Techno-economic assessment of dimethyl carbonate production based on carbon capture and utilization and power-to-fuel technology

The present study focuses on the process modeling and techno-economic assessment of four dimethyl carbonate production concepts based on the transesterification route. The scenarios differ on two aspects. Firstly, they differ regarding the use of fossil-derived methanol from the market or its synthesis on-site using externally procured green hydrogen. Secondly, they differ regarding the utilization of carbon dioxide procured from a pipeline network or captured from a coal-fired power plant, assuming that the dimethyl carbonate facility is integrated into it. Process models of the feedstock conditioning, methanol synthesis and dimethyl carbonate production plant sections are developed and optimized in Aspen Plus to maximize the yield of produced dimethyl carbonate. The dimethyl carbonate/carbon dioxide ratio of the concepts ranges from 1.38 kg/kg to 0.53 kg/kg, when methanol is purchased or produced on-site, respectively. Moreover, if grid electricity and natural gas are used for covering the electricity and heating needs of the plant, gate-to-gate carbon dioxide emissions are negative (as low as -105.48 kt/a). Under the base-case evaluation, the dimethyl carbonate minimum selling price of the different scenarios ranges from 634 to 1263 euro/t. Due to the high cost of green hydrogen, the scenarios involving on-site methanol synthesis have substantially inferior economic performance and are currently economically infeasible. However, a potential green hydrogen price reduction to 1233 euro/t can make them profitable, with dimethyl carbonate minimum selling prices of 659-707 euro/t, which are below the current market price of 849 euro/t.