Behavior of coal mineral remaining in coal derived liquid on hydrotreating catalysts

In order to make clear the behavior of coal mineral remaining in coal liquid on the hydrotreating catalyst, a Wandoan coal derived liquid containing high contents of liquefaction solid was hydroprocessed over the Ni-Mo-γ-Al2O3 catalyst having bimodal pore size distributions.In these liquefaction residues, kaolin and quartz were not chemically altered and magnetite was undergone chemical transformation to pyrrhotite during hydroprocessing. From the shell like deposits of these metals around the spent cata lysts, these matters might be finely dispersed particles that had equivalent spherical diameter larger than about 1-2μm, which corresponded to maximum size of macropore in used catalysts.Titanium and calcium metals, which were more concentrated in THF insoluble residue in feed coal liquid, were tend to accumulate in preasphaltene after hydro processing. Furthermore from the more penetrated depth profile of titanium and calcium metals, these metal containing matters might have equivalent spherical diam eter larger than about 0.6μm and 4.4nm micro-pore diameter were too small to be utilized against carbonaceous material deposits. Because active sites might be occupied with sodium metal, which interacted more strongly with those than titanium and calcium metals, titanium and calcium metals migrated more deeper on the catalyst pore walls by surface diffusions.As a result, silicon and iron metals were tend to plug the catalyst pore mouth and sodium, alkaline earth metals and titanium metals were tend to poison active sites and change micro-pore structure.