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Sample records for bed combustion cfbc

  1. Low-reactive circulating fluidized bed combustion (CFBC) fly ashes as source material for geopolymer synthesis.

    PubMed

    Xu, Hui; Li, Qin; Shen, Lifeng; Zhang, Mengqun; Zhai, Jianping

    2010-01-01

    In this contribution, low-reactive circulating fluidized bed combustion (CFBC) fly ashes (CFAs) have firstly been utilized as a source material for geopolymer synthesis. An alkali fusion process was employed to promote the dissolution of Si and Al species from the CFAs, and thus to enhance the reactivity of the ashes. A high-reactive metakaolin (MK) was also used to consume the excess alkali needed for the fusion. Reactivities of the CFAs and MK were examined by a series of dissolution tests in sodium hydroxide solutions. Geopolymer samples were prepared by alkali activation of the source materials using a sodium silicate solution as the activator. The synthesized products were characterized by mechanical testing, scanning electron microscopy (SEM), X-ray diffractography (XRD), as well as Fourier transform infrared spectroscopy (FTIR). The results of this study indicate that, via enhancing the reactivity by alkali fusion and balancing the Na/Al ratio by additional aluminosilicate source, low-reactive CFAs could also be recycled as an alternative source material for geopolymer production. PMID:19853434

  2. Synthesis of thermostable geopolymer from circulating fluidized bed combustion (CFBC) bottom ashes.

    PubMed

    Xu, Hui; Li, Qin; Shen, Lifeng; Wang, Wei; Zhai, Jianping

    2010-03-15

    Circulating fluidized bed combustion (CFBC) bottom ashes (CBAs) are a class of calcined aluminosilicate wastes with a unique thermal history. While landfill disposal of hazardous element-containing CBAs poses serious challenge, these wastes have long been neglected as source materials for geopolymer production. In this paper, geopolymerization of ground CBAs was investigated. Reactivity of the CBAs was analyzed by respective dissolution of the ashes in 2, 5, and 10N NaOH and KOH solutions. Geopolymer pastes were prepared by activating the CBAs by a series of alkalis hydroxides and/or sodium silicate solutions. Samples were cured at 40 degrees C for 168 h, giving a highest compressive strength of 52.9 MPa. Of the optimal specimen, characterization was conducted by TG-DTA, SEM, XRD, as well as FTIR analyses, and thermal stability was determined in terms of compressive strength evolution via exposure to 800 or 1050 degrees C followed by three cooling regimes, i.e. cooling in air, cooling in the furnace, and immerging in water. The results show that CBAs could serve as favorable source materials for thermostable geopolymers, which hold a promise to replace ordinary Portland cement (OPC) and organic polymers in a variety of applications, especially where fire hazards are of great concern. PMID:19879690

  3. Low-reactive circulating fluidized bed combustion (CFBC) fly ashes as source material for geopolymer synthesis

    SciTech Connect

    Xu Hui; Li Qin; Shen Lifeng; Zhang Mengqun; Zhai Jianping

    2010-01-15

    In this contribution, low-reactive circulating fluidized bed combustion (CFBC) fly ashes (CFAs) have firstly been utilized as a source material for geopolymer synthesis. An alkali fusion process was employed to promote the dissolution of Si and Al species from the CFAs, and thus to enhance the reactivity of the ashes. A high-reactive metakaolin (MK) was also used to consume the excess alkali needed for the fusion. Reactivities of the CFAs and MK were examined by a series of dissolution tests in sodium hydroxide solutions. Geopolymer samples were prepared by alkali activation of the source materials using a sodium silicate solution as the activator. The synthesized products were characterized by mechanical testing, scanning electron microscopy (SEM), X-ray diffractography (XRD), as well as Fourier transform infrared spectroscopy (FTIR). The results of this study indicate that, via enhancing the reactivity by alkali fusion and balancing the Na/Al ratio by additional aluminosilicate source, low-reactive CFAs could also be recycled as an alternative source material for geopolymer production.

  4. 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 ...

  5. Experimental study of oxy-fuel combustion and sulfur capture in a mini-CFBC

    SciTech Connect

    L. Jia; Y. Tan; C. Wang; E.J. Anthony

    2007-12-15

    Oxy-fuel technology uses effectively pure oxygen for fossil fuel combustion in order to obtain a highly concentrated CO{sub 2} stream, suitable for direct compression and sequestration. It is an effective technology to reduce greenhouse gas emissions to the atmosphere from large point sources such as power generation plants. Oxy-fuel FBC technology has the combined advantage of producing high CO{sub 2} concentration flue gas and allowing excellent fuel flexibility. In addition, with external cooling of the recirculated solids, the flue gas recirculation ratio can be reduced. CETC-Ottawa has carried out oxy-fuel fluidized bed combustion with flue gas recirculation on its modified mini-CFBC. The mini-CFBC has an internal diameter of 100 mm and internal height of 5000 mm. Both bituminous and sub-bituminous coals were fired. Limestone was premixed with coal and fed to the mini-CFBC. Recirculated solids were cooled in the return leg of the mini-CFBC. The bed temperature was controlled at about 850{sup o}C, while the oxygen concentration in the primary gas was about 25% and in the secondary gas was about 50%. With flue gas recycle, the CO{sub 2} concentration in the flue gas reached 82-90%. Sulfur capture efficiency and CO and NOx concentrations were also measured and were all at acceptable levels. The transition from air firing to oxy-fuel firing was a fast and relatively smooth process, and operation of the mini-CFBC under oxy-fuel firing conditions was similar to that of air firing. 15 refs., 4 figs., 3 tabs.

  6. Combustion Of Poultry-Derived Fuel in a CFBC

    NASA Astrophysics Data System (ADS)

    Jia, Lufei; Anthony, Edward J.

    Poultry farming generates large quantities of waste. Current disposal practice is to spread the poultry wastes onto farmland as fertilizer. However, as the factory farms for poultry grow both in numbers and size, the amount of poultry wastes generated has increased significandy in recent years. In consequence, excessive application of poultry wastes on farmland is resulting in more and more contaminants entering the surface water. One of the options being considered is the use of poultry waste as power plant fuel. Since poultry-derived fuel (PDF) is biomass, its co-firing will have the added advantage of reducing greenhouse gas emissions from power generation. To evaluate the combustion characteristics of co-firing PDF with coal, combustion tests of mixtures of coal and PDF were conducted in CanmetENERGY's pilot-scale CFBC. The goal of the tests was to verify that PDF can be co-fired with coal and, more importantly, that emissions from the combustion process are not adversely affected by the presence of PDF in the fuel feed. The test results were very promising and support the view that co-firing in an existing coal-fired CFBC is an effective method of utilizing this potential fuel, both resolving a potential waste disposal problem and reducing the amount of CO2 released by the boiler.

  7. Pulsed atmospheric fluidized bed combustion

    SciTech Connect

    Not Available

    1989-11-01

    In order to verify the technical feasibility of the MTCI Pulsed Atmospheric Fluidized Bed Combustor technology, a laboratory-scale system was designed, built and tested. Important aspects of the operational and performance parameters of the system were established experimentally. A considerable amount of the effort was invested in the initial task of constructing an AFBC that would represent a reasonable baseline against which the performance of the PAFBC could be compared. A summary comparison of the performance and emissions data from the MTCI 2 ft {times} 2 ft facility (AFBC and PAFBC modes) with those from conventional BFBC (taller freeboard and recycle operation) and circulating fluidized bed combustion (CFBC) units is given in Table ES-1. The comparison is for typical high-volatile bituminous coals and sorbents of average reactivity. The values indicated for BFBC and CFBC were based on published information. The AFBC unit that was designed to act as a baseline for the comparison was indeed representative of the larger units even at the smaller scale for which it was designed. The PAFBC mode exhibited superior performance in relation to the AFBC mode. The higher combustion efficiency translates into reduced coal consumption and lower system operating cost; the improvement in sulfur capture implies less sorbent requirement and waste generation and in turn lower operating cost; lower NO{sub x} and CO emissions mean ease of site permitting; and greater steam-generation rate translates into less heat exchange surface area and reduced capital cost. Also, the PAFBC performance generally surpasses those of conventional BFBC, is comparable to CFBC in combustion and NO{sub x} emissions, and is better than CFBC in sulfur capture and CO emissions even at the scaled-down size used for the experimental feasibility tests.

  8. Pulsed atmospheric fluidized bed combustion. Final report

    SciTech Connect

    Not Available

    1989-11-01

    In order to verify the technical feasibility of the MTCI Pulsed Atmospheric Fluidized Bed Combustor technology, a laboratory-scale system was designed, built and tested. Important aspects of the operational and performance parameters of the system were established experimentally. A considerable amount of the effort was invested in the initial task of constructing an AFBC that would represent a reasonable baseline against which the performance of the PAFBC could be compared. A summary comparison of the performance and emissions data from the MTCI 2 ft {times} 2 ft facility (AFBC and PAFBC modes) with those from conventional BFBC (taller freeboard and recycle operation) and circulating fluidized bed combustion (CFBC) units is given in Table ES-1. The comparison is for typical high-volatile bituminous coals and sorbents of average reactivity. The values indicated for BFBC and CFBC were based on published information. The AFBC unit that was designed to act as a baseline for the comparison was indeed representative of the larger units even at the smaller scale for which it was designed. The PAFBC mode exhibited superior performance in relation to the AFBC mode. The higher combustion efficiency translates into reduced coal consumption and lower system operating cost; the improvement in sulfur capture implies less sorbent requirement and waste generation and in turn lower operating cost; lower NO{sub x} and CO emissions mean ease of site permitting; and greater steam-generation rate translates into less heat exchange surface area and reduced capital cost. Also, the PAFBC performance generally surpasses those of conventional BFBC, is comparable to CFBC in combustion and NO{sub x} emissions, and is better than CFBC in sulfur capture and CO emissions even at the scaled-down size used for the experimental feasibility tests.

  9. ESTABLISHMENT OF AN ENVIRONMENTAL CONTROL TECHNOLOGY LABORATORY WITH A CIRCULATING FLUIDIZED-BED COMBUSTION SYSTEM

    SciTech Connect

    Wei-Ping Pan; Kunlei Liu; John T. Riley

    2004-01-01

    The purpose of this report is to summarize the progress made on the project ''Establishment of an Environmental Control Technology Laboratory with a Circulating Fluidized-Bed Combustion (CFBC) System'' in this quarter (September-December of 2003). The main tasks in this quarter consisted of the following four parts. First, all documents for managing this project have been prepared and sent to the Office of Project Management at the US Department of Energy's (DOE's) National Energy Technology Laboratory (NETL). Second, plans for the renovation of space for a new combustion laboratory for the CFBC system has progressed smoothly. Third, considerable progress in the design of the CFBC system has been made. Finally, a lab-scale simulated fluidized-bed combustion facility has been set up in order to make some fundamental investigations of the co-firing of coal with waste materials in the next quarter. Proposed work for the next quarter has been outlined in this report.

  10. Fluidized bed combustion

    SciTech Connect

    Sowards, N.K.; Murphy, M.L.

    1992-04-07

    This patent describes a method of incinerating a fuel containing difficult to remove tramp comprising wire. It comprises placing of a fluid bed within a downwardly and inwardly tapered centrally hollow air distributor disposed within a lower portion of a vessel; introducing fuel comprising combustible material and tramp comprising wire into the fluid bed; incinerating the combustible material in the fluid bed accommodating downward migration within the fluid bed of the wire without a central obstruction to such migration; in the course of performing the incinerating step, fluidizing the bed solely by introducing inwardly at several tiered locations directed air into the bed only around the tapered periphery along the lower portion of the vessel from a plurality of inwardly and downwardly parallel sites as causing the bed material and tramp to migrate downwardly and inwardly without central bed obstruction toward a discharge site.

  11. Hybrid fluidized bed combuster

    DOEpatents

    Kantesaria, Prabhudas P.; Matthews, Francis T.

    1982-01-01

    A first atmospheric bubbling fluidized bed furnace is combined with a second turbulent, circulating fluidized bed furnace to produce heat efficiently from crushed solid fuel. The bed of the second furnace receives the smaller sizes of crushed solid fuel, unreacted limestone from the first bed, and elutriated solids extracted from the flu gases of the first bed. The two-stage combustion of crushed solid fuel provides a system with an efficiency greater than available with use of a single furnace of a fluidized bed.

  12. ESTABLISHMENT OF AN ENVIRONMENTAL CONTROL TECHNOLOGY LABORATORY WITH A CIRCULATING FLUIDIZED-BED COMBUSTION SYSTEM

    SciTech Connect

    Wei-Ping Pan; Andy Wu; John T. Riley

    2005-07-30

    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.

  13. Establishment of an Environmental Control Technology Laboratory with a Circulating Fluidized-Bed Combustion System

    SciTech Connect

    Wei-Ping Pan; Yan Cao; John Smith

    2006-07-01

    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, 2006 through June 30, 2006. Substantial progress was made on the development and application of software for the effective operation and safe control of the Circulating Fluidized-Bed (CFB) Combustor, as well as for the display and logging of acquired data and operating parameters.

  14. Establishment of an Environmental Control Technology Laboratory with a Circulating Fluidized-Bed Combustion System

    SciTech Connect

    Wei-Ping Pan; Songgeng Li

    2006-01-01

    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 October 1, 2005 through December 31, 2005. Work was performed on the following activities. First, the fabrication and manufacture of the CFBC Facility is nearly completed. The erection of the CFBC facility is expected to start in the second week of February, 2006. Second, effect of flue gas components on mercury oxidation was investigated in a drop tube reactor. As a first step, experiment for mercury oxidation by chlorine was investigated. The experimental results from this study are presented in this report. Finally, the proposed work for the next quarter is described in this report.

  15. ESTABLISHMENT OF AN ENVIRONMENTAL CONTROL TECHNOLOGY LABORATORY WITH A CIRCULATING FLUIDIZED-BED COMBUSTION SYSTEM

    SciTech Connect

    Wei-Ping Pan; Andy Wu; John T. Riley

    2004-10-30

    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 July 1, 2004 through September 30, 2004. The following tasks have been completed. First, renovation of the new Combustion Laboratory and the construction of the Circulating Fluidized-Bed (CFB) Combustor Building have started. Second, the design if the component parts of the CFBC system have been reviewed and finalized so that the drawings may be released to the manufacturers during the next quarter. Third, the experiments for solid waste (chicken litter) incineration have been conducted using a Thermogravimetric Analyzer (TGA). This is in preparation for testing in the simulated fluidized-bed combustor. The experimental results from this study are presented in this report. Finally, the proposed work for the next quarter has been outlined in this report.

  16. ESTABLISHMENT OF AN ENVIRONMENTAL CONTROL TECHNOLOGY LABORATORY WITH A CIRCULATING FLUIDIZED-BED COMBUSTION SYSTEM

    SciTech Connect

    Wei-Ping Pan; Andy Wu; John T. Riley

    2005-01-30

    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 October 1, 2004 through December 31, 2004. The following tasks have been completed. First, the renovation of the new Combustion Laboratory and the construction of the Circulating Fluidized-Bed (CFB) Combustor Building have proceeded well. Second, the detailed design of supporting and hanging structures for the CFBC was completed. Third, the laboratory-scale simulated fluidized-bed facility was modified after completing a series of pretests. The two problems identified during the pretest were solved. Fourth, the carbonization of chicken waste and coal was investigated in a tube furnace and a Thermogravimetric Analyzer (TGA). The experimental results from this study are presented in this report. Finally, the proposed work for the next quarter has been outlined in this report.

  17. Combustion in fluidized beds

    SciTech Connect

    Dry, F.J.; La Nauze, R.D. )

    1990-07-01

    Circulating fluidized-bed (CFB) combustion systems have become popular since the late 1970s, and, given the current level of activity in the area,it is clear that this technology has a stable future in the boiler market. For standard coal combustion applications, competition is fierce with mature pulverized-fuel-based (PF) technology set to maintain a strong profile. CFB systems, however, can be more cost effective than PF systems when emission control is considered, and, as CFB technology matures, it is expected that an ever-increasing proportion of boiler installations will utilize the CFB concept. CFB systems have advantages in the combustion of low-grade fuels such as coal waste and biomass. In competition with conventional bubbling beds, the CFB boiler often demonstrates superior carbon burn-out efficiency. The key to this combustion technique is the hydrodynamic behavior of the fluidized bed. This article begins with a description of the fundamental fluid dynamic behavior of the CFB system. This is followed by an examination of the combustion process in such an environment and a discussion of the current status of the major CFB technologies.

  18. Fluidized-bed combustion

    SciTech Connect

    Botros, P E

    1990-04-01

    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.

  19. Establishment of an Environmental Control Technology Laboratory with a Circulating Fluidized-Bed Combustion System

    SciTech Connect

    Wei-Ping Pan; Yan Cao; Songgeng Li

    2006-04-01

    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, 2006 through March 31, 2006. Work was performed on the following activities. First, the fabrication and manufacture of the CFBC Facility were completed. The riser, primary cyclone and secondary cyclone of Circulating Fluidized Bed (CFB) Combustor have been erected. Second, the Mercury Control Workshop and the Grand Opening of Institute for Combustion Science and Environmental Technology (ICSET) were successfully held on February 22 and 23, 2006, respectively. Third, effects of hydrogen chlorine (HCl) and sulfur dioxide (SO{sub 2}) on mercury oxidation were studied in a drop tube reactor. The experimental results from this study are presented in this report. Finally, the proposed work for the next quarter is described in this report.

  20. Review of fluidized bed combustion technology in the United States

    SciTech Connect

    Krishnan, R.P.; Daw, C.S.; Jones, J.E. Jr.

    1984-01-01

    The United States (US) initiated work in fluidized bed combustion (FBC) in the mid-1960s, with primary emphasis on industrial applications. With passage of the Clean Air Act in 1970, the environmental benefits of the technology soon attracted interest. This provided the impetus for expanded effort focused on the reduced NO/sub x/ emissions resulting from lower combustion temperature and SO/sub 2/ capture by means of chemical reaction with limestone or dolomite in the fluidized bed. The oil embargo in 1973 further stimulated interest in FBC technology. Several manufacturers presently offer atmospheric fluidized bed combustion (AFBC) and circulating fluidized bed combustion (CFBC) units for industrial application in the United States. However, FBC for electric power generation remains in the development and demonstration phase. The Tennessee Valley Authority (TVA) and Electric Power Research Institute (EPRI) are operating a 20-MW AFBC utility pilot plant and are proceeding with plans for a 160-MW(e) demonstration plant with other participants. Research has been under way on pressurized fluidized bed combustion (PFBC) at Grimethorpe in South Yorkshire, England, and within the United States at the Curtiss-Wright Pilot Plant, and at other smaller test facilities. An emerging turbocharged PFBC concept will likely stimulate more near-term interest in PFBC technology for both industrial and utility applications. The major US programs and test facilities are described; remaining technical uncertainties are discussed, and the future outlook for the technology is assessed.

  1. Desulfurization with a modified limestone formulation in an industrial CFBC boiler

    SciTech Connect

    Young Goo Park; Seung Ho Kim

    2006-02-01

    This work presents a practical result of experimental investigation of the limestone particle size effect on de-SOx from a circulating fluidized bed combustion (CFBC) boiler that burns domestic anthracite and is the first industrial scale in Korea. Because of combustion problems such as clinker formation, fine limestone has not been used as a desulfurization agent. The present test, however, showed that higher content (up to 50%) of the particles under 0.1 mm did not entail any malfunction in a modern CFBC system. In addition, the desulfurization efficiency was found to be comparable to the old mode of limestone sorbents. 17 refs., 4 figs., 3 tabs.

  2. Establishment of an Environmental Control Technology Laboratory with a Circulating Fluidized-Bed Combustion System

    SciTech Connect

    Wei-Ping Pan; Zhongxian Cheng; Yan Cao; John Smith

    2006-09-30

    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 July 1, 2006 through September 30, 2006. The following activities have been completed: the steel floor grating around the riser in all levels and the three-phase power supply for CFBC System was installed. Erection of downcomers, loop seals, ash bunker, thermal expansion joints, fuel and bed material bunkers with load cells, rotary air-lock valves and fuel flow monitors is underway. Pilot-scale slipstream tests conducted with bromine compound addition were performed for two typical types of coal. The purposes of the tests were to study the effect of bromine addition on mercury oxidization. From the test results, it was observed that there was a strong oxidization effect for Powder River Basin (PRB) coal. The proposed work for next quarter and project schedule are also described.

  3. ESTABLISHMENT OF AN ENVIRONMENTAL CONTROL TECHNOLOGY LABORATORY WITH A CIRCULATING FLUIDIZED-BED COMBUSTION SYSTEM

    SciTech Connect

    Wei-Ping Pan, Kunlei Liu; John T. Riley

    2004-07-30

    This report presents the progress made on the project ''Establishment of an Environmental Control Technology Laboratory (ECTL) with a Circulating Fluidized-Bed Combustion (CFBC) System'' during the quarter April 1--June 30, 2004. The following tasks have been completed. First, the final specifications for the renovation of the new Combustion Laboratory and the construction of the CFB Combustor Building have been delivered to the architect, and invitations for construction bids for the two tasks have been released. Second, the component parts of the CFBC system have been designed after the design work for assembly parts of the CFBC system was completed. Third, the literature pertaining to Polychlorinated Dibenzo-p-Dioxins (PCDD) and Polychlorinated Dibenzofurans (PCDF) released during the incineration of solid waste, including municipal solid waste (MSW) and refuse-derived fuel (RDF) have been reviewed, and an experimental plan for fundamental research of MSW incineration on a simulated fluidized-bed combustion (FBC) facility has been prepared. Finally, the proposed work for the next quarter has been outlined in this report.

  4. ESTABLISHMENT OF AN ENVIRONMENTAL CONTROL TECHNOLOGY LABORATORY WITH A CIRCULATING FLUIDIZED-BED COMBUSTION SYSTEM

    SciTech Connect

    Wei-Ping Pan; Andy Wu; John T. Riley

    2005-04-30

    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.

  5. Advanced ash management technologies for CFBC ash.

    PubMed

    Anthony, E J; Berry, E E; Blondin, J; Bulewicz, E M; Burwell, S

    2003-01-01

    The combustion of high-sulphur coal demands the reduction of sulphur emissions. The sorbent most often used in sulphur capture technology is calcium-based. Ashes from technologies such as circulating fluidized bed combustion (CFBC), therefore, contain high calcium levels. The use and disposal of these ashes poses challenges, because of highly exothermic reactions with water, high-pH leachates, and excessive expansion of solidified materials. This paper looks at the potential of two post-combustion ash treatment processes, CERCHAR hydration and AWDS disposal, in solving these challenges. A high-sulphur coal-derived CFBC ash is examined, after CERCHAR hydration treatment, in conjunction with a conventionally hydrated ash, in a range of chemical, geotechnical and utilization scenarios. The ashes are used to make no-cement and roller-compacted concrete as well as Ash Water Dense Suspensions (AWDS). The solidified mortar paste from no-cement concrete is subjected to an extensive geochemical examination to determine how solidification progresses and strength develops, from a chemical point of view. PMID:12909091

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

    SciTech Connect

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

    2007-08-15

    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. The coal is high in moisture, ash, and sulfur and has a low heating value. Both the moisture and the sulfur proved problematic for the CTF tests. The fuel had to be dried to less than 37% moisture before it could be pulverized and further dried to about 25% moisture to allow more uniform feeding into the combustor. During some tests, water was injected into the furnace to simulate the level of flue gas moisture had the fuel been fed without drying. A spray dryer was used downstream of the baghouse to remove sufficient sulfur to meet the EERC emission standards permitted by the North Dakota Department of Health. In addition to a test matrix varying excess air, burner swirl, and load, two longer-term tests were performed to evaluate the fouling potential of the coal at two different temperatures. At the lower temperature (1051 C), very little ash was deposited on the probes, but deposition did occur on the walls upstream of the probe bank, forcing an early end to the test after 2 hours and 40 minutes of testing. At the higher temperature (1116 C), ash deposition on the probes was significant, resulting in termination of the test after only 40 minutes. The same coal was burned in the CFBC, but because the CFBC uses a larger size of material, it was able to feed this coal at a higher moisture content (average of 40.1%) compared to the CTF (ranging from 24.2% to 26.9%). Sulfur control was achieved with the addition of limestone to the bed, although the high calcium-to-sulfur rate required to reduce SO{sub 2} emissions resulted in heat loss (through limestone calcination) and additional ash

  7. Establishment of an Environmental Control Technology Laboratory with a Circulating Fluidized-Bed Combustion System

    SciTech Connect

    Wei-Ping Pan; Yan Cao; John Smith

    2008-05-31

    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

  8. Establishment of an Environmental Control Technology Laboratory with a Circulating Fluidized-Bed Combustion System

    SciTech Connect

    Wei-Ping Pan; Yan Cao; John Smith

    2007-03-31

    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.

  9. Bed material agglomeration during fluidized bed combustion

    SciTech Connect

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

    1993-02-01

    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.

  10. ESTABLISHMENT OF AN ENVIRONMENTAL CONTROL TECHNOLOGY LABORATORY WITH A CIRCULATING FLUIDIZED-BED COMBUSTION SYSTEM

    SciTech Connect

    Wei-Ping Pan; Kunlei Liu; John T. Riley

    2004-04-01

    The purpose of this report is to present the progress made on the project ''Establishment of an Environmental Control Technology Laboratory with a Circulating Fluidized-Bed Combustion (CFBC) System'' during the quarter January--March 2004. The following tasks have been completed. First, plans for the renovation of space for a new Combustion Laboratory for the CFBC Facility have progressed smoothly. Second, the design calculations, including the mass balances, energy balances, heat transfer, and strength calculations have been completed. Third, considerable modifications have been made on the draft design of the CFBC Facility based on discussions conducted during the project kick-off meeting held on January 13, 2004 at the National Energy Technology Laboratory (NETL). Comments received from various experts were also used to improve the design. Finally, the drawings of all assembly parts have been completed in order to develop specifications for the fabrication of individual parts. At the same time, the proposed work for the next quarter has been outlined in this report.

  11. Fluidized bed combustion

    SciTech Connect

    Sowards, N.K.; Murphy, M.L.

    1991-10-29

    This patent describes a vessel. It comprises a fluid bed for continuously incinerating fuel comprising tire segments and the like which comprise metallic wire tramp and for concurrently removing tramp and bed materials at a bottom effluent exit means of the vessel, the vessel further comprising static air distributor means at the periphery of the bed comprising a substantially centrally unobstructed relatively large central region in which the fluid bed and fuel only are disposed and through which bed material and tramp migrate without obstruction to and through the effluent exit means, downwardly and inwardly stepped lower vessel wall means and a plurality of peripherally located centrally directed vertically and horizontally offset spaced air influent means surrounding the central region and associated with the stepped lower vessel wall means by which the bed is supported and fluidized.

  12. Subtask 3.12 - Oxygen-Fired CFBC

    SciTech Connect

    Douglas Hajicek; Mark Musich; Ann Henderson

    2007-02-28

    Traditionally, air is used as the source of oxygen for firing a combustion system. A fully oxygen-fired circulating fluidized-bed combustion (CFBC) system would result in the production of a flue gas stream consisting of mostly carbon dioxide and water. The concentrated carbon dioxide stream would be available for sequestering or other purposes. Temperatures in an oxygen-blown CFBC system would be controlled by a combination of flue gas recycle, solids recirculation, and by appropriately sizing and locating the amount of heat-transfer surface required. Flue gas recycle provides the additional gas required for adequate fluidization and circulation of solids replacing the nitrogen that would be present in an air-blown system. The amount of flue gas recycle will determine how much of the remaining heat from the coal combustion will have to be removed. If the amount of flue gas recycle required by increasing solids recirculation and oxygen staging is limited, introducing the pure oxygen at multiple locations in the combustor to result in a more even temperature profile should result in a more compact system, thus reducing initial capital costs for construction. The overall efficiency of the process should be greater than that of an air-blown system since less fuel is required for the creation of the same amount of energy. The Energy & Environmental Research Center (EERC) is in a unique position to advance this technology. It has a world-class CFBC pilot plant, has experience with firing a wide range of fuels in our air-fired CFBC pilot plant, has prior experience with oxygen-firing a slagging furnace system in a pulverized coal-fired mode with a bituminous coal, and has all of the components required for oxygen-firing right next to the CFBC pilot plant already in place. An engineering study was performed to identify methods, an overall appropriate configuration, and an operating strategy for a fully oxygen-fired CFBC pilot plant by: (1) developing a plan to optimize

  13. Fluidized bed combustion of coal

    NASA Astrophysics Data System (ADS)

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

    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.

  14. Reversed flow fluidized-bed combustion apparatus

    DOEpatents

    Shang, Jer-Yu; Mei, Joseph S.; Wilson, John S.

    1984-01-01

    The present invention is directed to a fluidized-bed combustion apparatus provided with a U-shaped combustion zone. A cyclone is disposed in the combustion zone for recycling solid particulate material. The combustion zone configuration and the recycling feature provide relatively long residence times and low freeboard heights to maximize combustion of combustible material, reduce nitrogen oxides, and enhance sulfur oxide reduction.

  15. PREFERENTIAL RECYCLING/REJECTION IN CFBC/FBC SYSTEMS USING TRIBOELECTROSTATIC SEPARATION

    SciTech Connect

    Heng Ban; John M. Stencel

    2004-12-01

    Circulating Fluidized Bed Combustion (CFBC) and Fluidized Bed Combustion (FBC) with recirculation are widely used technologies in the US for power generation. They have the advantage of fuel flexibility, and low NO{sub x} and SO{sub x} emissions. Typically, as partially combusted fuel is circulated in the system, only a split stream of this circulating stream is rejected, with the remainder recycled to the combustor. As a consequence, there is unburned carbon and partially used and valuable calcium hydroxide in the reject stream. If these useful materials in the reject stream can be recovered and sent back to the combustor, the efficiency of the system will be increased significantly and the equivalent emissions will be lower. This project studies an innovative concept to incorporate triboelectric separation into CFBC/FBC systems in order to preferentially split its recycle/reject streams based on material compositions of the particles. The objective is to answer whether useful constituents, like carbon, calcium carbonate and calcium hydroxide or oxide, can be selectively separated from combustion ash at elevated temperatures. Laboratory experimental studies are performed at temperatures from 25 C to 210 C,the data from which are presented in the form of recovery curves. These curves present quality-versus-quantity information useful for predicting the efficacy of triboelectric separation as applied to CFBC/FBC byproduct recycling and/or rejection.

  16. Pulsed atmospheric fluidized bed combustion

    SciTech Connect

    Not Available

    1992-05-01

    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.

  17. Fluidized bed coal combustion reactor

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    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.

  18. Fluidized bed coal combustion reactor

    SciTech Connect

    Moynihan, P.I.; Young, D.L.

    1981-09-01

    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. Official Gazette of the U.S. Patent and Trademark Office

  19. 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...

  20. Establishment of an Environmental Control Technology Laboratory with a Circulating Fluidized-Bed Combustion System

    SciTech Connect

    Wei-Ping Pan; Songgeng Li; John T. Riley

    2005-10-01

    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 July 1, 2005 through September 30, 2005. The following tasks have been completed. First, the construction of the Circulating Fluidized-Bed (CFB) Combustor Building was completed. The experimental facilities have been moved into the CFB Combustor Building. Second, the fabrication and manufacture of the CFBC Facility is in the final stage and is expected to be completed before November 30, 2005. Third, the drop tube reactor has been remodeled and installed to meet the specific requirements for the investigation of the effects of flue gas composition on mercury oxidation. This study will start in the next quarter. Fourth, the effect of sulfur dioxide on molecular chlorine via the Deacon reaction was investigated. The experimental results from this study are presented in this report. Finally, the proposed work for the next quarter is described in this report.

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

    PubMed

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

    2009-05-01

    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

  2. Reducing mode circulating fluid bed combustion

    DOEpatents

    Lin, Yung-Yi; Sadhukhan, Pasupati; Fraley, Lowell D.; Hsiao, Keh-Hsien

    1986-01-01

    A method for combustion of sulfur-containing fuel in a circulating fluid bed combustion system wherein the fuel is burned in a primary combustion zone under reducing conditions and sulfur captured as alkaline sulfide. The reducing gas formed is oxidized to combustion gas which is then separated from solids containing alkaline sulfide. The separated solids are then oxidized and recycled to the primary combustion zone.

  3. Characterization of a fluidized-bed combustion ash to determine potential for environmental impact. Final report

    SciTech Connect

    Hassett, D.J.; Henderson, A.K.; Pflughoeft-Hassett, D.F.; Mann, M.D.; Eylands, K.E.

    1997-10-01

    A 440-megawatt, circulating fluidized-bed combustion (CFBC), lignite-fired power plant is planned for construction in Choctaw County north of Ackerman, Mississippi. This power plant will utilize Mississippi lignite from the first lignite mine in that state. Malcolm Pirnie, Inc., is working with the power plant developer in the current planning and permitting efforts for this proposed construction project. In order to accommodate Mississippi state regulatory agencies and meet appropriate permit requirements, Malcolm Pirnie needed to provide an indication of the characteristics of the by-products anticipated to be produced at the proposed plant. Since the Mississippi lignite is from a newly tapped mine and the CFBC technology is relatively new, Malcolm Pirnie contacted with the Energy and Environmental Research Center (EERC) to develop and perform a test plan for the production and characterization of ash similar to ash that will be eventually produced at the proposed power plant. The work performed at the EERC included two primary phases: production of by-products in a bench-scale CFBC unit using lignite provided by Malcolm Pirnie with test conditions delineated by Malcolm Pirnie to represent expected operating conditions for the full-scale plant; and an extensive characterization of the by-products produced, focusing on Mississippi regulatory requirements for leachability, with the understanding that return of the by-product to the mine site was an anticipated by-product management plan. The overall focus of this project was the environmental assessment of the by-product expected to be produced at the proposed power plant. Emphasis was placed on the leachability of potentially problematic trace elements in the by-products. The leaching research documented in this report was performed to determine trends of leachability of trace elements under leaching conditions appropriate for evaluating land disposal in monofills, such as returning the by-products to the mine

  4. The long term behaviour of CFBC ash-water systems.

    PubMed

    Anthony, E J; Bulewicz, Elzbieta M; Dudek, Krystyna; Kozak, Adam

    2002-01-01

    Circulating fluidized bed combustion (CFBC) ashes in contact with water, whether in liquid or vapour form, exhibit considerable chemical activity, which can continue for more than a year. From the point of view of the setting of CFBC ash-water mixtures and their behaviour, the formation of gypsum and of ettringite are important. The crystallisation of ettringite is associated with expansion of the set mass and absorption of water into the solids, but the ash-water system as a whole shrinks. The extent of ettringite formation is reduced if carbonation of free lime can take place. There is little carbonation if the set solids are covered by water but if contact with air is not restricted, the ettringite formed earlier slowly decomposes, its place being taken by calcite and gypsum. The fate of the aluminium from decomposed ettringite is uncertain; no new crystalline Al compounds are found. It appears that ultimately most analytical lime present can become carbonated. This is environmentally beneficial since it reduces chemical activity in the landfill, and reduces the amount of CO2 released due to limestone use. The main features of the behaviour of CFBC ash-water mixtures can be reproduced in model systems (CaO-Al2O3-CaSO4-H2O) but that of real ashes is complicated by the presence of silicates and possible interactions between silica and the strongly alkaline aqueous medium. Also, aluminates present in the ash are probably more active with respect to ettringite formation than pure aluminum hydroxide. PMID:11942710

  5. Pressurized fluidized-bed combustion

    SciTech Connect

    Not Available

    1980-10-01

    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)

  6. 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...

  7. Volatilization of the heavy metals during circulating fluidized bed combustion of forest residue

    SciTech Connect

    Lind, T.; Kauppinen, E.I.; Valmari, T.; Sfiris, G.; Nilsson, K.; Maenhaut, W.

    1999-02-01

    Increasing interest in using biomass for energy production has created a need to establish a method for its sustainable utilization. During combustion, the inorganic incombustible species in the biomass are converted into ash. The environmental impact on the heavy metals contained in the combustion product ash depends on the speciation of the heavy metals and the size distributions of the heavy metals in the ash. Therefore, the behavior of cadmium, lead, copper, and zinc was studied experimentally during circulating fluidized bed combustion (CFBC) of Swedish forest residue. The size distributions and concentrations of the heavy metals in the fly ash particles and in the gas phase were determined by low-pressure impacts and filters upstream of the convective back pass at 830 C. Downstream of the convective back pass at T = 150 C, the size distributions were determined. The fly ash from CFBC was found to contain two separate particle classes. Fine particles consisted mainly of KCl, and coarse particles contained as major elements Ca and Si. Major fraction of all the studied heavy metals were found in the coarse fly ash particles at location 1 at 830 C; 7--26% of Pb, 24--27% of Cu, 1--8% of Cd, and less than 1% of Zn were found in the gas phase. The gas-to-particle conversion route for Cd, Pb, and Cu was found by chemical surface reaction, probably with silicates. None of the studied heavy metals were enriched in the fine particles at the inlet of the electrostatic precipitator.

  8. MUNICIPAL WASTE COMBUSTION ASSESSMENT: FLUIDIZED BED COMBUSTION

    EPA Science Inventory

    The report documents the results of an assessment of fluidized bed combustors (FBCs) to minimize air emissions from municipal waste combustors (MWCs). Objectives of the assessment were to identify the population of existing and planned refuse fired FBC facilities in the U.S., exa...

  9. Design assessment of a 150 kWt CFBC Test Unit

    SciTech Connect

    Batu, A.; Selcuk, N.; Kulah, G.

    2010-04-15

    For clean and efficient energy generation from coal, the most suitable technology known to date is 'Fluidized Bed Combustion' technology. Applications of circulating fluidized bed (CFB) combustion technology have been steadily increasing in both capacity and number over the past decade. Designs of these units have been based on the combustion tests carried out in pilot scale facilities to determine the combustion and desulfurization characteristics of coal and limestone reserves in CFB conditions. Similarly, utilization of Turkish lignites in CFB boilers necessitates adaptation of CFB combustion technology to these resources. However, the design of these test units are not based on firing coals with high ash, volatile matter and sulfur contents like Turkish lignites. For this purpose, a 150 kWt CFB combustor test unit is designed and constructed in Chemical Engineering Department of Middle East Technical University, based on the extensive experience acquired at the existing 0.3 MWt Bubbling Atmospheric Fluidized Bed Combustor (AFBC) Test Rig. Following the commissioning tests, a combustion test is carried out for investigation of combustion characteristics of Can lignite in CFB conditions and for assessment of the design of test unit. Comparison of the design outputs with experimental results reveals that most of the predictions and assumptions have acceptable agreement with the operating conditions. In conclusion, the performance of 150 kWt CFBC Test Unit is found to be satisfactory to be utilized for the long term research studies on combustion and desulfurization characteristics of indigenous lignite reserves in circulating fluidized bed combustors. (author)

  10. Pyrolysis reactor and fluidized bed combustion chamber

    DOEpatents

    Green, Norman W.

    1981-01-06

    A solid carbonaceous material is pyrolyzed in a descending flow pyrolysis reactor in the presence of a particulate source of heat to yield a particulate carbon containing solid residue. The particulate source of heat is obtained by educting with a gaseous source of oxygen the particulate carbon containing solid residue from a fluidized bed into a first combustion zone coupled to a second combustion zone. A source of oxygen is introduced into the second combustion zone to oxidize carbon monoxide formed in the first combustion zone to heat the solid residue to the temperature of the particulate source of heat.

  11. Pulsed atmospheric fluidized bed combustion

    SciTech Connect

    Not Available

    1992-08-01

    The general specifications for a Pulsed Atmospheric Fluidized Bed Combustor Design Report (PAFBC) plant are presented. The design tasks for the PAFBC are described in the following areas: Coal/Limestone preparation and feed system; pulse combustor; fluidized bed; boiler parts; and ash handling system.

  12. A pilot-plant study for destruction of PCBs in contaminated soils using fluidized bed combustion technology.

    PubMed

    Desai, Dilip L; Anthony, Edward J; Wang, Jinsheng

    2007-08-01

    Destruction of polychlorinated biphenyls (PCBs) in contaminated soils and wastes using circulating fluidized bed combustion (CFBC) technology was studied using a pilot plant and simulated waste material. The results show that the technology is effective and particularly promising for treatment of PCB-containing materials like the toxic sludge from a large contaminated site. Destruction of the toxics in the gas phase appears to be very fast, and over 99.9999% destruction and removal efficiency can be achieved in the temperature range 875-880 degrees C. Heat transfer in the fluidized bed also appears adequate. Toxic residues in treated soil can be reduced to very low levels. Rate-controlling factors of the decontamination process are analyzed, and key issues for determination of the process conditions are discussed. PMID:16901621

  13. Loop-bed combustion apparatus

    DOEpatents

    Shang, Jer-Yu; Mei, Joseph S.; Slagle, Frank D.; Notestein, John E.

    1984-01-01

    The present invention is directed to a combustion apparatus in the configuration of a oblong annulus defining a closed loop. Particulate coal together with a sulfur sorbent such as sulfur or dolomite is introduced into the closed loop, ignited, and propelled at a high rate of speed around the loop. Flue gas is withdrawn from a location in the closed loop in close proximity to an area in the loop where centrifugal force imposed upon the larger particulate material maintains these particulates at a location spaced from the flue gas outlet. Only flue gas and smaller particulates resulting from the combustion and innerparticle grinding are discharged from the combustor. This structural arrangement provides increased combustion efficiency due to the essentially complete combustion of the coal particulates as well as increased sulfur absorption due to the innerparticle grinding of the sorbent which provides greater particle surface area.

  14. Burning waste with FBC. [Fluidized Bed Combustion

    SciTech Connect

    Salaff, S.

    1991-11-01

    This article examines fluidized bed combustion as a method of choice for disposing for waste economically and within the bounds of rigid environmental standards. The topics discussed in the article include technology scaleup, wood and fossil wastes, municipal and hospital wastes, fuel flexibility, and a sidebar on the fluidized bed combustion technology. The waste fuels of major interest are various low grade liquid and solid residues from the coal, oil, forest products and automotive industries, as well as post-harvest biomass and municipal refuse.

  15. Fluidized-bed combustion reduces atmospheric pollutants

    NASA Technical Reports Server (NTRS)

    Jonke, A. A.

    1972-01-01

    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.

  16. FBC: Gaining acceptance. [Fluidized Bed Combustion

    SciTech Connect

    Gawlicki, S.M.

    1991-04-01

    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.

  17. Atmospheric fluidized bed combustion advanced concept system

    SciTech Connect

    Not Available

    1992-05-01

    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.

  18. Pulsed atmospheric fluidized bed combustion. Final report

    SciTech Connect

    1998-03-01

    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.

  19. Feasibility of manufacturing geopolymer bricks using circulating fluidized bed combustion bottom ash.

    PubMed

    Chen, Chen; Li, Qin; Shen, Lifeng; Zhai, Jianping

    2012-06-01

    This paper presents a study on geopolymer bricks manufactured using bottom ash from circulating fluidized bed combustion (CFBC). The alkali activators used for synthesis were sodium silicate, sodium hydroxide, and potassium hydroxide and lithium hydroxide solutions. The study included the impact of alkali activator on compressive strength. The reaction products were analysed by XRD, FT-IR and SEM/EDS. The compressive strength of bricks was dependent on the modulus of the sodium silicate activator and the type and concentration of alkali activator. The highest compressive strength could be gained when the modulus was 1.5, and the value could reach 16.1 MPa (7 d after manufacture) and 21.9 MPa (28 d after manufacture). Under pure alkaline systems, the compressive strength was in the order of 10 M KOH > 10 M NaOH > 5 M LiOH > 5 M KOH > 5 M NaOH. Quartz was the only crystalline phase in the original bottom ash, and no new crystalline phase was found after the reaction. The main product of reaction was amorphous alkali aluminosilicate gel and a small amount of crystalline phase was also found by SEM. PMID:22856304

  20. CIRCULATING MOVING BED COMBUSTION PROOF OF CONCEPT

    SciTech Connect

    Jukkola, Glen

    2010-06-30

    Circulating Moving Bed (CMB) combustion technology has its roots in traditional circulating fluidized bed technology and involves a novel method of solid fuel combustion and heat transfer. CMB technology represents a step change in improved performance and cost relative to conventional PC and FBC boilers. The CMB heat exchanger preheats the energy cycle working fluid, steam or air, to the high temperature levels required in systems for advanced power generation. Unique features of the CMB are the reduction of the heat transfer surfaces by about 60% as a result of the enhanced heat transfer rates, flexibility of operation, and about 30% lower cost over existing technology. The CMB Phase I project ran from July 2001 through March 2003. Its objective was to continue development of the CMB technology with a series of proof of concept tests. The tests were conducted at a scale that provided design data for scale up to a demonstration plant. These objectives were met by conducting a series of experiments in ALSTOM Power’s Multi-use Test Facility (MTF). The MTF was modified to operate under CMB conditions of commercial interest. The objective of the tests were to evaluate gas-to-solids heat transfer in the upper furnace, assess agglomeration in the high temperature CMB bubbling bed, and evaluate solids-to-tube heat transfer in the moving bed heat exchanger. The Phase I program results showed that there are still some significant technical uncertainties that needed to be resolved before the technology can be confidently scaled up for a successful demonstration plant design. Work remained in three primary areas: • scale up of gas to solid heat transfer • high temperature finned surface design • the overall requirements of mechanical and process design. The CMB Phase II workscope built upon the results of Phase I and specifically addressed the remaining technical uncertainties. It included a scaled MTF heat transfer test to provide the necessary data to scale up gas

  1. Fluidized-bed calciner with combustion nozzle and shroud

    DOEpatents

    Wielang, Joseph A.; Palmer, William B.; Kerr, William B.

    1977-01-01

    A nozzle employed as a burner within a fluidized bed is coaxially enclosed within a tubular shroud that extends beyond the nozzle length into the fluidized bed. The open-ended shroud portion beyond the nozzle end provides an antechamber for mixture and combustion of atomized fuel with an oxygen-containing gas. The arrangement provides improved combustion efficiency and excludes bed particles from the high-velocity, high-temperature portions of the flame to reduce particle attrition.

  2. Emission characteristics of co-combustion of sewage sludge with olive cake and lignite coal in a circulating fluidized bed.

    PubMed

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

    2004-01-01

    In this study, a circulating fluidized bed (CFB) of 125 mm diameter and 1800mm 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, CmHn) were measured in the flue gas, as well as temperature and pressure distributions along the bed. Combustion efficiencies of sludge + olive cake and sludge + lignite coal mixtures were calculated, and the optimum conditions for operating parameters were discussed. The results have shown that the combustion mainly takes place in the upper regions of the main column where the temperature reaches 900 degrees C. SS + Coal burn in the CFB with an efficiency of 95.14% to 96.18%, which is considered to be quite good. When burning sludge mixed with olive cake, appreciable amounts of CO and unburned hydrocarbons are formed and the combustion efficiency drops to 92.93%. CO and CmHn emissions are lower when lignite coal is mixed with various amounts of SS than the emissions when the coal is burned alone. As the %SS is increased in the fuel mixture, the SO2 emission decreases. NOx emissions are slightly higher. When burning sludge mixed with olive cake, SO2 and NOx emissions are slightly higher. CO and CmHn emissions decrease sharply when SS is mixed with 5%wt. olive cake. With increasing sludge ratio these emissions increase due to the unburned hydrocarbons. As a result of this study, it is believed that SS can be burned effectively in a CFBC together with other fuels, especially with olive cake (OC). OC will be a good additive fuel for the combustion of lower quality fuels. PMID:15137713

  3. CHARACTERIZATION OF SOLID RESIDUES FROM FLUIDIZED-BED COMBUSTION UNITS

    EPA Science Inventory

    The report gives results of physical and chemical characterizations of samples of spent bed material and of flyash from three experimental atmospheric and pressurized fluidized-bed combustion (FBC) units. It also gives results of characterization of samples of bed material which ...

  4. Characteristics of oily sludge combustion in circulating fluidized beds.

    PubMed

    Zhou, Lingsheng; Jiang, Xiumin; Liu, Jianguo

    2009-10-15

    Incineration of oily sludge in circulating fluidized beds may be an effective way for its management in some cases. The objective of the present paper is to investigate combustion characteristics of oily sludge, which would be helpful and useful for the design and simulation of a circulating fluidized bed. Firstly, the pyrolysis and combustion of oily sludge were studied through some thermal analyses, which included the thermogravimetric (TG) analysis and the differential thermal analytical (DTA) analysis. It was found that the combustion of oily sludge might be the combustion of its pyrolysis products. Secondly, an experiment for measuring of main components of the volatile from oily sludge pyrolysis was carried out. Some mathematic correlations about the compositions of volatile from oily sludge devolatilization were achieved from the experimental results. Finally, the combustion characteristics of oily sludge was studied in a lab-scale circulating fluidized bed, which could obtain some information about the location of release and combustion of the volatiles. PMID:19482424

  5. 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...

  6. Staged fluidized-bed combustion and filter system

    DOEpatents

    Mei, Joseph S.; Halow, John S.

    1994-01-01

    A staged fluidized-bed combustion and filter system for substantially reducing the quantity of waste through the complete combustion into ash-type solids and gaseous products. The device has two fluidized-bed portions, the first primarily as a combustor/pyrolyzer bed, and the second as a combustor/filter bed. The two portions each have internal baffles to define stages so that material moving therein as fluidized beds travel in an extended route through those stages. Fluidization and movement is achieved by the introduction of gases into each stage through a directional nozzle. Gases produced in the combustor/pyrolyzer bed are permitted to travel into corresponding stages of the combustor/filter bed through screen filters that permit gas flow but inhibit solids flow. Any catalyst used in the combustor/filter bed is recycled. The two beds share a common wall to minimize total volume of the system. A slightly modified embodiment can be used for hot gas desulfurization and sorbent regeneration. Either side-by-side rectangular beds or concentric beds can be used. The system is particularly suited to the processing of radioactive and chemically hazardous waste.

  7. Flow and combustion characteristics of a 2-dimensional spouted bed

    NASA Astrophysics Data System (ADS)

    Sawyer, R. F.; Hart, J. R.; Ohtake, K.

    1982-03-01

    A two dimensional spouted bed laboratory combustor was designed and constructed with the objective of studying the interaction among the gas flow, particle flow, and combustion. The facility, designed for a maximum thermal power of 20 kW, has a quartz front wall providing full optical access to particle flows and combustion processes. The combustor was characterized in terms of pressure, temperature, gas velocity, and particle velocity profiles and operating limits. Initial studies employed premixed propane and air and a fixed bed height, bed material, injector slot width, and combustor geometry. As in previous investigations of axisymmetric spouted beds, the ratio of particle mass circulation rate to jet mass flow rate was observed to be about ten. Combustion increased this ratio by about 10%. A pulsating mode of operation was noted with a characteristic frequency of about 10 Hz, controlled by the interaction of the particle and gas flows.

  8. Investigation on Agropellet Combustion in the Fluidized Bed

    NASA Astrophysics Data System (ADS)

    Isemin, R. L.; Konayahin, V. V.; Kuzmin, S. N.; Zorin, A. T.; Mikhalev, A. V.

    Agricultural wastes (straw, sunflower or millet husk, etc.) are difficult to use as fuel because of low bulk density and relatively big ash content with a low melting point. It is possible to produce agropellets of agricultural wastes which are suggested to combust in a fluidized bed of pellets alone, their char particles and ash. The characteristics of the process of fluidization of agropellets are investigated at room temperature. The experiments on agropellet combustion in a fluidized bed are carried out in an experimental set-up. The results of the experiments have shown that in such a bed the pellets produced of straw and millet husk combust with the same rate as those of wood though the latter contain 8.76 - 19.4 times less ash. The duration of combustion of the same portion of straw pellets in a fluidized bed is 3.74 - 7.01 times less than the duration of combustion of cut straw in a fixed bed. Besides, the movement of agropellets prevents agglomeration and slagging of a boiler furnace.

  9. Kinetics of fluidized bed combustion of wood pellets

    SciTech Connect

    Leckner, B.; Hansson, K.M.; Tullin, C.; Borodulya, A.V.; Dikalenko, V.I.; Palchonok, G.I.

    1999-07-01

    Devolatilization and char combustion of a single wood pellet in a fluidized bed has been studied. The effect of operation parameters (bed temperature, bed particle size, oxygen concentration) and pellet characteristics has been investigated. A simplified analytical model of heat-transfer controlled pyrolysis has been developed to interpret the measured volatiles release time. The model predictions are in a good agreement with the experimental data, provided that the initial physical properties of the pellet are used. The model can be used to estimate the devolatilization times in other combustion systems. Kinetic parameters of char combustion are obtained, based on the measured burnout times and simple model considerations. The physical properties of wood pellets need further study.

  10. Combustion model for staged circulating fluidized bed boiler

    NASA Astrophysics Data System (ADS)

    Fang, Jianhua; Lu, Qinggang; Wang, Bo; Pan, Zhonggang; Wang, Dasan

    1997-03-01

    A mathematical model for atmospheric staged circulating fluidized bed combustion, which takes fluid dynamics, combustion, heat transfer, pollutants formation and retention, into account was developed in the Institute of Engineering Thermophysics (IET) recently. The model of gas solid flow at the bottom of the combustor was treated by the two-phase theory of fluidized bed and in the upper region as a core-annulus flow structure. The chemical species CO, CO2, H2, H2O, CH4, O2 and N2 were considered in the reaction process. The mathematical model consisted of sub-models of fluid namics, coal heterogeneous and gas homogeneous chemical reactions, heat transfer, particle fragmentation and attrition, mass and energy balance etc. The developed code was applied to simulate an operating staged circulating fluidized bed combustion boiler of early design and the results were in good agreement with the operating data. The main submodels and simulation results are given in this paper.

  11. Direct combustion of olive cake using fluidized bed combustor

    SciTech Connect

    Khraisha, Y.H.; Hamdan, M.A.; Qalalweh, H.S.

    1999-05-01

    A fluidized bed combustor of 0.146 m diameter and 1 m length was fabricated from stainless steel to burn olive cake. Initially, and in order to obtain fluidization, the system was operated under cold conditions using a sand with particle size in the range of 500 to 710 microns. The continuous combustion experiments were carried out under controlled conditions, such that the effects of bed temperature, olive cake feed rate, fluidization velocity, and particle size on combustion efficiency and flue gas composition were investigated. It was found that the combustion efficiency decreases with the bed temperature, fluidization velocity, and the feed rate, while it increases with the particle size used. Further, the gas products analysis carried out using a gas chromatography analyzer have shown a nonmeasured amount of SO{sub 2}, and small amounts of CO. Finally, the temperature distribution along the bed indicated that the temperature throughout the bed is fairly uniform, demonstrating a good mixing of reactants, which is important for efficient combustion.

  12. 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...

  13. Combustion of oil palm solid wastes in fluidized bed combustor

    SciTech Connect

    Shamsuddin, A.H.; Sopian, K.

