Effect of deasphalting residue hydrotreating: A batch reactor study

The challenging task in upgrading of heavy oils is the removal of asphaltenes and metals, which end up in the metal sulfide and carbon accumulation on the catalyst surface, and as a result blocking the active sites and pores. Maya heavy crude residue (API =2°) contains infinite number and high concentration of complex sulfur compounds (5 wt.%), metals (Ni+V =850 ppm) and asphaltenes (30 wt.%), thus, a solvent deasphalted separation process is almost mandatory before hydrotreating. In the present contribution we have deasphalted the vacuum residue of Maya crude at different conditions in order to prepare samples with different concentration of asphaltenes. The deasphalted oil was distillated (to remove solvent) and hydrotreated in a batch reactor at conditions close to industrial practice. The effect of deasphalting was studied based on the different heteroatom removals, i.e. HDM, HDS, HDN and HDAs. Fresh and spent catalysts were characterized with different characterization techniques; which indicated that catalysts were deactivated due to the deposition of metal and carbon. The deposition of metal and carbon takes place preferentially at the entrance of pore, which causes pore mouth plugging.