Economic assessment of CO2-based methane, methanol and polyoxymethylene production

Carbon dioxide (CO2) could be used as carbon source for chemical production. Compared with the environmental assessment, the economic assessment is related with several open questions. Particularly, it still remains unclear when and under which conditions the CO2-based production might become profitable. Besides production costs, the cost drivers and options to stimulate the CO2-based production of methane, methanol and polyoxymethylene (POM) in Germany are analyzed. In order to consider the CO2-based production in a realistic way, various options of operation and give an outlook for a potentially cost-effective development in the next decades are analyzed. The approach is based on life cycle costing. Raw biogas, waste gases of a cement plant, and flue gases of a waste incineration plant are considered as CO2-sources. The energy needed to convert CO2 into hydrocarbons via electrolysis is assumed to be supplied by wind power from negative residual load, a dedicated wind park, or by power from the grid based on a low-price deal at the electricity exchange. Economic data originates from both industrial processes and process simulations. The results indicate that CO2-based production technologies are not competitive with conventional production methods under present conditions. This is mainly due to high electricity generation costs, high investment costs for electrolysis, and regulative factors like the German Renewable Energy Act (EEG) in case of energy supply from grid. A CO2-based polymer would closer to economic competitiveness than CO2-based platform chemicals. While the decrease in production costs of CO2-based chemicals may be limited in the next decades, a modification of relevant regulative factors could potentially promote an earlier commercialization. Relatively low prices for renewable energy supply may lead to commercialization options of CO2-based products until 2030.