    1995-12-31

    The palm oil industry of Malaysia is the largest in the world producing about 55% of the world production. The industry has approximately 270 mills throughout the country with processing sizes ranging from 10 tonnes/hour to 120 tonnes/hour. All mills produce solid wastes, about 50% of the fresh fruit bunches in terms of weight. The solid wastes produced are in the form of empty fruit bunches, fibers and shells. These wastes have high energy value, ranging from 14 to 18 MJ/kg. The industry is currently self-sufficient in terms of energy. Fibers and shell wastes are being used as boiler fuel to raise steam for electrical power production and process steam. However, the combustion technology currently being employed is obsolete with low efficiency and polluting. A fluidized bed combustor pilot plant is designed and constructed at Combustion Research Laboratory, Universiti Kebangsaan Malaysia. The combustor is made up of 600 mm {times} 900 mm rectangular bed filled with sand up to 400 mm height, static. A bank of heat transfer tubes is imbedded in the bed, designed to absorb 50% of heat released by the fuel in the bed. The remaining heat is transferred in tubes placed on the wall of the freeboard area. Experimental studies were carried out in the pilot plant using palm oil solid wastes. The combustion temperatures were maintained in the range 800--900 C. The performance of the combustor was evaluated in terms of combustion and boiler efficiencies and flue gas emissions monitored.

  14. Decontamination of combustion gases in fluidized bed incinerators

    DOEpatents

    Leon, Albert M.

    1982-01-01

    Sulfur-containing atmospheric pollutants are effectively removed from exit gas streams produced in a fluidized bed combustion system by providing a fluidized bed of particulate material, i.e. limestone and/or dolomite wherein a concentration gradient is maintained in the vertical direction. Countercurrent contacting between upwardly directed sulfur containing combustion gases and descending sorbent particulate material creates a concentration gradient across the vertical extent of the bed characterized in progressively decreasing concentration of sulfur, sulfur dioxide and like contaminants upwardly and decreasing concentration of e.g. calcium oxide, downwardly. In this manner, gases having progressively decreasing sulfur contents contact correspondingly atmospheres having progressively increasing concentrations of calcium oxide thus assuring optimum sulfur removal.

  15. Fluidized bed combustion tested for Turkish oil shales

    SciTech Connect

    Not Available

    1986-09-01

    About 7.5 billion tons of lignite and 5 billion tons of oil shale deposits are potential energy sources and therefore potential air pollution sources for Turkey. The low calorific value, and high ash and sulfur contents of these fuels render fluidized bed combustion a promising method of utilization. A fluidized bed combustion system with a nominal capacity of 418,000 to 627,000 kilojoules per hour for producing hot water has been designed and constructed at Istanbul Technical University. This paper lists the important characteristics of the main Turkish lignite and oil shale reserves, and the specifications of the pilot-scale fluidized-bed combustor designed to burn these fuels.

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

    SciTech Connect

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

    1995-04-01

    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.

  17. Atmospheric fluidized bed combustion advanced concept system. Final report

    SciTech Connect

    Not Available

    1992-05-01

    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.

  18. Pressurized fluidized-bed combustion technology exchange workshop

    SciTech Connect

    ,

    1980-04-01

    The pressurized fluidized-bed combustion technology exchange workshop was held June 5 and 6, 1979, at The Meadowlands Hilton Hotel, Secaucus, New Jersey. Eleven papers have been entered individually into EDB and ERA. The papers include reviews of the US DOE and EPRI programs in this area and papers by Swedish, West German, British and American organizations. The British papers concern the joint program of the USA, UK and FRG at Leatherhead. The key factor in several papers is the use of fluidized bed combustors, gas turbines, and steam turbines in combined-cycle power plants. One paper examines several combined-cycle alternatives. (LTN)

  19. Regeneration of lime from sulfates for fluidized-bed combustion

    DOEpatents

    Yang, Ralph T.; Steinberg, Meyer

    1980-01-01

    In a fluidized-bed combustor the evolving sulfur oxides are reacted with CaO to form calcium sulfate which is then decomposed in the presence of carbonaceous material, such as the fly ash recovered from the combustion, at temperatures of about 900.degree. to 1000.degree. C., to regenerate lime. The regenerated lime is then recycled to the fluidized bed combustor to further react with the evolving sulfur oxides. The lime regenerated in this manner is quite effective in removing the sulfur oxides.

  20. Coal-feeding mechanism for a fluidized bed combustion chamber

    DOEpatents

    Gall, Robert L.

    1981-01-01

    The present invention is directed to a fuel-feeding mechanism for a fluidized bed combustor. In accordance with the present invention a perforated conveyor belt is utilized in place of the fixed grid normally disposed at the lower end of the fluidized bed combustion zone. The conveyor belt is fed with fuel, e.g. coal, at one end thereof so that the air passing through the perforations dislodges the coal from the belt and feeds the coal into the fluidized zone in a substantially uniform manner.

  1. Bed material agglomeration during fluidized bed combustion. Technical progress report, September 30, 1992--December 31, 1992

    SciTech Connect

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

    1993-02-01

    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.

  2. Bed material agglomeration during fluidized bed combustion. Technical progress report, January 1, 1993--March 31, 1993

    SciTech Connect

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

    1993-04-01

    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 and to relate these reactions to specific causes. A survey of agglomeration and deposit formation in industrial fluidized bed boilers is in progress. Preliminary results indicate that at least five boilers were experiencing some form of bed material agglomeration. In these instances it was observed that large particles were forming within the bed which were larger that the feed. Four operators could confirm that the larger bed particles had formed due to bed particles sticking together or agglomerating. Deposit formation was reported at nine sites with these deposits being found most commonly at coal feed locations and in cyclones. Other deposit locations included side walls and return loops. Examples of these agglomerates and deposits have been received from five of the surveyed facilities. Also during this quarter, a bulk sample of Illinois No. 6 coal was obtained from the Fossil Energy Program at Ames Laboratory here at Iowa State University and prepared for combustion tests. This sample was first ground to a top-size of 3/8`` using a jaw crusher then a size fraction of 3/8`` {times} 8 (US mesh) was then obtained by sieving using a Gilson Test-Master. This size fraction was selected for the preliminary laboratory-scale experiments designed to simulate the dense bed conditions that exist in the bottom of CFB combustors. To ensure uniformity of fuel composition among combustion runs, the sized coal was riffled using, a cone and long row method and stored in bags for each experiment. During this quarter additional modifications were made to achieve better control of fluidization regimes and to aid in monitoring the hydrodynamic and chemical conditions within the reactor.

  3. Task 3.8 - pressurized fluidized-bed combustion

    SciTech Connect

    1995-03-01

    The focus of this work on pressurized fluidized-bed combustion (PFBC) is the development of sorbents for in-bed alkali control. The goal is to generate fundamental process information for development of a second-generation PFBC. Immediate objectives focus on the performance of sulfur sorbents, fate of alkali, and the Resource Conservation and Recovery Act (RCRA) heavy metals. The studies reported here focus on emission control strategies applied in the bed. Data from shakedown testing, alkali sampling, sulfur sorbent performance tests, and refuse-derived fuel (RDF) and lignite combustion tests are presented in detail. Initial results from the characterization of alkali gettering indicate that in-bed getters can remove a significant amount of alkali from the bed. Using kaolin as a sorbent, sodium levels in the flue gas were reduced from 3.6 ppm to less than 0.22 ppm. Sulfur was also reduced by 60% using the kaolin sorbent. Preliminary sulfur sorbent testing, which was designed to develop a reliable technique to predice sorbent performance, indicate that although the total sulfur capture is significantly lower than that observed in a full-scale PFBC, the emission trends are similar. RDF and RDF-lignite fuels had combustion efficiencies exceeding 99.0% in all test cases. Sulfur dioxide emission was significantly lower for the RDF fuels than for lignite fuel alone. Nitrogen oxide emission was also lower for the RDF-based fuels than for the lignite fuel. Both emission gases were well below current regulatory limits. Carbon monoxide and hydrocarbon emissions appeared to be slightly higher for the fuels containing RDF, but were below 9 ppm for the worst case. Analysis of volatile organic compound emission does not indicate an emission problem for these fuels. Chromium appears to be the only RCRA metal that might present some disposal problem; however, processing of the RDF with the wet resource recovery method should reduce chromium levels. 2 refs., 13 figs., 15 tabs.

  4. Physicochemical characterizations of limestone for fluidized-bed coal combustion

    SciTech Connect

    Fuller, E.L. Jr.; Yoos, T.R. III; Walia, D.S.

    1981-05-01

    This study is an investigation of the physicochemical characteristics of three limestone samples, Quincy limestone (-20 + 60), Franklin limestone (-12 + 30), and Franklin limestone (-6 + 16), currently being tested at Oak Ridge National Laboratory for use in a fluidized-bed coal combustion unit. By correlating the chemistry, mineralogy, and surface area of these samples with empirical data obtained at Argonne National Laboratory, the sulfur capture ability and performance of these limestones can be loosely predicted. X-ray fluorescence and neutron activation analysis revealed a very high calcium content and very low concentrations of other elements in the three samples. X-ray diffraction patterns and petrographic examination of the limestone grains detected essentially no dolomite in the Quincy limestone or the fine Franklin limestone samples. The coarse Franklin limestone sample showed dolomite to be present in varying amounts up to maximum of 2.75%. Limited surface chemistry investigations of the samples were undertaken. Limestone and dolostone resources of the Tennessee Valley Authority region are widespread and abundant, and judged sufficient to meet industrial demand for many years. No problems are anticipated in securing limestone or dolostone supplies for a commercial fluidized-bed combustion plant in the Tennessee Valley Authority region. Transportation facilities and costs for limestone or dolostone will influence the siting of such a commercial fluidized-bed combustion plant. The most promising location in the Tennessee Valley Authority region at this time is Paducah, Kentucky.

  5. Combustion of waste fuels in a fluidized-bed boiler

    SciTech Connect

    Zylkowski, J.; Ehrlich, S.

    1983-01-01

    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 Northern States Power (NSP) Company converted their French Island Unit No. 2 stoker-fired boiler to a fluidized-bed combustor designed to burn wood waste. NSP and EPRI are investigating cofiring other waste fuels with wood waste. Topics considered include fluidized-bed boiler conversion, fuel resources, economic justification, environmental considerations, the wood-handling system, an auxiliary fuel system, the air quality control system, ash handling and disposal, and the alternate fuels test program.

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

    SciTech Connect

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

    1980-01-01

    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.

  7. Reduced bed agglomeration by co-combustion biomass with peat fuels in a fluidized bed

    SciTech Connect

    Karin Lundholm; Anders Nordin; Marcus Oehman; Dan Bostroem

    2005-12-01

    Fluidized bed combustion is an energy conversion technology that is very suitable for biomass combustion because of its fuel flexibility and low process temperatures. However, agglomeration of bed material may cause severe operating problems. To prevent or at least reduce this, peat has been suggested as an additive to the main fuels. Nevertheless, the characteristics of peat fuels vary and there is limited information of the effect of different peat fuels and of the mechanisms behind the agglomeration prevention. The objectives of the present work were therefore to: (I) quantify the potential positive effect by co-combustion peat with forest fuels in terms of initial agglomeration temperatures; (ii) determine the amount of peat fuel that is needed to significantly reduce the agglomeration tendencies; and, if possible, (iii) elucidate the governing mechanisms. The results showed that all peat fuels prevented agglomeration in the studied interval of 760-1020{sup o}C and even as little as 5% peat fuel was found to have significant effects. The results also indicated that the mechanism of the agglomeration prevention varies between different peat fuels. Possible mechanisms are the minerals in the peat fuel retain alkali, which then is either elutriated up from the bed or captured in the bed; calcium and other refractory elements increase the melting temperature and thereby counteract the melting of alkali; and sulfur reacts with alkali metals and the alkali sulfates is either elutriated up from the bed or prevents agglomeration by increased melting temperature and lowered viscosity. Results from elemental analysis of the coating on bed particles showed that all mixtures with peat fuel resulted in a decreased or unchanged fraction of potassium and an increased fraction of aluminum in the coatings. The results also indicated a complex relationship between the fuel inorganic contents and the agglomeration process. 21 refs., 6 figs., 5 tabs.

  8. Combustion of textile residues in a packed bed

    SciTech Connect

    Ryu, Changkook; Phan, Anh N.; Sharifi, Vida N.; Swithenbank, Jim

    2007-08-15

    Textile is one of the main components in the municipal waste which is to be diverted from landfill for material and energy recovery. As an initial investigation for energy recovery from textile residues, the combustion of cotton fabrics with a minor fraction of polyester was investigated in a packed bed combustor for air flow rates ranging from 117 to 1638 kg/m{sup 2} h (0.027-0.371 m/s). Tests were also carried out in order to evaluate the co-combustion of textile residues with two segregated waste materials: waste wood and cardboard. Textile residues showed different combustion characteristics when compared to typical waste materials at low air flow rates below 819 kg/m{sup 2} h (0.186 m/s). The ignition front propagated fast along the air channels randomly formed between packed textile particles while leaving a large amount of unignited material above. This resulted in irregular behaviour of the temperature profile, ignition rate and the percentage of weight loss in the ignition propagation stage. A slow smouldering burn-out stage followed the ignition propagation stage. At air flow rates of 1200-1600 kg/m{sup 2} h (0.272-0.363 m/s), the bed had a maximum burning rate of about 240 kg/m{sup 2} h consuming most of the combustibles in the ignition propagation stage. More uniform combustion with an increased burning rate was achieved when textile residues were co-burned with cardboard that had a similar bulk density. (author)

  9. Element associations in ash from waste combustion in fluidized bed

    SciTech Connect

    Karlfeldt Fedje, K.; Rauch, S.; Cho, P.; Steenari, B.-M.

    2010-07-15

    The incineration of MSW in fluidized beds is a commonly applied waste management practice. The composition of the ashes produced in a fluidized bed boiler has important environmental implications as potentially toxic trace elements may be associated with ash particles and it is therefore essential to determine the mechanisms controlling the association of trace elements to ash particles, including the role of major element composition. The research presented here uses micro-analytical techniques to study the distribution of major and trace elements and determine the importance of affinity-based binding mechanisms in separate cyclone ash particles from MSW combustion. Particle size and the occurrence of Ca and Fe were found to be important factors for the binding of trace elements to ash particles, but the binding largely depends on random associations based on the presence of a particle when trace elements condensate in the flue gas.

  10. Pressurized circulating fluidized-bed combustion for power generation

    SciTech Connect

    Weimer, R.F.

    1995-08-01

    Second-generation Pressurized Circulating Fluidized Bed Combustion (PCFBC) is the culmination of years of effort in the development of a new generation of power plants which can operate on lower-quality fuels with substantially improved efficiencies, meet environmental requirements, and provide a lower cost of electricity. Air Products was selected in the DOE Clean Coal Technology Round V program to build, own, and operate the first commercial power plant using second-generation PCFBC technology, to be located at an Air Products chemicals manufacturing facility in Calvert City, Kentucky. This paper describes the second-generation PCFBC concept and its critical technology components.

  11. Advanced modeling of nitrogen oxide emissions in circulating fluidized bed combustors: Parametric study of coal combustion and nitrogen compound chemistries

    SciTech Connect

    Kilpinen, P.; Kallio, S.; Hupa, M.

    1999-07-01

    This paper describes work-in-progress aimed at developing an emission model for circulating fluidized bed combustors using detailed homogeneous and heterogeneous chemical kinetics. The main emphasis is on nitrogen oxides (NO{sub x}, N{sub 2}O) but also unburned gases (CO, C{sub x}H{sub y}) and sulfur dioxide (SO{sub 2}) will be investigated in the long run. The hydrodynamics is described by a 1.5-dimensional model where the riser is divided into three regions: a dense bubbling bed at the bottom, a vigorously mixed splash zone, and a transport zone. The two latter zones are horizontally split into a core region and an annular region. The solids circulation rate is calculated from the known solids inventory and the pressure and mass balances over the entire circulation loop. The solids are divided into classes according to size and type or particle. The model assumes instantaneous fuel devolatilization at the bottom and an even distribution of volatiles in the suspension phase of the dense bed. For addition of secondary air, a complete penetration and an instantaneous mixing with the combustor gases in the core region is assumed. The temperature distribution is assumed to be known, and no energy balance is solved. A comprehensive kinetic scheme of about 300 elementary gas-phase reactions is used to describe the homogeneous oxidation of the volatiles including both hydrocarbon and volatile-nitrogen components (NH{sub 3}, HCN). Heterogeneous char combustion to CO and CO{sub 2}, and char-nitrogen conversion to NO, N{sub 2}O, and N{sub 2} are described by a single particle model that includes 15 reaction steps given in the form of 6 net reaction paths. In the paper, the model is briefly described. A special emphasis is put on the evaluation of chemistry submodels. Modeling results on nitrogen oxides' formation are compared with measured concentration profiles in a 12 MW CFBC riser from literature. The importance of accurate chemistry description on predictions is

  12. Characterization of fuels for atmospheric fluidized bed combustion

    SciTech Connect

    Daw, C.S. ); Rowley, D.R.; Perna, M.A. . Research Center); Stallings, J.W. ); Divilio, R.J. )

    1990-01-01

    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.

  13. Synthetic aggregate compositions derived from spent bed materials from fluidized bed combustion and fly ash

    DOEpatents

    Boyle, Michael J.

    1994-01-01

    Cementitious compositions useful as lightweight aggregates are formed from a blend of spent bed material from fluidized bed combustion and fly ash. The proportions of the blend are chosen so that ensuing reactions eliminate undesirable constituents. The blend is then mixed with water and formed into a shaped article. The shaped article is preferably either a pellet or a "brick" shape that is later crushed. The shaped articles are cured at ambient temperature while saturated with water. It has been found that if used sufficiently, the resulting aggregate will exhibit minimal dimensional change over time. The aggregate can be certified by also forming standardized test shapes, e.g., cylinders while forming the shaped articles and measuring the properties of the test shapes using standardized techniques including X-ray diffraction.

  14. Fluidized bed combustion of solid organic wastes and low-grade coals: Research and modeling

    SciTech Connect

    Borodulya, V.A.; Dikalenko, V.I.; Palchonok, G.I.; Stanchits, L.K.

    1995-12-31

    Experimental studies were carried out to investigate devolatilization and combustion of single spherical particles of wood, hydrolytic lignin from ethanol production, leather processing sewage sludge, and low-grade Belarusian brown coals in a fluidized bed of sand. A two-phase model of fluidized bed combustion of biowaste is proposed. The model takes into account combustion of both volatiles and char in the bed as well as in the freeboard. Experimentally obtained characteristics of devolatilization and char combustion are used as parameters of the model proposed.

  15. Effect of ash content on the combustion process of simulated MSW in the fixed bed.

    PubMed

    Sun, Rui; Ismail, Tamer M; Ren, Xiaohan; Abd El-Salam, M

    2016-02-01

    This paper experimentally and numerically investigates the effects of ash content on the combustion process of simulated Municipal Solid Waste (MSW). A fixed-bed experimental reactor was utilized to reveal the combustion characteristics. Temperature distributions, ignition front velocity, and the characteristics of gas species' release were measured and simulated during the combustion process. In the present work, the two-dimensional unsteady mathematical heterogeneous model was developed to simulate the combustion process in the bed, including the process rate model as well as NOx production model. The simulation results in the bed are accordant with the experimental results. The results show that as ash content increases, the lower burning rate of fuel results in char particles leaving the grate without being fully burned, causing a loss of combustible material in the MSW in a fixed bed and therefore reducing the combustion efficiency and increasing the burning time of the MSW. PMID:26476592

  16. Development of second-generation pressurized fluidized bed combustion process

    SciTech Connect

    Wolowodiuk, W.; Robertson, A.; Bonk, D.

    1995-12-01

    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.

  17. Cyclone performance estimates for pressurized fluidized-bed combustion

    SciTech Connect

    Henry, R.F.; Podolski, W.F.

    1981-07-01

    Hot pressurized flue gas from pressurized fluidized-bed combustion must be cleaned up prior to its expansion in a gas turbine as part of the combined-cycle electric power generation concept. The performance of conventional cyclones in experimental tests has been compared with theory, with reasonable agreement. Prediction of the performance of a larger cyclone system shows that three stages should provide the cleanup required on the basis of current estimates of turbine tolerance of particulate matter. Advances in hot gas cleanup - optimized cyclones, augmented cyclones, and alternative devices - should provide future improvement in cycle efficiencies and costs, but simple cyclones are planned for first-generation PFB/CC pilot and demonstration plants.

  18. METAL FILTERS FOR PRESSURIZED FLUID BED COMBUSTION (PFBC) APPLICATIONS

    SciTech Connect

    M.A. Alvin

    2004-01-02

    Advanced coal and biomass-based gas turbine power generation technologies (IGCC, PFBC, PCFBC, and Hipps) are currently under development and demonstration. Efforts at the Siemens Westinghouse Power Corporation (SWPC) have been focused on the development and demonstration of hot gas filter systems as an enabling technology for power generation. As part of the demonstration effort, SWPC has been actively involved in the development of advanced filter materials and component configuration, has participated in numerous surveillance programs characterizing the material properties and microstructure of field-tested filter elements, and has undertaken extended, accelerated filter life testing programs. This report reviews SWPC's material and component assessment efforts, identifying the performance, stability, and life of porous commercial metal, advanced alloy, and intermetallic filters under simulated, pressurized fluidized-bed combustion (PFBC) conditions.

  19. Technical evaluation: pressurized fluidized-bed combustion technology

    SciTech Connect

    Miller, S A; Vogel, G J; Gehl, S M; Hanway, Jr, J E; Henry, R F; Parker, K M; Smyk, E B; Swift, W M; Podolski, W F

    1982-04-01

    The technology of pressurized fluidized-bed combustion, particularly in its application to a coal-burning combined-cycle plant, is evaluated by examining the technical status of advanced-concept plant components - boiler system (combustor, air-handling and air-injection equipment, and heat exchangers); solids handling, injection, and ejection system; hot-gas cleanup equipment; instrumentation/control system; and the gas turbine - along with materials of plant construction. Environmental performance as well as energy efficiency are examined, and economic considerations are reviewed briefly. The evaluation concludes with a broad survey of the principal related research and development programs in the United States and other countries, a foreview of the most likely technological developments, and a summary of unresolved technical issues and problems.

  20. Modern fluidized bed combustion in Ostrava-Karvina cogeneration plants

    SciTech Connect

    Mazac, V.; Novacek, A.; Volny, J.

    1995-12-01

    The contemporary situation of our environment claims the sensitive approach to solving effective conversion of energy. Limited supplies of noble fuels and their prices evoke the need to use new combustion technologies of accessible fuels in given region without negative ecological influences. Energoproject participates in the preparation of the two projects in Ostrava-Karvin{acute a} black coal field in Czech Republic. The most effective usage of fuel energy is the combined of electricity and heat. If this physical principle is supported by a pressurized fluidized bed combustion (PFBC) one obtains a high electricity/heat ratio integrated steam-gas cycle on the basis of solid fuel. Cogeneration plant Toebovice is the dominant source (600 MW{sub th}) of Ostrava district heating system (1100 MW{sub th}). The high utilization of the installed output and utilization of the clean, compact and efficient of the PFBC technology is the principal but not the single reason for the selection of the Toebovice power plant as the first cogeneration plant for installation of the PFBC in Czech Republic. The boiler will burn black coal from the neighboring coal basin.

  1. Atmospheric Fluidized Bed Combustion testing of North Dakota lignite

    SciTech Connect

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

    1980-05-01

    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.

  2. 10 CFR 503.10 - Use of fluidized bed combustion not feasible-general requirement for permanent exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Use of fluidized bed combustion not feasible-general... FUELS NEW FACILITIES General Requirements for Exemptions § 503.10 Use of fluidized bed combustion not... finds on a site-specific or generic basis that use of a method of fluidized bed combustion of...

  3. A CFD model for biomass combustion in a packed bed furnace

    NASA Astrophysics Data System (ADS)

    Karim, Md. Rezwanul; Ovi, Ifat Rabbil Qudrat; Naser, Jamal

    2016-07-01

    Climate change has now become an important issue which is affecting environment and people around the world. Global warming is the main reason of climate change which is increasing day by day due to the growing demand of energy in developed countries. Use of renewable energy is now an established technique to decrease the adverse effect of global warming. Biomass is a widely accessible renewable energy source which reduces CO2 emissions for producing thermal energy or electricity. But the combustion of biomass is complex due its large variations and physical structures. Packed bed or fixed bed combustion is the most common method for the energy conversion of biomass. Experimental investigation of packed bed biomass combustion is difficult as the data collection inside the bed is challenging. CFD simulation of these combustion systems can be helpful to investigate different operational conditions and to evaluate the local values inside the investigation area. Available CFD codes can model the gas phase combustion but it can't model the solid phase of biomass conversion. In this work, a complete three-dimensional CFD model is presented for numerical investigation of packed bed biomass combustion. The model describes the solid phase along with the interface between solid and gas phase. It also includes the bed shrinkage due to the continuous movement of the bed during solid fuel combustion. Several variables are employed to represent different parameters of solid mass. Packed bed is considered as a porous bed and User Defined Functions (UDFs) platform is used to introduce solid phase user defined variables in the CFD. Modified standard discrete transfer radiation method (DTRM) is applied to model the radiation heat transfer. Preliminary results of gas phase velocity and pressure drop over packed bed have been shown. The model can be useful for investigation of movement of the packed bed during solid fuel combustion.

  4. Fluidized-bed combustion process evaluation and program support. Quarterly report, October-December 1979

    SciTech Connect

    Johnson, I.; Podolski, W.F.; Henry, R.F.; Hanway, J.E.; Griggs, K.E.; Carls, E.L.; Jonke, A.A.

    1980-01-01

    Argonne National Laboratory is undertaking several tasks primarily in support of the pressurized fluidized-bed combustion (PFBC) project management team at Morgantown Energy Technology Center (METC). The Experimental Program Director of the International Energy Agency pressurized fluidized-bed combustion project was selected. Work is under way to provide fluidized-bed combustion process evaluation and program support to METC, including development of a planning methodology for PFBC technology development, determination of the state of the art of instrumentation for FBC applications, and evaluation of the performance capability of cyclones for hot-gas cleaning in PFBC systems.

  5. LABORATORY FEASIBILITY STUDIES FOR THE FLUIDIZED-BED COMBUSTION OF SPENT POTLINING FROM ALUMINUM REDUCTION

    EPA Science Inventory

    The report gives results of a preliminary assessment of the technical feasibility and environmental acceptability of a fluidized-bed combustion (FBC) process for the disposal of spent potlining waste from the aluminum reduction process. Technical efforts included: (1) differentia...

  6. Fluidized-bed combustion process evaluation and program support. Quarterly report, January-March 1980

    SciTech Connect

    Johnson, I.; Podolski, W.F.; Swift, W.M.; Henry, R.F.; Hanway, J.E.; Griggs, K.E.; Herzenberg, C.; Helt, J.E.; Carls, E.L.

    1980-12-01

    Argonne National Laboratory is undertaking several tasks primarily in support of the pressurized fluidized-bed combustion project management team at Morgantown Energy Technology Center. Work is under way to provide fluidized-bed combustion process evaluation and program support to METC, determination of the state of the art of instrumentation for FBC applications, evaluation of the performance capability of cyclones for hot-gas cleaning in PFBC systems, and an initial assessment of methods for the measurement of sodium sulfate dew point.

  7. Fluidized bed combustion of low-grade coal and wastes: Research and development

    SciTech Connect

    Borodulya, V.A.; Dikalenko, V.I.; Palchonok, G.I.; Vinogradov, L.M.; Dobkin, S.M.; Telegin, E.M.

    1994-12-31

    Experimental studies were carried out to investigate devolatilization of fuel as single spherical particles of wood, hydrolytic lignin, leather sewage sludge and Belarussian brown coals in a fluidized bed of sand. It is found that the devolatilization process depends on moisture and ash contents in fuel and on the external heat and mass transfer rate. The char combustion occurs largely in the intermediate region. Kinetic parameters of the devolatilization and char combustion are obtained. A low-capacity fluidized bed boiler suitable for combustion of coal and different wastes is described.

  8. Effect of the size distribution of coal on fluidized-bed combustion

    SciTech Connect

    Hirama, T.; Hosoda, H.; Nishizaki, H.; Chiba, T.; Kobayashi, H.

    1984-07-01

    To study the effect of the particle-size distribution on its combustion characteristics, coal was burned in a 0.25 m-square fluidized-bed combustor with a 3-m freeboard. A higher fines content increased the loss of unburned coal by elutriation, but reduced the loss from overflow from the bed surface. The overall combustion efficiency varied only slightly with the size distribution; the efficiency of combustion within the bed was reduced, but more combustion took place in the freeboard, both for 9.5-25 mm particles, owing to segregation in the bed, and for <2 mm particles, owing to elutriation. NO/SUB/x emission for two-stage combustion with these two size ranges was considerably higher than for particles within the broader range <25 mm. Since segregation of coarse particles and elutriation of unburned finer particles increase NO/SUB/x emission and reduced the bed combustion efficiency, it is desirable to use coal with a broad particle-size distribution.

  9. Numerical simulation of gas concentration and dioxin formation for MSW combustion in a fixed bed.

    PubMed

    Sun, Rui; Ismail, Tamer M; Ren, Xiaohan; Abd El-Salam, M

    2015-07-01

    A numerical model was employed to simulate the combustion process in a fixed porous bed of municipal solid waste (MSW). Mass, momentum, energy and species conservation equations of the waste bed were set up to describe the incineration process. The rate of moisture evaporation, volatile matter devolatilization, char combustion, NOx production, and reduction and dioxin formation were calculated and established according to the local thermal conditions and waste property characteristics. Changes in the bed volume during incineration were calculated according to the reaction rate of the process. The simulation results were compared with experimental data, which shows that the incineration process of waste in the fixed bed was reasonably simulated. The simulation results of weight loss and solid temperature in the bed agree with the experimental data, which shows that the waste combustion rate is nearly constant in the middle of the incineration process, and that moisture evaporation takes up most of the time for the overall incineration experiment. The emission of gas species from the bed surface is also agreeably simulated, with O2, CO2, and CO concentrations in flue gas agreeing with the experimental data. The simulation results benefit the understanding of the combustion process in the waste bed as well as the design of incinerator grates. PMID:25897505

  10. Volatiles combustion in fluidized beds. Final technical report, 4 September 1992--4 June 1995

    SciTech Connect

    Pendergrass, R.A. II; Raffensperger, C.; Hesketh, R.P.

    1996-02-29

    The goal of this project is to investigate the conditions in which volatiles will burn within both the dense and freeboard regions of fluidized beds. Experiments using a fluidized bed operated at incipient fluidization are being conducted to characterize the effect of particle surface area, initial fuel concentration, and particle type on the inhibition of volatiles within a fluidized bed. A review of the work conducted under this grant is presented in this Final Technical Report. Both experimental and theoretical work have been conducted to examine the inhibition of the combustion by the fluidized bed material, sand. It has been shown that particulate phase at incipient fluidization inhibits the combustion of propane by free radical destruction at the surface of sand particles within the particulate phase. The implications of these findings is that at bed temperatures lower than the critical temperatures, gas combustion can only occur in the bubble phase or at the top surface of a bubbling fluidized bed. In modeling fluidized bed combustion this inhibition by the particulate phase should be included.

  11. Co-combustion of tannery sludge in a commercial circulating fluidized bed boiler.

    PubMed

    Dong, Hao; Jiang, Xuguang; Lv, Guojun; Chi, Yong; Yan, Jianhua

    2015-12-01

    Co-combusting hazardous wastes in existing fluidized bed combustors is an alternative to hazardous waste treatment facilities, in shortage in China. Tannery sludge is a kind of hazardous waste, considered fit for co-combusting with coal in fluidized bedboilers. In this work, co-combustion tests of tannery sludge and bituminous coal were conducted in a power plant in Jiaxing, Zhejiang province. Before that, the combustion behavior of tannery sludge and bituminous were studied by thermogravimetric analysis. Tannery sludge presented higher reactivity than bituminous coal. During the co-combustion tests, the emissions of harmful gases were monitored. The results showed that the pollutant emissions met the Chinese standard except for NOx. The Concentrations of seven trace elements (As, Cr, Cd, Ni, Cu, Pb, Mn) in three exit ash flows (bottom ash in bed, fly ash in filter, and submicrometer aerosol in flue gas) were analyzed. The results of mono-combustion of bituminous coal were compared with those of co-combustion with tannery sludge. It was found that chromium enriched in fly ash. At last, the leachability of fly ash and bottom ash was analyzed. The results showed that most species were almost equal to or below the limits except for As in bottom ashes and Cr in the fly ash of co-combustion test. The concentrations of Cr in leachates of co-combustion ashes are markedly higher than that of coal mono-combustion ashes. PMID:26278370

  12. INVESTIGATION OF FLUID BED COMBUSTION OF MUNICIPAL SOLID WASTE

    EPA Science Inventory

    An experimental study was undertaken to burn processed municipal solid waste in a fluid-bed combustor containing water-cooled tubes in the bed. The 300-hour test was performed without incident and terminated on schedule. The combustor and ducting were clean on inspection after th...

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

    SciTech Connect

    Gulyurtlu, I.; Lopes, M.H.; Abelha, P.; Cabrita, I.; Oliveira, J.F.S.

    2006-06-15

    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.

  14. Understanding the behavior of Australian black coals in pressurized fluidized bed combustion

    SciTech Connect

    Stubington, J.F.; Wang, A.L.T.; Cui, Y.

    1999-07-01

    Ultimately, this study aims to predict the coal combustion efficiency in an industrial pressurized fluidized bed combustor (PFBC) for Australian black coals. This combustion efficiency depends predominantly upon the rate of elutriation of fine carbon particles, which is proportional to bed carbon loading in atmospheric experiments. The bed carbon loading is, in turn, dependent upon the rate of combustion of char particles within the PFBC. A novel batch-fed reactor has been designed, constructed and commissioned to enable separation and study of the mechanisms of coal devolatilization, char combustion and fine carbon particle elutriation in a PFBC and extraction of coal-specific parameters to describe these processes. The attrition and char combustion rates can only be determined experimentally and it is essential to match the environment around each coal particle, so that the results may be translated to the industrial scale. Therefore, the rig was designed for identical conditions of pressure, temperature, particle size and fluidizing velocity within the bed to those used industrially. The exhaust gas is analyzed continuously for oxygen, carbon dioxide, carbon monoxide and hydrocarbons as a function of time after coal injection, allowing separation and identification of the devolatilization and char combustion stages as well as measurement of the combustion rates. The elutriated carbon particles undergo minimal freeboard combustion and are collected in a cyclone and an in-line filter over any period of time during the experiment, for subsequent analysis. The sand bed containing the rig for collection and characterization of the partially burnt char particles. The rig is mostly computer-controlled and the design was subjected to a hazards analysis before construction. Results from the rig will be used in a mathematical model to predict the performance of the coals in industrial-scale PFBC.

  15. Co-combustion of textile residues with cardboard and waste wood in a packed bed

    SciTech Connect

    Ryu, Changkook; Phan, Anh N; Sharifi, Vida N; Swithenbank, Jim

    2007-11-15

    The combustible fraction of the municipal waste is mostly bio-derived. Energy recovery of the wastes that cannot be economically recycled is a key part of sustainable energy policy and waste management. Textile residues have high energy content. When burned alone in a packed bed system, however, their combustion efficiency is low due to the irregular propagation of the ignition front and the low burning rates. In order to achieve more efficient combustion of textile residues, a series of co-combustion tests were carried out for various mixture compositions and air flow rates in a packed bed combustor. The combustion performance of these materials was evaluated by using quantitative measures such as ignition rate, burning rate and equivalence ratio. Co-combustion of textile residues with cardboard for a textile fraction of up to 30% achieved satisfactorily high burning rate and low unburned carbon content in the bottom ash. The mixture was more resistant to convective cooling by air, which significantly expanded the range of air flow rate for combustion at high burning rates. In co-combustion with a material that has a very low ignition front speed such as waste wood, the propagation of the ignition front was governed by textile residues. Therefore, the co-combustion of textile residues can be better performed with a material having similar ignition front speeds, in which the two materials simultaneously burn at the ignition front. (author)

  16. EERC pilot-scale CFBC evaluation facility Project CFB test results

    SciTech Connect

    Mann, M.D.; Hajicek, D.R.; Henderson, A.K.; Moe, T.A.

    1992-09-01

    Project CFB was initiated at the University of North Dakota Energy and Environmental Research Center (EERC) in May 1988. Specific goals of the project were to (1) construct a circulating fluidized-bed combustor (CFBC) facility representative of the major boiler vendors' designs with the capability of producing scalable data, (2) develop a database for use in making future evaluations of CFBC technology, and (3) provide a facility for evaluating fuels, free of vendor bias for use in the - energy industry. Five coals were test-burned in the 1-MWth unit: North Dakota and Asian lignites, a Wyoming subbituminous, and Colorado and Pennsylvania bituminous coats. A total of 54 steady-state test periods were conducted, with the key test parameters being the average combustor temperature, excess air, superficial gas velocity, calcium-to-sulfur molar ratio, and the primary air-to-secondary air split. The capture for a coal fired in a CFBC is primarily dependent upon the total alkali-to-sulfur ratio. The required alkali-to ratio for 90% sulfur retention ranged from 1.4 to 4.9, depending upon coal type. While an alkali-to-ratio of 4.9 was required to meet 90% sulfur retention for the Salt Creek coal versus 1.4 for the Asian lignite, the total amount of sorbent addition required is much less for the Salt Creek coal, 4.2 pound sorbent per million Btu coal input, versus 62 pound/million Btu for the Asian lignite. The bituminous coals tested show optimal capture at combustor temperatures of approximately 1550[degree]F, with low-rank coals having optimal sulfur capture approximately 100[degree]F lower.

  17. Analysis of atmospheric fluidized bed combustion agglomerates. Final report

    SciTech Connect

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

    1984-04-01

    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.

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

    SciTech Connect

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

    1981-02-01

    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.

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

    PubMed

    You, Changfu; Xu, Xuchang

    2008-04-01

    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

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

    SciTech Connect

    Changfu You; Xuchang Xu

    2008-04-01

    Ventilation air methane (VAM) accounts for 60-80% of the total emissions from underground 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. 17 refs., 3 figs., 1 tab.

  1. Exploratory and basic fluidized-bed combustion studies. Quarterly report, January-March 1980

    SciTech Connect

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

    1980-12-01

    This work supports 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 particulates and alkali metal compounds from the flue gas, control of SO/sub 2/ and trace pollutants emissions, and other aspects of fluidized-bed combustion. This report presents information on: (1) the development of a limestone utilization predictive methodology, (2) studies of particle breakup and elutriation, (3) basic studies on limestone sulfation enhancement by hydration, (4) studies of the kinetics of the hydration process, and (5) an investigation of various hydration process concepts.

  2. A fixed granular-bed sorber for measurement and control of alkali vapors in PFBC (pressurized fluidized-bed combustion)

    SciTech Connect

    Lee, S.H.D.; Swift, W.M.

    1990-01-01

    Alkali vapors (Na and K) in the hot flue gas from the pressurized fluidized-bed combustion (PFBC) of coal could cause corrosion problems with the gas turbine blades. In a laboratory-scale PFBC test with Beulah lignite, a fixed granular bed of activated bauxite sorbent was used to demonstrate its capability for measuring and controlling alkali vapors in the PFBC flue gas. The Beulah lignite was combusted in a bed of Tymochtee dolomite at bed temperatures ranging from 850 to 875{degrees}C and a system pressure of 9.2 atm absolute. The time-averaged concentration of sodium vapor in the PFBC flue gas was determined from the analysis of two identical beds of activated bauxite and found to be 1.42 and 1.50 ppmW. The potassium vapor concentration was determined to be 0.10 ppmW. The sodium material balance showed that only 0.24% of the total sodium in the lignite was released as vapor species in the PFBC flue gas. This results in an average of 1.56 ppmW alkali vapors in the PFBC flue gas. This average is more than 1.5 orders of magnitude greater than the currently suggested alkali specification limit of 0.024 ppm for an industrial gas turbine. The adsorption data obtained with the activated bauxite beds were also analyzed mathematically by use of a LUB (length of unused bed)/equilibrium section concept. Analytical results showed that the length of the bed, L{sub o} in centimeters, relates to the break through time, {theta}{sub b} in hours, for the alkali vapor to break through the bed as follows: L{sub o} = 33.02 + 1.99 {theta}{sub b}. This formula provides useful information for the engineering design of fixed-bed activated bauxite sorbers for the measurement and control of alkali vapors in PFBC flue gas. 26 refs., 4 figs., 4 tabs.

  3. Pressurized fluidized-bed combustion part-load behavior. Volume I. Summary report

    SciTech Connect

    Roberts, A. G.; Pillai, K. K.; Raven, P.; Wood, P.

    1981-09-01

    Tests performed during 1980 to determine the part-load characteristics of a pressurized fluidized-bed combustor for a combined-cycle power plant and to examine its behavior during load changing are discussed. Part-load operation was achieved by varying the bed temperature by amounts between 200 to 300/sup 0/F and the bed depth from between 9 and 10 ft at rates varying between 0.2 ft/min and 0.5 ft/min. The performance at part-load steady-state conditions and during transient conditions is reported with information on combustion efficiency (99% at full-load with 9 ft bed depth and 1650/sup 0/F bed temperature; 95% with 4 ft depth and 1390/sup 0/F); sulfur retention (95/sup 0/ at full load to 80% at low bed depth and low bed temperature); sulfur emissions (no definitive results); NO/sub x/ emissions (tendency for increase as bed temperature was reduced); alkali emissions (no bed temperature effect detected); and heat transfer. It was demonstrated that load can be altered in a rapid and controlled manner by changing combinations of bed depth temperature and pressure. The most important practical change was the reduction in O/sub 2/ concentration which occurred when the bed height was increased at a rapid rate. The extra energy required to reheat the incoming bed material resulted (in the most extreme case) in a temporary drop in excess air from 65% to 12%. In a full-scale plant the loss of heat from the stored bed material would be much lower and the excess air trough when increasing load would not be as pronounced. Nevertheless, it seems prudent to design full-scale plant for a full load excess air of not less than about 50% when using bed depth as a load control parameter.

  4. Technical advances and new opportunities for fluidized bed combustion

    SciTech Connect

    Alliston, M.G.; Kokko, A.; Martin, B.G.; Olofsson, J.

    1997-12-31

    This paper outlines opportunities for new circulating fluidized bed (CFB) boilers, technical considerations in selecting a fluidized bed boiler, and CFB boiler configuration types and sizes. New opportunities for CFBs include fuel opportunities from coke, mine mouth coals, and waste products, and boiler application opportunities in industrial cogeneration, repowering, and developing nations. Technical considerations discussed for boiler selection are fuel flexibility and environmental aspects. Three boiler configurations are briefly described: (1) water-cooled cyclone with water-cooled loopseal, (2) integral cylindrical cyclone and loopseal, and (3) Cylindrical multi-inlet cyclone. CFB scale-up is also briefly discussed. 3 refs., 3 figs.

  5. Three dimensional dynamic simulation for bubbling pressurized fluidized bed combustion furnace

    SciTech Connect

    Itami, Teturo; Yoshioka, Susumu; Katori, Takanori; Oki, Katsuya; Sakata, Taro

    1995-12-31

    A mathematical model for the simulation of the pressurized fluidized bed combustion (PFBC) furnaces has been developed to predict three-dimensional distribution of fuel, oxygen and bed temperatures. In this model fuel particles in the bed have been considered as moving diffusively. Three different values of dispersion coefficients of fuel particles, two lateral and one axial coefficients, have been measured using the temperature profile obtained in the scale-down cold model. The model was designed according to the similarity rule, and features a tube-bundle arrangement in the bed. Some of the fuel particles on the bed surface are assumed in the model to be blown out from the bed, and are regarded as unburnt fuel. The ratio of such unburnt fuel particles to the fuel particles concentrated on the bed surface has been estimated using combustion efficiency data obtained in the pilot plant. These dispersion coefficients and the ratio of the unburnt fuel have been used in the proposed simulation model. For the design of the large scale PFBC plants, the present simulation model has been utilized. The number and the location of the fuel feed points have been optimized by taking uniformity of combustion as the design criteria. The criterion for estimating favorable features of combustion has been chosen as minimizing the quantity of unburnt fuel that would move in the freeboard and the high temperature gas line. This paper presents the description and the verification of the proposed model and its application to the furnace design of the large scale PFBC plant.

  6. INFLUENCE OF BED-REGION STOICHIOMETRY ON NITRIC OXIDE FORMATION IN FIXED-BED COAL COMBUSTION

    EPA Science Inventory

    The article describes the use of a 15.3 x 25.4 cm thick bed reactor with refractory walls to investigate the influence of bed-region (first-stage) stoichiometry on fuel nitrogen evolution and reaction in coal-fired mass-burning stokers. The combustor operated in a batch mode prov...

  7. EVALUATION OF TRACE ELEMENT RELEASE FROM FLUIDIZED-BED COMBUSTION SYSTEMS

    EPA Science Inventory

    The report gives results of an investigation of four trace elements: lead, beryllium, mercury, and fluorine. The chemical fate of minor and trace elements is important in assessing the environmental impact of the fluidized-bed combustion (FBC) process and, for certain elements, i...

  8. CERAMIC FILTER TESTS AT THE EPA/EXXON PFBC (PRESSURIZED FLUIDIZED BED COAL COMBUSTION) MINIPLANT

    EPA Science Inventory

    The paper describes the performance of the Acurex ceramic bag filter operating at temperatures up to 880C and pressures up to 930 kPa on particulate-laden flue gas from a pressurized fluidized-bed coal combustion (PFBC) unit on a slipstream of gas taken after the second stage cyc...

  9. PARTICULATE EMISSIONS AND CONTROL IN FLUIDIZED-BED COMBUSTION: MODELING AND PARAMETRIC PERFORMANCE

    EPA Science Inventory

    The report discusses a model, developed to describe the physical characteristics of the particulates emitted from fluidized-bed combustion (FBC) systems and to evaluate data on FBC particulate control systems. The model, which describes the particulate emissions profile from FBC,...

  10. 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 ...

  11. UTILITY BOILER DESIGN/COST COMPARISON: FLUIDIZED-BED COMBUSTION VS. FLUE GAS DESULFURIZATION

    EPA Science Inventory

    The report gives results of a conceptual design, performance, and cost comparison of utility scale (750-925 MWe) coal-burning power plants employing three alternative technologies: conventional boiler with a stack gas scrubber (CWS), atmospheric-pressure fluidized-bed combustion ...

  12. 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...

  13. Materials performance in coal-fired fluidized-bed combustion environments

    SciTech Connect

    Natesan, K.

    1993-07-01

    Development of cogeneration systems that involve combustion of coal in a fluidized bed for the generation of electricity and process heat has been in progress for a number of years. This paper addresses some of the key components in these systems, materials requirements/performance, and areas where additional effort is needed to improve the viability of these concepts for electric power generation.

  14. Investigation of heat transfer and combustion in the advanced fluidized bed combustor (FBC)

    SciTech Connect

    Dr. Seong W. Lee

    1998-10-01

    The objective of this project is to predict the heat transfer and combustion performance in newly-designed fluidized bed combustor (FBC) and to provide the design guide lines and innovative concept for small-scale boiler and furnace. The major accomplishments are summarized.

  15. PILOT-SCALE ASSESSMENT OF CONVENTIONAL PARTICULATE CONTROL TECHNOLOGY FOR PRESSURIZED FLUIDIZED-BED COMBUSTION EMISSIONS

    EPA Science Inventory

    The report gives results of an evaluation of electrostatic precipitator (ESP) and fabric filter particulate control technology for the EPA/Exxon pressurized fluidized-bed combustion (PFBC) Miniplant in Linden, NJ. EPA's mobile ESP and fabric filter pilot facilities were slipstrea...

  16. QUALITY ASSURANCE OF FLUIDIZED-BED COMBUSTION (FBC) H2SO4 MEASUREMENTS

    EPA Science Inventory

    The report gives results of a study to: evaluate existing data on H2SO4 measurements from fluidized-bed combustion (FBC) processes; determine the true value of the H2SO4 concentration which might have been obtained had the control condensation (Goksoyr/Ross) procedure been used; ...

  17. Wood Combustion Behaviour in a Fixed Bed Combustor

    NASA Astrophysics Data System (ADS)

    Tokit, Ernie Mat; Aziz, Azhar Abdul; Ghazali, Normah Mohd

    2010-06-01

    Waste wood is used as feedstock for Universiti Teknologi Malaysia's newly-developed two-stage incinerator system. The research goals are to optimize the operation of the thermal system to the primary chamber, to improve its combustion efficiency and to minimize its pollutants formation. The combustion process is evaluated with the variation of fuel's moisture content. For optimum operating condition, where the gasification efficiency is 95.53%, the moisture content of the fuel is best set at 17%; giving outlet operating temperature of 550°C and exhaust gas concentrations with 1213 ppm of CO, 6% of CO2 and 14% of O2 respectively. In line to the experimental work, a computational fluid dynamics software, Fluent is used to simulate the performance of the primary chamber. Here the predicted optimum gasification efficiency stands at 95.49% with CO, CO2 and O2 concentrations as 1301 ppm, 6.5% and 13.5% respectively.

  18. Capture of toxic metals by vaious sorbents during fluidized bed coal combustion

    SciTech Connect

    Ho, T.C.; Ghebremeskel, A.; Hopper, J.R.

    1995-12-31

    This study investigated the potential of employing suitable sorbents to capture trace metallic substances during fluidized bed coal combustion. The objectives of the study were to demonstrate the capture process, identify effective sorbents, and characterize the capture efficiency. Experiments were carried out in a 25.4 mm (1 ``) quartz fluidized bed coal combustor enclosed in an electric furnace. In an experiment, a coal sample from the DOE Coal Sample Bank or the Illinois Basin Coal Sample Bank was burned in the bed with a sorbent under various combustion conditions and the amount of metal capture by the sorbent was determined. The metals involved in the study were arsenic, cadmium, lead, mercury and selenium, and the sorbents tested included bauxite, zeolite and lime. The combustion conditions examined included bed temperature, particle size, fluidization velocity (percent excess air), and sorbent bed height. In addition to the experimental investigations, potential metal-sorbent reactions were also identified through performing chemical equilibrium analyses based on the minimization of system free energy.

  19. Mathematical modelling of particle mixing effect on the combustion of municipal solid wastes in a packed-bed furnace.

    PubMed

    Yang, Yao Bin; Swithenbank, Jim

    2008-01-01

    Packed bed combustion is still the most common way to burn municipal solid wastes. In this paper, a dispersion model for particle mixing, mainly caused by the movement of the grate in a moving-burning bed, has been proposed and transport equations for the continuity, momentum, species, and energy conservation are described. Particle-mixing coefficients obtained from model tests range from 2.0x10(-6) to 3.0x10(-5)m2/s. A numerical solution is sought to simulate the combustion behaviour of a full-scale 12-tonne-per-h waste incineration furnace at different levels of bed mixing. It is found that an increase in mixing causes a slight delay in the bed ignition but greatly enhances the combustion processes during the main combustion period in the bed. A medium-level mixing produces a combustion profile that is positioned more at the central part of the combustion chamber, and any leftover combustible gases (mainly CO) enter directly into the most intensive turbulence area created by the opposing secondary-air jets and thus are consumed quickly. Generally, the specific arrangement of the impinging secondary-air jets dumps most of the non-uniformity in temperature and CO into the gas flow coming from the bed-top, while medium-level mixing results in the lowest CO emission at the furnace exit and the highest combustion efficiency in the bed. PMID:17697769

  20. Update of the Black Dog atmospheric fluidized bed combustion project

    SciTech Connect

    Osthus, D.; Larva, J.; Rens, D. )

    1988-01-01

    Northern States Power Co. converted its Black Dog Unit 2, a pulverized coal-fired 100 MW unit that was built in 1954, to an atmospheric fluidized bed (bubbling bed) configuration, in order to commercially demonstrate AFBC technology as a cost-effective way to reduce SO2 emissions. As part of the AFBC conversion, the unit was upgraded to 130 MW capacity. Unit 2 burns Western coal, is equipped with electrostatic precipitators, and cycles on and off line daily. The innovative nature of this project contributed to a protracted encountered. These problems are discussed. Many of the problems have been solved, and the unit is now meeting most of the goals set for the project.

  1. Proceedings of the sixth international conference on fluidized bed combustion. Volume II. Technical sessions

    SciTech Connect

    1980-08-01

    The Sixth International Conference on Fluidized Bed Combustion was held April 9-11, 1980, at the Atlanta Hilton, Atlanta, Georgia. It was sponsored by the US Department of Energy, the Electric Power Research Institute, the US Environmental Protection Agency, and the Tennessee Valley Authority. The papers covered recent developments in atmospheric and pressurized fluidized-bed combustion, especially the design, operation and control of pilot and demonstration plants. The cleanup of combustion products and the erosion, corrosion and fouling of gas turbines was emphasized also. Fifty-five papers from Volume 2 of the proceedings have been entered individually into EDB and ERA; five papers had been entered previously from other sources. (LTN)

  2. Effects of fluidized bed combustion residue on pecan seedling growth and nutrient content. [Carya illinoensis

    SciTech Connect

    Edwards, J.H.; White, A.W. Jr.; Bennett, O.L.

    1985-01-01

    Fluidized bed combustion residue from a calcitic limestone source (FBCRC), a by-product of scrubbing SO/sub 2/ from fossil fuel fired boilers using the FBC technique was evaluated as a source of calcium for pecan (Carya illinoensis (Wang.) K. Koch) seedlings. Fluidized bed combustion residue produced following injection of calcitic limestone into the combustion chamber was more effective in neutralizing soil acidity and increasing extractable soil Ca levels than agricultural calcitic limestone. The Ca concentration in the pecan leaves was increased linearly by Ca rates for both 12- and 24-week growth periods, but stem and petiole Ca concentration was increased linearly for the second 12-week growth period. Macronutrient concentrations were affected by Ca rates for both 12- and 24-week growth periods, but no effect was observed with Ca source. The primary difference was between the control and all other Ca rates.

  3. Lewis Pressurized, Fluidized-Bed Combustion Program. Data and Calculated Results

    NASA Technical Reports Server (NTRS)

    Rollbuhler, R. J.

    1982-01-01

    A 200 kilowatt (thermal), pressurized, fluidized bed (PFB) reactor and research test facility were designed, constructed, and operated. The facility was established to assess and evaluate the effect of PFB hot gas effluent on aircraft turbine engine materials that may have applications in stationary powerplant turbogenerators. The facility was intended for research and development work and was designed to operate over a wide range of conditions. These conditions included the type and rate of consumption of fuel (e.g., coal) and sulfur reacting sorbent material: the ratio of feed fuel to sorbent material; the ratio of feed fuel to combustion airflow; the depth of the fluidized reaction bed; the temperature and pressure in the reaction bed; and the type of test unit that was exposed to the combustion exhaust gases.

