Extractive Desulfurization from Simulated Sulfur-Rich Naphtha

Upon extractive desulfurization of sulfur-rich oil obtained after recycling raffinate,the effects of single and compound extractants,temperature,and extractant/oil ratio on desulfurization rate,oil loss rate,extractant loss rate,and selectivity coefficient were investigated.The results showed that the thiophene existing in the simulated sulfur-rich oil could be further removed by extraction.The single-stage desulfurization rates achieved by dimethyl sulfoxide(DMSO)and sulfolane(SF)were 53.51%and 47.36%,respectively,while the selectivity coefficient of SF was 1.13,which was higher than that of DMSO(with a selectivity coefficient of 1.04).For the compound extractant,a single-stage desulfurization rate of 49.59%and a selectivity coefficient of 1.40 were obtained by using DMSO+10%MEA as the extractant,which was higher than that of SF.Upon using 50%SF+50%DMSO as the extractant,the single-stage desulfurization rate reached 50.92%with a selectivity coefficient of 1.32.Based on the comprehensive consideration,the DMSO+10%MEA extractant was selected as the best extractant for treating the sulfur-rich oil.