- Email: [email protected]
00446 The effect of blending coals on char morphology, intrinsic reactivity and volatile release
06
Electrical power supply and utilization (scientific, technical)
to the proposition of inductive impedances and a commutative capacitive for the ring part of the studied system, where this condition is taken into consideration. This work and the results herein are a great development and a good imorovement on the oerformance of the ring transmission system.-Also, thk effect of place of cbnnection of the proposed ring bank is investigated for different locations along the line. The effect of load power factor on the distribution of node voltages and branch currents as weli as on both active and reactive powers along the proposed new bank ring system have been worked out and analysed.
The effect of blending coals on char morphology, lntrlnslc reactivity and volatile release
in a carbonate fuel cell. This paper describes the second option. The gasification study includes both experimental testing in a pilot-scale gasifier and computer simulation of carbonate fuel cell performance when operated on gas derived from switchgrass. Options for a comprehensive system integration between a carbonate fuel cell and the gasification system are being evaluated. Use of waste heat from the carbonate fuel cell to maximize overall integrated plant efficiency is being examined. Existing fuel cell power plant design elements will be used, as appropriate, in the integration of the gasifier and fuel cell power plant to minimize cost complexity and risk.
99100446
Lester, E. et al. IChemE Res. Event, Two-Day Symp., 1998, 621-628. In pulverized fuel-injected power stations an initial investigation was carried out for the use of coal blends. A 106-180 1~fraction of a low-rank Indonesian coal (Kaltim Prima) was blended with iive different world coals in the ratio 75%:25% (wtiwt), respectively. These blends were then fired through a drop tube furnace to produce pyrolyzed semicoke samples. Novel image analysis techniques were used to quantify various petrographical features in the coals and moruholoev features in the semicokes. Even in the drop tube furnace, coals ma; not necessarily behave independently when blended with other coals. In terms of intrinsic reactivity, volatiles release and semicoke morphology, blended semi-cokes in the drop tube furnace appear to behave as the least reactive component.
Effect of Inhibitors on Zn-dendrite formation for zinc-polyanlllne secondary battery
99100447
Kan, J. et al. Journal of Power Sources, 19982+74, (l), 113-116. sodium lauryl sulfate and In Zn-polyaniline batteries the effects of Pb Triton X-100 on inhibition of Zn-dendrite growih were studied by scanning electron micrograph and cyclic voltammetry. The results show that Triton X-100 in the region of 0.02-500 ppm in the electrolyte containing 2.5 M ZnClz and 2.0 M NH&I with pH 4.40 can effectively inhibit zinc-dendrite growth during charge-discharge cycles of the battery and yield longer cycles.
Effects of surface treatment on performances of metal hvdride electrodes and Ni/MH batteries
99100446
Chen, W:et al. Journal of Power Sources, 1998, 74, (l), 34-39. To increase the discharge capacity and high-rate dischargeability and to improve the activation, metal hydride (MR) electrodes are treated in an alkaline solution containing potassium borohydride (KBH4), electrocatalytic activity and cyclic stability. XPS and ICP analyses indicate that the nickel oxide on the surface of the hydrogen-storage alloy is partly reduced by the reduction treatment. Part of the atomic hydrogen released during this treatment is adsorbed on the surface of the alloy and penetrates into the lattice to form the hydride. It is found that a Ni-rich surface layer with a high electrocatalytic activity for the electrode reaction is produced because of the preferential dissolution of Mn and Al. In addition, the specific surface area of the treated alloy is increased.
