Control of coke morphology in delayed coking

Patent metadata

Field	Value
Publication number	US-10053630-B2
Application number	US-201514698398-A
Country	US
Kind code	B2
Filing date	Apr 28, 2015
Priority date	May 14, 2014
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

A delayed coking process in which shot coke and thermally cracked coker products are produced from a sponge coke- and/or transition coke-forming resid feed comprising sponge coke asphaltenes by mixing heteroatom (preferably nitrogen) containing asphaltenes from a shot coke-forming resid with a heated sponge coke-forming resid to form shot coke directing asphaltene aggregates in the resid. The mixture of resid with the added asphaltene is held at an elevated temperature to allow co-aggregates of sponge coke and shot coke asphaltenes to form which, upon delayed coking promote the production of a free-flowing shot coke product.

First claim

The invention claimed is:

1. A delayed coking process to form shot coke and thermally cracked coker products from a sponge coke- and/or transition coke-forming resid which comprises:
mixing asphaltene derived from a shot coke-forming petroleum residual feed in the form of a solution in a mixture of an aromatic solvent and water with a heated sponge coke-and/or transition coke-forming resid feed to form shot coke asphaltene aggregates in the sponge coke and/or transition coke forming resid,
holding the mixture of sponge coke- and/or transition coke-forming resid and the shot coke asphaltene aggregates at an elevated temperature in the range of 100 to 150° C. to allow co-aggregates of sponge coke and shot coke asphaltenes to form,
heating the heated sponge coke- and/or transition coke-forming resid containing the co-aggregates of sponge coke and shot coke asphaltenes to a delayed coking temperature to form shot coke and thermally cracked coker products;
wherein the relative proportion of aromatic solvent to water in solution with the asphaltene derived from the shot coke-forming petroleum residual feed is at least 1 percent v/v relative to the aromatic solvent and not more than 20 percent v/v-; and
wherein the proportion of the asphaltene derived from a shot coke-forming petroleum residual feed in the mixture of sponge- coke and/or transition coke-forming resid and the shot coke asphaltene aggregates is at least 5 weight percent of the sponge coke- and/or transition coke-forming resid and not more than 20 weight percent.

2. A delayed coking process according to claim 1 in which the asphaltene derived from the shot coke-forming petroleum residual feed comprises an asphaltene with aromatic clusters containing an average at least 1 heteroatom per cluster.

3. A delayed coking process according to claim 2 in which the asphaltene derived from the shot coke-forming petroleum residual feed comprises an asphaltene with aromatic clusters containing 4 or 5 aromatic rings with at least 1 heteroatom per cluster.

4. A delayed coking process according to claim 3 in which the asphaltene derived from the shot coke-forming petroleum residual feed comprises an asphaltene with aromatic clusters containing 4 or 5 aromatic rings with an average of 1 to 2 heteroatoms per cluster.

5. A delayed coking process according to claim 2 in which the asphaltene derived from the shot coke-forming petroleum residual feed comprises an asphaltene with aromatic clusters containing 4 or 5 aromatic rings with an average of 1 to 2 heteroatoms per cluster, at least one of which is nitrogen.

6. A delayed coking process according to claim 2 in which the asphaltene derived from the shot coke-forming petroleum residual feed comprises an asphaltene with a nitrogen content of at least 0.5 wt. percent.

7. A delayed coking process according to claim 6 in which the asphaltene derived from the shot coke-forming petroleum residual feed comprises an asphaltene with a nitrogen content of at least 0.5 wt. percent, and at least 250 ppmw of nickel plus vanadium.

8. A delayed coking process according to claim 7 in which the asphaltene derived from the shot coke-forming petroleum residual feed comprises an asphaltene with a nitrogen content of at least 0.5 wt. percent, at least 250 ppmw of nickel plus vanadium and not more than 10.5 wt. percent hydrogen.

