生物质玉米芯热解动力学实验研究

以玉米芯为对象,利用热重-质谱联用技术,以高纯氩气为载气对其进行了详细的热重分析研究。通过对10℃/min和30℃/min升温速率及其不同温度下的失重曲线分析,发现玉米芯的主要失重温度区间为200~400℃,峰值温度为328~345℃。随着升温速率的提高,玉米芯热解的初始温度升高,热解向高温侧移动。同时通过质谱分析获得了温度和升温速率对热解气化产物的影响规律。在此基础上建立了热解动力学模型,并根据实验数据对模型进行了求解,结果表明玉米芯热解在低温段属一级反应而在高温段属三级反应。

EXPERIMENTAL STUDY ON CORN COB PYROLYSIS AND KINETIC ANALYSIS

The thermo-gravimetric analysis was applied to investigate the pyrolysis process of Corn Cob in high purity argon atmosphere with the heating rates of 10℃/min and 30℃/min,respectively.The results show that derivative thermo-gravimetry(DTG) curve of Corn Cob distributes over 200-400℃ and peak temperature is about 328-345℃.The whole pyrolysis process consists of three distinct phases.Start temperature of pyrolysis increases and pyrolysis curves moved to higher temperature region as the heating rate increasing.The gaseous curves show that lower heating rate can produce more H2,and the higher one generates more CO,CO2 and CH4.In gasification cracking stage,Corn Cob shows different pyrolysis reaction mechanism.A two-step different reaction pyrolysis kinetics model was developed and the related kinetics parameters were determined.In lower temperature region,the reaction order is 1,reaction energy distributes between 100.36 and 100.79kJ/mol and pre-exponential factor is in the range of 2.31×1010 to 4.84×1010/min.In higher temperature regien,the reaction order is 3,reaction energy distributes between 70.86 and 76.75kJ/mol and pre-exponential factor is in the range of 9.7×105 to 1.68×107/min,which is in the range of that reported previously.