Electrocatalytic activity of spinel-type oxides LlMn2_,Co,0a with large surface areas for metal-air . _ specific battery
99100449
Li, N. et al. Journal of Power Sources, 1998, 74, (Z), 255-258. Using an improved amorphous citric precursor (ACP) method a series of spinel-type oxides LiMn2,Co,04 (x = 1.0, 1.2, 1.4, 1.6) are synthesized. Their specific surface areas are measured by the Brunauer-Emmet-Teller (BET) method, and their particle agglomerates are studied by scanning electron microscopy (SEM). Their electrocatalytic performances are characterized by the polarization curves of gas-diffusion electrodes that employ the oxides. The activity decreases with increasing X values. 99l00450
Estimation
of thermal
efficiency
for
IG-MCFC
system Nakayama, T. et al. Nippon Enerugi Gakkaishi, 1998, 77, (4), 331-340. (In Japanese) IG-MCFC (integrated coal gasification-molten carbonate fuel cell) power generation plant efficiency is higher than that of IGCC (integrated coal gasification combined-cvcle). An IG-MCFC power veneration olant efficiency was established that combines 02 blown-type or air blownltype gasifier and a wet gas purification unit. First, wet gas purification systems were surveyed in point of motive power and utility. Three types of wet gas sulfur-absorbing processes (MDEA, Selexsol and DEA process) were investigated. The MDEA process was recognized as most hopeful among proposed wet gas sulfur absorbing processes. The thermal efficiency of the IG-MCFC power generation plant was studied using software developed by CRIEPI in 1994. In conclusion, the net thermal efficiency of the system was about 50%.
Evaluation of an Integrated biomass gaslflcatlon 99lQO451 fuel cell power plant Smeenk, J. et al. Making Bus. Biomass Energy, Environ., Chemical, Fibers Mater., Proc. Biomass Conf. Am. 3rd, 1997, (2), 1353-1361. Edited by Overend. R. P. and Chornet. E. The goal of the Chariton Valley Biomass Power Project, sponsored by the US Department of Energy Biomass Power Program, is to convert switchgrass grown on marginal-farmland in southern-Iowa into electric power. Two energy conversion options are under evaluation: cofiring switchgrass with coal in an existing utility boiler and gasification of switchgrass for use
44
Fuel and Energy Abstracts
January 1999
Experimental pulverizer model
99l90452
Murty, G. V. R. er al.
flow
lnvestlgatlons
PWR (Am. Sot. Mechanical
Eng.),
In 1996,30,
a
coal
(2), 915-
924.
In India, the operational experience of their 200 MW/500 MW thermal power plants in indicates that the service life of components of the Raymond bowl mills (rolls, bull ring segments, etc.) which supply pulverized coal to boilers is much less than expected. The faster wear is due to stress assisted abrasion caused by highly abrasive ash in the Indian coals. The improper distribution of primary air in the mill can lead to the retention of a-quartz in the mill and cause abrasion. For this it was found necessary to study the flow distribution by carrying out measurements with a five hole probe within the mill. These studies on a scaled down model of the mill revealed that, for the existing designs, the flow was not amenable for measurement and led to the study using flow visualization with coloured particles. The results indicated the presence of low flow regions as well as regions of flow reversal. A set of modifications grouped under four categories have been made and the flow field was measured and analysed.
Final results for the EPRI-DOE-SCS Chiyoda thoroughbred CT-121 clean coal project at Georgla power’s plant Yates
99lQO453
Burford,
D. P.
Proc. Annu.
Inr. Pittsburgh Coal Conf.,
1997, 14, (27), 28-
52.
In order to treat hot flue gases of a coal-fired, 110 MW electric utility boiler, the Yates Clean Coal Project was set up, a co-funded Clean Coal Technology effort evaluating a retrofit wet limestone-based, SO2 scrubbing system. This project tested the operational limits of Chiyoda’s CT-121 Jet Bubbling Reactor System at Georgia Power’s Plant Yates from 1992 through 1994. Although the original test plan called for a very conservative assessment, the CT-121 system proved robust, so it was tested at widely varying conditions. Fuel sulfur content was 1.5-4.3%, various limestone sources at several grind sizes were used, particulate removal and air toxics performance were measured and by-product gypsum soil amendment experimentation was conducted. In all cases, the CT-121 system gave encouraging results with predictably high SO2 (95-99%) and particulate removals (99+%) at all conditions with high reliability. Closed loop operations which called for extensive application of corrosion impervious, fibreglass reinforced plastics was also very successful.
