The two-stage hydrotreatment of Morwell coal liquid vacuum residue (CLVR) were examined using an autoclave and a commercial Ni-Mo/Al2O3 catalyst under the conditions of 390°C-2h and 430°C-2h, before and after the solvent fractionation with THF or the pretreatment with HCl/THF. The THF soluble fraction of CLVR was further treated using a cation-exchange resin or an activated alumina column chromatography. The pretreatment of whole CLVR with HCl/THF was more effective in the recovery and maintaining the catalytic activity of nitrogen removal than the THF extraction through the selective removal of specific nitrogen-containing compounds. The catalytic activity for the aluminatreated CLVR-THFS was maintained at the higher level in nitrogen removal than that for cation-exchange treated one, although the recovery was much higher in the latter than the former treatment. Based on the above results, the mechanism of catalyst deactivation is discussed.
