Extractive Desulfurization from Simulated Sulfur-Rich Naphtha

Upon extractive desulfurization of sulfur-rich oil obtained after recycling raffinate, the effects of single and com-pound extractants, temperature, and extractant / oil ratio on desulfurization rate, oil loss rate, extractant loss rate, and selec-tivity 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 selec-tivity 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.