99100454
Fuel cell
power
plants
uslng
hydrogen
from
biomass Knight, R. A. et al. Proc. Am. Power Conf., 1998, 60, (l), 586-591. A power generation system that offers high energy efficiency, near-zero greenhouse gas emissions and ultra-clean environmental performance is discussed in this paper. Biomass from agricultural and forestry wastes or dedicated energy farms can be used efficiently for power generation in integrated biomass gasification-fuel cell (IBGFC) systems. The energy efficiency of these systems has been projected to approach 55% or even higher if cogeneration opportunities can be utilized. Such systems, in addition to being ultra-efficient, can boast very low emissions of SO*, NO,, and particulates, and are essentially CO*-neutral. With the mounting concern about greenhouse gas emissions, this approach to renewable energy is very attractive for small distributed generation markets in the USA and worldwide. Biomass wastes alone, by current estimates, have the potential to provide as much as 338 GW of electric power worldwide if utilized in this fas’hion, and offer the best near-to midteim market entry opportunities for this technology. In this paper, the integration of a pressurized fluidized bed gasifier with a molten carbonate fuel cell and expansion turbine bottoming cycle will be presented. Two cycles are suggested: one using conventional technology for biomass drying, feeding, and gasification, and a second, more advanced cycle using wet feeding direct to the gasifier and in-bed steam reforming to boost cycle efficiency and reduce capital costs. Both cycles use state-of-the-art molten carbonate fuel cells with an expansion turbine bottoming cycle.
Fuuy control In power stations. Potentials and possible applications
99lO9455
Gierend, C. VGB Krafiwerkstech., 1998, 78, (5), 118-125. (In German) Presented is a review on the application potentials of fuzzy logic in waste incineration processes including the control of the fueling rate, grate speed, and distribution of combustion air. The fuzzy control is suitable to optimize fluctuating qualities of refuse, to minimize pollutants, and to achieve maximum economic loading of the plant.
Electrical power supply and utilization (scientific, technical)
to the proposition of inductive impedances and a commutative capacitive for the ring part of the studied system, where this condition is taken into consideration. This work and the results herein are a great development and a good imorovement on the oerformance of the ring transmission system.-Also, thk effect of place of cbnnection of the proposed ring bank is investigated for different locations along the line. The effect of load power factor on the distribution of node voltages and branch currents as weli as on both active and reactive powers along the proposed new bank ring system have been worked out and analysed.
The effect of blending coals on char morphology, lntrlnslc reactivity and volatile release
in a carbonate fuel cell. This paper describes the second option. The gasification study includes both experimental testing in a pilot-scale gasifier and computer simulation of carbonate fuel cell performance when operated on gas derived from switchgrass. Options for a comprehensive system integration between a carbonate fuel cell and the gasification system are being evaluated. Use of waste heat from the carbonate fuel cell to maximize overall integrated plant efficiency is being examined. Existing fuel cell power plant design elements will be used, as appropriate, in the integration of the gasifier and fuel cell power plant to minimize cost complexity and risk.
99100446
Lester, E. et al. IChemE Res. Event, Two-Day Symp., 1998, 621-628. In pulverized fuel-injected power stations an initial investigation was carried out for the use of coal blends. A 106-180 1~fraction of a low-rank Indonesian coal (Kaltim Prima) was blended with iive different world coals in the ratio 75%:25% (wtiwt), respectively. These blends were then fired through a drop tube furnace to produce pyrolyzed semicoke samples. Novel image analysis techniques were used to quantify various petrographical features in the coals and moruholoev features in the semicokes. Even in the drop tube furnace, coals ma; not necessarily behave independently when blended with other coals. In terms of intrinsic reactivity, volatiles release and semicoke morphology, blended semi-cokes in the drop tube furnace appear to behave as the least reactive component.
