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Effects of organic acid pretreatment on the structure and pyrolysis reactivity of coals
01 Solid fuels (preparation) The charging process consists of moving a hopper vehicle to the charging position, charging coal (e.g. with belt feeder or screw feeder), then waste plastics, and finally covering with coal, and moving to the coke oven.
02/00753 Chemical treatment of coal by grinding and aqueous caustic leaching Bal~z, P. et ,l. Fuel, 2001, 80, (5), 665-671. The aim of this work has been to point out the possibility of using GACL process for chemical cleaning of brown coal Nov~ky (Slovakia) and Pittsburgh No. 8 coal. Simultaneous grinding and aqueous chemical leaching, which is the principle of the process, reduces the inorganic and inorganic sulfur content in both coals. Dearsenification nearly up to 96% is detected in GACL-treated samples of Nov~ky coal. The possibility of enhancing the recovery of humic acid as a consequence of GACL treatment is demonstrated. The process under study works under atmospheric pressure, temperature of 90°C and NaOH consumption, which is six times lower compared with the MCL process. Further research is needed to minimize the wear of grinding media and to improve the washing step.
02/00754 Desulfurization of coal for decreasing sulfur emissions Somerville, R.B. and Fan, L-T. PCT Int. Appl. WO 01 25,373 (CI. C10L9/10), 12 Apr 2001, US Appl. PV157,657, 5 Oct 1999. 12. A method of manufacturing a coal product having reduced sulfur emissions includes the steps of (1) grinding coal into a powder form having a desired particle size, (2) blending the ground coal with hydrated lime, (3) adding water to the blend to have a moisture content of 10-30 wt%, and (4) drying the water-added blend to have a desired reduced moisture content. The desired reduced moisture content is < 1% of the total weight of the coal powder and the hydrated lime. The drying step includes heating the water-added blend to a temperature of 300-400°F in an externally heated furnace. Waste heat from a power plant can be used to heat the blend.
The results of epidemiology studies in various countries show that radon and its progeny cause carcinogenic effects in mine workers. Therefore, it becomes of paramount importance to monitor radon concentrations and consequently determine the radon dose rates in coal mines for the protection of coal miners. A new calibration curve was obtained for radon concentration estimation using hybrid techniques. A calibration curve was generated using the 226Ra activity concentration measured by a HPGe detector-based gamma-ray spectrometer vs. the a-track-density rate due to radon and its progeny on a CR-39 track detector. Using the slope of the experimental determined curve in the units of Bq/kg [~er unit ~-track-densitv per h (cm 2 h 1), radon concentrations (Bq/m-) were established using coal samples from various coal mines in two provinces of Pakistan, Punjab and Baluchistan. Radon dose rates were computed in the simulated environment of the coal mines. The results of these computations may be considered with a caveat that the method developed in this paper provides only a screening method to indicate the radon dose in coal mines. It has been shown that the actual measurements of radon concentrations in the coal mines are in agreement with the established radon concentrations using the hybrid-technique calibration curve.
02/00759 Fundamentals for separation of particles mixture of two components. Belokryletskii, A.V. and Belokryletskii, V.I. Izv. Vyssh. Uchehn. Zaved., Gorn. Zh., 2000, 6, 105 111. (In Russian) A mathematical model is developed for the calculations of concentration of coal in a pneumatic separator in which the separation and formation of products are independent processes and their determining parameters are different. The separation of coal by density is determined by the quality of initial material, efficiency, inclination angle of deck, and frequency of vibration. The formation of concentrated product is performed by the variation of location of separating blade.
02/00760 Internal gas pressure characteristics generated during coal carbonization in a coke oven
Malysa, E. Gospod. Surowcarni Miner., 2000, 16, (1), 29~41. (In Polish) Coal flotation depends on various parameters and grain size is one of the important factors. The larger the grain size, the higher is the probability of its collision with air bubble and formation of the bubblegrain aggregate. Stability of the bubble-grain aggregate depends on the magnitude of the forces tending to destroy the aggregate and is a function of the grain density and size. The results of influence of the grain size on process of coal flotation are presented. To get rid of the effect of density the grain classes floated were chosen in such a manner that they had very similar densities, but different sizes. A clear difference was observed in flotation results of the grain classes having the same densit~ and different sizes. In the case of grains with density below 1.4 Mg/m ~ their floatability increased with increasing size of the grains. However, for grains of density higher than 1.4 Mg/m 3 the floatability was decreasing with increasing size of the grains.
