Life-cycle assessment of oil recovery using dimethyl ether produced from green hydrogen and captured CO2

Hydrocarbon fuels are widely recognized as significant contributors to climate change and the rising levels of CO2 in the atmosphere. As a result, it is crucial to reduce the net carbon intensity of energy derived from these fuels. This study explores the feasibility of using dimethyl ether (DME), produced through the hydrogenation of CO2, as a low-carbon method for generating electricity from hydrocarbon fuels. The proposed approach involves capturing the emitted CO2 during combustion and utilizing it to produce the necessary DME in a closed cycle. It is shown that for a mature reservoir in the Middle East, this method can mitigate approximately 75% of the CO2 emissions released from burning the produced oil. By incorporating zero-carbon electricity throughout the process, the total abatement of CO2 can reach 85%. Furthermore, the study highlights the importance of improving the DME utilization factor (bbl-oil/tDME). By optimizing this factor, high abatement rates can be achieved. However, it is important to note that implementing this method comes with a high exergetic cost. During a certain period in the field’s lifetime, the invested energy exceeds the energy produced. The stages with the highest exergy consumption are CO2 capture and hydrogen production.