工业Fe-Mn催化剂上基于详细反应机理的F-T合成动力学模型 Ⅰ.烯烃再吸附动力学研究  

Detailed Kinetics Model of Fischer-Tropsch Synthesis over an Industrial Fe-Mn Catalyst Ⅰ. Kinetics Study on Olefin Readsorption

作　　者：滕波涛[1] 常杰[1] 刘颖[1] 张成华[1] 杨骏[2] 郑洪岩[1] 张荣乐[1] 白亮[1] 相宏伟[1] 李永旺[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 [2]暨南大学化学系,广东广州510632

出　　处：《催化学报》2005年第8期693-700,共8页

基　　金：国家高技术研究发展计划(863计划)项目(2001AA523010);中国科学院知识创新重大项目(KGCX1SW02);国家自然科学基金重大项目(20590360).

摘　　要：利用转篮式无梯度反应器,在工业FeMn催化剂上,在较宽的工业操作相关的反应条件下进行了FT合成反应动力学研究.首次提出了利用转篮式无梯度反应器反应气氛和反应温度均一的优势,将烃生成反应动力学的估算从传统的对烃生成和水煤气变换这两类发生在不同活性中心的反应同时进行估算的方法中分离出来,简化了烃生成动力学模型的计算.在基于亚甲基插入的亚烷基机理动力学模型基础上,考虑到乙烯与催化剂表面强的相互作用,将乙烯和乙烷的生成动力学参数单独计算.动力学模型计算的链增长、烷烃和烯烃生成的活化能均与文献报道值具有较好的一致性.由FT合成动力学模型计算的合成气消耗速率、甲烷生成速率和C5+的生成速率较好地与实验值吻合.通过动力学模型并结合实验结果分析发现,未考虑除化学反应之外的非本征因素的烯烃再吸附动力学模型不能够正确预测烃产物分布偏离ASF规律及烯烷比随碳数增加而下降的现象.A Fischer-Tropsch synthesis kinetics model based on the detailed reaction mechanism was studied in a continuous spinning basket reactor over an industrial Fe-Mn catalyst. Experimental conditions were varied as follows： temperature 533-573 K, reactor pressure 1.10-2.61 MPa, n（H2）/n（CO） feed ratio 0.67-2.05 and space velocity 0.66 × 10^- 3 -2.65 × 10^- 3 Nm^3. kg^- 1. s^- 1. It was the first time that a F-T synthesis kinetics study estimates the kinetics parameters of hydrocarbon formation rates separately by taking advantage of the uniformity of the working environment in the gradientless reactor, This method is different from the traditional wayin which the hydrocarbon formation and water-gas shift reaction are estimated simultaneously. On the basis of the CH2 insertion alkylidene mechanism, the kinetics parameters of ethene and ethane formation were separately calculated because the strong interaction of ethene with the catalyst surface can lead to the relatively low ethene selectivity. The calculated values of the activation energy for the chain growth and the formation of olefins and paraffins are in the range of the values reported in the literature. The syngas consumption rates, methane and C5＋ formation rates calculated by the kinetics model fit the experimental data well. The olefin readsorption and secondary reaction kinetics model that does not include the bulk effect cannot predict the decrease in the olefin/ paraffin ratio with increasing carbon number and the deviation of hydrocarbons from the ASF distribution.

关 键 词：费-托合成 动力学 烯烃再吸附 铁 锰 工业催化剂 

分 类 号：O643.31[理学—物理化学]