Novel process technologies for conversion of carbon dioxide from industrial flue gas streams into methanol

This research aims to develop efficient process technologies that are capable of converting/utilising CO2 streams into energy-rich liquid products (fuels). This would result in better solutions with near-zero-carbon-emissions level. From an energetic and economic point of view, methanol synthesis from CO2 is a competitive alternate to methanol production from biomass. Our work considers the CO2 balance for the technologies proposed, taking into account all CO2 flows from/to the environment. Flue gas CO2 streams released from electric power stations, steel industry, petroleum industry, and cement industry are good candidates for the developed technologies. Three new processes are developed and modelled for converting CO2 streams into liquid methanol. The total cost of equipment and utility for all process scenarios are evaluated and compared. The energy targets as well as the CO2 emissions (balance) are determined. Heat integration is performed on the best selected process technology. The case study employed for the present work is a power station plant burning natural gas for electricity production with a capacity of 112 MW, releasing 328 t/h flue gases to the atmosphere, of which CO2 gas accounts for 14%; hydrogen required for CO2 conversion comes from the chlor-alkali industry. The optimum process technology reached in this contribution results in methanol production of 0.625 t-per-tonne of CO2 waste gas supply, leading to an annual production of 222,507 tons methanol with a profit of 56.55 M$/y. Thus, the CO2 release to the environment is cut by about 62%.