微型流化床与热重测定煤焦非等温气化反应动力学对比  

Comparation of non-isothermal coal char gasification in micro fluidized bed and thermogravimetric analyzer

作　　者：王芳[1] 曾玺[2] 王永刚[1] 余剑[2] 岳君容[2] 张建岭[2] 许光文[2] 

机构地区：[1]中国矿业大学(北京)化学与环境工程学院,北京100083 [2]中国科学院过程工程研究所多相复杂系统国家重点实验室,北京100190

出　　处：《化工学报》2015年第5期1716-1722,共7页CIESC Journal

基　　金：科技部重大仪器专项(2011YQ120039);国家自然科学基金项目(21306209);中国科学院战略性先导科技专项'低阶煤清洁高效利用关键技术与示范'项目(XDA07050400)~~

摘　　要：利用微型流化床反应分析仪(MFBRA)和热重分析仪(TGA)比较煤焦与CO2的非等温气化反应特性,并利用单一升温速率法和组合升温速率法计算反应动力学数据。结果表明:升温速率对半焦非等温气化过程有重要影响,随着升温速率的增大,起始反应温度和最大反应速率对应的气化温度增加,同一气化温度下的碳转化率降低,而且利用单一升温速率法求取气化反应的活化能逐渐减小。与TGA相比,同一升温速率下,MFBRA中半焦气化反应的起始反应温度和最大反应速率对应的反应温度明显较小,而且升温速率越大差异越显著。无论是单一升温速率法(升温速率≥5℃·min-1)还是组合升温速率法,TGA测得的动力学数据均明显小于MFBRA测得的动力学数据。高升温速率下(升温速率≥5℃·min-1)半焦在TGA和MFBRA中非等温气化行为和动力学数据的差异很可能与MFBRA内较好的热量传递和受扩散的抑制作用较小有关。The non-isothermal gasification behavior of coal char with CO2 was comparatively studied in the newly developed micro fluidized bed reaction analyzer （MFBRA） and a commercial thermogravimetric analyzer （TGA）. The reaction kinetics data were calculated according to the methods of single heating rate and combination heating rate. The experimental data demonstrated that heating rate had obvious influence on coal char gasification. Increasing heating rate evidently increased reaction initiation temperature（Tx≈0）, and reaction temperature corresponding to the maximum reaction rate（RmaxT）, but it gradually decreased char conversion at a given temperature and the activation energy estimated by the method of single heating rate. Comparing the results from TGA and MFBRA at the same heating rate clarified that bothTx≈0 andRmaxTwere relatively lower for MFBRA, and the higher the heating rate, the larger the difference between MFBRA and TGA. The measurement using MFBRA led to higher activation energy for char-CO2 gasification, no matter the adopted estimation method of single heating rate （≥5℃·min-1） or combination heating rate. The difference in kinetics data tested by TGA and MFBRA at higher heating rate （≥5℃·min-1） could be much related to better heat transfer and lower diffusion inhibition.

关 键 词：微型流化床 热重 半焦 气化 反应动力学 非等温反应 数值分析 

分 类 号：TQ546[化学工程—煤化学工程]