  4. Modeling of fluidized-bed combustion of coal: Phase II, final reports. Volume V. Appendix: stability and instability in fluidized-bed combustion

    SciTech Connect

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

    1980-10-01

    This document is the fifth of the seven volumes series of our Phase II Final Report. The material developed in this volume has not been incorporated into the system model. It will be used as a precursor of a transient model to be developed in the next phase of our model work. There have been various fluidized combustor models of differing complexity and scope published in the literature. Most of these models have identified and predicted - often in satisfactory agreement with results from pilot units - the key steady state combustor characteristics such as the mass of carbon in the bed (carbon loading), the combustion efficiency, the sulfur retention by the solid sorbent and the pollutant (mainly NO/sub x/) emissions. These models, however, cannot be in most instances successfully used to study the extinction and ignition characteristics of the combustor because they are isothermal in structure in the sense that the bed temperature is not an output variable but rather an input one and must be a priori specified. In order to remedy these inadequacies of the previous models, we here present a comprehensive account of the formulation and some typical results of a new nonisothermal model which has been developed in order to study, among other things, the ignition and extinction characteristics of the AFBC units. This model is able to predict the temperature patterns in the bed, the carbon loading, the combustion efficiency and the O/sub 2/ and CO concentration profiles in the combustor for the different design or operational characteristics.

  5. Mathematical model for the continuous combustion of char particles in a fluidized bed

    SciTech Connect

    Saxena, S.C.; Rehmat, A.

    1980-12-01

    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.

  6. Combustion characteristics of spent catalyst and paper sludge in an internally circulating fluidized-bed combustor.

    PubMed

    Roh, Seon Ah; Jung, Dae Sung; Kim, Sang Done; Guy, Christophe

    2005-09-01

    Combustion of spent vacuum residue hydrodesulfurization catalyst and incineration of paper sludge were carried out in thermo-gravimetric analyzer and an internally circulating fluidized-bed (ICFB) reactor. From the thermo-gravimetric analyzer-differential thermo-gravimetric curves, the pre-exponential factors and activation energies are determined at the divided temperature regions, and the thermo-gravimetric analysis patterns can be predicted by the kinetic equations. The effects of bed temperature, gas velocity in the draft tube and annulus, solid circulation rate, and waste feed rate on combustion efficiency of the wastes have been determined in an ICFB from the experiments and the model studies. The ICFB combustor exhibits uniform temperature distribution along the bed height with high combustion efficiency (>90%). The combustion efficiency increases with increasing reaction temperature, gas velocity in the annulus region, and solid circulation rate and decreases with increasing waste feed rate and gas velocity in the draft tube. The simulated data from the kinetic equation and the hydrodynamic models predict the experimental data reasonably well. PMID:16259422

  7. Temporal measurements and kinetics of selenium release during coal combustion and gasification in a fluidized bed.

    PubMed

    Shen, Fenghua; Liu, Jing; Zhang, Zhen; Yang, Yingju

    2016-06-01

    The temporal release of selenium from coal during combustion and gasification in a fluidized bed was measured in situ by an on-line analysis system of trace elements in flue gas. The on-line analysis system is based on an inductively coupled plasma optical emission spectroscopy (ICP-OES), and can measure concentrations of trace elements in flue gas quantitatively and continuously. The results of on-line analysis suggest that the concentration of selenium in flue gas during coal gasification is higher than that during coal combustion. Based on the results of on-line analysis, a second-order kinetic law r(x)=0.94e(-26.58/RT)(-0.56 x(2) -0.51 x+1.05) was determined for selenium release during coal combustion, and r(x)=11.96e(-45.03/RT)(-0.53 x(2) -0.56 x+1.09) for selenium release during coal gasification. These two kinetic laws can predict respectively the temporal release of selenium during coal combustion and gasification with an acceptable accuracy. Thermodynamic calculations were conducted to predict selenium species during coal combustion and gasification. The speciation of selenium in flue gas during coal combustion differs from that during coal gasification, indicating that selenium volatilization is different. The gaseous selenium species can react with CaO during coal combustion, but it is not likely to interact with mineral during coal gasification. PMID:26897573

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

    SciTech Connect

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

    1980-09-01

    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.

  9. Meat and bone meal as secondary fuel in fluidized bed combustion

    SciTech Connect

    L. Fryda; K. Panopoulos; P. Vourliotis; E. Kakaras; E. Pavlidou

    2007-07-01

    Meat and Bone Meal (MBM) was co-fired in a laboratory scale fluidized bed combustion (FBC) apparatus with two coals. Several fuel blends were combusted under different conditions to study how primary fuel substitution by MBM affects flue gas emissions as well as fluidized bed (FB) agglomeration tendency. MBM, being a highly volatile fuel, caused significant increase of CO emissions and secondary air should be used in industrial scale applications to conform to regulations. The high N-content of MBM is moderately reflected on the increase of nitrogen oxides emissions which are reduced by MBM derived volatiles. The MBM ash, mainly containing bone material rich in Ca, did not create any noteworthy desulphurization effect. The observed slight decrease in SO{sub 2} emissions is predominantly attributed to the lower sulphur content in the coal/MBM fuel mixtures. The SEM/EDS analysis of bed material samples from the coal/MBM tests revealed the formation of agglomerates of bed material debris and ash with sizes that do not greatly exceed the original bed inventory and thus not problematic. 37 refs., 9 figs., 3 tabs.

  10. Method of removing sulfur emissions from a fluidized-bed combustion process

    DOEpatents

    Vogel, Gerhard John; Jonke, Albert A.; Snyder, Robert B.

    1978-01-01

    Alkali metal or alkaline earth metal oxides are impregnated within refractory support material such as alumina and introduced into a fluidized-bed process for the combustion of coal. Sulfur dioxide produced during combustion reacts with the metal oxide to form metal sulfates within the porous support material. The support material is removed from the process and the metal sulfate regenerated to metal oxide by chemical reduction. Suitable pore sizes are originally developed within the support material by heat-treating to accommodate both the sulfation and regeneration while still maintaining good particle strength.

  11. Industrial application of fluidized-bed combustion, Anthracite Culm Combustion Program, A/E Technical Management Services. Final report

    SciTech Connect

    Not Available

    1981-01-01

    The Energy Research and Development Administration (now DOE) initiated the $80,000,000 Fluidized Bed Combustion Programs in 1976 and contracts were awarded to five participants. Subsequently, in 1977 there were three additional contracts awarded for the Anthracite Culm Program. The objectives were to determine which applications were most feasible, and to design, build and operate demonstration plants with capacities of 25 to 100 million Btu per hour output burning high sulfur coals and other fuels to obtain sufficient data to enable industry to scale up to larger plant sized installations. Contributions of each of the participants are discussed. Relative merits of each design approach is covered. Specific areas such as fuel feed systems, grid plate design, ignition systems, fly ash reinjection systems, particulate clean up and control systems are discussed. Remaining areas of concern are errosion, combustion efficiency and reliability.

  12. Devolatilization and ash comminution of two different sewage sludges under fluidized bed combustion conditions

    SciTech Connect

    Solimene, R.; Urciuolo, M.; Cammarota, A.; Chirone, R.; Salatino, P.; Damonte, G.; Donati, C.; Puglisi, G.

    2010-04-15

    Two different wet sewage sludges have been characterized under fluidized bed combustion conditions with reference to their devolatilization behavior and ash comminution with the aid of different and complementary experimental protocols. Analysis of the devolatilization process allowed to determine the size of fuel particle able to achieve effective lateral spreading of the volatile matter across the cross-section of medium-scale combustors. Primary fragmentation and primary ash particle characterization pointed out the formation of a significant amount of relatively large fragments. The mechanical properties of these fragments have been characterized by means of elutriation/abrasion tests using both quartz and sludge ash beds. (author)

  13. Trace metal capture by various sorbents during fluidized bed coal combustion

    SciTech Connect

    Ho, T.C.; Ghebremeskel, A.; Hopper, J.R.

    1996-06-01

    Experiments were conducted in a 1-in. quartz fluidized bed combustor enclosed in an electric furnace. Coal samples were burned in the bed with a sorbent under specific combustion conditions and the amount of metal capture by the sorbent determined. Three different cao samples from the Illinois Basin Coal Sample Bank were tested. Metals involved were Cd, Pb, and Cr; the sorbents included bauxite, zeolite, and lime. Potential metal-sorbent reactions were identified. Results indicated that metal capture by sorbent can be as high as 96%, depending on the metal species and sorbent. All 3 sorbents were capable of capturing Pb, zeolite and lime were able to capture Cr, and bauxite was the only sorbent capable of capturing Cd. Thermodynamic equilibrium calculations suggested the formation of metal-sorbent compounds such as Pb{sub 2}SiO{sub 4}, CdAl{sub 2}O{sub 4}, and CdSiO{sub 3} solids under the combustion conditions.

  14. Trace metal capture by various sorbents during fluidized bed coal combustion

    SciTech Connect

    Ho, T.C.; Ghebremeskel, A.; Wang, K.S.; Hopper, J.R.

    1997-07-01

    This study investigated the potential of employing suitable sorbents to capture toxic trace metallic substances during fluidized bed coal combustion. Metal capture experiments were carried out in a 25.4 mm (1 inch) quartz fluidized bed combustor enclosed in an electric furnace. The metals involved were cadmium, lead, chromium, arsenic and selenium, and the sorbents tested included bauxite, zeolite and lime. In addition to the experimental investigations, potential metal-sorbent reactions were also identified through chemical equilibrium calculations based on the minimization of system free energy. The observed experimental results indicated that metal capture by sorbents can be as high as 88% depending on the metal species and sorbent involved. Results from thermodynamic equilibrium simulations suggested the formation of metal-sorbent compounds such as Pb{sub 2}SiO{sub 4}(s), CdAl{sub 2}O{sub 4}(s) and CdSiO{sub 3}(s) under the combustion conditions.

  15. Combustion Characteristics of Lignite Char in a Laboratory-scale Pressurized Fluidized Bed Combustor

    NASA Astrophysics Data System (ADS)

    Murakami, Takahiro; Suzuki, Yoshizo

    In a dual fluidized bed gasifier, the residual char after steam gasification is burnt in riser. The objectives of this work are to clarify the effect of parameters (temperature, pressure, and particle size of lignite char) of char combustion using a laboratory-scale pressurized fluidized bed combustor (PFBC). As a result, the burnout time of lignite char can be improved with increasing operating pressure, and temperature. In addition, the decrease in the particle size of char enhanced the effect on burnout time. The initial combustion rate of the char can be increased with increasing operating pressure. The effect was decreased with increasing operating temperature. However, the effect of operating pressure was slightly changed in small particle size, such as 0.5-1.0 mm. It takes about 20 sec to burn 50% of char in the operating pressure of 0.5 MPa and the particle size of 0.5-1.0 mm.

  16. Capture of alkali during pressurized fluidized-bed combustion using in-bed sorbents

    SciTech Connect

    Mann, M.D.; Ludlow, D.K.

    1997-12-31

    The primary focus of this research was the removal of alkali from PFBC flue gases to a level specified by turbine manufactures. The target level was less than 24 ppbw. Several of the aluminosilicate minerals have the potential to capture alkalis, especially sodium and potassium, under conditions typical of fluid-bed operation. Other goals of this work were to investigate the potential for simultaneously removing SO{sub 2} and Cl from the PFBC gas stream. The initial work focused primarily on one class of sorbents, sodalites, with the goal of determining whether sodalites can be used as an in-bed sorbent to simultaneously remove alkali and sulfur. Thermo gravimetric analysis (TGA) was used to study the mechanism of alkali capture using sodalite. Further testing was performed on a 7.6 cm (3-in.)-diameter pressurized fluid-bed reactor (PFBR). Early results indicated that simultaneous removal of alkali and sulfur and/or chlorine was not practical under the conditions for commercial PFBC operations. Therefore, the focus of the latter part of this work was on sorbents that have been shown to capture alkali in other systems. The effectiveness of bauxite and kaolinite to reduce vapor-phase alkali concentrations was determined. In addition to studying the gettering capability of the sorbent, the impact of the getter on operational performance was evaluated. This evaluation included examining potential agglomeration of bed particles, deposition on heat-transfer surfaces, and the bridging and blinding of ceramic candle filters. The focus of this paper is on the work performed on the PFBR.

  17. Proceedings of the sixth international conference on fluidized bed combustion. Volume III. Technical sessions

    SciTech Connect

    1980-08-01

    The Sixth International Conference on Fluidized Bed Combustion was held April 9-11, 1980, at the Atlanta Hilton, Atlanta, Georgia. It was sponsored by the US Department of Energy, the Electric Power Research Institute, the US Environmental Protection Agency, and the Tennessee Valley Authority. Forty-five papers from Vol. III of the proceedings have been entered individually into EDB and ERA. Two papers had been entered previously from other sources. (LTN)

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

    SciTech Connect

    Not Available

    1992-05-01

    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.

  19. Design and performance of a fluidized-bed incinerator for TRU combustible wastes

    SciTech Connect

    Meile, L.J.; Meyer, F.G.

    1982-01-01

    Problems encountered in the incineration of glovebox generated waste at Rocky Flats Plant (RFP) led to the development of a fluidized-bed incineration (FBI) system for transuranic (TRU) combustible wastes. Laboratory and pilot-scale testing of the process preceded the installation of an 82-kg/h production demonstration incinerator at RFP. The FBI process is discussed, and the design of the demonstration incinerator is described. Operating experience and process performance for both the pilot and demonstration units are presented.

  20. Fundamental Combustion Characteristics of Sewage Sludge in Fluidized Bed Incinerator with Turbocharger

    NASA Astrophysics Data System (ADS)

    Murakami, Takahiro; Suzuki, Yoshizo; Nagasawa, Hidekazu; Yamamoto, Takafumi; Koseki, Takami; Hirose, Hitoshi; Ochi, Shuichi

    An epoch-making incineration plant, which is equipped with a pressurized fluidized-bed combustor coupled to a turbocharger, for the recovery of the energy contained in sewage sludge is proposed. This plant has three main advantages. (1) A pressure vessel is unnecessary because the maximum operating pressure is 0.3 MPa (absolute pressure). The material cost for plant construction can be reduced. (2) CO2 emissions originating from power generation can be decreased because the FDF (Forced Draft Fan) and the IDF (Induced Draft Fan) are omitted. (3) Steam in the flue gas becomes a working fluid of the turbocharger, so that in addition to the combustion air, the surplus air is also generable. Therefore, this proposed plant will not only save energy but also the generate energy. The objective of this study is to elucidate the fundamental combustion characteristics of the sewage sludge using a lab-scale pressurized fluidized bed combustor (PFBC). The tested fuels are de-watered sludge and sawdust. The temperature distribution in the furnace and N2O emissions in the flue gas are experimentally clarified. As the results, for sludge only combustion, the temperature in the sand bed decreases by drying and pyrolysis, and the pyrolysis gas burns in the freeboard so that the temperature rises. On the other hand, the residual char of sawdust after pyrolysis burns stably in the sand bed for the co-firing of sludge and sawdust. Thus the temperature of the co-firing is considerably higher than that of the sludge only combustion. N2O emissions decreases with increasing freeboard temperature, and are controlled by the temperature for all experimental conditions. These data can be utilize to operation the demonstration plant.

  1. Proceedings of the Sixth International Conference on Fluidized Bed Combustion. Volume 1. Plenary sessions

    SciTech Connect

    1980-08-01

    The Sixth International Conference on Fluidized Bed Combustion was held at the Atlanta Hilton, Atlanta, Georgia, April 9-11, 1980. The papers in this volume involved presentation of the research and development programs of the US (US DOE, TVA, EPRI and US EPA), United Kingdom, Federal Republic of Germany and the People's Republic of China. Eight papers from Vol. 1 (Plenary Sessions) of the proceedings have been entered individually into EDB and ERA. (LTN)

  2. Abatement of N{sub 2}O emissions from circulating fluidized bed combustion through afterburning

    SciTech Connect

    Gustavsson, L.; Leckner, B.

    1995-04-01

    A method for the abatement of N{sub 2}O emission from fluidized bed combustion has been investigated. The method consists of burning a secondary fuel after the normal circulating fluidized bed combustor. Liquefied petroleum gas (LPG), fuel oil, pulverized coal, and wood, as well as sawdust, were used as the secondary fuel. Experiments showed that the N{sub 2}O emission can be reduced by 90% or more by this technique. The resulting N{sub 2}O emission was principally a function of the gas temperature achieved in the afterburner and independent of afterburning fuel, but the amount of air in the combustion gases from the primary combustion also influences the results. No negative effects on sulfur capture or on NO or CO emissions were recorded. In the experiments, the primary cyclone of the fluidized bed boiler was used for afterburning. If afterburning is implemented in a plant optimized for this purpose, an amount of secondary fuel corresponding to 10% of the total energy input should remove practically all N{sub 2}O. During the present experiments the secondary fuel consumption was greater than 10% of the total energy input due to various losses.

  3. Thermal decomposition of selected chlorinated hydrocarbons during gas combustion in fluidized bed

    PubMed Central

    2013-01-01

    Background The process of thermal decomposition of dichloromethane (DCM) and chlorobenzene (MCB) during the combustion in an inert, bubbling fluidized bed, supported by LPG as auxiliary fuel, have been studied. The concentration profiles of C6H5CI, CH2Cl2, CO2, CO, NOx, COCl2, CHCl3, CH3Cl, C2H2, C6H6, CH4 in the flue gases were specified versus mean bed temperature. Results The role of preheating of gaseous mixture in fluidized bed prior to its ignition inside bubbles was identified as important factor for increase the degree of conversion of DCM and MCB in low bed temperature, in comparison to similar process in the tubular reactor. Conclusions Taking into account possible combustion mechanisms, it was identified that autoignition in bubbles rather than flame propagation between bubbles is needed to achieve complete destruction of DCM and MCB. These condition occurs above 900°C causing the degree of conversion of chlorine compounds of 92-100%. PMID:23289764

  4. Hydration of spent limestone and dolomite to enhance sulfation in fluidized-bed combustion

    SciTech Connect

    Shearer, J.A.; Smith, G.W.; Moulton, D.S.; Turner, C.B.; Myles, K.M.; Johnson, I.

    1980-01-01

    The utilization of CaO in fluidized bed combustion can be markedly increased to reduce the cost and environmental impact of quarrying and disposing of large quantities of solid waste. A new method of treatment of spent bed material to reactivate its SO/sub 2/ capturing ability has been found. Partially sulfated spent overflow material from a fluidized-bed combustor is treated with water and then reintroduced to the combustor as renewed feed that further reacts with SO/sub 2/. This material has sufficient physical integrity, due to the outer layer of CaSO/sub 4/, and high reactivity to make it suitable as a sorbent feedstock. The work reported here details observations on a number of limestones and dolomites reacted in laboratory furnaces under simulated combustion conditions as well as verification of the effectiveness of the method in a 15-cm-ID process development unit scale atmospheric fluidized-bed coal combustor. Initial kinetic studies have also been made on the hydration reaction of partially sulfated limestone. A proposed mechanism of interaction is discussed to explain the enhanced reactivity. Changes in total porosity and pore size distribution in the partially sulfated material due to Ca(OH)/sub 2/ formation and its dehydration serve to open up the particle interior and its residual CaO to further reaction with SO/sub 2/. Almost complete utilization of the available CaO can be achieved by successive applications of this promising new technique.

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

    SciTech Connect

    Jack A. Fuller; Harvie Beavers; Robert Bessette

    2006-06-15

    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.

  6. Modeling of NOx emissions from fluidized bed combustion of high volatile lignites

    SciTech Connect

    Afacan, O.; Gogebakan, Y.; Selcuk, N.

    2007-01-15

    A comprehensive model, previously developed and tested for prediction of behavior of continuous fluidized bed combustors is extended to incorporate NOx formation and reduction reactions and applied to the simulation of Middle East Technical University (METU) 0.3 MW Atmospheric Bubbling Fluidized Bed Combustor (ABFBC) burning lignites with high Volatile Matter/Fixed Carbon (VM/FC) ratios in their own ashes. Favorable comparisons are obtained between the predicted and measured temperatures and concentrations of gaseous species along the combustor. Results show that determination of partitioning of coal nitrogen into char-N and volatile-N, char combustion rate, and amount of volatile nitrogen released along the combustor are found to be the most important parameters that affect NO formation and reduction in bubbling fluidized bed combustors.

  7. Experimental study on combustion characteristics and NOX emissions of pulverized anthracite preheated by circulating fluidized bed

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Zhu, Jian-Guo; Lu, Qing-Gang

    2011-08-01

    A 30 kW bench-scale rig of pulverized anthracite combustion preheated by a circulating fluidized bed (CFB) was developed. The CFB riser has a diameter of 90 mm and a height of 1,500 mm. The down-fired combustion chamber (DFCC) has a diameter of 260 mm and a height of 3,000 mm. Combustion experiments were carried out using pulverized anthracite with 6.74% volatile content. This low volatile coal is difficult to ignite and burn out. Therefore, it requires longer burnout time and higher combustion temperature, which results in larger NOX emissions. In the current study, important factors that influence the combustion characteristics and NOX emissions were investigated such as excess air ratio, air ratio in the reducing zone, and fuel residence time in the reducing zone. Pulverized anthracite can be quickly preheated up to 800°C in CFB when the primary air is 24% of theoretical air for combustion, and the temperature profile is uniform in DFCC. The combustion efficiency is 94.2%, which is competitive with other anthracite combustion technologies. When the excess air ratio ranges from 1.26 to 1.67, the coal-N conversion ratio is less than 32% and the NOX emission concentration is less than 371 mg/m3 (@6% O2). When the air ratio in the reducing zone is 0.12, the NOX concentration is 221 mg/m3 (@6% O2), and the coal-N conversion ratio is 21%, which is much lower than that of other boilers.

  8. A low emission technology -- low cost coal water mixture fired fluidized bed combustion

    SciTech Connect

    Jianhua Yan; Xuguang Jiang; Yong Chi

    1995-12-31

    In this paper, low cost coal water mixture (CWM) FBC technology is described. Low cost CWM may be coal washery sludge or the mixture of water and coal crashed easily. This technology is featured by agglomerate combustion of low cost MM. Experimental results in 0.5MW FBC test rig are reported. lie effects of bed temperate excess air, staged combustion on combustion and emission performance has been studied. The comparison combustion tests by using dry coal and CWM we made ha 0.5MW FBC test rig. Also coal washery sludge of different origins are also tested in the test rig. Based on the test rig comments a demonstration AFBC boiler with capacity of 35 T/H steam for utility application (6 MW) is designed. The design features will be presented in this paper Both the operation experience of test rig and demonstration unit show the developed low cost CWM FBC technology is of high combustion efficiency and low emission. This technology is being commercialized and applied in China in top priority by Chinese government.

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

    SciTech Connect

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

    1980-12-01

    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.

  10. EERC pilot-scale CFBC evaluation facility Project CFB test results. Topical report, Task 7.30

    SciTech Connect

    Mann, M.D.; Hajicek, D.R.; Henderson, A.K.; Moe, T.A.

    1992-09-01

    Project CFB was initiated at the University of North Dakota Energy and Environmental Research Center (EERC) in May 1988. Specific goals of the project were to (1) construct a circulating fluidized-bed combustor (CFBC) facility representative of the major boiler vendors` designs with the capability of producing scalable data, (2) develop a database for use in making future evaluations of CFBC technology, and (3) provide a facility for evaluating fuels, free of vendor bias for use in the - energy industry. Five coals were test-burned in the 1-MWth unit: North Dakota and Asian lignites, a Wyoming subbituminous, and Colorado and Pennsylvania bituminous coats. A total of 54 steady-state test periods were conducted, with the key test parameters being the average combustor temperature, excess air, superficial gas velocity, calcium-to-sulfur molar ratio, and the primary air-to-secondary air split. The capture for a coal fired in a CFBC is primarily dependent upon the total alkali-to-sulfur ratio. The required alkali-to ratio for 90% sulfur retention ranged from 1.4 to 4.9, depending upon coal type. While an alkali-to-ratio of 4.9 was required to meet 90% sulfur retention for the Salt Creek coal versus 1.4 for the Asian lignite, the total amount of sorbent addition required is much less for the Salt Creek coal, 4.2 pound sorbent per million Btu coal input, versus 62 pound/million Btu for the Asian lignite. The bituminous coals tested show optimal capture at combustor temperatures of approximately 1550{degree}F, with low-rank coals having optimal sulfur capture approximately 100{degree}F lower.

  11. Pressurized Fluidized Bed Combustion Second-Generation System Research and Development

    SciTech Connect

    A. Robertson; D. Horazak; R. Newby; H. Goldstein

    2002-11-01

    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.

  12. Investigation of Heat Transfer and Combustion in the Advanced Fluidized Bed Combustion.

    SciTech Connect

    Lee, S.W.

    1997-10-01

    This technical report summarizes the research conducted and progress achieved during the period from July 1, 1997 to September 30, 1997. In order to conduct the numerical modeling/simulation on the advanced swirling fluidized bed combustor (hot model), the basic governing equations are formulated based upon the continuity and momentum equations, and energy equations in the cylindrical coordinates. The chemical reaction and radiation heat transfer were considered in this modeling/simulation work. The chemical reaction and the diffusion due to concentration gradients and thermal effects are also included in the modeling for simulation. The flow system was configured in 3-D cylindrical coordinates with the uniform mesh grids. The calculation grid was set of orthogonal lines arranged in the cylindrical coordinates which includes three different directions: tangential direction (I), radial direction (i), and vertical direction (k). There are a total of 24192 grids in the system configuration including 14 slices of the tangential direction (I), 24 slices of the radial direction (j), and 72 slices of the vertical direction. Numerical simulation on the advanced swirling fluidized bed combustor is being conducted using computational fluid dynamics (CFD) code, Fluent. This code is loaded onto the supercomputer, CRAY J916 system of Morgan State University. Numerical modeling/simulation will be continued to determine the hot flow patterns, velocity profiles, static pressure profiles, and temperature profiles in the advanced swirling fluidized combustor.

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

    SciTech Connect

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

    1992-07-01

    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.

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

    SciTech Connect

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

    1992-07-01

    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.

  15. Circulating fluidized bed tehnology in biomass combustion-performance, advances and experiences

    SciTech Connect

    Mutanen, K.I.

    1995-11-01

    Development of fluidized bed combustion (FBC) was started both in North America and in Europe in the 1960`s. In Europe and especially in Scandinavia the major driving force behind the development was the need to find new more efficient technologies for utilization of low-grade fuels like different biomasses and wastes. Both bubbling fluidized bed (BFB) and circulating fluidized bed (CFB) technologies were under intensive R&D,D efforts and have now advanced to dominating role in industrial and district heating power plant markets in Europe. New advanced CFB designs are now entering the markets. In North America and especially in the US the driving force behind the FBC development was initially the need to utilize different types of coals in a more efficient and environmentally acceptable way. The present and future markets seem to be mainly in biomass and multifuel applications where there is benefit from high combustion efficiency, high fuel flexibility and low emissions such as in the pulp and paper industry. The choice between CFB technology and BFB technology is based on selected fuels, emission requirements, plant size and on technical and economic feasibility. Based on Scandinavian experience there is vast potential in the North American industry to retrofit existing oil fired, pulverized coal fired, chemical recovery or grate fired boilers with FBC systems or to build a new FBC based boiler plant. This paper will present the status of CFB technologies and will compare technical and economic feasibility of CFB technology to CFB technology to BFB and also to other combustion methods. Power plant projects that are using advanced CFB technology e.g. Ahlstrom Pyroflow Compact technology for biomass firing and co-firing of biomass with other fuels will also be introduced.

  16. Characteristics modeling for supercritical circulating fluidized bed boiler working in oxy-combustion technology

    NASA Astrophysics Data System (ADS)

    Balicki, Adrian; Bartela, Łukasz

    2014-06-01

    Among the technologies which allow to reduce greenhouse gas emission, mainly carbon dioxide, special attention deserves the idea of `zeroemission' technology based on boilers working in oxy-combustion technology. In the paper the results of analyses of the influence of changing two quantities, namely oxygen share in oxidant produced in the air separation unit, and oxygen share in oxidant supplied to the furnace chamber on the selected characteristics of a steam boiler including the degree of exhaust gas recirculation, boiler efficiency and adiabatic flame temperature, was examined. Due to the possibility of the integration of boiler model with carbon dioxide capture, separation and storage installation, the subject of the analysis was also to determine composition of the flue gas at the outlet of a moisture condensation installation. Required calculations were made using a model of a supercritical circulating fluidized bed boiler working in oxy-combustion technology, which was built in a commercial software and in-house codes.

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

    SciTech Connect

    Chindaprasirt, Prinya; Rattanasak, Ubolluk

    2010-04-15

    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.

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

    PubMed

    Chindaprasirt, Prinya; Rattanasak, Ubolluk

    2010-04-01

    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(2)SiO(3)) and 10M sodium hydroxide (NaOH) solutions at mass ratio of Na(2)SiO(3)/NaOH of 1.5 and curing temperature of 65 degrees C for 48h 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 35.0-44.0MPa 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. PMID:19854038

  19. Gaseous emissions from sewage sludge combustion in a moving bed combustor.

    PubMed

    Batistella, Luciane; Silva, Valdemar; Suzin, Renato C; Virmond, Elaine; Althoff, Chrtistine A; Moreira, Regina F P M; José, Humberto J

    2015-12-01

    Substantial increase in sewage sludge generation in recent years requires suitable destination for this residue. This study evaluated the gaseous emissions generated during combustion of an aerobic sewage sludge in a pilot scale moving bed reactor. To utilize the heat generated during combustion, the exhaust gas was applied to the raw sludge drying process. The gaseous emissions were analyzed both after the combustion and drying steps. The results of the sewage sludge characterization showed the energy potential of this residue (LHV equal to 14.5 MJ kg(-1), db) and low concentration of metals, polycyclic aromatic hydrocarbons (PAH), polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF). The concentration of CO, NOx, BTEX (benzene, toluene, ethylbenzene and xylenes) emitted from the sludge combustion process were lower than the legal limits. The overall sludge combustion and drying process showed low emissions of PCDD/PCDF (0.42 ng I-TEQ N m(-3)). BTEX and PAH emissions were not detected. Even with the high nitrogen concentration in the raw feed (5.88% db), the sludge combustion process presented NOx emissions below the legal limit, which results from the combination of appropriate feed rate (A/F ratio), excess air, and mainly the low temperature kept inside the combustion chamber. It was found that the level of CO emissions from the overall sludge process depends on the dryer operating conditions, such as the oxygen content and the drying temperature, which have to be controlled throughout the process in order to achieve low CO levels. The aerobic sewage sludge combustion process generated high SO2 concentration due to the high sulfur content (0.67 wt%, db) and low calcium concentration (22.99 g kg(-1)) found in the sludge. The high concentration of SO2 in the flue gas (4776.77 mg N m(-3)) is the main factor inhibiting PCDD/PCDF formation. Further changes are needed in the pilot plant scheme to reduce SO2 and particulate matter emissions

  20. Residues characterisation from the fluidised bed combustion of East London's solid recovered fuel.

    PubMed

    Balampanis, D E; Pollard, S J T; Simms, N; Longhurst, P; Coulon, F; Villa, R

    2010-07-01

    Waste thermal treatment in Europe is moving towards the utilisation of the combustible output of mechanical, biological treatment (MBT) plants. The standardisation of solid recovered fuels (SRF) is expected to support this trend and increase the amount of the generated combustion residues. In this work, the residues and especially the fly ashes from the fluidised bed combustion (FBC) of East London's NCV 3, Cl 2, and Hg 1 class SRF, are characterised. The following toxicity indicators have been studied: leachable chlorine, organochlorides expressed as pentachlorobenzene and hexachlorobenzene, and the heavy metals Cu, Cr, Cd, Zn, Ni, and Pb. Furthermore the mineralogical pattern of the ashes has been studied by means of XRD and SEM-EDS. The results suggest that these SRF derived ashes have significantly lower quantities of Cu, Cd, Pb, Zn, leachable Cl, and organochlorides when compared to other literature values from traditional waste thermal treatment applications. This fact highlights the importance of modern separation technologies employed in MBT plants for the removal of components rich in metals and chlorine from the combustible output fraction of SRF resulting to less hazardous residues. PMID:20231082

  1. Fine and ultrafine particles generated during fluidized bed combustion of different solid fuels

    SciTech Connect

    Urciuolo, M.; Barone, A.; D'Alessio, A.; Chirone, R.

    2008-12-15

    The paper reports an experimental study carried out with a 110-mm ID fluidized bed combustor focused on the characterization of particulates formation/emission during combustion of coal and non-fossil solid fuels. Fuels included: a bituminous coal, a commercial predried and granulated sludge (GS), a refuse-derived fuel (RDF), and a biomass waste (pine seed shells). Stationary combustion experiments were carried out analyzing the fate of fuel ashes. Fly ashes collected at the combustor exhaust were characterized both in terms of particle size distribution and chemical composition, with respect to both trace and major elements. Tapping-Mode Atomic Force Microscopy (TM-AFM) technique and high-efficiency cyclone-type collector devices were used to characterize the size and morphology of the nanometric-and micronic-size fractions of fly ash emitted at the exhaust respectively. Results showed that during the combustion process: I) the size of the nanometric fraction ranges between 2 and 65 nm; ii) depending on the fuel tested, combustion-assisted attrition or the production of the primary ash particles originally present in the fuel particles, are responsible of fine particle generation. The amount in the fly ash of inorganic compounds is larger for the waste-derived fuels, reflecting the large inherent content of these compounds in the parent fuels.

  2. West Virginia Geological Survey's role in siting fluidized bed combustion facilities

    USGS Publications Warehouse

    Smith, C.J.; King, Hobart M.; Ashton, K.C.; Kirstein, D.S.; McColloch, G.H.

    1989-01-01

    A project is presented which demonstrates the role of geology in planning and siting a fluidized bed combustion facility. Whenever a project includes natural resource utilization, cooperation between geologists and design engineers will provide an input that could and should save costs, similar to the one stated in our initial premise. Regardless of whether cost reductions stem from a better knowledge of fuel and sorbent availabilities, or a better understanding of the local hydrology, susceptibility to mine-subsidence, or other geologic hazards, the geological survey has a vital role in planning. Input to planning could help the fluidized-bed developer and design-engineer solve some economic questions and stretch the financial resources at their disposal.

  3. Exploratory and basic fluidized-bed combustion studies. Quarterly report, October-December 1979

    SciTech Connect

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

    1980-11-01

    These laboratory- and process-development-scale studies support the Fossil Energy development program for atmospheric and pressurized fluidized-bed combustion. The objective of the current program is to investigate methods for improving the utilization of limestone for SO/sub 2/ emission control in FBCs and to develop a method for predicting the performance in AFBC's and PFBC's of limestones from different sources. This report presents results from (1) an investigation of the use of water treatment of spent partially sulfated limestone to enhance its SO/sub 2/ capture capacity, (2) studies of the kinetics of the hydration of spent limestone, and (3) studies of the attrition and elutriation of limestones in fluidized beds. Results of studies of the particle-removal efficiency of the TAN-JET cyclone are also reported.

  4. Material handling systems for the fluidized-bed combustion boiler at Rivesville, West Virginia

    NASA Technical Reports Server (NTRS)

    Branam, J. G.; Rosborough, W. W.

    1977-01-01

    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.

  5. Development of a topping combustor for advanced concept pressurized fluidized-bed combustion systems

    SciTech Connect

    Domeracki, W.F.; Dowdy, T.E.; Bachovchin, D.

    1995-11-01

    A project team consisting of Foster Wheeler Development Corporation, Westinghouse Electric Corporation, Gilbert/Commonwealth and the Institute of Gas Technology, are developing a Second Generation Pressurized Fluidized Bed System. Foster Wheeler is developing a carbonizer (a partial gasifier) and a pressurized fluidized bed combustor. Both these units operate at a nominal 1600{degrees}F (870{degrees}C) for optimal sulfur capture. Since this temperature is well below the current combustion turbine combustor outlet operating temperature of 2350{degrees}F (1290{degrees}C), to reach commercialization, a topping combustor and hot gas cleanup (HGCU) equipment must be developed. Westinghouse`s efforts are focused on the development of the high temperature gas cleanup equipment and the topping combustor. This paper concentrates on the design and test of the topping combustor, which must use a low heating value syngas from the carbonizer at approximately 1600{degrees}F and 150 to 210 psi.

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

    SciTech Connect

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

    1997-10-01

    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.

  7. Manual for applying fluidized-bed-combustion residue to agricultural lands. Research report

    SciTech Connect

    Stout, W.L.; Hern, J.L.; Korcak, R.F.; Carlson, C.W.

    1988-08-01

    Atmospheric fluidized-bed combustion (AFBC) is a process that reduces sulfur emissions from coal-fired electric-generating plants. The residue from the process is a mixture of alkaline oxides, calcium sulfate, and coal ash constituent. Since 1976, USDA/ARS has investigated the potential agriculture use of the residue. The investigations comprised an extensive series of laboratory, greenhouse, field plot, and animal-feeding experiments. The best and safest use of AFBC residue in agriculture was as a substitute for agricultural lime. The report contains guidelines for appling AFBC residue to agricultural lands.

  8. Pulsed atmospheric fluidized bed combustion. Technical progress report, July 1991--September 1991

    SciTech Connect

    Not Available

    1991-10-01

    The major accomplishments during this reporting period include completion of Task 1 and progression into Phase II, Task 2 design activities. A brief laboratory-scale test was conducted during this reporting period to confirm heat transfer coefficients for various sections of the Pulsed Atmospheric Fluidized bed Combustion (PAFBC) system. The heat transfer coefficient was determined to be approximately 50 Btu/hr ft{sup 2} {degrees}F inside the eductor and tailpipe of the pulse combustor as thin the fluidized bed. well as for the surfaces immersed within the fluidized bed. Communications with potential host sites for the Phase III field demonstration activities continued during this reporting period. These discussions along with discussions with environmental regulatory personnel in the State of Maryland indicate that the throughput of the field demonstration facility should be increased to greater than 36 million Btu/hr. An 8 in. {times} 8 in. fluidized bed unit would be too small to satisfy this requirement; its projected firing rate is only 33 million Btu/hr. Major effort during this reporting period was devoted to assessing the reasonableness of increasing the size of the field test facility from a technical and cost standpoint.

  9. Thermal valorization of footwear leather wastes in bubbling fluidized bed combustion.

    PubMed

    Bahillo, A; Armesto, L; Cabanillas, A; Otero, J

    2004-01-01

    Transformation of hide (animal skins) into leather is a complicated process during which significant amounts of wastes are generated. Footwear is the sector that consumes the major part of leather (60%). Logically, this industry is producing the largest quantity of leather wastes. The objective of this work was to demonstrate the technical feasibility of fluidized bed technology to recover the energy from burning footwear leather wastes. Considering the characteristics of leather waste, especially the heating value (12.5-21 MJ/kg), it can be considered a fairly good fuel. Moreover, leather waste has suitable characteristics for combustion, e.g., high volatile matter (76.5%) and low ash content (5.2%). Two factors deserve special attention: N3O and NOx emissions as a consequence of its unusual high nitrogen content (14.1%) and the chromium speciation because chromium is the main element of ash (3.2%) due to its use in leather tanning. A series of experiments has been carried out in a 0.1 MWt bubbling fluidized bed pilot plant. The combustion efficiency, flue gas composition and chromium speciation were investigated. Despite having high nitrogen content, a low conversion rate of fuel-N to NOx and N2O was attained. Chromium was concentrated in the solid streams and it was consistently found as Cr(III+); no presence of Cr(VI+) was detected. PMID:15504671

  10. Data summary of municipal solid waste management alternatives. Volume 5, Appendix C, Fluidized-bed combustion

    SciTech Connect

    1992-10-01

    This appendix provides information on fluidized-bed combustion (FBC) technology as it has been applied to municipal waste combustion (MWC). A review of the literature was conducted to determine: (1) to what extent FBC technology has been applied to MWC, in terms of number and size of units was well as technology configuration; (2) the operating history of facilities employing FBC technology; and (3) the cost of these facilities as compared to conventional MSW installations. Where available in the literature, data on operating and performance characteristics are presented. Tabular comparisons of facility operating/cost data and emissions data have been complied and are presented. The literature review shows that FBC technology shows considerable promise in terms of providing improvements over conventional technology in areas such as NOx and acid gas control, and ash leachability. In addition, the most likely configuration to be applied to the first large scale FBC dedicated to municipal solid waste (MSW) will employ circulating bed (CFB) technology. Projected capital costs for the Robbins, Illinois 1600 ton per day CFB-based waste-to-energy facility are competitive with conventional systems, in the range of $125,000 per ton per day of MSW receiving capacity.

  11. Identification of barriers to the use of atmospheric fluidized bed combustion in Kentucky

    SciTech Connect

    Not Available

    1990-08-01

    Both Kentucky and the USDOE are committed to development and commercialization of Fluidized Bed Combustion. Kentucky has committed $10 million to, and is a full partner in, the utility-scale 160 MW Atmospheric Fluidized Bed Combustion (AFBC) Demonstration Plant at the Tennessee Valley Authority's Shawnee Steam Plant in Paducah, Kentucky. Kentucky purchased and operates an AFBC pilot plant and conducts tests on alternative coal types, limestone types, boiler-tube corrosion/erosion and other research. The Kentucky General Assembly established a tax credit for the use of AFBC installations. It provides a five year exemption from sales tax, corporate tax, and other taxes for facilities installing AFBC in Kentucky. Despite government and industry commitment to AFBC, despite is potential advantages, and despite its commercial use in several parts of the United States, there is only one industrial facility burning coal using AFBC in Kentucky. This facility uses two units, each rated 60,000 pound per hour AFBC units. One of the driving forces behind the decision to use AFBC at this facility was USDOE funding. Two boilers out of the approximately 800 industrial boilers in the state cannot be considered impressive penetration of the technology. This project was designed to investigate why there is little use of AFBC in Kentucky and to recommend measures to facilitate or encourage its use. 11 figs.

  12. Fluidized bed combustion of pelletized biomass and waste-derived fuels

    SciTech Connect

    Chirone, R.; Scala, F.; Solimene, R.; Salatino, P.; Urciuolo, M.

    2008-10-15

    The fluidized bed combustion of three pelletized biogenic fuels (sewage sludge, wood, and straw) has been investigated with a combination of experimental techniques. The fuels have been characterized from the standpoints of patterns and rates of fuel devolatilization and char burnout, extent of attrition and fragmentation, and their relevance to the fuel particle size distribution and the amount and size distribution of primary ash particles. Results highlight differences and similarities among the three fuels tested. The fuels were all characterized by limited primary fragmentation and relatively long devolatilization times, as compared with the time scale of particle dispersion away from the fuel feeding ports in practical FBC. Both features are favorable to effective lateral distribution of volatile matter across the combustor cross section. The three fuels exhibited distinctively different char conversion patterns. The high-ash pelletized sludge burned according to the shrinking core conversion pattern with negligible occurrence of secondary fragmentation. The low-ash pelletized wood burned according to the shrinking particle conversion pattern with extensive occurrence of secondary fragmentation. The medium-ash pelletized straw yielded char particles with a hollow structure, resembling big cenospheres, characterized by a coherent inorganic outer layer strong enough to prevent particle fragmentation. Inert bed particles were permanently attached to the hollow pellets as they were incorporated into ash melts. Carbon elutriation rates were very small for all the fuels tested. For pelletized sludge and straw, this was mostly due to the shielding effect of the coherent ash skeleton. For the wood pellet, carbon attrition was extensive, but was largely counterbalanced by effective afterburning due to the large intrinsic reactivity of attrited char fines. The impact of carbon attrition on combustion efficiency was negligible for all the fuels tested. The size

  13. Development of methods to predict agglomeration and deposition in fluidized-bed combustion systems (FBCS). Topical report

    SciTech Connect

    Mann, M.D.; Henderson, A.K.; Swanson, M.L.; Allan, S.E.

    1996-02-01

    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 fluidized bed combustion of lignite and petroleum coke is described in this paper.

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

    SciTech Connect

    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

    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.

  15. Improving performance of CFB boiler by adopting end effect of bed exit of CFB combustor

    SciTech Connect

    Zheng, Q.Y.; Jin, Y.

    1997-12-31

    Experiments indicate that the end effect of the bed exit of a CFB strongly influences the bulk density profile and internal circulation of bed materials in a CFB combustor. A well designed geometry of the bed exit of CFBC can create abundant internal circulation of bed materials in furnace and reduce external circulation in circulating loop of CFBC, then consequently improves the comprehensive performance of CFB boiler. This paper is devoted to analyzing the mechanism of the end effect of the bed exit on the hydrodynamics in a CFB by presenting test results. Design criteria and a suggestion for getting the end effect will also be presented.

  16. A particulate model of solid waste incineration in a fluidized bed combining combustion and heavy metal vaporization

    SciTech Connect

    Mazza, G.; Falcoz, Q.; Gauthier, D.; Flamant, G.

    2009-11-15

    This study aims to develop a particulate model combining solid waste particle combustion and heavy metal vaporization from burning particles during MSW incineration in a fluidized bed. The original approach for this model combines an asymptotic combustion model for the carbonaceous solid combustion and a shrinking core model to describe the heavy metal vaporization. A parametric study is presented. The global metal vaporization process is strongly influenced by temperature. Internal mass transfer controls the metal vaporization rate at low temperatures. At high temperatures, the chemical reactions associated with particle combustion control the metal vaporization rate. A comparison between the simulation results and experimental data obtained with a laboratory-scale fluid bed incinerator and Cd-spiked particles shows that the heavy metal vaporization is correctly predicted by the model. The predictions are better at higher temperatures because of the temperature gradient inside the particle. Future development of the model will take this into account. (author)

  17. Polycyclic aromatic hydrocarbons and organic matter associated to particulate matter emitted from atmospheric fluidized bed coal combustion

    SciTech Connect

    Mastral, A.M.; Callen, M.S.; Garcia, T.

    1999-09-15

    The polycyclic aromatic hydrocarbons (PAH) and the organic matter (OM) content associated with particulate matter (PM) emissions from atmospheric fluidized bed coal combustion have been studied. The two main aims of the work have been (a) to study OM and PAH emissions as a function of the coal fluidized bed combustion (FBC) variables in solid phase and (b) to check if there is any correlation between OM and PAH contained in the PM. The combustion was carried out in a laboratory scale plant at different combustion conditions: temperature, percentage of oxygen excess, and total air flow. PAH associated on the particulate matter have been analyzed by fluorescence spectroscopy in the synchronous mode (FS) after PM extraction by sonication with dimethylformamide (DMF). It can be concluded that there is not a direct relationship between the OM content and the PAH supported in the PM emitted. In addition, neither PM or OM show dependence between themselves.

  18. The distribution of heavy metals during fluidized bed combustion of sludge (FBSC).

    PubMed

    Van de Velden, M; Dewil, R; Baeyens, J; Josson, L; Lanssens, P

    2008-02-28

    During combustion of wastewater treatment sludge, the inorganic constituents are converted into ash which contains the major fraction of the heavy metals present. The behaviour of heavy metals in combustion processes has been studied extensively for mostly coal combustion and waste incineration. For biomass and sludge, literature data are scarce and mostly limited to laboratory experiments. The present paper assesses the partitioning of eight heavy metals (Hg, As, Cd, Cu, Pb, Cr, Ni and Zn) in the different residues from a large-scale fluidized bed sludge combustor of 4.4 m i.d. The origin of the sludge is mostly from treating urban wastewaters (>90%), although some mixed sludge (urban+industrial, <10%) is also burnt. The different residues (bottom ash, fly ash, filter cake, scrubber effluent and stack emissions) were sampled and analysed during 33 weeks, spread over a period of 1 year. The mass balance of relevant heavy metals closes for 96.5%, inaccuracies being related to the unsteadiness of the process, the accuracy of the mass flow data monitored at the plant, and on collecting representative samples. It is also shown that all heavy metals under scrutiny, except Hg, are concentrated in the fly ash as collected in the electrostatic precipitator. PMID:17601665

  19. Particle-metal interactions during combustion of pulp and paper biomass in a fluidized bed combustor

    SciTech Connect

    Eldabbagh, F.; Ramesh, A.; Kozinski, J.A.; Hawari, J.; Hutny, W.

    2005-08-01

    We compare interactions between metals and solid particles during the classic fluidized bed combustion (FBC) and a new low-high-low temperature (LHL) combustion of selected biomass. The biomass was a mixture of bark and pine wood residues typically used by a paper mill as a source of energy. Experiments, conducted on a pilot scale, reveal a clear pattern of surface predominance of light metals (Ca, Na, K) and core predominance of heavy metals (Cd, Cr) within the LHL-generated particles. No such behavior was induced by the FBC. Metal migration is linked to the evolution of inorganic particles. A composite picture of the metal rearrangements in the particles was obtained by a combination of independent analytical techniques including electron probe microanalysis, field emission scanning electron microscopy, inductively coupled plasma spectrometry, and X-ray diffractometry. It is suggested that the combination of (1) the high-temperature region in the LHL and (2) changes in the surface free energy of the particles is the driving force for the metal-particle behavior. Important practical implications of the observed phenomena are proposed, including removal of hazardous submicron particulate and reduction in fouling/slagging during biomass combustion. These findings may contribute to redesigning of currently operating FBC units to generate nonhazardous, nonleachable, reusable particles where heavy metals are immobilized while environmental and technological problems reduced.

  20. Alkali metals in circulating fluidized bed combustion of biomass and coal: measurements and chemical equilibrium analysis

    SciTech Connect

    Michal P. Glazer; Nafees A. Khan; Wiebren de Jong; Hartmut Spliethoff; Heiko Schuermann; Penelope Monkhouse

    2005-10-01

    Combustion and co-combustion experiments with four kinds of straw, specially selected for their different alkali, Cl, and Si contents, and Colombian black coal were carried out in a circulating fluidized bed (CFB) reactor at Delft University of Technology. The influence of operating conditions and fuel composition on the release of the alkali compounds to the gas phase was investigated. The amount of the total gas-phase sodium and potassium compounds in the flue gases was measured with excimer laser induced fluorescence (ELIF). The results show that the release of gaseous alkali species depends on fuel composition, in particular the K/Cl and K/Si ratios in the fuel. The fuels with high K and Cl values show higher concentrations of the gaseous alkalis. A synergetic effect of the co-combustion with coal was observed, which led to a strong decrease in gaseous alkali concentrations. Together with experiments, chemical equilibrium modeling was performed to help in interpreting the experimental data. The calculations confirmed that the equilibrium is very strongly influenced by the composition of the fuel blend. Moreover, the simulations provided more information on sequestering of alkali species. 22 refs., 5 figs., 4 tabs.

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

    SciTech Connect

    Hongcang Zhou; Baosheng Jin; Rui Xiao; Zhaoping Zhong; Yaji Huang

    2009-04-15

    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.

  2. Development of topping combustor for advanced concept pressurized fluidized-bed combustion

    SciTech Connect

    Domeracki, W.F.; Dowdy, T.E.; Bachovchin, D.

    1994-10-01

    The objective of this program is to develop a topping combustor to operate in a Second-Generation Pressurized Fluidized Bed (PFBC) Combined Cycle power generation system. The combustor must be able to: lightoff with a high heating value fuel and compressor discharge air to heat the fluidized bed(s) and provide power for PFBC and carbonizer off-line; operate with 1,600 F oxygen depleted air from the PFBC and high heating value fuel to handle carbonizer off-line conditions; ramp up to 100% carbonizer syngas firing (normal operation) by firing a blend of decreasing high heating value fuel and increasing low heating value syngas; utilize the vitiated air, at temperatures up to 1,600 F for as much cooling of the metal combustor as possible, thus minimizing the compressor bypass air needed for combustor cooling; provide an acceptance exit temperature pattern at the desired burner outlet temperature (BOT); minimize the conversion of fuel bound nitrogen (FBN) present in the syngas to NO{sub x}; and have acceptably high combustion efficiency, and low emissions of carbon monoxide, UHC, etc. This paper reports the results of tests of a 14 inch diameter topping combustor with a modified fuel-rich zone conducted in June 1993, design of an 18 inch diameter topping combustor to be tested in June 1994 and afterwards, and results of a 50% scale cold flow model which has been built and tested.

  3. Pollutant emission characteristics of rice husk combustion in a vortexing fluidized bed incinerator.

    PubMed

    Duan, Feng; Chyang, Chiensong; Chin, Yucheng; Tso, Jim

    2013-02-01

    Rice husk with high volatile content was burned in a pilot scale vortexing fluidized bed incinerator. The fluidized bed incinerator was constructed of 6 mm stainless steel with 0.45 m in diameter and 5 m in height. The emission characteristics of CO, NO, and SO2 were studied. The effects of operating parameters, such as primary air flow rate, secondary air flow rate, and excess air ratio on the pollutant emissions were also investigated. The results show that a large proportion of combustion occurs at the bed surface and the freeboard zone. The SO2 concentration in the flue gas decreases with increasing excess air ratio, while the NOx concentration shows reverse trend. The flow rate of secondary air has a significant impact on the CO emission. For a fixed primary air flowrate, CO emission decreases with the secondary air flowrate. For a fixed excess air ratio, CO emission decreases with the ratio of secondary to primary air flow. The minimum CO emission of 72 ppm is attained at the operating condition of 40% excess air ratio and 0.6 partition air ratio. The NOx and SO2 concentrations in the flue gas at this condition are 159 and 36 ppm, which conform to the EPA regulation of Taiwan. PMID:23596954

  4. Design and construction of a circulating fluidized bed combustion facility for use in studying the thermal remediation of wastes

    NASA Astrophysics Data System (ADS)

    Rink, Karl K.; Kozinski, Janusz A.; Lighty, JoAnn S.; Lu, Quing

    1994-08-01

    Fluidized bed combustion systems have been widely applied in the combustion of solid fossil fuels, particularly by the power generation industry. Recently, attention has shifted from the conventional bubbling fluidized bed (BFB) to circulating fluidized bed (CFB) combustion systems. Inherent advantages of CFB combustion such as uniform temperatures, excellent mixing, high combustion efficiencies, and greater fuel flexibility have generated interest in the feasibility of CFB combustion systems applied to the thermal remediation of contaminated soils and sludges. Because it is often difficult to monitor and analyze the combustion phenomena that occurs within a full scale fluidized bed system, the need exists for smaller scale research facilities which permit detailed measurements of temperature, pressure, and chemical specie profiles. This article describes the design, construction, and operation of a pilot-scale fluidized bed facility developed to investigate the thermal remediation characteristics of contaminated soils and sludges. The refractory-lined reactor measures 8 m in height and has an external diameter of 0.6 m. The facility can be operated as a BFB or CFB using a variety of solid fuels including low calorific or high moisture content materials supplemented by natural gas introduced into the fluidized bed through auxiliary fuel injectors. Maximum firing rate of the fluidized bed is approximately 300 kW. Under normal operating conditions, internal wall temperatures are maintained between 1150 and 1350 K over superficial velocities ranging from 0.5 to 4 m/s. Contaminated material can be continuously fed into the fluidized bed or introduced as a single charge at three different locations. The facility is fully instrumented to allow time-resolved measurements of gaseous pollutant species, gas phase temperatures, and internal pressures. The facility has produced reproducible fluidization results which agree well with the work of other researchers. Minimum

  5. Emissions from the combustion of eucalypt and pine chips in a fluidized bed reactor.

    PubMed

    Vicente, E D; Tarelho, L A C; Teixeira, E R; Duarte, M; Nunes, T; Colombi, C; Gianelle, V; da Rocha, G O; Sanchez de la Campa, A; Alves, C A

    2016-04-01

    Interest in renewable energy sources has increased in recent years due to environmental concerns about global warming and air pollution, reduced costs and improved efficiency of technologies. Under the European Union (EU) energy directive, biomass is a suitable renewable source. The aim of this study was to experimentally quantify and characterize the emission of particulate matter (PM2.5) resulting from the combustion of two biomass fuels (chipped residual biomass from pine and eucalypt), in a pilot-scale bubbling fluidized bed (BFB) combustor under distinct operating conditions. The variables evaluated were the stoichiometry and, in the case of eucalypt, the leaching of the fuel. The CO and PM2.5 emission factors were lower when the stoichiometry used in the experiments was higher (0.33±0.1 g CO/kg and 16.8±1.0 mg PM2.5/kg, dry gases). The treatment of the fuel by leaching before its combustion has shown to promote higher PM2.5 emissions (55.2±2.5 mg/kg, as burned). Organic and elemental carbon represented 3.1 to 30 wt.% of the particle mass, while carbonate (CO3(2-)) accounted for between 2.3 and 8.5 wt.%. The particulate mass was mainly composed of inorganic matter (71% to 86% of the PM2.5 mass). Compared to residential stoves, BFB combustion generated very high mass fractions of inorganic elements. Chloride was the water soluble ion in higher concentration in the PM2.5 emitted by the combustion of eucalypt, while calcium was the dominant water soluble ion in the case of pine. PMID:27090717

  6. Evaluation of the behavior of Colombian coals during the combustion in fixed bed

    SciTech Connect

    Giraldo, M.; Chejne, F.; Hill, A.

