Methanol economy and net zero emissions: critical analysis of catalytic processes, reactors and technologies

Abstract

The overuse of fossil fuels has led to the disruption of balance of the carbon cycle: the transportation and electricity generation sectors are the greatest contributors. Among other greenhouse gases, CO2 is the leading contributor to global warming, and catalytic transformation of CO2 into fuels and chemicals by utilizing renewable energy is regarded as the most promising way towards alleviating CO2 emissions wherein green hydrogen will play a critical role. Methanol is a crucial compound for our modern economy as it is employed as a building block for synthesizing several chemical intermediates, hydrocarbons, energy storage media, solvents, and fuels. Many scientists predict that methanol will become a central participant in the worldwide economy landscape soon. Therefore, it is very necessary to improve and optimize the overall methanol synthesis process to cut down its cost to the level of fossil fuels. The methanol synthesis technology can be divided into three sub-processes, i.e., feed gas production including power plant emissions, advanced catalysis and reactor technology. The current paper has reviewed all three aspects and also discussed the kinetics and reaction mechanisms of methanol synthesis. Further research initiatives should focus on innovative CO2 capture technologies and CO2 refinery to mitigate climate change, dry reforming and biogas generation processes, membrane reactor technologies, and finally, adoption of renewable energy for (green) hydrogen production to reduce the cost of methanol and advance these innovative scientific concepts to promote societal acceptance. It will be in tune with the net-(carbon)-zero goal which has been advocated by the Paris Agreement of 2015 and recently echoed in the Leaders’ Summit on Climate in April 2021.