Economical Study on a 10MW Scale Biomass Indirect Co-Combustion with Coal for Power Generation

摘要

Biomass indirect co-combust with coal for power generation is one of the feasible ways in China's energy policy in recent years. This technology could use high parameter units in coal-fired power plants, and thereby has a higher efficiency. Indirect co-combustion technology turns biomass into syngas in a gasifier first, then the syngas is sent in to the boiler and combust with coal for power generation. Compared with the direct co-combustion technology, indirect co-combustion technology could avoid the pollutants entered into the boilers and have little changes for the coal-fired boilers. Besides, the indirect co-combustion technology could easily monitor the volume, component and temperature of the syngas, and easier to get policy allowances (or credits). However, due to the allowances and the raw material cost having not been clear in different area of China, this technology could not be promoted widely in China. This study analyzed the economics of a 10MW scale fluidized bed biomass gasifier. Raw material costs, product price, and policy allowances were considered in this paper. The results show that the raw material costs and policy allowances could affect the profits obviously. Biomass co-combustion project could have a better benefit when biomass electricity price is 0.75Yuan/kwh. It is hard to profit without any allowances when the raw material cost is higher than 350 Yuan/t. Due to the high value of biochar and tar, the multi-generation mode would have higher benefit. Considering the raw material cost and labor cost have been risen in China in recent years, the profit of biomass power generation is reduced remarkablly. Multi-generation mode would increase the benefit of the project, and should be promoted more widely.