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03492 Copper-based sorbents for hot coal gas desulfurization systems
07 Beneficiation 97103480 classified fuel Kudinov, G. G. and Kazimirov, Russian)
of
anthracites
V. D.
and
production
Ugol’ U/o., 1996, (12)
of
15-19. (In
Benefits of advanced coal cleaning in MCWS 97t934al preparation Itvokumbul. M. T. et al. Proc. Int. Tech. Corrf. Coal Util. Fuel Syst., 1994, 19, 565-5 74. In order to obtain the desired particle size distribution, the coal is pulverized in micronized coal water slurry preparation (MCWS). The need for introducing a precleaning stage prior to the final slurry formulation and the potential advantages and disadvantages of an integrated cleaning/size reduction process are discussed. 97193402 Cireddu, P.
Characteristic
et al.
of coal water slurries
for gasifiers.
Proc. Int. Tech. Conf. Coal Util. Fuel Syst.. 1993. 18, J83-
797.
Studies the preparation of Sulcis (Italy) coal water slurries for gasification by using wet ball mill grinding. Closed-water circuitry of a coal preparation plant 97163403 with jig-flotation process Peizao. S. and Baexin, G. Proc. In/. Tech. Conf. Coal Util. Fuel Syst., 1993.
IX. 60I-606. The paper describes the coal preparation system with its jig circuit treating coal down to submillimetre. It can be operated with closed-water circuit by fully using the function of compressed air in jigging and by mini introduction of under-screen water. Coal beneficiation-sulfur removal using methanol 97193484 Wang, G. and Trass, 0. Proc. In/. Tech. Cortf: Coal Util. Fuel Syrt.. 1997, 22. 5 13-520.
A 300 ml hatch reactor was used to study sulfur removal from coal by methanol. Illinois IBC-108 coal is highly beneficiated and contains mainly organic sulfur: the results can also be applied to organic sulfur removal. Temperature. reaction time and methanol level increased sulfur removal. However. coal level decreased sulfur removal. Coal pyrolysis was explored in both open and closed systems. The best results gave a total sulfur removal of 86% (90% for organic) at 500°C. 60-90 min reaction time and very small amounts of coal, with a weight loss of about 30%. Total sulfur removal is presented in an empirical correlation. Coal characterization and high gradient magnetic 97103485 separation studies of coal fines from Paradise Kentucky Harvey, C. C. et al. Proc. In/. Tech. Conf: Coal Util. Fuel Syst.. 1997, 22, flos-616. Selected samples of five characterized coal slurry ponds at the TVA Paradise facility in Western Kentucky were subjected to high gradient magnetic separation (HGMS) studies. The objective was to determine whether or not HGMS is an effective technique for pyritic sulfur and ash removal from coal fines. Wet HGMS studies were conducted over a range of concentrations, and at different field strengths of up to 2 T (20,000 G). Various matrices were used in the magnet. Grinding to finer particle sizes liberates the pyrite and ash-forming minerals, enhancing their separation in the magnet. At particle sizes greater than 200 mesh clogging occurred within the magnet when the finer wool matrix was used. Tests are currently underway at higher field strengths of 6 T. By a single pass through the magnet the sulfur content of the coal fines was reduced by between 1.5 and 2% while the ash content also reduced by 7%. Additional sulfur removal was possible with second and third passes, but the sulfur reductions were lower. Excessive abundance of ash-forming minerals (above 40%) limited the effectiveness of the magnet. A front end process to remove the majority of the ash-forming minerals and provide a fine feed for the magnet, should enhance the effectiveness of HGMS. Therefore, HGMS may be more effective as a polishing step following more conventional coal cleaning technologies. Coal cleaning: an underutilized solution? 97103466 Godfrey, R. L. Proc. In/. Tech. Conf: Coal Util. Fuel Syst., 1995, 20, 709120.
The author reports the activities of the most advanced facilities of Custom Coals Corporation of Pittsburgh, PA.
coal
cleaning
Coal pond fines cleaning with classifying cyclones, 97103407 spirals, and column flotation Carson, W. R. et al. Proc. In/. Tech. Conf: Coal U/i/. Fuel Syst., 1997, 22, 585-596.
