煤耦合生物质气化发电技术研究进展

Progress in coal-coupled biomass gasification technology for power generation

煤电碳排放是我国能源消费碳排放的主要来源。生物质发电是一种零碳甚至可以是碳负排放的电力生产方式,因此发展煤耦合生物质气化发电技术可实现煤炭减量替代与碳减排效应,是一条煤电走向低碳化的可行路径。基于此,综述了煤耦合生物质发电的3种技术——直燃耦合发电技术、并联耦合发电技术和气化耦合发电技术,解析了3种技术的特点,提出了煤耦合生物质气化发电技术的优势,并基于气化耦合发电技术研究了原料的物理化学性质适应性及原料对气化炉的影响。重点解析了煤耦合生物质气化发电技术的工艺流程,包括生物质原料储存输送系统、气化炉(循环流化床(CFB)气化炉、双流化床(DFB)气化炉、下吸式固定床气化炉、上吸式固定床气化炉、横吸式固定床气化炉和链条炉)、燃气冷却降温系统、燃气加压输送系统、燃气耦合燃烧系统和气体净化系统,并进行了能源利用效率、经济性与环境效益分析,以期为煤耦合生物质发电技术的研究与应用提供理论参考与技术支持。此外,还综述了国家为推进煤耦合生物质气化发电技术出台的一系列政策及当前煤耦合生物质气化发电站的成功案例。最后对煤耦合生物质气化发电技术存在的挑战和未来的发展进行了展望。

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, gasi-fiers (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 sys-tem 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 technic-al 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 develop-ment of coal coupled biomass power generation technology have been prospected.