Lee, W-J. and Lee, Y-K. Energy F,wls, 2001, 15, (3). 618-623. Coal carbonization for various kinds of single coals, coal blends, and operating conditions was carried out in a movable-wall test coke oven (0.18 mW x 0.4 mH x 0.45 ml) to investigate the coking pressure behaviour. The internal gas pressure and its corresponding temperature at the coal charge centre were measured using the probe with thermocouple. Internal gas pressure of single coals increases with an increase of coking capacity and a decrease of volatile matter content. The internal gas pressure and the coke strength of coal blends mixed with single coals mainly depend on the blending ratio of a given coal in coal blends. With decreasing moisture content of coal blends, heating rate at the coal charge centre decreases and internal gas pressure exponentially increases. Bulk density of coal blends increases exponentially with decreasing moisture content. Also, coke strength linearly increases with a decrease of coal moisture content. With increasing heating-wall temperature, internal gas pressure of coal blends increases, but coke strength decreases.
02/00756 Effects of organic acid pretreatment on the structure and pyrolysis reactivity of coals
02/00761 Method for estimation of moisture content in coals using regression model
Sakanishi, K. et al. Fuel, 2001, 80, (2), 273-281. Mild acid pretreatment was performed using aqueous acetic acid or methoxyethoxy acetic acid to remove bridging cations through oxygen functional groups and to improve the pyrolytic reactivity of three coals (Beulah-Zap, BZ; Wyodak, WY; Illinois #'6, IL)..The acid pretreatment removed ion-exchangeable cations such as Ca and Mg from lower ranking coals, and enhanced their swelling by pyridine, and increased their volatile yield in the flash pyrolysis. The CO/CO2 ratio produced in the flash pyrolysis from lower rank coals increased by the acid treatment. The pretreatment liberates the cation-bridging network through the oxygen functional groups of coal. The acid treatment converts the carboxylates into their free carboxylic acids, enhancing the thermal decomposition into smaller hydrocarbons and their devolatilization through the pores. Acid treatment appears to loosen the 7r-re stacking and intensify the alkyl entanglement. The slow step scan XRD confirms the influences of such treatments on the lower rank coals.
Kaihara, M. Jpn. Kokai Tokkyo Koho JP 2001 116,689 (CI. G01N21/ 35), 27 Apr 2001, Appl. 1999/294,419, 15 Oct 1999.5. (In Japanese) Moisture content in coals is estimated by measuring near-IR spectrum and then using regression model. The method provides rapid analysis and is especially suitable for online process control.
02/00755
02/00757
Effect of grain size on results of coal flotation
Equipment for granulation of coal dust
Shevchenko, N.Ya. and Pekur, V.Z. Ugol' Ukr., 2000, 10, 37. (In Russian) A technological scheme is presented for preparation and granulation of coal dust-argillite mixture. The technical characteristics of press granulator are given. The technology for granulation of coal dust from coal plants by using ecologically pure binder and press granulator enables the production of coal dust with good desirable properties.
02/00758 Estimation of radon concentrations in coal mines using a hybrid technique calibration curve Jamil, K. and All, S. J. Environ. Radioact, 2001, 54, (3), 415-422.
02/00762 Method for pre-treatment of coal for coke manufacture with control of tar adding ratio Yamaguchi, A. et al. Jpn. Kokai Tokkyo Koho JP 2001 72,982 (CI CIOB57/08), 21 Mar 2001, Appl. 1999/'249,268, 2 Sep 1999. 10. (In Japanese) The method is carried out by predicting the particle-size distribution of dried coal (different brand) before classification, predicting ratio of dust-causing fine particles contained in the coal particle from the prevented distribution and its corresponding classification point, then adjusting the classification point to increase the classification rate for decrease of dust-causing fine particle ratio with limit of pre-set tar adding ratio.
