Abstract: In the catalytic hydrogenation of a substance in a water-immiscible organic liquid medium, a metallic hydrogenation catalyst is conveniently and effectively dispersed in the reaction mixture by addition as an emulsion of an aqueous solution of a salt of the metal in the liquid medium. The method is particularly applicable to the liquefaction of coal.

Abstract: Solid, hydrocarbonaceous materials, such as coal, are converted to valuable liquid and gaseous products by an efficient process comprising:(1) preparing a slurry from slurry oil, a hydrogenation catalyst and the hydrocarbonaceous material;(2) hydrogenating the hydrocarbonaceous material to liquid and gaseous hydrogenation products, the liquid hydrogenation product containing suspended particles of ash and catalyst;(3) gravitationally separating the liquid hydrogenation product into a first stream and a second stream, the first stream having both a lower ash concentration than the liquid hydrogenation product and a greater catalyst:ash ratio than the second stream;(4) recycling at least a portion of the first stream for use as at least a portion of the slurry oil and thereby recycling at least a portion of the catalyst.

Abstract: In the hydrogenation of coal slurried in recycle oil in the presence of a suspended hydrogenation catalyst, a substantial proportion of the catalyst can be recovered for recycle to the process by using a catalyst which is significantly more finely divided than the ash particles from the coal, subjecting the hydrogenated slurry to a gravity concentration process whereby the coarser, ash particles are selectively concentrated in a lower layer and a relatively larger proportion of the finer catalyst particles remain suspended in the supernatant oil, and recycling at least a part of the supernatant oil containing suspended catalyst to the coal hydrogenation process.