    2000-07-01

    The improvements in the technological processes that have coal as energy source must be based on the knowledge of physical and chemical properties of coal and in the knowledge of its evolution during the combustion process. These characteristics are involved in the coal behavior. Moreover, the coal porosity has an important relevance on the reaction rate and in diverse physical and chemical properties, and therefore, is a key parameter in the usefulness of coal. This project includes studies about Colombian coal combustion and its kinetic behavior. The coal was characterized and classified by particle size,and origin. In this research project, the physical and chemical properties of coal that affect its applicability in different kinds of technological processes have been studied as well as the characteristics that could be related to pollutant generation. The study considers the following issues: the types and level of criteria pollutant precursor compounds such as sulfur and nitrogen in coal, the influence of particle size and porosity in the generation of pollutant species, the participation of pollutant species in the combustion process, and basic properties such as heat capacity, and heat effects related to the conversion of coal during heating test. Coal from Antioquia, Valle del Cauca and Cundinamarca Regions were used. These coals are used domestically by the industrial and power sector. Particle sizes of 4, 2.5 and 1 cm were used from each one of these coals. The combustion tests were done in a fixed bed pilot furnace. The amount of air used was controlled during the experiment. In addition, air and gas flow, concentration and temperatures were registered. This paper presents a description of: characteristics of each test, composition of generated gases, and the influence of the particle size and coal origin in the pollutant emissions, also includes the results of test done in different samples took along each test.

  7. Carbon attrition during the circulating fluidized bed combustion of a packaging-derived fuel

    SciTech Connect

    Mastellone, M.L.; Arena, U. |

    1999-05-01

    Cylindrical pellets of a market-available packaging-derived fuel, obtained from a mono-material collection of polyethylene terephthalate (PET) bottles, were batchwise fed to a laboratory scale circulating fluidized bed (CFB) combustor. The apparatus, whose riser was 41 mm ID and 4 m high, was operated under both inert and oxidizing conditions to establish the relative importance of purely mechanical attrition and combustion-assisted attrition in generating carbon fines. Silica sand particles of two size distributions were used as inert materials. For each run, carbon load and carbon particle size distribution in the riser and rates of attrited carbon fines escaping the combustor were determined as a function of time. A parallel investigation was carried out with a bubbling fluidized bed (BFB) combustor to point out peculiarities of attrition in CFB combustors. After devolatilization, PET pellets generated fragile aggregates of char and sand, which easily crumbled, leading to single particles, partially covered by a carbon-rich layer. The injected fixed carbon was therefore present in the bed in three phases: an A-phase, made of aggregates of sand and char, an S-phase, made of individual carbon-covered sand particles and an F-phase, made of carbon fines, abraded by the surfaces of the A- and S-phases. The effects of the size of inert material on the different forms under which fixed carbon was present in the bed and on the rate of escape of attrited carbon fines from the combustor were investigated. Features of carbon attrition in CFB and BFB combustors are discussed.

  8. Does carbon monoxide burn inside a fluidized bed; A new model for the combustion of coal char particles in fluidized beds

    SciTech Connect

    Hayhurst, A.N. )

    1991-05-01

    Beds of silica sand were fluidized by mixtures of C{sub 3}H{sub 8}, CH{sub 4}, or CO with air. Staring from cold the way such a bed behaved before it reached a steady state was observed visually. In addition, high-speed cine films were taken, as well as measurements of the loudness of the noise emitted. These beds behave in a way indicating that such hot gas mixtures at up to 1000{degrees}C do not burn in the interstices between the sand particles. Instead, combustion occurs either above the bed or in the ascending bubbles. Measurements of the diameter (d{sub ig}) of a bubble made immediately prior to ignition confirmed that the ignition temperature (T{sub ig}) of the bubble varies with d{sub ig} {proportional to} exp (E{sub ig}/RT{sub ig}), so that larger bubbles ignite at lower temperatures. It proved possible to generate combustion of these gas mixtures in the particulate phase by adding Pt-coated catalyst pellets. This leads to a new model for the burning of char particles in a fluidized bed. In the model, char is first oxidized to CO with the reaction C{sub s} + 1/20{sup b} {yields} CO occurring mainly inside the pores of each particle. The resulting CO burns either above the bed or in bubbles rising up the bed, but not in the particulate phase. Considerable uncertainties exist as to the correct values of Nusselt and Sherwood numbers, as well as of, e.g., the intrinsic rate constant for the initial production of CO. However, the model is capable of predicting the temperatures observed for char particles burning in fluidized beds. This paper addresses some of the problems of O{sub 2} diffusing inside the pores of a char particle and then reacting to give CO.

  9. Nitrogen oxides, sulfur trioxide, and mercury emissions during oxy-fuel fluidized bed combustion of Victorian brown coal.

    PubMed

    Roy, Bithi; Chen, Luguang; Bhattacharya, Sankar

    2014-12-16

    This study investigates, for the first time, the NOx, N2O, SO3, and Hg emissions from combustion of a Victorian brown coal in a 10 kWth fluidized bed unit under oxy-fuel combustion conditions. Compared to air combustion, lower NOx emissions and higher N2O formation were observed in the oxy-fuel atmosphere. These NOx reduction and N2O formations were further enhanced with steam in the combustion environment. The NOx concentration level in the flue gas was within the permissible limit in coal-fired power plants in Victoria. Therefore, an additional NOx removal system will not be required using this coal. In contrast, both SO3 and gaseous mercury concentrations were considerably higher under oxy-fuel combustion compared to that in the air combustion. Around 83% of total gaseous mercury released was Hg(0), with the rest emitted as Hg(2+). Therefore, to control harmful Hg(0), a mercury removal system may need to be considered to avoid corrosion in the boiler and CO2 separation units during the oxy-fuel fluidized-bed combustion using this coal. PMID:25402169

  10. Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion system. Final technical report

    SciTech Connect

    Lee, Seong W.

    1996-11-01

    Research is presented on erosion and corrosion of fluidized bed combustor component materials. The characteristics of erosion of in-bed tubes was investigated. Anti-corrosion measures were also evaluated.

  11. Assessment of sorbent reactivation by water hydration for fluidized bed combustion application

    SciTech Connect

    Fabio Montagnaro; Piero Salatino; Fabrizio Scala; Yinghai Wu; Edward J. Anthony; Lufei Jia

    2006-06-15

    Disposal of fluidized bed combustion (FBC) solid residues currently represents one of the major issues in FBC design and operation, and contributes significantly to its operating cost. This issue has triggered research activities on the enhancement of sorbent utilization for in situ sulfur removal. The present study addresses the effectiveness of the reactivation by liquid water hydration of FB spent sorbents. Two materials are considered in the study, namely the bottom ash from the operation of a full-scale utility FB boiler and the raw commercial limestone used in the same boiler. Hydration-reactivation tests were carried out at temperatures of 40{sup o}C and 80{sup o}C and for curing times ranging from 15 minutes to 2d, depending on the sample. The influence of hydration conditions on the enhancement of sulfur utilization has been assessed. A combination of methods has been used to characterize the properties of liquid water-hydrated materials

  12. Fluidized-bed combustion process evaluation and program support. Annual report, October 1979-September 1980

    SciTech Connect

    Johnson, I.; Podolski, W.F.; Swift, W.M.; Carls, E.L.; Helt, J.E.; Henry, R.F.; Herzenberg, C.L.; Hanway, J.E.; Griggs, K.E.

    1981-03-01

    The purpose of this program is to support the pressurized fluidized-bed combustion project management team at Morgantown Energy Technology Center by providing a core group of experienced personnel (1) to prepare (a) program interaction plans suitable for recommending program needs and (b) recommendations for the DOE-PFBC development program, (2) to analyze data and designs for two large pilot-scale PFBC programs (i.e., Curtiss-Wright and IEA Grimethorpe), and (3) to participate in design/review for the large PFBC programs. Results are reported on a development methodology for the commercialization of PFBC technology, a FBC instrumentation state-of-the-art review, the development of a sodium sulfate dew point measurement instrument, and the evaluation of cyclones for hot gas cleanup.

  13. Modified graphical autocatalytic set model of combustion process in circulating fluidized bed boiler

    NASA Astrophysics Data System (ADS)

    Yusof, Nurul Syazwani; Bakar, Sumarni Abu; Ismail, Razidah

    2014-07-01

    Circulating Fluidized Bed Boiler (CFB) is a device for generating steam by burning fossil fuels in a furnace operating under a special hydrodynamic condition. Autocatalytic Set has provided a graphical model of chemical reactions that occurred during combustion process in CFB. Eight important chemical substances known as species were represented as nodes and catalytic relationships between nodes are represented by the edges in the graph. In this paper, the model is extended and modified by considering other relevant chemical reactions that also exist during the process. Catalytic relationship among the species in the model is discussed. The result reveals that the modified model is able to gives more explanation of the relationship among the species during the process at initial time t.

  14. Fabrication and properties of foam geopolymer using circulating fluidized bed combustion fly ash

    NASA Astrophysics Data System (ADS)

    Liu, Ze; Shao, Ning-ning; Wang, Dong-min; Qin, Jun-feng; Huang, Tian-yong; Song, Wei; Lin, Mu-xi; Yuan, Jin-sha; Wang, Zhen

    2014-01-01

    In recent years, circulating fluidized bed combustion fly ash (CFA) is used as a raw material for geopolymer synthesis. Hydrogen peroxide was employed as a foaming agent to prepare CFA-based foam geopolymer. The particle distribution, mineral composition, and chemical composition of CFA were examined firstly. Geopolymerization products were characterized by mechanical testing, scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray fluorescence (XRF). The CFA-based foam geopolymer was successfully fabricated with different contents of hydrogen peroxide and exhibited uncompleted alkali reaction and reasonable strength with relative low atomic ratios of Si/Al and Si/Na. Type-C CFA in this research could be recycled as an alternative source material for geopolymer production.

  15. Land application uses of pressurized fluidized-bed combustion (PFBC) ash

    SciTech Connect

    Dick, W.A.; Wolfe, W.

    1993-06-01

    Dry alkaline flue gas desulfurization by-products (dry lime and limestone FGD scrubber ashes) including the American Electric Power (AEP) Tidd PFBC bed and cyclone ash, are being evaluated for beneficial uses via land application for agriculture, mine reclamation, and soil stabilization in a 5 year study that began December, 1990. A 1989 Battelle Memorial Institute report had recommended that the highest priority in stimulating reuse of FGD by-products was the sponsoring of in-field research of coal combustion products generated from high sulfur midwestern coals to (a) better understand and quantify the leach rate, fate and transport of sulfates and trace metals and (b) demonstrate the level of protection necessary to build public acceptance of land-based reuses.

  16. SUPERFUND TREATABILITY CLEARINGHOUSE: BDAT TREATABILITY DATA FOR SOILS, SLUDGES AND DEBRIS FROM THE CIRCULATING BED COMBUSTION (CBC) PROCESS

    EPA Science Inventory

    The two papers provide a general overview of the Ogden circulating bed combustion and summary data of both PCB laden soils for EPA-TSCA and a test on RCRA liquid organic wastes for the California Air Resources Board (CARB). This abstract will discuss the results of the PCB...

  17. 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

    ... 10 Energy 4 2010-01-01 2010-01-01 false Use of fluidized bed combustion not feasible-general requirement for permanent exemptions. 503.10 Section 503.10 Energy DEPARTMENT OF ENERGY (CONTINUED) ALTERNATE... any supplement thereto required by OFE must include the following evidence: (1) If use of a method...

  18. Fuel-Nitrogen Evolution During Fluidized Bed Oxy-Coal Combustion

    NASA Astrophysics Data System (ADS)

    Sanchez, Astrid; Mondragon, Fanor; Eddings, Eric G.

    FTIR, thermo-gravimetric analysis techniques and molecular modelling were employed to study the effect of CO2 on fuel-nitrogen evolution under oxy-combustion conditions. The main objective is to compare NOx emissions at several molar fractions of O2 using Ar or CO2 as balance gas in a fluidized bed reactor. A char with about 16% N content was prepared by pyrolysis of polyacrylonitrile. This sample facilitated NOx evolution experiments due to the abundance of nitrogen complexes, and aided the identification and quantification of several N species by means ofFTIR. Results indicate that the presence of CO2 enhances NO2 formation. A complementary study was carried out by molecular modelling of the experimental reactions using the Gaussian 03 package. Different heterogeneous and homogeneous interactions between CO2 and char N-species were simulated. The results thus obtained show that the presence of CO2 during combustion can facilitate NCO formation which is a very reactive intermediate species that can be readily oxidized in the gaseous phase.

  19. Combustion tests of a turbine simulator burning low Btu fuel from a fixed bed gasifier

    SciTech Connect

    Cook, C.S.; Abuaf, N.; Feitelberg, A.S.; Hung, S.L.; Najewicz, D.J.; Samuels, M.S.

    1993-11-01

    One of the most efficient and environmentally compatible coal fueled power generation technologies is the integrated gasification combined cycle (IGCC) concept. Commercialization of the IGCC/HGCU concept requires successful development of combustion systems for high temperature low Btu fuel in gas turbines. Toward this goal, a turbine combustion system simulator has been designed, constructed, and fired with high temperature low Btu fuel. Fuel is supplied by a pilot scale fixed bed gasifier and hot gas desulfurization system. The primary objectives of this project are: (1) demonstration of long term operability of the turbine simulator with high temperature low Btu fuel; (2) measurement of NO{sub x}, CO, and particulate emissions; and (3) characterization of particulates in the fuel as well as deposits in the fuel nozzle, combustor, and first stage nozzle. In a related project, a reduced scale rich-quench-lean (RQL) gas turbine combustor has been designed, constructed, and fired with simulated low Btu fuel. The overall objective of this project is to develop an RQL combustor with lower conversion of fuel bound nitrogen (FBN) to NO{sub x} than a conventional combustor.

  20. Combustion of municipal solid wastes with oil shale in a circulating fluidized bed. Final report

    SciTech Connect

    1996-06-30

    The problem addressed by our invention is that of municipal solid waste utilization. The dimensions of the problem can be visualized by the common comparison that the average individual in America creates in five years time an amount of solid waste equivalent in weight to the Statue of Liberty. The combustible portion of the more than 11 billion tons of solid waste (including municipal solid waste) produced in the United States each year, if converted into useful energy, could provide 32 quads per year of badly needed domestic energy, or more than one-third of our annual energy consumption. Conversion efficiency and many other factors make such a production level unrealistic, but it is clear that we are dealing with a very significant potential resource. This report describes research pertaining to the co-combustion of oil shale with solid municipal wastes in a circulating fluidized bed. The oil shale adds significant fuel content and also constituents that can possible produce a useful cementitious ash.

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

    SciTech Connect

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

    1988-05-01

    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 and Southern Research Institute entered into a program to monitor the performance of the fabric filter at the pilot plant. The objective of the program was to determine if unique characteristics of AFBC operation or emissions would require special design criteria or operating procedures in the application of fabric filtration to utility-size AFBC boilers. With reverse-gas cleaning the fabric filter experienced high tubesheet pressure drop while operating at low filtering air-to-cloth values and with low residual dustcake areal densities compared to fabric filters downstream from pulverized-coal boilers. This implied that the AFBC fly ash had properties distinct from those of pulverized-coal fly ash. Implementaion of reverse-gas cleaning with sonic assistance resulted in lower operating pressure drops at higher filtering air-to-cloth values, although slightly higher than comparable data from baghouses filtering pulverized-coal fly ash. Fly ash analyses showed that the AFBC ash particles are generally smaller, more irregualr in shape, and the dustcakes are lighter and more porous than those formed from pulverized-coal fly ashes. 8 refs., 18 figs., 7 tabs.

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

    SciTech Connect

    Ashworth, R.A.; Plessinger, D.A.; Sommer, T.M.; Keener, H.M.; Webner, R.L.

    1997-03-31

    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.

  3. Characteristics of high quality sorbent for fluidized bed combustion and problems of maintaining uniform reactivity

    SciTech Connect

    Bain, R.J. . Dept. of Geology)

    1993-03-01

    Fluidized bed combustion of coal is considered one of the more promising clean coal technologies for the future. While much research has gone into the design and operation of FBC units, there is little concern for what characterizes a high quality sorbent and the source of such a sorbent. Carbonate rocks, limestone and dolomite, have been tested extensively as sorbents and primarily two rock characteristics appear to significantly control reactivity: composition and texture. Calcium carbonate is more reactive than magnesium carbonate where all other rock characteristics are the same. In considering texture, highest reactivity is measured for carbonate rocks which consist of homogeneous, euhedral crystals ranging in size from .05 to .2 mm and which possess uniform intercrystalline porosity. The most reactive material possesses both high calcium content, uniform microcrystalline texture and intercrystalline porosity, however, such material is not very abundant in nature and is not locally available to midcontinent facilities. Sucrosic dolomite, which possesses uniform microcrystalline texture and intercrystalline porosity has high rank reactivity. While this rock is quite common, it occurs as beds, generally less than twenty feet thick, interlayered with less reactive dolomite types. Therefore, without selective quarrying methods, production of sorbent with uniformly high reactivity will be impossible.

  4. High efficiency power generation from coal and wastes utilizing high temperature air combustion technology (Part 1: Performance of pebble bed gasifier for coal and wastes)

    SciTech Connect

    Kosaka, Hitoshi; Iwahashi, Takashi; Yoshida, Nobuhiro; Tsuji, Kiyoshi; Yoshikawa, Kunio; Kiga, Takashi; Tamamushi, Fumihiro; Makino, Kenji; Oonish, Hiroshi

    1998-07-01

    A new concept of a gasifier for coal and wastes is proposed where entrained bed and fixed pebble bed are combined. Main features of this pebble bed gasifier are high efficiency molten slag capture, high efficiency gasification and compactness. Coal and RFD combustion experiments using the pebble bed gasifier demonstrated high efficiency capture and continuous extraction of molten slag as well as complete char combustion with extra ordinarily short residence time of pulverized coal and crushed RDF at the temperature level of about 1,500 C within the pebble bed. Durability tests using high temperature electric furnace has shown that high density alumna is a good candidate for pebble material.

  5. Numerical simulation on pulverized coal combustion and NOx emissions in high temperature air from circulating fluidized bed

    NASA Astrophysics Data System (ADS)

    Zhu, Jianguo; Ouyang, Ziqu; Lu, Qinggang

    2013-06-01

    High temperature air combustion is a prospecting technology in energy saving and pollutants reduction. Numerical simulation on pulverized coal combustion and NOx emissions in high temperature air from circulating fluidized bed was presented. The down-fired combustor, taken as the calculation domain, has the diameter of 220 mm and the height of 3000 mm. 2 cases with air staging combustion are simulated. Compared the simulation results with experimental data, there is a good agreement. It is found that the combustion model and NOx formation model are applicable to simulate the pulverized coal combustion and NOx emissions in high temperature air from circulating fluidized bed. The results show that there is a uniform temperature profile along the axis of the down-fired combustor. The NOx emissions are lower than those of ordinary pulverized coal combustion, and the NOx emissions are 390 mg/m3 and 352 mg/m3 in Case 1 and Case 2, respectively. At the range of 300-600 mm below the nozzle, the NO concentration decreases, mainly resulting from some homogeneous reactions and heterogeneous reaction. NO concentration has a little increase at the position of 800 mm below the nozzle as the tertiary air supplied to the combustor at the position of 600 mm below the nozzle.

  6. Materials problems in fluidized bed combustion systems. Appendix 4: evaluation of boiler alloy specimens at General Electric Company. Final report

    SciTech Connect

    Not Available

    1980-05-01

    The results of post-test evaluations of certain boiler alloy specimens from corrosion tests conducted in the fluidized-bed combustion system at the Coal Research Establishment, Stoke Orchard, England are presented. Two tests, each of 1000 hours duration were conducted. Alloys included were Inconel 601, Inconel 617, Inconel 671, Hastelloy X, Haynes Alloy 188, and GE-2541 alloy. Specimen temperatures ranged from 649/sup 0/C (1200/sup 0/F) to 899/sup 0/C (1650/sup 0/F). Calcium sulfate deposits occurred on all specimens, regardless of whether they were situated in the combustion bed or in the free-board above it. In general, corrosion attack as measured by the thickness of affected metal below the deposit/scale, was greater in specimens located in the bed than in similar specimens tested at the same temperature above the bed. A dramatic example of this is the 160 to 225 microns average attack in specimens of Inconel 671 tested at 899/sup 0/C (1650/sup 0/F) in the bed compared to 18 microns in a specimen tested at the same temperature above the bed. In most instances the differences were much smaller, and in a few cases no difference was apparent. Inconel 601 showed greater attack at 760/sup 0/C (1400/sup 0/F) in the bed than at 843/sup 0/C (1550/sup 0/F). To a lesser extent, Inconel 617 specimens showed the same general trend. Hastelloy X and Haynes Alloy 188 specimens exhibited moderate attack (10 to 50 microns) at the temperatures at which they were tested. Specimens of the iron-chrome-aluminum-yttrium alloy, GE-2541, showed the least attack at 899/sup 0/C (1650/sup 0/F) of these alloys, both for specimens tested in and above the combustion bed. Inconel 671 specimens which were situated in the combustion bed showed very severe localized attack (pits) while many other areas of the same specimens exhibited no greater attack than specimens of other alloys.

  7. Numerical and experimental studies on effects of moisture content on combustion characteristics of simulated municipal solid wastes in a fixed bed.

    PubMed

    Sun, Rui; Ismail, Tamer M; Ren, Xiaohan; Abd El-Salam, M

    2015-05-01

    In order to reveal the features of the combustion process in the porous bed of a waste incinerator, a two-dimensional unsteady state model and experimental study were employed to investigate the combustion process in a fixed bed of municipal solid waste (MSW) on the combustion process in a fixed bed reactor. Conservation equations of the waste bed were implemented to describe the incineration process. The gas phase turbulence was modeled using the k-ε turbulent model and the particle phase was modeled using the kinetic theory of granular flow. The rate of moisture evaporation, devolatilization rate, and char burnout was calculated according to the waste property characters. The simulation results were then compared with experimental data for different moisture content of MSW, which shows that the incineration process of waste in the fixed bed is reasonably simulated. The simulation results of solid temperature, gas species and process rate in the bed are accordant with experimental data. Due to the high moisture content of fuel, moisture evaporation consumes a vast amount of heat, and the evaporation takes up most of the combustion time (about 2/3 of the whole combustion process). The whole bed combustion process reduces greatly as MSW moisture content increases. The experimental and simulation results provide direction for design and optimization of the fixed bed of MSW. PMID:25746177

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

    USGS Publications Warehouse

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

    1998-01-01

    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.

  9. Evaluation of alternative steam generator designs for Atmospheric Fluidized-Bed Combustion plants: Final report. [AFBC

    SciTech Connect

    Dunlop, W.

    1987-07-01

    The Atmospheric Fluidized Bed Combustion development program at the 20 MW pilot plant at TVA's Shawnee Station is addressing several design issues related to the scale-up requirements for utility application. These include use of overbed vs. underbed feed systems for coal, limestone, and recycled solids, load following and control design for reliable operation, and economies of scale. After initial screening of several alternate configurations, conceptual designs of AFBC mechanical overbed and underbed feed power plants in 1 x 200 MW and 2 x 500 MW sizes were prepared. These designs were assessed for efficiency, performance, resource requirements, capital cost and levelized busbar costs and compared to conventional pulverized coal units of similar size. The findings are that relative to the AFBC underbed feed plants, the AFBC overbed feed plant is about $70/kW less expensive at the 200 MW size, and $20/kW more expensive at the 2 x 500 MW size. Also, the capital costs of AFBC units range from $20/kW to $130/kW less than conventional PCF units and the potential exists for further reductions in AFBC capital costs as AFBC technology improves. Levelized busbar costs are essentially the same for both types and sizes of the AFBC units and for the conventional PCF units. Only one coal, Illinois number6 - a high sulfur bituminous coal - was initially evaluated. Subsequently, five additional coals - bituminous, subbituminous and lignite - and plant locations were evaluated. Current testing of less expensive coals is expected to confirm the fuel flexibility of the AFBC units which may result in corresponding reductions in levelized busbar costs. Utility industry confidence in AFBC has recently been expressed by the planned design and construction of fluidized bed units in 100 MW to 160 MW sizes for Colorado Ute Electric Association, Northern States Power Co. and TVA. 5 refs., 38 figs., 54 tabs.

  10. Fluidized-bed-combustion ash for the solidification and stabilization of a metal-hydroxide sludge.

    PubMed

    Knoll, K L; Behr-Andres, C

    1998-01-01

    Fluidized-bed-combustion (FBC) ash is a by-product from a developing technology for coal-fired power plants that will economically reduce air emissions to meet requirements of the Clean Air Act. FBC ash has physical and chemical properties similar to Portland cement, but only has moderate success as a pozzolan in concrete applications due to low compressive strengths. However, FBC ash has proven effective for use as a binder for the solidification and stabilization (S/S) of metal-bearing sludges. Physical and chemical characterization procedures were used to analyze FBC ash and a metal-bearing sludge obtained from a hazardous waste treatment facility to develop 12 different S/S mix designs. The mix designs consist of four binder designs to evaluate sludge-to-binder ratios of approximately 0, 0.5, and 1. Portland cement is used as a control binder to compare unconfined compressive strengths and Toxicity Characteristic Leaching Procedure (TCLP) analyses from different ratios of the FBC ash streams: fly ash, char, and spent bed material (SBM). Compressive strengths ranging from 84 lbs per square inch (psi) to 298 psi were obtained from various mix designs containing different sludge-to-ash ratios cured for 28 days. All the mix designs passed the TCLP. Recoveries from leaching for each metal were less than 5% for most mix designs. Results of unconfined compressive strengths, TCLP, and percent recovery calculations indicate that the mix design containing approximately a 1:1 ratio of fly ash to char-and-sludge is the best mix design for the S/S of the metal-bearing sludge. PMID:15655996

  11. Combustion of liquid paint wastes in fluidized bed boiler as element of waste management system in the paint factory

    SciTech Connect

    Soko, W.A.; Biaecka, B.

    1998-12-31

    In this paper the solution to waste problems in the paint industry is presented by describing their combustion in a fluidized bed boiler as a part of the waste management system in the paint factory. Based on the Cleaner Production idea and concept of integration of design process with a future exploitation of equipment, some modifications of the waste management scheme in the factory are discussed to reduce the quantity of toxic wastes. To verify this concept combustion tests of paint production wastes and cocombustion of paint wastes with coal in an adopted industrial boiler were done. Results of these tests are presented in the paper.

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

    NASA Technical Reports Server (NTRS)

    Horio, M.; Wen, C. Y.

    1976-01-01

    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.

  13. Land application uses of pressurized fluidized-bed combustion (PFBC) ash

    SciTech Connect

    Beeghly, J.H.; Dick, W.A.; Wolfe, W.

    1993-09-01

    Dry alkaline flue gas desulfurization by-products (dry lime and limestone FGD scrubber ashes) including the American Electric Power (AEP) Tidd PFBC bed and cyclone ash, are being evaluated for beneficial uses via land application for agriculture, mine reclamation, and soil stabilization in a 5 year study that began December, 1990. A 1989 Battelle Memorial Institute report had recommended that the highest priority in stimulating reuse of FGD by-products was the sponsoring of in-field research of coal combustion products generated from high sulfur midwestern coals to (a) better understand and quantify the leach rate, fate and transport of sulfates and trace metals and (b) demonstrate the level of protection necessary to build public acceptance of land-based reuses (1). The specific objectives of the demonstration project are as follows: To characterize the material generated from dry FGD processes; to demonstrate the utilization of dry FGD by-products as an soil amendment material on agricultural lands and on abandoned and active surface coal mines in Ohio; to demonstrate the use of dry FGD by-product as an engineering material for soil stabilization; to determine the quantities of dry FGD material than can be utilized in each of these applications; to determine the environmental and economic impact of utilizing the material.

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

    SciTech Connect

    Not Available

    1993-02-01

    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.

  15. Development of a high-temperature erosion monitor for FBC (fluidized bed combustion) heat exchanger tubes

    SciTech Connect

    Reimann, K.J.

    1990-05-01

    Metal wastage in tubing of heat exchangers used in fluidized bed combustion (FBC) could affect plant operation and threaten the successful development of FBC technology. Monitoring of such wastage during operation would be very beneficial. The development of a high-temperature erosion monitor was undertaken as part of a larger program to understand and ameliorate wastage processes. Two sensor principles, i.e., electromagnetic acoustic and piezoelectric transducers based on time-of-flight measurements, were evaluated. Spatial restrictions and high-energy requirements of electromagnetic acoustic transducers favored piezoelectric transducers as a prototype. Requirements for good coupling between sensor and tubing led to the exploration of two methods for accomplishing this task: pressure coupling and brazing. Initial disappointments with brazing led to the construction of a pressure-coupled transducer that was tested successfully to temperatures of up to 500{degree}C. A brazing method to bond the lithium niobate crystal to stainless steel was finally perfected, but will require additional work for brazing to ferritic steel. The prototype pressure-coupled transducer also needs more development to compensate for the expansion of components and oxidation of coupling surfaces. 3 refs., 15 figs., 1 tab.

  16. Availability of trace elements in solid waste from fluidized bed combustion of coal

    SciTech Connect

    Rope, S.K.; Jornitz, R.S.; Suhre, D.T.

    1987-12-01

    This report presents data on the inorganic constituents (major and trace elements) of coal and solid waste from a coal-fired facility on the Idaho National Engineering Laboratory (INEL) which uses the fluidized bed combustion process. Three factors were used to assess the potential environmental impacts of elements in coal waste: (1) the concentrations relative to those measured previously in surrounding soils of the INEL (the enrichment ratio); (2) the availability of elements from waste relative to soils; and (3) toxicity or essentiality to biota. Considering both enrichment and availability, Al, B, Be, Ca, Cr, Na, Mo, Se, Sr, and Ti are most likely to be affected in the local environment due to fly ash deposition and/or resuspension of FBC waste. Only B, Cr, Mo, and Se are likely to be of concern in terms of toxicity. The high concentrations of Cr and B in FBC waste are expected to be toxic to plants. Concentrations of Se and Mo present in FBC waste have been shown to produce levels in plants which can be toxic to herbivorous animals. 14 refs, 1 fig., 4 tabs.

  17. Technology assessment for an atmospheric fluidized-bed combustion demonstration plant

    SciTech Connect

    Siman-Tov, M; Jones, Jr, J E

    1980-01-01

    This study assesses the atmospheric fluidized-bed combustion (AFBC) technology with respect to design, construction, and operation of a demonstration power plant in the range of 150 to 250 MW(e) capacity and identifies the most critical research and development needs for the plant project. The general conclusion of these studies is that AFBC is feasible for large power plants and that it has a generally good potential for providing an economically and environmentally acceptable alternative to conventional coal-fired power plants. Several areas of technical uncertainty must, however, be resolved in order to ensure success of an AFBC demonstration plant project. Much of the existing data base for AFBC comes from small-scale test units, and much of it is still inconclusive. A number of operational and design problems exist that do not yet have conclusive answers. A focused research and development program aimed at the early resolution of these problems should be carried out to ensure successful construction and operation of the proposed AFBC demonstration plant and early commercialization of the technology. A large flexible feeding test facility designed to investigate the feeding problems and possibilities should be constructed. A materials-test facility is also needed for testing, evaluating and selecting materials, as well as demonstrating their long-term compatibility. An intermediate-size pilot plant with sufficient flexibility to test alternate solutions to the above-mentioned problems will considerably strengthen the demonstration program.

  18. Market Assessment and Technical Feasibility Study of Pressurized Fluidized Bed Combustion Ash Use

    SciTech Connect

    Bland, A.E.; Brown, T.H.

    1996-12-31

    Western Research Institute in conjunction with the Electric Power Research Institute, Foster Wheeler Energy International, Inc. and the U.S. Department of Energy Technology Center (METC), has undertaken a research and demonstration program designed to examine the market potential and the technical feasibility of ash use options for pressurized fluidized bed combustion (PFBC) ashes. The assessment is designed to address six applications, including: (1) structural fill, (2) road base construction, (3) supplementary cementing materials in portland cement, (4) synthetic aggregate, and (5) agricultural/soil amendment applications. Ash from low-sulfur subbituminous coal-fired Foster Wheeler Energia Oy pilot circulating PFBC tests in Karhula, Finland, and ash from the high-sulfur bituminous coal-fired American Electric Power (AEP) bubbling PFBC in Brilliant, Ohio, were evaluated in laboratory and pilot-scale ash use testing. This paper addresses the technical feasibility of ash use options for PFBC unit using low- sulfur coal and limestone sorbent (karhula ash) and high-sulfur coal and dolomite sorbents (AEP Tidd ash).

  19. Combustion characteristics of paper mill sludge in a lab-scale combustor with internally cycloned circulating fluidized bed.

    PubMed

    Shin, D; Jang, S; Hwang, J

    2005-01-01

    After performing a series of batch type experiments using a lab-scale combustor, consideration was given to the use of an internally cycloned circulating fluidized bed combustor (ICCFBC) for a paper mill sludge. Operation parameters including water content, feeding mass of the sludge, and secondary air injection ratio were varied to understand their effects on combustion performance, which was examined in terms of carbon conversion rate (CCR) and the emission rates of CO, C(x)H(y) and NO(x). The combustion of paper mill sludge in the ICCFBC was compared to the reaction mechanisms of a conventional solid fuel combustion, characterized by kinetics limited reaction zone, diffusion limited reaction zone, and transition zone. The results of the parametric study showed that a 35% water content and 60 g feeding mass generated the best condition for combustion. Meanwhile, areal mass burning rate, which is an important design and operation parameter at an industrial scale plant, was estimated by a conceptual equation. The areal mass burning rate corresponding to the best combustion condition was approximately 400 kg/hm(2) for 35% water content. The secondary air injection generating swirling flow enhanced the mixing between the gas phase components as well as the solid phase components, and improved the combustion efficiency by increasing the carbon conversion rate and reducing pollutant emissions. PMID:16009301

  20. 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...

  1. Influence of simulated MSW sizes on the combustion process in a fixed bed: CFD and experimental approaches.

    PubMed

    Sun, Rui; Ismail, Tamer M; Ren, Xiaohan; Abd El-Salam, M

    2016-03-01

    This work presents the effect of the simulated sizes of Municipal Solid Waste (MSW) on the combustion process in a fixed bed experimentally and numerically. The effect of temperature, gas emissions, flame front velocity and process rate are discussed for three different sizes of MSW: 10, 30, and 50 mm. The study found that for the operating conditions of the current model, when the diameter of particles is decreased, the bulk density of the material is increased, resulting in a decrease of convective heat transfer as well as combustion speed. As the diameter size of the material particles increase, the height of the post-combustion zone is increased, while the temperature in a high temperature area is decreased, due to the decrease in the material's bulk density and the excessive increase in porosity. Results also show that the average emission concentration of CO and CO2 decreases gradually with an increase in the particle diameter size. PMID:26750870

  2. Technical study on the possibilities of oil shale combustion in a fluidized bed furnace including cost estimates for a plant to be built

    NASA Astrophysics Data System (ADS)

    Kuehl, M.; Steller, P.

    1982-06-01

    The possibilities of oil shale combustion in a fluidized bed furnace were studied and the costs for a power plant were estimated. An overall concept of oil shale combustion in a fluidized bed furnace is drafted and the final plant size is established, allowing a scaling up of 200 t/hr steam. The concept was technically revised, resulting in a cost estimate of about 15% accuracy.

  3. Chemical composition of leachate of dairy manure mixed with fluidized bed combustion residue

    SciTech Connect

    Elrashidi, M.A.; Baligar, V.C.; Korcak, R.F.; Persaud, N.; Ritchey, K.D.

    1999-08-01

    This study was initiated to investigate the hypothesis that using fluidized bed combustion (FBC) residue to stabilize a dairy feedlot surface (DFS) could enhance element attenuation and minimize the environmental impact on water quality. The laboratory leaching experiment included FBC, dairy manure (DM), and DM/FBC treatments. The leaching process consisted of 10 weekly additions of distilled water, each of 460 mL. Using FBC with DM decreased the concentration of most elements (e.g., P, N, K, Ca, Al, Si, Fe, Mn, Cu, Zn, Pb, Cd, Co, Cr, Ni, As, and Se) in the leachate. A decrease ranging from 5.6 to 100% was obtained. The presence of high concentration of dissolved organic matter (DOM) is believed to enhance element attenuation by FBC minerals. Several mechanisms involved in this process are proposed: (1) formation of insoluble metal-organic complexes; (2) sorption of soluble organic and inorganic species on mineral surfaces; and (3) precipitation of soluble inorganic species. These mechanisms are discussed in relation to each of the measured elements. On the other hand, using FBC with DM appeared to increase the concentration of B, S, and Mg in the leachate. Reactions of DOM with FBC minerals to form soluble organic complexes were suggested to explain B and S increases. The increase in leached Mg could be attributed to the presence of SO{sub 4}{sup 2{minus}}. Their results provide evidence that using FBC to stabilize DFS has the advantage of immobilizing a large portion of most elements present in DM leachate.

  4. Emissions from biomass combustion in a fluidized bed combustor and gas cleanup system

    SciTech Connect

    Burton, B.; Lighty, J.S.; Inkley, D.; Eddings, E.; Overacker, D.; Davis, K.; Lee, C.; Sarofim, A.

    1999-07-01

    The University of Utah Department of Chemical and Fuels Engineering and Reaction Engineering International have designed and tested a fluidized bed for resource recovery in a Mars or lunar space station for feed streams consisting of inedible plant biomass and solid human waste. In conjunction with the combustor, the system has an extensive flue gas clean-up system to meet Spacecraft Maximum Allowable Concentrations (SMACs). This paper discusses the selection of a rich low-temperature combustion mode that minimizes the ash fusion problems with the high potassium feed and which generates sufficient unburned carbon monoxide to enable the reduction of NO. The components of the gas clean-up stream include: particle removal; HCl removal; NO{sub x} reduction; hydrocarbon and carbon monoxide destruction; sulfur capture; and a final gas polishing unit. Major developmental efforts were required to develop systems for trouble-free waste feeding and NO{sub x} reduction. The combustor is operated at temperatures below 700 C since the ash component of the hydroponically grown inedible biomass has a very low melting point. Low temperature operation results in high levels of CO and unburned hydrocarbons, which can be used as reducing agents for NO{sub x} in the downstream catalytic unit. This is more desirable than using ammonia, which is hazardous, and an expendable reagent that must be stored in sufficient quantity for the duration of a mission. The paper will discuss the results of an innovative catalyst system to reduce NO{sub x}, hydrocarbons, and CO. One important feature of this totally regenerative system is the potential reuse of potassium and sulfur captured in the ash for the hydroponic plant solution.

  5. Numerical and experimental studies on effects of moisture content on combustion characteristics of simulated municipal solid wastes in a fixed bed

    SciTech Connect

    Sun, Rui; Ismail, Tamer M.; Ren, Xiaohan; Abd El-Salam, M.

    2015-05-15

    Highlights: • The effects of moisture content on the burning process of MSW are investigated. • A two-dimensional mathematical model was built to simulate the combustion process. • Temperature distributions, process rates, gas species were measured and simulated. • The The conversion ratio of C/CO and N/NO in MSW are inverse to moisture content. - Abstract: In order to reveal the features of the combustion process in the porous bed of a waste incinerator, a two-dimensional unsteady state model and experimental study were employed to investigate the combustion process in a fixed bed of municipal solid waste (MSW) on the combustion process in a fixed bed reactor. Conservation equations of the waste bed were implemented to describe the incineration process. The gas phase turbulence was modeled using the k–ε turbulent model and the particle phase was modeled using the kinetic theory of granular flow. The rate of moisture evaporation, devolatilization rate, and char burnout was calculated according to the waste property characters. The simulation results were then compared with experimental data for different moisture content of MSW, which shows that the incineration process of waste in the fixed bed is reasonably simulated. The simulation results of solid temperature, gas species and process rate in the bed are accordant with experimental data. Due to the high moisture content of fuel, moisture evaporation consumes a vast amount of heat, and the evaporation takes up most of the combustion time (about 2/3 of the whole combustion process). The whole bed combustion process reduces greatly as MSW moisture content increases. The experimental and simulation results provide direction for design and optimization of the fixed bed of MSW.

  6. Performance improvement of a converted fluid bed boiler (from traveling grate type) for agro waste combustion -- A case study

    SciTech Connect

    Sethumadhavan, R.; Karthikeyan, G.; Raviprakash, A.V.; Vasudevan, R.

    1997-12-31

    This paper investigates the operational difficulty encountered while operating a fluid bed boiler--which was earlier serving with a traveling grate for agrowaste combustion. This boiler, although operating on fluid bed technology principle, could not produce required combustion efficiency while burning any of the agrowastes such as rice husk, de-oiled bran, ground nut shell, etc. While carrying out the performance assessment study, it was found that, this inefficient combustion was mainly due to the improper operating parameters and partly due to incorrect furnace configuration. The drawbacks of the system have been attended to and set right incurring a very minor expenditure. This has led to an annual fuel saving of approximately US $40,000. The major results achieved are: (1) boiler thermal efficiency increased from 66--73%; (2) boiler was loaded uniformly and on-time operation has increased to 100% from earlier 60%; (3) boiler shut down time due to operational problems has come down from 35 hours per month to 15 hours per month; (4) very effective dust collection system was achieved resulting in reduced ID fan erosion; and (5) an annual saving of US $100,000 (both direct and indirect) was achieved.

  7. Energy and environmental research emphasizing low-rank coal -- Task 3.8, Pressurized fluidized-bed combustion

    SciTech Connect

    Mann, M.D.; Henderson, A.K.; Swanson, M.L.

    1995-03-01

    The goal of the PFBC activity is to generate fundamental process information that will further the development of an economical and environmentally acceptable second-generation PFBC. The immediate objectives focus on generic issues, including the performance of sulfur sorbents, fate of alkali, and the Resource Conservation and Recovery Act (RCRA) heavy metals in PFBC. A great deal of PFBC performance relates to the chemistry of the bed and the contact between gas and solids that occurs during combustion. These factors can be studied in a suitably designed bench-scale reactor. The present studies are focusing on the emission control strategies applied in the bed, rather than in hot-gas cleaning. Emission components include alkali and heavy metals in addition to SO{sub 2}, NO{sub x}, N{sub 2}O, and CO. The report presents: a description of the pressurized fluidized-bed reactor (PFBR); a description of the alkali sampling probe; shakedown testing of the bench-scale PFBR; results from alkali sampling; results from sulfur sorbent performance tests; and results from refuse-derived fuel and lignite combustion tests.

  8. Acidic soil amendment with a magnesium-containing fluidized bed combustion by-product

    SciTech Connect

    Stehouwer, R.C.; Dick, W.A.; Sutton, P.

    1999-02-01

    Removal of SO{sub 2} from the emissions of coal-fired boilers produces by-products that often consist of CaSO{sub 4}, residual alkalinity, and coal ash. These by-products could be beneficial to acidic soils because of their alkalinity and the ability of gypsum (CaSO{sub 4}{center{underscore}dot}2H{sub 2}O) to reduce Al toxicity in acidic subsoils. A 3-yr field experiment was conducted to determine the liming efficacy of a fluidized bed combustion boiler by-product (FBC) that contained 129 g Mg kg{sup {minus}1} as CaMg(CO{sub 3}){sub 2} and MgO and its effects on surface and subsurface soil chemistry. The FBC was mixed in the surface 10 cm of two acidic soils (Wooster silt loam, an Oxyaquic Fragiudalf, and Coshocton silt loam, an Aquultic Hapludalf) at rates of 0, 0.5, 1, and 2 times each soil's lime requirement (LR). Soils were sampled in 10-cm increments to depths ranging from 20 to 110 cm, and corn (Zea mays L.) and alfalfa (Medicago sativa L.) were grown. Application of Mg-FBC increased alfalfa yields in all six site-years, whereas it had no effect on corn grain yield in five site-years and decreased grain yield in one site-year. Plant tissue concentrations of Mg, S, and Mo were increased by Mg-FBC, while most trace elements were either unaffected or decreased. Application of Mg-FBC at one or two times LR increased surface soil pH to near 7 within 1 wk. Although surface soil pH remained near 7 for 2 yr, there was minimal effect on subjacent soil pH. Application of Mg-FBC increased surface soil concentrations of Ca, Mg, and S, which promoted downward movement of Mg and SO{sub 4}. This had different effects on subsoil chemistry in the two soils: in the high-Ca-status Wooster subsoil, exchangeable Ca was decreased and exchangeable Al was increased, whereas in the high-Al-status Coshocton subsoil, exchangeable Al was decreased and exchangeable Mg was increased. The Mg-FBC was an effective liming material and, because of the presence of both Mg and SO{sub 4}, may be

  9. Experimental investigation of wood combustion in a fixed bed with hot air

    SciTech Connect

    Markovic, Miladin Bramer, Eddy A.; Brem, Gerrit

    2014-01-15

    Highlights: • Upward combustion is a new combustion concept with ignition by hot primary air. • Upward combustion has three stages: short drying, rapid devolatilization and char combustion. • Variation of fuel moisture and inert content have little influence on the combustion. • Experimental comparison between conventional and upward combustion is presented. - Abstract: Waste combustion on a grate with energy recovery is an important pillar of municipal solid waste (MSW) management in the Netherlands. In MSW incinerators fresh waste stacked on a grate enters the combustion chamber, heats up by radiation from the flame above the layer and ignition occurs. Typically, the reaction zone starts at the top of the waste layer and propagates downwards, producing heat for drying and devolatilization of the fresh waste below it until the ignition front reaches the grate. The control of this process is mainly based on empiricism. MSW is a highly inhomogeneous fuel with continuous fluctuating moisture content, heating value and chemical composition. The resulting process fluctuations may cause process control difficulties, fouling and corrosion issues, extra maintenance, and unplanned stops. In the new concept the fuel layer is ignited by means of preheated air (T > 220 °C) from below without any external ignition source. As a result a combustion front will be formed close to the grate and will propagate upwards. That is why this approach is denoted by upward combustion. Experimental research has been carried out in a batch reactor with height of 4.55 m, an inner diameter of 200 mm and a fuel layer height up to 1 m. Due to a high quality two-layer insulation adiabatic conditions can be assumed. The primary air can be preheated up to 350 °C, and the secondary air is distributed via nozzles above the waste layer. During the experiments, temperatures along the height of the reactor, gas composition and total weight decrease are continuously monitored. The influence of

  10. Modeling of fluidized-bed combustion of coal: Phase II, final reports. Volume III. Model predictions and results

    SciTech Connect

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

    1980-10-01

    This document is the third of a seven volume series of our Phase II Final Report. This volume deals with parametric studies carried out using the FBC model. A comparison with available pilot plant data is included where such data are available. This volume in essence documents model performance; describing predictions on bubble growth, combustion characteristics, sulfur capture, heat transfer and related parameters. The model has approximately forty input variables which are at the disposal of the user. The user has the option to change a few or all of these input variables. In the parametric studies reported here, a large number of input variables whose variation is less critical to the predicted results, were maintained constant at the default values. On the other hand, those parameters whose selection is very important in design and operation of the FBC's were varied in suitable operating regions. The chief among such parameters are: bed temperature, coal feed size distribution (2 parameters), average bed-sorbent size, calcium to sulfur molar ratio, superficial velocity, excess air fraction, and bed weight (or bed height). The computations for obtaining the parametric relationships are based upon selection of a geometrical design for the combustor. Bed cross-section is 6' x 6', bed height is 4', and the freeboard height is 16'. The heat transfer tubes have 2'' OD, a pitch of 10'', and are located on an equilateral triangle pattern. The air distributor is a perforated plate with 0.1'' diameter holes on a rectangular grid with 0.75'' center-to-center spacing.

  11. Dispersion and co-combustion studies for disposal of agro-industrial effluents in bubbling fluidized bed

    SciTech Connect

    Miccio, F.

    1997-12-31

    The present work was developed in the frame of a collaboration between CNR/Istituto Ricerche Combustione, University of Parma and ENEA. It was aimed at exploiting and recovering the thermal energy from liquid effluents and solid wastes derived from typical Italian manufacturing of agro-industrial companies. This paper focuses on an organic sludge that is obtained as a residue during steam concentration of waste water from alcohol production in distilleries. This sludge has a very low calorific value and cannot be directly used in a combustion process. The first objective was to turn the sludge into a coal/waste/water mixture, easy to prepare and to burn on site in a bubbling fluidized combustor. To do so, some preliminary runs were carried out on a significant experimental scale by employing the 2100 kW{sub t} FBC-370 pre-pilot facility and by feeding underbed a South African coal/dry residue/water mixture with a maximum particle size of 1 mm. Very satisfactory values of co-combustion efficiency (i.e., larger than 98%), were attained as a function of the dispersing air velocity. It was proven that the mechanism of combustion passes through the formation of carbon-sand aggregates and tiny carbon deposits on bed sand particles. Another outcome was that pumping the mixture directly into the bed without any atomization is feasible and favorable from the point of view of co-combustion efficiency. Therefore, a second objective was to investigate aggregate formation as a result of mixture injection into the hot bed. This has been pursued through a review of the fundamental aspects underlying the behavior of a liquid issuing from an orifice. Two simple approaches, one based on Scheele and Meister`s (1968) results and the other one based on a balance of force moments, were followed. These two approaches provided two different equations to predict the diameter of a drop that detaches from the injection nozzle. Furthermore, aggregate formation was investigated through the set

  12. Combustion and NO emission of high nitrogen content biomass in a pilot-scale vortexing fluidized bed combustor.

    PubMed

    Qian, F P; Chyang, C S; Huang, K S; Tso, Jim

    2011-01-01

    The combustion of biomass of various nitrogen contents and its NO emission were investigated experimentally in this study. All the experiments were conducted in an I.D. 0.45 m pilot-scale vortexing fluidized bed combustor (VFBC). Rice husk, corn, and soybean were used as feeding materials. Urea was added into the feeding materials for the purpose of adjusting nitrogen content. The effects of various operating parameters on NO emission, such as bed temperature, excess air ratio, and flow rate of secondary air, were investigated. The effects of nitrogen content of fuels on NO emissions were also investigated by using the mixtures of rice husk/soybean, rice husk/urea, corn/soybean, and corn/urea in various weight ratios. The NO concentrations at various positions in the combustor were sampled and recorded. The experimental results show that most nitric oxide is formed at just above the bed surface. Temperature and excess air ratio are the major operating parameters for NO emission. For biomass with high nitrogen content, NO emission decreases with excess air, and increases with bed temperature. Compared with char-N, volatile-N is the more dominant reactant source for NO emission. PMID:20800476

  13. Pulsed atmospheric fluidized bed combustion. Technical progress report, April 1992--June 1992

    SciTech Connect

    Not Available

    1992-08-01

    The general specifications for a Pulsed Atmospheric Fluidized Bed Combustor Design Report (PAFBC) plant are presented. The design tasks for the PAFBC are described in the following areas: Coal/Limestone preparation and feed system; pulse combustor; fluidized bed; boiler parts; and ash handling system.

  14. Circulating fluidized bed combustion product addition to acid soil: alfalfa (Medicago sativa L.) composition and environmental quality.

    PubMed

    Chen, Liming; Dick, Warren A; Kost, David

    2006-06-28

    To reduce S emissions, petroleum coke with a high concentration of S was combusted with limestone in a circulating fluidized bed (CFB) boiler. The combustion process creates a bed product that has potential for agricultural uses. This CFB product is often alkaline and enriched in S and other essential plant nutrients, but also contains high concentrations of Ni and V. Agricultural land application of CFB product is encouraged, but little information is available related to plant responses and environmental impacts. CFB product and agricultural lime (ag-lime) were applied at rates of 0, 0.5, 1.0, and 2.0 times the soil's lime requirement (LR) to an acidic soil (Wooster silt loam). The 2.0x LR application rate of CFB product was equivalent to 67.2 Mg ha(-1). Alfalfa yield was increased 4.6 times by CFB product and 3.8 times by ag-lime compared to untreated control. Application of CFB product increased the concentration of V in soil and alfalfa tissue, but not in soil water, and increased the concentration of Ni in soil and soil water, but not in alfalfa tissue. However, these concentrations did not reach levels that might cause environmental problems. PMID:16787025

  15. Studies of Alkali Sorption Kinetics for Pressurized Fluidized Bed Combustion by High Pressure Mass Spectrometry

    SciTech Connect

    Wolf, K.J.; Willenborg, W.; Fricke, C.; Prikhodovsky, A.; Hilpert, K.; Singheiser, L.

    2002-09-20

    This work describes the first approach to use High Pressure Mass Spectrometry (HPMS) for the quantification and analysis of alkali species in a gas stream downstream a sorbent bed of different tested alumosilicates.

