal efficiency of the carbon dioxide was around 71% at a high solid flow rate corresponding to lower gas velocity at room temperature. In comparison with wet scrubbers, this dry process appears to have lower cost, less complicated configuration, and simpler disposal of used sorbent. The results in this study assume importance from the perspective of use of a multistage fluidized bed adsorber for control of gaseous pollutants at high temperature.

Roy, S.; Mohanty, C.R.; Meikap, B.C. [Indian Institute of Technology, Kharagpur (India). Dept. of Chemical Engineering

2009-12-15

416

Particle pressures in fluidized beds. First year annual report  

SciTech Connect

This is an experimental project to make detailed measurements of the particle pressures generated in fluidized beds. The focus lies in two principle areas: (1) the particle pressure distribution around single bubbles rising in a two-dimensional gas-fluidized bed and (2) the particle pressures measured in liquid-fluidized beds. This first year has largely been to constructing the experiments The design of the particle pressure probe has been improved and tested. A two-dimensional gas-fluidized bed has been constructed in order to measure the particle pressure generated around injected bubbles. The probe is also being adapted to work in a liquid fluidized bed. Finally, a two-dimensional liquid fluidized bed is also under construction. Preliminary measurements show that the majority of the particle pressures are generated in the wake of a bubble. However, the particle pressures generated in the liquid bed appear to be extremely small. Finally, while not directly associated with the particle pressure studies, some NERSC supercomputer time was granted alongside this project. This is being used to make large scale computer simulation of the flow of granular materials in hoppers.

Campbell, C.S.; Rahman, K.; Hu, X.; Jin, C.; Potapov, A.V.

1992-09-01

417

EERC pilot CRBC shows influence of coal properties. [Energy and Environmental Research Center  

Microsoft Academic Search

Thermal and environmental performance and operating costs of an atmospheric circulating fluidized-bed combustor (CFBC) are functions of operating conditions, design parameters, and fuel properties. Knowledge of specific coal properties is critical in the design phase of a CFBC. Full understanding of other properties of coal is more critical during operation. Tests to this end were conducted at the University of

M. D. Mann; D. R. Hajucek; A. K. Henderson; T. A. Moe

1993-01-01

418

Monitoring Fluidized Bed Drying of Pharmaceutical Granules  

PubMed Central

Placebo granules consisting of lactose monohydrate, corn starch, and polyvinylpyrrolidone were prepared using de-ionized water in a high-shear mixer and dried in a conical fluidized bed dryer at various superficial gas velocities. Acoustic, vibration, and pressure data obtained over the course of drying was analyzed using various statistical, frequency, fractal, and chaos techniques. Traditional monitoring methods were also used for reference. Analysis of the vibration data showed that the acceleration levels decreased during drying and reached a plateau once the granules had reached a final moisture content of 1–2 wt.%; this plateau did not differ significantly between superficial gas velocities, indicating a potential criterion to support drying endpoint identification. Acoustic emissions could not reliably identify the drying endpoint. However, high kurtosis values of acoustic emissions measured in the filtered air exhaust corresponded to high entrainment rates. This could be used for process control to adjust the fluidization gas velocity to allow drying to continue rapidly while minimizing entrainment and possible product losses.

Bojarra, Megan

2010-01-01

419

Silicon production in a fluidized bed reactor  

NASA Technical Reports Server (NTRS)

Part of the development effort of the JPL in-house technology involved in the Flat-Plate Solar Array (FSA) Project was the investigation of a low-cost process to produce semiconductor-grade silicon for terrestrial photovoltaic cell applications. The process selected was based on pyrolysis of silane in a fluidized-bed reactor (FBR). Following initial investigations involving 1- and 2-in. diameter reactors, a 6-in. diameter, engineering-scale FBR was constructed to establish reactor performance, mechanism of silicon deposition, product morphology, and product purity. The overall mass balance for all experiments indicates that more than 90% of the total silicon fed into the reactor is deposited on silicon seed particles and the remaining 10% becomes elutriated fines. Silicon production rates were demonstrated of 1.5 kg/h at 30% silane concentration and 3.5 kg/h at 80% silane concentration. The mechanism of silicon deposition is described by a six-path process: heterogeneous deposition, homogeneous decomposition, coalescence, coagulation, scavenging, and heterogeneous growth on fines. The bulk of the growth silicon layer appears to be made up of small diameter particles. This product morphology lends support to the concept of the scavenging of homogeneously nucleated silicon.

Rohatgi, N. K.

1986-01-01

420

Treating exhaust gas from a pressurized fluidized bed reaction system  

DOEpatents

Hot gases from a pressurized fluidized bed reactor system are purified. Under super atmospheric pressure conditions hot exhaust gases are passed through a particle separator, forming a filtrate cake on the surface of the separator, and a reducing agent--such as an NO{sub x} reducing agent (like ammonia)--is introduced into the exhaust gases just prior to or just after particle separation. The retention time of the introduced reducing agent is enhanced by providing a low gas velocity (e.g. about 1--20 cm/s) during passage of the gas through the filtrate cake while at super atmospheric pressure. Separation takes place within a distinct pressure vessel, the interior of which is at a pressure of about 2--100 bar, and introduction of reducing agent can take place at multiple locations (one associated with each filter element in the pressure vessel), or at one or more locations just prior to passage of clean gas out of the pressure vessel (typically passed to a turbine). 8 figs.

Isaksson, J.; Koskinen, J.

1995-08-22

421

10 CFR 503.10 - Use of fluidized bed combustion not feasible-general requirement for permanent exemptions.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Use of fluidized bed combustion not feasible-general...Exemptions § 503.10 Use of fluidized bed combustion not feasibleâgeneral...basis that use of a method of fluidized bed combustion of an alternate...

2010-01-01

422

10 CFR 503.10 - Use of fluidized bed combustion not feasible-general requirement for permanent exemptions.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Use of fluidized bed combustion not feasible-general...Exemptions § 503.10 Use of fluidized bed combustion not feasibleâgeneral...basis that use of a method of fluidized bed combustion of an alternate...

