| abstract |
A process and apparatus are shown for the improved utilization of catalysts in a hydrocracking system. The method comprises passing a hydrocarbon oil feedstock, preferably a heavy hydrocarbon residuum, upwardly through a particulate catalyst bed in a reaction zone maintained at high temperature and high pressure, together with hydrogen-containing gas; recycling a portion of the upwardly flowing oil together with a portion of the particulate catalyst to the bottom of the reaction zone while simultaneously pulverizing the minor proportion of the particulate catalyst to a fine powdered catalyst; and passing the recycled oil and finely powdered catalyst upwardly through the particulate catalyst bed in the reaction zone, with at least a portion of the powdered catalyst leaving the reactor with the treated effluent. Apparatus for practicing this process comprises a reactor vessel having a vertically mounted recycle conduit mounted therein, and pulverizing means, preferably a modified axial turbine high-shear mixer communicatingly connected to the bottom of the recycle conduit, for pulverizing recycled particulate catalyst to a fine powdery catalyst. Additionally, a pump is mounted to the outlet of the high-shear turbine mixer to provide positive fluid flow. |