Carbon dioxide utilization in methanol synthesis plant: process modeling

The conversion of CO2 to methanol holds great promise, as it offers a pathway to reduce CO2 level in the atmosphere and also produce valuable components. In this study, a typical methanol synthesis plant for CO2 conversion was numerically modeled. Effect of fresh feed to plant parameters (i.e., pressure and CO2 concentration) as well as the influence of recycle ratio on the reactor performance was investigated. Hence, all essential equipment, including compressor, mixer, heat exchanger, reactor, and liquid-vapor separator were considered in the model. Then, at the best operating conditions, thermal behavior and components distribution along the length and radius of the reactor were predicted. Finally, the effect of inert gases was investigated in the methanol production process and the results were compared with the conventional route (CR), which uses natural gas for methanol synthesis. The results revealed that in the absence of inert gases and by employing a recycle stream in the process, CO2 hydrogenation leads to 13 ton/day production of methanol more than CR. While in the feedstock containing 20% inert gases, which is closer to the realistic case, methanol production rate is 45 ton/day lower than CR. These findings prospect a promising approach for the production of green methanol from carbon dioxide and hydrogen.

Automated summary

A numerical model was used to study the conversion of CO2 to methanol in a typical plant, showing that employing a recycle stream can increase methanol production, but the presence of inert gases in the feedstock can significantly reduce methanol yield compared to the conventional route.