Desulfurization of Gasoline Using Deep Eutectic Solvents Based on Tetrabutylammonium Bromide

The present study investigated the viability of deep eutectic solvents (DESs) to extract dibenzothiophene (DBT) from model gasoline (iso-octane). Tetrabutylammonium bromide (TBAB)-based DES showed significant DBT extraction capability from the model fuel oil. Furthermore, the sigma profile confirmed that all TBAB-based DES had a significant capacity for DBT extraction from the model oil. The affinity order for the TBAB-based DES is as follows: TBAB/TEG (tri-ethylene glycol) > TBAB/PA (propionic acid) > TBAB/EG (ethylene glycol). To achieve maximum DBT extraction, the influencing parameters were adjusted, and 89% DBT extraction was achieved using the optimum conditions of oil to DES volume ratio of 1:1, with a DBT concentration of 500 ppm, residence time of 30 min, an extraction temperature of 303 K, and extraction stirring speed of 200 rpm.