9. A delayed coking process to form shot coke and thermally cracked coker products from a feed comprising a sponge coke- and/or transition coke-forming petroleum vacuum resid which comprises:
heating the sponge coke- and/or transition coke-forming petroleum vacuum resid to a pumpable temperature,
(ii) mixing the heated sponge coke- and/or transition coke-forming petroleum vacuum resid with asphaltene derived from shot coke-forming petroleum vacuum resid in the form of a solution in a mixture of an aromatic solvent and water,
(iii) forming aggregates of the asphaltene derived from the shot coke forming petroleum vacuum resid with aggregates of asphaltenes of the sponge coke- and/or transition coke forming petroleum vacuum resid,
(iv) heating the mixture of heated sponge coke- and/or transition coke-forming petroleum vacuum resid and asphaltene derived from the shot coke forming petroleum vacuum resid of step (iii) to a delayed coking temperature, to form a free-flowing shot coke product and thermally cracked coker products;
wherein the relative proportion of aromatic solvent to water is at least 1 percent v/v and not more than 20 percent v/v relative to the aromatic solvent; and
wherein the proportion of the asphaltene derived from a shot coke-forming petroleum residual feed in the mixture of heated sponge coke- and/or transition coke forming petroleum vacuum resid and asphaltene derived from the shot coke forming petroleum vacuum resid of step (iii) is at least 5 weight percent of the sponge coke- and/or transition coke forming petroleum vacuum resid and not more than 20 weight percent.

10. A delayed coking process according to claim 9 in which the asphaltene derived from the shot coke-forming petroleum vacuum resid comprises an asphaltene with aromatic clusters containing 4 or 5 aromatic rings with an average of 1 to 2 heteroatoms per cluster.

11. A delayed coking process according to claim 10 in which the asphaltene derived from the shot coke-forming petroleum vacuum resid comprises an asphaltene with aromatic clusters containing 4 or 5 aromatic rings with an average of 1 to 2 heteroatoms per cluster, at least one of which is nitrogen.

12. A delayed coking process according to claim 10 in which the asphaltene derived from the shot coke-forming petroleum vacuum resid comprises an asphaltene with a nitrogen content of at least 0.5 wt. percent.

13. A delayed coking process according to claim 12 in which the asphaltene derived from the shot coke-forming petroleum vacuum resid comprises an asphaltene with a nitrogen content of at least 0.5 wt. percent, at least 250 ppmw of nickel plus vanadium and not more than 10.5 wt. percent hydrogen.

14. A delayed coking process according to claim 9 in which the asphaltene derived from shot coke-forming petroleum vacuum resid has the general formula:
R—Ac

where R is a hydrophobic moiety and Ac is a 4 or 5 ring aromatic cluster covalently bonded to R with an average of at least one heteroatom for each 4 or 5 ring cluster.

15. A delayed coking process according to claim 14 in which the asphaltene derived from the shot coke-forming petroleum vacuum resid has an average of 1 to 2 nitrogen atoms for each 4 or 5 ring cluster.

16. A delayed coking process according to claim 15 in which the asphaltene derived from the shot coke-forming petroleum vacuum resid has an average of 1 to 2 basic N containing aromatic heterocyclic moieties, for each 4 or 5 ring aromatic cluster.

17. A delayed coking process according to claim 9 in which the mixture of the heated sponge coke- and/or transition coke-forming petroleum vacuum resid with the asphaltene derived from shot coke-forming petroleum vacuum resid is passed from a coker combination tower to a coker furnace wherein the aggregates of the asphaltene derived from the shot coke-forming petroleum vacuum resid and the aggregates of asphaltenes of the sponge coke- and/or transition coke forming petroleum vacuum resid are formed during passage from the coker combination tower to the coker furnace.

Assignees

• Siskin Michael
• Varadaraj Ramesh
• Exxonmobil Res & Eng Co

Inventors

• Siskin Michael
• Varadaraj Ramesh

Classifications

• C10G55/04 Primary

  including at least one thermal cracking step · CPC title

• C10B57/045

  containing mineral oils, bitumen, tar or the like or mixtures thereof · CPC title

• C10B55/00

  Coking mineral oils, bitumen, tar, and the like or mixtures thereof with solid carbonaceous material (cracking oils C10G) · CPC title

• C10G9/005

  Coking (in order to produce liquid products mainly) · CPC title

• C10G2300/206

  Asphaltenes · CPC title