Nowadays there are serious regulations to eliminate sulfur from fuels because the SOx created through the combustion of fuel containing sulfur compounds which causes air pollution and have hazardous environmental influence. In present paper experimental data on extractive desulfurization (EDS) of dibenzothiophene (DBT), thiophene, benzothiophene, and other sulfur derivatives from liquid fuel using trihexyl(tetradecyl)phosphonium chloride [THTDP]Cl has been presented. The FTIR, NMR and TG/DSC spectra have been discussed for the molecular confirmation and thermal stability of [THTDP]Cl. Further, conductivity, solubility, and viscosity analysis were carried out. The effects of reaction time, temperature, sulfur compounds, ultra-sonication, recycling and regeneration on DBT removal from fuel were also investigated. In EDS, the DBT removal in n-dodecane was 81.5% for mass ratio of 1:1 in 30 min at 30 degrees C under the mild reaction conditions. Also, real fuels desulfurization and multistage extraction was examined. The results of the present work positively offer valuable information on synthesis, and application of phosphonium ionic liquids as promising solvents for EDS. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.