Elemental sulfur as an effective promoter for the catalytic hydrocracking of Arabian vacuum residue

The effect of elemental sulfur on the conversion of residue for catalytic hydrocracking of Arabian heavy vacuum residue was tested using an autoclave reactor. The reaction condition was 703 K and 5.0 MPa of hydrogen partial pressure. Adding only a small amount of sulfur increased the conversion of residue from 64 to 80 wt%, as well as the yield of middle distillate from 23 to 31 wt%. This should be attributed to the free-radical initiation effect of sulfur. Sulfur promoted the decomposition of residue at the catalytic hydrocracking condition.