生物质混合物与煤共热解的协同特性

Interaction Performance of Co-pyrolysis of Biomass Mixture and Coal of Different Rank

该文选取了秸秆、稻壳、玉米芯、木屑、沙柳枝和叶、旱柳枝和叶、紫花苜蓿、芦苇、碱草等13种农业和林业废弃物、草木类及不同生长期的薪炭林等生物质,按等比例混合制备成粉状生物质混合物,在不同的工况下采用热重分析仪,分析研究生物质混合物与典型的褐煤、贫煤和烟煤煤粉的单独热解特性,以及分别与3种煤均匀掺混20％、33％与50％生物质混合物的共热解特性,合理定义了共热解中煤挥发分开始热解的温度。对热解试验数据与计算特性参数的分析表明:不同比例生物质混合物和不同煤化程度煤在共热解过程中,产物的产率基本等于单独热解生物质和煤的产物产率的加权平均值;与单独热解试验结果比较,生物质混合物与煤挥发分的各自析出开始和终止温度均随着生物质掺混比例不同与煤种不同有不同程度的变化,并对其规律进行了机理分析,认为生物质与煤共热解过程中存在协同作用。

13 different kinds of biomass were used in this study, including straw, rice hull, maize cob, saw dust, branch and leaves of salix psammophia and salix matsud, alfalfa, bulrush, wildryegrass etc. They were pulverized and blended into one biomass mixture at the same proportion for each component. The thermogravimetric analyzer was used to get the pyrolysis performance of the biomass mixture and each coals, as well as the co-pyrolysis performance of the biomass mixture with three different coals （lignite, sub-bituminous and bituminous）. The biomass mixture were blended with the different coals at the percentages of 20%, 33% and 50% respectively. The initial temperature of coal volatile release in the co-pyrolysis process is adequately defined. The results show that both the initial temperature and the terminal temperature of coal volatile release in the co-pyrolysis process are dependent of the blending ratio as well as the coal rank, and more or less variations of the temperatures are found by comparing with the individual pyrolysis performance of the biomass mixture and each coals. The interaction effects in the co-pyrolysis of biomass and coal are suggested.