内扩散控制下异丁烯齐聚反应宏观动力学研究

Study on lumped macro-kinetics of isobutene oligomerization under the control of inner diffusion

利用工业硅铝小球固体酸催化剂,排除了外扩散的影响后,在高压微反实验装置上进行了异丁烯齐聚反应的宏观动力学研究。结果表明,在相同的实验条件下,反应的宏观动力学行为与本征动力学行为有较大的不同,异丁烯的反应级数受内扩散影响由2级变为1.5级,异辛烯的反应级数则为0级。在本征动力学方程的基础上,利用集总的方法建立了内扩散控制下的异丁烯齐聚复杂反应动力学模型,并采用数值计算方法对该模型进行了求解,获得了异丁烯齐聚的集总宏观动力学方程。模拟结果与实验结果吻合良好。

By using the commercial silicon-aluminium solid acid catalyst and eliminating the effect of external diffusion, the macro-kinetlcs of isobutene oligomerization was studied with a high pressure micro-reactor. The results show that the reactive characters of macro-kinetics are different from that of intrinsic kinetics under the same experimental conditions. The isobutene dimeric reaction follows 1.5 order reaction because of the effect of inner diffusion, and isooctane dimeric reaction follows zero order reaction. Based on the mechanism equations of intrinsic kinetics, the complicated lumped macro-kinetics model under the control of inner diffusion resistance was developed. The model was solved by numerical calculation. The simulated data by the model agrees well with the experimental results.