成型玉米秸秆气化的热重分析及动力学研究

Study on Thermogravimetric Analysis and Kinetics during Gasification of Molding Corn Straw

以成型玉米秸秆为原料,采用热重分析方法,探讨气化剂CO2浓度和物料含水率对成型玉米秸秆气化过程中热失重的影响,并从动力学角度对气化特性进行分析。结果表明:生物质气化过程可分为水分析出、纤维素/半纤维素/木质素等有机物分解、焦炭气化三个阶段;CO2浓度为30%时,气化反应程度加剧,活化能和频率因子亦达到最大值;气化反应转化率随生物质含水率增大先增加后减少,少量水分促进气化反应,水分含量过高抑制气化反应;高含水量的生物质在气化过程中水分蒸发能耗比化学反应能耗大。

The effects of CO2 concentration and moisture content on the thermal weight loss during the gasification of molding corn straw were analyzed using the thermogravimetric analysis method,and the gasification characteristics were analyzed from the kinetic point of view.The results showed that the biomass gasification process could be divided into three stages:water evaporation,cellulose/hemicellulose/lignin and other organic matter decomposition and coke gasification.When the concentration of CO2 was 30%,the degree of gasification reaction was intensified,and the activation energy and frequency factor also reached the maximum value.The conversion ratio of gasification reaction increased first and then decreased with the increase of biomass water content.A small amount of moisture promoted gasification reaction,but the moisture content was too high to inhibit gasification reaction.The energy consumption of water evaporation was greater than the energy consumption of chemical reactions during the gasification of the biomass with high water content.