
52
应用能源技术
doi:10.3969/j. issn. 1009 3230.2014.10.014
2014年第10期(总第202期)
利用绝对反应速率理论研究生物质热解机制
杨建蒙,班彩英,鲁许警
(华北电力大学能源动力与机械工程学院,河北保定071000)
摘要:文章采用热重分析仪,分别以10、20、40、50℃/min的升温速率对玉米秸秆和松木屑的不同粒径进行了热解实验。利用绝对反应速率理论,采用一级反应模型,并结合Coats-Redferm积分法及最小二象拟合法对主反应区反应机理进行深入研究,利用实验数据求取了活化恰H"、特征点处的活化端4S"、活化自由能△G"和反应速率常数k,并分析不同升温速率及不同粒径对反应的影响。结果表明:化学反应速率是由活化处和活化炳共同决定的,利用这些参数可预测其难易程度。升温速率增加,活化烩增大,活化煸增大,活化自由能增加,所需反应能级增大,热解时间缩短;粒径减小,活化烩降低,热解越容易且热解越充分。
关键词:生物质;绝对速率理论;活化;活化满
中图分类号:TK6
文献标志码:A文章编号:1009-3230(2014)10-0052-07
UsetheTheoryof AbsoluteReactionRatetoStudyBiomass
PyrolysisMechanism
BAN Caiying, LU Xu -ao, YANG Jian meng
(North China Electric Power University College of Energy Power and Mechanical Engineering,
Baoding071000,HebeiProvince,China)
Abstract: This paper use TGA to study on the reaction kinetics of sawdust pyrolysis. Heating rate are 10,20,40,50 °C/min to carry out Pyrolysis experiment for different particle sizes of maize straw and pine. Using the theory of absolute reaction rate, the first order reaction model and combined with the Coats - Redfem integral method and least squares fitting method for the main reaction mechanism were studied.Use the experimental data to calculate the activation enthalpy, and entropy of activation, activation free energy and reaction rate constant. This paper analyzes the different heating rate and particle size what have effects on the reaction. The results show that: the chemical reaction rate is determined by the activation enthalpy and entropy of activation. the use of these parameters can predict the degree of difficulty. With the heating rate increases, activation enthalpy increases, activation entropy increases, activation free energy increases ,and the required response power level increases, the pyrolysis time is shortened. With the particle sizes decreases, the activation enthalpy lower, and pyrolysis more easily and more fully.
Key words: Biomass; Absolute reaction rate theory; Activation enthalpy; Entropy of activation
0
引言
生物质作为一种可再生且洁净的能源,其具
收稿日期:201407-10
修订日期:201408-21
作者简介:班彩英(1988-),女,河北省保定市华北电力大学能
源动力与机械工程学院2012级硕士研究生。
万方数据
有二氧化碳零排放,二氧化硫及氮氧化物排放量少的优点,并且像玉米秸秆、稽壳、木屑等生物质能源储量丰富,用途广泛。其中热化学转化法被高效利用。可以将其转化为二次能源,即用于热能或发电,生产气体燃料、液体燃料和固体燃料。