Solvent Regeneration Methods for Combined Dearomatization, Desulfurization, and Denitrogenation of Fuels Using Deep Eutectic Solvents

Abstract

Deep eutectic solvents (DESs) can be used as potential solvents for various applications. However, their recovery depends on both economic and environmental considerations. In this study, the possibilities for the recovery of methyl triphenyl phosphonium bromide/triethylene glycol (MTPPB/TEG 1:4) after the application of combined dearomatization, desulfurization, and denitrogenation of fuels are investigated. The DES was first prepared and characterized for its density, viscosity, and water content. Then, the single-stage liquid–liquid extraction was conducted in addition to testing the repetitive use of the DES. After that, two regeneration methods were studied: the stripping method (with n-heptane) and the washing method (with distilled water or diethyl ether). In addition, a parametric study was conducted to optimize the regeneration methods. The results showed that washing the used DES with distilled water was significantly more effective than stripping the DES with n-heptane. In terms of quinoline reduction, distilled water reduced the quinoline content in the DES from 3.2 to 2.1 wt %, while n-heptane showed a minor reduction in the quinoline content (3.2 to 3 wt %). It was also found that a much more effective recovery could be achieved by (i) increasing the DES-to-regeneration solvent mass ratio and (ii) increasing the number of wash cycles. Furthermore, the regeneration temperature did not have a significant effect on the recyclability of the DES. The results demonstrated that the regenerated DES was as effective in extraction as a fresh batch of DES.

Experimental and Mechanistic Investigation of Amide-Based Deep Eutectic Solvents for Quinoline Extraction and Separation from Wash Oil

“…More importantly, the use of DESs in the separation process of oil wash compounds solves the problems caused by traditional methods and is consistent with the principles of green chemistry. This will be a new direction for the sustainable development of the oil washing industry. − …”

Predicting the CO2 Capture Capability of Deep Eutectic Solvents and Screening over 1000 of their Combinations Using Machine Learning

“…A DES is a mixture of at least two or more hydrogen bond acceptors (HBAs) and hydrogen bond donors (HBDs) with mixture melting temperatures lower than those of their precursor constituents. DESs represent various solvent mixtures and have diverse chemical characteristics, which make them share many traits and properties with ILs. , DESs have many advantages, such as low vapor pressure, thermal stability, simple preparation, low volatility, and low cost, and they are relatively nontoxic (depending on the choice of constituents). , These characteristics have made them an attractive candidate not only for CO 2 capture but also for a wide range of applications. − …”

“…13,14 DESs have many advantages, such as low vapor pressure, thermal stability, simple preparation, low volatility, and low cost, and they are relatively nontoxic (depending on the choice of constituents). 12,15 These characteristics have made them an attractive candidate not only for CO 2 capture but also for a wide range of applications. 16−18 Many works have reported the utilization of DESs for CO 2 capture, 19−23 Li et al 19 were the first group to evaluate the implementation of DESs for CO 2 capture in 2008, where they reported the CO 2 solubilities in choline chloride (ChCl) and urea (U) with different molar ratios (1:1.5, 1:2, and 1:2.5) at various temperatures and pressures.…”