Methanol synthesis from CO2 via hydrogenation route: Thermodynamics and process development with techno-economic feasibility analysis

The present study investigated the thermodynamic and economic feasibility of methanol synthesis reactions from CO2 and H2. Three reactions, namely CO2 hydrogenation to methanol, reverse-water-gas-shift (RWGS) and methanol decomposition reaction, were considered. The effect of temperature, pressure and H2/CO2 mole ratio on CO2 conversion and methanol selectivity was examined explicitly. The simulation results were compared with experimental data. A conceptual process design for methanol synthesis from CO2 was developed using an Aspen Plus process simulator. At 250 °C and 50 bar, the analysis shows about 73% CO2 conversion and 99.7% CH3OH selectivity for a recycling ratio of 0.9. A techno-economic feasibility study was performed to understand the influence of feed and product cost, recycling ratio and plant throughput, on plant profit margins. The study revealed that the proposed process might be economically viable if the H2 price is lower than 1,500 $/ton and/or with a methanol production capacity of more than 250 tons/day.