Patent ID: 6113775
Filing Date: 2000-09-05
Classification: C10G

Abstract:
A hydrocracking process, which process comprises the steps of:a.) dividing a hydrocracking process feed stream into a larger light first fraction and a smaller heavy second fraction,b.) passing the first fraction and hydrogen into a first hydrocracking zone comprising a first bed of hydrocracking catalyst maintained at hydrocracking conditions and generating a first effluent stream;c.) passing the second fraction and hydrogen into a second hydrocracking zone comprising a second bed of hydrocracking catalyst maintained at hydrocracking conditions, which conditions include substantially the same pressure as maintained in the first hydrocracking zone but which result in a lower overall conversion than in the first hydrocracking zone, and generating a second effluent stream;d.) subjecting both the first and the second effluent streams to vapor-liquid separation, recovering a vapor phase process stream from this vapor-liquid separation, and returning at least a portion of the vapor phase process stream to the first or second hydrocracking zone as a recycle gas stream;e.) passing liquid phase hydrocarbons recovered during said vapor-liquid separation of the first and second effluent streams into a single fractionation zone wherein the liquid phase hydrocarbons are separated and thereby producing at least a distillate boiling range product stream, a hydrocarbon recycle stream comprising unconverted hydrocarbons and a cyclics rejection stream, which is removed from the process; and,f.) passing the hydrocarbon recycle stream into the first hydrocracking reaction zone.