  16. Modeling of combustion of low grade lignites in fluidized beds with heat extraction

    SciTech Connect

    Mancuhan, E.; Oezyl, E.

    1999-07-01

    A computerized model was developed for any low rank coal with a known particle size distribution and mass fraction. When the coal is fed into the bed, the volatile matter is assumed to be released instantaneously and a new particle size distribution is achieved within the bed. The effect of elutriation and chemical reactions are also taken into account. The model developed investigates the effect of excess air on elutriation, particle size distribution of the semi-coke, and the mass fraction values within the bed at steady state conditions. The excess air ranged from 1 to 1.48. The model also takes into account the effect of coal type on the bed temperature. As is already known, temperature may vary significantly from type to type in the low quality coal range, much more than in the high quality coal types. The results of the model simulation studies are compared with a limited amount of experimental work available for Turkish lignites. The agreement between the model prediction and the experimental data is reasonably good. Closer to the distributor plate, the bed temperature prediction of the model is low, but agreement improves as the active bed surface is reached. The results obtained from the model are presented for feed air temperatures of 300, 400, and 500 K for Seyitoemer lignite. If 60% of the desired heat is extracted from the active bed, the optimum results can be obtained. Under optimum conditions, 70% of the volatile matter is burned within the active bed and the remainder of the freeboard.

  17. Modeling of fluidized-bed combustion of coal: Phase II, final reports. Volume II. Detailed description of the model

    SciTech Connect

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

    1980-10-01

    This document is the second of a seven volume series of our Phase II Final Report. This volume deals with detailed descriptions of the structure of each program member (subroutines and functions), the interrelation between the members of a submodel, and the interrelation between the various submodels as such. The systems model for fluidized bed combustors (FBC-II) consists of a systematic combination of the following interrelated areas: fluid mechanics and bubble growth, char combustion and associated kinetics for particle burnout, sulfur capture, NO/sub x/ formation and reduction, freeboard reactions, and heat transfer. Program outline is shown in Figure 1.1. Input variables (supplied by the user are inspected to check that they lie inside the allowed range of values and are input to the various routines as needed. The necessary physical and fluid mechanical properties are calculated and utilized in estimating char combustion and sulfur capture in the bed and the freeboard. NO/sub x/ and CO emissions are estimated by taking into account all relevant chemical reactions. A material and energy balance is made over the bed. Figure 1.1 shows a block diagram of the systems program. In this diagram, the overall structure of the FBC program is illustrated in terms of the various submodels that together constitute the systems program. A more detailed outline of the systems program is shown in Figure 1.2. In this figure, all important subroutine members of the FBC program are shown, and their linkage to each other, as well as to the main program is indicated. A description of the exact sequence in which these various routines are called at time of program execution is provided in Chapter 8 under the executive routine MAIN.

  18. High-temperature-staged fluidized-bed combustion (HITS), bench scale experimental test program conducted during 1980. Final report

    SciTech Connect

    Anderson, R E; Jassowski, D M; Newton, R A; Rudnicki, M L

    1981-04-01

    An experimental program was conducted to evaluate the process feasibility of the first stage of the HITS two-stage coal combustion system. Tests were run in a small (12-in. ID) fluidized bed facility at the Energy Engineering Laboratory, Aerojet Energy Conversion Company, Sacramento, California. The first stage reactor was run with low (0.70%) and high (4.06%) sulfur coals with ash fusion temperatures of 2450/sup 0/ and 2220/sup 0/F, respectively. Limestone was used to scavenge the sulfur. The produced low-Btu gas was burned in a combustor. Bed temperature and inlet gas percent oxygen were varied in the course of testing. Key results are summarized as follows: the process was stable and readily controllable, and generated a free-flowing char product using coals with low (2220/sup 0/F) and high (2450/sup 0/F) ash fusion temperatures at bed temperatures of at least 1700/sup 0/ and 1800/sup 0/F, respectively; the gaseous product was found to have a total heating value of about 120 Btu/SCF at 1350/sup 0/F, and the practicality of cleaning the hot product gas and delivering it to the combustor was demonstrated; sulfur capture efficiencies above 80% were demonstrated for both low and high sulfur coals with a calcium/sulfur mole ratio of approximately two; gasification rates of about 5,000 SCF/ft/sup 2/-hr were obtained for coal input rates ranging from 40 to 135 lbm/hr, as required to maintain the desired bed temperatures; and the gaseous product yielded combustion temperatures in excess of 3000/sup 0/F when burned with preheated (900/sup 0/F) air. The above test results support the promise of the HITS system to provide a practical means of converting high sulfur coal to a clean gas for industrial applications. Sulfur capture, gas heating value, and gas production rate are all in the range required for an effective system. Planning is underway for additional testing of the system in the 12-in. fluid bed facility, including demonstration of the second stage char burnup

  19. Use of fluidized bed combustion by-products for liners and alkali substitutes. Technical report, March 1--May 31, 1995

    SciTech Connect

    Paul, B.C.; Esling, S.; Pisani, F.; Wells, T.

    1995-12-31

    Fluidized Bed Combustion of coal eliminates most emissions of S and N oxides but produces sizable volumes of a solid residue that EPA may require to be placed in capped and lined landfills. Fluidized Bed Combustors are one of the most promising growth markets for Illinois coal and imposing cap and liner requirements may make the technology uneconomic. Fluidized Bed residues are cementlike and when mixed with soil, produce a material as impermeable as the clay liners used at landfills. This project will demonstrate that the residues can be mixed with soils by regular construction equipment and used in place of clays as liner material. The demonstration cap will cover an area of 7 acres and will prevent water infiltration into acid producing material. Baseline studies of Briar Creek indicate that the water is now highly degraded by acid drainage. Construction delays have enhanced the data collected on Briar Creek by allowing monitoring to continue through major seasonal changes without any effects attributable to the FBC ash. Materials needed to place the wells and lysimeters have been obtained. A contractor will build and deliver a mobile foam generator and spray to the field to demonstrate fugitive dust control from FBC fly ash (dust problem is one key barrier to more widespread use of FBC ash).

  20. Experimental investigation of wood combustion in a fixed bed with hot air.

    PubMed

    Markovic, Miladin; Bramer, Eddy A; Brem, Gerrit

    2014-01-01

    Waste combustion on a grate with energy recovery is an important pillar of municipal solid waste (MSW) management in the Netherlands. In MSW incinerators fresh waste stacked on a grate enters the combustion chamber, heats up by radiation from the flame above the layer and ignition occurs. Typically, the reaction zone starts at the top of the waste layer and propagates downwards, producing heat for drying and devolatilization of the fresh waste below it until the ignition front reaches the grate. The control of this process is mainly based on empiricism. MSW is a highly inhomogeneous fuel with continuous fluctuating moisture content, heating value and chemical composition. The resulting process fluctuations may cause process control difficulties, fouling and corrosion issues, extra maintenance, and unplanned stops. In the new concept the fuel layer is ignited by means of preheated air (T>220 °C) from below without any external ignition source. As a result a combustion front will be formed close to the grate and will propagate upwards. That is why this approach is denoted by upward combustion. Experimental research has been carried out in a batch reactor with height of 4.55 m, an inner diameter of 200 mm and a fuel layer height up to 1m. Due to a high quality two-layer insulation adiabatic conditions can be assumed. The primary air can be preheated up to 350 °C, and the secondary air is distributed via nozzles above the waste layer. During the experiments, temperatures along the height of the reactor, gas composition and total weight decrease are continuously monitored. The influence of the primary air speed, fuel moisture and inert content on the combustion characteristics (ignition rate, combustion rate, ignition front speed and temperature of the reaction zone) is evaluated. The upward combustion concept decouples the drying, devolatilization and burnout phase. In this way the moisture and inert content of the waste have almost no influence on the combustion

  1. Combustion of Biosolids in a Bubbling Fluidized Bed, Part 1: Main Ash-Forming Elements and Ash Distribution with a Focus on Phosphorus

    PubMed Central

    2014-01-01

    This is the first in a series of three papers describing combustion of biosolids in a 5-kW bubbling fluidized bed, the ash chemistry, and possible application of the ash produced as a fertilizing agent. This part of the study aims to clarify whether the distribution of main ash forming elements from biosolids can be changed by modifying the fuel matrix, the crystalline compounds of which can be identified in the raw materials and what role the total composition may play for which compounds are formed during combustion. The biosolids were subjected to low-temperature ashing to investigate which crystalline compounds that were present in the raw materials. Combustion experiments of two different types of biosolids were conducted in a 5-kW benchscale bubbling fluidized bed at two different bed temperatures and with two different additives. The additives were chosen to investigate whether the addition of alkali (K2CO3) and alkaline-earth metal (CaCO3) would affect the speciation of phosphorus, so the molar ratios targeted in modified fuels were P:K = 1:1 and P:K:Ca = 1:1:1, respectively. After combustion the ash fractions were collected, the ash distribution was determined and the ash fractions were analyzed with regards to elemental composition (ICP-AES and SEM-EDS) and part of the bed ash was also analyzed qualitatively using XRD. There was no evidence of zeolites in the unmodified fuels, based on low-temperature ashing. During combustion, the biosolid pellets formed large bed ash particles, ash pellets, which contained most of the total ash content (54%–95% (w/w)). This ash fraction contained most of the phosphorus found in the ash and the only phosphate that was identified was a whitlockite, Ca9(K,Mg,Fe)(PO4)7, for all fuels and fuel mixtures. With the addition of potassium, cristobalite (SiO2) could no longer be identified via X-ray diffraction (XRD) in the bed ash particles and leucite (KAlSi2O6) was formed. Most of the alkaline-earth metals calcium and

  2. A re-appraisal of wood-fired combustion.

    PubMed

    McIlveen-Wright, D R; Williams, B C; McMullan, J T

    2001-02-01

    Targets for a considerable increase in electricity generation from renewables have been set in order to reduce greenhouse gas emissions and fossil fuel dependence. Extensive planting of willow, poplar and alder as energy crops has been planned for power generation plants which use wood as the fuel. The current trend is to use gasification or pyrolysis technology, but alternatively a case may be made for wood combustion, if wood becomes readily available. A range of wood-fired circulating fluidised bed combustion (CFBC) plants, using from 10 to 10,000 dry tonne equivalent (DTE)/day, was examined using the ECLIPSE process simulation package. Various factors, such as wood moisture content, harvest yield, afforestation level (AL) and discounted cash flow rate (DCF) were investigated to test their influence on the efficiency and the economics of the systems. Steam cycle conditions and wood moisture content were found to have the biggest effects on the system efficiencies; DCF and AL had the largest influences on the economics. Plants which could handle more than 500 dry tonnes/day could be economically viable; those using more than 1000 dry tonnes wood/day could be competitive with large-scale, conventional coal-fired plants, if sufficient wood were available. PMID:11198168

  3. Pulsed atmospheric fluidized bed combustion. Quarterly report, July 1--September 30, 1995

    SciTech Connect

    1995-12-31

    The report summarizes progress in design, fabrication, and construction activities. Progress on the fluid bed combustor, piping, fuel feeding system, ash system, and the control and instrumentation design is described. The report lists the construction activities completed during this quarter which included bed tubes installation, fan inlet flow measuring duct, bag filter, silencers for roots blowers, electric power cabling connections, light distributor panel and transformer installation inside the control panel, steam/water recirculation piping, fine coal receiving vent filter, and partial painting of ash silo and boiler.

  4. Modeling of circulating fluised beds for post-combustion carbon capture

    SciTech Connect

    Lee, A.; Shadle, L.; Miller, D.

    2011-01-01

    A compartment based model for a circulating fluidized bed reactor has been developed based on experimental observations of riser hydrodynamics. The model uses a cluster based approach to describe the two-phase behavior of circulating fluidized beds. Fundamental mass balance equations have been derived to describe the movement of both gas and solids though the system. Additional work is being performed to develop the correlations required to describe the hydrodynamics of the system. Initial testing of the model with experimental data shows promising results and highlights the importance of including end effects within the model.

  5. APPLICATION OF ADVANCED TECHNOLOGY FOR NOX CONTROL: ALTERNATE FUELS AND FLUIDIZED-BED COAL COMBUSTION

    EPA Science Inventory

    The paper discusses the effect of alternate fuels and fluidized coal combustion in controlling the emission of nitrogen oxides (NOx). The current trend in energy use in the U.S. is toward greater use of coal and coal derived fuels, and on ensuring that these fuels are produced an...

  6. Leaching behavior and possible resource recovery from air pollution control residues of fluidized bed combustion of municipal solid waste

    SciTech Connect

    Abbas, Z.; Andersson, B.A.; Steenari, B.M.

    1999-07-01

    Ash residues are generated at several points during combustion of municipal solid waste (MSW), i.e., in cyclones, electrostatic precipitators and fabric filters. Such residues are of a complex physical and chemical nature and are often enriched in soluble salts and heavy metals such as Pb, Cd and Zn. Fluidized bed combustion (FBC) of MSW is a relatively new technique and very little information is available about the leaching behavior of its residues. In this study, the total elemental composition, mineralogy and leaching behavior of cyclone and bag-house filter ashes from a bubbling fluidized bed (BFB) boiler fired with municipal solid waste have been investigated. In addition, the possibilities of recovery heavy metals from these ashes were studied. The long-term leaching behavior of the ash constituents was evaluated using a two-step batch leaching test known as the CEN-test, whereas short and medium term leaching behavior was evaluated using a Column test. The extraction of elements from cyclone and filter ashes with various acidic solutions was also investigated. The leaching behavior of acid washed ashes was evaluated using the CEN test. The cyclone ash was mainly composed of aluminosilicate minerals, whereas the filter ash consisted of chlorides and hydroxides of alkali and alkaline earth metals. The concentration of heavy metals such as Zn, Cu, Cd and Pb was higher in the filter ash than in the cyclone ash. The leached amounts of sulfates and Pb from the cyclone ash decreased with leaching test contact time, indicating the formation of secondary mineral phases. Large amounts of chlorides, sulfates, Ca, Cu and Pb were leached from the filter ash. Acid extraction removed large amounts ({gt}50%) of Zn, Pb and Cu from the filter ash and approximately 56% of the total amount of Zn present in the cyclone ash. An efficient removal of heavy metal species from these types of ashes can probably be achieved by application of a recycling or multi-step process.

  7. DISPOSAL OF FLUIDIZED BED COMBUSTION ASH IN AN UNDERGROUND MINE TO CONTROL ACID MINE DRAINAGE AND SUBSIDENCE

    SciTech Connect

    Unknown

    1999-01-01

    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 feasibility of the approach (i.e. % void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). This document reports on progress made during Phase III. The report is divided into four major sections. The first deals with the Hydraulic Injection component. This section of the report reports on progress and milestones associated with the grouting activities of the project. The Phase III tasks of Economic Analysis and Regulatory Analysis is covered under this section. The second component is Pneumatic Injection. This section reports on progress made towards completing the demonstration project. The Water Quality component involves background monitoring of water quality and precipitation at the Phase III (Longridge) mine site. The last component involves evaluating the migration of contaminants through the grouted mine. A computer model has been developed in earlier phases and will model the flow of water in and around the grouted Longridge mine.

  8. DISPOSAL OF FLUIDIZED BED COMBUSTION ASH IN AN UNDERGROUND MINE TO CONTROL ACID MINE DRAINAGE AND SUBSIDENCE

    SciTech Connect

    Unknown

    1999-07-01

    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 feasibility of the approach (i.e. % void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). This document reports on progress made during Phase III. The report is divided into three major sections. The first deals with the Hydraulic Injection component. This section of the report describes the progress and milestones associated with the grouting activities of the project. The Phase III tasks of Economic Analysis and Regulatory Analysis is covered under this section. The second component is Pneumatic Injection. This section reports on progress made towards completing the demonstration project. The last component involves evaluating the migration of contaminants through the grouted mine. A computer model has been developed in earlier phases and will model the flow of water in and around the grouted Longridge mine.

  9. DISPOSAL OF FLUIDIZED BED COMBUSTION ASH IN AN UNDERGROUND MINE TO CONTROL ACID MINE DRAINAGE AND SUBSIDENCE

    SciTech Connect

    Unknown

    1999-04-01

    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 feasibility of the approach (i.e. % void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). This document reports on progress made during Phase III. The report is divided into three major sections. The first deals with the Hydraulic Injection component. This section of the report describes the progress and milestones associated with the grouting activities of the project. The Phase III tasks of Economic Analysis and Regulatory Analysis is covered under this section. The second component is Pneumatic Injection. This section reports on progress made towards completing the demonstration project. The last component involves evaluating the migration of contaminants through the grouted mine. A computer model has been developed in earlier phases and will model the flow of water in and around the grouted Longridge mine.

  10. DISPOSAL OF FLUIDIZED BED COMBUSTION ASH IN AN UNDERGROUND MINE TO CONTROL ACID MINE DRAINAGE AND SUBSIDENCE

    SciTech Connect

    Unknown

    2000-04-01

    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 feasibility of the approach (i.e. % void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). This document reports on progress made during Phase III. The report is divided into three major sections. The first deals with the Hydraulic Injection component. This section of the report describes the progress and milestones associated with the grouting activities of the project. The Phase III tasks of Economic Analysis and Regulatory Analysis is covered under this section. The second component is Pneumatic Injection. This section reports on progress made towards completing the demonstration project. The last component involves evaluating the migration of contaminants through the grouted mine. A computer model has been developed in earlier phases and will model the flow of water in and around the grouted Longridge mine.

  11. DISPOSAL OF FLUIDIZED BED COMBUSTION ASH IN AN UNDERGROUND MINE TO CONTROL ACID MINE DRAINAGE AND SUBSIDENCE

    SciTech Connect

    Unknown

    2000-01-01

    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 feasibility of the approach (i.e. % void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). This document reports on progress made during Phase III. The report is divided into three major sections. The first deals with the Hydraulic Injection component. This section of the report describes the progress and milestones associated with the grouting activities of the project. The Phase III tasks of Economic Analysis and Regulatory Analysis is covered under this section. The second component is Pneumatic Injection. This section reports on progress made towards completing the demonstration project. The last component involves evaluating the migration of contaminants through the grouted mine. A computer model has been developed in earlier phases and will model the flow of water in and around the grouted Longridge mine.

  12. Options and economics for fluidized bed combustion of pulp and paper mill sludge and residuals

    SciTech Connect

    Ferris, J.M.

    1995-12-31

    Although only the tip of the iceberg in terms of examples, these case studies provide some indication of the variety of successful sludge combustion projects which can be implemented. The variables we have discussed in this paper vary significantly with each case, yet each of these projects is economically and environmentally favorable to the mill. There is no easy formula for identifying all of the factors which will {open_quotes}make or break{close_quotes} a sludge combustion project. Sludge quality and quantity are certainly key variables, but the economics depend upon the combination of numerous other variables as well. As managers, consultants and suppliers in the pulp and paper industry, the first step to take is to recognize that the sludge and rejects that you typically think of as an economic and environmental liability may, in fact, be an energy asset which can be disposed of through combustion. The next step, although not quite as simple, is to identify and analyze the variables and define the economic impact.

  13. A model of coal particle drying in fluidized bed combustion reactor

    SciTech Connect

    Komatina, M.; Manovic, V.; Saljnikov, A.

    2007-02-15

    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.

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

    SciTech Connect

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

    1984-04-01

    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.

  15. Pulsed atmospheric fluidized bed combustion. Technical progress report, January 1, 1993--March 31, 1993

    SciTech Connect

    Not Available

    1993-05-01

    As reported in previous quarterly reports, the fabrication of the fluid bed vessel, hot cyclone, coal handling system components, and coal/limestone feed systems is underway. Procurement of long lead time items was initiated in October 1992, and.deliveries are being made on schedule. In this quarterly period the following design tasks were accomplished. Mass and energy balance review and optimization; system operation calibrations; piping pressure drop design calculations; and pipe sizing and layout drawings.

  16. The influence of temperature on limestone sulfation and attrition under fluidized bed combustion conditions

    SciTech Connect

    Montagnaro, Fabio; Salatino, Piero; Scala, Fabrizio

    2010-04-15

    The influence of temperature on attrition of two limestones during desulfurization in a fluidized bed reactor was investigated. Differences in the microstructure of the two limestones were reflected by a different thickness of the sulfate shell formed upon sulfation and by a different value of the ultimate calcium conversion degree. Particle attrition and fragmentation were fairly small under moderately bubbling fluidization conditions for both limestones. An increase of temperature from 850 C to 900 C led to an increase of the attrition rate, most likely because of a particle weakening effect caused by a faster CO{sub 2} evolution during calcination. This weakening effect, however, was not sufficiently strong to enhance particle fragmentation in the bed. The progress of sulfation, associated to the build-up of a hard sulfate shell around the particles, led in any case to a decrease of the extent of attrition. Sulfation at 900 C was less effective than at 850 C, and this was shown to be related to the porosimetric features of the different samples. (author)

  17. Heavy metal behavior during circulating fluidized bed combustion of willow (Salix)

    SciTech Connect

    Lind, T.; Kauppinen, E.I.; Nilsson, K.; Sfiris, G.; Maenhaut, W.; Huggins, F.E.

    1999-07-01

    The behavior of the heavy metals Cd, Pb, Cu and Zn was studied experimentally at a 35 MW circulating fluidized bed boiler. The fuel was a Swedish willow (Salix) and quartz sand was used as an additional bed material. Almost no Cd was retained in the bottom ash, whereas Zn was clearly enriched in the bottom ash. 15--27% of Pb was in the gas phase downstream of the cyclone at T = 810 C, but less than 3% of Cd, Cu, or Zn. In the convective pass the gas phase Pb reacted with the coarse fly ash particles. Consequently, all the heavy metals were found entirely in the coarse fly ash particles downstream of the convective pass at T = 150 C. The heavy metals were not enriched in the fine fly ash particles. The coarse fly ash particles were large agglomerates consisting of up to thousands of submicron primary particles. These agglomerates were very effective in capturing volatile heavy metals into the coarse fly ash fraction hindering their condensation and subsequent enrichment in the fine particles.

  18. A dynamic simulation model for power plants with atmospheric and pressurized circulating fluidized bed combustion -- Interactions of plant components and design studies

    SciTech Connect

    Glasmacher-Remberg, C.; Fett, F.N.

    1999-07-01

    Power plants with atmospheric or pressurized circulating fluidized bed combustion are complex technical systems. The operation characteristics of these power plants depend on the behavior of the single components and their interactions. The theoretical understanding of power plant processes of this kind as well as the design, the reliability and the practical operation can be enhanced by the application of mathematical models for the complete process. A dynamic simulation model for power plants with atmospheric circulating fluidized bed combustion (ACFBC) and pressurized circulating fluidized bed combustion (PCFBC) consisting of comprehensive submodels for the subsystems gas turbine, circulating fluidized bed combustor and water/steam cycle is presented. Apart from the investigation of the complete power plant, the simulation program enables the analysis of the three mentioned subsystems separately. Each subsystem is described by a set of unsteady-state differential and algebraic equations solved by an implicit Euler-method using a modified Newton-Raphson method. With the aid of the dynamic simulation program for a selected power plant, the effect of changes in plant operation will be examined for full and part load as well as the transient response of the system due to the carried out operation. Emphasis is laid on the characterization of the interactions between the subsystems. The dynamic simulation program can be used for design studies and it is investigated how changes of the plant design influence the operation characteristics of the example plant.

  19. Pulsed atmospheric fluidized bed combustion. Technical progress report, April--June 1995

    SciTech Connect

    1995-07-31

    Design activities for this report period included: (1) Mechanical. Stress analysis calculations were performed on the steam/water pressure piping. Pipe support design and drawings were completed by Duke Fluor Daniel. The fluid bed distributor bubble cap design was revisited and changes made for ease of maintenance. (2) Electrical and Instrumentation. Control and instrumentation scheme proposed earlier, was based on independent single loop controllers. After careful review, it is decided to go for state of art distributed control system (DCS) which uses programmable logic controllers (PLC). In addition, coal/limestone pickup hopper fabrication was completed during this period and shipped to the site. The coal/limestone floating caps have been made at MTCI and ready for shipping. All major equipment installation was completed. The pulse combustor steam/water jacket and air plenum were installed. Construction of control room building was just completed.

  20. Disposal of Fluidized Bed Combustion Ash in an Underground Mine to Control Acid Mine Drainage and Subsidence

    SciTech Connect

    1998-08-31

    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 feasibility of the approach (i.e. YO void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). During Phase Ill the majority of the activity involves completing two full scale demonstration projects. The eleven acre Longridge mine in Preston County will be filled with 53,000 cubic yards of grout during the spring of 1998 and monitored for following year. The second demonstration involves stowing 2000 tons of ash into an abandoned mine to demonstrate the newly redesigned Burnett Ejector. This demonstration is anticipated to take place during the winter of 1997. This document will report on progress made during Phase Ill. The report will be divided into four major sections. The first will be the Hydraulic Injection component. This section of the report will report on progress and milestones associated with the grouting activities of the project. The Phase Ill tasks of Economic Analysis and Regulatory Analysis will be covered under this section. The second component is Pneumatic Injection. This section reports on progress made towards completing the demonstration project. The Water Quality component involves background monitoring of water quality and precipitation at the Phase Ill (Longridge) mine site. The last component involves evaluating the migration of contaminants through the grouted mine. A computer model has been developed in earlier phases and will model the flow of water in and around the grouted Longridge mine.

  1. CO2 Rebinding by Oil Shale CFBC Ashes: Effect of Pre-Treatment

    NASA Astrophysics Data System (ADS)

    Trikkel, Andres; Keelmann, Merli; Aranson, Aljona; Kuusik, Rein

    Power production in Estonia is predominantly based on combustion of a local low-grade fossil fuel Estonian oil shale. Due to the high content of carbonaceous mineral matter in oil shale, its combustion is related to formation of lime-containing ashes (content of free CaO 10-30%) which could be utilized as sorbents for CO2. In the present research CO2 uptake by circulating fluidized bed and pulverized firing ashes from different technological devices (furnace, cyclones etc) of an operating power plant was studied and the effect of pre-treatment (grinding, calcination at different temperatures) of these ashes on their capture capacity was estimated using thermogravimetric, SEM, X-Ray and EDX analysis methods. It was found that capture capacities were determined mainly by free CaO content in the ashes, thereby, fluidized bed ashes showed higher CaO conversion levels (19.2-74.2%) as compared to pulverized firing ones (8.7-51.8%). Pre-treatment conditions influenced noticeably CO2 uptake. Grinding decreased CO2 capture capacity of fluidized bed ashes, calcination at higher temperatures decreased capture capacity of both types of ashes. Clarification of this phenomenon was given. Kinetic analysis of the process has been carried out, mechanism of the reactions and respective kinetic constants have been estimated.

  2. Modeling of fluidized-bed combustion of coal: Phase II, final reports. Volume 1. Model evolution and development

    SciTech Connect

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

    1980-10-01

    The Energy Laboratory of the Massachusetts Institute of Technology (M.I.T.), under Department of Energy (DOE) sponsorship, has been engaged in the development of a comprehensive mechanistic model of Fluidized Bed Combustors (FBC). The primary aims of this modeling effort are the generation and to the extent possible, validation of an analytical framework for the design and scale-up of fluidized bed combustors. In parallel with this modeling effort, M.I.T. also embarked upon the development of an FBC-Data Base Management System (FBC-DBMS) aimed at facilitating the coordination, interpretation and utilization of the experimental data that are or will become available from diverse sources, as well as in the identification of areas of large uncertainty or having a paucity of experimental results. The synergistic operation of the FBC-Model and FBC-Data Base promises to offer a powerful tool for the design and optimization of FBC's and represents the ultimate goal of the M.I.T. effort. The modeling effort was initially focused upon evaluation and application of state-of-the-art models. The initial system model was divided into five basic components: fluid dynamics, combustion, sulfur capture, heat transfer and emissions. Due to the technical complexity of modeling FBC operation and the initial primitive nature of models for these components, it was deemed necessary to be able to incorporate evolutionary improvements in understanding and correlating FBC phenomena: the M.I.T. system model is, therefore, modular in nature, i.e., each sub-model can be replaced by an updated or equivalent sub-model without necessitating reprogramming of the entire system model.

  3. 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

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

    1980-09-01

    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.

  4. Impact of the addition of chicken litter on mercury speciation and emissions from coal combustion in a laboratory-scale fluidized bed combustor

    SciTech Connect

    Songgeng Li; Shuang Deng; Andy Wu; Wei-ping Pan

    2008-07-15

    Co-combustion of chicken litter with coal was performed in a laboratory-scale fluidized bed combustor to investigate the effect of chicken litter addition on the partitioning behavior of mercury. Gaseous total and elemental mercury concentrations in the flue gas were measured online, and ash was analyzed for particle-bound mercury along with other elemental and surface properties. The mercury mass balance was between 85 and 105%. The experimental results show that co-combustion of chicken litter decreases the amount of elemental and total mercury in the gas phase. Mercury content in fly ash increases with an increasing chicken litter share. 22 refs., 6 figs., 5 tabs.

  5. MARKET ASSESSMENT AND TECHNICAL FEASIBILITY STUDY OF PRESSURIZED FLUIDIZED BED COMBUSTION ASH USE

    SciTech Connect

    A.E. Bland; T.H. Brown

    1997-04-01

    Western Research Institute, in conjunction with the Electric Power Research Institute, Foster Wheeler International, Inc. and the US Department of Energy, has undertaken a research and demonstration program designed to examine the market potential and the technical feasibility of ash use options for PFBC ashes. Ashes from the Foster Wheeler Energia Oy pilot-scale circulating PFBC tests in Karhula, Finland, combusting (1) low-sulfur subbituminous and (2) high-sulfur bituminous coal, and ash from the AEP's high-sulfur bituminous coal-fired bubbling PFBC in Brilliant, Ohio, were evaluated in laboratory and pilot-scale ash use testing at WR1. The technical feasibility study examined the use of PFBC ash in construction-related applications, including its use as a cementing material in concrete and use in cement manufacturing, fill and embankment materials, soil stabilization agent, and use in synthetic aggregate production. Testing was also conducted to determine the technical feasibility of PFBC ash as a soil amendment for acidic and sodic problem soils and spoils encountered in agricultural and reclamation applications. The results of the technical feasibility testing indicated the following conclusions. PFBC ash does not meet the chemical requirements as a pozzolan for cement replacement. However, it does appear that potential may exist for its use in cement production as a pozzolan and/or as a set retardant. PFBC ash shows relatively high strength development, low expansion, and low permeability properties that make its use in fills and embankments promising. Testing has also indicated that PFBC ash, when mixed with low amounts of lime, develops high strengths, suitable for soil stabilization applications and synthetic aggregate production. Synthetic aggregate produced from PFBC ash is capable of meeting ASTM/AASHTO specifications for many construction applications. The residual calcium carbonate and calcium sulfate in the PFE3C ash has been shown to be of value in

  6. Symposium (International) on Combustion, 18th, 1980

    SciTech Connect

    Anon

    1980-08-01

    This conference proceedings contains 196 papers. 181 papers are indexed separately. Topics covered include: combustion generated pollution; propellant combustion; fluidized bed combustion; combustion of droplets and spray; premixed flame studies; fire studies; flame stabilization; coal flammability; chemical kinetics; turbulent combustion; soot; coal combustion; modeling of combustion processes; combustion diagnostics; detonations and explosions; ignition; internal combustion engines; combustion studies; and furnaces.

  7. Investigation of heat transfer and combustion in the advanced fluidized bed combustor (FBC)

    SciTech Connect

    Lee, S.W.

    1999-09-01

    This technical report summarizes the research conducted and progress achieved during the period from April 1, 1998 to June 30, 1998. The numerical simulation was continued to determine the concentration distribution of the gas species, heat flux and heat transfer coefficients in the hot combustor model. The different gas concentration profiles showed the gas mixing characteristics along the combustor height. The center zone of the combustor has a relatively high methane mass concentration. The injection of secondary air squeezes the uprising flue gas and methane that causes the fuel-lean zone near the secondary air nozzles. The carbon dioxide concentration increased with the increasing of the combustor height. The peak concentration of oxygen remains at the combustor wall because of the secondary injection. The heat flux on the wall of the upper chamber is much higher than that of the lower chamber. It is believed that the heat flux is affected by the designed strong swirl and secondary air injection. The heat transfer coefficient changes along the combustor height were also affected by the multiple secondary air injection. The numerical simulation results could verify the predictions of the experimental results. It is a quite similar trend of the heat transfer coefficient changes based on the combustion test results.

  8. Electrodialytic treatment for metal removal from sewage sludge ash from fluidized bed combustion.

    PubMed

    Pazos, M; Kirkelund, G M; Ottosen, L M

    2010-04-15

    Sewage sludge contains several potentially hazardous compounds such as heavy metals, PCBs, PAHs, etc. However, elements with high agricultural value (P, K or Ca) are also present. During the last years, the fluidized bed sludge combustor (FBSC) is considered an effective and novel alternative to treat sewage sludge. By its use, the high amount of sludge is reduced to a small quantity of ash and thermal destruction of toxic organic constituents is obtained. Conversely, heavy metals are retained in the ash. In this work the possibility for electrodialytic metal removal for sewage sludge ash from FBSC was studied. A detailed characterization of the sewage sludge ash was done initially, determining that, with the exception of Cd, the other heavy metals (Cr, Cu, Pb, Ni and Zn) were under the limiting levels of Danish legislation for the use of sewage sludge as fertilizer. After 14 days of electrodialytic treatment, the Cd concentration was reduced to values below the limiting concentration. In all experiments the concentrations of other metals were under limiting values of the Danish legislation. It can be concluded that the electrodialytic treatment is an adequate alternative to reduce the Cd concentration in FBSC ash prior to use as fertilizer. PMID:20034740

  9. Engineering systems analysis of pressurized fluidized-bed-combustion power systems

    SciTech Connect

    Graves, R.L.; Griffin, F.P.; Lackey, M.E.

    1982-04-01

    This effort was conducted to provde supporting data for the research and development program on pressurized fluidized bed combustor (PFBC) systems being continued under the auspices of the Office of Coal Utilization of DOE. This report deals with the first phase of the effort, designated Task 1, which was scoped to be a somewhat broad review of PFBC technology and an analysis to determine its potential and sensitivity to key development needs. Background information pertaining to the application of PFBC to the market for coal-fired technology is included. The status of development is reviewed and the deficiencies in data are identified. Responses to a survey of PFBC developers are reviewed with emphasis on the high risk areas of the PFBC concept. Some of these problems are: uncertainty of life of gas turbine components; lack of demonstration of load following; and hot solids handling. Some high risk areas, such as the gas cleanup or gas turbine systems, can be relieved by reducing the severity of design conditions such as the turbine inlet temperature. Alternate turbine designs or plant configurations are also possible solutions. Analyses were performed to determine whether the advantages held by PFBC systems in cost, efficiency, and emissions would be nullified by measures taken to reduce risk. In general, the results showed that the attractive features of the PFBC could be preserved.

  10. Developing technologies for high volume land application uses of pressurized fluidized-bed combustion (PFBC) ash

    SciTech Connect

    Beeghly, J.H.; Dick, W.A.; Wolfe, W.E.

    1995-12-31

    Dry alkaline flue gas desulfurization (FGD) by-products, including Tidd PFBC bed and cyclone ash are being evaluated for beneficial uses via land application for agriculture, mine spoil reclamation, soil stabilization, and road embankment construction in a 5 year, $4.4 million research program based in Ohio. The beneficial use for agriculture and mine reclamation as a soil amendment material is primarily due to its high acid neutralizing capacity and gypsum content. Concentrations of leachate RCRA heavy metals approached primary drinking water quality standards and are well within the criteria for classification as non-toxic fly ash according to Ohio EPA policy. Characterization tests of compressive strength, permeability, and compressibility indicate the by-products are practical materials for use in high volume engineered fills or embankments, base courses, and for soil reinforcement. Large field demonstrations of technical, economic, and environmental feasibility have been completed using Tidd PFBC ash: (1) to reclaim abandoned coal mineland spoil, (2) as an agricultural lime substitute, (3) in stabilized base construction for a cattle feedlot, and (4) for reconstruction of two state highway embankments. An important factor to understand the behavior of this Tidd PFBC residue is that dolomite was the sorbent.

  11. The role of thermally induced fractures in the calcination and sulfation behavior of sorbents in fluidized bed combustion

    SciTech Connect

    Liu, Y.; Morrison, J.L.; Scaroni, A.W.

    1995-12-31

    In atmospheric pressure, circulating fluidized bed combustors, sorbents are used to minimize SO{sub 2} emissions. It is generally accepted that CaO, formed by decomposition of CaCO{sub 3}, reacts with SO{sub 2} and O{sub 2}: CaCO{sub 3} {yields} CaO + CO{sub 2} and CaO + SO{sub 2} + 1/2 O{sub 2} {yields} CaSO{sub 4} rather than direct sulfation of CaCO{sub 3}: CaCO{sub 3} + SO{sub 2} + 1/2 O{sub 2} {yields} CaSO{sub 4} + CO{sub 2}. Therefore, the physical structure of a calcine, e.g. pore size distribution, accessible surface area, plays an important role in subsequent sulfation behavior. While the use of sorbents to capture SO{sub 2} from combustion gases has been in practice for decades, experimental evaluation is still necessary for selecting a sorbent for a specific application. Naturally occurring sorbents, composed of individual grains of carbonate crystallites, vary greatly in their chemical composition and physical structure. The variation in sorbent properties is often reflected in calcination and sulfation behavior. The present work involved studying the effect of particle size and grain size on the sulfation behavior of six sorbents. The samples covered a wide range of chemical compositions (limestone to dolostone), physical strengths (low to high) and grain structures (fine to coarse-grained).

  12. Development of methane and nitrous oxide emission factors for the biomass fired circulating fluidized bed combustion power plant.

    PubMed

    Cho, Chang-Sang; Sa, Jae-Hwan; Lim, Ki-Kyo; Youk, Tae-Mi; Kim, Seung-Jin; Lee, Seul-Ki; Jeon, Eui-Chan

    2012-01-01

    This study makes use of this distinction to analyze the exhaust gas concentration and fuel of the circulating fluidized bed (CFB) boiler that mainly uses wood biomass, and to develop the emission factors of Methane (CH(4)), Nitrous oxide (N(2)O). The fuels used as energy sources in the subject working sites are Wood Chip Fuel (WCF), RDF and Refused Plastic Fuel (RPF) of which heating values are 11.9 TJ/Gg, 17.1 TJ/Gg, and 31.2 TJ/Gg, respectively. The average concentrations of CH(4) and N(2)O were measured to be 2.78 ppm and 7.68 ppm, respectively. The analyzed values and data collected from the field survey were used to calculate the emission factor of CH(4) and N(2)O exhausted from the CFB boiler. As a result, the emission factors of CH(4) and N(2)O are 1.4 kg/TJ (0.9-1.9 kg/TJ) and 4.0 kg/TJ (2.9-5.3 kg/TJ) within a 95% confidence interval. Biomass combined with the combustion technology for the CFB boiler proved to be more effective in reducing the N(2)O emission, compared to the emission factor of the CFB boiler using fossil fuel. PMID:23365540

  13. Development of Methane and Nitrous Oxide Emission Factors for the Biomass Fired Circulating Fluidized Bed Combustion Power Plant

    PubMed Central

    Cho, Chang-Sang; Sa, Jae-Hwan; Lim, Ki-Kyo; Youk, Tae-Mi; Kim, Seung-Jin; Lee, Seul-Ki; Jeon, Eui-Chan

    2012-01-01

    This study makes use of this distinction to analyze the exhaust gas concentration and fuel of the circulating fluidized bed (CFB) boiler that mainly uses wood biomass, and to develop the emission factors of Methane (CH4), Nitrous oxide (N2O). The fuels used as energy sources in the subject working sites are Wood Chip Fuel (WCF), RDF and Refused Plastic Fuel (RPF) of which heating values are 11.9 TJ/Gg, 17.1 TJ/Gg, and 31.2 TJ/Gg, respectively. The average concentrations of CH4 and N2O were measured to be 2.78 ppm and 7.68 ppm, respectively. The analyzed values and data collected from the field survey were used to calculate the emission factor of CH4 and N2O exhausted from the CFB boiler. As a result, the emission factors of CH4 and N2O are 1.4 kg/TJ (0.9–1.9 kg/TJ) and 4.0 kg/TJ (2.9–5.3 kg/TJ) within a 95% confidence interval. Biomass combined with the combustion technology for the CFB boiler proved to be more effective in reducing the N2O emission, compared to the emission factor of the CFB boiler using fossil fuel. PMID:23365540

  14. Evaluating R and D options under uncertainty. Volume 2. Atmospheric fluidized-bed combustion commercialization strategies. Final report

    SciTech Connect

    Borison, A.B.; Judd, B.R.; Morris, P.A.; Walters, E.C.

    1981-08-01

    This study developed and demonstrated a quantitative framework for analyzing commercialization decisions for emerging electrical power generation technologies. The framework addresses the general question of when to freeze a design for commercialization. The framework was developed to help evaluate the benefits of continuing the development of two different designs for atmospheric fluidized-bed combustion (AFBC) boilers. EPRI staff participated actively in specifying the scope of the analysis and in providing technical information on the two designs. The framework was demonstrated using this information, supplemented with probabilistic judgments by EPRI staff about possible outcomes from the pilot and demonstration stages of development. Based on the technical data and judgments supplied by EPRI staff, the analysis shows a net benefit for proceeding with the development of two designs. Extensive sensitivity analysis shows this result holds over a broad range of input data. The insight behind this result is the value of using a second design as a hedge against an unfavorable outcome with the first design. The degree to which other power generation technologies could serve as a hedge for a single AFBC design was not considered explicitly in the analysis.

  15. The importance of heterogeneous decomposition reactions for the emission levels of NO and N{sub 2}O during fluidized bed combustion of coal

    SciTech Connect

    Boavida, D.; Lobo, L.S.; Gulyurtlu, I.; Cabrita, I.

    1996-12-31

    In the present work, the effects of temperature and type of char on the heterogeneous reduction of both NO and N{sub 2}O on char surfaces were investigated using the TGA technique. The kinetic parameters for the decomposition of both NO and N{sub 2}O on the char surfaces was obtained and correlated with the previous results from the combustion of coals and of the same chars in a laboratorial fluidized bed combustor.

  16. Combustion

    NASA Technical Reports Server (NTRS)

    Bulzan, Dan

    2007-01-01

    An overview of the emissions related research being conducted as part of the Fundamental Aeronautics Subsonics Fixed Wing Project is presented. The overview includes project metrics, milestones, and descriptions of major research areas. The overview also includes information on some of the emissions research being conducted under NASA Research Announcements. Objective: Development of comprehensive detailed and reduced kinetic mechanisms of jet fuels for chemically-reacting flow modeling. Scientific Challenges: 1) Developing experimental facilities capable of handling higher hydrocarbons and providing benchmark combustion data. 2) Determining and understanding ignition and combustion characteristics, such as laminar flame speeds, extinction stretch rates, and autoignition delays, of jet fuels and hydrocarbons relevant to jet surrogates. 3) Developing comprehensive kinetic models for jet fuels.

  17. Characterization of ashes from co-combustion of refuse-derived fuel with coal, wood and bark in a fluidized bed

    SciTech Connect

    Zevenhoven, R.; Skrifvars, B.J.; Hupa, M.

    1998-12-31

    The technical and environmental feasibility of co-combustion of a recovered fuel (RF) prepared from combustible waste fractions (separated at the source), together with coal, peat, wood or wood-waste in thermal power/electricity generation has been studied in several R and D projects within Finland. The current work focuses on eventual changes in ash characteristics during co-combustion of RF with coal, wood or bark, which could lead to bed agglomeration, slagging, fouling and even corrosion in the boiler. Ashes were produced in a 15 kW bubbling fluidized bed (BFB) combustion reactor, the fly ash captured by the cyclone was further analyzed by XRF. The sintering tendency behavior of these ashes was investigated using a test procedure developed at Aabo Akademi University. Earlier, a screening program involved ashes from RF (from a waste separation scheme in Finland) co-combustion with peat, wood and bark, in which ash pellets were thermally treated in air. This showed significant sintering below 600 C as well as above 800 C for RF/wood and RF/bark, but not for RF/peat. This seemed to correlate with alkali chloride and sulfate concentrations in the ashes. The current work addresses a Danish refuse-derived fuel (RDF), co-combusted with bark, coal, bark+coal, wood, and wood+coal (eight tests). Ash pellets were thermally treated in nitrogen in order to avoid residual carbon combustion. The results obtained show no sintering tendencies below 600 C, significant changes in sintering are seen with pellets treated at 1,000 C. Ash from 100% RDF combustion does not sinter, 25% RDF co-combustion with wood and peat, respectively, gives an insignificant effect. The most severe sintering occurs during co-combustion of RDF with bark. Furthermore, it appears that the presence of a 25% coal fraction (on energy basis) seems to have a negative effect on all fuel blends. Analysis of the sintering results versus ash chemical composition shows that, in general, an increased level of

  18. Stearic acid coating on circulating fluidized bed combustion fly ashes and its effect on the mechanical performance of polymer composites

    NASA Astrophysics Data System (ADS)

    Yao, Nina; Zhang, Ping; Song, Lixian; Kang, Ming; Lu, Zhongyuan; Zheng, Rong

    2013-08-01

    The aim of this work was to test circulating fluidized bed combustion fly ashes (CFAs) for its potential to be utilized in polymer composites manufacturing to improve its toughness. CFAs was coated by stearic acid and used in the composite of polypropylene/ethylene vinyl acetate/high density polyethylene (PP/EVA/HDPE) by molding process method. The resulting coated and uncoated CFAs were fully characterized by particle size analyzer, contact angles, powder X-ray diffraction (XRD), thermogravimetric analysis/differential thermal analysis (TGA/DTA), Brunauer-Emmett-Teller (BET), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The stearic acid coated onto the surface of CFAs particles in the physical and chemical ways, and the total clad ratio reached 2.05% by measuring TGA/DTA curve. The percentage of CFAs particles focused to a narrow range 2-4 μm and the median mean size was 3.2 μm more than uncoated CFAs. The properties of hydrophobic and dispersive of CFAs particles improved and original activity was reserved after stearic acid coating. The stearic acid was verified as a coupling agent by how much effect it had on the mechanical properties. It showed the elongation at break of PP/EVA/HDPE reinforced with 15 wt% coated CFAs (c-CFAs) was 80.20% and higher than that of the uncoated. The stearic acid treatment of CFAs is a very promising approach to improve the mechanical strength due to the incorporation of stearic acid on the CFAs surface, and hence, further enhances the potential for recycling CFAs as a suitable filler material in polymer composites.

  19. Erosivity of particles in circulating fluidized bed combustors

    SciTech Connect

    Levy, A.V.; Wang, B.Q.; Geng, G.Q. ); Mack, W. )

    1989-01-01

    The metal wastage of superheater tubes in the convection pass region of circulating fluidized bed combustors (CFBC) is a current problem. An investigation was carried out to determine what kinds of metal loss rates and mechanisms occurred when the various types of particles in CFBC's were used as the erodent in a laboratory blast nozzle tester. The laboratory tests were compared to in-service exposures. A loss mechanism was established that was based on metal losses and the observed microstructures of E-C surfaces. It was additionally determined that more angular and larger size particles have a greater level of erosivity and that the particles must be strong enough not to shatter upon impact in order to be erosive. Favorable comparisons between laboratory and in-service loss mechanisms are reported.

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

    SciTech Connect

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

    1992-09-01

    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 advanced Multi Solids Fluidized Bed (MSFB) boiler designs. The first level of this contract targeted the small package boiler (10,000--50,000 lb/hr steam) and industrial size boiler (75,000--150,000 lb/hr steam) markets. Two representative sizes, 30,000 lb/hr and 110,000 lb/hr of steam, were selected for the two categories for a detailed technical and economic evaluation. Technically, both the designs showed promise, however, the advanced industrial design was favored on economic considerations. It was thus selected for further study in the second level of the contract. Results of this Level-2 effort, presented in this report, consisted of testing the design concept in Riley`s 4.4 MBtu/hr pilot MSFB facility located at Riley Research Center in Worcester, Mass. The design and economics of the proof of concept facility developed in Level-1 of the contract were then revised in accordance with the findings of the pilot test program. A host site for commercial demonstration in Level-3 of the contract was also secured. It was determined that co-firing coal in combination with paper de-inking sludge will broaden the applicability of the design beyond conventional markets. International Paper (IP), the largest paper company in the world, is willing to participate in this part of the program. IP has offered its Hammermill operation at Lockhaven, Pa, site of a future paper de-inking plant, for the proof of concept installation. This plant will go in operation in 1994. It is recommended that METC proceed to the commercial demonstration of the design developed. The approach necessary to satisfy the needs of the customer while meeting the objectives of this program is presented along with a recommended plan of action.

  1. APFBC repowering could help meet Kyoto Protocol CO{sub 2} reduction goals[Advanced Pressurized Fluidized Bed Combustion

    SciTech Connect

    Weinstein, R.E.; Tonnemacher, G.C.

    1999-07-01

    The Clinton Administration signed the 1997 Kyoto Protocol agreement that would limit US greenhouse gas emissions, of which carbon dioxide (CO{sub 2}) is the most significant. While the Kyoto Protocol has not yet been submitted to the Senate for ratification, in the past, there have been few proposed environmental actions that had continued and wide-spread attention of the press and environmental activists that did not eventually lead to regulation. Since the Kyoto Protocol might lead to future regulation, its implications need investigation by the power industry. Limiting CO{sub 2} emissions affects the ability of the US to generate reliable, low cost electricity, and has tremendous potential impact on electric generating companies with a significant investment in coal-fired generation, and on their customers. This paper explores the implications of reducing coal plant CO{sub 2} by various amounts. The amount of reduction for the US that is proposed in the Kyoto Protocol is huge. The Kyoto Protocol would commit the US to reduce its CO{sub 2} emissions to 7% below 1990 levels. Since 1990, there has been significant growth in US population and the US economy driving carbon emissions 34% higher by year 2010. That means CO{sub 2} would have to be reduced by 30.9%, which is extremely difficult to accomplish. The paper tells why. There are, however, coal-based technologies that should be available in time to make significant reductions in coal-plant CO{sub 2} emissions. Th paper focuses on one plant repowering method that can reduce CO{sub 2} per kWh by 25%, advanced circulating pressurized fluidized bed combustion combined cycle (APFBC) technology, based on results from a recent APFBC repowering concept evaluation of the Carolina Power and Light Company's (CP and L) L.V. Sutton steam station. The replacement of the existing 50-year base of power generating units needed to meet proposed Kyoto Protocol CO{sub 2} reduction commitments would be a massive undertaking. It is

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

    PubMed

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

    2013-01-01

    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

  3. Analysis/control of in-bed tube erosion phenomena in the Fluidized Bed Combustion (FBC) System. Technical progress report No. 5

    SciTech Connect

    Lee, S.W.

    1994-01-01

    This technical report summarizes the research work performed and progress achieved during the period of October 1, 1993 to December 31, 1993. Measurement of particle-tube collision frequency was conducted by an electrostatic impact probe in the bench-scale FBC model. Two series of tests were conducted, in one test the probe traversed vertically along the bed axis. The other test conducted that the probe traversed from the center position to the quarter point of bed diagonal and the wall region. The specific weight loss at different tube circumferential was examined to understand the effect of superficial fluidizing velocity. The bottom section of the test tube was found to be more serious erosion than that of the top section. In order to study the effect of tube orientations on in-bed tube erosion, the sample tubes along with four different angles were used. The sample tubes were also placed horizontally and vertically at the center, and vertically near the wall to quantify the effect of the tube location.

  4. A Contribution to the Problem of Initiation of a Combustion Source in an Oil-Saturated Bed

    NASA Astrophysics Data System (ADS)

    Koznacheev, I. A.; Dobrego, K. V.

    2013-11-01

    The problem on in-situ self-ignition of an oil-saturated bed under the conditions of forced filtration of an oxygen-containing gas has been solved with analytical and numerical methods with account of the burnout of a deficient gas component. The influence of the burnout of this component and of convective removal of heat from the bed on the time of its self-ignition has been determined. Recommendations for the optimum regime of initiation of the self-ignition of the bed with account of variation of the blast flow rate and the oxygen content have been given.

  5. Quantitative evaluation of minerals in fly ashes of biomass, coal and biomass-coal mixture derived from circulating fluidised bed combustion technology.

    PubMed

    Koukouzas, Nikolaos; Ward, Colin R; Papanikolaou, Dimitra; Li, Zhongsheng; Ketikidis, Chrisovalantis

    2009-09-30

    The chemical and mineralogical composition of fly ash samples collected from laboratory scale circulating fluidised bed (CFB) combustion facility have been investigated. Three fly ashes were collected from the second cyclone in a 50 kW laboratory scale boiler, after the combustion of different solid fuels. Characterisation of the fly ash samples was conducted by means of X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Quantitative analysis of the crystalline (mineral) and amorphous phases in each ash sample was carried out using the Rietveld-based Siroquant system, with an added spike of ZnO to evaluate the amorphous content. SiO(2) is the dominant oxide in the fly ashes, with CaO, Al(2)O(3) and Fe(2)O(3) also present in significant proportions. XRD results show that all three fly ashes contain quartz, anhydrite, hematite, illite and amorphous phases. The minerals calcite, feldspar, lime and periclase are present in ashes derived from Polish coal and/or woodchips. Ash from FBC combustion of a Greek lignite contains abundant illite, whereas illite is present only in minor proportions in the other ash samples. PMID:19410365

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

    SciTech Connect

    DeLallo, M.; Zaharchuk, R.

    1994-01-01

    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.

  7. Three-zonal engineering method of heat calculation for fluidized bed furnaces based on data on commercial investigations of heat generation distribution during biomass combustion

    NASA Astrophysics Data System (ADS)

    Litun, D. S.; Ryabov, G. A.

    2016-02-01

    A three-zonal method of heat calculation of furnaces for combustion of biomass and low-caloric fuel in the fluidized bed is described. The method is based on equations of thermal and material balances that account for heat generation by fuel in the zone, heat-and-mass transfer heat exchange between the furnace media and surfaces that bound the zone, and heat-and-mass transfer between furnace zones. The calculation procedure for heat generation by fuel in the fluidized bed (FB) using the heat generation portion by the fuel is proposed. Based on commercial investigations, the main factors that affect the average temperature in the FB and the portion of fuel heat that is released in the FB are determined. Results of commercial investigations showed that the airflow coefficient in the FB should be recognized as the main operation parameter that affects the average temperature in the FB and, consequently, heat generation in the FB. The gas flow rate in the FB can be marked out as the second factor that affects the consumption degree of oxidizer supplied in the FB. Commercial investigations revealed that mixing is affected by the gas flow rate in the FB and the bed material particle size, which may be changed during the boiler operation because of the agglomeration of particles of sand and ash. The calculation processing of commercial investigations on a KM-75-40M boiler of a CHP-3 of an Arkhangelsk Pulp and Paper Mill (APPM), which was carried out using the inverse problem procedure by means of a developed computer program, determined the range of the fuel heat release share in the FB, which was 0.26-0.45 at an excess air factor of 0.59-0.93 in the bed, and the heat release share in the maximum temperature zone in the total heat release in the superbed space. The heat release share in the bed is determined as an approximating function of the excess air factor in the bed and the fluidization number. The research results can be used during designing boilers with the

  8. Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion (FBC) system. Technical progress report No. 4, [July 1, 1993--September 30, 1993

    SciTech Connect

    Lee, Seong W.