02/00763 Modification of raw gas composition during coking in wide chambers Arendt, P. et al. GlueckaufFor.~'chungsh, 2001 62, (1), [5-16. 18--19 (In German) The renovation of the Prosper coke works was completed in 1989. The main purpose of this project, which involved 150 large-capacity ovens grouped into three coking batteries, was to increase the oven chamber width to 600 mm (cold state dimensions). Surprisingly, these a h e r a tions produced a marked change in the quality and quantity of the coke-oven gas and coal byproducts. The gas exhibited a lower density
Fuel and Energy Abstracts
March 2002
93
02/00753 Chemical treatment of coal by grinding and aqueous caustic leaching Bal~z, P. et ,l. Fuel, 2001, 80, (5), 665-671. The aim of this work has been to point out the possibility of using GACL process for chemical cleaning of brown coal Nov~ky (Slovakia) and Pittsburgh No. 8 coal. Simultaneous grinding and aqueous chemical leaching, which is the principle of the process, reduces the inorganic and inorganic sulfur content in both coals. Dearsenification nearly up to 96% is detected in GACL-treated samples of Nov~ky coal. The possibility of enhancing the recovery of humic acid as a consequence of GACL treatment is demonstrated. The process under study works under atmospheric pressure, temperature of 90°C and NaOH consumption, which is six times lower compared with the MCL process. Further research is needed to minimize the wear of grinding media and to improve the washing step.
02/00754 Desulfurization of coal for decreasing sulfur emissions Somerville, R.B. and Fan, L-T. PCT Int. Appl. WO 01 25,373 (CI. C10L9/10), 12 Apr 2001, US Appl. PV157,657, 5 Oct 1999. 12. A method of manufacturing a coal product having reduced sulfur emissions includes the steps of (1) grinding coal into a powder form having a desired particle size, (2) blending the ground coal with hydrated lime, (3) adding water to the blend to have a moisture content of 10-30 wt%, and (4) drying the water-added blend to have a desired reduced moisture content. The desired reduced moisture content is < 1% of the total weight of the coal powder and the hydrated lime. The drying step includes heating the water-added blend to a temperature of 300-400°F in an externally heated furnace. Waste heat from a power plant can be used to heat the blend.
The results of epidemiology studies in various countries show that radon and its progeny cause carcinogenic effects in mine workers. Therefore, it becomes of paramount importance to monitor radon concentrations and consequently determine the radon dose rates in coal mines for the protection of coal miners. A new calibration curve was obtained for radon concentration estimation using hybrid techniques. A calibration curve was generated using the 226Ra activity concentration measured by a HPGe detector-based gamma-ray spectrometer vs. the a-track-density rate due to radon and its progeny on a CR-39 track detector. Using the slope of the experimental determined curve in the units of Bq/kg [~er unit ~-track-densitv per h (cm 2 h 1), radon concentrations (Bq/m-) were established using coal samples from various coal mines in two provinces of Pakistan, Punjab and Baluchistan. Radon dose rates were computed in the simulated environment of the coal mines. The results of these computations may be considered with a caveat that the method developed in this paper provides only a screening method to indicate the radon dose in coal mines. It has been shown that the actual measurements of radon concentrations in the coal mines are in agreement with the established radon concentrations using the hybrid-technique calibration curve.
02/00759 Fundamentals for separation of particles mixture of two components. Belokryletskii, A.V. and Belokryletskii, V.I. Izv. Vyssh. Uchehn. Zaved., Gorn. Zh., 2000, 6, 105 111. (In Russian) A mathematical model is developed for the calculations of concentration of coal in a pneumatic separator in which the separation and formation of products are independent processes and their determining parameters are different. The separation of coal by density is determined by the quality of initial material, efficiency, inclination angle of deck, and frequency of vibration. The formation of concentrated product is performed by the variation of location of separating blade.
02/00760 Internal gas pressure characteristics generated during coal carbonization in a coke oven
Malysa, E. Gospod. Surowcarni Miner., 2000, 16, (1), 29~41. (In Polish) Coal flotation depends on various parameters and grain size is one of the important factors. The larger the grain size, the higher is the probability of its collision with air bubble and formation of the bubblegrain aggregate. Stability of the bubble-grain aggregate depends on the magnitude of the forces tending to destroy the aggregate and is a function of the grain density and size. The results of influence of the grain size on process of coal flotation are presented. To get rid of the effect of density the grain classes floated were chosen in such a manner that they had very similar densities, but different sizes. A clear difference was observed in flotation results of the grain classes having the same densit~ and different sizes. In the case of grains with density below 1.4 Mg/m ~ their floatability increased with increasing size of the grains. However, for grains of density higher than 1.4 Mg/m 3 the floatability was decreasing with increasing size of the grains.
