生活垃圾和玉米秆混合热解动力学及产物分布

为探讨生活垃圾和玉米秆共热解过程中的协同关系和产物分布,采用热重分析仪对生活垃圾、玉米秆及其混合物进行了热解实验研究,并进行动力学计算。结果表明,混合热解可分为脱水、热解、炭化、焦催化气化4个阶段,前3个阶段与单独热解过程类似,第4个阶段与单独热解相比失重明显增加,表明混合热解过程中存在协同效应;混合物热解的实际活化能为28.492 kJ/mol,低于单独热解及其混合物热解理论活化能,可见混合热解利于热解反应进行。为明晰混合热解对热解反应的促进作用,利用固定床热解实验,研究了混合比例对产物产率和热解气各组分产率的影响。结果表明,在不同混合比例下,固液实际产率低于理论值,而气体实际产率则比理论值高;混合物料热解气中H2、CH4、CO2产量均高于其理论值,而CO产量却相反,低于其理论值。

Pyrolysis kinetics and product distributions of municipal solid waste and corn stalk blends

To investigate synergetic effects and product distributions of municipal solid waste (MSW) and corn stalk (CS) blends on pyrolysis, the pyrolysis characteristics and dynamic analysis of MSW, CS and their mixtures were examined by thermal gravimetric.The results indicated that co-pyrolysis process can be divided into four steps:losing water, main pyrolysis, carbonization and catalytic gasification of char.The first to third stages were similar with MSW and CS alone pyrolysis process, and the results of the fourth stage indicated that there exist synergetic effects of MSW and CS during the co-pyrolysis process.The actual value of activation energy of the mixture (28.492 kJ/mol) was lower than those of MSW, CS and the theoretical calculation of their blends.There exist synergetic effects of adding CS on MSW pyrolysis.To further clarify the role of the mixtures on pyrolysis, the effect of the different blending ratios on the pyrolysis product yields and compositions of the gaseous products were investigated in the fixed-bed.The results indicated that under the different blending ratio conditions, the char and liquid yields were lower than the theoretical values calculated on pyrolysis of each individual MSW and CS, and consequently the gas yields were higher.The yields of total gas and H2, CH2 and CO2 obtained from the co-pyrolysis under the different blending ratio conditions were higher than those of MSW and CS alone, and the yields of CO were lower.