Environmental and economic assessment of global and German production locations for CO2-based methanol and naphtha

The utilization of CO2 in combination with renewable energy and water is a promising alternative for the use of fossil hydrocarbons in the chemical industry. In countries like Germany, the required amounts of renewable energy for a large-scale production will most probably exceed their availability. To gain more information about the environmental impacts and economic parameters of a potential import of CO2-based chemicals, 19 representative international production locations were identified considering energy, CO2, and water availability and compared to 2 locations in Germany. Life cycle and economic assessments were done for all locations for CO2-based methanol and naphtha. The results show that location-differences determine environmental impacts and economic parameters with a tendency of wind-based locations outperforming those using photovoltaic cells. Comparing both chemicals, methanol shows better results in every category with the examined German locations showing promising results. While a decrease of the climate footprint can be reached for both chemicals at all locations in relation to the conventional alternatives, they also show a trade-off between the climate footprint and at least two other environmental impacts which raises the risk of problem shifting. The economic results imply that for some locations a competetive production is in range in the medium term even without changed policies. At the same time, the inclusion of chemicals into carbon pricing schemes may not be sufficient for every production location, since the calculated break-even carbon prices for methanol range from 284 € per t CO2 to 1.619 € per t CO2 in the status quo and from 11 € per t CO2 to 735 € per t CO2 in 2030. The high variances of the environmental and economic results indicate the necessity for a careful selection process of production locations. Importantly, desalination of water did not significantly raise the environmental impacts or production costs. Therefore, it might be promising to develop production plants in regions with very good conditions for renewable energy production while planning to use saline water to avoid additional pressure on water systems.