Inter-integration reactive distillation with vapor permeation for ethyl levulinate production: Modeling, process analysis and design

Abstract

The reactive-vapor permeation-distillation (R-VP-D) hybrid configuration is a newly designed inter-integration concept firstly proposed for the production of ethyl levulinate (EL) by esterification of ethanol and levulinic acid in this paper. In the R-VP-D configuration, the VP membrane module is inserted to the reaction section of the reactive distillation (RD) column, of which the product water is in-situ removed by the vapor permeation (VP) to promote the performance of esterification RD process. The proposed R-VP-D configuration is modeled by Aspen Plus V8.4 using the two-dimensional VP model built in ACM®, and the inserting position of single or double VP modules is found by contrast trials, where both the conversion rate and purity of product can reach the industrial production standards. As a result, the proposed novel R-VP-D configuration is feasible, with over 21.6% and 31.4% reduction in TAC and total duty as compared to the configuration which only applies an extra distillation column to separation and recycle the excess ethanol without azeotrope separation, and with 13.5% and 21.5% reduction in TAC and total duty as compared to the hybrid configuration where the vapor permeation is coupled outside the RD column. The result also shows the advantage of the proposed R-VP-D process for potentially leading to the development of new integration processes and applications.