The Illinois Basin is the location of large reserves of coal pond fines which, if used to produce coal-water slurry (CWS), could reduce fuel costs, NO, emissions, and pond closure costs. Coal fines from this region for production of CWS for co-fire or re-burn may require processing to attain proper particle size distribution and fuel quality. To evaluate the effectiveness of using coal cleaning technologies to control these CWS quality parameters, a simple flowsheet for recovering and processing coal pond fines was designed and tested. Coal fines processing comprised classifying cyclones to size at nominal minus 200 mesh, cleaning the classifying cyclone underflow using spirals, and cleaning the overflow using
Solid fuels (preparation)
column froth flotation. Ash content of the clean coal from the spiral was reduced to -lo%, a satisfactory level for CWS co-firing in a cyclone-fired boiler. The clean coal from column flotation may be used for re-burn in a cyclone-fired boiler or as co-fire fuel in a wall-fired or tangentially-fired boiler. Heating value recovery of -80% was achieved during laboratory scale, pilot-scale, and commercial-scale coal cleaning testing. 97103488 Coal slurry dewatering at Mohave Generating Statlon Duey, B. Proc. In/. Tech. Conf. Coal Util. Fuel Syst., 1994, 19, 473-484. The Black Mesa pipeline (275 mi) and coal slurry dewatering at the station are described. 97103489 Coal upgrading in a MagMill Oder, R. R. et al. Proc. In/. Tech. Conf. Coal Util. Fuel Syst., 1996, 21 1317326.
In order to remove non-combustible minerals and to lower the concentration of pollutants, such as sulfur and heavy metals, many coals are wetcleaned at the mine. Due to the high cost of pulverizing, cleaning, dewatering, and shipping fine sized coal, this cleaning is carried out at the coarsest practicable size which consequently limits the effectiveness of wet coal cleaning. This paper reports results of an on-going programme to develop the MagMill, a practical dry coal cleaning technology. It is an innovative method which combines pulverization and magnetic beneficiation in one unit. 97103490 Composition, structure and pyrolysis of cyclohexanone extracts of Yanzhou coal Chen. C. et al. Ranliao Huaxue Xuehno. 1997. 25, (2), 135-138. (In Chinese) A new solvent for coal extraction is presented, called cyclohexanone. The extracts of high extraction yield and high molecular weight are available for investigating the coal molecular structure. Preasphaltenes and asphaltenes are the main components of the extracts The structure analysis by FTIR and lH-NMR showed that preasphaltenes, compared with asphaltenes, had a higher aromaticity (0.12 for preasphaltene and 0.63 for asphaltene) and more bridge methylene but less side alkyl. The pyrolysis reaction of the extracts occurred at 200-600°C and the main pyrolysis product of the extracts was tar. 97103491 Control of hazardous air pollutant precursors by advanced coal preparation Luttrell, G. H. et al. Pollut. Prev. Process Eng., Proc. Tech. Solutions Pollut. Prev. Min. Miner. Process. Ind., Eng. Found. Conf., 1995, (Pub. 1996), I1 l120. Edited by Richardson, P. E. C. and Schemer, B. J., Engineering Foundation, New York, NY. New emission standards for 189 potentially hazardous air pollutants will be established under implementation of the 1990 Clean Air Act Amendment. Several of these, such as arsenic, mercury and selenium, are present as trace elements in run-of-mine coals, Research conducted at Virginia Tech suggests that many of these elements can be efficiently rejected prior to coal combustion using a two-stage physical cleaning circuit that combines advanced froth flotation with an enhanced gravity separator. By combining both units in a single circuit, improved rejections of a wide variety of trace elements can be achieved. This paper describes the findings of recent pilotscale test work conducted to evaluate the capabilities of this novel two-stage circuit for removing trace elements from an Illinois No. 6 coal. 97103492 Copper-based sorbents for hot coal gas desulfurization systems Abbasian, J. et al. Proc. In/. Tech. Conf: Coal Util. Fuel Syst., 1997. 22, 7182.
IGT has developed a copper-chromite sorbent for hot coal gas desulfurization. The results obtained so far indicate that this sorbent, in granular form, has a much higher attrition resistance compared to the commercial granular zinc titanate sorbent, as well as excellent desulfurization efficiency. Furthermore, the reactivity of IGT’s CuCr-29 sorbent gradually and consistently improved during the 20 cycles tested. The sorbent preparation techniques developed at IGT have been applied to produce highly reactive and attrition resistant sorbent pellets for moving-bed applications. To minimize attrition losses and achieve optimum packing efficiency, a special pelletization technique was used to produce durable and highly reactive spherical sorbent pellets. In this paper, the results of experiments carried out for the evaluation of the long-term durability and regeneration ability of selected copper chromite pellet formulations are presented and discussed. 97103493 Current techniques in reclamation and treatment of fine coal reject reserves Henry, C. D. et al. Proc. In/. Tech. Conf Coal Util. Fuel Syst., 1995, 20, 583-594. A logical and reasoned evaluation of the resource and treatment methods for the recovery and treatment of fine coal reject from slurry ponds can yield economic operation. When supported by appropriate technologies, the business of fine coal recovery and treatment can compete with traditional coal mining operations in the range of economic conditions experienced by the coal industry. The combination of unique technologies and evaluations allows MDC to compete not only on a value for energy basis, but also provides an added reclamation benefit to the coal industry.
