Energy-efficient reactive distillation by internal heat integration in a partial double annular column

Abstract

This study presents a strategy for the internal heat integration of reactive distillation (RD) columns for concurrently producing two esters. Because of a significant temperature difference in the two reactions, the two RD columns process with each single reaction occurring in the respective column has lower energy consumption than the direct sequence consisting of one RD column followed by a non-RD column. Thus, internal heat integration in a partial double annular configuration is introduced on the basis of the two RD columns process. In the new annular RD configuration, heat is transferred from the outer column shell having a high-temperature exothermic reaction to the inner shell with a low-temperature endothermic reaction. By using the concept of pinch temperature, we determine the heat transfer stages to secure sufficient temperature driving force. For the same product purity and reaction extent, the internal heat integrated distillation column shows lower internal flowrate and energy consumption than the other processes.