    1993-11-01

    This technical report Summarizes the research work performed and progress achieved during the period of July 1, 1993 to September 30, 1993. Design and fabrication of the electrostatic impact probe were continued for measuring particle-tube collision frequency in the bench-scale FBC model. To verify the working principle of the electrostatic impact probe and to establish the reliability of probe readings, several readings were performed. The number of impact particles can be conveniently read from the frequency counter by the impact probe, which was reproducible and consistent data. The erosion measurement was conducted under different superficial fluidizing velocity in the bench-scale FBC model. Results of specific weight loss versus excess air velocity (air velocity above the minimum fluidization velocity) show the dominant effect of the fluidizing velocity on the tube erosion. The project has been progressing well. Measurement of the particle-tube collision frequency will be conducted under different tube location by the electrostatic impact probe. Instrumentation for the measurement of the in-bed tube erosion will be continued under various operating conditions. In addition to that, the relationship between the results of particle-tube collision frequency and the measurement of in-bed tube erosion will be predicted.

  9. Second-generation pressurized fluidized-bed combustion plant: Conceptual design and optimization of a second-generation PFB combustion plant. Phase 2, Annual report, October 1991--September 1992

    SciTech Connect

    Robertson, A.; Domeracki, W.; Newby, R.; Rehmat, A.; Horazak, D.

    1992-10-01

    After many years of experimental testing and development work, coal-fired pressurized fluidized bed (PFB) combustion combined-cycle power plants are moving toward reality. Under the US Department of Energy`s Clean Coal Technology Program, a 70-MWe PFB combustion retrofit, utilizing a 1525{degrees}F gas turbine inlet temperature, has been built and operated as a demonstration plant at the American Electric Power Company`s Tidd Plant in Brilliant, Ohio. As PFB combustion technology moves closer and closer to commercialization, interest is turning toward the development of an even more efficient and more cost-effective PFB combustion plant. The targeted goals of this ``second-generation`` plant are a 45-percent efficiency and a cost of electricity (COE) that is at least 20 percent lower than the COE of a conventional pulverized-coal (PC)-fired plant with stack gas scrubbing. In addition, plant emissions should be within New Source Performance Standards (NSPS) and the plant should have high availability, be able to burn different ranks of coal, and incorporate modular construction technologies. In response to this need, a team of companies led by Foster Wheeler Development Corporation (FWDC). The key components in the proposed second-generation plant are the carbonizer, CPFBC, ceramic cross-flow filter, and topping combustor. Unfortunately, none of these components has been operated at proposed plant operating conditions, and experimental tests must be conducted to explore/determine their performance throughout the proposed plant operating envelope. The major thrust of Phase 2 is to design, construct, test, and evaluate the performance of the key components of the proposed plant.

  10. Continuing development of regenerable sorbents for fluidized-bed combustion. Semiannual technical progress report No. 2, April 1-September 30, 1980

    SciTech Connect

    Kalfadelis, C D

    1980-01-01

    Our efforts were directed primarily to preparation for and/the initial operation of the laboratory-scale hot fluidized bed test system (LSHFB). The initial test sequence in the LSHFB system was performed with a fixed-bed of 100 grams of barium titanate synthetic sorbent. The sorbent bed was alternately sulfated and regenerated five times. Sulfation was accomplished at 900/sup 0/C, with a synthetic flue gas mixture comprising 10.1% CO/sub 2/, 4.95% O/sub 2/, 0.2435% SO/sub 2/ and 84.7% N/sub 2/. Regeneration was performed at 1025/sup 0/C with a gas containing 8.0% CO and 92.0% N/sub 2/. After an initial drop in sulfation performance after the first sulfation/regeneration cycle, performance held steady, or was shown to be improving, during the succeeding four cycles. Although the initial operation of this system proceeded relatively smoothly, the reactor was found to have been irreparably damaged by the end of the initial test sequence. A new reactor was subsequently designed, fabricated, and installed in the unit. Concurrently, sorbent pellet preparation by extrusion was investigated in the Catalyst Preparation Facility at the Baton Rouge Laboratory of Exxon Research and Engineering Company. Preparation of sorbent pellets for use in the LSHFB operation was continued on a laboratory-scale at Linden throughout the reporting period. Cost and time estimates were prepared for operation of the bench-scale fluidized bed coal combustion and regeneration facilities, including preparation of the requisite volumes of synthetic sorbent pellets needed for that program.

  11. Northern States Power Company (NSP) Black Dog generating plant - Unit 2 emission reduction, capacity increase and life extension through atmospheric fluidized bed combustion (AFBC) retrofit

    SciTech Connect

    Jenness, B.L.; Rosendahl, S.M.; Gamble, R.L.

    1985-08-01

    The authors report on progress to date of the atmospheric fluidized-bed combustion (AFBC) boiler retrofit at the Black Dog Unit 2 plant of the Northern States Power Company. Construction began in September 1984 after the completion of technical and economic feasibility studies, and initial operation is scheduled for the second quarter of 1986. The project features the largest AFBC boiler to date, a 40 MW capacity regain/upgrade, and 25-year extension of unit life, low leakage regenerative air preheater design, electrostatic precipitator performance improvement, alternate fuel co-firing capacity, and reduced emission on a per MW basis. The authors describe the management and engineering developments associated with the project. 12 figures, 4 tables.

  12. Identification of data gaps found during the development of a zero-order model for a fluidized-bed retort/combustion process

    SciTech Connect

    Ammer, J.R.

    1986-01-01

    This technical note (TN) reports on the development of a zero-order ASPEN (Advanced System for Process Engineering) model for the fluidized-bed retort/combustion of an eastern oil shale. The objective of the work described was to identify data needs and to create a structure for future, more definitive models. New Albany shale was the initial reference eastern shale at the Department of Energy (DOE)/Morgantown Energy Technology Center (METC). A literature search on this shale was conducted to find the physical property data required for the ASPEN model. This TN discusses the types of missing or incomplete data, the process being modeled, and how process variables are affected by varying input parameters. The TN also presents recommendations for increasing the reliability of the simulation. 12 refs., 3 figs., 5 tabs.

  13. Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion (FBC) system. Technical progress report No. 12

    SciTech Connect

    Lee, S.W.

    1995-10-01

    This technical report summarizes the research work performed and progress achieved during the period of July 1, 1995 to October 30, 1995. The characteristics of resistant coatings were determined and related to metal wastage of in-bed tubes in FBC under various laboratory test conditions, The tests were conducted at high impact velocity, 30 m/s, and short exposure time (4 hours) to minimize oxidation of surrounding surface specimens. No oxidation layer founded on the worn surfaces of AISI 1018 carbon steel, The eroded surfaces and cross sections of coatings tested at high velocity were investigated, The surfaces of coating specimens were eroded through a combined mechanism of brittle and ductile modes, These mechanical properties of materials are strongly dependent on the composition and microstate of materials, rather than to their hardness, For high velocity testing, all of the coatings exhibited {open_quotes}brittle behavior{close_quotes}, i.e., the erosion rate at shallow angles was higher than at steep angles and maximum erosion rate at impact angle of 90{degrees}. Tests will be continued and compared with erosion test results for different thermal sprayed coatings.

  14. Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion (FBC) system. Technical progress report No. 3, [April 1, 1993--June 30, 1993

    SciTech Connect

    Lee, Seong W.

    1993-07-01

    This technical report summarizes the research work performed and progress achieved during the period of during the period of April 1, 1993 to June 30, 1993. The erosion test was conducted in the bench-scale FBC model along with the preparation of the test particles/tube specimens. The effect of the tube-to-distributor (T-to-D) clearance was discussed on the tube specific weight loss for low, medium, and high superficial velocities. Electrostatic impact probes for measuring the particle-surface collision frequency were designed to verify the some of the measurement and to identify the primary erosion points. The erosion models were briefly to understand the phenomena of in-bed erosion. The project has been progressing well. Instrumentation for the erosion-measuring will be continued: to measure the tube weight loss under different operating conditions. Development of the electrostatic probes will be continued and implemented for measuring the particle-tube collision frequency in the bench-scale FBC model.

  15. Disposal of fluidized bed combustion ash in an underground mine to control acid mine drainage and subsidence. Quarterly report, March 1--May 31, 1998

    SciTech Connect

    1998-09-01

    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 feasibility of the approach, cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). Phase 1 of the project was completed in September 1995 and was concerned with the development of the grout and a series of predictive models. These models were verified through the Phase 2 field phase and will be further verified in the large scale field demonstration of Phase 3. The verification will allow the results to be packaged in such a way that the technology can be easily adapted to different site conditions. Phase 2 was successfully completed with 1,000 cubic yards of grout being injected into Anker Energy`s Fairfax mine. The grout flowed over 600 feet from a single injection borehole. The grout achieved a compressive strength of over 1,000 psi (twice the level that is needed to guarantee subsidence control). Phase 3 is to take 26 months and will be a full scale test at Anker`s eleven acre Longridge mine site.

  16. Characterisation of polycyclic aromatic hydrocarbons in flue gas and residues of a full scale fluidized bed combustor combusting non-hazardous industrial waste.

    PubMed

    Van Caneghem, J; Vandecasteele, C

    2014-11-01

    This paper studies the fate of PAHs in full scale incinerators by analysing the concentration of the 16 EPA-PAHs in both the input waste and all the outputs of a full scale Fluidized Bed Combustor (FBC). Of the analysed waste inputs i.e. Waste Water Treatment (WWT) sludge, Refuse Derived Fuel (RDF) and Automotive Shredder Residue (ASR), RDF and ASR were the main PAH sources, with phenanthrene, fluoranthene and pyrene being the most important PAHs. In the flue gas sampled at the stack, naphthalene was the only predominant PAH, indicating that the PAHs in FBC's combustion gas were newly formed and did not remain from the input waste. Of the other outputs, the boiler and fly ash contained no detectable levels of PAHs, whereas the flue gas cleaning residue contained only low concentrations of naphthalene, probably adsorbed from the flue gas. The PAH fingerprint of the bottom ash corresponded rather well to the PAH fingerprint of the RDF and ASR, indicating that the PAHs in this output, in contrast to the other outputs, were mainly remainders from the PAHs in the waste inputs. A PAH mass balance showed that the total PAH input/output ratio of the FBC ranged from about 100 to about 2600 depending on the waste input composition and the obtained combustion conditions. In all cases, the FBC was clearly a net PAH sink. PMID:25002370

  17. Investigation of heat transfer and combustion in the advanced fluidized bed combustor (FBC). Technical progress report No. 1, [October 1, 1993--December 31, 1993

    SciTech Connect

    Lee, S.W.

    1994-01-01

    This technical report summarizes the research work performed and progress achieved during the period of October 1, 1993 to December 31, 1993. The newly-concept of exploratory fluidized bed based on the integrating the advantages of fluidized bed combustion (FBC) and cyclonic combustor was designed to study the gas and particle flows and to develop control techniques for gas-particle flow in the FBC. The test chamber was made of transparent acrylic tube with 6in. I.D. to facilitate visual observation. Eight nozzles (s) were made at the freeboard in different levels to provide secondary air, which will generate strong swirling flow field. The progress of this project has been on schedule. Design and fabrication of the exploratory cold test model will be continued with an arrangement of the auxiliary system. After completion of the design/fabrication of the system, the system test will be conducted for the overall system. Instrumentations for the gas/particle flow will be arranged with the auxiliary system. The electrostatic impact probe and associated signal processing units will be designed and fabricated for measuring particle mass flux.

  18. Finial Scientific/Technical Report: Application of a Circulating Fluidized Bed Process for the Chemical Looping Combustion of Solid Fuel

    SciTech Connect

    Dr. Wei-Ping Pan; Dr. John T. Riley

    2005-10-10

    Chemical Looping Combustion is a novel combustion technology for the inherent separation of the greenhouse gas, CO{sub 2}. In 1983, Richter and Knoche proposed reversible combustion, which utilized both the oxidation and reduction of metal. Metal associated with its oxidized form as an oxygen carrier was circulated between two reactors--oxidizer and reducer. In the reducer, the solid oxygen carrier reacts with the fuel to produce CO{sub 2}, H{sub 2}O and elemental metal only. Pure CO{sub 2} will be obtained in the exit gas stream from the reducer after H{sub 2}O is condensed. The pure CO{sub 2} is ready for subsequent sequestration. In the oxidizer, the elemental metal reacts with air to form metal oxide and separate oxygen from nitrogen. Only nitrogen and some unused oxygen are emitted from the oxidizer. The advantage of CLC compared to normal combustion is that CO{sub 2} is not diluted with nitrogen but obtained in a relatively pure form without any energy needed for separation. In addition to the energy-free purification of CO{sub 2}, the CLC process also provides two other benefits. First, NO{sub x} formation can be largely eliminated. Secondly, the thermal efficiency of a CLC system is very high. Presently, the CLC process has only been used with natural gas. An oxygen carrier based on an energy balance analysis and thermodynamics analysis was selected. Copper (Cu) seems to be the best choice for the CLC system for solid fuels. From this project, the mechanisms of CuO reduction by solid fuels may be as follows: (1) If pyrolysis products of solid fuels are available, reduction of CuO could start at about 400 C or less. (2) If pyrolysis products of solid fuels are unavailable and the reduction temperature is lower, reduction of CuO could occur at an onset temperature of about 500 C, char gasification reactivity in CO{sub 2} was lower at lower temperatures. (3) If pyrolysis products of solid fuels are unavailable and the reduction temperature is higher than 750 C

  19. The behaviour of ashes and heavy metals during the co-combustion of sewage sludges in a fluidised bed

    SciTech Connect

    Helena Lopes, M.; Abelha, P.; Lapa, N.; Oliveira, J.S.; Cabrita, I.; Gulyurtlu, I

    2003-07-01

    Co-combustion tests of dry sewage sludges with coal were performed in a pilot bubbling FBC aiming at the characterization of ashes and determining the behaviour of heavy metals in the process. The tests showed compliance with the regulatory levels as far as heavy metal emissions were concerned. The bottom ashes, which accounted for about 70% of the total ash production, were obtained in a granular form, with diameters ranging from 0.5 to 4 mm. The heavy metals were distributed in ashes obtained from different locations of the installation and their concentrations were found to vary depending on the location of capture. The increase in heavy metals content in bottom ashes was not found to lead to higher leachability and ecotoxicity compared to sewage sludges, suggesting that there could be opportunities for their further use. Mercury suffered vaporisation inside the reactor, thus leaving bottom ashes free of contamination by it. However, there was observed a strong retention of mercury in cyclone ashes due to the presence of unburned carbon which probably acted as an adsorbent. The effluent mercury was also found to be mostly associated with the particulate fraction, being less than 20% emitted in gaseous forms. The results suggested that the combustion of the sewage sludge could successfully be carried out and the amount of unburned carbon leaving the combustor but captured in cyclone was large enough to ensure substantial retention of mercury at low temperatures, hence could contribute to an improvement of the mercury release which still remains an issue of great concern to resolve during combustion of waste materials.

  20. The combustion of large particles of char in bubbling fluidized beds: The dependence of Sherwood number and the rate of burning on particle diameter

    SciTech Connect

    Dennis, J.S.; Hayhurst, A.N.; Scott, S.A.

    2006-11-15

    burning char particle; the implication of this correlation is that a completely new picture emerges for the combustion of a char particle in a hot fluidized bed. (author)

  1. Sulfur removal in advanced two stage pressurized fluidized bed combustion. Technical report, December 1, 1994--February 28, 1995

    SciTech Connect

    Abbasian, J.

    1996-03-01

    The objective of this study is to obtain data on the rates and the extent of sulfation reactions involving partially sulfided calcium-based sorbents, and oxygen as well as sulfur dioxide, at operating conditions closely simulating those prevailing in the second stage (combustor) of Advanced Two-Stage Pressurized Fluidized-Bed Combustors (PFBC). In these systems the CO{sub 2} partial pressure generally exceeds the equilibrium value for calcium carbonate decomposition. Therefore, calcium sulfate is produced through the reactions between SO{sub 2} and calcium carbonate as well as the reaction between calcium sulfide and oxygen. To achieve this objective, the rates of reaction involving SO{sub 2} and oxygen (gaseous reactant); and calcium sulfide and calcium carbonate (solid reactants), will be determined by conducting tests in a pressurized thermogravimetric analyzer (HPTGA) unit. The effects of sorbent type, sorbent particle size, reactor temperature and pressure; and O{sub 2} as well as SO{sub 2} partial pressures on the sulfation reactions rate will be determined. During this quarter, samples of the selected limestone and dolomite, sulfided in the fluidized-bed reactor during last quarter, were analyzed. The extent of sulfidation in these samples was in the range of 20 to 50%, which represent carbonizer discharge material at different operating conditions. The high pressure thermogravimetric analyzer (BPTGA) unit has been modified and a new pressure control system was installed to eliminate pressure fluctuation during the sulfation tests.

  2. Sulfur removal in advanced two stage pressurized fluidized bed combustion. Technical report, September 1--November 30, 1994

    SciTech Connect

    Abbasian, J.; Hill, A.; Wangerow, J.R.

    1994-12-31

    The objective of this study is to obtain data on the rates and the extent of sulfation reactions involving partially sulfided calcium-based sorbents, and oxygen as well as sulfur dioxide, at operating conditions closely simulating those prevailing in the second stage (combustor) of Advanced Two-Stage Pressurized Fluidized-Bed Combustors (PFBC). In these systems the CO{sub 2} partial pressure generally exceeds the equilibrium value for calcium carbonate decomposition. Therefore, calcium sulfate is produced through the reactions between SO{sub 2} and calcium carbonate as well as the reaction between calcium sulfide and oxygen. To achieve this objective, the rates of reaction involving SO{sub 2} and oxygen (gaseous reactant); and calcium sulfide and calcium carbonate (solid reactants), will be determined by conducting tests in a pressurized thermogravimetric analyzer (HPTGA) unit. The effects of sorbent type, sorbent particle size, reactor temperature and pressure; and O{sub 2} as well as SO{sub 2} partial pressures on the sulfation reactions rate will be determined. During this quarter, samples of the selected limestone and dolomite were sulfided in the fluidized-bed reactor. These tests were conducted in both calcining and non-calcining operating conditions to produce partially-sulfided sorbents containing calcium oxide and calcium carbonate, respectively. These samples which represent the carbonizer discharge material, will be used as the feed material in the sulfation tests to be conducted in the HPTGA unit during the next quarter.

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

    SciTech Connect

    DeLallo, M.R.; Zaharchuk, R.; Reuther, R.B.; Bonk, D.L.

    1996-09-01

    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.

  4. Comparison of ash behavior of different fuels in fluidised bed combustion using advanced fuel analysis and global equilibrium calculations

    SciTech Connect

    Zevenhoven-Onderwater, M.; Blomquist, J.P.; Skrifvars, B.J.; Backman, R.; Hupa, M.

    1999-07-01

    The behavior of different ashes is predicted by means of a combination of an advanced fuel analysis and global equilibrium calculations. In order to cover a broad spectrum of fuels a coal, a peat, a forest residue and Salix (i.e. willow) are studied. The latter was taken with and without soil contamination, i.e. with a high and low content of silica , respectively. It is shown that mineral matter in fossil and biomass fuels can be present in the matrix of the fuel itself or as included minerals. Using an advanced fuel analysis, i.e. a fractionation method, this mineral content can be divided into four fractions. The first fraction mainly contains those metal ions, that can be leached out of the fuel by water and mainly contains alkali sulfates, carbonates and chlorides. The second fraction mainly consists of those ions leached out by ammonium acetate and covers those ions, that are connected to the organic matrix. The third fraction contains the metals leached out by hydrochloric acid and contains earth alkali carbonates and sulfates as well as pyrites. The rest fraction contains those minerals, that are not leached out by any of the above mentioned solvents, such as silicates. A global equilibrium analysis is used to predict the thermal and chemical behavior of the combined first and second fractions and of the combined third and rest fractions under pressurized and/or atmospheric combustion conditions. Results of both the fuel analysis and the global equilibrium analysis are discussed and practical implications for combustion processes are pointed out.

  5. Energy recovery from municipal solid waste and sewage sludge using multi-solid fluidized bed combustion technology

    NASA Astrophysics Data System (ADS)

    1981-07-01

    The concept is to recover energy as high and low pressure steam, simultaneously. High pressure steam would be generated from flue gas using a conventional tubular boiler. Low pressure steam would be generated by direct contact drying of DSS (as 4 percent solids) with hot sand in a fluidized bed that is an integral part of the MS-FBC process. It is proposed that high pressure steam could be used for district heating or electricity generation. The low pressure steam could be used for close proximity building heat. The results of the investigation show that the MS-FBC process concept for the co-utilization of MSW and DSS is technically feasible and that the thermal efficiency of the process is 76 to 82 percent based on experiments conducted in a 70 to 85 lb/h pilot plant and calculations on three conceptual cases.

  6. Disposal of fluidized bed combustion ash in an underground mine to control acid mine drainage and subsidence. Quarterly report, December 1, 1996--February 28, 1997

    SciTech Connect

    1997-12-31

    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 feasibility of the approach (i.e. % void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). During Phase 3 the majority of the activity involves completing two full scale demonstration projects. The eleven acre Longridge mine in Preston County will be filled with 53,000 cubic yards of grout during the summer of 1997 and monitored for the following year. The second demonstration involves stowing 2,000 tons of ash into an abandoned mine to demonstrate the newly redesigned Burnett Ejector. This demonstration is anticipated to take place during Summer 1997, as well. This document will report on progress made during Phase 3. The report will be divided into four major sections. The first will be the Hydraulic Injection component. This section of the report will report on progress and milestones associated with the grouting activities of the project. The Phase 3 tasks of Economic Analysis and Regulatory Analysis will be covered under this section. The second component is Pneumatic Injection. This section reports on progress made towards completing the demonstration project. The Water Quality component involves background monitoring of water quality and precipitation at the Phase 3 (Longridge) mine site. The last component involves evaluating the migration of contaminants through the grouted mine. A computer model has been developed in earlier phases and will model the flow of water in and around the grouted Longridge mine.

  7. Disposal of fluidized bed combustion ash in an underground mine to control acid mine drainage and subsidence. Quarterly report, December 1, 1996--February 28, 1997

    SciTech Connect

    1997-12-31

    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 feasibility of the approach (i.e. % void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). During Phase 3 the majority of the activity involves completing two full scale demonstration projects. The eleven acre Longridge mine in Preston County will be filled with 53,000 cubic yards of grout during the summer of 1997 and monitored for the following year. The second demonstration involves stowing 2,000 tons of ash into an abandoned mine to demonstrate the newly redesigned Burnett Ejector. This demonstration is anticipated to take place during Summer 1997, as well. This document will report on progress made during Phase 3. The report will be divided into four major sections. The first will be the Hydraulic Injection component. This section of the report will report on progress and milestones associated with the grouting activities of the project. The Phase 3 tasks of Economic Analysis and Regulatory Analysis is covered under this section. The second component is Pneumatic Injection. This section reports on progress made towards completing the demonstration project. The Water Quality component involves background monitoring of water quality and precipitation at the Phase 3 (Longridge) mine site. The last component involves evaluating the migration of contaminants through the grouted mine. A computer model has been developed in earlier phases and will model the flow of water in and around the grouted Longridge mine. The Gantt Chart on the following page details progress by task.

  8. Disposal of fluidized bed combustion ash in an underground mine to control acid mine drainage and subsidence. Quarterly report, September 1--November 30, 1997

    SciTech Connect

    1997-12-31

    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 feasibility of the approach (i.e., % void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). During Phase 3 the majority of the activity involves completing two full scale demonstration projects. The eleven acre Longridge mine in Preston County will be filled with 53,000 cubic yards of grout during the spring of 1998 and monitored for following year. The second demonstration involves stowing 2,000 tons of ash into an abandoned mine to demonstrate the newly redesigned Burnett Ejector. This demonstration is anticipated to take place during the winter of 1997. This document will report on progress made during Phase 3. The report will be divided into four major sections. The first will be the Hydraulic Injection component. This section of the report will report on progress and milestones associated with the grouting activities of the project. The Phase 3 tasks of Economic Analysis and Regulatory Analysis will be covered under this section. The second component is Pneumatic Injection. This section reports on progress made towards completing the demonstration project. The Water Quality component involves background monitoring of water quality and precipitation at the Phase 3 (Longridge) mine site. The last component involves evaluating the migration of contaminants through the grouted mine. A computer model has been developed in earlier phases and will model the flow of water in and around the grouted Longridge mine.

  9. Sulfur removal in advanced two stage pressurized fluidized bed combustion. Technical report, March 1--May 31, 1995

    SciTech Connect

    Abbasian, J.

    1995-12-31

    The objective of this study is to obtain data on the rates and the extent of sulfation reactions involving partially sulfided calcium-based sorbents, and oxygen as well as sulfur dioxide, at operating conditions closely simulating those prevailing in the second stage (combustor) of Advanced Two-Stage Pressurized Fluidized-Bed Combustors. In these systems the CO{sub 2} partial pressure generally exceeds the equilibrium value for calcium carbonate decomposition. Therefore, calcium sulfate is produced through the reactions between SO{sub 2} and calcium carbonate as well as the reaction between calcium sulfide and oxygen. To achieve this objective, the rates of reaction involving SO{sub 2} and oxygen, calcium sulfide and calcium carbonate will be determined by conducting tests in a pressurized thermogravimetric analyzer unit. The sulfate tests conducted during this quarter, focused on the determination of the rate of sulfation reaction involving partially sulfided half-calcined dolomite and oxygen. The test parameters included CO{sub 2} and O{sub 2} concentrations, reaction temperature and pressure, as well as the sorbent particle size. The results obtained during this quarter suggest that the rate of sulfation reaction involving partially sulfided half-calcined dolomite and oxygen is very fast at temperatures above 850 C which rapidly increases with increasing temperature, achieving more than 85% conversion in less than a few minutes. The reaction appears to continue to completion, however, above 85% conversion, the rate of reaction appears to be low, requiring long residence time to reach complete conversion.

  10. Alkali activation of recovered fuel-biofuel fly ash from fluidised-bed combustion: Stabilisation/solidification of heavy metals.

    PubMed

    Yliniemi, Juho; Pesonen, Janne; Tiainen, Minna; Illikainen, Mirja

    2015-09-01

    Recovered fuel-biofuel fly ash from a fluidized bed boiler was alkali-activated and granulated with a sodium-silicate solution in order to immobilise the heavy metals it contains. The effect of blast-furnace slag and metakaolin as co-binders were studied. Leaching standard EN 12457-3 was applied to evaluate the immobilisation potential. The results showed that Ba, Pb and Zn were effectively immobilised. However, there was increased leaching after alkali activation for As, Cu, Mo, Sb and V. The co-binders had minimal or even negative effect on the immobilisation. One exception was found for Cr, in which the slag decreased leaching, and one was found for Cu, in which the slag increased leaching. A sequential leaching procedure was utilized to gain a deeper understanding of the immobilisation mechanism. By using a sequential leaching procedure it is possible fractionate elements into watersoluble, acid-soluble, easily-reduced and oxidisable fractions, yielding a total 'bioavailable' amount that is potentially hazardous for the environment. It was found that the total bioavailable amount was lower following alkali activation for all heavy metals, although the water-soluble fraction was higher for some metals. Evidence from leaching tests suggests the immobilisation mechanism was chemical retention, or trapping inside the alkali activation reaction products, rather than physical retention, adsorption or precipitation as hydroxides. PMID:26054963

  11. Developing technologies for high-volume land application uses of pressurized fluidized-bed combustion (PFBC) ash

    SciTech Connect

    Beeghly, J.H.; Dick, W.A.; Wolfe, W.

    1995-04-01

    Dry alkaline flue gas desulfurization (FGD) by-products, including Tidd PFBC bed and cyclone ash are being evaluated for beneficial uses via land application for agriculture, mine spoil reclamation, soil stabilization, and road embankment construction in a 5 year, $4.4 million research program based in Ohio. The beneficial use for agriculture and mine reclamation as a soil amendment material is primarily due to its high acid neutralizing capacity and gypsum content. Concentrations of leachate RCRA heavy metals approached primary drinking water quality standards and are well within the criteria for classification as non-toxic fly ash according to Ohio EPA policy. Characterization tests of compressive strength, permeability, and compressibility indicate the by-products are practical materials for use in high volume engineered fills or embankments, base courses, and for soil reinforcement. Large field demonstrations of technical, economic, and environmental feasibility have been completed using Tidd PFBC ash (1) to reclaim abandoned coal mineland spoil, (2) as an agricultural lime substitute, (3) in stabilized base construction for a cattle feedlot, and (4) for reconstruction of two state highway embankments. An important factor to understand the behavior of this Tidd PFBC residue is that dolomite was the sorbent.

  12. Determination of flue gas alkali concentrations in fluidized-bed coal combustion by excimer-laser-induced fragmentation fluorescence

    SciTech Connect

    Hartinger, K.T.; Monkhouse, P.B.; Wolfrum, J.; Baumann, H.; Bonn, B.

    1994-12-31

    Gas-phase sodium concentrations were measured for the first time in situ in the flue gas of a fluidized-bed reactor by the excimer-laser-induced fragmentation fluorescence (ELIF) technique. This method involves using ArF-excimer laser light at 193 nm to simultaneously photodissociate the alkali compounds of interest and excite electronically the alkali atoms formed. The resulting fluorescence from Na (3{sup 2}P) atoms can he readily detected at 589 nm. Measured signals were converted to absolute concentrations using a calibration system that monitors alkali compounds under known conditions of temperature, pressure, and composition and rising the same optical setup as at the reactor. Several different coals were investigated under a specific set of reactor conditions at total pressures close to 1 bar. Sodium concentrations ranging from the sub-ppb region to 20 ppb were obtained, and a detection limit for sodium of 0.1 ppb under the present conditions was estimated. Over the course of the reactor program, contrasting concentration histories were observed for the two lignites and the hard coal investigated. In particular, significantly higher sodium concentrations were found for the hard coal, consistent with both the higher chlorine and sodium contents determined in the corresponding coal analysis.

  13. DISPOSAL OF FLUIDIZED BED COMBUSTION ASH IN AN UNDERGROUND MINE TO CONTROL ACID MINE DRAINAGE AND SUBSIDENCE

    SciTech Connect

    Unknown

    2000-10-01

    This project evaluated the technical, economic and environmental feasibility of filling abandoned underground mine voids with coal combustion byproducts. Success was measured in terms of technical feasibility of the approach (i.e. % void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). Phase 1 of the project was completed in September 1995 and was concerned with the development of the grout and a series of predictive models. These models were verified through the Phase II field phase and will be further verified fin the large scale field demonstration of Phase III. The verification allows the results to be packaged in such a way that the technology can be easily adapted to different site conditions. Phase II was successfully completed with 1000 cubic yards of grout being injected into Anker Energy's Fairfax mine. The grout flowed over 600 feet from a single injection borehole. The grout achieved a compressive strength of over 1000 psi (twice the level that is needed to guarantee subsidence control). Phase III was a full scale test at Anker's eleven acre Longridge mine site. The CCB grout replaced what was an open mine void with a solid so that the groundwater tends to flow around and through the pillars rather than through the previously mined areas. The project has demonstrated that CCBs can be successfully disposed in underground mines. Additionally, the project has shown that filling an abandoned underground mine with CCBs can lead to the reduction and elimination of environmental problems associated with underground mining such as acid mine drainage and subsidence. The filling of the Longridge Mine with 43,000 cubic yards of CCB grout resulted in a 97% reduction in acid mine drainage coming from the mine.

  14. Fluidized bed combustor modeling

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    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.

  15. Modeling of fluidized-bed combustion of coal: Phase II, final reports. Volume IV. FBC-Model-II manual

    SciTech Connect

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

    1980-10-01

    This document is the fourth of the seven volume series of our Phase II Final Report. The purpose of this manual is to describe how to access and use M.I.T.'s Fluidized Bed Combustor (FBC) System Program. Presently, the FBC program is stored in a Honeywell Computer System and can be accessed using the Multics interactive system. The intention in writing this manual is to answer the questions that may arise regarding the mechanics of operating the system program, as well as warn the user of possible pitfalls and mistakes that could be made. No attempt is made here to describe the internals of the systems program. The manual describes the procedures an individual would follow to become an active user of the system program. It then explains the various options available for reaching the Multics interactive system on Honeywell 6180 computer on which the program runs. For users outside the Metropolitan Boston area, a public network for data communications is described which is relatively inexpensive. As the system program is approached through Multics using a special command facility TPSA, a separate introduction is provided for Multics TPSA. This facility allows commands appropriate for testing the program and carrying out parametric studies to be executed in a convenient way. Multics TPSA was formulated to meet the needs of the FBC project in particular. Finally, some sample sessions are presented which illustrate the login and logout procedures, the command language, and the data manipulation features of the FBC program. The use of commands helpful in debugging the program is also illustrated.

  16. Effect of application of fluidized bed combustion residue to reclaimed mine pastures on forage yield, composition, animal performance, and mineral status

    SciTech Connect

    Smedley, K.O.

    1985-01-01

    Reclaimed surface mined soils in Appalachia are typically infertile and must be amended for optimum vegetative growth. Fluidized bed combustion residue (FBCR) has high levels of Ca, S, Zn, Fe, and Al, and 50% of the neutralizing capacity of limestone. Three treatments were applied to three capacity of limestone. Three treatments were applied to three replicated 0.81 ha reclaimed mine pastures: (A) control (no amendment), (B) 6760 kg FBCR/ha, and (C) 3380 kg limestone/ha. Based on forage availability, six steers were rotationally grazed on pastures receiving each treatment. Steers were weighed and blood samples collected at 14-d intervals and all animals were sacrificed for tissue sampling at the end of the 114-d trial. B and C increased soil pH above control levels. Forage yield and steer gain were not significantly affected by treatment. Forage samples collected during the trial indicated that B and C amendments elevated forage ash, Ca, Mg, S, Cu, and Ca:P ratio and depressed cellulose and NDF. The forage sampled the following spring was lower in hemicellulose, Zn, Mn and Ni; and higher in ash, Ca, S, the Ca:P ratio in the B and C pastures. Mean serum mineral levels of steers were not affected by pasture treatment. The blood packed cell volume was higher in cattle grazing pastures. Liver levels of Fe, Mn, Ni, and Na and bile levels of Mn were depressed in cattle grazing B and C and serum was at deficiency levels and was not detectable in bile, regardless of treatment. Kidney levels of Ca, Mg and P were higher, hair Zn was higher, rib Cr and long bone Cd levels were lower in animals grazing the pastures. This study suggests that FBCR amendment enhances nutrient quality of forage and minerals status of animals at least as well as limestone application to acidic reclaimed mine pastures.

  17. Fluidized bed injection assembly for coal gasification

    DOEpatents

    Cherish, Peter; Salvador, Louis A.

    1981-01-01

    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.

  18. Post Combustion Test Bed Development

    SciTech Connect

    Cabe, James E.; King, Dale A.; Freeman, Charles J.

    2011-12-30

    Pacific Northwest National Laboratory (PNNL) assessment methodology and slip-stream testing platform enables the comprehensive early-stage evaluation of carbon capture solvents and sorbents utilizing a breadth of laboratory experimental capability as well as a testing platform at a nearby 600 MW pulverized coal-fired power plant.

  19. 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.Y. Maistrenko; V.P. Patskov; A.I. Topal; T.V. Patskova

    2007-09-15

    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.

  20. Self-cementitious properties of fly ashes from CFBC boilers co-firing coal and high-sulphur petroleum coke

    SciTech Connect

    Sheng Guanghong; Li Qin; Zhai Jianping . E-mail: jpzhai@nju.edu.cn; Li Feihu

    2007-06-15

    Self-cementitious properties of fly ash from circulating fluidized bed combustion boiler co-firing coal and high-sulphur petroleum coke (CPFA) were investigated. CPFA was self-cementitious which was affected by its fineness and chemical compositions, especially the contents of SO{sub 3} and free lime (f-CaO). Higher contents of SO{sub 3} and f-CaO were beneficial to self-cementitious strength; the self-cementitious strength increases with a decrease of its 45 {mu}m sieve residue. The expansive ratio of CPFA hardened paste was high because of generation of ettringite (AFt), which was influenced by its water to binder ratio (W/A), curing style and grinding of the ash. The paste cured in water had the highest expansive ratio, and grinding of CPFA was beneficial to its volume stability. The hydration products of CPFA detected by X-ray diffraction (XRD) and scanning electron microscopy (SEM) were portlandite, gypsum, AFt and hydrated calcium silicate (C-S-H)

  1. Design and assembly of a catalyst bed gas generator for the catalytic decomposition of high concentration hydrogen peroxide propellants and the catalytic combustion of hydrocarbon/air mixtures

    NASA Technical Reports Server (NTRS)

    Lohner, Kevin A. (Inventor); Mays, Jeffrey A. (Inventor); Sevener, Kathleen M. (Inventor)

    2004-01-01

    A method for designing and assembling a high performance catalyst bed gas generator for use in decomposing propellants, particularly hydrogen peroxide propellants, for use in target, space, and on-orbit propulsion systems and low-emission terrestrial power and gas generation. The gas generator utilizes a sectioned catalyst bed system, and incorporates a robust, high temperature mixed metal oxide catalyst. The gas generator requires no special preheat apparatus or special sequencing to meet start-up requirements, enabling a fast overall response time. The high performance catalyst bed gas generator system has consistently demonstrated high decomposition efficiency, extremely low decomposition roughness, and long operating life on multiple test articles.

  2. Characterization study and five-cycle tests in a fixed-bed reactor of titania-supported nickel oxide as oxygen carriers for the chemical-looping combustion of methane.

    PubMed

    Corbella, Beatriz M; de Diego, Luis F; García-Labiano, Francisco; Adánez, Juan; Palaciost, José M

    2005-08-01

    Recent investigations have shown that in the combustion of carbonaceous compounds CO2 and NOx emissions to the atmosphere can be substantially reduced by using a two stage chemical-looping process. In this process, the reduction stage is undertaken in a first reactor in which the framework oxygen of a reducible inorganic oxide is used, instead of the usual atmospheric oxygen, for the combustion of a carbonaceous compound, for instance, methane. The outlet gas from this reactor is mostly composed of CO2 and steam as reaction products and further separation of these two components can be carried out easily by simple condensation of steam. Then, the oxygen carrier found in a reduced state is transported to a second reactor in which carrier regeneration with air takes place at relatively low temperatures, consequently preventing the formation of thermal NOx. Afterward, the regenerated carrier is carried to the first reactor to reinitiate a new cycle and so on for a number of repetitive cycles, while the carrier is able to withstand the severe chemical and thermal stresses involved in every cycle. In this paper, the performance of titania-supported nickel oxides has been investigated in a fixed-bed reactor as oxygen carriers for chemical-looping combustion of methane. Samples with different nickel oxide contents were prepared by successive incipient wet impregnations, and their performance as oxygen carriers was investigated at 900 degrees C and atmospheric pressure in five-cycle fixed-bed reactor tests using pure methane and pure air for the respective reduction and regeneration stages. The evolution of the outlet gas composition in each stage was followed by gas chromatography, and the involved chemical, structural, and textural changes of the carrier in the reactor bed were studied by using different characterization techniques. From the study, it is deduced that the reactivity of these nickel-based oxygen carriers is in the two involved stages and almost independent

  3. Heat transfer in high temperature fluidized beds with immersed tubes for coal combustion service. Final report, October 1, 1977-March 31, 1981

    SciTech Connect

    Welty, J. R.

    1984-01-01

    The project involved two parts: analytical and experimental. The progression of work includes the following major divisions: analytical studies involving studies of heat transfer, hydrodynamics of gas flow within the bed, and some considerations of bubble and adjacent tube influences on the heat transfer; experimental apparatus including the instrumented tubes for heat transfer measurements, digital data acquisition, and the high temperature fluidized bed test facility; experimental results; and experimental validation of the analytical model.

  4. Effect of biomass-sulfur interaction on ash composition and agglomeration for the co-combustion of high-sulfur lignite coals and olive cake in a circulating fluidized bed combustor.

    PubMed

    Varol, Murat; Atimtay, Aysel T

    2015-12-01

    This study aimed to investigate the effect of biomass-sulfur interaction on ash composition and agglomeration for the co-combustion of high-sulfur lignite coals and olive cake in a circulating fluidized bed combustor. The tests included co-combustion of 50-50% by wt. mixtures of Bursa-Orhaneli lignite+olive cake and Denizli-Kale lignite+olive cake, with and without limestone addition. Ash samples were subjected to XRF, XRD and SEM/EDS analyses. While MgO was high in the bottom ash for Bursa-Orhaneli lignite and olive cake mixture, Al2O3 was high for Denizli-Kale lignite and olive cake mixture. Due to high Al2O3 content, Muscovite was the dominant phase in the bottom ash of Denizli Kale. CaO in the bottom ash has increased for both fuel mixtures due to limestone addition. K was in Arcanite phase in the co-combustion test of Bursa/Orhaneli lignite and olive cake, however, it mostly appeared in Potassium Calcium Sulfate phase with limestone addition. PMID:26407346

  5. Development of the instrumentation and modeling for heat transfer characteristics in CFBC

    SciTech Connect

    Lee, Seong W.

    1996-04-01

    This technical report summarizes the research performed and progress achieved during the period of October 1, 1995 to March 31, 1996. The bench-scale circulating fluidized bed (CFB) system was carefully designed and fabricated to study gas/particle flow and heat transfer characteristics on the wall of the CFB riser. Design and fabrication of the major components such as gas distributor, cyclone, wind box, surge tank, solid control valve, and riser were summarized in this report. The air supply subsystems including blower, control valve, PVC piping, and air flow measuring devices are arranged and described. The advanced data acquisition system and instrumentation will be developed/applied to measure pressure change along the CFB riser height, gas/particle velocities, local heat transfer coefficient on the wall of CFB, and mass flux of the solid particles. The heat transfer probe will be designed to measure the bed-surface heat transfer coefficient on the wall of the CFB riser. In addition, an electrostatic probe will be designed to measure the local mass flux of the solid particles in the CFB. The progress of this project has been on schedule. The arrangement of the auxiliary subsystems for the bench-scale CFB will be completed for the system test. 4 refs., 6 figs.

  6. Fast fluidized bed steam generator

    DOEpatents

    Bryers, Richard W.; Taylor, Thomas E.

    1980-01-01

    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.

  7. Investigation of heat transfer and combustion in the advanced Fluidized Bed Combustor (FBC). Technical progress report No. 13, October 1996--December 1996

    SciTech Connect

    Lee, Seong W.

    1997-01-01

    This technical report summarizes the research conducted and progress achieved during the period from October 1, 1996 to December 31, 1996. Numerical simulation was acquired from the particle trajectories by means of the Reynolds Stress Model (REM) with general algebraic expressions. The typical particle trajectories for bunch particle injection were predicted by the top view, the side view, and the isolated 3-dimensional view. The simulation of particle trajectories showed top view, side view, and isolated 3-dimensional view. Numerical simulation for the bunch particle injection will be continued to understand the particle characteristics in the combustion chamber. The system test was conducted on the exploratory hot model. Thermal performance and combustion products of the test results were analyzed and predicted. The effect of cooling water on the combustion chamber was studied using the natural gas as a one of firing fuel. Without a providing of cooling water, overall combustion temperatures are increased. A computer-assisted data acquisition system was employed to measure the flue gas compositions/stack temperature. The measurement of combustion products was conducted by the gas analyzer.

  8. Fluidized bed boiler feed system

    DOEpatents

    Jones, Brian C.

    1981-01-01

    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.

  9. Development fo the Instrumentation and Modeling for Heat Transfer Characteristice in CFBC

    SciTech Connect

    Seong W. Lee

    1999-09-29

    This technical report summarizes the research conducted and results obtained during the period beginning April 1, 1999 to September 30, 1999. Numerical simulation was used to predict the air velocity and pressure, temperature, and heat transfer characteristics in the CFB system. The radial air velocities changed frequently because of the voidage and gas pressure drop that caused in the heat transfer probe inlet level (k=23). The lower pressure zone was formed near the chamber's center region. The higher pressure zone was formed at the surrounding of the secondary air flow. The lower temperature profiles were shown to be near the CFB riser wall side. In the radial direction, the gas temperature nearest to the center region was higher than that near the wall zone. The heat flux was changed along the radial direction of the CFB riser. The heat transfer probe was designed and installed in the CFB riser. The heat transfer rate at different axial/radial locations of the CFB riser will be measured by the heat transfer probe. A model will be proposed to predict the heat transfer coefficients along the axial and radial variation of the bed in the CFB system.

  10. Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion (FBC) system. [Quarterly] technical progress report No. 11, April 1, 1995--June 30, 195

    SciTech Connect

    Lee, Seong W.

    1995-07-01

    This technical report summarizes the research work performed and progress achieved during the period of April 1, 1995 to June 30, 1995. In this study, the preliminary analysis of test data and understanding of the erosion behavior of resistant coatings for the in-bed tube materials were discussed for one the remedies of preventing in-bed tube erosion. The material wastage of the specimen was determined by weight and thickness loss measurements. The morphologies of the specimens were examined by scanning electron microscopy (SEM). For the material wastage. of the coating specimens, High Velocity Oxygen Fuel (HVOF) coatings (DS200) and the arc-sprayed coating at elevated temperature condition exhibited 2 to 3 times lower erosion wastage than that of AISI 1018 steel. For the angular dependence of erosion rate, two coatings exhibited the ductile behavior as demonstrated by higher wastage rates at shallow impact angle than that at steep impact angle. Tests will be continued and compared with erosion test results from higher velocity test conditions.

  11. Can Chemical Looping Combustion Use CFB Technology?

    SciTech Connect

    Gamwo, I.K.

    2006-11-01

    Circulating Fluidized Bed (CFB) technology has demonstrated an unparalleled ability to achieve low SO2 and NOx emissions for coal-fired power plants without CO2 capture. Chemical Looping combustion (CLC) is a novel fuel combustion technology which appears as a leading candidate in terms of competitiveness for CO2 removal from flue gas. This presentaion deals with the adaptation of circulating fluidized bed technology to Chemical looping combustion

  12. Second generation pressurized fluidized-bed combustion (PFBC) research and development, Phase 2 -- Task 4, carbonizer testing. Volume 1, Test results

    SciTech Connect

    Froehlich, R.; Robertson, A.; Vanhook, J.; Goyal, A.; Rehmat, A.; Newby, R.

    1994-11-01

    During the period beginning November 1991 and ending September 1992, a series of tests were conducted at Foster Wheeler Development Corporation in a fluidized-bed coal carbonizer to determine its performance characteristics. The carbonizer was operated for 533 hours in a jetting fluidized-bed configuration during which 36 set points (steady-state periods) were achieved. Extensive data were collected on the feed and product stream compositions, heating values, temperatures, and flow rates. With these data, elemental and energy balances were computed to evaluate and confirm accuracy of the data. The carbonizer data were not as self-consistent as could be desired (balance closure imperfection). A software package developed by Science Ventures, Inc., of California, called BALAID, was used to reconcile the carbonizer data; the details of the reconciliation have been given in Volume 1 of this report. The reconciled data for the carbonizer were rigorously analyzed, correlations were developed, and the model was updated accordingly. The model was then used in simulating each of the 36 steady-state periods achieved in the pilot plant. The details are given in this Volume of the report.

  13. Second generation pressurized fluidized-bed combustion (PFBC) research and development, Phase 2 --- Task 4, carbonizer testing. Volume 2, Data reconciliation

    SciTech Connect

    Froehlich, R.; Robertson, A.; Vanhook, J.; Goyal, A.; Rehmat, A.; Newby, R.

    1994-11-01

    During the period beginning November 1991 and ending September 1992, a series of tests were conducted at Foster Wheeler Development Corporation in a fluidized-bed coal carbonizer to determine its performance characteristics. The carbonizer was operated for 533 hours in a jetting fluidized-bed configuration during which 36 set points (steady-state periods) were achieved. Extensive data were collected on the feed and product stream compositions, heating values, temperatures, and flow rates. With these data, elemental and energy balances were computed to evaluate and confirm accuracy of the data. The carbonizer data were not as self-consistent as could be desired (balance closure imperfection). A software package developed by Science Ventures, Inc., of California, called BALAID, was used to reconcile the carbonizer data; the details of the reconciliation have been given in Volume 1 of this report. The reconciled data for the carbonizer were rigorously analyzed, correlations were developed, and the model was updated accordingly. The model was then used in simulating each of the 36 steady-state periods achieved in the pilot plant. The details are given in this Volume one. This Volume 2 provides details of the carbonizer data reconciliation.

  14. System design study to reduce capital and operating costs and bench-scale testing of a circulating-bed AFB [atmospheric pressure fluidized bed] advanced concept: Phase 1, Design, cost estimate, and cost comparison for MWK circulating fluid bed combustor and oil-fired boilers: Final report

    SciTech Connect

    Sadhukhan, P.; Lin, Y.Y.; Hsiao, K.H.; Richards, S.R.; Wagner, C.; Settle, W.H.; Bryant, J.; Gorman, W.A.; Newlin, T.; Shires, P.J.; James, J.L.

    1986-06-01

    The Department of Energy (DOE) issued an RFP for a "System Design Study to Reduce Capital and Operating Cost and Bench Scale Testing of a Circulating-Bed AFB Advanced Concept." The design and cost study of a 150,000 pounds per hour steam boiler comprised Phase-I of the RFP. The objective was to produce a design with improved performance and reduced capital and operating costs compared with conventional atmospheric pressure fluidized bed (AFB) boilers. The final result was a significant reduction of capital cost - 36% below the lowest AFB plant cost. The steam cost was 24% below the corresponding cost for the AFB process. In June 1985, DOE issued a Change Order (C001) to the Phase-I study in order for MWK to design and estimate the cost for a scaled-down coal-fired (Illinois No. 6, 3% S) CFBC plant producing low pressure and low temperature steam (75,000lbs/hr, 200 psig, 387{degree}F), and to compare the costs -capital and steam costs -with those for a packaged high sulfur (3%) fuel oil-fired boiler, which is of the same capacity and requires SO{sub 2} removal. An additional objective was to estimate the cost for a No. 2 fuel oil-fired boiler that does not need any SO{sub 2} scrubber. An evaluation of the sensitivity of the steam cost to the oil-fired boiler capital cost and to fuel prices was also to be undertaken. The cost of steam produced by the No. 6 fuel oil boiler is 52% higher than the cost for CFBC, and the corresponding cost for the No. 2 fuel oil plant is 43% higher. Again, a large advantage for the CFBC comes from the low price of coal relative to that of oil. The large cost advantage of steam calculated for the MWK CFBC using coal as a fuel over the oil-fired boilers would remain even in the worst case scenario of a declining oil price accompanied by a steady coal price. 7 refs., 25 figs., 34 tabs.

  15. Comparison of different natural sorbents for removing CO{sub 2} from combustion gases, as studied in a bench-scale fluidized bed

    SciTech Connect

    M. Ives; R.C. Mundy; P.S. Fennell; J.F. Davidson; J.S. Dennis; A.N. Hayhurst

    2008-11-15

    The reaction of CO{sub 2} with porous particles of CaO for chicken eggshells, mussel shells, and limestone. The reaction is a promising way of removing CO{sub 2}, e.g., from the exhaust of a power station, so that a pure stream of CO{sub 2} can subsequently be produced for sequestration by calcining (roasting) the solid CaCO{sub 3}. The reverse of the reaction regenerates the sorbent, which can thus be used cyclically. The reaction were investigated using a small electrically heated bed of sand at about 750{degree}C, fluidized by N{sub 2}. Typically, a sample (about 2 g) of cleaned calcareous material (sieved to about 600 {mu}m) was added to the hot bed, and the CO{sub 2} produced was measured, while the material was fully calcined. Next, enough CO{sub 2} was added to the fluidizing N{sub 2} to raise (CO{sub 2}) to above the value for equilibrium; thus, the CaO was carbonated. This forward step is shown to exhibit an apparent final conversion, the carrying capacity of the sorbent, below unity. This carrying capacity reduces after several cycles of calcination and carbonation, because blockage of pores denies access of CO{sub 2} to part of the CaO. After several such cycles, particles were removed from the reactor, either in their partially carbonated or fully calcined states, for studies using gas adsorption analysis, X-ray diffraction, and mercury porosimetry. Interestingly, it was found for all three sorbents that the carrying capacity of CaO for CO{sub 2} degraded at a similar rate. The carrying capacity was roughly proportional to the volume of pores narrower than about 100 nm, as measured by Barrett-Joyner-Halenda (BJH) gas adsorption analysis. Evidently, these narrow pores contain both the surface area for CO{sub 2} to absorb and the empty volume to accommodate the product, CaCO{sub 3}. The resistance of eggshells to attrition was broadly comparable to that of Purbeck (U.K.) limestone. 24 refs., 8 figs., 2 tabs.

  16. Bed bugs.

    PubMed

    Foulke, Galen T; Anderson, Bryan E

    2014-09-01

    The term bed bug is applied to 2 species of genus Cimex: lectularius describes the common or temperate bed bug, and hemipterus its tropical cousin. Cimex lectularius is aptly named; its genus and species derive from the Latin words for bug and bed, respectively. Though the tiny pest is receiving increased public attention and scrutiny, the bed bug is hardly a new problem. PMID:25577850

  17. Starting procedure for internal combustion vessels

    DOEpatents

    Harris, Harry A.

    1978-09-26

    A vertical vessel, having a low bed of broken material, having included combustible material, is initially ignited by a plurality of ignitors spaced over the surface of the bed, by adding fresh, broken material onto the bed to buildup the bed to its operating depth and then passing a combustible mixture of gas upwardly through the material, at a rate to prevent back-firing of the gas, while air and recycled gas is passed through the bed to thereby heat the material and commence the desired laterally uniform combustion in the bed. The procedure permits precise control of the air and gaseous fuel mixtures and material rates, and permits the use of the process equipment designed for continuous operation of the vessel.