2009-01-01

423

Technical and economic assessment of fluidized-bed-augmented compressed air energy-storage system. Volume 2: Introduction and technology assessment  

Microsoft Academic Search

The results are described of a study subcontracted by PNL to the United Technologies Research Center on the engineering feasibility and economics of a CAES concept which uses a coal fired, fluidized bed combustor (FBC) to heat the air being returned from storage during the power production cycle. By burning coal instead of fuel oil, the CAES\\/FBC concept can completely

A. J. Giramonti; R. D. Lessard; D. Merrick; M. J. Hobson

1981-01-01

424

Packaged fluidized bed boiler incorporates steam calorimeter to maintain steam quality. [Central Soya processing plant in Marian, Ohio  

SciTech Connect

Engineers at the Central Soya processing plant in Marion, Ohio were faced with the problem of upgrading or replacing two 20 y old coal-fired steam boilers. A boiler design was chosen which could fire all types of coal, oil, and natural gas - either individually or simultaneously. Boiler efficiency and environmental quality were enhanced by several design features. By incorporating a throttling steam calorimeter into the boiler design, accurate measurements of the moisture of the motive steam produced were facilitated. To achieve high combustion efficiency, a concave fluidized bed was used to control the circulation of solids within the bed. In addition to environmental compliance, the fluidized bed boiler has saved 1000 tons of coal over a 2 y period at a production capacity of 4000 lb steam/h. System efficiency has increased from 75% to 85%. The conversion has provided both environmental and economic justification, while providing more reliable service with minimal operating and operating costs.

Toy, D.A.

1984-04-01

425

Establishment of an Environmental Control Technology Laboratory with a Circulating Fluidized-Bed Combustion System  

SciTech Connect

On February 14, 2002, President Bush announced the Clear Skies Initiative, a legislative proposal to control the emissions of nitrogen oxides (NO{sub x}), sulfur dioxide (SO{sub 2}), and mercury from power plants. In response to this initiative, the National Energy Technology Laboratory organized a Combustion Technology University Alliance and hosted a Solid Fuel Combustion Technology Alliance Workshop. The workshop identified multi-pollutant control; improved sorbents and catalysts; mercury monitoring and capture; and improved understanding of the underlying reaction chemistry occurring during combustion as the most pressing research needs related to controlling environmental emissions from fossil-fueled power plants. The Environmental Control Technology Laboratory will help meet these challenges and offer solutions for problems associated with emissions from fossil-fueled power plants. The goal of this project was to develop the capability and technology database needed to support municipal, regional, and national electric power generating facilities to improve the efficiency of operation and solve operational and environmental problems. In order to effectively provide the scientific data and the methodologies required to address these issues, the project included the following aspects: (1) Establishing an Environmental Control Technology Laboratory using a laboratory-scale, simulated fluidized-bed combustion (FBC) system; (2) Designing, constructing, and operating a bench-scale (0.6 MW{sub th}), circulating fluidized-bed combustion (CFBC) system as the main component of the Environmental Control Technology Laboratory; (3) Developing a combustion technology for co-firing municipal solid waste (MSW), agricultural waste, and refuse-derived fuel (RDF) with high sulfur coals; (4) Developing a control strategy for gaseous emissions, including NO{sub x}, SO{sub 2}, organic compounds, and heavy metals; and (5) Developing new mercury capturing sorbents and new particulate filtration technologies. Major tasks during this period of the funded project's timeframe included: (1) Conducting pretests on a laboratory-scale simulated FBC system; (2) Completing detailed design of the bench-scale CFBC system; (3) Contracting potential bidders to fabricate of the component parts of CFBC system; (4) Assembling CFBC parts and integrating system; (5) Resolving problems identified during pretests; (6) Testing with available Powder River Basin (PRB) coal and co-firing of PRB coal with first wood pallet and then chicken wastes; and (7) Tuning of CFBC load. Following construction system and start-up of this 0.6 MW CFBC system, a variety of combustion tests using a wide range of fuels (high-sulfur coals, low-rank coals, MSW, agricultural waste, and RDF) under varying conditions were performed to analyze and monitor air pollutant emissions. Data for atmospheric pollutants and the methodologies required to reduce pollutant emissions were provided. Integration with a selective catalytic reduction (SCR) slipstream unit did mimic the effect of flue gas composition, including trace metals, on the performance of the SCR catalyst to be investigated. In addition, the following activities were also conducted: (1) Developed advanced mercury oxidant and adsorption additives; (2) Performed laboratory-scale tests on oxygen-fuel combustion and chemical looping combustion; and (3) Conducted statistical analysis of mercury emissions in a full-scale CFBC system.

Wei-Ping Pan; Yan Cao; John Smith

2008-05-31

426

Staged combustion of rice straw in a fluidized bed  

SciTech Connect

Staged combustion of rice straw has been investigated using an atmospheric bubbling fluidized bed combustor. The combustor has a 300 mm ID and a 3300 mm height. Secondary air was introduced in the freeboard at 1500 mm above the primary air distributor. Rice straw was fed as cylindrical pellets of a 12 mm diameter and 10-15 mm lengths. The obtained results indicate that staged combustion appears an effective technique to reduce NO{sub x} emissions, in particular, at higher operating temperatures. Typically, at 850 C bed temperature, NO{sub x} concentration is reduced by about 50% when 30% of fed air is introduced as secondary air. Staged operation has a slight, non-monotonic effect on SO{sub 2} emission. Combustion efficiency improves with increasing secondary air ratio reaching a maximum value that is mainly attributed to a reduction in fixed carbon loss. With further increase in secondary air ratio, combustion efficiency, however, decreases again since entrained fixed carbon and exhausted carbon monoxide tend to increase. The range of secondary air ratio, over which combustion efficiency improves, expands at higher operating temperatures. (author)

Okasha, F. [Department of Mechanical Engineering, Mansoura University (Egypt)

2007-10-15

427

Concentration and Velocity Gradients in Fluidized Beds  

NASA Technical Reports Server (NTRS)

