Co/ZrO_2/SiO_2催化剂费-托合成反应动力学研究 Ⅱ.动力学模型的构建和回归  

Detailed Kinetic Study of Fischer-Tropsch Synthesis on Co/ZrO_2/SiO_2 Catalyst Ⅱ.Construction and Regression of Kinetic Models

作　　者：常杰[1] 滕波涛[1] 白亮[1] 陈建刚[1] 张荣乐[1] 徐元源[1] 相宏伟[1] 李永旺[1] 孙予罕[1] 

机构地区：[1]中国科学院山西煤炭化学研究所煤转化国家重点实验室

出　　处：《催化学报》2005年第10期859-868,共10页

基　　金：国家自然科学基金重大项目(20590361);山西省自然科学基金(20021024)资助

摘　　要：在典型的Co系催化剂工业操作条件范围(T=473～503 K,p=1.5～4.0 MPa, H2/CO体积比=1.0～3.0)内,采用等温积分固定床反应器对Co/ZrO2/SiO2催化剂进行了F-T合成反应动力学研究. 依据详细可靠的基元反应机理,按照Langmuir-Hinshelwood-Hougen-Watson动力学推导方法,获得了Co系催化剂上基于详细反应机理的动力学模型. 通过动力学实验数据的回归分析,发现基于COs直接解离并以烷基为链增长中间体的表面碳物种机理的动力学模型可以较好地描述Co/ZrO2/SiO2催化剂上的F-T合成反应结果,该模型可自洽地描述F-T合成过程中的合成气消耗和烃产物分布状况,且获得的反应活化能等关键动力学参数与文献报道的理论结果基本一致.The detailed kinetics of the Fischer-Tropsch （F-T） synthesis on the Co/ZrO2/SiO2 catalyst was studied in an integral fixed-bed reactor. The experimental conditions were varied as follows： T = 473-503 K, p = 1.5-4.0 MPa and H2/CO feed ratio= 1.0 - 3.0. Based on the reliable mechanisms obtained in Part I of this series study, ten sets of Langmuir-Hinselwood-Hougen-Watson type kinetic models were derived, in which both the alkyl and alkylidene carbon chain propagation pathways of the F-T synthesis were considered. In construction of the kinetic models, COs direct dissociation and hydrogen-assisted dissociation were assumed as the ratedetermining steps. The polymerization character of the F-T synthesis and its irreversibility were also accounted in the model derivations. Using these kinetic models, the information of syngas consumption and product distribution is obtained self-consistently. After regressions of the candidate models, the results of discriminations show that the kinetic model based on the alkyl propagation pathway, starting from the COs direct dissociation, can describe the reaction performance better than the other models. The COs dissociation is an important elementary step to determine the overall rates of the F-T synthesis reactions with an activation energy of 86.48 kJ/mol on the Co/ZrO2/SiO2 catalyst. The kinetic parameters are in agreement with the reported values obtained from theoretic research.

关 键 词：钴基催化剂 费-托合成 反应动力学 动力学模型 

分 类 号：O643.32[理学—物理化学]