Progress in coal-coupled biomass gasification technology for power generation

Carbon emission from the coal-burning power plant is the main source of CO₂ emitted in the China’s energy industry. Biomass power generation is deemed to be a carbon-neutral or even carbon-negative mode. Therefore, the development of coal coupled biomass gasification technology for power generation can help to achieve a coal substitution and carbon emission reduction and is a realistic and feasible path for maintaining a low-carbon coal power generation. In this context, an overview of three coal coupled biomass power generation technologies (the coal/biomass direct combustion of coal and biomass, the coal/biomass direct combustion coupled in parallel mode, and the coal direct combustion coupled with biomass gasification) has been conducted in this study. The characteristics of the above three technologies have been analyzed. Future development trends in the coal-burning coupled biomass gasification power generation technology have been put forward. The physicochemical adaptability of the feedstock and the influence of the feedstock on the gasifier are also studied based on the coupled gasification power generation technology. This work has emphasized the technological process of coal coupled biomass gasification power generation technology, including biomass transportation system, gasifiers (the technical characteristics, technical challenges and development direction of circulating fluidized bed gasifier (CFB), double fluidized bed gasifier (DFB), downdraft fixed bed gasifier, updraft fixed bed gasifier, crossdraft fixed bed gasifier and chain grate have been analyzed), gas cooling system, gas-pressurized transportation system, combustion system and gas purification system. The energy utilization efficiency analysis, economic analysis and environmental benefit analysis of the technology have been carried out. The analysis obtained would provide a theoretical reference and technical support for the research and application of coal-coupled biomass power generation technology. In addition, a series of national policies to promote coal coupled biomass gasification power generation technology and the current successful cases of coal coupled biomass gasification power stations are also presented. Finally, the challenges and future development of coal coupled biomass power generation technology have been prospected.