Deep eutectic solvents and conventional solvents as VOC absorbents for biogas upgrading: A comparative study

• Biogas upgrading process based on hydrophobic DESs and conventional solvents. Hydrophobic performed better than solvents in VOCs trapping. Negative value of ?G underlined that all are favorably solubilized absorbents. The physical absorption nature benefits recycling. We currently witnessing an increase biogas production the context fossil fuel decline future circular economy. However, raw contains undesirable compounds such as hydrogen sulfide, volatile organic (VOCs) carbon dioxide should be removed to upgrade biomethane. Absorption is effective method capture from biogas. In this work, we evaluated compared efficiency deep eutectic (DESs) fatty acids absorbents for three major found impurities (toluene, limonene octamethylcyclotetrasiloxane). vapor–liquid partition coefficient (K) studied were determined using static headspace-gas chromatography. effect temperature water content was assessed. Results show a decrease K water, being most with up 20000-fold lower case limonene. Interestingly, lowering allows reach close DESs. values (from ?6.95 ?22.89 kJ?mol ?1 ) obtained showing Obtained negative ?H ?34.86 ?51.17 indicate dissolution exothermic process. For absorbent |?H| VOC always higher |T?S|, enthalpically driven results efficient can achieved by proposed solvent also providing easy recycling, recovering