多孔物质气固反应动力学研究  

Kinetic study of reaction of porous solids

作　　者：刘文钊[1] 余剑[1] 张聚伟[1] 高士秋[1] 许光文[1] 

机构地区：[1]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：《中国科学：化学》2012年第8期1210-1216,共7页SCIENTIA SINICA Chimica

基　　金：科技部重大仪器专项(2011YQ120039);中国科学院国际合作项目(0829011198);国家高技术研究发展计划(863计划;2010AA065004);国家自然科学基金(21106156;21006110)资助

摘　　要：利用自主研制的微型流化床反应分析仪(MFBRA)在等温条件下测试了高比表面活性炭氧化反应,并根据基于固体转化的热分析动力学方法及考虑气体在微孔内扩散与反应的应用化工动力学方法求算了动力学参数.在内外扩散抑制最小化的实验条件下,粒径小于5μm的活性炭在700～1000℃的燃烧反应动力学研究表明,根据微型流化床中实验数据,采用等温热分析动力学方法求算得内扩散控制区活化能约为95kJ/mol;引入化工动力学方法中的随机孔模型对低温区等温燃烧数据拟合,可得孔结构参数在0.17m?3左右,反应活化能为178kJ/mol,约为内扩散反应活化能的两倍,最为接近本征的碳燃烧反应活化能.This work focused on the research of reaction test and kinetic calculation method for the combustion of a high-surface-area carbon. Experiments have been performed by Micro Fluidized Bed Reaction Analyzer （MFBRA）, which was developed by IPE, CAS, and commercial thermogravimeter under isothermal and programmed heating conditions, respectively. With these methods, for the 0-5 μm particles in a MFBRA in the air flow rate of 1.3 L/min, the activation energies were calculated using thermal kinetics analysis on solid conversion and applied chemical kinetics on gas diffusion and reaction in micro pores. Using thermal kinetics analysis method （FWO equation） to calculate the programmed heating test data by TG, the activation energy is about 137 kJ/mol inclusion the reaction and gas diffusion control. Using thermal analytic isoconversional method to calculate the experimental data in MFBRA, the activation energy is about 95 kJ/mol. Meanwhile, the activation energy, which was obtained using a random pore model to calculate the isothermal experimental data, is about 178 kJ/mol with a structure parameter about 0.17 m^-3. This value is about twice of that from thermal analytic isoconversional method, and higher than the non-isothermal TGA results, and be closer to the intrinsic value.

关 键 词：多孔物质 微型流化床 热分析动力学 随机孔模型 

分 类 号：O643.12[理学—物理化学]