In this work we focus on the height dependence of particle concentration, average velocity components, fluctuations in these velocities and, with the flow turned off, the sedimentation velocity. The latter quantities are measured using Particle Imaging Velocimetry (PIV). The PIV technique uses a 1-megapixel camera to capture two time-displaced images of particles in the bed. The depth of field of the imaging system is approximately 0.5 cm. The camera images a region with characteristic length of 2.6 cm for the small particles and 4.7 cm. for the large particles. The local direction of particle flow is determined by calculating the correlation function for sub-regions of 32 x 32 pixels. The velocity vector map is created from this correlation function using the time between images (we use 15 to 30 ms). The software is sensitive variations of 1/64th of a pixel. We produce velocity maps at various heights, each consisting of 3844 velocities. We break this map into three vertical zones for increased height information. The concentration profile is measured using an expanded (1 cm diameter) linearly polarized HeNe Laser incident on the fluidized bed. A COHU camera (gamma=1, AGC off) with a lens and a polarizer images the transmitted linearly polarized light to minimize the effects of multiply scattered light. The intensity profile (640 X 480 pixels) is well described by a Gaussian fit and the height of the Gaussian is used to characterize the concentration. This value is compared to the heights found for known concentrations. The sedimentation velocity is estimated using by imaging a region near the bottom of the bed and using PIV to measure the velocity as a function of time. With a nearly uniform concentration profile, the time can be converted to height information. The stable fluidized beds are made from large pseudo-monodisperse particles (silica spheres with radii (250-300) microns and (425-500) microns) dispersed in a glycerin/water mix. The Peclet number is sufficiently large that Brownian motion of the particles can be ignored and the Reynolds number sufficiently small that particle inertia is negligible. A packed particle bed is used to randomize and disperse the flowing fluid introduced by a peristaltic pump. The bed itself is a rectangular glass cell 8 cm wide (x), 0.8 cm deep and a height of 30.5 cm (z). The depth of field of the camera is approximately 0.5 cm so depth information is averaged. Over flow fluid is returned to the reservoir making a closed loop system. In these experiments the particles form a sediment approximately 5.7 cm high with the pump off and expand to 22 cm with the pump on. For the smaller particles the pump velocity is .5 millimeters per second and 1.1 millimeters per second for the large particles. At this concentration the bed has a very well defined top where particle concentration rapidly drops to zero.

McClymer, James P.

2003-01-01

428

Material handling systems for the fluidized-bed combustion boiler at Rivesville, West Virginia  

NASA Technical Reports Server (NTRS)

The 300,000 lbs/hr steam capacity multicell fluidized-bed boiler (MFB) utilizes complex material handling systems. The material handling systems can be divided into the following areas: (1) coal preparation; transfer and delivery, (2) limestone handling system, (3) fly-ash removal and (4) bed material handling system. Each of the above systems are described in detail and some of the potential problem areas are discussed. A major potential problem that exists is the coal drying system. The coal dryer is designed to use 600 F preheated combustion air as drying medium and the dryer effluent is designed to enter a hot electrostatic precipitator (730 F) after passage through a cyclone. Other problem areas to be discussed include the steam generator coal and limestone feed system which may have operating difficulties with wet coal and/or coal fines.

Branam, J. G.; Rosborough, W. W.

1977-01-01

429

FLUIDIZED BED STEAM REFORMER MONOLITH FORMATION  

SciTech Connect

Fluidized Bed Steam Reforming (FBSR) is being considered as an alternative technology for the immobilization of a wide variety of aqueous high sodium containing radioactive wastes at various DOE facilities in the United States. The addition of clay, charcoal, and a catalyst as co-reactants converts aqueous Low Activity Wastes (LAW) to a granular or ''mineralized'' waste form while converting organic components to CO{sub 2} and steam, and nitrate/nitrite components, if any, to N{sub 2}. The waste form produced is a multiphase mineral assemblage of Na-Al-Si (NAS) feldspathoid minerals with cage-like structures that atomically bond radionuclides like Tc-99 and anions such as SO{sub 4}, I, F, and Cl. The granular product has been shown to be as durable as LAW glass. Shallow land burial requires that the mineralized waste form be able to sustain the weight of soil overburden and potential intrusion by future generations. The strength requirement necessitates binding the granular product into a monolith. FBSR mineral products were formulated into a variety of monoliths including various cements, Ceramicrete, and hydroceramics. All but one of the nine monoliths tested met the <2g/m{sup 2} durability specification for Na and Re (simulant for Tc-99) when tested using the Product Consistency Test (PCT; ASTM C1285). Of the nine monoliths tested the cements produced with 80-87 wt% FBSR product, the Ceramicrete, and the hydroceramic produced with 83.3 wt% FBSR product, met the compressive strength and durability requirements for an LAW waste form.

Jantzen, C

2006-12-22

430

Waste tire fluidized bed combustion boiler project  

SciTech Connect

The objective was to commercially demonstrate a fluidized bed combustion (F.B.C.) system that could convert waste tires into steam energy at a convenience level approximately that of oil or gas-fired boilers. In order to burn tires in a F.B.C. unit, the tires must first be chopped into a maximum size of four inches by four inches. This was readily accomplished in a tire chopper modified for multi-pass operation. The chopper could be mounted on a truck or trailer and use gasoline or other fuels making it suitable for mobile operation. A test program was conducted to determine performance and design criteria, which were used to specify a commercial scale steam generation demonstration unit. It was found that 100% of the heat of combustion available in tires can be released in a F.B.C. unit. Tires must be combusted at 775 +- 25/sup 0/C to provide for fiberglass removal. Unburned carbon black along with fiberglass, zinc oxide, bed fines and scrap wire would have to be landfilled. Sulfur dioxide and nitrogen oxide emissions would be below the limits imposed by the Michigan Department of Natural Resources. Particulate emissions downstream of the cyclone would have to be limited by some system such as a bag house. A site was prepared for the pilot model site at National-Standard Lake Street Plant Building No. 6 in Niles, Michigan. The tire chopper and most of the auxiliary equipment was installed. Before contracts were awarded to construct the F.B.C. unit, a revised financial analysis showed that the investment required for the F.B.C. unit made the entire system uneconomical. Although the operating costs of the waste tire system was considerably less than that of gas or oil fired boilers, the large initial investment for the system made the payback period 12 to 18 years.

Not Available

1984-03-01

431

An investigation of particle mixing in a gas-fluidized bed  

NASA Technical Reports Server (NTRS)

Mechanism for particle movement in gas-fluidized beds was studied both from the theoretical and experimental points of view. In a two-dimensional fluidized bed particle trajectories were photographed when a bubble passed through.

Carlson, R. E.; Gabor, J. D.

1968-01-01

432

NO(sub x) reduction in pressurized fluidized-bed combustion.  

National Technical Information Service (NTIS)

Batch combustion experiments were performed in a small bubbling fluidized-bed reactor with the objective of establishing the cause of reduced NO(sub x) emissions from pressurized fluidized bed combustion (PFBC). All variables except for pressure were kept...

