Techno-economic analysis of alternative processes for alcohol-assisted methanol synthesis from carbon dioxide and hydrogen

The novel methanol production from carbon dioxide (CO2) and hydrogen (H2) called alcohol-assisted process is simulated. Although the alcohol-assisted process allows the reduction in operating temperature and pressure, the subsequent product purification is complicated. Comparative studies between the conventional CO2 hydrogenation and the alcohol-assisted processes are carried out (case I-V). The alcohol-assisted processes present the opportunity of increasing the CO2 conversion per-pass and reducing 25% of the hydrogen consumption, the barriers in the conventional process. However, the product purifications remain challenging due to the azeotrope of methanol and by-products. Energy consumptions decrease in the feed and reaction sections of the alcohol-assisted processes but significant increase in the product purifications. The formation of by-products and the sequence of purification units affect process performance and economics. The obtained results indicate that the product purification and the catalyst development to increase methanol selectivity and produce an easy-separated by-product play key roles in the enhancement of the process feasibility. (c) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Superscript/Subscript Available

Automated summary

Alcohol-assisted methanol production process increases CO2 conversion rate and reduces hydrogen consumption effectively, but faces challenges in product purification; energy consumption decreases in feed and reaction sections, but significantly increases in product purification.