A novel energy-efficient process of converting CO2 to dimethyl ether with techno-economic and environmental evaluation

This work aims at discovering the potential of CO2 reduction by implementing techniques of process intensification in the production processes of green alternative fuel, dimethyl ether (DME), from CO2 and renewable hydrogen (H-2) with both one-step and two-step configurations. A novel intensified process using the two-step configuration (named as TSHI), which converts CO2 to methanol followed by the dehydration of methanol to DME, is proposed in this study. Developed based on the validated thermodynamic representation and the reaction kinetics expression, TSHI shows the greatest potential of CO2 reduction - 1.704 ton CO2/ton DME - among the five discussed process scenarios. TSHI's energy consumption per unit weight of DME is compared with reported case in the literature, which also uses CO2 and renewable H-2 as feedstock in a two-step configuration, and the result has shown an energy saving amount of 23%. Though TSHI exhibits high capability of reducing CO2 amount in the atmosphere, the result of techno-economic analysis showed that there are still rooms for further improvements to produce green alternative fuel cost-effectively. (C) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.