P. H. Wallman R. C. J. Carlsson B. Leckner

1992-01-01

433

Co-firing waste materials in an advanced pressurized fluidized-bed combustor  

SciTech Connect

A study has been undertaken to investigate the technical and economic feasibility of co-firing a pressurized fluidized-bed combustor (PFBC) with coal and municipal or industrial wastes. Focus was placed on the production of electricity and the efficient disposal of wastes for application in a central power station and distributed locations. Wastes considered for co-firing include municipal solid waste (MSW), municipal sewage sludge, and industrial de-inking sludge. Issues concerning waste material preparation and feed, PFBC operation, plant emissions, and regulations are addressed. This paper describes the results of the performance evaluation completed as part of this study, and provides recommendations for further evaluation.

Rubow, L.N.; DeLallo, M.R.; Zaharchuk, R.

1994-10-01

434

Concept for a super-clean super-efficient pressurized fluidized-bed combustion system  

SciTech Connect

A paper study for a highly efficient, environmentally benign, coal-fired electric power generation system, is presented. This system falls in the category of pressurized fluidized-bed combustion (PFBC) systems which has been dubbed super-clean super-efficient PFBC`s. The system presented starts with the second-generation PFBC concept and adds on advanced gas turbine, a solid oxide fuel cell, a supercritical steam cycle, a second low-temperature rankine cycle which pulls energy from the steam condenser, and inlet air cooling. The thermodynamic efficiency of the system is calculated to be 61.8 percent based on higher heating value (HHV).

Mollott, D.J.; Reed, M.

1994-12-31

435

Incineration of paper sludge in a prototype vortexing fluidized bed combustor.  

PubMed

All experiments were carried out in a prototype vortexing fluidized bed combustor (VFBC). The dimension of the combustion chamber is 0.7 x 1.4 x 2 m, and the freeboard section is 1 m i.d. and 4 m in height. Paper sludge was used as the feeding material. Two types of coal particles were employed as the supplementary fuel. In order to understand the characteristics of the VFBC system for paper sludge incineration, the effect of various operating parameters, such as the primary airflow, excess air ratio, and secondary airflow rates, on temperature distribution, ash elutriation, combustion efficiency, and pollutant emissions were investigated. PMID:11321911

Chyang, C S; Liu, C Y; Chang, Y D

2001-04-01

436

Experimental and theoretical study of a micro-fluidized bed  

NASA Astrophysics Data System (ADS)

Large industrial scale fluidized beds (FBs) have been widely used because of their ability to greatly enhance mixing and both heat and mass transfer. This suggests that fluidized beds may offer a means of overcoming the poor mixing and transport characteristics of microfluidic devices where low Reynolds number flows prevail. We report experimental findings on liquid fluidization in microfluidic channels of 200-400 ?m in size. Excellent fluidization is observed for various particles fluidized in ethanol where surface forces between the particles and the microfluidic channel are weak. In contrast, adhesion of the particles to the walls and subsequent de-fluidization is observed when water is used as the fluidizing medium. These findings demonstrate the importance of surface forces in micro-fluidized beds. We also find that conventional theories are able to explain the impact of surface forces on fluidization and, provided the effect of the walls on the particle packing and porosity is accounted for, the fluidization behavior.

Zivkovic, V.; Kashani, M. N.; Biggs, M. J.

2013-06-01

437

Methods of forming a fluidized bed of circulating particles  

DOEpatents

There is disclosed an apparatus for forming a fluidized bed of circulating particles. In an embodiment, the apparatus includes a bottom portion having a sidewall, the sidewall defining a curvilinear profile, and the bottom portion configured to contain a bed of particles; and a gas inlet configured to produce a column of gas to carry entrained particles therein. There is disclosed a method of forming a fluidized bed of circulating particles. In an embodiment, the method includes positioning particles within a bottom portion having a sidewall, the sidewall defining a curvilinear profile; producing a column of gas directed upwardly through a gas inlet; carrying entrained particles in the column of gas to produce a fountain of particles over the fluidized bed of circulating particles and subside in the particle bed until being directed inwardly into the column of gas within the curvilinear profile.

Marshall, Douglas W. (Blackfoot, ID)

2011-05-24

438

Computational fluid dynamic modeling of fluidized-bed polymerization reactors  

SciTech Connect

Polyethylene is one of the most widely used plastics, and over 60 million tons are produced worldwide every year. Polyethylene is obtained by the catalytic polymerization of ethylene in gas and liquid phase reactors. The gas phase processes are more advantageous, and use fluidized-bed reactors for production of polyethylene. Since they operate so close to the melting point of the polymer, agglomeration is an operational concern in all slurry and gas polymerization processes. Electrostatics and hot spot formation are the main factors that contribute to agglomeration in gas-phase processes. Electrostatic charges in gas phase polymerization fluidized bed reactors are known to influence the bed hydrodynamics, particle elutriation, bubble size, bubble shape etc. Accumulation of electrostatic charges in the fluidized-bed can lead to operational issues. In this work a first-principles electrostatic model is developed and coupled with a multi-fluid computational fluid dynamic (CFD) model to understand the effect of electrostatics on the dynamics of a fluidized-bed. The multi-fluid CFD model for gas-particle flow is based on the kinetic theory of granular flows closures. The electrostatic model is developed based on a fixed, size-dependent charge for each type of particle (catalyst, polymer, polymer fines) phase. The combined CFD model is first verified using simple test cases, validated with experiments and applied to a pilot-scale polymerization fluidized-bed reactor. The CFD model reproduced qualitative trends in particle segregation and entrainment due to electrostatic charges observed in experiments. For the scale up of fluidized bed reactor, filtered models are developed and implemented on pilot scale reactor.

Rokkam, Ram [Ames Laboratory

2012-11-02

439

Internal dust recirculation system for a fluidized bed heat exchanger  

DOEpatents

A fluidized bed heat exchanger in which air is passed through a bed of particulate material containing fuel disposed in a housing. A steam/water natural circulation system is provided in a heat exchange relation to the bed and includes a steam drum disposed adjacent the bed and a tube bank extending between the steam drum and a water drum. The tube bank is located in the path of the effluent gases exiting from the bed and a baffle system is provided to separate the solid particulate matter from the effluent gases. The particulate matter is collected and injected back into the fluidized bed.

