Effect of ethanol on selective oligomerization of isobutene and the simulation of reactive distillation process

Abstract

This paper investigates the selective oligomerization of isobutene in mixed C4 using ethanol as an inhibitor. The effects of ethanol/isobutene, reaction temperature, and reaction space velocity on isobutene oligomerization were examined using two β molecular sieve catalysts. The results indicate that the optimal reaction conditions, at the same calcination temperature, are as follows: The mass ratio of ethanol to isobutylene is 20%, the reaction pressure is 1 MPa, the reaction temperature is 65°C, the reaction space velocity is 2 h−1, the dimerization product C8 has fewer types, and the selectivity can reach over 15%. After adding ethanol, there is a significant inhibitory effect on n‐butene. Furthermore, we used reactive distillation technology to simulate isobutene oligomerization. By optimizing the sensitivity of the tower's operating conditions, we obtained the optimal operational parameters of the tower. Under optimal operating conditions, the conversion rate of isobutene can reach over 80%. The mass fraction of C8 in the oligomerization product accounted for 57.44%, C12 accounted for 8.29%, and ETBE accounted for 34.23%. The reactive distillation technology can improve product selectivity.