A catalytic hydrocracking reactor vessel includes enhanced components for the conversion of a hydrogen gas and fossil fuel feedstream to light liquid hydrocarbons. The reactor vessel comprises one or more of a reactor cup riser with a helical cyclonic separator conduit for separating a liquid and vapor product stream to provide an essentially vapor-free liquid recycle stream; a grid plate bubble cap with wall housing having serrated edges for producing small hydrogen bubbles of increased total surface area of bubbles at lower pressure drop; a feedstream inlet pipe sparger containing rows of downward directed slots for even distribution of the feedstream across the cross-sectional area of the reactor and providing free drain of solid particles from the sparger; and optionally a liquid recycle inlet distributor containing vertically curved plates for creating a whirling motion in the liquid recycle stream for better mixing with the feedstream with minimal solids settling.