Novel phenolic deep eutectic solvents for desulfurisation of petrodiesel

Abstract

In this work, a novel production of “deep eutectic solvents (DESs)” has been utilised for the elimination ofsulfur composition, particularly from crude oil by liquid-liquid extraction. Herein, we present the firstdemonstration of the use of novel DESs formed by phenol, catechol, resorcinol and o-cresol as “hydrogenbond donors (HBDs)” with trimethyl hydroxyammonium chloride (ChCl) as the hydrogen bond acceptor toaffect the efficient separation of organosulfur compounds from diesel. These DES electrolytes have beenapplied for the sulfur extraction from Iraqi real diesel fuel as determined using X-ray florescence sulfurmeasurements. The optimisation condition factors in this research have been studied, containing reactiontime, the temperature of extraction process, the ratio of mass of diesel to DES and regeneration of DESs.The results indicated that phenol-based DESs extracted more than 38% of S-compounds from true dieselfuel when the mass ratio DES:fuel was 1:2 at 55 °C. Anhydrous ferric chloride (FeCl3) was also utilised asa catalyst in this work, where it was demonstrated that charge-dipole interaction between the DES andsulfide compounds was the key driving force behind the desulfurization process. We have shown that theextraction efficiency could be summarised as o-cresol + ChCl < catechol + ChCl < resorcinol + ChCl