Reactive Distillation Based Macrokinetics Study On Isobutene Oligomerization

The macrokinetics study of isobutene (IB) oligomerization is very important for developing an alkylation process to produce the saturated product isooctane using the C4 streams as raw materials.In this paper, an A/Al2O3 catalyst used for C4 alkenes oligomerization was prepared by incipient impregnation method. The effect of the A loading on the IB conversion and diisobutene selectivity was studied in a high pressure stirred tank reactor, and 1.00%(metal element of A, wt) was found suitable for reactive distillation purpose. Moreover, under such A loading, the macrokinetics behaviors of IB oligomerization were investigated with eliminating the external diffusion. The effects of reaction temperature, catalyst loading and the concentration of IB were investigated, and the Langmuir-Hinshelwood type kinetic model of IB oligomerization was established based on the mechanism of IB oligomerization. Parameters of the kinetic model were determined by fitting the experimental data, and predictions from the model were good agreement with the experimental data.The feasibility study of oligomerization of IB in a reactive distillation column had been analyzed by using the Aspen plus software combined with the developed macrokinetics model. The influence of important design and operating parameters on the performance of the reaction in a reactive distillation were studied through process simulations. The recommended parameters are that:34 of the number of ideal stages,23 of the number of reactive stages, 1000 kg of the catalyst loading,24 of stage position of C4 feed,14 atm of the column pressure,6 of reflux ratio, and 0.3:0.7 of the feed composition (isobutene:n-butene, mol%).