Process for the preparation of olefins, involving de-asphalting, hydroconversion, hydrocracking and steam cracking

Patent metadata

Field	Value
Publication number	US-12098333-B2
Application number	US-202017766794-A
Country	US
Kind code	B2
Filing date	Oct 2, 2020
Priority date	Oct 7, 2019
Publication date	Sep 24, 2024
Grant date	Sep 24, 2024

Abstract

The present invention relates to a process for producing olefins from a hydrocarbon feedstock 11 having a sulfur content of at least 0.1 weight %, an initial boiling point of at least 180° C. and a final boiling point of at least 600° C.

First claim

The invention claimed is:

1. A process for producing olefins from a hydrocarbon feedstock ( 1 ) with a sulfur content of at least 0.1 weight %, an initial boiling point of at least 180° C. and a final boiling point of at least 600° C., said process comprising the following steps:
a) a deasphalting step a) by extraction of said heavy hydrocarbon feedstock ( 1 ) using a solvent ( 2 ) or a mixture of solvents, enabling the production of an asphalt-comprising fraction ( 4 ) and of a deasphalted oil fraction ( 3 ),
b) a step b) of hydroconversion performed in an ebullated-bed reactor, in which the asphalt fraction ( 4 ) is contacted, in the presence of hydrogen, with a hydroconversion catalyst, said step enabling the production of an effluent ( 5 ),
c) a step c) of separation of the effluent ( 5 ) obtained from the hydroconversion step b) into a gaseous fraction ( 6 ), a fraction ( 7 ) comprising compounds with a boiling point of between 180 and 540° C., and a fraction ( 8 ) comprising compounds with a boiling point of less than 180° C.,
d) a step d) of extraction of the aromatics from at least part of the deasphalted oil fraction ( 3 ) obtained from the deasphalting step a), and from at least part of the fraction ( 7 ) obtained from the separation step c), using a polar solvent ( 11 ), enabling the production of an extract fraction ( 9 ) and of a raffinate fraction ( 10 ),
e) a step e) of fixed-bed hydrocracking of at least part of the extract fraction ( 9 ) obtained from the extraction step d) in the presence of hydrogen ( 12 ) and of a hydrocracking catalyst, enabling the production of an effluent ( 13 ),
f) a step f) of separation of the effluent ( 13 ) obtained from the fixed-bed hydrocracking step e) into at least one gaseous fraction ( 15 ) and at least one liquid fraction ( 14 ) comprising compounds with a boiling point of less than or equal to 350° C.,
g) a step g) of steam cracking of the raffinate fraction ( 10 ) obtained from the extraction step d), of the fraction ( 8 ) obtained from the separation step c) and of the liquid fraction ( 14 ) obtained from the separation step f), enabling the production of an effluent ( 16 ),
h) a step h) of separation of the effluent ( 16 ) obtained from the steam cracking step g), enabling the production of at least one hydrogen-comprising fraction ( 17 ), of an ethylene-comprising fraction ( 18 ), of a propylene-comprising fraction ( 19 ) and of a fraction ( 20 ) comprising pyrolysis oil.

2. The process according to claim 1 , in which the deasphalting step a) is performed under conditions enabling the production of the deasphalted oil fraction ( 3 ) with a low asphaltene content, and of the asphalt-comprising fraction ( 4 ), which has a softening point of less than 120° C.

3. The process according to claim 1 , in which the solvent ( 2 ) used in step a) is an apolar solvent containing at least 80% by volume of saturated hydrocarbon(s) comprising a carbon number of between 3 and 5.

4. The process according to claim 1 , in which the separation step c) comprises a vacuum distillation enabling the production of at least one vacuum distillate fraction and of at least one vacuum residue fraction, wherein at least part of the at least one vacuum distillate fraction contains at least part of the fraction ( 7 ).

5. The process according to claim 4 , in which the separation step c) comprises, upstream of the vacuum distillation, an atmospheric distillation enabling the production of at least one atmospheric distillate fraction and at least one atmospheric residue fraction, said atmospheric residue fraction being sent into said vacuum distillation, enabling the production of the at least one vacuum distillate fraction and of the at least one vacuum residue fraction.

6. The process according to claim 1 , in which the polar solvent employed in the aromatics extraction step d) is selected from furfural, N-methyl-2-pyrrolidone (NMP), sulfolane, dimethylformamide (DMF), dimethyl sulfoxide (DMSO) and phenol, or is a mixture of at least some of these solvents.

7. The process according to claim 1 , in which the hydrocracking step e) is implemented at a temperature of between 340 and 480° C. and at an absolute pressure of between 5 and 25 MPa.

8. The process according to claim 1 , in which the hydrocracking step e) is performed so as to produce a yield of liquid compounds with a boiling point of less than 180° C. of more than 50 weight % of the feedstock entering the hydrocracking step e).

9. The process according to claim 1 , in which the separation step f) comprises at least one atmospheric distillation enabling the production of at least one liquid fraction ( 14 ) comprising compounds with a boiling point of less than 350° C. and a liquid fraction comprising vacuum distillate comprising compounds with a boiling point of greater than 350° C.

10. The process according to claim 9 , in which the liquid fraction ( 14 ) and the fraction comprising vacuum distillate are sent to the steam cracking step g).

11. The process according to claim 1 , in which part of a fraction ( 8 ) comprising compounds with a boiling point of less than 180° C., obtained from the separation step c), is introduced into the steam cracking step g).

12. The process according to claim 1 , in which the steam cracking step g) is performed in at least one pyrolysis furnace at a temperature of between 700 and 900° C., under a pressure of between 0.05 and 0.3 MPa, for a residence time of less than or equal to 1.0 second.

13. The process according to claim 1 , in which the cuts rich in saturated compounds which are obtained from the light gases or from a pyrolysis gasoline obtained from the separation step h) are recycled into the steam cracking step g).

14. The process according to claim 1 , in which the pyrolysis oil fraction ( 20 ) is subjected to an additional separation step so as to produce a light pyrolysis oil, comprising compounds with a boiling point of less than 350° C., and a heavy pyrolysis oil, comprising compounds with a boiling point of greater than 350° C., said light pyrolysis oil is injected upstream of the hydrocracking step e), and said heavy pyrolysis oil is injected upstream of the hydroconversion step b) and/or of the deasphalting step a).

Assignees

• Ifp Energies Now

Inventors

• Weiss Wilfried
• Merdrignac Isabelle

Classifications

• C10G2400/20

  C2-C4 olefins · CPC title

• C10G2300/44

  Solvents · CPC title

• C10G2300/4012

  Pressure · CPC title

• C10G2300/4006

  Temperature · CPC title

• C10G2300/301

  Boiling range · CPC title