A Characterization of Bacterium for FCC Diesel Oil Desulfurization

Fluid catalytic cracking (FCC) diesel oil has a high sulfur content, which exists mainly as thiophene, dibenzothiophene, and their derivatives. These kinds of sulfur compounds are not easy to be removed by hydrogenation and other desulfurization methods. HT1 strain, which has high desulfurization ability by using dibenzonthiophene as the sole source of sulfur, was screened. Best conditions of conservation reagent were studied by orthogonal test and analyzed the sequence of the factors. The optimal fermented conditions, which are obtained by using the orthogonal, are following: temperature 30°C, dibenzonthiophene 102.0 mg/L, NH4NO3 2.0 g/L, glycerol 5 g/L, cultivation time four days, and pH 7.0. The sulfur source has no obvious effect on the growth of strains. But the best desulfurization results can be achieved by using dibenzonthiophene as the sole source of sulfur. The desulfurization effect of other sulfur compounds is related to the structure of sulfur compounds. However, the desulfurization ability of the HT1 strain for FCC diesel oil is weak, which means the next step would focus on improving the desulfurization ability.