# US 11,898,108 B2 · Hydrocracking process > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,898,108 B2 - Document ID: US11898108B2 - Status: Granted - Kind: B2 - Application number: 17/841,829 - Filed: 2022-06-16 - Published: 2022-12-22 - Granted: 2024-02-13 - Earliest claimed: 2021-06-17 - Assignees: Axens - Applicants: Axens - Inventors: Jerome Bonnardot; Hugues Dulot; Alexis Paillier; Jerome Pigourier; Nicolas Pupat - Web page: https://patentgrep.com/patent/US11898108B2 ## CPC - C10G 47/00: Cracking of hydrocarbon oils, in the presence of hydrogen or hydrogen- generating compounds, to obtain lower boiling fractions (C10G15/00 takes precedence; destructive hydrogenation of non-melting solid carbonaceous or similar materials C10G1/06) - C10G 67/02: plural serial stages only - B01D 3/143: {by two or more of a fractionation, separation or rectification step} - B01D 3/346: {the gas being used for removing vapours, e.g. transport gas} - B01D 3/42: Regulation; Control - B01J 19/0006: {Controlling or regulating processes (controlling or regulating in general G05)} - B01J 19/245: {placed in series} - B01J 2219/0004: Processes in series - B01J 2219/00162: controlling the pressure - C10G 2300/308: Gravity, density, e.g. API - C10G 2300/4081: Recycling aspects - C10G: CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION (cracking to hydrogen or synthesis gas C01B; cracking or pyrolysis of hydrocarbon gases to individual hydrocarbons or mixtures thereof of definite or specified constitution C07C; cracking to cokes C10B); RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS ## Abstract A process for hydrocracking a petroleum feedstock involves: (a) hydrocracking the feedstock to obtain a hydrocracked effluent; (b) liquid/gas separation of the effluent to obtain a gaseous effluent and a liquid effluent; (c) fractionating the liquid effluent at a pressure P1, producing a first distillate and a first residue, (d) recycling a first portion of the first residue to hydrocracking, (e) rectifying a second portion of the first residue at a pressure P2 lower than or equal to the pressure P1, to obtain a secondary distillate, a secondary residue and a vapor stream, (f) purging a portion of the secondary residue, and (g) recycling all or part of the secondary distillate to hydrocracking. ## Claims ### Claim 1 A process for hydrocracking a petroleum feedstock (1) comprising at least 10% by volume of compounds that boil above 340° C., said process comprising: (a) at least one step of hydrocracking the feedstock in order to obtain a hydrocracked effluent; (b) a step of liquid/gas separation of the hydrocracked effluent in order to obtain a gaseous effluent (5) and a liquid effluent (9); (c) a step of fractionating said liquid effluent (9), in at least one fractionating column (12), at a pressure P1 at the bottom of the column, to produce at least a first distillate (13, 14) and a first residue (15), (d) a step of recycling a first portion (18) of said first residue (15) to the hydrocracking step and/or at least one of the hydrocracking steps, (e) a step of rectifying a second portion (20) of the first residue (15) obtained in the fractionating step, carried out in at least one column (21), at a pressure P2 at the top thereof which is at least 0.05 MPa lower than pressure P1, to obtain at least a secondary distillate (23), a secondary residue (16) and a vapor stream (22), (f) a step of purging at least one portion or all of the secondary residue (16), (g) a step of recycling all or part of said secondary distillate (23) to the hydrocracking step or to at least one of the hydrocracking steps, after an optional gas separation step. ### Claim 2 (depends on 1) The process according to claim 1, wherein said process is free of a step of recycling, to the fractionating step (c), all or part of the secondary distillate (23) and/or all or part of the secondary residue (16) and/or all or part of the overhead vapor stream (22) which result from the rectifying step (e). ### Claim 3 (depends on 1) The process according to claim 1, wherein the pressure P2 at the top of the column (21) of the rectifying step is lower than the pressure P1 in the bottom of the column of the fractionating step (c) by at least 0.06 MPa. ### Claim 4 (depends on 1) The process according to claim 1, wherein the pressure P2 at the top of the column (21) of the rectifying step (e) is lower than atmospheric pressure. ### Claim 5 (depends on 1) The process according to claim 1, wherein the rectifying step (e) uses a distillation column (21) equipped with feed tray(s), optionally with packing and with draw-off tray(s), and in that: the first residue (15) from the fractionating step (c), optionally at least partially vaporized, feeds said distillation column (21) at at least one feed tray, the secondary distillate (23) is drawn off from said distillation column (21) at a draw-off tray, the secondary residue (16) is drawn off at the bottom of said distillation column (21), and the overhead vapor stream (22) is cooled. ### Claim 6 (depends on 1) The process according to claim 1, wherein the rectifying step (e) uses a distillation column (21) equipped with feed tray(s), optionally with packing and with draw-off tray(s), and step (e) is carried out with a stripping gas. ### Claim 7 (depends on 1) The process according to claim 1, wherein, in the rectifying step (e), the first residue (15) is fed at a temperature of between 250° C. and 400° C. ### Claim 8 (depends on 1) The process according to claim 1, wherein the second portion (20) of the first residue (15) which