Gamble, Robert L. (Wayne, NJ) [Wayne, NJ; Garcia-Mallol, Juan A. (Morristown, NJ) [Morristown, NJ

1981-01-01

440

Fluidization onset and expansion of gas-solid fluidized beds  

SciTech Connect

A simple, mass conservation-based, kinematic model is presented for accurately predicting both the onset of fluidization and the degree of (limit of) bed expansion in bubbling gas-solid fluidized beds. The model is consistant with inception correlations exisiting in the literature. Since the method has a sound physical basis, it might be expected to provide scaling between laboratory-scale fluidized beds and large-scale systems. This scaling ability, however, remains to be demonstrated as does the application to pressurized systems and where the terminal Reynolds numbers exceed 1000, (Archimedes numbers over about 3.2 x 10/sup 5/).

Jones, O.C.; Shin, T.S.

1984-08-01

441

Evaluation of waste pyrolysis characteristics in a pressurized fluidized bed reactor  

Microsoft Academic Search

To obtain the distribution of fuel components to gas, tar and char in a pressurized fluidized bed waste pyrolyzer, experiments were conducted with a laboratory scale fluidized bed reactor. Waste samples were fed batchwise from the top of the reactor into the fluidized bed of silica sand and pyrolyzed by nitrogen\\/nitrogen–O2 gas and the effects of pressure, particle size, heating

Ayumi Ono; Mitsuaki Kurita; Taro Nagashima; Masayuki Horio

2001-01-01

442

The influence of air staging in the reduction of SO 2 by limestone in a fluidized bed combustor  

Microsoft Academic Search

To meet the legislation on limiting NOx and SOx emission from large combustion plants, SO2 emissions may need to be reduced by about 60–70%. The authors' technique for achieving significant reduction in SO2 emissions from combustion systems burning large coals utilizes limestone for in situ reduction of SO2 in fluidized bed combustors. A recent technique for reducing NOx emissions combines

Wasi Z. Khan; Bernard M. Gibbs

1995-01-01

443

Emission characteristics of dioxins, furans and polycyclic aromatic hydrocarbons during fluidized-bed combustion of sewage sludge  

Microsoft Academic Search

Pre-dried sewage sludge with high sulfur content was combusted in an electrically heated lab-scale fluidized-bed incinerator. The emission characteristics of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polycyclic aromatic hydrocarbons (PAHs) were studied. Coal and calcium oxide (CaO) were added during the sewage sludge combustion tests to optimize combustion conditions and control SO2 emission. The results indicated that the flue

Wenyi DENG; Jianhua YAN; Xiaodong LI; Fei WANG; Yong CHI; Shengyong LU

2009-01-01

444

Alkali metal vapor removal from pressurized fluidized-bed combustor flue gas. Annual report, October 1982September 1983  

Microsoft Academic Search

Under the auspices of US Department of Energy, this work supports the program to develop sorbents for the cleanup of gases from pressurized fluidized-bed coal combustion (PFBC) so that these cleaned hot gases can be used to power downstream gas turbines without causing corrosion. A laboratory-scale pressurized test unit was used to continue the alkali-vapor characterization of activated bauxite and

S. H. D. Lee; K. M. Myles; A. A. Jonke

1984-01-01

445

Alkali-metal-vapor removal from pressurized fluidized-bed-combustor flue gas. Annual report, October 1981September 1982  

Microsoft Academic Search

This work supports the program to develop sorbents for the cleanup of gases from pressurized fluidized-bed coal combustion (PFBC) so that the cleaned hot gases can be used to power downstream gas turbines without causing corrosion. A simulated PFBC flue gas containing NaCl vapor was used to characterize activated bauxite and diatomaceous earth at a bed temperature of 905°C and

S. H. D. Lee; K. M. Myles; A. A. Jonke

1983-01-01

446

Pressurized Fluidized Bed Combustion Second-Generation System Research and Development  

SciTech Connect

Research is being conducted under United States Department of Energy (DOE) Contract DE-AC21-86MC21023 to develop a new type of coal-fired plant for electric power generation. This new type of plant--called a Second-Generation or Advanced Pressurized Circulating Fluidized Bed Combustion (APCFB) plant--offers the promise of efficiencies greater than 45% (HHV), with both emissions and a cost of electricity that are significantly lower than conventional pulverized-coal-fired plants with scrubbers. The APCFB plant incorporates the partial gasification of coal in a carbonizer, the combustion of carbonizer char in a pressurized circulating fluidized bed boiler (PCFB), and the combustion of carbonizer syngas in a topping combustor to achieve gas turbine inlet temperatures of 2300 F and higher. A conceptual design was previously prepared for this new type of plant and an economic analysis presented, all based on the use of a Siemens Westinghouse W501F gas turbine with projected carbonizer, PCFB, and topping combustor performance data. Having tested these components at the pilot plant stage, the referenced conceptual design is being updated to reflect more accurate performance predictions together with the use of the more advanced Siemens Westinghouse W501G gas turbine and a conventional 2400 psig/1050 F/1050 F/2-1/2 in. steam turbine. This report describes the updated plant which is projected to have an HHV efficiency of 48% and identifies work completed for the October 2001 through September 2002 time period.

A. Robertson; D. Horazak; R. Newby; H. Goldstein

2002-11-01

447

Coal Power and Combustion. Quarterly Report, October--December 1976.  

National Technical Information Service (NTIS)

In addition to an executive summary and glossary, the following sections are included: Multicell Atmospheric Pressure Fluidized-bed Boiler; Energy Conversion Alternatives Study (ECAS); Pressurized Fluidized-bed Combustor and Turbine Power Generation; Supp...

P. C. White M. B. Neuworth

1976-01-01

448

Establishment of an Environmental Control Technology Laboratory with a Circulating Fluidized-Bed Combustion System  

SciTech Connect

This report is to present the progress made on the project entitled ''Establishment of an Environmental Control Technology Laboratory (ECTL) with a Circulating Fluidized-Bed Combustion (CFBC) System'' during the period January 1, 2007 through March 31, 2007. The effort in this quarter has concentrated on installing the CFBC Facility and for conducting cold fluidization operations tests in the CFBC facility. The assembly of the ash recirculation pipe duct from the cyclones back to the bed area of the combustor, including the upper and lower loop seals was completed. The electric bed pre-heater was installed to heat the fluidizing air as it enters the wind box. The induced draft fan along with its machine base and power supply was received and installed. The flue gas duct from secondary cyclone outlet to induced draft fan inlet was received and installed, as well as the induced fan flue gas discharge duct. Pressure testing from the forced draft fan to the outlet of the induced fan was completed. In related research a pilot-scale halogen addition test was conducted in the empty slipstream reactor (without (Selective Catalytic Reduction) SCR catalyst loading) and the SCR slipstream reactor with two commercial SCR catalysts. The greatest benefits of conducting slipstream tests can be flexible control and isolation of specific factors. This facility is currently used in full-scale utility and will be combined into 0.6MW CFBC in the future. This work attempts to first investigate performance of the SCR catalyst in the flue gas atmosphere when burning Powder River Basin (PRB), including the impact of PRB coal flue gas composition on the reduction of nitrogen oxides (NOx) and the oxidation of elemental mercury (Hg(0)) under SCR conditions. Secondly, the impacts of hydrogen halogens (Hydrogen fluoride (HF), Hydrogen chloride (HCl), Hydrogen Bromide (HBr) and Hydrogen Iodine (HI)) on Hg(0) oxidation and their mechanisms can be explored.

