Ionic Liquids for Biogas Upgrading: Molecular Insights and Process Intensification

Biomethane is considered a promising sustainable renewable energy source to meet the growing global energy demand. Therefore, to obtain high-quality biogas, a green and efficient process has been proposed to remove all these impurities during biogas upgrading. The appropriate ionic liquid (IL) was selected using quantum-chemical and toxicity analysis methods. The process was modeled and simulated, and the results showed that the IL removal process performed well, with CH4 purity and CO2 removal rate reaching 99.60 and 99.30%, respectively. The impact of various operating variables on process performance was investigated through a sensitivity analysis, providing researchers with essential data for informed decision-making. Compared to traditional solvent simulation processes, IL processes offer higher recovery rates, lower loss ratios, and more stable properties, resulting in significant energy savings. The results indicate that ILs as absorbents are a good choice for upgrading biogas processes.