Investigation about energy-saving for the isobutyl acetate synthesis in a reactive divided-wall column via vapor recompression heat pump

Abstract

In this work, the design that integrated vapor recompression heat pump into reactive divided-wall column (RDWC-HP) is proposed for the synthesis of isobutyl acetate. Due to the large differential temperature between the overhead vapor stream and bottom stream in the reactive distillation column, five different RDWC-HP processes are designed, in which the compressed stream provides heat in the single side reboiler or double side reboiler or interreboiler. The total annual cost, energy consumption and CO2 emission are the rules to evaluate all processes. Compared with the corresponding reactive divided-wall column (RDWC) process, the five RDWC-HP processes show better performance as aspect of energy consumption and total annual cost. The result indicates the RDWC-HP scheme that the compressed stream exchanges heat with the bottom reboilers of reactive distillation column and separation column saves 26.26 % of the energy consumption, 87.05 % of the CO2 emission and 20.68 % of the total annual cost with a payback period of 5 years, when compared with the corresponding RDWC process.