Wei-Ping Pan; Yan Cao; John Smith

2007-03-31

449

On the expansion exponent for gas-solid fluidized beds relative to the rotating fluidized bed reactor  

NASA Astrophysics Data System (ADS)

The 'drift-flux' model of Wallis (1962) was used to develop a simple kinematic model for accurately predicting both the onset of fluidization and the degree of bed expansion in bubbling gas-solid fluidized beds. The model presents unified procedures for all particle terminal Reynolds numbers below 2 x 10 to the 5th, representing Archimedes numbers from zero to over 10 to the 10th. This method can be used to predict fuel bed expansion in the rotating fluidized bed reactor.

Jones, O. C., Jr.; Shin, T. S.

450

Concept for Fluidized Bed Combustion of Consol Char Using a Closed-Cycle Helium Power Plant with an Estimate of the Price of Electric Power. Final Report.  

National Technical Information Service (NTIS)

The Consol process for making synthetic crude oil from coal produces char as a by-product which is an undesirable fuel, but can be burned in a fluidized bed. Instead of using steam as the working fluid, helium was chosen, since a higher working temperatur...

A. Himmelblau J. Norton

1976-01-01

451

Process Costs and Flowsheets, Bed Defluidization Characteristics, Stone Reactivity Changes and Attrition Losses for a Regenerative Fluidized-Bed Combustion Process.  

National Technical Information Service (NTIS)

As a means of significantly reducing the amount of limestone required by the fluidized-bed combustion of coal, a limestone regeneration process has been developed which allows the sorbent to be recycled back to the combustor for reuse. To further the deve...

W. M. Swift J. C. Montagna G. W. Smith E. B. Smyk

1980-01-01

452

Description of emission control using fluidized-bed, heat-exchange technology  

SciTech Connect

Environmental effects of fluidized-bed, waste-heat recovery technology are identified. The report focuses on a particular configuration of fluidized-bed, heat-exchange technology for a hypothetical industrial application. The application is a lead smelter where a fluidized-bed, waste-heat boiler (FBWHB) is used to control environmental pollutants and to produce steam for process use. Basic thermodynamic and kinetic information for the major sulfur dioxide (SO/sub 2/) and NO/sub x/ removal processes is presented and their application to fluidized-bed, waste heat recovery technology is discussed. Particulate control in fluidized-bed heat exchangers is also discussed.

Vogel, G.J.; Grogan, P.J.

1980-06-01

453

Defluidized zones in liquid–solid fluidized beds  

Microsoft Academic Search

Defluidized zones often appear on the distributor plates of liquid–solid fluidized beds. They can lead to hot spots, the formation of undesirable side products or the degradation of products or reactants. In some cases, a solid residue forms and plugs the distributor.Two different techniques were developed to detect defluidized zones. The first technique uses a specially designed collision probe to

C. L Briens; S Barghi

2001-01-01

454

CFD modelling of a liquid–solid fluidized bed  

Microsoft Academic Search

A multifluid Eulerian computational fluid dynamics (CFD) model with granular flow extension is used to simulate a liquid–solid fluidized bed. The numerical simulations are evaluated qualitatively by experimental data from the literature and quantitatively by comparison with new experimental data. The effects of mesh size, time step and convergence criteria are investigated. Varying the coefficient of restitution did not alter

Jack T. Cornelissen; Fariborz Taghipour; Renaud Escudié; Naoko Ellis; John R. Grace

2007-01-01

455

Computation of flow patterns in circulating fluidized beds  

Microsoft Academic Search

This paper reports on flow regimes of dense-phase vertical pneumatic transport of solids, referred to in the literature as circulating fluidized beds, computed using a generalization of the Navier-Stokes equations for two fluids. In the less dense regime corresponding to volume fractions of solids of about 1%, the flow consists of centrally upward moving solids and downward moving clusters. The

Yuan P. Tsuo; D. Gidaspow

1990-01-01

456

Novel multiscale simulation environment for modeling of fluidized bed granulation  

NASA Astrophysics Data System (ADS)

In this contribution the architecture of a novel simulation environment, which has been developedfor the multiscale modeling of fluidized bed spray granulation, is presented. The novel environment describes the granulation process on four different time and length scales. On the one hand, it allows to predict dynamics of the global production process, whereby, on the other hand, material properties can be considered.

Dosta, Maksym; Heinrich, Stefan

2013-06-01

457

Lagrangian Approach to Study Catalytic Fluidized Bed Reactors  

NASA Astrophysics Data System (ADS)

Lagrangian approach of fluidized bed reactors is a method, which simulates the movement of catalyst particles (caused by the fluidization) by changing the gas composition around them. Application of such an investigation is in the analysis of the state of catalysts and surface reactions under quasi-operando conditions. The hydrodynamics of catalyst particles within a fluidized bed reactor was studied to improve a Lagrangian approach. A fluidized bed methanation employed in the production of Synthetic Natural Gas from wood was chosen as the case study. The Lagrangian perspective was modified and improved to include different particle circulation patterns, which were investigated through this study. Experiments were designed to evaluate the concepts of the model. The results indicate that the setup is able to perform the designed experiments and a good agreement between the simulation and the experimental results were observed. It has been shown that fluidized bed reactors, as opposed to fixed beds, can be used to avoid the deactivation of the methanation catalyst due to carbon deposits. Carbon deposition on the catalysts tested with the Lagrangian approach was investigated by temperature programmed oxidation (TPO) analysis of ex-situ catalyst samples. This investigation was done to identify the effects of particles velocity and their circulation patterns on the amount and type of deposited carbon on the catalyst surface.

