Upgrading of an Australian coal-derived liquid. 1. Initial activity dependence on loading for Ni-Mo/Al2O3 catalysts

Abstract A suite of ten Ni-Mo/Al 2 O 3 based catalysts of varying active species loading were tested in a batch autoclave reactor for their activity to upgrade an Australian coal-derived liquid. Of particular interest was their ability to remove phenols and to reduce the aromatic content of the liquid. Each catalyst had the same Ni:Mo wt% ratio, based on that employed by Shell in the production of their commercial 424 catalyst. Initial catalytic activity reached a maximum for catalysts with wt% loadings between 1.9% Ni/7.9% Mo to 3.7% Ni/15.1% Mo. This result was reinforced when the same catalysts were tested using a model feedstock containing compounds with functional groups typically found within coal-derived liquids. Those catalysts of highest activity were postulated to have an optimum NiMoS active phase dispersion. They possessed a balance between too few active sites arising from low active species loading, and a limited number of active sites resulting from bulk NiMoS phase at high loadings.