微通道费-托合成反应规律及本征动力学

摘要

A microchannel reactor was used to study reaction law and kinetics of Fischer-Tropsch synthesis over cobalt-based catalyst.The experiment results show that the effects of internal and external diffusion on Fischer-Tropsch synthesis can be eliminated with small particle size of catalyst and high space velocity.The value of the apparent activation energy obtained is relatively high.Increasing n(H2) (CO) from 1.0 to 3.0 significantly increases CO conversion and volume space-time yield of C5+.However,effects of pressure (in the range of 1.0-5.0 MPa) and space velocity (in the range of 20000-60000 h-1) on the selectivity are not obvious.Intrinsic kinetic data was collected over Co/Al2O3 under the following operation conditions:temperature of 210-230℃,pressure of 2.0-3.0 MPa,n(H2)(CO) of 1.5-2.5,GHSV of 40000 h-1.The optimal intrinsic kinetic equation was obtained by fitting and model discrimination,with mean absolute relative residuals of 7.77 ％.The model predicts the reaction rate effectively.%在微通道反应器中,进行了钴基催化剂的费-托合成反应规律和本征动力学研究.结果表明,在微通道反应器中,采用较小的催化剂粒径和较大的体积空速可以削弱内外扩散对费-托合成性能的影响,反应的表观活化能较高;将n(H2)(CO)从1.0提高到3.0能够显著提高CO的转化率以及C5+的收率;而压力在1～5 MPa范围内以及空速在20000～60000 h-1范围内对选择性的影响并不明显.在温度210～230℃、压力2.0～3.0 MPa、n(H2)(CO)为1.5～2.5、体积空速为40000 h-1的条件下采集Co/Al2O3催化剂的本征动力学数据点,通过对备选模型进行拟合和比较得出最优的本征动力学方程.模型平均相对偏差为7.77％,模型能够对反应速率进行有效的预测.