(660b) Design and Optimization of an Acetic Acid Recovery System Via Extraction-Distillation Using an Isopropyl Acetate+Isopropanol Mixed Solvent

Azeotropic distillation incorporating liquid-liquid extraction was used for the dehydration of dilute HAc solution. A hybrid extraction-distillation process was designed and simulated for isopropyl acetate+isopropanol (IPA-01+IPA-02), and the same process using pure isopropyl acetate (100IPA-01) as a solvent was also simulated as a comparison. The effect of IPA-02 content in the solvent on the whole process was studied and the best solvent composition was determined. 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 hybrid extraction-distillation process design was carried out using 82IPA-01/18IPA-02 and 100IPA-01 as solvents, respectively. The optimal design of the hybrid extraction-distillation process was achieved by the minimization of total annual cost (TAC) using Aspen plus. 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 35.7% compared to that of the IPA-01 solvent.