Investigation of energy-efficient and sustainable reactive/pressure-swing distillation processes to recover tetrahydrofuran and ethanol from the industrial effluent

Abstract In this work, we report an approach for conceptual design and optimization of an energy-saving and sustainable reactive/pressure-swing distillation process to separate a ternary mixture tetrahydrofuran/ethanol/water with three azeotropes. The novel reactive/pressure-swing distillation schemes with two different separation sequences are proposed via the thermodynamic feasibility analysis. In these processes, the component of water in the ternary system is firstly removed by adding a reactant in the reactive distillation column and the remaining binary azeotropic mixture is then separated via the pressure-swing distillation. An improved genetic algorithm is employed for optimizing the proposed processes. Furthermore, the heat integration approach is adopted to further reduce the energy consumption. The evaluations illustrate that total annual cost and CO2 emissions of the proposed processes based on the proposed reactive/pressure-swing distillation with (and without) heat integration schemes could be significantly reduced by 50.16% (54.80%) and 53.00% (59.11%), and total net revenue could be decently increased with 12.19% (12.40%), compared with the existing triple-column pressure-swing distillation process. In addition, the thermodynamic efficiency of the existing process is significantly improved via the proposed reactive distillation processes.