Beneficial roles of carbon black additives in slurry phase hydrocracking of vacuum residue

Effects of carbon black (CB) additives with dispersed MoS2 catalysts (d-MoS2) on the slurry phase hydrocracking (HCK) of vacuum residue (VR) were studied in an autoclave batch reactor at 693 K and 9.5 MPa H-2. For comparison, commercial NiMo catalysts supported on large and small pore volume Al2O3 (-LP, -SP) were also applied for the VR HCK. The structure of the catalysts was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and extended X-ray absorption fine structure (EXAFS). The dispersed MoS2 (d-MoS2) was observed to form nanosized single slabs of 8.4 nm, while in the presence of CB the particle size of the d-MoS2-CB became even smaller (4.8 nm). A series of recycle runs of the VR HCK revealed high activity and stability of d-MoS2-CB followed by d-MoS2 > NiMo-LP > NiMo-SP. The kinetic analysis also demonstrated that the d-MoS2-CB shows a high asphaltene conversion with minimizing coke formation.