N,N-二甲基甲酰胺对催化汽油的萃取脱硫

Desulphurization of FCC gasoline by N,N-dimethyl formamide extraction

为减轻流化催化裂化（FCC）汽油脱硫的负荷，基于油品分子管理理念，以N,N-二甲基甲酰胺（DMF）为萃取脱硫剂，去离子水为稀释剂，采用三级逆流萃取间歇模拟实验，考察了剂油比[V（DMF）／V（汽油）]、温度、稀释剂因素对2种FCC汽油脱硫效果的影响。确定的适宜萃取条件为：温度35～40℃，剂油比2．5～3．0，V（H2O）／V（DMF）为0．08。结果表明：在优化萃取条件下，2种FCC汽油经DMF处理后，含硫质量分数由360×10^-6降至43×10^-6脱硫率为88％，精制汽油收率约为50％；精制汽油硫含量满足欧Ⅳ标准要求，且其他性质及经济性均得以提高；DMF能有效地脱除FCC汽油中的硫醇类、硫醚类硫化物，对噻吩类硫化物也具有较高的选择性。

The effects of solvent/oil volume ratio, temperature,and diluent on desulfurization efficiency of fluid catalytic cracking（FCC） gasoline A and B were investigated with N, N- dimethyl formamide （DMF） as desulfurizing agent by three stage countercurrent extraction intermittent simulation experiments based on molecular scale management. The appropriate operating conditions were determined as follows： temperature 35 -40℃ ,volume ratio of DMF to gaso- line 2.5 - 3.0,volume ratio of diluent water to DMF 0.08. The results showed that under the above optimal conditions,FCC gasoline both A and B were extracted,the mass fraction of sulfur was reduced from 360 × 10^-6 to 43 × 10^-6 ,the desulfurization ratio and the yield of refining oil were 88% and 50% respectively, and the sulfur content of refining oil could meet the demand of European Ⅳ Standard. DMF could efficiently remove mercaptide, thioethers sulfide in FCC gasoline and had higher selectivity for thiophene sulfide.