Extraction of Thiophene, Pyridine, and Toluene from n-Decane as a Diesel Model Using Betaine-Based Natural Deep Eutectic Solvents

Abstract

In an attempt to develop an alternative process that meets the criteria of "green" and economically sound technology in fuel purification, simultaneous extractive desulfurization, denitrification, and dearomatization using natural deep eutectic solvents (NADESs) were investigated. A NADES composed of betaine (Bet) as a hydrogen bond acceptor (HBA) and levulinic acid (LevA) as a hydrogen bond donor (HBD) was investigated for its extraction capacity of thiophene, pyridine, and toluene from n-decane via liquid−liquid extraction. First, the HBA/HBD molar ratio was optimized based on the highest overall extraction efficiency, which was achieved for Bet/ LevA (1:7). Furthermore, the selected NADES was characterized by measuring its density, dynamic viscosity, and water content. Then, the solubility of each fuel impurity in the NADES was measured. Moreover, the liquid−liquid equilibrium (LLE) data of the pseudo-ternary systems {n-decane (1) + thiophene/pyridine/ toluene (2) + Bet/LevA (1:7) (3)} were determined at 298.15 K and 1.01 bar. The assumption of a pseudo-ternary system, which means that the NADES stays intact in one phase, was validated experimentally. The solute distribution ratios, selectivities, and the extraction efficiencies of each impurity at a 1:1 solvent-to-feed mass ratio were calculated from the experimental LLE data and compared to a benchmark solvent (i.e. sulfolane) and other ionic liquids and DESs reported in the literature. The LLE data were also correlated using the nonrandom two-liquid thermodynamic model. The regressed LLE data showed good agreement with the experimental data as the root-mean-square deviation was found to be ≤0.29%. Finally, it is clear that Bet/LevA (1:7) can be considered as a potential natural solvent for combined desulfurization, denitrification, and dearomatization processes.

Green Extraction of Volatile Fatty Acids from Fermented Wastewater Using Hydrophobic Deep Eutectic Solvents

“…The aqueous solutions were prepared as described in Section 2.2. The results in Figure 15 show that the pure component efficiency and the mixture efficiency of the VFAs are almost identical, suggesting that each acid occupies different void sites in the HDES-phase and does not compete with the others under the studied concentrations [36]. It can also be observed that the extraction efficiency was increasing with an increase in VFA chain length as follows: valeric acid (96.5%) > butyric acid (89.9%) > propionic acid (72.3%) > acetic acid (40.5%) with distribution coefficients of 𝛽 13.46, 𝛽 4.36, 𝛽 1.3 , 𝛽 0.36, respectively.…”

“…The equilibrium cell method [35][36][37] was adopted to measure the solubilities of the pairs: (acetic acid (1) in water or HDES (2)), (propionic acid (1) in water or HDES (2)), (butyric acid (1) in water or HDES (2)), (valeric acid (1) in water or HDES (2)), and the saturation of HDES with water at 298.2 K and 1.01 bar. In this method, 4 g of the mixtures was prepared in 8 mL glass vials.…”

Dearomatization Insights with Phosphonium-Based Deep Eutectic Solvent: Liquid–Liquid Equilibria Experiments and Predictions

“…22 Similar studies were performed for NADESs in the extraction of thiophene, pyridine, and toluene from n-decane. 23 The results showed an increase in distribution ratio, selectivity, and extraction efficiency (EE) with the order as follows: pyridine > thiophene > toluene. Rogosǐćand Kucǎn performed the extraction using choline chloride-based DES.…”

“…Lemaoui et al studied the simultaneous dearomatization, desulfurization, and denitrogenation of diesel fuels via liquid–liquid extraction . Similar studies were performed for NADESs in the extraction of thiophene, pyridine, and toluene from n -decane . The results showed an increase in distribution ratio, selectivity, and extraction efficiency (EE) with the order as follows: pyridine > thiophene > toluene.…”

Separation of Aromatics from a Cyclic-Aliphatic Hydrocarbon Using Ethylene Glycol and a Choline Chloride-Based Deep Eutectic Solvent

“…Both DESs have higher selectivity compared to studied ILs and sulfolane as an organic solvent . However, some DESs were used to extract toluene as an aromatic from heptane, − n -octane, and n -decane, and the potential of these solvents for extraction of toluene from cyclohexane has not been studied yet. Also, a DES constructed by mixing of tetrabutylphosphonium bromide and levulic acid was utilized for the separation of the cyclic hydrocarbon tetralin from dodecane in an LLE process .…”