Performance of p-Toluenesulfonic Acid–Based Deep Eutectic Solvent in Denitrogenation: Computational Screening and Experimental Validation

Abstract

Deep eutectic solvents (DESs) are green solvents developed as an alternative to conventional organic solvents and ionic liquids to extract nitrogen compounds from fuel oil. DESs based on p-toluenesulfonic acid (PTSA) are a new solvent class still under investigation for extraction/separation. This study investigated a new DES formed from a combination of tetrabutylphosphonium bromide (TBPBr) and PTSA at a 1:1 molar ratio. Two sets of ternary liquid–liquid equilibrium experiments were performed with different feed concentrations of nitrogen compounds ranging up to 20 mol% in gasoline and diesel model fuel oils. More than 99% of quinoline was extracted from heptane and pentadecane using the DES, leaving the minutest amount of the contaminant. Selectivity was up to 11,000 for the heptane system and up to 24,000 for the pentadecane system at room temperature. The raffinate phase’s proton nuclear magnetic resonance (1H-NMR) spectroscopy and GC analysis identified a significantly small amount of quinoline. The selectivity toward quinoline was significantly high at low solute concentrations. The root-mean-square deviation between experimental data and the non-random two-liquid (NRTL) model was 1.12% and 0.31% with heptane and pentadecane, respectively. The results showed that the TBPBr/PTSADES is considerably efficient in eliminating nitrogen compounds from fuel oil.

Separation of Benzene and Cyclohexane Using Eutectic Solvents with Aromatic Structure

“…It can be seen that the hydrogen bonding occurred between PTSA and TBPB instead of between PTSA and H 2 O. Similar phenomena of disappearance of the SO 3 peak to form a bond for the components of ES were also previously [62,63] reported in PTSA-based ESs, e.g., PTSA:tetrabutylphosphonium chloride (1:1), PTSA:tetrabutylammonium chloride (1:1), and PTSA:ChCl (1:1). Hydrogen bond formation between BTBACl and m-cresol is the driving force behind the synthesis of ES.…”

Alpha-glucosidase inhibitory activities of astilbin contained in Bauhinia strychnifolia Craib. stems: an investigation by in silico and in vitro studies

“…As indicated in Table 6 , COSMOquick was used to determine the sigma profile of molecules, after which the solubility properties of molecules in the solvent was analyzed. Hydrogen bond donor, nonpolar, and hydrogen bond acceptor regions make up the sigma profile [ 42 ]. The range between 0.008 e/A 2 and + 0.008 e/A 2 represents London dispersion forces.…”

Experimental and computational studies on isolation of cardanol from cashew nut shell liquid using diethanolamine‐based deep eutectic solvent at different molar ratios

“…Therefore, a peak in the sigma profile's positive electron density zone and a negative potential in the sigma potential's negative electron density region will both be indicators of high electron density. The sigma potential values can be used to identify how two molecules interact, with greater positive values indicating a stronger repulsive relationship and larger negative values indicating a more attraction interaction 91 . Figure 12 shows that prepared DESs in all molar ratios had similar trends in sigma potentials.…”

“…The sigma potential values can be used to identify how two molecules interact, with greater positive values indicating a stronger repulsive relationship and larger negative values indicating a more attraction interaction. 91 Figure 12 shows that prepared DESs in all molar ratios had similar trends in sigma potentials. The negative sigma potential values were found in both the HBA and HBD regions, indicating that the chosen DES system is a good polyphenol extraction solvent.…”