Fuel and Energy Abstracts
September
1997
295
of
anthracites
V. D.
and
production
Ugol’ U/o., 1996, (12)
of
15-19. (In
Benefits of advanced coal cleaning in MCWS 97t934al preparation Itvokumbul. M. T. et al. Proc. Int. Tech. Corrf. Coal Util. Fuel Syst., 1994, 19, 565-5 74. In order to obtain the desired particle size distribution, the coal is pulverized in micronized coal water slurry preparation (MCWS). The need for introducing a precleaning stage prior to the final slurry formulation and the potential advantages and disadvantages of an integrated cleaning/size reduction process are discussed. 97193402 Cireddu, P.
Characteristic
et al.
of coal water slurries
for gasifiers.
Proc. Int. Tech. Conf. Coal Util. Fuel Syst.. 1993. 18, J83-
797.
Studies the preparation of Sulcis (Italy) coal water slurries for gasification by using wet ball mill grinding. Closed-water circuitry of a coal preparation plant 97163403 with jig-flotation process Peizao. S. and Baexin, G. Proc. In/. Tech. Conf. Coal Util. Fuel Syst., 1993.
IX. 60I-606. The paper describes the coal preparation system with its jig circuit treating coal down to submillimetre. It can be operated with closed-water circuit by fully using the function of compressed air in jigging and by mini introduction of under-screen water. Coal beneficiation-sulfur removal using methanol 97193484 Wang, G. and Trass, 0. Proc. In/. Tech. Cortf: Coal Util. Fuel Syrt.. 1997, 22. 5 13-520.
A 300 ml hatch reactor was used to study sulfur removal from coal by methanol. Illinois IBC-108 coal is highly beneficiated and contains mainly organic sulfur: the results can also be applied to organic sulfur removal. Temperature. reaction time and methanol level increased sulfur removal. However. coal level decreased sulfur removal. Coal pyrolysis was explored in both open and closed systems. The best results gave a total sulfur removal of 86% (90% for organic) at 500°C. 60-90 min reaction time and very small amounts of coal, with a weight loss of about 30%. Total sulfur removal is presented in an empirical correlation. Coal characterization and high gradient magnetic 97103485 separation studies of coal fines from Paradise Kentucky Harvey, C. C. et al. Proc. In/. Tech. Conf: Coal Util. Fuel Syst.. 1997, 22, flos-616. Selected samples of five characterized coal slurry ponds at the TVA Paradise facility in Western Kentucky were subjected to high gradient magnetic separation (HGMS) studies. The objective was to determine whether or not HGMS is an effective technique for pyritic sulfur and ash removal from coal fines. Wet HGMS studies were conducted over a range of concentrations, and at different field strengths of up to 2 T (20,000 G). Various matrices were used in the magnet. Grinding to finer particle sizes liberates the pyrite and ash-forming minerals, enhancing their separation in the magnet. At particle sizes greater than 200 mesh clogging occurred within the magnet when the finer wool matrix was used. Tests are currently underway at higher field strengths of 6 T. By a single pass through the magnet the sulfur content of the coal fines was reduced by between 1.5 and 2% while the ash content also reduced by 7%. Additional sulfur removal was possible with second and third passes, but the sulfur reductions were lower. Excessive abundance of ash-forming minerals (above 40%) limited the effectiveness of the magnet. A front end process to remove the majority of the ash-forming minerals and provide a fine feed for the magnet, should enhance the effectiveness of HGMS. Therefore, HGMS may be more effective as a polishing step following more conventional coal cleaning technologies. Coal cleaning: an underutilized solution? 97103466 Godfrey, R. L. Proc. In/. Tech. Conf: Coal Util. Fuel Syst., 1995, 20, 709120.
The author reports the activities of the most advanced facilities of Custom Coals Corporation of Pittsburgh, PA.
coal
cleaning
Coal pond fines cleaning with classifying cyclones, 97103407 spirals, and column flotation Carson, W. R. et al. Proc. In/. Tech. Conf: Coal U/i/. Fuel Syst., 1997, 22, 585-596.
