Distillation-Adsorption Hybrid Processes to Separate Binary Liquid Mixtures with Homogeneous Azeotrope

Isopropanol (IPA) is a major solvent in the semiconductor industry. During production, IPA is often obtained as an aqueous mixture that forms an azeotrope. Azeotropic distillation, commonly used to separate the azeotrope, has high energy requirements. The current work explores hybrid processes pairing distillation with temperature swing adsorption (TSA) (with activated carbon) or with pressure vacuum swing adsorption (PVSA) (with 3A zeolite). The feed was 10mol% IPA and target purity was 99.9999 mole%. Optimized distillation/adsorption hybrid schemes were compared to optimized azeotropic distillation. On the basis of total yearly costs, distillation-PVSA was found to be the most economical scheme followed by azeotropic distillation and then distillation-TSA.