Abstract
Renewable-to-X products such as methanol (MeOH) and dimethyl ether (DME) offer scalable, carbon-neutral options for decentralized chemical production. Microreactors, with superior heat and mass transfer, provide more controllable reaction environments. This improved control enhances selectivity and conversion, making microreactors particularly well suited for intensifying CO2/CO hydrogenation within a Power to X framework for synthetic products. However, an assessment of MeOH and DME synthesis routes under microreactor operation is still lacking. To address this gap, a microreactor-scale model was developed where two reactor configurations were analyzed: i) parallel configuration, in which MeOH synthesis and subsequent dehydration to DME take place in the same reactor, and ii) series configuration, in which MeOH synthesis is carried out in the first reactor, followed by MeOH dehydration to DME in a second reactor. To capture realistic process behavior, the simulations incorporated non-isothermal, non-isobaric operation and fugacity-based reaction rates. The comparison reveals that reaction decoupling in the series configuration enables higher overall conversion of MeOH to DME, while the parallel route is constrained by strong kinetic and thermal coupling between hydrogenation, dehydration, and water formation. Despite requiring fewer unit operations, the parallel route yields mixed MeOH-DME product streams, whereas the series pathway favors higher DME productivity. The results highlight a fundamental trade-off between process intensification and conversion efficiency in microreactor-based Renewable-to-X systems.