Abstract: A multiple-stage process for the conversion of a heavy hydrocarbonaceous charge stock, contaminated by the inclusion of sulfurous and nitrogenous compounds, into lower-boiling hydrocarbon products. Fresh feed and hydrogen are introduced into a catalytic hydrorefining reaction zone to convert the contaminants into ammonia and hydrogen sulfide. Hydrorefined product effluent is admixed with the effluent from a catalytic hydrocracking reaction zone, and separated into various product streams. Hydrocarbons boiling above the predetermined end boiling point of the desired end product and hydrogen are introduced into the catalytic hydrocracking reaction zone for conversion to lower-boiling hydrocarbons. Hydrocracked effluent is admixed with the hydrorefined effluent as aforesaid.

Abstract: A process for fractionating hydrocarbons wherein the overhead vapors of two fractionation columns are admixed and then condensed in a single overhead condenser. The overhead liquid is divided into two portions, one of which is used to supply reflux to the column receiving the process feed stream and the other as feed to the second column. Also disclosed is a control system for use on the process.

Abstract: A multiple-stage hydrocarbon steam reforming process for producing a methane-rich substitute natural gas. A portion of the first stage efluent is condensed, water is removed therefrom and the remainder is recycled to combine with the fresh charge stock to the first stage. Following one stage of methanation, or shift conversion, both steam and carbon dioxide are removed prior to effecting additional reactions in a second methanation stage.

Abstract: Separation of the catalyst-containing product effluent from a fluid catalytic cracking unit is effected in the main column by a technique which involves removing a light naphtha fraction as the single overhead stream and separately withdrawing a heavy naphtha fraction as a lower side-cut. The latter is stripped of light naphtha (for recycle to the main column) and recovered as a product stream. Preferably a portion of the heavy naphtha fraction (as withdrawn) is cooled and combined with the light naphtha overhead reflux stream.