Efficient Synthesis of Isobutylene Dimerization by Catalytic Distillation with Advanced Heat-Integrated Technology

Abstract

For the purpose of resolving issues of high production costs due to targeting intermediate products from tandem reaction systems in the isobutylene (IB) dimerization process with tert-butanol as a polymerization inhibitor, a potentially sustainable catalytic distillation (CD) process is proposed as the base case for efficient continuous diisobutylene production in this paper. This study covers the extensive design of the novel CD process with 99 wt % diisobutylene and 90 wt % oligomers as the final products, using a simulation-based optimization framework on the simulator Aspen Plus with a FORTRAN subroutine of Langmuir–Hinshelwood model for kinetics. Furthermore, the advanced heat-integrated manufacturing process by exploiting catalytic dividing wall distillation and double-effect catalytic distillation with/without vapor-recompressed heat pump (DECD-VRHP) technologies achieves a total reduction in energy and cost, compared to the base case with rigorous optimal CD. The results showed that the DECD-VRHP scheme performs better with the largest total annual cost saving of about 34% among the heat-integrated schemes compared with the CD process. Overall results demonstrate that the DECD-VRHP technology is a promising approach for the synthesis of IB dimerization.