Optimization and heat integration of hybrid R-HIDiC and pervaporation by combining GA and PSO algorithm in TAME synthesis

The TAME production process involves two main steps. The first step pertains to the reactions that lead to the synthesis of TAME, and the second step to the separation of TAME and recovery of methanol. Part of the TAME reaction and separation is carried out in a reactive distillation (RD) column. The product at the top of the RD column is a methanol- and C-5-containing azeotropic mixture which can be isolated through pressure swing distillation (PSD) and extractive distillation (ED) methods. In this paper, the mixture was isolated through the pervaporation (PV) process, and all parameters related to RD and PV were considered as optimization variables, in particular the PV-related parameters such as the permeate stream pressure, the number of modules, and the temperature of inflow to each module. All variables were optimized simultaneously. The GA and PSO algorithms were combined to optimize the process and, additionally, total annual cost (TAC) was used as the objective function. The internally heat integrated distillation column (HIDiC) method was used to reduce the RD column energy costs, and the number of heat exchangers between the two rectifying and stripping sections was obtained using the optimization algorithm. The results showed that the hybrid PV/R-HIDiC process with heat integration was the best arrangement, resulting in a TAC reduction of 30% and 40% compared to the hybrid PV/RD process and the hybrid PSD/RD process, respectively. In this case, the number of trays in rectifying and stripping sections is respectively 22 and 6. The number of heat exchangers obtained by R-HIDiC method is 5, the number of PV modules is 11 and permeate pressure equals 18 as the most important parameters obtained from the optimization algorithm.