Application of an Energy-Efficient Process with Reactive Coupling Pressure-Swing Distillation for Recycling Organic Materials from Wastewater

Abstract

A sustainable reactive coupling pressure-swing distillation process is investigated to separate the acetonitrile/isopropanol/water ternary mixture. To solve the problem of high energy consumption in this process, the application of heat integration and heat pump technologies on the basis of the reactive coupling pressure-swing distillation process are explored to achieve further energy saving. The results showed that the processes with heat pump have the better potential for energy reduction. Comparative analysis from the aspects of exergy, energy consumption, cost, and gas emission are conducted to evaluate the thermodynamic efficiency and economic and environmental improvement potential of the proposed processes. The reactive coupling pressure-swing distillation process in combination with a single heat pump, RPSDL-SHP, exhibits the best economic performance and 48.51% reduction in the total annual cost and 70.04% energy saving in comparison with the conventional process. The total exergy efficiency of RPSDL-SHP is up to 97.92%, which means that application of heat pump is feasible to save energy, reduce the cost of the process, and enhance exergy efficiency.

Economic and Environmental Evaluation of Heat-Integrated Pressure-Swing Distillation by Multiobjective Optimization

“…Wang et al studied the separation of water/acetonitrile/isopropanol mixture via PSD by heat pump technology and saved the TAC by 57%. Similarly, the reactive-PSD for separating water/acetonitrile/isopropanol was studied by Li et al From the analysis of the above studies and the features of the PSD itself, the crucial issues in the process design are concluded: Whether or not the separation of the targeted azeotrope by PSD is feasible? How to assess the feasible separation sequences?…”