Extraction process of sulfur compounds from fuels with protic ionic liquids

Abstract

Sulfur compounds in fuels are hazardous to the environment and present a great challenge. In this study, a series of protic ionic liquids (PILs) was designed, such as N,N-dimethyl-N-cyanoethyl ammonium butyratecyanoethyl ammonium acetate ([DMAPN] + [Ac] À ), N,N-dimethyl-N-cyanoethyl ammonium formate ([DMAPN] + [Fo] À ), N,N-dimethyl-N-(2-(2-hydroxyethoxy)) ammonium propionate ([DMEE] + [Pr] À ), N,Ndimethyl-N-hydroxyethyl ammonium propionate ([DMEA] + [Pr] À ), N,N-dimethyl-N-hydroxyethyl ammonium acetate ([DMEA] + [Ac] À ), N,N-dimethyl-N-hydroxyethyl ammonium formate ([DMEA] + [Fo] À ), N,N-dimethyl-N-butyl ammonium acetate ([DMBA] + [Ac] À ), N-methyl-N-hydroxyethyl ammonium propionate ([MEA] + [Pr] À ), and N-methyl-N-hydroxyethyl ammonium acetate ([MEA] + [Ac] À ), and their extraction desulfurization capability was evaluated. Through selection, two PILs were chosen to optimize the desulfurization process. The results showed that benzothiophene (BT) and thiophene (T) can be removed using PILs effectively. Both cations and anions have an influence on the extraction efficiencies.However, cations have a greater influence on the desulfurization process. Under optimal conditions, the extraction efficiency can be higher than 80% for one cycle. After 6-8 cycles, the removal efficiency could reach up to 99.5%. It is worth noting that the PILs could be recycled via simple vacuum distillation.After 4 times of recycling, the desulfurization efficiency changed slightly. Finally, a mechanistic study shows that hydrogen bonding interactions between the sulfur atom and active hydrogen of the PILs account for the high desulfurization efficiency. This green process would provide a new route for the extraction desulfurization of fuels.

Copper extraction using protic ionic liquids: Evidence of the Hofmeister effect

“…Ionic forms should therefore predominate in the PIL. PILs have been studied in the extraction of organic [19][20][21] and biomolecular species [22,23] from aqueous phase, and have seen some application in electrodeposition of metals [24][25][26]. However, there has been relatively little study of PILs for metal extraction [27][28][29][30].…”

Ionothermal Synthesis of Metal Oxide-Based Nanocatalysts and Their Application towards the Oxidative Desulfurization of Dibenzothiophene

“…is has led to the formulations of stringent regulations for fuel specifications, which has tremendously increased the demand of deep desulfurization of transportation fuels. Particularly, the presence of sulfur-containing compounds, such as sulfides, disulfides, and thiophenes in transportation fuels, which typically produce SOx, is a major cause of air contamination [2]. To limit the emission of hazardous sulfur compounds, several countries have legislated stringent environmental regulations and strongly promoted the desulfurization of fuels ("S-free" fuels (S content <10 ppm)) [3].…”

3D-printing of integrated spheres as a superior support of phosphotungstic acid for deep oxidative desulfurization of fuel

“…Most importantly, because of the poor activity to aromatic sulfur compounds [13] , realization of deep desulfurization via HDS process requests harsher reaction conditions [14] . Thus, numerous desulfurization technologies, such as extractive desulfurization (EDS) [15][16][17][18] , adsorptive desulfurization (ADS) [19][20][21] , oxidative * Corresponding author. E-mail address: zhuws@ujs.edu.cn (W. Zhu).…”