Study on Sulfur Conversion Characteristics in Catalytic Cracking of Coal Tar in the Presence of Dolomite-Supported Catalysts

To investigate sulfur redistribution in the process of tar catalytic cracking, nature dolomite, Ni-based dolomite, Fe-based dolomite, and Ni/Fe-based dolomite catalysts were prepared. The effect of thioanisole, 1-octanethiol, and 1-benzothiophene on sulfur distribution of tar cracking products was explored in a self-made fixed-bed reactor. The results showed that sulfur poisoning and carbon deposition had weakened the activity of Ni-based dolomite. The introduction of Ni decreased the relative contents of 1-octanethiol and thioanisole in tar. The additive Fe inhibited the formation of NiS, slowed down the carbon deposition, and promoted the conversion of thiol to thioether. The conversion of 1-octanethiol and thioanisole to phenyl disulfide could be promoted by MgO in dolomite. The relative contents of 1-benzothiophene in tar products of different modified dolomite catalysts increase slightly. With 1% Ni/2% Fe-D as the catalyst, high temperature was beneficial to the transformation from liquid-phase sulfu...