Abstract Small-scale biomass power generation will play an important role in ensuring the regional power supply by using the local biomass resource and protecting the environment in the future. In this study, a small-scale high-efficient combined heat and power generation system with a separated-type biomass gasification process combining the energy/exergy recuperation is proposed for the first time. The spatial subdivision of the processes for the biomass pyrolysis, char combustion, tar reforming and catalyst regeneration is adopted by using a separated-type biomass gasifier design to realize the optimization of each conversion step and improve the whole system performance. To obtain the maximum power generation efficiency, the energy flow and exergy flow in the system are analyzed in details and the operating condition of the gasification system is optimized. The results demonstrate that the relatively low temperature as well as low steam/carbon ratio in the tar reformer should be conducive to the improvement of energy and exergy efficiencies. In the optimum operation condition, the biomass input of 548.86 kW (higher heating value) could generate 263.65 kW of electrical power with the total energy and exergy efficiencies of 37.9% and 43.2%, respectively, in which 153.44 kW of energy could be recuperated back to the gasification process by air and steam with 136.56 kW of energy obtained from gas turbine exhaust to enhance the whole power generation efficiency. It is expected to provide a new design concept for the development of high-efficient small-scale biomass gasification system for the combined heat and power generation.

中文翻译：

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一种具有能量/火用回收的基于生物质的小型发电系统

摘要 小规模生物质发电将在未来利用当地生物质资源保障区域电力供应和保护环境方面发挥重要作用。本研究首次提出了一种小型高效热电联产系统，采用分离式生物质气化工艺，结合能量/火用回收。生物质热解、焦炭燃烧、焦油重整和催化剂再生过程的空间细分，采用分离式生物质气化炉设计，实现各转化步骤的优化，提高整个系统性能。为了获得最大的发电效率，详细分析了系统中的能量流和火用流，优化了气化系统的运行条件。结果表明，焦油重整器中相对较低的温度以及较低的蒸汽/碳比应该有利于提高能量和火用效率。在最佳运行条件下，548.86 kW（较高热值）的生物质输入可产生263.65 kW的电能，总能量和火用效率分别为37.9%和43.2%，其中可回收能量153.44 kW从燃气轮机排气中获得136.56千瓦的能量，用于空气和蒸汽的气化过程，以提高整体发电效率。