(372b) Hybrid Heat-Integrated Design Alternatives of Dimethyl Carbonate Reactive Distillation

Enhanced energy-efficient design alternatives for dimethyl carbonate production by combining various heat integration methods of reactive and pressure-swing distillation (PSD) columns were proposed. The design alternatives of hybrid heat-integrated sequences were based on internal and external heat integration between the columns with a vapor recompression heat pump (VRHP). The conventional PSD sequence with a reactive distillation column and the proposed hybrid heat integration sequences were compared subject to a constraint of high product purity of 99.5%. The combined sequence of internal and external heat integration resulted a cost saving of 30.28% by eliminating the low-pressure (LP) column reboiler. The external heat integration combined with VRHP fully eliminated the heat duty of the high-pressure (HP) column condenser and the LP column reboiler, which showed 38.33% energy savings and a 37.5% reduction in CO2 emissions. The hybrid sequences with external heat integration showed better performance in terms of energy, economic efficiency and CO2 emissions than the internal heat integration with VRHP, since the reflux flow rate of the HP column and the reboil flow rate of the LP column were significantly reduced.