METHOD OF HYDROCRACKING HYDROCARBON FEEDSTOCK Russian patent published in 2016 - IPC C10G47/00 C10G47/36 

FIELD: oil industry.

SUBSTANCE: invention relates to a hydrocracking method, comprising steps of: (a) combining a hydrocarbonaceous feedstock and a heavy bottom fraction recycle stream with a hydrogen-rich gas to obtain a mixture comprising hydrocarbonaceous feedstock and hydrogen; (b) catalytically hydrocracking mixture comprising hydrocarbonaceous feedstock and hydrogen in a hydrocracking zone to obtain a hydrocracked effluent; (c) separating hydrocracked effluent into a first vapour portion and a first liquid portion in a separation zone; (d) heating first liquid portion to form a vapourised first liquid portion; (e) feeding vapourised first liquid portion to a fractionation section producing individual product fractions including a heavy bottom fraction comprising unconverted oil at bottom zone of fractionation section; (f) withdrawing from fractionation section heavy bottom fraction; (g) splitting heavy bottom fraction in a stream for stripping and a heavy bottom fraction recycle stream; (h) stripping stream for stripping, with a stripping medium, in a counter current stripping column to form an overhead vapour and a stripped liquid; (i) feeding overhead vapour to fractionation section, to a recycle stream or to a position upstream fractionation section; and (j) removing at least a part of stripped liquid from counter current stripping column as a net purge of unconverted oil. Method includes a step (k) for heat energy transfer to one of said first stream, second stream or an optional third stream before feeding said stream into counterflow stripping column.

EFFECT: use of invention allows to increase conversion of heaviest and highest molecular weight materials into products, and to minimise need for purging by concentration of heavy polynuclear aromatic compounds into portion of unconverted oil stream.

14 cl, 3 ex, 7 tbl, 4 dwg