Effect of Inhibitors on Zn-dendrite formation for zinc-polyanlllne secondary battery
99100447
Kan, J. et al. Journal of Power Sources, 19982+74, (l), 113-116. sodium lauryl sulfate and In Zn-polyaniline batteries the effects of Pb Triton X-100 on inhibition of Zn-dendrite growih were studied by scanning electron micrograph and cyclic voltammetry. The results show that Triton X-100 in the region of 0.02-500 ppm in the electrolyte containing 2.5 M ZnClz and 2.0 M NH&I with pH 4.40 can effectively inhibit zinc-dendrite growth during charge-discharge cycles of the battery and yield longer cycles.
Effects of surface treatment on performances of metal hvdride electrodes and Ni/MH batteries
99100446
Chen, W:et al. Journal of Power Sources, 1998, 74, (l), 34-39. To increase the discharge capacity and high-rate dischargeability and to improve the activation, metal hydride (MR) electrodes are treated in an alkaline solution containing potassium borohydride (KBH4), electrocatalytic activity and cyclic stability. XPS and ICP analyses indicate that the nickel oxide on the surface of the hydrogen-storage alloy is partly reduced by the reduction treatment. Part of the atomic hydrogen released during this treatment is adsorbed on the surface of the alloy and penetrates into the lattice to form the hydride. It is found that a Ni-rich surface layer with a high electrocatalytic activity for the electrode reaction is produced because of the preferential dissolution of Mn and Al. In addition, the specific surface area of the treated alloy is increased.
Electrocatalytic activity of spinel-type oxides LlMn2_,Co,0a with large surface areas for metal-air . _ specific battery
99100449
Li, N. et al. Journal of Power Sources, 1998, 74, (Z), 255-258. Using an improved amorphous citric precursor (ACP) method a series of spinel-type oxides LiMn2,Co,04 (x = 1.0, 1.2, 1.4, 1.6) are synthesized. Their specific surface areas are measured by the Brunauer-Emmet-Teller (BET) method, and their particle agglomerates are studied by scanning electron microscopy (SEM). Their electrocatalytic performances are characterized by the polarization curves of gas-diffusion electrodes that employ the oxides. The activity decreases with increasing X values. 99l00450
Estimation
of thermal
efficiency
for
IG-MCFC
system Nakayama, T. et al. Nippon Enerugi Gakkaishi, 1998, 77, (4), 331-340. (In Japanese) IG-MCFC (integrated coal gasification-molten carbonate fuel cell) power generation plant efficiency is higher than that of IGCC (integrated coal gasification combined-cvcle). An IG-MCFC power veneration olant efficiency was established that combines 02 blown-type or air blownltype gasifier and a wet gas purification unit. First, wet gas purification systems were surveyed in point of motive power and utility. Three types of wet gas sulfur-absorbing processes (MDEA, Selexsol and DEA process) were investigated. The MDEA process was recognized as most hopeful among proposed wet gas sulfur absorbing processes. The thermal efficiency of the IG-MCFC power generation plant was studied using software developed by CRIEPI in 1994. In conclusion, the net thermal efficiency of the system was about 50%.
Evaluation of an Integrated biomass gaslflcatlon 99lQO451 fuel cell power plant Smeenk, J. et al. Making Bus. Biomass Energy, Environ., Chemical, Fibers Mater., Proc. Biomass Conf. Am. 3rd, 1997, (2), 1353-1361. Edited by Overend. R. P. and Chornet. E. The goal of the Chariton Valley Biomass Power Project, sponsored by the US Department of Energy Biomass Power Program, is to convert switchgrass grown on marginal-farmland in southern-Iowa into electric power. Two energy conversion options are under evaluation: cofiring switchgrass with coal in an existing utility boiler and gasification of switchgrass for use
44
Fuel and Energy Abstracts
January 1999
Experimental pulverizer model
99l90452
Murty, G. V. R. er al.
flow
lnvestlgatlons
PWR (Am. Sot. Mechanical
Eng.),
In 1996,30,
a
coal
(2), 915-
924.
