Study on ultrasound assisted desulfurization of light gas oil using inorganic liquid

The feasibility of removing sulfur from real light gas oil using inorganic liquids (NaOH, Ca(OH) 2 and HCl) at various concentrations assisted with ultrasonication was investigated in a continuous flow setup. Experimental results showed that at the optimum operating time (40 min), 68% of sulfur was removed under mild conditions using 10 wt. % NaOH. Ultrasonication not only facilitated sulfur removal but also improved gas oil properties by decreasing density and viscosity by 1.40 and 4.42%, respectively, while the cetane number ( CN ) was increased by 7.0%. Solute selectivity ( S ) depending on sulfur mole fraction ( x S ) was correlated using StatPlus 6.7.1.0 software and the following values have been obtained: S = 53.869e –2.552 x S , and S = 29.573 – 41.878 x s for mixtures of 10% Ca(OH) 2 + S-compound + oil, and 10% NaOH + S-compound + oil, respectively. The correlation coefficients ( R 2 ) for the above equations were 0.9813 and 0.9611, respectively. An empirical correlation related to sulfur removal as a function of processing time and solvent concentration was found with R 2 = 0.956. The results of the present work confirmed the feasibility of employing the hybrid method of ultrasonication with using alkaline liquids for sulfur removal.