Dimethyl ether (DME) is a renewable liquid or gaseous transport fuel of non-biological origin (RNFBO) that can be produced from captured CO2 using Power-to-X technologies. DME can be used as a diesel fuel replacement with minor engine modifications and has the potential to reduce air pollution compared to conventional petrodiesel. The EU Renewable Energy Directive (RED II) requires that the production of CO2-derived DME and its use as a fuel result in carbon emissions at least 70% lower than the petrodiesel alternative in order to be eligible for support. This study compares the carbon footprint of producing and using DME as a transport fuel via the SEDMES process with the carbon footprint of producing and using fossil-based petrodiesel. The results show that the cradle-to-grave carbon footprint of using DME as a transport fuel is 77% lower than for petrodiesel when offshore wind power is used for hydrogen synthesis and DME production. If renewable energy is also used for CO2 capture and waste heat is used for DME production and purification, the DME carbon footprint has the potential to be over 90% lower than that of the fossil-fuel comparator.
Image Source: Front. Sustain., 29 November 2022
Sec. Sustainable Chemical Process Design