Feasibility, Limit, and Suitable Reaction Conditions for the Production of Alcohols and Hydrocarbons from CO and CO2 through Hydrogenation, a Thermodynamic Consideration

The conversion of CO and CO2 into valuable liquid fuels and value-added chemicals has attracted intense interest from engineers and researchers in recent years owing to its potential in the exploitation of renewable energy resources and the remission of greenhouse gases to counteract the present serious threat of global warming. Although great progress has been made in the research and development of appropriate catalysts for the CO/CO2 hydrogenation to alcohols and light olefins, it is often rather puzzling whether the reactions are approaching the equilibrium or the yield of target products can still be greatly enhanced through modifying the catalyst and/or modulating the operation conditions. Herein, a thermodynamic consideration is made to systematically evaluate the feasibility, limit, and suitable reaction conditions for the production of alcohols and hydrocarbons from CO and CO2 through hydrogenation. The results indicate that the hydrogenation of CO/CO2 to alcohols, light olefins, and aromatics is thermodynamically viable under appropriate conditions. Although current CO/CO2 conversion processes may in general be restricted by the kinetic factors, great care should be taken to ensure that the pertinent reactions are conducted under the thermodynamically feasible conditions. These results help ascertain the suitable operation region for CO/CO2 hydrogenation as well as mark the margin and direction for the optimization of the present catalyst and process, which are surely beneficial for the development of efficient processes for producing fuel and chemicals from CO/CO2 hydrogenation.