Carbon footprint of Power-to-X derived dimethyl ether using the sorption enhanced DME synthesis process

Abstract

Dimethyl ether (DME) could have a promising future as a sustainable diesel fuel replacement as it requires only relatively minor engine modifications. It can be produced from renewable H 2 and captured CO 2 using Power-to-X technologies. To gain support through the EU Renewable Energy Directive, the production and use of CO 2 -derived DME as a fuel needs to produce emission savings of at least 70% over the petrodiesel alternative. This study assesses the carbon footprint of producing DME via the sorption-enhanced DME synthesis (SEDMES) process and using it as a transport fuel, compared to producing and using fossil-based petrodiesel. The cradle-to-grave (well-to-wheel) carbon footprint of using DME as a transport fuel is found to be 77% lower than for petrodiesel, if offshore wind power is used for H 2 synthesis and DME production. If renewable energy is also used for CO 2 capture and waste heat is used for the DME production and purification steps, the DME carbon footprint has the potential to be over 90% lower than that of the fossil-fuel comparator.