is treated in the rectifying step (e) corresponds to at most 50% by weight of the first residue obtained in the fractionating step (c). ### Claim 9 (depends on 1) The process according to claim 1, wherein, in the purging step (f), at least 20% by weight of the secondary residue (16) is purged. ### Claim 10 (depends on 1) The process according to claim 1, wherein the fractionating step and/or the rectifying step are carried out with a stripping gas. ### Claim 11 (depends on 10) The process according to claim 10, wherein the stripping gas of the fractionating step is injected at a pressure of between 0.2 and 0.4 MPa, and/or the stripping gas of the rectifying step is injected at a pressure of between 0.001 and 0.35 MPa. ### Claim 12 (depends on 1) The process according to claim 1, wherein said process has one or two hydrocracking steps (a), and at least one of said one or two hydrocracking steps is preceded by a hydrotreating step (h). ### Claim 13 (depends on 1) The process according to claim 1, wherein the pressure P2 at the top of the column (21) of the rectifying step is lower than the pressure P1 in the bottom of the column of the fractionating step (c) by at least 0.08 MPa. ### Claim 14 (depends on 1) The process according claim 1, wherein the pressure P2 at the top of the column (21) of the rectifying step (e) is between 1333 Pa and 0.08 MPa. ### Claim 15 (depends on 1) The process according to claim 1, wherein the second portion (20) of the first residue (15) which is treated in the rectifying step (e) corresponds to at most 20% by weight of the first residue obtained in the fractionating step (c). ### Claim 16 (depends on 1) The process according claim 1, wherein, in the purging step (f), at least 40% by weight of the secondary residue (16) is purged. ### Claim 17 (depends on 1) The process according to claim 1, wherein said process is free of a step of recycling, to the fractionating step (c), all or part of the overhead vapor stream (22) resulting from the rectifying step (e). ### Claim 18 (depends on 1) The process according to claim 1, wherein pressure P1 is between 0.2 and 0.4 MPa. ### Claim 19 A plant for hydrocracking a petroleum feedstock comprising at least 10% by volume of compounds that boil above 340° C., said plant successively comprising: (a) at least one section (2) for hydrocracking the feedstock (1) in order to obtain a hydrocracked effluent, (b) at least one section (4) for liquid/gas separation of the hydrocracked effluent in order to obtain a gaseous effluent (5) and a liquid effluent (9), (c) a section for fractionating said liquid effluent, comprising at least one column (12), at a pressure P1 at the bottom of the column, to produce at least a first distillate (13, 14) and a first residue (15), (d) a line for recycling a first portion (18) of said first residue (15) to one of the at least one hydrocracking section (2), (e) a section for rectifying a second portion (20) of the first residue (15) obtained in the fractionating zone, comprising at least one column (21), at a pressure P2 at the top thereof which is at least 0.05 MPa lower than the pressure P1, to obtain at least a secondary distillate (23), a secondary residue (16) and a vapor stream (22), (f) a section for purging at least one portion, or all, of the secondary residue (16), and (g) a line for recycling all or part of said secondary distillate (23) to the hydrocracking section (2) or at least one of the hydrocracking sections, after an optional gas separation section, wherein said plant is free of a line for recycling all or part of the of the overhead vapor stream (22) resulting from the rectifying step (e). ### Claim 20 (depends on 19) The plant according to claim 19, wherein said plant is free of a line for recycling all or part of the secondary distillate (23) and/or all or part of the secondary residue (16) which result from the rectifying zone (e) to the fractionating zone (c). ### Claim 21 (depends on 19) The plant according to claim 19, wherein the rectifying zone (e) is equipped with pressure control devices, either of pressure regulator type if the pressure P2 is greater than atmospheric pressure, or of vacuum device type if the pressure P2 is lower than atmospheric pressure. ### Claim 22 (depends on 19) The plant according to claim 19, further comprising: one or two hydrocracking section(s) (2) equipped with a feedstock inlet line (1) and a hydrogen inlet line (8), the fractionating section (12) comprising at least one distillation column equipped with trays, said distillation column producing a first distillate and a first residue (15), the section for rectifying a second portion (20) of the first residue (15), comprising at least one distillation column (21) equipped with trays and/or packing, said distillation column of the section for rectifying a second portion (20) of the first residue (15) comprising: at least one inlet line (20) for the second portion of the first, at least partially vaporized residue at at least one feed tray, at least one line (22) connected to a pressure regulation or vacuum system, at least one line (23) for drawing off at least the secondary distillate at a draw-off tray, at least one line (16) for drawing off, at the bottom of the column, said secondary residue, at least one optional line (26) for injecting a stripping gas, the injection point being located below the feed tray of the stream (20), and an optional line (18) for recycling a portion of said secondary residue resulting from the fractionating section directly to the or one of the hydrocracking section(s).