Madi, Hossein

2013-03-01

458

JPL in-house fluidized bed reactor research  

NASA Technical Reports Server (NTRS)

The progress in the in-house program on the silane fluidized-bed system is reported. A seed-particle cleaning procedure was developed to obtain material purity near the level required to produce a semiconductor-grade product. The liner-seal design was consistently proven to withstand heating/cooling cycles in all of the experimental runs.

Rohatgi, N. K.

1985-01-01

459

JPL in-house fluidized-bed reactor research  

NASA Technical Reports Server (NTRS)

Data is given on metallic impurities in fluidized bed reactors (FBR). Various wall materials for FBR's are characterized. Reaction paths for FBR's and conditions for the incorporation of homogenous fines onto seed particles are discussed. Scavenging experiment data and jet mill grinding data are given.

Hsu, G. C.

1984-01-01

460

Design and Application of Novel Horizontal Circulating Fluidized Bed Boiler  

Microsoft Academic Search

The vertical circulating fluidized bed (CFB) boiler has been found wide application in power generation and tends to be enlarged in capacity. Because CFB is one of environment friendly and high efficiency combustion technologies, the CFB boiler has also been expected to be used in the industrial area, such as textile mill, region heating, brewery, seed drying and so on.

Q. H. Lit; Y. G. Zhang; A. H. Meng

2010-01-01

461

Pressure Fluctuations as a Diagnostic Tool for Fluidized Beds.  

National Technical Information Service (NTIS)

The validity of using bubbling fluidized bed (BFB) similitude parameters to match a hot BFB to a cold BFB is being studied. Sand in a BFB combustor and copper powder in cold BFB model have been analyzed and found to be out of similitude. In the analysis p...

R. C. Brown J. R. Schroeder

1997-01-01

462

Pyrolysis of Softwood Carbohydrates in a Fluidized Bed Reactor  

Microsoft Academic Search

In the present work pyrolysis of pure pine wood and softwood carbohydrates, namely cellulose and galactoglucomannan (the major hemicellulose in coniferous wood), was conducted in a batch mode operated fluidized bed reactor. Temperature ramping (5 °C\\/min) was applied to the heating until a reactor temperature of 460 °C was reached. Thereafter the temperature was kept until the release of non-condensable

Atte Aho; Narendra Kumar; Kari Eränen; Bjarne Holmbom; Mikko Hupa; Tapio Salmi; Dmitry Yu. Murzin

2008-01-01

463

Mechanism of Mechanical Activation of Circulating Fluidized Bed Fly Ash  

Microsoft Academic Search

Circulating fluidized bed (CFB) fly ash with high loss on ignition is hard to utilize, which become a hindrance for promoting the CFB power plant. In the paper, cementitious activity of the fly ash is improved by milling it. And the effects of mechano-chemistry and carbon structure on its activity during grinding process were studied by XRD, SEM and FTIR

Li Jing-Tao; Lei Xiu-Jian; Zhang Wen-Qing; Zhao Yong-Hong

2010-01-01

464

In silico modeling of in situ fluidized bed melt granulation.  

PubMed

Fluidized bed melt granulation has recently been recognized as a promising technique with numerous advantages over conventional granulation techniques. The aim of this study was to evaluate the possibility of using response surface methodology and artificial neural networks for optimizing in situ fluidized bed melt granulation and to compare them with regard to modeling ability and predictability. The experiments were organized in line with the Box-Behnken design. The influence of binder content, binder particle size, and granulation time on granule properties was evaluated. In addition to the response surface analysis, a multilayer perceptron neural network was applied for data modeling. It was found that in situ fluidized bed melt granulation can be used for production of spherical granules with good flowability. Binder particle size had the most pronounced influence on granule size and shape, suggesting the importance of this parameter in achieving desired granule properties. It was found that binder content can be a critical factor for the width of granule size distribution and yield when immersion and layering is the dominant agglomeration mechanism. The results obtained indicate that both in silico techniques can be useful tools in defining the design space and optimization of in situ fluidized bed melt granulation. PMID:24607215

Aleksi?, Ivana; Duriš, Jelena; Ili?, Ilija; Ibri?, Svetlana; Paroj?i?, Jelena; Sr?i?, Stanko

2014-05-15

465

Experimental evaluation and modeling of agglomerating fine powder fluidized beds  

Microsoft Academic Search

The effects of fines on the behavior of a fluidized-bed reactor have been investigated using a commercial catalyst for propylene ammoxidation. Experimental studies show that the catalyst powder agglomerates and that there exists a critical level of fines in the bed (around 30%) for which the fluid-bed behavior in terms of bed expansion, aeratability, and cluster size is optimum. The

N. K. Yadav; B. D. Kulkarni; L. K. Doraiswamy

1994-01-01

466

Numerical analysis of particle mixing in a rotating fluidized bed  

Microsoft Academic Search

This paper describes the numerical analysis of particle mixing in a rotating fluidized bed (RFB). A two-dimensional discrete element method (DEM) and computational fluid dynamics (CFD) coupling model were proposed to analyze the radial particle mixing in the RFB. Spherical polyethylene particles (Geldart group B particles) were used as model particles under the assumptions that they were cohesionless and mono-disperse

Hideya Nakamura; Takayuki Tokuda; Tomohiro Iwasaki; Satoru Watano

2007-01-01

467

CFD simulations of particle mixing in a binary fluidized bed  

Microsoft Academic Search

It has long been known that fluidization of dissimilar materials can result in either a well-mixed bed or a segregated bed. In a fluidized bed, particle mixing and segregation phenomena are dominated by bubble activity. Depending on operating conditions, lighter or smaller particles (“flotsam”) tend to rise to the bed, and larger, heavier particles (“jetsam”) tend to sink to the

Scott Cooper; Charles J. Coronella

2005-01-01

468

Fluidized bed biodenitrification of gaseous diffusion plant aqueous wastes  

SciTech Connect

Decontamination and uranium recovery operations at the Portsmouth Gaseous Diffusion Plant generate nitrate containing raffinates. A biodenitrification process will be used to meet more stringent EPA nitrate emission constraints soon in effect. Fluidized bed reactor studies at ORNL provided data necessary to characterize bioreactor performance and generate design criteria. 11 refs., 4 figs., 5 tabs.

Kowalchuk, M.L.; Hancher, C.W.

1982-10-24

469

Low-Pressure-Drop Fluidized-Bed Distributor.  

