生物质水蒸气气化的能量分析和分析

ENERGY AND EXERGY ANALYSES OF BIOMASS STEAM GAISIFICATION

以生物质水蒸气气化制取燃气和富氢气体为研究对象,利用Aspen Plus软件建立其过程仿真模型并进行验证.研究气化温度、气化压力、水蒸气与生物质配比（S/B）对气化气成分、高位发热量、（火用）值及系统能量效率、（火用）效率的影响,并对比有、无热量回收两种情况下的能量利用效率.研究结果表明：较低的气化温度、S/B及较高的气化压力可提高气化气热值,有利于制取燃气;适中的温度（750～850℃）、常压和较高的S/B有利于制取富H2气体,但S/B的增大会显著降低系统能量效率和（火用）效率,故S/B不宜超过1.3;系统的能量效率高于对应的（火用）效率,热量回收对于提高系统能量效率和（火用）效率有重要作用.

Taking the biomass steam gasification for preparing fuel gas and hydrogen-rich gas as the research object, the simulation model of the process was set up and validated with Aspen Plus software. The effect of gasification temperature, gasification pressure, and steam to biomass ratio （S/B） on gasification gas component, HHV, exergy value, the system energy efficiency and exergy efficiency was investigated. The energy efficiency and exergy efficiency were compared for cases with and without heat recovery. The results show that lower gasification temperature and S/B, higher pressure can improve heat value of gasification gas and favor production of fuel gas. Moderate temperature （750- 850 ℃ ）, atmospheric pressure and higher S/B favor the production of H2-rich gas. However, increasing S/B will reduce the energy efficiency and exergy efficiency significantly, it shouldn＇t be larger than 1.3. The energy efficiency of system is higher than the corresponding exergy efficiency, and heat recovery is important to improve the energy efficiency and exergy efficiency.