Lee, W-J. and Lee, Y-K. Energy F,wls, 2001, 15, (3). 618-623. Coal carbonization for various kinds of single coals, coal blends, and operating conditions was carried out in a movable-wall test coke oven (0.18 mW x 0.4 mH x 0.45 ml) to investigate the coking pressure behaviour. The internal gas pressure and its corresponding temperature at the coal charge centre were measured using the probe with thermocouple. Internal gas pressure of single coals increases with an increase of coking capacity and a decrease of volatile matter content. The internal gas pressure and the coke strength of coal blends mixed with single coals mainly depend on the blending ratio of a given coal in coal blends. With decreasing moisture content of coal blends, heating rate at the coal charge centre decreases and internal gas pressure exponentially increases. Bulk density of coal blends increases exponentially with decreasing moisture content. Also, coke strength linearly increases with a decrease of coal moisture content. With increasing heating-wall temperature, internal gas pressure of coal blends increases, but coke strength decreases.
02/00756 Effects of organic acid pretreatment on the structure and pyrolysis reactivity of coals
02/00761 Method for estimation of moisture content in coals using regression model
Sakanishi, K. et al. Fuel, 2001, 80, (2), 273-281. Mild acid pretreatment was performed using aqueous acetic acid or methoxyethoxy acetic acid to remove bridging cations through oxygen functional groups and to improve the pyrolytic reactivity of three coals (Beulah-Zap, BZ; Wyodak, WY; Illinois #'6, IL)..The acid pretreatment removed ion-exchangeable cations such as Ca and Mg from lower ranking coals, and enhanced their swelling by pyridine, and increased their volatile yield in the flash pyrolysis. The CO/CO2 ratio produced in the flash pyrolysis from lower rank coals increased by the acid treatment. The pretreatment liberates the cation-bridging network through the oxygen functional groups of coal. The acid treatment converts the carboxylates into their free carboxylic acids, enhancing the thermal decomposition into smaller hydrocarbons and their devolatilization through the pores. Acid treatment appears to loosen the 7r-re stacking and intensify the alkyl entanglement. The slow step scan XRD confirms the influences of such treatments on the lower rank coals.
Kaihara, M. Jpn. Kokai Tokkyo Koho JP 2001 116,689 (CI. G01N21/ 35), 27 Apr 2001, Appl. 1999/294,419, 15 Oct 1999.5. (In Japanese) Moisture content in coals is estimated by measuring near-IR spectrum and then using regression model. The method provides rapid analysis and is especially suitable for online process control.
02/00755
02/00757
Effect of grain size on results of coal flotation
Equipment for granulation of coal dust
Shevchenko, N.Ya. and Pekur, V.Z. Ugol' Ukr., 2000, 10, 37. (In Russian) A technological scheme is presented for preparation and granulation of coal dust-argillite mixture. The technical characteristics of press granulator are given. The technology for granulation of coal dust from coal plants by using ecologically pure binder and press granulator enables the production of coal dust with good desirable properties.
02/00758 Estimation of radon concentrations in coal mines using a hybrid technique calibration curve Jamil, K. and All, S. J. Environ. Radioact, 2001, 54, (3), 415-422.
02/00762 Method for pre-treatment of coal for coke manufacture with control of tar adding ratio Yamaguchi, A. et al. Jpn. Kokai Tokkyo Koho JP 2001 72,982 (CI CIOB57/08), 21 Mar 2001, Appl. 1999/'249,268, 2 Sep 1999. 10. (In Japanese) The method is carried out by predicting the particle-size distribution of dried coal (different brand) before classification, predicting ratio of dust-causing fine particles contained in the coal particle from the prevented distribution and its corresponding classification point, then adjusting the classification point to increase the classification rate for decrease of dust-causing fine particle ratio with limit of pre-set tar adding ratio.
02/00763 Modification of raw gas composition during coking in wide chambers Arendt, P. et al. GlueckaufFor.~'chungsh, 2001 62, (1), [5-16. 18--19 (In German) The renovation of the Prosper coke works was completed in 1989. The main purpose of this project, which involved 150 large-capacity ovens grouped into three coking batteries, was to increase the oven chamber width to 600 mm (cold state dimensions). Surprisingly, these a h e r a tions produced a marked change in the quality and quantity of the coke-oven gas and coal byproducts. The gas exhibited a lower density
Fuel and Energy Abstracts
March 2002
93