The solar thermal gasification of coal -: energy conversion efficiency and CO2 mitigation potential

被引:67
作者
Von Zedtwitz, P
Steinfeld, A [1 ]
机构
[1] ETH Zentrum, ETH Swiss Fed Inst Technol, Dept Mech & Proc Engn, CH-8092 Zurich, Switzerland
[2] Paul Scherrer Inst, CH-5232 Villigen, Switzerland
关键词
D O I
10.1016/S0360-5442(02)00139-1
中图分类号
O414.1 [热力学];
学科分类号
摘要
The steam-gasification of coal (peat, lignite, bituminous, and anthracite) into syngas is investigated using concentrated solar energy as the source of high-temperature process heat. The advantages of the solar-driven process are threefold: (1) the discharge of pollutants is avoided; (2) the gaseous products are not contaminated by combustion byproducts; and (3) the calorific value of the fuel is upgraded. A second-law analysis is carried out for a blackbody solar cavity-receiver/reactor operated at 1350 K and subjected to a mean solar flux concentration ratio of 2000. Two technically viable routes for generating electricity using the gasification products are examined: (1) syngas is used to fuel a 55%-efficient combined Brayton-Rankine cycle; and (2) syngas is further processed to H-2 (by water-gas shift reaction followed by H-2/CO2 separation) which is used to fuel a 65%-efficient fuel cell. The maximum exergy efficiency, defined as the ratio of electric power output to the thermal power input (solar power+heating value of reactants), reaches 50% for the combined cycle route and 46% for the fuel cell route. Both of these routes offer a net gain in the electrical output by a factor varying in the range 1.7-1.9, depending on the coal type and the power generation route, vis-a-vis the direct use of coal for fueling a 35%-efficient Rankine cycle. Specific CO2 emissions amounts to 0.49-0.56 kg CO2/kWh(e), about half as much as the specific emissions discharged by conventional coal-fired power plants. Solar/coal hybrid processes, such as the one examined in this paper, offer important intermediate solutions towards a sustainable energy supply system. (C) 2003 Elsevier Science Ltd. All rights reserved.
引用
收藏
页码:441 / 456
页数:16
相关论文
共 21 条
[1]  
[Anonymous], 1996, OKOINVENTARE ENERGIE
[2]   HIGH-TEMPERATURE SOLAR PYROLYSIS OF COAL [J].
BEATTIE, WH ;
BERJOAN, R ;
COUTURES, JP .
SOLAR ENERGY, 1983, 31 (02) :137-143
[3]   EXTRACTING OIL FROM SHALE USING SOLAR-ENERGY [J].
BERBER, R ;
FLETCHER, EA .
ENERGY, 1988, 13 (01) :13-23
[4]  
Figueiredo JL, 1986, CARBON COAL GASIFICA
[5]   SOLAR GASIFICATION OF BIOMASS USING OIL-SHALE AND COAL AS CANDIDATE MATERIALS [J].
FLECHSENHAR, M ;
SASSE, C .
ENERGY, 1995, 20 (08) :803-810
[6]   SOLAR GASIFICATION OF COAL, ACTIVATED CARBON, COKE AND COAL AND BIOMASS MIXTURES [J].
GREGG, DW ;
TAYLOR, RW ;
CAMPBELL, JH ;
TAYLOR, JR ;
COTTON, A .
SOLAR ENERGY, 1980, 25 (04) :353-364
[7]   The solar thermal decarbonization of natural gas [J].
Hirsch, D ;
Epstein, M ;
Steinfeld, A .
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, 2001, 26 (10) :1023-1033
[8]   OIL-SHALE GASIFICATION BY CONCENTRATED SUNLIGHT - AN OPEN-LOOP SOLAR CHEMICAL HEAT PIPE [J].
INGEL, G ;
LEVY, M ;
GORDON, JM .
ENERGY, 1992, 17 (12) :1189-1197
[9]  
JUNTGEN H, 1981, KOHLEVERGASUNG GRUND
[10]  
KABS H, 2001, P FUEL CELL HOM C LU, P197