National Technical Information Service (NTIS)

The compressor power required to maintain fluidization is one of the high cost factors in the application of fluidized bed combustors. Good uniform fluidization can be obtained if the distributor air injector tubes are so small that they cause a pressure ...

J. L. Loth B. Mansouri

1980-01-01

470

Charging of glass powder in a circulating fluidized bed  

Microsoft Academic Search

A laboratory scale circulating fluidized bed of 2.54 cm internal diameter was experimentally studied for the triboelectric charging of glass powder. Both copper and Plexiglas bed risers were investigated. The particle charge was measured by a sampling probe Faraday cage positioned at the exit of the freeboard with a second Faraday cage used to sample particles from the bottom of

D. Tucholski; G. M. Colver

1998-01-01

471

Advances in liquid fluidized-bed heat exchanger development  

Microsoft Academic Search

The paper reports the first heat transfer results from a horizontal liquid fluidized-bed heat exchanger. Geothermal water from Raft River Geothermal Wells provided the heat source. Treated water was the secondary fluid. Silica sand closely screened to 16 mesh was the bed material. The exchanger was 8 in. in diameter by 15 in. long. Heat transfer results are compared with

E. S. Grimmett; A. F. Fanous; C. A. Allen

1977-01-01

472

Direct indication of particle size in fluidized beds  

NASA Technical Reports Server (NTRS)

Differential pressure measurements indicate particle size and particle size distribution in fluidized beds. The technique is based on the relationship between bed particle size and the intensity and frequency of fluctuations. By measuring the fluctuations, an estimate of average particle size of the fluid-bed material can be made.

Knudsen, I. E.; Olsen, W. F.

1969-01-01

473

Measurement of solids motion in gas-fluidized beds  

NASA Astrophysics Data System (ADS)

The research concerns the measurement of solid particle velocity distribution and residence time distribution using a computer aided radioactive particle tracing technique. Microspheres were machined from a scandium rod and coated with polyester urethane. The design of the 1 m fluidized bed is nearly complete.

Chen, M. M.; Chao, B. T.

474

Evaluation of fluidized-bed methanation catalysts and reactor modeling  

Microsoft Academic Search

The simple reactor model developed for the fluidized-bed methanator PEDU gives reasonably good parity plots for six PEDU tests using six different catalysts. This model can be used to predict the performance of the pilot plant methanator and as a building block in any computerized simulation of the BI-GAS process for process development, design or optimization purposes. Some refinements could

James T. Cobb; Robert C. Streeter

1979-01-01

475

TREATMENT OF MUNICIPAL WASTEWATERS BY THE FLUIDIZED BED BIOREACTOR PROCESS  

EPA Science Inventory

A 2-year, large-scale pilot investigation was conducted at the City of Newburgh Water Pollution Control Plant, Newburgh, NY, to demonstrate the application of the fluidized bed bioreactor process to the treatment of municipal wastewaters. The experimental effort investigated the ...

476

Phase shift method to estimate solids circulation rate in circulating fluidized beds  

SciTech Connect

While solids circulation rate is a critical design and control parameter in circulating fluidized bed (CFB) reactor systems, there are no available techniques to measure it directly at conditions of industrial interest. Cold flow tests have been conducted at NETL in an industrial scale CFB unit where the solids flow has been the topic of research in order to develop an independent method which could be applied to CFBs operating under the erosive and corrosive high temperatures and pressures of a coal fired boiler or gasifier. The dynamic responses of the CFB loop to modest modulated aeration flows in the return leg or standpipe were imposed to establish a periodic response in the unit without causing upset in the process performance. The resulting periodic behavior could then be analyzed with a dynamic model and the average solids circulation rate could be established. This method was applied to the CFB unit operated under a wide range of operating conditions including fast fluidization, core annular flow, dilute and dense transport, and dense suspension upflow. In addition, the system was operated in both low and high total solids inventories to explore the influence of inventory limiting cases on the estimated results. The technique was able to estimate the solids circulation rate for all transport circulating fluidized beds when operating above upper transport velocity, U{sub tr2}. For CFB operating in the fast fluidized bed regime (i.e., U{sub g}< U{sub tr2}), the phase shift technique was not successful. The riser pressure drop becomes independent of the solids circulation rate and the mass flow rate out of the riser does not show modulated behavior even when the riser pressure drop does.

Ludlow, James Christopher [U.S. DOE (retired); Panday, Rupen [REM; Shadle, Lawrence J. [U.S. DOE

2013-01-01

477

Mathematical model for the continuous combustion of char particles in a fluidized bed  

SciTech Connect

Recently, we have developed the direct oxidation model for the combustion of a batch of char in a fluidized bed. This analysis is extended for the continuous combustion of char, and a system of general equations has been derived to relate the feed rate of char to the amount of char particles present in the fluidized bed and in the overflow stream. The size distribution of char particles and their number in the bed are also predicted. The analysis indicates that the amount of carbon present in the bed is independent of the feed particle size at fixed values of the char feed rate and fluidizing-gas velocity although the number of char bed particles depends upon the feed particle size. Further, the carbon content of the bed and the number of char particles in the bed are found to depend heavily on the char feed rate and the fluidizing-gas velocity. A discrete cut method is described whereby the particle size distribution and the number of particles present in the bed are calculated. The method provides a simplified trial-and-error procedure for those cases in which the rate of change in particle size is a complex nonintegrable function of the particle size. The discrete cut method is found to yield results which are in good agreement with the exact solutions of the integrals defining the number of particles and their size distribution. The model provides a simple base for the scale-up and design work related to fluidized-bed coal combustors.

Saxena, S.C.; Rehmat, A.

1980-12-01

478

Development of methods to predict agglomeration and deposition in fluidized-bed combustion systems (FBCS). Topical report  

SciTech Connect

The successful design and operation of advanced combustion systems require the ability to control and mitigate ash-related problems. The major ash-related problems are slag flow control, slag attack on the refractory, ash deposition on heat-transfer surfaces, corrosion and erosion of equipment materials, and emissions control. These problems are the result of physical and chemical interactions of the fuels, bed materials, and system components. The interactions that take place and ultimately control ash behavior in fluidized-bed combustion (FBC) systems are controlled by the abundance and association of the inorganic components in coal and by the system conditions. Because of the complexity of the materials and processes involved, the design and operations engineer often lacks the information needed to predict ash behavior and reduce ash-related problems. The deposition of ashes from the fl