  18. Modeling of fluidized-bed combustion of coal: Phase II, final reports. Volume VII. FBC Data-Base-Management System (FBC-DBMS) users manual

    SciTech Connect

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

    1980-10-01

    The primary goal of the Fluidized Bed Combustor Data Base (FBCDB) is to establish a data repository for the express use of designers and research personnel involved in FBC development. FBCDB is implemented on MIT's 370/168 computer, using the Model 204 Data Base Management System (DBMS) developed by Computer Corporation of America. DBMS is a software that provides an efficient way of storing, retrieving, updating and manipulating data using an English-like query language. The primary content of FBCDB is a collection of data points defined by the value of a number of specific FBC variables. A user may interactively access the data base from a computer terminal at any location, retrieve, examine, and manipulate the data as well as produce tables or graphs of the results. More than 20 program segments are currently available in M204 User Language to simplify the user interface for the FBC design or research personnel. However, there are still many complex and advanced retrieving as well as applications programs to be written for this purpose. Although there are currently 71 entries, and about 2000 groups reposited in the system, this size of data is only an intermediate portion of our selection. The usefulness of the system at the present time is, therefore, limited. This version of FBCDB will be released on a limited scale to obtain review and comments. The document is intended as a reference guide to the use of FBCDB. It has been structured to introduce the user to the basics of FBCDB, summarize what the available segments in FBCDB can do, and give detailed information on the operation of FBCDB. This document represents a preliminary draft of a Users Manual. The draft will be updated when the data base system becomes fully implemented. Any suggestions as to how this manual may be improved will be appreciated.

  19. Modeling of fluidized-bed combustion of coal: Phase II, final reports. Volume VI. FBC-Data Base-Management-System (FBC-DBMS) development

    SciTech Connect

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

    1980-10-01

    The primary goal of the Fluidized Bed Combustor Data Base, (FBCDB), situated in MIT's Energy laboratory, is to establish a data repository for the express use of designers and research personnel involved in FBC development. DBMS is a software that provides an efficient way of storing, retrieving, updating and manipulating data using an English-like query language. It is anticipated that the FBCDB would play an active and a direct role in the development of FBC technology as well as in the FBC commercial application. After some in-house experience and after a careful and extensive review of commercially available database systems, it was determined that the Model 204 DBMS by Computer Corporation of America was the most suitable to our needs. The setup of a prototype in-house database also allowed us to investigate and understand fully the particular problems involved in coordinating FBC development with a DBMS. Various difficult aspects were encountered and solutions had been sought. For instance, we found that it was necessary to rename the variables to avoid repetition as well as to increase usefulness of our database and, hence, we had designed a classification system for which variables were classified under category to achieve standardization of variable names. The primary content of FBCDB is a collection of data points defined by the value of a number of specific FBC variables. A user may interactively access the database from a computer terminal at any location, retrieve, examine, and manipulate the data as well as produce tables or graphs of the results.

  20. Char binder for fluidized beds

    DOEpatents

    Borio, Richard W.; Accortt, Joseph I.

    1981-01-01

    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.

  1. Dual fluidized bed design for the fast pyrolysis of biomass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A mechanism for the transport of solids between fluidised beds in dual fluidised bed systems for the fast pyrolysis of biomass process was selected. This mechanism makes use of an overflow standpipe to transport solids from the fluidised bed used for the combustion reactions to a second fluidised be...

  2. Heat exchanger support apparatus in a fluidized bed

    DOEpatents

    Lawton, Carl W.

    1982-01-01

    A heat exchanger is mounted in the upper portion of a fluidized combusting bed for the control of the temperature of the bed. A support, made up of tubes, is extended from the perforated plate of the fluidized bed up to the heat exchanger. The tubular support framework for the heat exchanger has liquid circulated therethrough to prevent deterioration of the support.

  3. 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...

  4. Dual Fluidized Bed Biomass Gasification

    SciTech Connect

    2005-09-30

    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.

  5. Disposal of fluidized bed combustion ash in an underground mine to control acid mine drainage and subsidence - phase II - small scale field demonstration. Topical report, December 1, 1996--February 28, 1997

    SciTech Connect

    Ziemkiewicz, P.F.; Head, W.J.; Gray, D.D.; Siriwardane, H.J.; Sack, W.A.

    1998-01-01

    It has been proposed that a mix made from fly and bottom ash from atmospheric pressure fluidized bed coal combusters (FBC ash), water, and stabilizers be injected from the surface into abandoned room and pillar coal mines through boreholes. Besides ash disposal, this process would prevent subsidence and acid mine drainage. Such a mix (called `grout`) needs to be an adequately stable and flowable suspension for it to spread and cover large areas in the mine. This is necessary as the drilling of the boreholes will be an expensive operation and the number such holes should be minimized. Addition of bentonite was found to be needed for this purpose. A suitable grout mix was tested rheologically to determine its fluid flow properties. Finding little published information on such materials, tests were performed using a commercial rotational viscometer with a T-bar rotor and a stand which produced a helical rotor path. Existing mixer viscometer test methods were modified and adapted to convert the measurements of torque vs. angular speed to the material properties appearing in several non-Newtonian constitutive equations. Yield stress was measured by an independent test called the vane method. The rheological behavior was a close fit to the Bingham fluid model. Bleed tests were conducted to ascertain the stability of the mixtures. Spread tests were conducted to compare the flowability of various mixes. Using the flow parameters determined in the laboratory, numerical simulations of grout flow were performed and compared with the results of scale model and field tests. A field injection of this grout was performed at the Fairfax mines in Preston county, W.V.. The observations there proved that this FBC ash grout flows as desired, is a very economical way of disposing the environmentally menacing ash, while also preventing the subsidence and acid mine drainage of the mines.

  6. Moving Bed, Granular Bed Filter Development Program: Option 1, Component Test Facility. Task 2, Identification of technical issues

    SciTech Connect

    Haas, J.C.; Wilson, K.B.

    1994-03-01

    Combustion Power, under the auspices of the US Department of Energy, is developing a moving granular-bed filter for the control of particulate in gasification and pressurized fluidized bed environments. In Task 2, technical issues are identified which need to be resolved for the granular-bed filter to be commercially viable. The technical issues are ranked in relative importance.

  7. Fluidized bed charcoal particle production system

    SciTech Connect

    Sowards, N.K.

    1985-04-09

    A fluidized bed charcoal particle production system, including apparatus and method, wherein pieces of combustible waste, such as sawdust, fragments of wood, etc., are continuously disposed within a fluidized bed of a pyrolytic vessel. Preferably, the fluidized bed is caused to reach operating temperatures by use of an external pre-heater. The fluidized bed is situated above an air delivery system at the bottom of the vessel, which supports pyrolysis within the fluidized bed. Charcoal particles are thus formed within the bed from the combustible waste and are lifted from the bed and placed in suspension above the bed by forced air passing upwardly through the bed. The suspended charcoal particles and the gaseous medium in which the particles are suspended are displaced from the vessel into a cyclone mechanism where the charcoal particles are separated. The separated charcoal particles are quenched with water to terminate all further charcoal oxidation. The remaining off-gas is burned and, preferably, the heat therefrom used to generate steam, kiln dry lumber, etc. Preferably, the bed material is continuously recirculated and purified by removing tramp material.

  8. Solids feed nozzle for fluidized bed

    DOEpatents

    Zielinski, Edward A.

    1982-01-01

    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.

  9. Combustion engineering issues for solid fuel systems

    SciTech Connect

    Bruce Miller; David Tillman

    2008-05-15

    The book combines modeling, policy/regulation and fuel properties with cutting edge breakthroughs in solid fuel combustion for electricity generation and industrial applications. This book provides real-life experiences and tips for addressing the various technical, operational and regulatory issues that are associated with the use of fuels. Contents are: Introduction; Coal Characteristics; Characteristics of Alternative Fuels; Characteristics and Behavior of Inorganic Constituents; Fuel Blending for Combustion Management; Fuel Preparation; Conventional Firing Systems; Fluidized-Bed Firing Systems; Post-Combustion Emissions Control; Some Computer Applications for Combustion Engineering with Solid Fuels; Gasification; Policy Considerations for Combustion Engineering.

  10. Propagation of a fluidization - combustion wave

    SciTech Connect

    Pron, G.P.; Gusachenko, L.K.; Zarko, V.E.

    1994-05-01

    A fluidization-combustion wave propagating through a fixed and initially cool bed was created by igniting coal at the top surface of the bed. The proposed physical interpretation of the phenomenon is in qualitative agreement with the experimental dependences of the characteristics of the process on determining parameters. A kindling regime with forced wave propagation is suggested.

  11. Formation and Reduction of Pollutants in CFBC: From Heavy Metals, Particulates, Alkali, NOx, N2O, SOx, HCl

    NASA Astrophysics Data System (ADS)

    Winter, Franz

    Due to the advantages of fluidized bed combustors a wide range of different fuels is utilized. The fuels range from anthracite, medium and low rank coals to peat, wood residues, biomass waste, sewage sludge and other sludges to plastics and municipal solid waste. Because of this wide range of fuels pollutants such as heavy metals, particulates, alkali, NO, NO2, N2O, SO2, SO3 and HCI may be formed during the fuel conversion process depending on the fuel and operating conditions.

  12. Combustion noise

    NASA Technical Reports Server (NTRS)

    Strahle, W. C.

    1977-01-01

    A review of the subject of combustion generated noise is presented. Combustion noise is an important noise source in industrial furnaces and process heaters, turbopropulsion and gas turbine systems, flaring operations, Diesel engines, and rocket engines. The state-of-the-art in combustion noise importance, understanding, prediction and scaling is presented for these systems. The fundamentals and available theories of combustion noise are given. Controversies in the field are discussed and recommendations for future research are made.

  13. Fluidized bed combustor and tube construction therefor

    DOEpatents

    De Feo, Angelo; Hosek, William

    1981-01-01

    A fluidized bed combustor comprises a reactor or a housing which has a windbox distributor plate adjacent the lower end thereof which contains a multiplicity of hole and air discharge nozzles for discharging air and coal into a fluidized bed which is maintained above the distributor plate and below a take-off connection or flue to a cyclone separator in which some of the products of combustion are treated to remove the dust which is returned into the fluidized bed. A windbox is spaced below the fluidized bed and it has a plurality of tubes passing therethrough with the passage of combustion air and fluidizing air which passes through an air space so that fluidizing air is discharged into the reaction chamber fluidized bed at the bottom thereof to maintain the bed in a fluidized condition. A fluid, such as air, is passed through the tubes which extend through the windbox and provide a preheating of the combustion air and into an annular space between telescoped inner and outer tubes which comprise heat exchanger tubes or cooling tubes which extend upwardly through the distributor plate into the fluidized bed. The heat exchanger tubes are advantageously arranged so that they may be exposed in groups within the reactor in a cluster which is arranged within holding rings.

  14. Tube construction for fluidized bed combustor

    DOEpatents

    De Feo, Angelo; Hosek, William

    1984-01-01

    A fluidized bed combustor comprises a reactor or a housing which has a windbox distributor plate adjacent the lower end thereof which contains a multiplicity of hole and air discharge nozzles for discharging air and coal into a fluidized bed which is maintained above the distributor plate and below a take-off connection or flue to a cyclone separator in which some of the products of combustion are treated to remove the dust which is returned into the fluidized bed. A windbox is spaced below the fluidized bed and it has a plurality of tubes passing therethrough with the passage of combustion air and fluidizing air which passes through an air space so that fluidizing air is discharged into the reaction chamber fluidized bed at the bottom thereof to maintain the bed in a fluidized condition. A fluid, such as air, is passed through the tubes which extend through the windbox and provide a preheating of the combustion air and into an annular space between telescoped inner and outer tubes which comprise heat exchanger tubes or cooling tubes which extend upwardly through the distributor plate into the fluidized bed. The heat exchanger tubes are advantageously arranged so that they may be exposed in groups within the reactor in a cluster which is arranged within holding rings.

  15. Fluidized-Bed Waste-Heat Recovery System development. Semiannual report, February 1-July 31, 1982

    SciTech Connect

    Cole, W. E.; DeSaro, R.; Griffith, J.; Joshi, C.

    1982-08-01

    The Fluidized-Bed Waste-Heat Recovery (FBWHR) System is designed to preheat this combustion air using the heat available in dirty flue gas streams. In this system, a recirculating medium is heated by the flue gas in a fluidized bed. The hot medium is then removed from the bed and placed in a second fluidized bed where it is fluidized by the combustion air. Through this process, the combustion air is heated. The cooled medium is then returned to the first bed. Initial development of this concept is for the aluminum smelting industry.

  16. Solid fuel feed system for a fluidized bed

    DOEpatents

    Jones, Brian C.

    1982-01-01

    A fluidized bed for the combustion of coal, with limestone, is replenished with crushed coal from a system discharging the coal laterally from a station below the surface level of the bed. A compartment, or feed box, is mounted at one side of the bed and its interior separated from the bed by a weir plate beneath which the coal flows laterally into the bed while bed material is received into the compartment above the plate to maintain a predetermined minimum level of material in the compartment.

  17. Fluidized bed heat exchanger utilizing angularly extending heat exchange tubes

    DOEpatents

    Talmud, Fred M.; Garcia-Mallol, Juan-Antonio

    1980-01-01

    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 and includes a steam drum disposed adjacent the fluidized bed and a series of tubes connected at one end to the steam drum. A portion of the tubes are connected to a water drum and in the path of the air and the gaseous products of combustion exiting from the bed. Another portion of the tubes pass through the bed and extend at an angle to the upper surface of the bed.

  18. Development of a new method for improving load turndown in fluidized bed combustors: Final report

    SciTech Connect

    Brown, R.C.

    1988-12-01

    The objective of this research was to investigate a new concept in fluidized bed design that improves load turndown capability. This improvement is accomplished by independently controlling heat transfer and combustion in the combustor. The design consists of two fluidized beds, one central and one annular. The central bed serves as the combustion bed. The annular bed is fluidized separately from the combustion bed and its level of fluidization determine the overall heat transfer rate from the combustion bed to the surrounding water jacket. Early theoretical considerations suggested a load turndown exceeding ten was possible for this design. This research consisted of three major phases: development of a computational model to predict heat transfer in the two-bed combustor, heat transfer measurements in hot-and-cold flow models of the combustor, and combustion tests in an optimally designed combustor. The computation model was useful in selecting the design of the combustor. Annular bed width and particle sizes were chosen with the aid of the model. The heat transfer tests were performed to determine if the existing correlations for fluidized bed heat transfer coefficients were sufficiently accurate for high aspect ratio fluidized beds (such as the annular bed in the combustor). Combustion tests were performed in an optimally designed combustor. Three fuel forms were used: double screened, crushed coal, coal-water-limestone mixtures (CWLM), and coal-limestone briquettes. 18 refs., 30 figs., 8 tabs.

  19. Method for in situ combustion

    DOEpatents

    Pasini, III, Joseph; Shuck, Lowell Z.; Overbey, Jr., William K.

    1977-01-01

    This invention relates to an improved in situ combustion method for the recovery of hydrocarbons from subterranean earth formations containing carbonaceous material. The method is practiced by penetrating the subterranean earth formation with a borehole projecting into the coal bed along a horizontal plane and extending along a plane disposed perpendicular to the plane of maximum permeability. The subterranean earth formation is also penetrated with a plurality of spaced-apart vertical boreholes disposed along a plane spaced from and generally parallel to that of the horizontal borehole. Fractures are then induced at each of the vertical boreholes which project from the vertical boreholes along the plane of maximum permeability and intersect the horizontal borehole. The combustion is initiated at the horizontal borehole and the products of combustion and fluids displaced from the earth formation by the combustion are removed from the subterranean earth formation via the vertical boreholes. Each of the vertical boreholes are, in turn, provided with suitable flow controls for regulating the flow of fluid from the combustion zone and the earth formation so as to control the configuration and rate of propagation of the combustion zone. The fractures provide a positive communication with the combustion zone so as to facilitate the removal of the products resulting from the combustion of the carbonaceous material.

  20. Pulsed atmospheric fluidized bed combustor apparatus

    DOEpatents

    Mansour, Momtaz N.

    1993-10-26

    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.

  1. Heat transfer in circulating fluidized bed combustor

    SciTech Connect

    Bucak, O.; Dogan, O.M.; Uysal, B.Z.

    1999-07-01

    The importance of fluidized bed combustion in utilizing the energy of especially low quality coals is widely accepted. Among various fluidized bed combustion technologies, circulating fluidized beds are preferred as a result of the efforts to get higher combustion efficiencies. The aim of the present research was to investigate the applicability of this technology to Turkish lignites. To achieve this object a 6.5 m tall pilot circulating fluidized bed combustor with 155 mm diameter and all the auxiliary equipment were designed, constructed and tested using Seyitomer lignite of 0.9--2.38 mm in size. Heat transfer from the bed to the water cooling jackets was examined to recover the combustion energy. The inside heat transfer coefficient was determined to be around 121 W/m{sup 2} K for the suspension density of 20--55 kg/m{sup 3}. The agreement of the experimental findings with theoretical estimations was also checked. Furthermore, the thermal efficiency of the system for the heat recovered was found to be 63%.

  2. Fluid-bed air-supply system

    DOEpatents

    Zielinski, Edward A.; Comparato, Joseph R.

    1979-01-01

    The air-supply system for a fluidized-bed furnace includes two air conduits for the same combustion zone. The conduits feed separate sets of holes in a distributor plate through which fluidizing air flows to reach the bed. During normal operation, only one conduit and set of holes is used, but the second conduit and set of holes is employed during start-up.

  3. Converting a fuel to combustible gas

    SciTech Connect

    Moss, G.

    1985-04-02

    A sulfur-containing fuel is passed into a first fluidized bed containing CaSO/sub 4/ and CaO and an oxygen-transfer mediator (e.g. H/sub 2/) whereby the fuel is converted to combustible gas, some CaSO/sub 4/ being reduced to CaS and sulfur being fixed as CaS by reaction with CaO. Bed particles pass from the bottom layer of the first bed into the bottom layer of the second bed which is fluidized by air at conditions such that some, but not all of the CaS is selectively oxidized to CaSO/sub 4/ with no liberation of sulfur moieties. Bed particles pass from the bottom layer of second bed to the bottom layer of a third bed optionally after passage via a fourth bed between the second and third beds. In the third bed particles are fluidized with air to convert CaS selectively to CaSO/sub 4/ with no liberation of sulfur moiety whereby to raise the particles' temperature sufficiently above that of the first bed that particles passing from the bottom layer of the third bed into the bottom layer of the first bed provide sufficient sensible heat to maintain the fuel conversion temperature of the first bed. In the fourth bed particles are fluidized with air under such conditions that sulfur moiety is liberated, preferably at a rate which approximately equals the rate of sulfur-capture in the first bed whereby to maintain approximately a constant amount of reactive CaO in the beds for sulfur-capture in the first bed.

  4. Computational Combustion

    SciTech Connect

    Westbrook, C K; Mizobuchi, Y; Poinsot, T J; Smith, P J; Warnatz, J

    2004-08-26

    Progress in the field of computational combustion over the past 50 years is reviewed. Particular attention is given to those classes of models that are common to most system modeling efforts, including fluid dynamics, chemical kinetics, liquid sprays, and turbulent flame models. The developments in combustion modeling are placed into the time-dependent context of the accompanying exponential growth in computer capabilities and Moore's Law. Superimposed on this steady growth, the occasional sudden advances in modeling capabilities are identified and their impacts are discussed. Integration of submodels into system models for spark ignition, diesel and homogeneous charge, compression ignition engines, surface and catalytic combustion, pulse combustion, and detonations are described. Finally, the current state of combustion modeling is illustrated by descriptions of a very large jet lifted 3D turbulent hydrogen flame with direct numerical simulation and 3D large eddy simulations of practical gas burner combustion devices.

  5. Simulating Combustion

    NASA Astrophysics Data System (ADS)

    Merker, G.; Schwarz, C.; Stiesch, G.; Otto, F.

    The content spans from simple thermodynamics of the combustion engine to complex models for the description of the air/fuel mixture, ignition, combustion and pollutant formation considering the engine periphery of petrol and diesel engines. Thus the emphasis of the book is on the simulation models and how they are applicable for the development of modern combustion engines. Computers can be used as the engineers testbench following the rules and recommendations described here.

  6. Method for increasing the calorific value of gas produced by the in situ combustion of coal

    DOEpatents

    Shuck, Lowell Z.

    1978-01-01

    The present invention relates to the production of relatively high Btu gas by the in situ combustion of subterranean coal. The coal bed is penetrated with a horizontally-extending borehole and combustion is initiated in the coal bed contiguous to the borehole. The absolute pressure within the resulting combustion zone is then regulated at a desired value near the pore pressure within the coal bed so that selected quantities of water naturally present in the coal will flow into the combustion zone to effect a hydrogen and carbon monoxide-producing steam-carbon reaction with the hot carbon in the combustion zone for increasing the calorific value of the product gas.

  7. Bed Bugs FAQs

    MedlinePlus

    ... Tropical Diseases Laboratory Diagnostic Assistance [DPDx] Parasites Home Bed Bugs FAQs Recommend on Facebook Tweet Share Compartir On ... are bed bugs treated and prevented? What are bed bugs? Bed bugs ( Cimex lectularius ) are small, flat, parasitic ...

  8. Method for in situ gasification of a subterranean coal bed

    DOEpatents

    Shuck, Lowell Z.

    1977-05-31

    The method of the present invention relates to providing controlled directional bores in subterranean earth formations, especially coal beds for facilitating in situ gasification operations. Boreholes penetrating the coal beds are interconnected by laser-drilled bores disposed in various arrays at selected angles to the major permeability direction in the coal bed. These laser-drilled bores are enlarged by fracturing prior to the gasification of the coal bed to facilitate the establishing of combustion zones of selected configurations in the coal bed for maximizing the efficiency of the gasification operation.

  9. NO formation during agricultural straw combustion.

    PubMed

    Ren, Qiangqiang; Zhao, Changsui; Duan, Lunbo; Chen, Xiaoping

    2011-07-01

    NO formation during combustion of four typical kinds of straw (wheat straw, rice straw, cotton stalk and corn stalk) which belong to soft straw and hard straw was studied in a tubular quartz fixed bed reactor under conditions relevant to grate boiler combustion. Regarding the real situation in biomass fired power plants in China, NO formation from blended straw combustion was also investigated. Nitrogen transfer during blended straw pyrolysis was performed using a thermogravimetric analyzer (TGA) coupled with a Fourier transform infrared (FTIR) spectrometer. The results show that NO conversion for the four straws during combustion is distinctive. Over 70% fuel-N converts into NO for cotton stalk, while only 37% for wheat straw under the same condition. When wheat straw and cotton stalk were mixed, N-NO conversion increases. The limestone addition promotes NO emission during cotton stalk combustion. The presence of SO(2) in atmosphere suppresses NO formation from straw combustion. PMID:21592786

  10. Fluidized-Bed Waste-Heat Recovery System development. Semiannual report, 1 August 1982-31 January 1983

    SciTech Connect

    Cole, W.E.; DeSaro, R.; Joshi, C.

    1983-02-01

    The Fluidized-Bed Waste-Heat Recovery (FBWHR) System is designed to preheat this combustion air using the heat available in dirty flue gas streams. In this system, a recirculating medium is heated by the flue gas in a fluidized bed. The hot medium is then removed from the bed and placed in a second fluidized bed where it is fluidized by the combustion air. Through this process, the combustion air is heated. The cooled medium is then returned to the first bed. Initial development of this concept is for the aluminum smelting industry.

  11. Fluidized-Bed Waste-Heat Recovery System development. Semiannual report, 1 August 1981-31 January 1982

    SciTech Connect

    Cole, W. E.; DeSaro, R.; Joshi, C.

    1982-02-01

    The Fluidized-Bed Waste-Heat Recovery (FBWHR) System is designed to preheat this combustion air using the heat available in dirty flue gas streams. In this system, a recirculating medium is heated by the flue gas in a fluidized bed. The hot medium is then removed from the bed and placed in a second fluidized bed where it is fluidized by the combustion air. Through this process, the combustion air is heated. The cooled medium is then returned to the first bed. Initial development of this concept is for the aluminum smelting industry.

  12. A staged fluidized-bed comubstion and filter system

    SciTech Connect

    Mei, J.S.; Halow, J.S.

    1993-12-31

    A staged fluidized-bed combustion and filter system for substantially reducing the quantity of waste through the complete combustion into ash-type solids and gaseous products. The device has two fluidized- bed portions, the first primarily as a combustor/pyrolyzer bed, and the second as a combustor/filter bed. The two portions each have internal baffles to define stages so that material moving therein as fluidized beds travel in an extended route through those stages. Fluidization and movement is achieved by the introduction of gasses into each stage through a directional nozzle. Gases produced in the combustor/pyrolyzer bed are permitted to travel into corresponding stages of the combustor/filter bed through screen filters that permit gas flow but inhibit solids flow. Any catalyst used in the combustor/filter bed is recycled. The two beds share a common wall to minimize total volume of the system. A slightly modified embodiment can be used for hot gas desulfurization and sorbent regeneration. Either side-by-side rectangular beds or concentric beds can be used. The system is particularly suited to the processing of radioactive and chemically hazardous waste.

  13. Ignition and combustion features of biofuels

    NASA Astrophysics Data System (ADS)

    Ryzhkov, A. F.; Silin, V. E.; Bogatova, T. F.; Nadir, S. M.

    2011-07-01

    This paper presents the results of experimental investigations of the ignition and combustion of plant biofuels (wood particles, date stones) and products of their mechanical and thermal treatment (pellets, charcoal) at temperatures typical of the burning process in nonforced furnaces and fixed-bed and fluidized-bed gas producers. The influence of the furnace heat treatment of a fuel on its inflammation and combustion has been revealed. The results have been compared with the known data on the burning of pellets, brown coals, and anthracites and with the calculation by the classical diffusion-kinetic model.

  14. Combustion detector

    NASA Technical Reports Server (NTRS)

    Trimpi, R. L.; Nealy, J. E.; Grose, W. L. (Inventor)

    1973-01-01

    A device has been developed for generating a rapid response signal upon the radiation-emitting combustion reaction of certain gases in order to provide a means for the detection and identification of such reaction and concurrently discriminate against spurious signals. This combustion might be the first stage of a coal mine explosion process, and thereby this device could provide a warning of the impending explosion in time to initiate quenching action. This device has the capability of distinguishing between the light emitted from a combustion reaction and the light emitted by miners' lamps, electric lamps, welding sparks or other spurious events so that the quenching mechanism is triggered only when an explosion-initiating combustion occurs.

  15. Combustion physics

    NASA Astrophysics Data System (ADS)

    Jones, A. R.

    1985-11-01

    Over 90% of our energy comes from combustion. By the year 2000 the figure will still be 80%, even allowing for nuclear and alternative energy sources. There are many familiar examples of combustion use, both domestic and industrial. These range from the Bunsen burner to large flares, from small combustion chambers, such as those in car engines, to industrial furnaces for steel manufacture or the generation of megawatts of electricity. There are also fires and explosions. The bountiful energy release from combustion, however, brings its problems, prominent among which are diminishing fuel resources and pollution. Combustion science is directed towards finding ways of improving efficiency and reducing pollution. One may ask, since combustion is a chemical reaction, why physics is involved: the answer is in three parts. First, chemicals cannot react unless they come together. In most flames the fuel and air are initially separate. The chemical reaction in the gas phase is very fast compared with the rate of mixing. Thus, once the fuel and air are mixed the reaction can be considered to occur instantaneously and fluid mechanics limits the rate of burning. Secondly, thermodynamics and heat transfer determine the thermal properties of the combustion products. Heat transfer also plays a role by preheating the reactants and is essential to extracting useful work. Fluid mechanics is relevant if work is to be performed directly, as in a turbine. Finally, physical methods, including electric probes, acoustics, optics, spectroscopy and pyrometry, are used to examine flames. The article is concerned mainly with how physics is used to improve the efficiency of combustion.

  16. Advanced expander test bed program

    NASA Technical Reports Server (NTRS)

    Masters, A. I.; Mitchell, J. C.

    1991-01-01

    The Advanced Expander Test Bed (AETB) is a key element in NASA's Chemical Transfer Propulsion Program for development and demonstration of expander cycle oxygen/hydrogen engine technology component technology for the next space engine. The AETB will be used to validate the high-pressure expander cycle concept, investigate system interactions, and conduct investigations of advanced missions focused components and new health monitoring techniques. The split-expander cycle AETB will operate at combustion chamber pressures up to 1200 psia with propellant flow rates equivalent to 20,000 lbf vacuum thrust.

  17. Advanced expander test bed engine

    NASA Technical Reports Server (NTRS)

    Mitchell, J. P.

    1992-01-01

    The Advanced Expander Test Bed (AETB) is a key element in NASA's Space Chemical Engine Technology Program for development and demonstration of expander cycle oxygen/hydrogen engine and advanced component technologies applicable to space engines as well as launch vehicle upper stage engines. The AETB will be used to validate the high pressure expander cycle concept, study system interactions, and conduct studies of advanced mission focused components and new health monitoring techniques in an engine system environment. The split expander cycle AETB will operate at combustion chamber pressures up to 1200 psia with propellant flow rates equivalent to 20,000 lbf vacuum thrust.

  18. Internal circulating fluidized bed incineration system and design algorithm.

    PubMed

    Tian, W D; Wei, X L; Li, J; Sheng, H Z

    2001-04-01

    The internal circulating fluidized bed (ICFB) system is characterized with fast combustion, low emission, uniformity of bed temperature and controllability of combustion process. It is a kind of novel clean combustion system, especially for the low-grade fuels, such as municipal solid waste (MSW). The experimental systems of ICFB with and without combustion were designed and set up in this paper. A series of experiments were carried out for further understanding combustion process and characteristics of several design parameters for MSW. Based on the results, a design routine for the ICFB system was suggested for the calculation of energy balance, airflow rate, heat transfer rate, and geometry arrangement. A test system with ICFB combustor has been set up and the test results show that the design of the ICFB system is successful. PMID:11590739

  19. [Retention of selenium volatility using lime in coal combustion].

    PubMed

    Zhang, J; Ren, D; Zhong, Q; Xu, F; Zhang, Y; Yin, J

    2001-05-01

    For understanding the volatility of selenium, the effect of the contents of exchangeable cations of coal on it, and the retention of selenium using CaO in coal combustion, the sequential chemistry extraction, the fixed bed and circulating fluidized bed (CFB) combustion, X-ray diffraction (XRD) and atomic fluorescence spectrometry (AFS) were undertaken. The results showed that the volatility of selenium was more than 97% in coal combustion at 815 degrees C, and the volatility of selenium was affected by the content of exchangeable cations of coal in low-middle temperature. It was identified that lime can restrain the volatility of selenium. In fixed bed combustion of coal, the retention rates of selenium volatility were between 11.6% and 50.7% using lime. In circulating fluidized bed combustion of coal, partitioning of selenium changed very much in ash of different size fraction between without lime and with lime. Comparing with combustion without lime, the content of selenium in ash from chimney was less than fourth times and that in leaching water from chimney decreased by two orders of magnitude using lime. Retention of selenium volatility using lime is so effective in coal combustion, especially in CFB combustion of coal. PMID:11507891

  20. Burning coal refuse in fluid beds

    SciTech Connect

    Kleinau, J.H.; Sneyd, R.J.; Lombardi, C.E.

    1985-01-01

    This paper deals with the application of fluid bed combustion technology to the burning of coal-mining waste. The designs of two stage fluid bed combustors/dryers are demonstrated as useful in the drying of coal, slag and coke, using coal and coal refuse (gob) as fuel. Anthracite mining refuse (culm) is more than abundant in Northeastern Pennsylvania. After demonstration at Shamokin, Pennsylvania, a full commercial-sized fluid bed boiler using culm is used for district heating in Wilkes-Barre, Pennsylvania. Limited research work has shown the utility of using fine coal as filter aid in sludge incineration. With the rising avenues of the suitability of coal as auxiliary fuel in fluid bed sludge incineration, an expansion of these concepts combines the use of coal or coal refuse as filter aid and auxiliary fuel. Limestone addition controls SO/sub 2/ emission.

  1. Packed Bed Reactor Experiment

    NASA Video Gallery

    The purpose of the Packed Bed Reactor Experiment in low gravity is to determine how a mixture of gas and liquid flows through a packed bed in reduced gravity. A packed bed consists of a metal pipe ...

  2. Pulse Detonation Engine Test Bed Developed

    NASA Technical Reports Server (NTRS)

    Breisacher, Kevin J.

    2002-01-01

    A detonation is a supersonic combustion wave. A Pulse Detonation Engine (PDE) repetitively creates a series of detonation waves to take advantage of rapid burning and high peak pressures to efficiently produce thrust. NASA Glenn Research Center's Combustion Branch has developed a PDE test bed that can reproduce the operating conditions that might be encountered in an actual engine. It allows the rapid and cost-efficient evaluation of the technical issues and technologies associated with these engines. The test bed is modular in design. It consists of various length sections of both 2- and 2.6- in. internal-diameter combustor tubes. These tubes can be bolted together to create a variety of combustor configurations. A series of bosses allow instrumentation to be inserted on the tubes. Dynamic pressure sensors and heat flux gauges have been used to characterize the performance of the test bed. The PDE test bed is designed to utilize an existing calorimeter (for heat load measurement) and windowed (for optical access) combustor sections. It uses hydrogen as the fuel, and oxygen and nitrogen are mixed to simulate air. An electronic controller is used to open the hydrogen and air valves (or a continuous flow of air is used) and to fire the spark at the appropriate times. Scheduled tests on the test bed include an evaluation of the pumping ability of the train of detonation waves for use in an ejector and an evaluation of the pollutants formed in a PDE combustor. Glenn's Combustion Branch uses the National Combustor Code (NCC) to perform numerical analyses of PDE's as well as to evaluate alternative detonative combustion devices. Pulse Detonation Engine testbed.

  3. Biofuels combustion*

    DOE PAGESBeta

    Westbrook, Charles K.

    2013-01-04

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acidsmore » and used primarily to replace or supplement conventional diesel fuels. As a result, research efforts on so-called second- and third-generation biofuels are discussed briefly.« less

  4. Biofuels Combustion

    NASA Astrophysics Data System (ADS)

    Westbrook, Charles K.

    2013-04-01

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. Research efforts on so-called second- and third-generation biofuels are discussed briefly.

  5. Biofuels combustion*

    SciTech Connect

    Westbrook, Charles K.

    2013-01-04

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. As a result, research efforts on so-called second- and third-generation biofuels are discussed briefly.

  6. Bubble Combustion

    NASA Technical Reports Server (NTRS)

    Corrigan, Jackie

    2004-01-01

    A method of energy production that is capable of low pollutant emissions is fundamental to one of the four pillars of NASA s Aeronautics Blueprint: Revolutionary Vehicles. Bubble combustion, a new engine technology currently being developed at Glenn Research Center promises to provide low emissions combustion in support of NASA s vision under the Emissions Element because it generates power, while minimizing the production of carbon dioxide (CO2) and nitrous oxides (NOx), both known to be Greenhouse gases. and allows the use of alternative fuels such as corn oil, low-grade fuels, and even used motor oil. Bubble combustion is analogous to the inverse of spray combustion: the difference between bubble and spray combustion is that spray combustion is spraying a liquid in to a gas to form droplets, whereas bubble combustion involves injecting a gas into a liquid to form gaseous bubbles. In bubble combustion, the process for the ignition of the bubbles takes place on a time scale of less than a nanosecond and begins with acoustic waves perturbing each bubble. This perturbation causes the local pressure to drop below the vapor pressure of the liquid thus producing cavitation in which the bubble diameter grows, and upon reversal of the oscillating pressure field, the bubble then collapses rapidly with the aid of the high surface tension forces acting on the wall of the bubble. The rapid and violent collapse causes the temperatures inside the bubbles to soar as a result of adiabatic heating. As the temperatures rise, the gaseous contents of the bubble ignite with the bubble itself serving as its own combustion chamber. After ignition, this is the time in the bubble s life cycle where power is generated, and CO2, and NOx among other species, are produced. However, the pollutants CO2 and NOx are absorbed into the surrounding liquid. The importance of bubble combustion is that it generates power using a simple and compact device. We conducted a parametric study using CAVCHEM

  7. Low-rank coal research: Volume 3, Combustion research: Final report. [Great Plains

    SciTech Connect

    Mann, M. D.; Hajicek, D. R.; Zobeck, B. J.; Kalmanovitch, D. P.; Potas, T. A.; Maas, D. J.; Malterer, T. J.; DeWall, R. A.; Miller, B. G.; Johnson, M. D.

    1987-04-01

    Volume III, Combustion Research, contains articles on fluidized bed combustion, advanced processes for low-rank coal slurry production, low-rank coal slurry combustion, heat engine utilization of low-rank coals, and Great Plains Gasification Plant. These articles have been entered individually into EDB and ERA. (LTN)

  8. Simulation of fluidized bed coal combustors

    NASA Technical Reports Server (NTRS)

    Rajan, R.

    1979-01-01

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

  9. Combustion rates of chars from high-volatile fuels for FBC application

    SciTech Connect

    Masi, S.; Salatino, P.; Senneca, O.

    1997-12-31

    The fluidized bed combustion of high volatile fuels is often associated with huge occurrence of comminution phenomena. These result into in-bed generation of substantial amounts of carbon fines which further undergo competitive processes of combustion and elutriation. The small size of carbon fines generated by comminution is such that their further combustion is largely controlled by the intrinsic kinetics of carbon oxidation, alone or in combination with intraparticle diffusion. The competition between fine combustion and elutriation strongly affects the efficiency of fixed carbon conversion and calls for thorough characterization of the combustion kinetics and of residence times of fines in a fluidized bed of coarse solids. In this paper a collection of intrinsic combustion kinetic and porosimetric data for chars from three high-volatile fuels suitable for FBC application is presented. Chars from a Refuse Derived Fuel (RDF), a Tyre Derived Fuel (TDF) and a biomass (Robinia Pseudoacacia) are obtained from devolatilization, in fluidized bed, of fuel samples. Thermogravimetric analysis, mercury porosimetry and helium pycnometry are used to characterize the reactivity and the pore structure of the chars. Combustion rates are characterized over a wide range of temperatures (320--850 C) and oxygen partial pressures, covering the entire range of interest in fluidized bed combustion. Analysis of thermogravimetric and porosimetric data is directed to obtaining the parameters (pre-exponential factors, reaction orders, activation energies, intraparticle diffusivities) of combustion kinetic submodels for application in fluidized bed combustor modeling.

  10. Turbulent combustion

    SciTech Connect

    Talbot, L.; Cheng, R.K.

    1993-12-01

    Turbulent combustion is the dominant process in heat and power generating systems. Its most significant aspect is to enhance the burning rate and volumetric power density. Turbulent mixing, however, also influences the chemical rates and has a direct effect on the formation of pollutants, flame ignition and extinction. Therefore, research and development of modern combustion systems for power generation, waste incineration and material synthesis must rely on a fundamental understanding of the physical effect of turbulence on combustion to develop theoretical models that can be used as design tools. The overall objective of this program is to investigate, primarily experimentally, the interaction and coupling between turbulence and combustion. These processes are complex and are characterized by scalar and velocity fluctuations with time and length scales spanning several orders of magnitude. They are also influenced by the so-called {open_quotes}field{close_quotes} effects associated with the characteristics of the flow and burner geometries. The authors` approach is to gain a fundamental understanding by investigating idealized laboratory flames. Laboratory flames are amenable to detailed interrogation by laser diagnostics and their flow geometries are chosen to simplify numerical modeling and simulations and to facilitate comparison between experiments and theory.

  11. Fluidized bed heat exchanger with water cooled air distributor and dust hopper

    DOEpatents

    Jukkola, Walfred W.; Leon, Albert M.; Van Dyk, Jr., Garritt C.; McCoy, Daniel E.; Fisher, Barry L.; Saiers, Timothy L.; Karstetter, Marlin E.

    1981-11-24

    A fluidized bed heat exchanger is provided in which air is passed through a bed of particulate material containing fuel. A steam-water natural circulation system is provided for heat exchange and the housing of the heat exchanger has a water-wall type construction. Vertical in-bed heat exchange tubes are provided and the air distributor is water-cooled. A water-cooled dust hopper is provided in the housing to collect particulates from the combustion gases and separate the combustion zone from a volume within said housing in which convection heat exchange tubes are provided to extract heat from the exiting combustion gases.

  12. Mathematical modelling of coal fired fluidized bed combustors

    SciTech Connect

    Selcuk, N.; Siddall, R.G.; Sivrioglu, U.

    1980-12-01

    A system model of continuous fluidized bed combustors burning coal of wide size distribution has been derived, and applied to the investigation of the effect of excess air and recycle on bed concentration and temperature profiles and combustion efficiency of a pilot scale coal fired fluidized combustor. To demonstrate the effect of recycling, the behaviour of the fluidized combustor has been predicted for two extreme cases of recycle: complete and no recycle of elutriated char particles, the former was chosen to determine the behaviour of the model in the absence of elutriation, and the latter corresponds to the actual operating conditions of the fluidized combustor. Expected trends for concentration and temperature profiles and combustion efficiency are predicted correctly for both cases. The predictive ability and the flexibility of the model for incorporation of refinements such as a correlation for bubble growth and a detailed combustion mechanism, makes the model a promising one for the evaluation of performance of the fluid bed industrial boilers.

  13. Analysis of cyclic combustion of the coal-water suspension

    NASA Astrophysics Data System (ADS)

    Kijo-Kleczkowska, Agnieszka

    2011-04-01

    Combustion technology of the coal-water suspension creates a number of new possibilities to organize the combustion process fulfilling contemporary requirements, e.g. in the environment protection. Therefore the in-depth analysis is necessary to examine the technical application of coal as a fuel in the form of suspension. The research undertakes the complex investigations of the continuous coal-water suspension as well as cyclic combustion. The cyclic nature of fuel combustion results from the movement of the loose material in the flow contour of the circulating fluidized bed (CFB): combustion chamber, cyclone and downcomer. The experimental results proved that the cyclic change of oxygen concentration around fuel, led to the vital change of both combustion mechanisms and combustion kinetics. The mathematical model of the process of fuel combustion has been presented. Its original concept is based on the allowance for cyclic changes of concentrations of oxygen around the fuel. It enables the prognosis for change of the surface and the centre temperatures as well as mass loss of the fuel during combustion in air, in the fluidized bed and during the cyclic combustion.

  14. Anthracite culm fired fluidized-bed boiler

    SciTech Connect

    Lentz, E.C.

    1984-01-01

    The author describes a fluidised-bed boiler that has been designed by FluiDyne Engineering Corp. for the combustion of anthracite culm, a material containing about 40% ash and consisting of coal particles embedded in mineral matter. There are some 900 million tons of anthracite culm in northeast Pennsylvania within easy reach of many large metropolitan areas. It is estimated that the material can be used economically within a distance of 200 miles.

  15. NUCLA Circulating Atmospheric Fluidized Bed Demonstration Project

    SciTech Connect

    Not Available

    1992-02-01

    The objective of this DOE Cooperative Agreement is to conduct a cost-shared clean coal technology project to demonstrate the feasibility of circulating fluidized bed combustion technology and to evaluate economic, environmental, and operational benefits of CFB steam generators on a utility scale. At the conclusion of the Phase 2 program, testing related to satisfying these objectives was completed. Data analysis and reporting are scheduled for completion by October 1991. (VC)

  16. Regenerative combustion device

    DOEpatents

    West, Phillip B.

    2004-03-16

    A regenerative combustion device having a combustion zone, and chemicals contained within the combustion zone, such as water, having a first equilibrium state, and a second combustible state. Means for transforming the chemicals from the first equilibrium state to the second combustible state, such as electrodes, are disposed within the chemicals. An igniter, such as a spark plug or similar device, is disposed within the combustion zone for igniting combustion of the chemicals in the second combustible state. The combustion products are contained within the combustion zone, and the chemicals are selected such that the combustion products naturally chemically revert into the chemicals in the first equilibrium state following combustion. The combustion device may thus be repeatedly reused, requiring only a brief wait after each ignition to allow the regeneration of combustible gasses within the head space.

  17. AFBC bed material performance with low-rank coals

    SciTech Connect

    Goblirsch, G.M.; Benson, S.A.; Karner, F.R.; Rindt, D.K.; Hajicek, D.R.

    1983-01-01

    The purpose of this paper is to describe the reasons for carefully screening any candidate bed material for use in low-rank coal atmospheric fluidized-bed combustion, before the final selection is made. The sections of this paper describe: (1) the experimental equipment used to obtain the data, as well as the experimental and analytical procedures used in evaluation; (2) the results of tests utilizing various bed materials with particular emphasis on the problem of bed material agglomeration; and (3) the conclusions and recommendations for bed material selection and control for use with low-rank coal. Bed materials of aluminum oxide, quartz, limestone, dolomite, granite, gabbro, and mixtures of some of these materials have been used in the testing. Of these materials, gabbro appears most suitable for use with high available sodium lignites. 17 figures, 8 tables. (DMC)

  18. Advanced Combustion

    SciTech Connect

    Holcomb, Gordon R.

    2013-03-11

    The activity reported in this presentation is to provide the mechanical and physical property information needed to allow rational design, development and/or choice of alloys, manufacturing approaches, and environmental exposure and component life models to enable oxy-fuel combustion boilers to operate at Ultra-Supercritical (up to 650{degrees}C & between 22-30 MPa) and/or Advanced Ultra-Supercritical conditions (760{degrees}C & 35 MPa).

  19. 7 CFR 3201.15 - Bedding, bed linens, and towels.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 15 2012-01-01 2012-01-01 false Bedding, bed linens, and towels. 3201.15 Section 3201... PROCUREMENT Designated Items § 3201.15 Bedding, bed linens, and towels. (a) Definition. (1) Bedding is that..., bedspreads, comforters, and quilts. (2) Bed linens are woven cloth sheets and pillowcases used in bedding....

  20. 7 CFR 3201.15 - Bedding, bed linens, and towels.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Bedding, bed linens, and towels. 3201.15 Section 3201... PROCUREMENT Designated Items § 3201.15 Bedding, bed linens, and towels. (a) Definition. (1) Bedding is that..., bedspreads, comforters, and quilts. (2) Bed linens are woven cloth sheets and pillowcases used in bedding....

  1. 7 CFR 2902.15 - Bedding, bed linens, and towels.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Bedding, bed linens, and towels. 2902.15 Section 2902... PROCUREMENT Designated Items § 2902.15 Bedding, bed linens, and towels. (a) Definition. (1) Bedding is that..., bedspreads, comforters, and quilts. (2) Bed linens are woven cloth sheets and pillowcases used in bedding....

  2. 7 CFR 2902.15 - Bedding, bed linens, and towels.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 15 2011-01-01 2011-01-01 false Bedding, bed linens, and towels. 2902.15 Section 2902... PROCUREMENT Designated Items § 2902.15 Bedding, bed linens, and towels. (a) Definition. (1) Bedding is that..., bedspreads, comforters, and quilts. (2) Bed linens are woven cloth sheets and pillowcases used in bedding....

  3. 7 CFR 3201.15 - Bedding, bed linens, and towels.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Bedding, bed linens, and towels. 3201.15 Section 3201... PROCUREMENT Designated Items § 3201.15 Bedding, bed linens, and towels. (a) Definition. (1) Bedding is that..., bedspreads, comforters, and quilts. (2) Bed linens are woven cloth sheets and pillowcases used in bedding....

  4. Effects of coal combustion and gasification upon lung structure and function. Quarterly progress report, March 12, 1981

    SciTech Connect

    Not Available

    1981-01-01

    The overall objective of the proposed research is to correlate both structural and functional alterations in cells and tissues of the lung brought about by exposure to fluidized bed combustion and fixed bed gasification effluents and reagent grade oxides of metals known to be associated with coal combustion and gasification.

  5. Pulsed atmospheric fluidized bed combustor apparatus and process

    DOEpatents

    Mansour, Momtaz N.

    1992-01-01

    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.

  6. Fluidized-bed retrofit a practical alternative to FGD

    SciTech Connect

    Stringfellow, T.E.

    1984-02-01

    A comparison is made between the costs of flue-gas desulphurization retrofit to a 112 MW pf-fired boiler, fluidized-bed combustion retrofit to the boiler, and a new fluidized-bed boiler. Breakdowns are given for capital costs, operating and maintenance costs and the busbar cost of energy for a 20 year unit life. The analysis shows that fbc is a viable option for the retrofit of many existing boilers from both a technical and economic viewpoint.

  7. Numerical Simulation of Physical and Chemical Processes in Fluidized Bed

    NASA Astrophysics Data System (ADS)

    Baturin, D. A.; Gil, A. V.

    2015-10-01

    The paper presents a numerical simulation of the furnace with a circulating fluidized bed. Numerical study carried out for the bottom of the combustion chamber with the varying heights of volume filling. The results contours of particulate matter concentration and of velocities, as well as a graphical representation of changes in the concentration of particles on the bed height are shown. Simulation performed in Eulerian - Eulerian representation on a 2D model.

  8. Oil shale retorting and combustion system

    DOEpatents

    Pitrolo, Augustine A.; Mei, Joseph S.; Shang, Jerry Y.

    1983-01-01

    The present invention is directed to the extraction of energy values from l shale containing considerable concentrations of calcium carbonate in an efficient manner. The volatiles are separated from the oil shale in a retorting zone of a fluidized bed where the temperature and the concentration of oxygen are maintained at sufficiently low levels so that the volatiles are extracted from the oil shale with minimal combustion of the volatiles and with minimal calcination of the calcium carbonate. These gaseous volatiles and the calcium carbonate flow from the retorting zone into a freeboard combustion zone where the volatiles are burned in the presence of excess air. In this zone the calcination of the calcium carbonate occurs but at the expense of less BTU's than would be required by the calcination reaction in the event both the retorting and combustion steps took place simultaneously. The heat values in the products of combustion are satisfactorily recovered in a suitable heat exchange system.

  9. Oxy-coal Combustion Studies

    SciTech Connect

    Wendt, J.; Eddings, E.; Lighty, J.; Ring, T.; Smith, P.; Thornock, J.; Y Jia, W. Morris; Pedel, J.; Rezeai, D.; Wang, L.; Zhang, J.; Kelly, K.

    2012-01-06

    The objective of this project is to move toward the development of a predictive capability with quantified uncertainty bounds for pilot-scale, single-burner, oxy-coal operation. This validation research brings together multi-scale experimental measurements and computer simulations. The combination of simulation development and validation experiments is designed to lead to predictive tools for the performance of existing air fired pulverized coal boilers that have been retrofitted to various oxy-firing configurations. In addition, this report also describes novel research results related to oxy-combustion in circulating fluidized beds. For pulverized coal combustion configurations, particular attention is focused on the effect of oxy-firing on ignition and coal-flame stability, and on the subsequent partitioning mechanisms of the ash aerosol.

  10. Particle withdrawal from fluidized bed systems

    DOEpatents

    Salvador, Louis A.; Andermann, Ronald E.; Rath, Lawrence K.

    1982-01-01

    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.

  11. Practice Hospital Bed Safety

    MedlinePlus

    ... Bed? Todd says that there is no standard definition for hospital beds, a fact that consumers shopping ... in retail stores that don’t meet the definition of medical devices under the law, but which ...

  12. Enuresis (Bed-Wetting)

    MedlinePlus

    ... their development. Bed-wetting is more common among boys than girls. What causes bed-wetting? A number of things ... valves in boys or in the ureter in girls or boys Abnormalities in the spinal cord A small bladder ...

  13. Time for Bed Game

    MedlinePlus

    ... a Friend Who Cuts? Babysitting: Time for Bed Game KidsHealth > For Teens > Babysitting: Time for Bed Game Print A A A Text Size What Kids ... kids to bed can be tough sometimes! This game introduces children to the concept of getting enough ...

  14. Making a Bed

    ERIC Educational Resources Information Center

    Wexler, Anthony; Stein, Sherman

    2005-01-01

    The origins of this paper lay in making beds by putting pieces of plywood on a frame: If beds need to be 4 feet 6 inches by 6 feet 3 inches, and plywood comes in 4-foot by 8-foot sheets, how should one cut the plywood to minimize waste (and have stable beds)? The problem is of course generalized.

  15. Fluidized bed quenching technology

    SciTech Connect

    Reynoldson, R.

    1996-12-31

    The use of fluidized beds for quenching ferrous materials is outlined and compared with the more traditional techniques commonly used in the heat treatment industry. The use of fluidized bed quenching to control distortion of metal parts is also discussed. A case study is provided to illustrate a practical application of fluidized bed quenching.

  16. Fluidized-bed waste-heat recovery system development: Semiannual report, August 1, 1984-January 31, 1985

    SciTech Connect

    Cole, W.E.; Patch, K.D.

    1987-03-01

    A major energy loss in industry is the heat content of the flue gases from industrial process heaters. One effective way to utilize the energy is to preheat the combustion air for the process heater. The Fluidized-Bed Waste-Heat Recovery (FBWHR) System is designed to preheat this combustion air using the heat available in dirty flue gas streams. In this system, a recirculating medium is heated by the flue gas in a raining bed. The hot medium is then removed from the bed and placed in a fluidized bed where it is fluidized by the combustion air. Through this process, the combustion air is preheated. The cooled medium is then returned to the raining bed. Initial development of this concept is for the aluminum smelting industry. In this report, the accomplishments of the preceding six-month period are described. Specifically, tests in the laboratory FBWHR system, performing integrated system testing and subsystem development, were completed.

  17. Advanced expander test bed program

    NASA Technical Reports Server (NTRS)

    Riccardi, D. P.; Mitchell, J. C.

    1993-01-01

    The Advanced Expander Test Bed (AETB) is a key element in NASA's Space Chemical Engine Technology Program for development and demonstration of expander cycle oxygen/hydrogen engine and advanced component technologies applicable to space engines as well as launch vehicle upper stage engines. The AETB will be used to validate the high-pressure expander cycle concept, investigate system interactions, and conduct investigations of advanced mission focused components and new health monitoring techniques in an engine system environment. The split expander cycle AETB will operate at combustion chamber pressures up to 1200 psia with propellant flow rates equivalent to 20,000 lbf vacuum thrust. Contract work began 27 Apr. 1990. During 1992, a major milestone was achieved with the review of the final design of the oxidizer turbopump in Sep. 1992.

  18. Candle filter fabrication using combustion synthesis method

    SciTech Connect

    Hanus, G.J.; Uznanski, K.T.; DeCoursin, D.G.; Hickel, S.D.; Shtessel, E.

    1996-12-31

    Using self-propagating, high-temperature synthesis fabrication techniques, unique combinations of materials were studied for use in candle filter development. Materials suitable for corrosive atmospheres with improved filtration and mechanical properties were identified within the context of manufacturing simplicity, versatility and cost-effectiveness. Material combinations suitable for combustion synthesis were identified which match the temperature, strength and corrosion resistance requirements of operation in pressurized, fluidized-bed combustion environments. Tests on porosity, permeability and strength indicated the ability of the method to process porous filter material which matches or surpasses the performance levels of current, production candle filter material samples.

  19. Co-combustion of pellets from Soma lignite and waste dusts of furniture works

    SciTech Connect

    Deveci, N.D.; Yilgin, M.; Pehlivan, D.

