生物质蒸汽气化模拟研究

摘要

Based on chemical thermodynamic software of GasEQ, this study investigated the influence of H2, CH4 and CO in syngas composition by temperature, ratio of steam to biomass (S/M) and concentration of carbon dioxide (CO2). Low heat value of cold syngas (LHV) and heat conversion efficiency (q), especially the external heat supply during q calculation were also accounted. The results of simulation showed: LHV generally decreased with the increasing temperature, and q was significantly up then slightly down. An optimistic temperature for steam-gasification was assumed in the range of 800~900 ℃. With higher S/M, more H2 was produced, and the percentage of H2 was higher in syngas, while LHV was reduced, and q likely first increased and then decreased with the increasing of steam. So a most economic value of S/M (0.6) possibly existed in real process. When CO2 was added into reagent gas, less char was remained in products, higher content of CO and lower percentage of H2 were observed in the cold syngas.%利用化学热力学软件(GasEQ)模拟了生物质蒸汽气化过程中温度、水蒸气与物料质量比(S/M)以及CO2浓度对H2,CH4和CO的影响；研究了冷合成气低位热值(LHV)和气化能量转化效率(q)随各参数变化的规律,并且考虑了外部能量的消耗.模拟研究得到:随着温度的升高,合成气的LHV总体表现出降低,并且q先增加后微弱下降,认为存在一个最优的气化温度(800～900℃)；高/M有利于H2的生成,提高H2的体积浓度,但水蒸气的增加,降低了LHV值,并且q先增加后减少,因为水蒸气会消耗大量外部能量,存在一个最经济的气化S/M;随着反应气中CO2浓度的升高,促进了生物质气化,并使CO浓度升高和H2浓度降低.