Economic and environmental assessment of heat pump integration in thermally coupled hybrid separation

•Replacement of conventional energy source by electricity driven compressor.•Process design excluding additional separation equipment.•Direct by-product separation in the RDS process.•Non-equilibrium stage model of thermally coupled hybrid separation.•Comparison of environmental footprint of designed processes. Process intensification of thermally coupled hybrid separation is presented in this paper. Production of ethyl acetate via reactive distillation with a stripper column (RDS) is employed as a basic thermally coupled hybrid separation process. The reactive distillation column has a condenser and a reboiler and the stripper column has a reboiler only. In addition, no auxiliary separation equipment such as a decanter or a regeneration column is required. On the other hand, despite the RDS process being highly integrated, it has several bottlenecks; large equipment (columns and heat exchangers); high external energy requirements for both cooling and heating. Also, it is known for large recycles (liquid and vapor). Therefore, to further intensify the RDS process, including a heat pump is proposed. A mechanical vapor recompression heat pump (MVRHP) is employed to reduce external cooling and heating requirements; to replace conventional energy source (heating steam) by an external source (compressor driven by electricity from renewable sources). Two different alternatives of heat pump-assisted RDS processes are designed. Performance and effectivity of the designed alternatives are compared with original RDS process using several indicators, including energy aspects, process economics, and environmental footprint. Results show that MVRHP can be deployed in the RDS process effectively reducing energy requirements while no equipment size changes (columns) are needed. Heat pump-assisted RDS processes show better economic performance despite higher capital costs. More importantly, when MVRHP is introduced in the RDS process, environmental footprint in form of CO2 emissions is decreased significantly. Finally, heat pump application in thermally coupled hybrid separation is highly recommended despite higher capital costs. Lower amount of emissions and utilization of electricity from renewable sources being the main benefits.