The Illinois Basin is the location of large reserves of coal pond fines which, if used to produce coal-water slurry (CWS), could reduce fuel costs, NO, emissions, and pond closure costs. Coal fines from this region for production of CWS for co-fire or re-burn may require processing to attain proper particle size distribution and fuel quality. To evaluate the effectiveness of using coal cleaning technologies to control these CWS quality parameters, a simple flowsheet for recovering and processing coal pond fines was designed and tested. Coal fines processing comprised classifying cyclones to size at nominal minus 200 mesh, cleaning the classifying cyclone underflow using spirals, and cleaning the overflow using
Solid fuels (preparation)
column froth flotation. Ash content of the clean coal from the spiral was reduced to -lo%, a satisfactory level for CWS co-firing in a cyclone-fired boiler. The clean coal from column flotation may be used for re-burn in a cyclone-fired boiler or as co-fire fuel in a wall-fired or tangentially-fired boiler. Heating value recovery of -80% was achieved during laboratory scale, pilot-scale, and commercial-scale coal cleaning testing. 97103488 Coal slurry dewatering at Mohave Generating Statlon Duey, B. Proc. In/. Tech. Conf. Coal Util. Fuel Syst., 1994, 19, 473-484. The Black Mesa pipeline (275 mi) and coal slurry dewatering at the station are described. 97103489 Coal upgrading in a MagMill Oder, R. R. et al. Proc. In/. Tech. Conf. Coal Util. Fuel Syst., 1996, 21 1317326.
In order to remove non-combustible minerals and to lower the concentration of pollutants, such as sulfur and heavy metals, many coals are wetcleaned at the mine. Due to the high cost of pulverizing, cleaning, dewatering, and shipping fine sized coal, this cleaning is carried out at the coarsest practicable size which consequently limits the effectiveness of wet coal cleaning. This paper reports results of an on-going programme to develop the MagMill, a practical dry coal cleaning technology. It is an innovative method which combines pulverization and magnetic beneficiation in one unit. 97103490 Composition, structure and pyrolysis of cyclohexanone extracts of Yanzhou coal Chen. C. et al. Ranliao Huaxue Xuehno. 1997. 25, (2), 135-138. (In Chinese) A new solvent for coal extraction is presented, called cyclohexanone. The extracts of high extraction yield and high molecular weight are available for investigating the coal molecular structure. Preasphaltenes and asphaltenes are the main components of the extracts The structure analysis by FTIR and lH-NMR showed that preasphaltenes, compared with asphaltenes, had a higher aromaticity (0.12 for preasphaltene and 0.63 for asphaltene) and more bridge methylene but less side alkyl. The pyrolysis reaction of the extracts occurred at 200-600°C and the main pyrolysis product of the extracts was tar. 97103491 Control of hazardous air pollutant precursors by advanced coal preparation Luttrell, G. H. et al. Pollut. Prev. Process Eng., Proc. Tech. Solutions Pollut. Prev. Min. Miner. Process. Ind., Eng. Found. Conf., 1995, (Pub. 1996), I1 l120. Edited by Richardson, P. E. C. and Schemer, B. J., Engineering Foundation, New York, NY. New emission standards for 189 potentially hazardous air pollutants will be established under implementation of the 1990 Clean Air Act Amendment. Several of these, such as arsenic, mercury and selenium, are present as trace elements in run-of-mine coals, Research conducted at Virginia Tech suggests that many of these elements can be efficiently rejected prior to coal combustion using a two-stage physical cleaning circuit that combines advanced froth flotation with an enhanced gravity separator. By combining both units in a single circuit, improved rejections of a wide variety of trace elements can be achieved. This paper describes the findings of recent pilotscale test work conducted to evaluate the capabilities of this novel two-stage circuit for removing trace elements from an Illinois No. 6 coal. 97103492 Copper-based sorbents for hot coal gas desulfurization systems Abbasian, J. et al. Proc. In/. Tech. Conf: Coal Util. Fuel Syst., 1997. 22, 7182.
IGT has developed a copper-chromite sorbent for hot coal gas desulfurization. The results obtained so far indicate that this sorbent, in granular form, has a much higher attrition resistance compared to the commercial granular zinc titanate sorbent, as well as excellent desulfurization efficiency. Furthermore, the reactivity of IGT’s CuCr-29 sorbent gradually and consistently improved during the 20 cycles tested. The sorbent preparation techniques developed at IGT have been applied to produce highly reactive and attrition resistant sorbent pellets for moving-bed applications. To minimize attrition losses and achieve optimum packing efficiency, a special pelletization technique was used to produce durable and highly reactive spherical sorbent pellets. In this paper, the results of experiments carried out for the evaluation of the long-term durability and regeneration ability of selected copper chromite pellet formulations are presented and discussed. 97103493 Current techniques in reclamation and treatment of fine coal reject reserves Henry, C. D. et al. Proc. In/. Tech. Conf Coal Util. Fuel Syst., 1995, 20, 583-594. A logical and reasoned evaluation of the resource and treatment methods for the recovery and treatment of fine coal reject from slurry ponds can yield economic operation. When supported by appropriate technologies, the business of fine coal recovery and treatment can compete with traditional coal mining operations in the range of economic conditions experienced by the coal industry. The combination of unique technologies and evaluations allows MDC to compete not only on a value for energy basis, but also provides an added reclamation benefit to the coal industry.
Fuel and Energy Abstracts
September
1997
295