New hybrid reactive-extractive distillation with two reactants for separating water-free ternary azeotropic mixtures

Abstract

Research on reactive-extractive distillation for azeotropic mixtures has grown in recent years, particularly for water-containing ternary systems. However, its application to water-free ternary azeotropes remains limited, especially when all components must be recovered without conversion. Motivated to address this limitation, this research introduces a new reactive-extractive distillation system designed for this purpose. This research will contribute to broadening the scope of this intensified separation technology, enabling its use in more complex and valuable industrial mixtures. The system is applied to the separation of a methanol/methyl acetate/ethyl acetate mixture. It includes a reactant stream consisting primarily of water and glycidol, with a small amount of sulfuric acid as a catalyst. Optimization using a genetic algorithm, with total net revenue as the objective, was conducted. The results show that this configuration has a slightly higher total annual cost (2.18 %) and a lower total net revenue (10.4 %) compared to reactive distillation with pre-separation. However, unlike the reactive distillation configuration, which converts methyl acetate into propylene glycol monomethyl ether acetate, the proposed reactive-extractive distillation system enables the recovery of methyl acetate. Compared to other configurations that also retain the chemical identities of the separated components, this approach reduces total annual cost by 17.6 % and 10.8 %, and improves net revenue by 11.8 % and 11.5 % versus triple-column extractive distillation and extractive distillation with pre-separation, respectively. Thus, for separating methanol, methyl acetate, and ethyl acetate without altering their chemical form, this system is a more favorable option.