Process for refining a heavy hydrocarbon-containing feedstock implementing a selective cascade deasphalting

Patent metadata

Field	Value
Publication number	US-10160924-B2
Application number	US-201415100723-A
Country	US
Kind code	B2
Filing date	Nov 27, 2014
Priority date	Dec 3, 2013
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

A process for refining a heavy hydrocarbon feedstock containing a) at least two stages of deasphalting in series to separate at least one fraction of asphalt, at least one fraction of heavy deasphalted oil, and at least one fraction of light deasphalted oil, at least one of the stages of deasphalting by a mixture of at least one polar solvent and at least one apolar solvent, the stages of deasphalting being implemented under the subcritical conditions of the mixture of solvents, b) a stage of hydrotreatment of at least a part of the fraction of heavy deasphalted oil, in the presence of hydrogen, c) a stage of catalytic cracking of at least a part of the fraction of light deasphalted oil, alone or in a mixture with at least a part of the effluent originating from stage b).

First claim

The invention claimed is:

1. A process for refining a heavy hydrocarbon feedstock, comprising
a) at least two stages of deasphalting in series carried out on said feedstock to separate at least one fraction of asphalt, at least one fraction of heavy deasphalted oil, referred to as heavy DAO, and at least one fraction of light deasphalted oil, referred to as light DAO, at least one of said stages of deasphalting being carried out by a mixture of at least one polar solvent and at least one apolar solvent, the proportions of said polar solvent and said apolar solvent in the mixture of solvents being adjusted according to the properties of treated feedstock and according to predetermined asphalt yield and/or predetermined quality of deasphalted oil, said stages of deasphalting being implemented under subcritical conditions of the mixture of solvents,
b) a stage of hydrotreatment of at least a part of the fraction of heavy deasphalted oil, referred to as heavy DAO, in the presence of hydrogen in at least one fixed-bed reactor containing at least one hydrodemetallization catalyst under conditions to obtain an effluent containing a reduced content of metals and Conradson carbon,
c) a stage of catalytic cracking of at least a part of the fraction of light deasphalted oil, referred to as light DAO, alone or in a mixture with at least a part of the effluent originating from stage b), in at least one fluidized-bed reactor under conditions to produce a gaseous fraction, a gasoline fraction, an LCO fraction, an HCO fraction and slurry.

2. The process according to claim 1 , comprising at least:
a1) a first stage of deasphalting comprising bringing the feedstock into contact with a mixture of at least one polar solvent and at least one apolar solvent, the proportions of said polar solvent and said apolar solvent being adjusted so as to obtain at least one fraction of asphalt and one fraction of complete deasphalted oil, referred to as complete DAO; and
a2) a second stage of deasphalting comprising bringing at least a part of the fraction of complete deasphalted oil, referred to as complete DAO, originating from stage a1) into contact with either an apolar solvent or a mixture of at least one polar solvent and at least one apolar solvent, the proportions of said polar solvent and said apolar solvent in the mixture being adjusted so as to obtain at least one fraction of light deasphalted oil, referred to as light DAO, and one fraction of heavy deasphalted oil, referred to as heavy DAO,
said stages of deasphalting being implemented under subcritical conditions of the apolar solvent or of the mixture of solvents.

3. The process according to claim 2 , in which the fraction of complete deasphalted oil originating from stage a1) extracted at least in part with the mixture of solvents is subjected to at least one stage of separation in which the fraction of complete deasphalted oil, referred to as complete DAO, is separated from the mixture of solvents or at least one stage of separation in which the fraction of complete deasphalted oil, referred to as complete DAO, is separated only from the apolar solvent.

4. The process according to claim 2 , in which the fraction of complete deasphalted oil, referred to as complete DAO, originating from stage a1) extracted at least in part with the mixture of solvents is subjected to at least two stages of separation in which the polar and apolar solvents are separated individually in each stage.

5. The process according claim 3 , in which the fraction of complete deasphalted oil separated from the solvents is sent into at least one stripping column before being sent to the second stage of deasphalting.

6. The process according to claim 1 comprising at least:
a′1) a first stage of deasphalting comprising bringing the feedstock into contact with either an apolar solvent or a mixture of at least one polar solvent and at least one apolar solvent, the proportions of said polar solvent and said apolar solvent in the mixture being adjusted so as to obtain at least one fraction of light deasphalted oil, referred to as light DAO, and an effluent comprising an oil phase and an asphalt phase; and
a′2) a second stage of deasphalting comprising bringing at least a part of the effluent originating from stage a′1) into contact with a mixture of at least one polar solvent and at least one apolar solvent, the proportions of said polar solvent and said apolar solvent being adjusted so as to obtain at least one fraction of asphalt and a fraction of heavy deasphalted oil, referred to as heavy DAO,
said stages of deasphalting being implemented under subcritical conditions of the apolar solvent or the mixture of solvents.

7. The process according to claim 6 , in which the effluent originating from stage a′1) is subjected to at least one stage of separation in which it is separated from the apolar solvent or the mixture of solvents or at least one stage of separation in which said effluent is separated only from the apolar solvent contained in the mixture of solvents.

8. The process according to claim 6 , in which the effluent originating from stage a′1) is subjected to at least two successive stages of separation to separate the solvents individually in each stage of separation.

9. The process according to claim 7 , in which the effluent separated from the solvents is sent into at least one stripping column before being sent to the second stage of deasphalting.

10. The process according to claim 1 , in which the proportion of polar solvent in the mixture of polar solvent and apolar solvent in at least one of the stages of deasphalting is between 0.1 and 99.9%.

11. The process according to claim 1 , in which the polar solvent is selected from the group consisting of pure aromatic solvents, naphthene-aromatic solvents, and polar solvents comprising heteroelements, or is a mixture thereof or is cuts rich in aromatics.

12. The process according to claim 1 , in which the apolar solvent contains a saturated hydrocarbon having a number of carbon atoms greater than or equal to 2.

13. The process according to claim 1 , in which the feedstock is selected from the group consisting of feedstocks of petroleum origin of the crude petroleum type, atmospheric residue, vacuum residue type originating from crude, a residual fraction originating from a pre-treatment process, a residual fraction originating from a conversion process, a residual fraction originating from direct liquefaction of lignocellulosic biomass alone, a residual fraction originating from direct liquefaction of lignocellulosic biomass in a mixture with coal and a fraction of residual petroleum.

14. The process according to claim 3 , in which the separated mixture of polar and apolar solvent is recycled to the stage of extraction, the quantities and the proportion of polar and apolar solvent being verified and readjusted from a makeup tank.

15. The process according to claim 3 , in which the individually separated polar and apolar solvents are recycled into their respective makeup tanks placed upstream of the stage of extraction in order to constitute the mixture of polar and apolar solvents in the proportions implemented in the stage of extraction.

16. The process according to claim 1 , in which the products obtained during stage b) are subjected to a stage of separation, from which the following are recovered:
a gaseous fraction;
a gasoil cut having a boiling point between 150 and 375° C.;
a gasoline cut having a boiling point between 20 and 150° C.;
a vacuum distillate (vacuum gas oil or VGO) cut;
a vacuum residue (VR) cut.

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Assignees

• Ifp Energies Now

Inventors

• Merdrignac Isabelle
• Majcher Jerome

Classifications

• C10G2400/16

  Residues · CPC title

• C10G2300/206

  Asphaltenes · CPC title

• C10G2400/02

  Gasoline · CPC title

• C10G69/14

  plural parallel stages only · CPC title

• C10G21/003

  Solvent de-asphalting · CPC title