Intensification and analysis of extractive distillation processes with preconcentration for separating ethyl acetate, isopropanol and water azeotropic mixtures

Ethyl acetate (EAC) and isopropanol (IPOH) are important organic chemical raw materials. During the production of ampicillin sodium, there are a large amount of waste water containing EAC and IPOH. In order to separate the dilute solution containing EAC, IPOH, both a four-column extractive distillation process with pre concentration distillation column (PDC) and a three-column extractive distillation process of combining the pre-concentrated column with the extractant recovery column (ERC) are presented. In addition, three intensified processes with the application of heat integration and heat pump are proposed. The feasibility of the proposed processes is evaluated from four aspect: economy, energy consumption, environment, exergy analysis. The results show that these five processes have a good effect of energy saving and cost saving. Especially, the vapor recompressed heat pump assisted CTE process (HP-CTE) process, which is the most energy saving scheme, can reduce 37.80% of total annual cost, 55.43% of energy consumption, 54.46% of CO2 emission, 54.85% of SO2 emission, 54.82% of NOX emission, and 53.17% of exergy destruction, respectively, compared with the proposed four-column process.

Automated summary

Ethyl acetate and isopropanol are efficiently separated from a dilute solution during the production of ampicillin sodium through extractive distillation processes and intensified processes with heat integration and heat pump. These processes have shown significant energy and cost saving effects.