Efficient in-situ water adsorption for direct DME synthesis: Robust computational modeling and multi-objective optimization

Abstract

The concept of in-situ water elimination in the novel integrated multifunctional reactor (MR) with the aim of increasing Dimethyl Ether (DME) production via direct method synthesis is investigated in the present study. Introducing continuous regenerative 4 A zeolite adsorbent in the moving bed reactor with syngas feed stream is considered an impressive improvement over the conventional fixed sorption enhanced reactor. In the absence of water adsorption, the validation results exhibit that the offered comprehensive 1-D heterogeneous model equipped with Unilan isotherm has an excellent agreement with industrial data. Also, the simulation results illustrate that around 35% and 25% elevation in the DME production rate and selectivity is obtained via effective water removal in the MR compared to the non-adsorbent configuration. Enjoying in-situ water removal in the MR, synthesis gas conversion plus methanol production is significantly improved. The multi-objective optimization of MR recruiting powerful NSGA-II algorithm with the purpose of maximizing DME production rate and selectivity is accomplished. Among the three distinct decision-making approaches, Shannon's Entropy presents better results according to the deviation index parameter. Operating at optimal conditions in the MR enhance around 201 ton/day and 31% in the DME production and selectivity, respectively, rather than the conventional reactor. Moreover, curbing CO2 emission nearby 122 ton/day leads to consider the MR as an environmentally friendly reactor.