Design and optimization of an acetic acid recovery system via extraction–distillation using an isopropyl acetate + isopropanol mixed solvent

Abstract

Azeotropic distillation incorporating liquid–liquid extraction was used for the dehydration of dilute acetic acid (HAc) solution. A hybrid extraction–distillation process was designed and simulated using isopropyl acetate + isopropanol (IPA-01 + IPA-02) as a solvent (an extractant and an entrainer), and the same processes using pure isopropyl acetate (100IPA-01) and pure ethyl acetate were also simulated. An optimal composition of the solvent was determined to be the mixture of 82 wt% IPA-01 and 18 wt% IPA-02 (82IPA-01/18IPA-02). The result shows that the operating costs and capital costs of the process using IPA-01 + IPA-02 solvent are lower than that using 100IPA-01 solvent. The optimal design of the hybrid extraction–distillation process making use of 82IPA-01/18IPA-02 as a solvent brought a reduction of the total annual cost by about 35.36% and 47.89% compared to those of the 100IPA-01 and ethyl acetate solvents, respectively.

Keywords:

• Acetic acid dehydration
• azeotropic distillation
• extraction
• total annual cost