Distillate hydrocracking process with a reverse isomerization step to increase a concentration of n-paraffins

Patent metadata

Field	Value
Publication number	US-12570588-B2
Application number	US-202318320351-A
Country	US
Kind code	B2
Filing date	May 19, 2023
Priority date	May 19, 2023
Publication date	Mar 10, 2026
Grant date	Mar 10, 2026

Abstract

In accordance with one or more embodiments of the present disclosure, a process for treating a diesel feedstock to convert diesel to component-paraffins includes hydrodesulfurizing and hydrodenitrogenizing the diesel feedstock to reduce a sulfur content of the diesel feedstock and a nitrogen content of the diesel feedstock; hydrocracking the hydrodesulfurized and hydrodenitrogenized diesel feedstock over a metal-containing diesel hydrocracking catalyst comprising at least one zeolite to produce a hydrocrackate fraction; separating the hydrocrackate fraction into a first stream enriched in n-paraffins and a second stream enriched in iso-paraffins and naphthenes; and reverse isomerizing at least a portion of the second stream over an isomerization catalyst to convert at least a portion of the iso-paraffins to n-paraffins, producing a reverse isomerate fraction.

First claim

What is claimed is:

1 . A process for treating a diesel feedstock to convert diesel to n-paraffins, comprising:
hydrodesulfurizing and hydrodenitrogenizing the diesel feedstock to reduce a sulfur content of the diesel feedstock and a nitrogen content of the diesel feedstock; hydrocracking the hydrodesulfurized and hydrodenitrogenized diesel feedstock over a metal-containing diesel hydrocracking catalyst comprising at least one zeolite to produce a hydrocrackate fraction; separating the hydrocrackate fraction into a first stream enriched in n-paraffins and a second stream enriched in iso-paraffins and naphthenes; and reverse isomerizing at least a portion of the second stream over an isomerization catalyst to convert at least a portion of the iso-paraffins to n-paraffins, producing a reverse isomerate fraction.

2 . The process of claim 1 , further comprising separating the reverse isomerate fraction into a third stream enriched in n-paraffins and a fourth stream enriched in iso-paraffins and naphthenes.

3 . The process of claim 2 , further comprising recycling at least a portion of the reverse isomerate fraction.

4 . The process of claim 2 , further comprising combining at least a portion of the hydrocrackate fraction and at least a portion of the reverse isomerate fraction.

5 . The process of claim 2 , wherein the third stream comprises at least a portion of the first stream from the hydrocrackate fraction and n-paraffins from the reverse isomerate fraction.

6 . The process of claim 2 , wherein the third stream comprises greater than or equal to 80 weight percent n-paraffins, based on the total weight of the third stream.

7 . The process of claim 2 , wherein the third stream comprises greater than or equal to 30 weight percent n-paraffins, based on the total weight of the hydrocrackate fraction.

8 . The process of claim 2 , further comprising steam cracking at least a portion of the first stream, at least a portion of the third stream, or at least a portion of the first stream and at least a portion of the third stream to convert at least a portion of the n-paraffins to light olefins.

9 . The process of claim 2 , wherein the fourth stream comprises at least a portion of the second stream from the hydrocrackate fraction and iso-paraffins from the reverse isomerate fraction.

10 . The process of claim 2 , further comprising adding at least a portion of the second stream, at least a portion of the fourth stream, or at least a portion of the second stream and at least a portion of the fourth stream to a gasoline pool.

11 . The process of claim 2 , further comprising adding at least a portion of the second stream, at least a portion of the fourth stream, or at least a portion of the second stream and at least a portion of the fourth stream to a feedstock for a fluid catalytic cracking process or a catalytic reforming process.

12 . The process of claim 11 , wherein the fluid catalytic cracking process converts at least a portion of the feedstock for the fluid catalytic cracking process to propylene.

13 . The process of claim 1 , further comprising removing at least a portion of C 1 -C 4 hydrocarbons from the reverse isomerate fraction.

14 . The process of claim 1 , wherein the sulfur content of the diesel feedstock is reduced to less than or equal to 500 ppm by weight in the hydrodesulfurizing step.

15 . The process of claim 1 , wherein the diesel feedstock boils at a temperature from 150° C. to 420° C.

16 . The process of claim 1 , wherein the metal-containing diesel hydrocracking catalyst comprises a noble metal selected from the group consisting of platinum, palladium, ruthenium, gold, and a combination of two or more thereof.

17 . The process of claim 1 , wherein the hydrocracking occurs in a hydrocracking reactor that operates at a temperature from 280° C. to 400° C., at pressure less than or equal to 60 bars, a hydrogen-to-oil ratio of from 500 StLt/Lt to 1000 StLt/Lt, and at a liquid hourly space velocity from 0.5 per hour to 5 per hour.

18 . The process of claim 1 , wherein the at least one zeolite comprises at least one of an ultra-stable Y-type (USY) zeolite, a post modified USY zeolite, a zeolite beta (BEA zeolite), an MFI zeolite, or an MOR zeolite.

19 . The process of claim 1 , wherein the isomerization catalyst comprises platinum, chlorinated alumina, sulfated zirconia, mordenite framework zeolite (MOR), or combinations of two or more thereof.

20 . The process of claim 1 , wherein the isomerizing occurs in a reactor that operates at a temperature from 80° C. to 300° C., at pressure of from 15 bars to 35 bars, and at a liquid hourly space velocity from 1 per hour to 2 per hour.

Assignees

• Saudi Arabian Oil Co

Inventors

• Koseoglu Omer Refa
• Punetha Ashok Kumar

Classifications

• C10G2400/20

  C2-C4 olefins · CPC title

• B01D3/10

  Vacuum distillation (B01D3/12 takes precedence) · CPC title

• C10G2300/202

  Heteroatoms content, i.e. S, N, O, P · CPC title

• C10G2400/28

  Propane and butane · CPC title

• B01D3/143

  by two or more of a fractionation, separation or rectification step · CPC title