Evaluating the Performance of Deep Eutectic Solvents for Use in Extractive Denitrification of Liquid Fuels by the Conductor-like Screening Model for Real Solvents

A total of 94 deep eutectic solvents (DESs) based on different combinations of salt cation, anion, hydrogen-bond donor (HBD) and salt:HBD molar ratio are screened via the conductor-like screening model for real solvents for potential use in the extractive denitrification of diesel. Five nonbasic and six basic nitrogen compounds were included in this study. The activity coefficient at infinite dilution, gamma(infinity), of each nitrogen compound in the DESs was predicted; and the values are used to screen the DESs on the basis of selectivity, capacity, and performance index at infinite dilution (S-infinity, C-infinity, and PI). The extraction of nitrogen compounds using DES is driven by hydrogen-bonding interaction. It was found that nonbasic compounds report higher S-infinity and C-infinity than basic compounds. Ammonium-based DESs give higher S-infinity but phosphonium-based DESs report higher C-infinity. DESs combined with Cl anion give higher S8, but those with Br anion report higher C-infinity. DESs with alcohol- and amide-based HBDs give higher S-infinity but HBDs with carboxylic acid group report high C-infinity. Molar ratio has little effect toward S-infinity and C-infinity. DESs with high values of S-infinity generally have high PI.