CO₂ conversion to syngas via reverse water-gas shift selective reactor: process design and analysis based on data-driven correlation

The reverse water-gas shift reaction is a promising route for converting carbon dioxide into carbon monoxide to make syngas fuels when combined with a source of hydrogen. This is an attractive option for removing or re-using carbon dioxide which is commonly emitted to the atmosphere. The design of such systems based on the reverse water-gas shift reaction have typically assumed the reaction operated at equilibrium or minimized the Gibbs free energy to determine the reactor yield and production rates. These existing studies suggest that high temperatures (800-1,000 °C) are essential for the effective production of carbon monoxide. However, there has also been great progress in the field of catalysts with the development of material which can produce carbon monoxide even at lower temperatures. This study aims to investigate the potential for using modern catalysts through a data-driven approach where correlations are used to predict the conversion trends of modern catalysts. The conversion model is then incorporated into process simulation, where the reverse water-gas shift process integrated with syngas purification technologies is investigated. It must be noted that most catalyst studies utilize a high ratio of hydrogen to carbon dioxide feed, but lower feed ratios must also be tested to produce desirable syngas ratios. Simulation results show that higher reactor temperatures generally lead to lower energy consumption, with lower separation energy required. However, it is shown that using cryogenic distillation similar energy efficiencies can be obtained while operating at lower reactor temperatures.