    2008-07-01

    In this work, volatiles and char combustion behaviors of the fuel pellets prepared from a low quality lignite and the dusts of furniture works and their various blends were investigated in an experimental fixed bed combustion system through which air flowed by natural convection. Combustion data obtained for varied bed temperatures, mass of pellets, and blend compositions has showed that ignition times of the pellets decreased and volatiles combustion rates tended to increase with the burning temperature. It was concluded that some synergy had existed between lignite and lower ratios of furniture work dusts, which was indicated by a prompt effect on the volatiles combustion rates. Char combustion rates of blend pellets have depended predominantly on the amount of lignite in the blend. The amounts of combustion residues of the pellets were considerably higher than those calculated from individual ash contents of the raw materials and related to lignite ratio in the blends.

  20. Getting Rid of Bed Bugs

    MedlinePlus

    ... Bed Bugs — Do-it-yourself Bed Bug Control — Pesticides to Control Bed Bugs Bed Bug Information Clearinghouse ... Greener Living Health and Safety Land and Cleanup Pesticides Waste Water Science & Technology Air Climate Change Ecosystems ...

  1. Solid fuel combustion system for gas turbine engine

    DOEpatents

    Wilkes, Colin; Mongia, Hukam C.

    1993-01-01

    A solid fuel, pressurized fluidized bed combustion system for a gas turbine engine includes a carbonizer outside of the engine for gasifying coal to a low Btu fuel gas in a first fraction of compressor discharge, a pressurized fluidized bed outside of the engine for combusting the char residue from the carbonizer in a second fraction of compressor discharge to produce low temperature vitiated air, and a fuel-rich, fuel-lean staged topping combustor inside the engine in a compressed air plenum thereof. Diversion of less than 100% of compressor discharge outside the engine minimizes the expense of fabricating and maintaining conduits for transferring high pressure and high temperature gas and incorporation of the topping combustor in the compressed air plenum of the engine minimizes the expense of modifying otherwise conventional gas turbine engines for solid fuel, pressurized fluidized bed combustion.

  2. Sludge incineration in a spinning fluidized bed incinerator

    SciTech Connect

    Swithenbank, J.; Basire, S.; Wong, W.Y.; Lu, Y.; Nasserzadeh, V.

    1999-07-01

    At the present time, the sewage treatment plants in the UK produce about 25 million tonnes of sewage sludge each year at a concentration of 4% solids. New regulations forbid sea dumping and in the near future new incinerators will be required to dispose of about five million tonnes per year. Bubbling fluidized bed incinerators are widely used to burn sewage sludge at a typical consumption rate of about 0.02 kg(dry)/s/m{sup 2}, and it follows that over 300 conventional fluidized bed incinerators of 3 meters bed diameter could be required to cope with the increased demand. At Sheffield University Waste Incineration Centre (SUWIC) research work is being carried out to develop a novel spinning fluidized bed incinerator. The key factor to note is that when air flows up through a bed of near mono-sized particles, it fluidizes when the pressure drop across the bed is equal to the weight of the bed. Normally, the weight of the bed is determined by gravity. However, if the bed is contained by a cylindrical air distributor plate that is rotating rapidly about its axis, then the effective weight of the bed can be increased dramatically. The airflow passing through the bed can be increased proportionally to the g level produced by the rotation and it follows that the process has been intensified. In exploratory tests with a spinning fluidized bed the authors have achieved combustion intensities with coal combustion as high as 100 MW/m{sup 3}. A problem with burning coal is that it was difficult to remove the heat and rotating water seals had to be used to transfer cooling water into the bed. In the case of sewage and other sludges, this problem does not exist since the flue gases can remove the small amount of heat released. The rotating fluidized bed sludge incinerator is a novel device, which is very compact. It is able to solve the turndown problem encountered with conventional fluidized beds by simply changing the rotation speed. Bearing in mind that a centrifugal sludge

  3. Combustion chemistry

    SciTech Connect

    Brown, N.J.

    1993-12-01

    This research is concerned with the development and use of sensitivity analysis tools to probe the response of dependent variables to model input variables. Sensitivity analysis is important at all levels of combustion modeling. This group`s research continues to be focused on elucidating the interrelationship between features in the underlying potential energy surface (obtained from ab initio quantum chemistry calculations) and their responses in the quantum dynamics, e.g., reactive transition probabilities, cross sections, and thermal rate coefficients. The goals of this research are: (i) to provide feedback information to quantum chemists in their potential surface refinement efforts, and (ii) to gain a better understanding of how various regions in the potential influence the dynamics. These investigations are carried out with the methodology of quantum functional sensitivity analysis (QFSA).

  4. Moving Granular Bed Filter Development Program

    SciTech Connect

    Wilson, K.B.; Haas, J.C.; Eshelman, M.B.

    1992-01-01

    The granular bed filter was developed through low pressure, high temperature (1600[degrees]F) testing in the late 1970's and early 1980's'. Collection efficiencies over 99% were obtained. In 1988, high pressure, high temperature testing was completed at New York University, Westbury, N.Y., utilizing a coal-fired pressurized, fluidized bed combustor. High particulate removal efficiencies were confirmed as it was shown that both New Source Performance Standards and turbine tolerance limits could be met. The early scale-up work of the granular bed filter indicated potential limitations due to size, cost, and mechanical complexity. These limitations were addressed in the present program by utilizing the information gained from the filter development up through the NYU test program to reassess the commercial approach. Two studies were chosen for developing conceptual designs and cost estimates of the commercial sized filters. One is the economic study of the 250 MWe, second generation pressurized fluidized bed combustion plant defined by Foster Wheeler. This plant originally included cross-flow filters for hot gas cleanup. The other plant under study is a 100 MWe, airblown KRW gasifier. A cross-flow inter was utilized for gas stream cleanup in this study also. Granular bed and ceramic candle filters were substituted for the cross-flow filters in both these plants, and the resulting cost of electricity (COE) is compared.

  5. Moving Granular Bed Filter Development Program

    SciTech Connect

    Wilson, K.B.; Haas, J.C.; Eshelman, M.B.

    1992-11-01

    The granular bed filter was developed through low pressure, high temperature (1600{degrees}F) testing in the late 1970`s and early 1980`s`. Collection efficiencies over 99% were obtained. In 1988, high pressure, high temperature testing was completed at New York University, Westbury, N.Y., utilizing a coal-fired pressurized, fluidized bed combustor. High particulate removal efficiencies were confirmed as it was shown that both New Source Performance Standards and turbine tolerance limits could be met. The early scale-up work of the granular bed filter indicated potential limitations due to size, cost, and mechanical complexity. These limitations were addressed in the present program by utilizing the information gained from the filter development up through the NYU test program to reassess the commercial approach. Two studies were chosen for developing conceptual designs and cost estimates of the commercial sized filters. One is the economic study of the 250 MWe, second generation pressurized fluidized bed combustion plant defined by Foster Wheeler. This plant originally included cross-flow filters for hot gas cleanup. The other plant under study is a 100 MWe, airblown KRW gasifier. A cross-flow inter was utilized for gas stream cleanup in this study also. Granular bed and ceramic candle filters were substituted for the cross-flow filters in both these plants, and the resulting cost of electricity (COE) is compared.

  6. Generation and reduction of nitrogen oxides in firing different kinds of fuel in a circulating fluidized bed

    NASA Astrophysics Data System (ADS)

    Munts, V. A.; Munts, Yu. G.; Baskakov, A. P.; Proshin, A. S.

    2013-11-01

    The processes through which nitrogen oxides are generated and reduced in the course of firing different kinds of fuel in a circulating fluidized bed are addressed. All experimental studies were carried by the authors on their own laboratory installations. To construct a model simulating the generation of nitrogen oxides, the fuel combustion process in a fluidized bed was subdivided into two stages: combustion of volatiles and combustion of coke residue. The processes through which nitrogen oxides are generated and reduced under the conditions of firing fuel with shortage of oxygen (which is one of efficient methods for reducing nitrogen oxide emissions in firing fuel in a fluidized bed) are considered.

  7. Development of the instrumentation and modeling for heat transfer characteristics in CFBC. Technical progress report No. 2, April 1, 1996--September 30, 1996

    SciTech Connect

    Lee, Seong W.

    1996-11-01

    This technical report summarizes the research conducted and progress achieved during the period of April 1, 1996 to September 30, 1996. Auxiliary subsystems tests of the circulating fluidized bed were conducted and included the characteristics of a regenerative blower, a gas distributor, and a cyclone. When the air flow rate increases, the pressure at the blower outlet is decreased. The air flow rate in the riser is a function of the pressure in the wind box. The cyclone pressure drop and gas distributor pressure drop are functions of the primary air flow rate input. The higher gas pressure drop indicates primary air in the riser column with a uniform superficial velocity. The CFB primary test was conducted using glass beads as one of the CFB bed materials. Three typical tests with different sizes of glass were conducted. The pressure sensor data acquisition system was developed for the systematic instrumentation of flow measurements in the CFB system. Two types of sensors were used, a single pressure sensor, and a differential pressure sensor, respectively. The software used to control the analog/digital board was Paragon 500. The CFB experimental studies for hydrodynamics will be continued with the improved data acquisition system.

  8. Relationship between fluid bed aerosol generator operation and the aerosol produced

    SciTech Connect

    Carpenter, R.L.; Yerkes, K.

    1980-12-01

    The relationships between bed operation in a fluid bed aerosol generator and aerosol output were studied. A two-inch diameter fluid bed aerosol generator (FBG) was constructed using stainless steel powder as a fluidizing medium. Fly ash from coal combustion was aerosolized and the influence of FBG operating parameters on aerosol mass median aerodynamic diameter (MMAD), geometric standard deviation (sigma/sub g/) and concentration was examined. In an effort to extend observations on large fluid beds to small beds using fine bed particles, minimum fluidizing velocities and elutriation constant were computed. Although FBG minimum fluidizing velocity agreed well with calculations, FBG elutriation constant did not. The results of this study show that the properties of aerosols produced by a FBG depend on fluid bed height and air flow through the bed after the minimum fluidizing velocity is exceeded.

  9. Rates of pyrolysis and combustion of bark by thermogravimetric analysis

    SciTech Connect

    Chen, Wei-Yin

    1996-10-01

    Bark has been considered a viable renewable energy resource. This paper focuses on our experimental and modeling efforts on the bark combustion kinetics. Combustion and pyrolysis experiments have been conducted by lowering a sample-containing basket into a preheated, 2.5{double_prime} fluidized sand bed. This fluidized bed provides both rapid heating and quenching to the samples. Fluidized sand bed provides a very effective heat transfer medium between the gas (air or nitrogen) and the sand. Rapid quenching has been accomplished by raising the basket into a water-cooled, reversed-nitrogen flow section. The basket is made of a 40 mesh stainless steel screen. Combustion and pyrolysis of 10 mm diameter bark particles have been performed in the temperature ranges 500 to 800{degrees}C, and 750 to 850{degrees}C, respectively. The gas velocity has been in the range of 5.4 to 10.8 cm/s. Weight loss of bark after the experiments has been used as an index of conversion in the kinetic study. The combustion/pyrolysis model contains three dynamic equations: bark pyrolysis, char combustion, and heat transfer to bark particles. It has been assumed that the volatiles disengagement from char is governed by temperature-dependent desorption in an exponential form. By fitting the model to the experimental data, the seven parameters in the model have been recovered. These parameters include the four Arrhenius parameters for pyrolysis and combustion, total volatile at infinite temperature and temperature sensitivity in the volatile desorption equation, and heat of pyrolysis. Good agreement with the experimental data for pyrolysis and combustion demonstrates that the present model is capable of depicting the bark weight remaining in the bed at any time during combustion or pyrolysis. In addition, the kinetic parameters for the pyrolysis and heat of pyrolysis are in good accord with those in the literature.

  10. Lignite combustion test project interim report: Tests L101-L114

    SciTech Connect

    Phillips, K.E.; Wilson, K.B.

    1980-08-01

    Fluidized bed combustion research on North Dakota lignite is being performed by Combustion Power Company, Inc. under contract to Grand Forks Energy Technology Center in a 7 sq ft Atmospheric Fluid Bed Combustor. A series of 14 parameteric tests have been completed in which various combinations of bed temperature, superficial velocity, excess air, and limestone Ca/S ratios made up the test matrix. Twelve of the 14 tests used ash recycle. The test results extend the lignite combustion characteristics determined from GFETC tests on smaller reactors with respect to: (1) sulfur retention on lignite ash and supplemental sorbents; (2) ash and bed agglomeration problems; (3) effect of operational conditions and bed characteristics on heat transfer coeffficient; (4) ash reinjection; and (5) flue gas pollutants. This interim report summarizes the test setup, test procedures and test results, describes operational problems, and provides observations noted during the tests and on post-test inspections.

  11. Effects of effluents of coal combustion and gasification upon lung structure and function. Annual report

    SciTech Connect

    Hinton, D.E.

    1980-01-01

    The overall objective of the proposed research is to correlate both structural and functional alterations in cells and tissues of the lung brought about by exposure to fluidized bed combustion and fixed bed gasification effluents and reagent grade oxides of metals known to be associated with coal combustion gasification. Projected milestones are described. Progress during the first year in setting up aerosol exposure facilities, intratracheal instillations, pulmonary mechanics, and morphometric examinations is reported. (DMC)

  12. Model-free adaptive control of supercritical circulating fluidized-bed boilers

    SciTech Connect

    Cheng, George Shu-Xing; Mulkey, Steven L

    2014-12-16

    A novel 3-Input-3-Output (3.times.3) Fuel-Air Ratio Model-Free Adaptive (MFA) controller is introduced, which can effectively control key process variables including Bed Temperature, Excess O2, and Furnace Negative Pressure of combustion processes of advanced boilers. A novel 7-input-7-output (7.times.7) MFA control system is also described for controlling a combined 3-Input-3-Output (3.times.3) process of Boiler-Turbine-Generator (BTG) units and a 5.times.5 CFB combustion process of advanced boilers. Those boilers include Circulating Fluidized-Bed (CFB) Boilers and Once-Through Supercritical Circulating Fluidized-Bed (OTSC CFB) Boilers.

  13. FCC combustion zone catalyst cooling apparatus

    SciTech Connect

    Cetinkaya, I.B.; Myers, D.N.

    1987-12-01

    An apparatus for the combustion of a combustible material present on fluidized solid particles which apparatus is described comprises: (a) a vertically oriented combustion chamber having a cylindrical vertical sidewall, with an opening being located in the sidewall; (b) a disengagement chamber located superadjacent to the combustion chamber and in communication therewith, there being a hot fluid particle collection section located at the bottom of the disengagement chamber; (c) a cooling chamber surrounding at least one heat exchanger; (d) a hot particle conduit of vertical orientation connecting the hot particle collection section of the disengagement chamber with the cooling chamber particle inlet opening such that hot particles can flow downwardly from the disengagement chamber to the cooling chamber; (e) a particle flow restriction means in the hot particle conduit; (f) an open passageway connecting the particle outlet opening of the cooling chamber with the opening located in the sidewall of the combustion chamber and providing means for the flow of cooled particles and fluidizing gas from the heat exchanger to the combustion chamber; (g) a fluidizing gas inlet conduit connected to a bottom portion of the cooling chamber providing means for the passage of fluidizing gas onto the shell side of the heat exchanger and maintaining a fluidized catalyst bed within the cooling chamber; and, (h) a means to control the flow of fluidizing gas in the fluidizing gas inlet conduit.

  14. Combustion Fundamentals Research

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Increased emphasis is placed on fundamental and generic research at Lewis Research Center with less systems development efforts. This is especially true in combustion research, where the study of combustion fundamentals has grown significantly in order to better address the perceived long term technical needs of the aerospace industry. The main thrusts for this combustion fundamentals program area are as follows: analytical models of combustion processes, model verification experiments, fundamental combustion experiments, and advanced numeric techniques.

  15. Coal combustion science

    SciTech Connect

    Hardesty, D.R.; Baxter, L.L.; Fletcher, T.H.; Mitchell, R.E.

    1990-11-01

    The objective of this activity is to support the Office of Fossil Energy in executing research on coal combustion science. This activity consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center (PETC) Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency (IEA) Coal Combustion Science Project. Specific tasks include: coal devolatilization, coal char combustion, and fate of mineral matter during coal combustion. 91 refs., 40 figs., 9 tabs.

  16. Combustion technologies

    SciTech Connect

    Barsin, J.A.

    1994-12-31

    The presentation will cover the highlights of sludge, providing information as to where it comes from, projection of how much more is expected, what is sludge, what can be done with them, and finally focus in one combustion technology that can be utilized and applied to recycle sludge. The author is with Gotaverken Energy Systems Inc. where for the past 100 years they have been involved in the recovery of chemicals in chemical pulp mills. One week ago, our name was changed to Kvaerner Pulping Inc. to better reflect our present make-up which is a combination of Kamyr AB (suppliers of proprietary highly engineered totally chlorine free chemical pulp manufacturing systems, including digesters, O{sub 2} delignification systems, and bleach plant systems) and Goetaverken. Sludges that we are concerned with derive from several sources within chemical pulp mills such as: such as primary clarifier sludges, secondary clarifier sludges, and most recently those sludges derived from post consumer paper and board recycle efforts including de-inking and those from the thermal mechanical pulping processes. These sludges have been classified as non-hazardous therefore, residue can be landfilled, but the volumes involved are growing at an alarming rate.

  17. INVESTIGATION OF FUEL CHEMISTRY AND BED PERFORMANCE IN A FLUIDIZED BED BLACK LIQUOR STEAM REFORMER

    SciTech Connect

    Kevin Whitty

    2003-12-01

    The University of Utah project ''Investigation of Fuel Chemistry and Bed Performance in a Fluidized Bed Black Liquor Steam Reformer'' (DOE award number DE-FC26-02NT41490) was developed in response to a solicitation for projects to provide technical support for black liquor and biomass gasification. The primary focus of the project is to provide support for a DOE-sponsored demonstration of MTCI's black liquor steam reforming technology at Georgia-Pacific's paper mill in Big Island, Virginia. A more overarching goal is to improve the understanding of phenomena that take place during low temperature black liquor gasification. This is achieved through five complementary technical tasks: (1) construction of a fluidized bed black liquor gasification test system, (2) investigation of bed performance, (3) evaluation of product gas quality, (4) black liquor conversion analysis and modeling and (5) computational modeling of the Big Island gasifier. Four experimental devices have been constructed under this project. The largest facility, which is the heart of the experimental effort, is a pressurized fluidized bed gasification test system. The system is designed to be able to reproduce conditions near the black liquor injectors in the Big Island steam reformer, so the behavior of black liquor pyrolysis and char gasification can be quantified in a representative environment. The gasification test system comprises five subsystems: steam generation and superheating, black liquor feed, fluidized bed reactor, afterburner for syngas combustion and a flue gas cooler/condenser. The three-story system is located at University of Utah's Industrial Combustion and Gasification Research Facility, and all resources there are available to support the research.

  18. Experimental Replication of an Aeroengine Combustion Instability

    NASA Technical Reports Server (NTRS)

    Cohen, J. M.; Hibshman, J. R.; Proscia, W.; Rosfjord, T. J.; Wake, B. E.; McVey, J. B.; Lovett, J.; Ondas, M.; DeLaat, J.; Breisacher, K.

    2000-01-01

    Combustion instabilities in gas turbine engines are most frequently encountered during the late phases of engine development, at which point they are difficult and expensive to fix. The ability to replicate an engine-traceable combustion instability in a laboratory-scale experiment offers the opportunity to economically diagnose the problem (to determine the root cause), and to investigate solutions to the problem, such as active control. The development and validation of active combustion instability control requires that the causal dynamic processes be reproduced in experimental test facilities which can be used as a test bed for control system evaluation. This paper discusses the process through which a laboratory-scale experiment was designed to replicate an instability observed in a developmental engine. The scaling process used physically-based analyses to preserve the relevant geometric, acoustic and thermo-fluid features. The process increases the probability that results achieved in the single-nozzle experiment will be scalable to the engine.

  19. Development and applications of clean coal fluidized bed technology

    SciTech Connect

    Eskin, N.; Hepbasli, A.

    2006-09-15

    Power generation in Europe and elsewhere relies heavily on coal and coal-based fuels as the source of energy. The reliance will increase in the future due to the decreasing stability of price and security of oil supply. In other words, the studies on fluidized bed combustion systems, which is one of the clean coal technologies, will maintain its importance. The main objective of the present study is to introduce the development and the applications of the fluidized bed technology (FBT) and to review the fluidized bed combustion studies conducted in Turkey. The industrial applications of the fluidized bed technology in the country date back to the 1980s. Since then, the number of the fluidized bed boilers has increased. The majority of the installations are in the textile sector. In Turkey, there is also a circulating fluidized bed thermal power plant with a capacity of 2 x 160 MW under construction at Can in Canakkale. It is expected that the FBT has had, or will have, a significant and increasing role in dictating the energy strategies for Turkey.

  20. Combustion 2000

    SciTech Connect

    2000-06-30

    This report presents work carried out under contract DE-AC22-95PC95144 ''Combustion 2000 - Phase II.'' The goals of the program are to develop a coal-fired high performance power generation system (HIPPS) that is capable of: {lg_bullet} thermal efficiency (HHV) {ge} 47% {lg_bullet} NOx, SOx, and particulates {le} 10% NSPS (New Source Performance Standard) {lg_bullet} coal providing {ge} 65% of heat input {lg_bullet} all solid wastes benign {lg_bullet} cost of electricity {le} 90% of present plants Phase I, which began in 1992, focused on the analysis of various configurations of indirectly fired cycles and on technical assessments of alternative plant subsystems and components, including performance requirements, developmental status, design options, complexity and reliability, and capital and operating costs. Phase I also included preliminary R&D and the preparation of designs for HIPPS commercial plants approximately 300 MWe in size. Phase II, had as its initial objective the development of a complete design base for the construction and operation of a HIPPS prototype plant to be constructed in Phase III. As part of a descoping initiative, the Phase III program has been eliminated and work related to the commercial plant design has been ended. The rescoped program retained a program of engineering research and development focusing on high temperature heat exchangers, e.g. HITAF development (Task 2); a rescoped Task 6 that is pertinent to Vision 21 objectives and focuses on advanced cycle analysis and optimization, integration of gas turbines into complex cycles, and repowering designs; and preparation of the Phase II Technical Report (Task 8). This rescoped program deleted all subsystem testing (Tasks 3, 4, and 5) and the development of a site specific engineering design and test plan for the HIPPS prototype plant (Task 7). Work reported herein is from: {lg_bullet} Task 2.2.4 Pilot Scale Testing {lg_bullet} Task 2.2.5.2 Laboratory and Bench Scale Activities

  1. Combustion 2000

    SciTech Connect

    A. Levasseur; S. Goodstine; J. Ruby; M. Nawaz; C. Senior; F. Robson; S. Lehman; W. Blecher; W. Fugard; A. Rao; A. Sarofim; P. Smith; D. Pershing; E. Eddings; M. Cremer; J. Hurley; G. Weber; M. Jones; M. Collings; D. Hajicek; A. Henderson; P. Klevan; D. Seery; B. Knight; R. Lessard; J. Sangiovanni; A. Dennis; C. Bird; W. Sutton; N. Bornstein; F. Cogswell; C. Randino; S. Gale; Mike Heap

    2001-06-30

    . To achieve these objectives requires a change from complete reliance of coal-fired systems on steam turbines (Rankine cycles) and moving forward to a combined cycle utilizing gas turbines (Brayton cycles) which offer the possibility of significantly greater efficiency. This is because gas turbine cycles operate at temperatures well beyond current steam cycles, allowing the working fluid (air) temperature to more closely approach that of the major energy source, the combustion of coal. In fact, a good figure of merit for a HIPPS design is just how much of the enthalpy from coal combustion is used by the gas turbine. The efficiency of a power cycle varies directly with the temperature of the working fluid and for contemporary gas turbines the optimal turbine inlet temperature is in the range of 2300-2500 F (1260-1371 C). These temperatures are beyond the working range of currently available alloys and are also in the range of the ash fusion temperature of most coals. These two sets of physical properties combine to produce the major engineering challenges for a HIPPS design. The UTRC team developed a design hierarchy to impose more rigor in our approach. Once the size of the plant had been determined by the choice of gas turbine and the matching steam turbine, the design process of the High Temperature Advanced Furnace (HITAF) moved ineluctably to a down-fired, slagging configuration. This design was based on two air heaters: one a high temperature slagging Radiative Air Heater (RAH) and a lower temperature, dry ash Convective Air Heater (CAH). The specific details of the air heaters are arrived at by an iterative sequence in the following order:-Starting from the overall Cycle requirements which set the limits for the combustion and heat transfer analysis-The available enthalpy determined the range of materials, ceramics or alloys, which could tolerate the temperatures-Structural Analysis of the designs proved to be the major limitation-Finally the commercialization

  2. Separation of particulate from flue gas of fossil fuel combustion and gasification

    DOEpatents

    Yang, W.C.; Newby, R.A.; Lippert, T.E.

    1997-08-05

    The gas from combustion or gasification of fossil fuel contains fly ash and other particulates. The fly ash is separated from the gas in a plurality of standleg moving granular-bed filter modules. Each module includes a dipleg through which the bed media flows into the standleg. The bed media forms a first filter bed having an upper mass having a first frusto-conical surface in a frusto-conical member at the entrance to the standleg and a lower mass having a second frusto-conical surface of substantially greater area than the first surface after it passes through the standleg. A second filter media bed may be formed above the first filter media bed. The gas is fed tangentially into the module above the first surface. The fly ash is captured on the first frusto-conical surface and within the bed mass. The processed gas flows out through the second frusto-conical surface and then through the second filter bed, if present. The bed media is cleaned of the captured fly ash and recirculated to the moving granular bed filter. Alternatively, the bed media may be composed of the ash from the combustion which is pelletized to form agglomerates. The ash flows through the bed only once; it is not recycled. 11 figs.

  3. Separation of particulate from flue gas of fossil fuel combustion and gasification

    DOEpatents

    Yang, Wen-Ching; Newby, Richard A.; Lippert, Thomas E.

    1997-01-01

    The gas from combustion or gasification of fossil fuel contains flyash and other particulate. The flyash is separated from the gas in a plurality of standleg moving granular-bed filter modules. Each module includes a dipleg through which the bed media flows into the standleg. The bed media forms a first filter bed having an upper mass having a first frusto-conical surface in a frusto-conical member at the entrance to the standleg and a lower mass having a second frusto-conical surface of substantially greater area than the first surface after it passes through the standleg. A second filter media bed may be formed above the first filter media bed. The gas is fed tangentially into the module above the first surface. The flyash is captured on the first frusto-conical surface and within the bed mass. The processed gas flows out through the second frusto-conical surface and then through the second filter bed, if present. The bed media is cleaned of the captured flyash and recirculated to the moving granular bed filter. Alternatively, the bed media may be composed of the ash from the combustion which is pelletized to form agglomerates. The ash flows through the bed only once; it is not recycled.

  4. Integrated process for converting sulfur-containing fuels to low sulfur combustible gas

    SciTech Connect

    Moss, G.

    1981-03-10

    Sulfur-containing fuels are converted to substantially sulfurfree combustible gas in an integrated process involving part combustion in a dense phase fluidized conversion bed of particles comprising alkaline earth metal oxides. An oxygen-containing gas is passed into the base of the bed to maintain a relatively high fuel/air ratio. Sulfur is chemically fixed in the particles by reaction to form alkaline earth metal sulfide. Particles containing alkaline earth metal sulfide are circulated from one region of the conversion bed to one region of a dense phase fluidized regeneration bed operated at a higher temperature and fluidized by passing into the base thereof an oxygen-containing gas which exothermically regenerates chemically active alkaline earth metal oxide from the sulfide liberating gases which have a low oxygen content and a relatively high content of sulfur moieties (e.g. SO2). Hot particles are circulated from a second region of the regeneration bed to a second region of the conversion bed for use in fixing further quantities of sulfur from sulfur-containing fuel. Both beds contain a high molar proportion of unreacted alkaline earth metal oxide thereby imparting high sulfur-retaining capability to the conversion bed, and the beds interact cooperatively with each other at least in that particles entering the regeneration bed moderate temperatures therein and particles entering the conversion bed add heat thereto thereby reducing the fuel requirement for maintaining the conversion bed temperature.

  5. [Study on the calcium-based sorbent for removal fluorine during coal combustion].

    PubMed

    Li, Shu-ling; Qi, Qing-jie; Liu, Jian-zhong; Cao, Xin-yu; Zhou, Jun-hu; Cen, Ke-fa

    2004-03-01

    In the paper, the reaction of CaO-HF and fluorine removal mechanics at high temperature by blending calcium-based sorbents with coal during coal combustion were discussed, and test results about fluorine retention during coal combustion in fluidized bed and chain-grate furnace were reported. The results identified that lime and calcium-based sorbets developed can restratin the emission of fluorine during coal combustion. The efficiency of fluorine removal can reach 66.7%-70.0% at Ca/F 60-70 by blending lime with coal in fluidized bed combustion, and the efficiency of fluorine removal are between 57.32% and 75.19% by blending calcium-based sorbets with coal in chain-grate furnace combustion. Blending CaO or lime with coal during coal combustion can remove SO2 and HF simultaneously. PMID:15202259

  6. Predictive models for circulating fluidized bed combustors

    SciTech Connect

    Gidaspow, D.

    1989-11-01

    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.

  7. Fluidized bed boiler having a segmented grate

    DOEpatents

    Waryasz, Richard E.

    1984-01-01

    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.

  8. Fluidized bed calciner apparatus

    DOEpatents

    Owen, Thomas J.; Klem, Jr., Michael J.; Cash, Robert J.

    1988-01-01

    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.

  9. Volunteer Shelter Bed Programs.

    ERIC Educational Resources Information Center

    Little (Arthur D.), Inc., Washington, DC.

    The volunteer shelter bed program development guidelines in this booklet are offered as a community-based alternative to the institutionalization of status offenders. The volunteer shelter bed program is described as a nonsecure residential alternative for status offenders, which can be implemented without the creation of new facilities or the…

  10. Combustion 2000

    SciTech Connect

    1999-12-31

    This report presents work carried out under contract DE-AC22-95PC95144 ''Combustion 2000 - Phase II.'' The goals of the program are to develop a coal-fired high performance power generation system (HIPPS) that is capable of: {lg_bullet} thermal efficiency (HHV) {ge} 47% {lg_bullet} NOx, SOx, and particulates {le} 10% NSPS (New Source Performance Standard) {lg_bullet} coal providing {ge} 65% of heat input {lg_bullet} all solid wastes benign {lg_bullet} cost of electricity {le} 90% of present plants Phase I, which began in 1992, focused on the analysis of various configurations of indirectly fired cycles and on technical assessments of alternative plant subsystems and components, including performance requirements, developmental status, design options, complexity and reliability, and capital and operating costs. Phase I also included preliminary R&D and the preparation of designs for HIPPS commercial plants approximately 300 MWe in size. Phase II, had as its initial objective the development of a complete design base for the construction and operation of a HIPPS prototype plant to be constructed in Phase III. As part of a descoping initiative, the Phase III program has been eliminated and work related to the commercial plant design has been ended. The rescoped program retained a program of engineering research and development focusing on high temperature heat exchangers, e.g. HITAF development (Task 2); a rescoped Task 6 that is pertinent to Vision 21 objectives and focuses on advanced cycle analysis and optimization, integration of gas turbines into complex cycles, and repowering designs; and preparation of the Phase II Technical Report (Task 8). This rescoped program deleted all subsystem testing (Tasks 3, 4, and 5) and the development of a site-specific engineering design and test plan for the HIPPS prototype plant (Task 7). Work reported herein is from: {lg_bullet} Task 2.2.4 Pilot Scale Testing {lg_bullet} Task 2.2.5.2 Laboratory and Bench Scale Activities

  11. Pulsed atmospheric fluidized-bed combustor development. Environmental Assessment

    SciTech Connect

    Not Available

    1992-05-01

    Pulsed atmospheric fluidized-bed combustion (PAFBC) is a unique and innovative coal-fueled technology that has the potential to meet these conditions and provide heat and/or process steam to small industrial, commercial, institutional and residential complexes. The potential of Pulse Atmospheric Fluidized Bed Combustion (PAFBC) technology has been amply demonstrated under the sponsorship of a previous DOE/METC contract (DE-AC21-88MC25069). The environmental performance of a coal-fired laboratory-scale system (1.5 million British Thermal Units per hour) (MMBtu/hr) significantly surpassed that of conventional bubbling and circulating fluidized-bed combustion units (see Table 1 for performance comparison). Prompted by these encouraging results in combustion, sulfur capture, emissions control, and enhanced heat transfer, Island Creek Coal Company (ICC) and Baltimore Thermal Energy Corporation expressed interest in the technology and offered to participate by providing host sites for field testing. EA`s have been submitted independently for each of these field test sites. This submission addresses the preliminary testing of the PAFBC unit at Manufacturing and Technology Conversion International`s (MTCI) Baltimore, MD facility.

  12. Fundamentals of Gas Turbine combustion

    NASA Technical Reports Server (NTRS)

    Gerstein, M.

    1979-01-01

    Combustion problems and research recommendations are discussed in the areas of atomization and vaporization, combustion chemistry, combustion dynamics, and combustion modelling. The recommendations considered of highest priority in these areas are presented.

  13. Power plant efficiency and combustion optimization

    SciTech Connect

    Chatterjee, A.K.; Nema, N.; Jain, A.

    1998-07-01

    Grasim, a leader producer of Rayon grade staple fiber has, with time come up with its own Captive Electric Power Generation Industry with a capacity of generating 113 MW Thermal Power for its in-house use involving state of the art technology and system. In the present paper, it is desired to share the technical development in the global environment and receive expert feedback for its own upgrade. The on site power plants have a variety of steam turbines and boilers of different capacities. At times the plants had to face power crisis due to number of reasons and has always come up with number of solutions for performance enhancement and efficiency improvement. It is desired to present the following cases: (1) Development of spiral coal caps--for atmospheric fluidized bed boilers, it is often experienced that unburned carbon is high in ash. The reason being that coal particles do not get sufficient retention time after being injected into the bed. Attempt has been made to increase the retention time and better mixing by creating a cyclone around the coal cap with help of spiral coal caps. (2) Combustion optimization--in view of the inherent design deficiency, combustion was optimized by controlling the three parameters i.e., time, temperature and turbulence. In pulverized fuel combustion boilers this was done by providing air damper regulation and in atmospheric fluidized bed combustion boilers this was done by creating a vortex and regulating fluidizing air. The details shall be given in paper. (3) Power plant efficiency improvement--by introducing online monitoring system and identifying various areas of losses for various operating reasons and the cost associated with each operating parameter and the impact of each variation.

  14. Properties of Combustion Gases

    NASA Technical Reports Server (NTRS)

    Wear, J. D.; Jones, R. E.; Trout, A. M.; Mcbride, B. J.

    1986-01-01

    New series of reports: First report lists data from combustion of ASTM Jet A fuel and dry air; second report presents tables and figures for combustion-gas properties of natural-gas fuel and dry air, and equivalent ratios.

  15. Internal combustion engine with multiple combustion chambers

    SciTech Connect

    Gruenwald, D.J.

    1992-05-26

    This patent describes a two-cycle compression ignition engine. It comprises one cylinder, a reciprocable piston moveable in the cylinder, a piston connecting rod, a crankshaft for operation of the piston connecting rod, a cylinder head enclosing the cylinder, the upper surface of the piston and the enclosing surface of the cylinder head defining a cylinder clearance volume, a first combustion chamber and a second combustion chamber located in the cylinder head. This patent describes improvement in means for isolating the combustion process for one full 360{degrees} rotation of the crankshaft; wherein the combustion chambers alternatively provide for expansion of combustion products in the respective chambers into the cylinder volume near top dead center upon each revolution of the crankshaft.

  16. Maximal combustion temperature estimation

    NASA Astrophysics Data System (ADS)

    Golodova, E.; Shchepakina, E.

    2006-12-01

    This work is concerned with the phenomenon of delayed loss of stability and the estimation of the maximal temperature of safe combustion. Using the qualitative theory of singular perturbations and canard techniques we determine the maximal temperature on the trajectories located in the transition region between the slow combustion regime and the explosive one. This approach is used to estimate the maximal temperature of safe combustion in multi-phase combustion models.

  17. POLLUTANT FORMATION DURING FIXED-BED AND SUSPENSION COAL COMBUSTION

    EPA Science Inventory

    The report summarizes a 3-year study of the formation and control of nitrogen and sulfur oxides (NOx and SOx) in industrial coal-fired boilers, with emphasis on stoker-fired units. Three major research areas were considered: the evolution and oxidation of fuel nitrogen and sulfur...

  18. Mechanisms of droplet combustion

    NASA Technical Reports Server (NTRS)

    Law, C. K.

    1982-01-01

    The fundamental physico-chemical mechanisms governing droplet vaporization and combustion are discussed. Specific topics include governing equations and simplifications, the classical d(2)-Law solution and its subsequent modification, finite-rate kinetics and the flame structure, droplet dynamics, near- and super-critical combustion, combustion of multicomponent fuel blends/emulsions/suspensions, and droplet interaction. Potential research topics are suggested.

  19. INAA and PIXE of atmospheric and combustion aerosols.

    PubMed

    Kucera, J; Havránek, V; Smolík, J; Schwarz, J; Veselý, V; Kugler, J; Sýkorová, I; Santroch, J

    1999-01-01

    Using instrumental neutron activation analyses and photon-induced x-ray emission techniques for analysis of size-fractionated atmospheric and combustion aerosols and other emission samples arising from fluidized-bed combustion of North Bohemian lignites up to 42 elements were determined in all samples types. This allowed the evaluation of element enrichment, time trends, and inter-element correlations and the performance of factor analysis of various fractions of atmospheric aerosols. The data obtained on mass and element size distributions of aerosols and emission samples obtained upon lignite combustion in an experimental scale atmospheric fluidized-bed combustor without and with added hydrated lime and limestone were used to elucidate the mechanism of abatement of toxic trace and matrix elements from flue gas. PMID:10676497

  20. An Integrated Model of Coal/Coke Combustion in a Blast Furnace

    NASA Astrophysics Data System (ADS)

    Shen, Y. S.; Guo, B. Y.; Yu, A. B.; Austin, P.; Zulli, P.

    2010-03-01

    A three-dimensional integrated mathematical model of the combustion of pulverized coal and coke is developed. The model is applied to the region of lance-blowpipe-tuyere-raceway-coke bed to simulate the operation of pulverized coal injection in an ironmaking blast furnace. The model integrates two parts: pulverized coal combustion model in the blowpipe-tuyere-raceway-coke bed and the coke combustion model in the coke bed. The model is validated against the measurements in terms of coal burnout and gas composition, respectively. The comprehensive in-furnace phenomena are simulated in the raceway and coke bed, in terms of flow, temperature, gas composition, and coal burning characteristics. In addition, underlying mechanisms for the in-furnace phenomena are analyzed. The model provides a cost-effective tool for understanding and optimizing the in-furnace flow-thermo-chemical characteristics of the PCI process in full-scale blast furnaces.

  1. Particle fuel bed tests

    SciTech Connect

    Horn, F.L.; Powell, J.R.; Savino, J.M.

    1985-01-01

    Gas-cooled reactors, using packed beds of small diameter coated fuel particles have been proposed for compact, high-power systems. The particulate fuel used in the tests was 800 microns in diameter, consisting of a thoria kernel coated with 200 microns of pyrocarbon. Typically, the bed of fuel particles was contained in a ceramic cylinder with porous metallic frits at each end. A dc voltage was applied to the metallic frits and the resulting electric current heated the bed. Heat was removed by passing coolant (helium or hydrogen) through the bed. Candidate frit materials, rhenium, nickel, zirconium carbide, and zirconium oxide were unaffected, while tungsten and tungsten-rhenium lost weight and strength. Zirconium-carbide particles were tested at 2000 K in H/sub 2/ for 12 hours with no visible reaction or weight loss.

  2. Bed rest during pregnancy

    MedlinePlus

    ... provider before you start any activity: Squeezing stress balls Pressing your hands and feet against the bed ... limit yourself from doing any of these: Cooking Light chores Walking Bathing or showering Driving Having sex ...

  3. Tapered bed bioreactor

    DOEpatents

    Scott, Charles D.; Hancher, Charles W.

    1977-01-01

    A vertically oriented conically shaped column is used as a fluidized bed bioreactor wherein biologically catalyzed reactions are conducted in a continuous manner. The column utilizes a packing material a support having attached thereto a biologically active catalytic material.

  4. Combustion and core noise

    NASA Astrophysics Data System (ADS)

    Mahan, J. Robert; Karchmer, Allen

    1991-08-01

    Two types of aircraft power plant are considered: the gas turbine and the reciprocating engine. The engine types considered are: the reciprocating engine, the turbojet engine, the turboprop engine, and the turbofan engine. Combustion noise in gas turbine engines is discussed, and reciprocating-engine combustion noise is also briefly described. The following subject areas are covered: configuration variables, operational variables, characteristics of combustion and core noise, sources of combustion noise, combustion noise theory and comparison with experiment, available prediction methods, diagnostic techniques, measurement techniques, data interpretation, and example applications.

  5. Combustion characteristics and arsenic retention during co-combustion of agricultural biomass and bituminous coal.

    PubMed

    Zhou, Chuncai; Liu, Guijian; Wang, Xudong; Qi, Cuicui; Hu, Yunhu

    2016-08-01

    A combination of thermogravimetric analysis (TG) and laboratory-scale circulated fluidized bed combustion experiment was conducted to investigate the thermochemical, kinetic and arsenic retention behavior during co-combustion bituminous coal with typical agricultural biomass. Results shown that ignition performance and thermal reactivity of coal could be enhanced by adding biomass in suitable proportion. Arsenic was enriched in fly ash and associated with fine particles during combustion of coal/biomass blends. The emission of arsenic decreased with increasing proportion of biomass in blends. The retention of arsenic may be attributed to the interaction between arsenic and fly ash components. The positive correlation between calcium content and arsenic concentration in ash suggesting that the arsenic-calcium interaction may be regarded as the primary mechanism for arsenic retention. PMID:27136608

  6. Refractory experience in circulating fluidized bed combustors, Task 7

    SciTech Connect

    Vincent, R.Q.

    1989-11-01

    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.

  7. Test Bed For Telerobots

    NASA Technical Reports Server (NTRS)

    Matijevic, Jacob R.; Zimmerman, Wayne F.; Dolinsky, Shlomo

    1990-01-01

    Assembly of electromechanical and electronic equipment (including computers) constitutes test bed for development of advanced robotic systems for remote manipulation. Combines features not found in commercial systems. Its architecture allows easy growth in complexity and level of automation. System national resource for validation of new telerobotic technology. Intended primarily for robots used in outer space, test bed adapted to development of advanced terrestrial telerobotic systems for handling radioactive materials, dangerous chemicals, and explosives.

  8. Bed rest and immunity

    NASA Astrophysics Data System (ADS)

    Sonnenfeld, Gerald; Aviles, Hernan; Butel, Janet S.; Shearer, William T.; Niesel, David; Pandya, Utpal; Allen, Christopher; Ochs, Hans D.; Blancher, Antoine; Abbal, Michel

    2007-02-01

    Space flight has been shown to result in altered immune responses. The current study was designed to investigate this possibility by using the bed rest model of some space flight conditions. A large number of women are included as subjects in the study. The hypothesis being tested is: 60 days head-down tilt bed rest of humans will affect the immune system and resistance to infection. Blood, urine and saliva samples will be obtained from bed rest subjects prior to, at intervals during, and after completion of 60 days of head-down tilt bed rest. Leukocyte blastogenesis, cytokine production and virus reactivation will be assessed. The ability of the subjects to respond appropriately to immunization with the neoantigen bacteriophage φX-174 will also be determined. Bed rest is being carried out at MEDES, Toulouse France, and the University of Texas Medical Branch, Galveston, TX. The studies to be carried out in France will also allow assessment of the effects of muscle/bone exercise and nutritional countermeasures on the immune system in addition to the effects of bed rest.

  9. An optical method of measuring the temperature in a fluidised bed combustor

    SciTech Connect

    Zukowski, Witold; Baron, Jerzy; Bulewicz, Elzbieta M.; Kowarska, Beata

    2009-07-15

    The paper analyses the dynamic aspects of the temperature field in a fluidised bed of solids particles (e.g., sand) in which a gaseous fuel is being burned. Such a hot bed emits electromagnetic radiation within the visible range and this can be recorded using a digital video camera. This fact has been used to develop a method for measuring the bed's temperature in the line of sight, through the quartz sides of the reactor. A solid probe is only used for calibration. Video recordings were obtained covering different regions of the bed over three wavelength bands, red, green and blue. In the course of an experiment, the mean temperature of the bed, measured with thermocouples, was raised from ambient to 1300 K, at a rate of {proportional_to} 1 K/s. The data collected were used for calibration, with the brightness of individual pixels converted to a temperature scale. The calibration can then be used to investigate the dynamic temperature distribution within the field of view, in individual elements of the bed. This can also help the study of heat transfer in the bed, its distribution and dissipation. Using this method, it is possible to make direct observations of the intermittent combustion of gaseous fuels in a bubbling fluidised bed. The results provide direct proof that the temperature gradients observed within such beds are associated with exothermic processes within fast moving bubbles. The method could be adapted to studying, e.g., the combustion of solid fuels. (author)

  10. Combustion, pyrolysis, gasification, and liquefaction of biomas

    NASA Astrophysics Data System (ADS)

    Reed, T. B.

    1980-09-01

    The advantages of biomass as a feedstock are examined and biomass conversion techniques are described. Combustion is the simplest method of producing heat from biomass, using either the traditional fixed bed combustion on a grate or the fluidized bed and suspended combustion techniques now being developed. Pyrolysis of biomass is a particularly attractive process if all three products gas, wood tars, and charcoal can be used. Gasification of biomass with air is perhaps the most flexible and best developed process for conversion of biomass to fuel, yielding a low energy gas that can be burned in existing gas/oil boilers or in engines. Oxygen gasification yields a gas with higher energy content that can be used in pipelines or to fire turbines. In addition, this gas can be used for producing methanol, ammonia, or gasoline by indirect liquefaction. Fast pyrolysis of biomass produces a gas rich in ethylene that can be used to make alcohols or gasoline. Finally, treatment of biomass with high pressure hydrogen can yield liquid fuels through direct liquefaction.

  11. The coal slime slurry combustion technology

    SciTech Connect

    Li, Y.; Xu, Z.

    1997-12-31

    This paper presents the coal slime slurry combustion technology in circulating fluidized bed (CFB) boilers. The technique is that the slurry-based flow from the concentrator in the coal washery plant directly feeds into the fluidized bed by pump for combustion after a simple filtration and enrichment to an approximate concentration of 50% of coal. The coal slime slurry can burn in a CFB boiler alone or jointly with coal refuse. The technique has been used in a 35 t/h (6MWe) CFB for power generation. The result shows that the combustion efficiency is over 96% and boiler thermal efficiency is over 77%. As compared with burning coal refuse alone, the thermal efficiency was improved by 3--4 percent. This technology is simple, easy to operate and reliable. It is an effective way to utilize coal slime slurry. It has a practical significance for saving coal resources and reducing environmental pollution near coal mine areas. As a clean coal technology, it will result in great social, environmental and economic benefits.

  12. Combustion, pyrolysis, gasification, and liquefaction of biomass

    SciTech Connect

    Reed, T.B.

    1980-09-01

    All the products now obtained from oil can be provided by thermal conversion of the solid fuels biomass and coal. As a feedstock, biomass has many advantages over coal and has the potential to supply up to 20% of US energy by the year 2000 and significant amounts of energy for other countries. However, it is imperative that in producing biomass for energy we practice careful land use. Combustion is the simplest method of producing heat from biomass, using either the traditional fixed-bed combustion on a grate or the fluidized-bed and suspended combustion techniques now being developed. Pyrolysis of biomass is a particularly attractive process if all three products - gas, wood tars, and charcoal - can be used. Gasification of biomass with air is perhaps the most flexible and best-developed process for conversion of biomass to fuel today, yielding a low energy gas that can be burned in existing gas/oil boilers or in engines. Oxygen gasification yields a gas with higher energy content that can be used in pipelines or to fire turbines. In addition, this gas can be used for producing methanol, ammonia, or gasoline by indirect liquefaction. Fast pyrolysis of biomass produces a gas rich in ethylene that can be used to make alcohols or gasoline. Finally, treatment of biomass with high pressure hydrogen can yield liquid fuels through direct liquefaction.

  13. Control of bed height in a fluidized bed gasification system

    DOEpatents

    Mehta, Gautam I.; Rogers, Lynn M.

    1983-12-20

    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.

  14. Opportunities in pulse combustion

    NASA Astrophysics Data System (ADS)

    Brenchley, D. L.; Bomelburg, H. J.

    1985-10-01

    In most pulse combustors, the combustion occurs near the closed end of a tube where inlet valves operate in phase with the pressure amplitude variations. Thus, within the combustion zone, both the temperature and the pressure oscillate around a mean value. However, the development of practical applications of pulse combustion has been hampered because effective design requires the right combination of the combustor's dimensions, valve characteristics, fuel/oxidizer combination, and flow pattern. Pulse combustion has several additional advantages for energy conversion efficiency, including high combustion and thermal efficiency, high combustion intensity, and high convective heat transfer rates. Also, pulse combustion can be self-aspirating, generating a pressure boost without using a blower. This allows the use of a compact heat exchanger that may include a condensing section and may obviate the need for a chimney. In the last decade, these features have revived interest in pulse combustion research and development, which has resulted in the development of a pulse combustion air heater by Lennox, and a pulse combustion hydronic unit by Hydrotherm, Inc. To appraise this potential for energy savings, a systematic study was conducted of the many past and present attempts to use pulse combustion for practical purposes. The authors recommended areas where pulse combustion technology could possibly be applied in the future and identified areas in which additional R and D would be necessary. Many of the results of the study project derived from a special workshop on pulse combustion. This document highlights the main points of the study report, with particular emphasis on pulse combustion application in chemical engineering.

  15. Moving Granular Bed Filter Development Program

    SciTech Connect

    Wilson, K.B.; Haas, J.C.; Gupta, R.P.; Turk, B.S.

    1996-12-31

    For coal-fired power plants utilizing a gas turbine, the removal of ash particles is necessary to protect the turbine and to meet emission standards. Advantages are also evident for a filter system that can remove other coal-derived contaminants such as alkali, halogens, and ammonia. With most particulates and other contaminants removed, erosion and corrosion of turbine materials, as well as deposition of particles within the turbine, are reduced to acceptable levels. The granular bed filter is suitable for this task in a pressurized gasification or combustion environment. The objective of the base contract was to develop conceptual designs of moving granular bed filter (GBF) and ceramic candle filter technologies for control of particles from integrated gasification combined cycle (IGCC), pressurized fluidized-bed combustion (PFBC), and direct coal-fueled turbine (DCFT) systems. The results of this study showed that the GBF design compared favorably with the candle filter. Three program options followed the base contract. The objective of Option I, Component Testing, was to identify and resolve technical issues regarding GBF development for IGCC and PFBC environments. This program was recently completed. The objective of Option II, Filter Proof Tests, is to test and evaluate the moving GBF system at a government-furnished hot-gas cleanup test facility. This facility is located at Southern Company Services (SCS), Inc., Wilsonville, Alabama. The objective of Option III, Multicontaminant Control Using a GBF, is to develop a chemically reactive filter material that will remove particulates plus one or more of the following coal-derived contaminants: alkali, halogens, and ammonia.

  16. Apparatus for fixed bed coal gasification

    DOEpatents

    Sadowski, Richard S.

    1992-01-01

    An apparatus for fixed-bed coal gasification is described in which coal such as caking coal is continuously pyrolyzed with clump formation inhibited, by combining the coal with a combustible gas and an oxidant, and then continually feeding the pyrolyzed coal under pressure and elevated temperature into the gasification region of a pressure vessel. The materials in the pressure vessel are allowed to react with the gasifying agents in order to allow the carbon contents of the pyrolyzed coal to be completely oxidized. The combustion of gas produced from the combination of coal pyrolysis and gasification involves combining a combustible gas coal and an oxidant in a pyrolysis chamber and heating the components to a temperature of at least 1600.degree. F. The products of coal pyrolysis are dispersed from the pyrolyzer directly into the high temperature gasification region of a pressure vessel. Steam and air needed for gasification are introduced in the pressure vessel and the materials exiting the pyrolyzer flow down through the pressure vessel by gravity with sufficient residence time to allow any carbon to form carbon monoxide. Gas produced from these reactions are then released from the pressure vessel and ash is disposed of.

  17. Granular bed emission control of a fluid-bed bark combustor

    SciTech Connect

    Tollett, R.M.; Turchina, A.V.; Ostendorf, R.G.; Navratil, L.G.

    1985-01-01

    Various additive mixtures were evaluated for effects on modifying resistivity of aspen bark ash. This had a direct effect on the efficiency of the Electroscrubber Filter (ESF) which is an electrically enhanced granular bed filter. Increased efficiencies were demonstrated in full scale testing at the Procter and Gamble plant in Green Bay, Wisconsin. Since July, 1984, emission tests have shown results below 0.04 number/MM BTU. The ESF was installed in 1983 on an EPI fluid-bed combuster burning aspen bark. In the first year of operation the ESF had trouble maintaining grid voltage. As with electrostatic precipitators, Electroscrubbers are sensitive to the resistivity of the ash collected but in an opposite way. Low resistivity is good for an electrostatic precipitator (ESP), but bad for an Electroscrubber. This paper discusses the importance of resistivity and the theoretical aspects of an Electroscrubber type of device.

  18. Combustion modeling in internal combustion engines

    NASA Technical Reports Server (NTRS)

    Zeleznik, F. J.

    1976-01-01

    The fundamental assumptions of the Blizard and Keck combustion model for internal combustion engines are examined and a generalization of that model is derived. The most significant feature of the model is that it permits the occurrence of unburned hydrocarbons in the thermodynamic-kinetic modeling of exhaust gases. The general formulas are evaluated in two specific cases that are likely to be significant in the applications of the model.

  19. Boiler using combustible fluid

    DOEpatents

    Baumgartner, H.; Meier, J.G.

    1974-07-03

    A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.

  20. Status of the fluidized bed unit

    SciTech Connect

    Williams, P.M.; Wade, J.F.

    1994-06-01

    Rocky Flats has a serious mixed waste problem. No technology or company has a license and available facilities to remedy this dilemma. One solution under study is to use a catalytic fluidized bed unit to destroy the combustible portion of the mixed waste. The fluidized bed thermal treatment program at Rocky Flats is building on knowledge gained over twenty years of successful development activity. The FBU has numerous technical advantages over other thermal technologies to treat Rocky Flats` mixed waste, the largest being the lower temperature (700{degrees}C versus 1000{degrees}C) which reduces acid corrosion and mechanical failures and obviates the need for ceramic lining. Successful demonstrations have taken place on bench, pilot, and full-scale tests using radioactive mixed wastes. The program is approaching implementation and licensing of a production-scale fluidized bed system for the safe treatment of mixed waste. The measure for success on this project is the ability to work closely with the community to jointly solve problems and respond to concerns of mixed waste treatment at Rocky Flats.