基于能值理论的生物质发电系统评价

Evaluation of Biomass Power Generation Systems Based on Emergy Theory

应用能值理论,借助能值转换率ηTr、能值产出率ηEYR、环境负载率ηELR、能值可持续指数ηESI等指标,对25MW直燃、2×12MW国产直燃、4MW中型气化、15MW大型气化和22MW生活垃圾焚烧发电等5种有代表性的生物质发电系统进行分析和比较。结果表明:5种生物质发电系统的ηEYR虽然并不明显高于燃煤发电,但ηELR都很低,均属于低环境负荷系统。生活垃圾焚烧发电系统的ηTr最大,单位数量的电力所需投入的能值最多。气化发电投资、运行投入的能值比例较低,ηEYR、ηESI均高于其他几种生物质发电。但生物质直燃和生活垃圾焚烧发电系统富有活力和发展潜力,可在较长时间内持续发展。

Based on the emergy theory, 5 representative biomass power generation systems including 25 MW direct combustion, 2×12 MW direct combustion, 4 MW medium-sized gasification, 15 MW large-scale gasification and 22 MW municipal solid waste （MSW） incineration for power generation systems were analyzed and compared with indices of transformity （ηTr）, emergy yield ratio （ηEYR）, environmental loading ratio （ηELR）, emergy sustainability index （ηESI）. The results show that ηEYR for all the 5 biomass power generation systems are not significantly greater than coal power generation, but all of them are low environmental load systems because of their lower ηELR. The ηTr of 22 MW MSW incineration for power generation system is highest. It means the most emergy input is required per output. Since the emergy proportion of investment and operation cost of gasification power generation systems are lower than the other systems, their ηEYR and ηESI are relatively higher. However, direct combustion and MSW incineration for power generation systems are in the potential and developing process which can support long-term sustainability.