In India, the operational experience of their 200 MW/500 MW thermal power plants in indicates that the service life of components of the Raymond bowl mills (rolls, bull ring segments, etc.) which supply pulverized coal to boilers is much less than expected. The faster wear is due to stress assisted abrasion caused by highly abrasive ash in the Indian coals. The improper distribution of primary air in the mill can lead to the retention of a-quartz in the mill and cause abrasion. For this it was found necessary to study the flow distribution by carrying out measurements with a five hole probe within the mill. These studies on a scaled down model of the mill revealed that, for the existing designs, the flow was not amenable for measurement and led to the study using flow visualization with coloured particles. The results indicated the presence of low flow regions as well as regions of flow reversal. A set of modifications grouped under four categories have been made and the flow field was measured and analysed.
Final results for the EPRI-DOE-SCS Chiyoda thoroughbred CT-121 clean coal project at Georgla power’s plant Yates
99lQO453
Burford,
D. P.
Proc. Annu.
Inr. Pittsburgh Coal Conf.,
1997, 14, (27), 28-
52.
In order to treat hot flue gases of a coal-fired, 110 MW electric utility boiler, the Yates Clean Coal Project was set up, a co-funded Clean Coal Technology effort evaluating a retrofit wet limestone-based, SO2 scrubbing system. This project tested the operational limits of Chiyoda’s CT-121 Jet Bubbling Reactor System at Georgia Power’s Plant Yates from 1992 through 1994. Although the original test plan called for a very conservative assessment, the CT-121 system proved robust, so it was tested at widely varying conditions. Fuel sulfur content was 1.5-4.3%, various limestone sources at several grind sizes were used, particulate removal and air toxics performance were measured and by-product gypsum soil amendment experimentation was conducted. In all cases, the CT-121 system gave encouraging results with predictably high SO2 (95-99%) and particulate removals (99+%) at all conditions with high reliability. Closed loop operations which called for extensive application of corrosion impervious, fibreglass reinforced plastics was also very successful.
99100454
Fuel cell
power
plants
uslng
hydrogen
from
biomass Knight, R. A. et al. Proc. Am. Power Conf., 1998, 60, (l), 586-591. A power generation system that offers high energy efficiency, near-zero greenhouse gas emissions and ultra-clean environmental performance is discussed in this paper. Biomass from agricultural and forestry wastes or dedicated energy farms can be used efficiently for power generation in integrated biomass gasification-fuel cell (IBGFC) systems. The energy efficiency of these systems has been projected to approach 55% or even higher if cogeneration opportunities can be utilized. Such systems, in addition to being ultra-efficient, can boast very low emissions of SO*, NO,, and particulates, and are essentially CO*-neutral. With the mounting concern about greenhouse gas emissions, this approach to renewable energy is very attractive for small distributed generation markets in the USA and worldwide. Biomass wastes alone, by current estimates, have the potential to provide as much as 338 GW of electric power worldwide if utilized in this fas’hion, and offer the best near-to midteim market entry opportunities for this technology. In this paper, the integration of a pressurized fluidized bed gasifier with a molten carbonate fuel cell and expansion turbine bottoming cycle will be presented. Two cycles are suggested: one using conventional technology for biomass drying, feeding, and gasification, and a second, more advanced cycle using wet feeding direct to the gasifier and in-bed steam reforming to boost cycle efficiency and reduce capital costs. Both cycles use state-of-the-art molten carbonate fuel cells with an expansion turbine bottoming cycle.
Fuuy control In power stations. Potentials and possible applications
99lO9455
Gierend, C. VGB Krafiwerkstech., 1998, 78, (5), 118-125. (In German) Presented is a review on the application potentials of fuzzy logic in waste incineration processes including the control of the fueling rate, grate speed, and distribution of combustion air. The fuzzy control is suitable to optimize fluctuating qualities of refuse, to minimize pollutants, and to achieve maximum economic loading of the plant.