Evaluation of two imidazolium dicyanamide ionic solvents for extractive desulfurization of model fuels

The objective of this study is to assess the efficacy of two specific ionic liquids, namely 1-ethyl-3-methylimidazolium dicyanamide and 1-benzyl-3-methylimidazolium dicyanamide, as potential substitutes for conventional solvents in the removal of sulfur compounds from model fuels, a common challenge in the petroleum industry. This research examines the liquid-liquid equilibria (LLE) data of three different ternary systems to evaluate the ability of these ionic liquids to extract thiophene from aliphatic hydrocarbons, n-dodecane or n-hexadecane, simulating kerosene and diesel fuels, respectively. Liquid-liquid equilibrium measurements were conducted for these mixtures at a temperature of 313.15 K and atmospheric pressure to determine the solvents thiophene distribution coefficients and selectivities. Additionally, the impact of the length of the paraffin alkyl chain was examined. The experimental data were found to conform to the thermodynamic NRTL model, with an average root mean square deviation (rmsd) of 0.2165. Both ionic liquids efficiently extracted thiophene from n-dodecane and n-hexadecane, highlighting their potential for producing ultra-low sulfur fuels.