Study on the separation of methyl-ethyl-ketone / isopropanol / water ternary mixture by energy-efficient extractive distillation processes

The separation of ternary mixtures of methyl-ethyl-ketone (MEK)/isopropanol (IPA)/water, which are produced through chemical processes, is an imperative task aimed at reducing energy expenditures and mitigating environmental contamination. In the industry, Ethylene glycol (EG) and dimethyl sulfoxide (DMSO) are commonly employed as extractants. The selection of EG as the extractant was based on an investigation into the impact of relative volatility. Three distinct processes, namely conventional extractive distillation (CED), side-stream extractive distillation (SED), and heat pump extractive distillation (HPED), were evaluated by total annual cost (TAC), total energy consumption (TEC) and carbon dioxide emissions (CO2 emissions). The results demonstrate that both the enhanced SED and HPED processes effectively decrease energy consumption. Specifically, the TEC for the SED process exhibits a reduction of 15.36% compared to the CED process, resulting in a TAC saving of 9.06% and a decrease in CO2 emissions by 12.37%. Similarly, the HPED process surpasses the CED process by achieving a TAC saving of 15.41% and a CO2 emissions reduction of 22.61%. Consequently, this research presents a novel approach for the separation of MEK/IPA/water, offering significant practical implications. •The optimal process is studied for energy saving and economic performance.•Three processes are studied to separate ternary azeotropic mixture.•All processes are optimized with total annual cost as the economic indicator.