Processes and apparatuses for Olefin saturation in an aromatics complex

Patent metadata

Field	Value
Publication number	US-10647932-B2
Application number	US-201815987871-A
Country	US
Kind code	B2
Filing date	May 23, 2018
Priority date	Dec 16, 2015
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

Process and apparatuses for producing benzene and para-xylene from a reformate stream is provided. The process comprises separating the reformate stream to provide a first stream comprising C 4 and lighter hydrocarbons and a second stream comprising aromatic hydrocarbons. The second steam is provided to a reformate splitter to provide a reformate bottoms stream comprising C 8+ aromatic hydrocarbons and a reformate overhead stream comprising C 7− aromatic hydrocarbons. The reformate overhead stream is passed to an aromatics extraction unit to provide an aromatics extract stream comprising benzene and toluene and a raffinate stream comprising non-aromatic hydrocarbons. The reformate bottoms stream and one of the first stream and the raffinate stream is passed to an olefin reduction zone, wherein the reformate bottoms stream and one of the first stream and the raffinate stream are contacted with an olefin saturation catalyst under olefin saturation conditions to produce an olefin-treated reformate stream.

First claim

The invention claimed is:

1. A process for producing benzene and para-xylene from a reformate stream, wherein the process comprises:
a) separating the reformate stream to provide a first stream comprising C 4 and lighter hydrocarbons and a second stream comprising aromatic hydrocarbons;
b) providing the second stream to a reformate splitter to provide a reformate bottoms stream comprising C 8+ aromatic hydrocarbons and a reformate overhead stream comprising C 7− aromatic hydrocarbons;
c) passing the reformate overhead stream to an aromatics extraction unit to provide an aromatics extract stream comprising benzene and toluene and a raffinate stream comprising non-aromatic hydrocarbons;
d) passing the reformate bottoms stream and one of the first stream and the raffinate stream to an olefin reduction zone, wherein the reformate bottoms stream and one of the first stream and the raffinate stream are contacted with an olefin saturation catalyst under olefin saturation conditions to produce an olefin-treated reformate stream; and
e) recovering a para-xylene product stream from the olefin-treated reformate stream.

2. The process of claim 1 further comprising providing a naphtha stream to a hydrotreating zone to produce a hydrotreated naphtha stream and passing at least a portion of the hydrotreated naphtha stream to a catalytic reforming unit, wherein said at least the portion of the hydrotreated naphtha stream is contacted with a reforming catalyst under reforming conditions to produce the reformate stream comprising aromatic hydrocarbons and C 4 and lighter hydrocarbons.

3. The process of claim 2 further comprising passing the hydrotreated naphtha stream and a hydrocracked heavy naphtha stream to a naphtha splitter to provide a light naphtha stream and a heavy naphtha stream before passing said at least the portion of the hydrotreated naphtha stream to the catalytic reforming unit, and wherein passing said at least the portion of the hydrotreated naphtha stream to the catalytic reforming unit comprises passing the heavy naphtha stream to the catalytic reforming unit.

4. The process of claim 1 wherein recovering the para-xylene product stream from the olefin-treated reformate stream comprises passing the olefin-treated reformate stream to an olefin product stripper column to provide an overhead raffinate product stream and a bottoms stripper stream and recovering the para-xylene product stream from the bottoms stripper stream.

5. The process of claim 4 wherein recovering the para-xylene product stream from the bottoms stripper stream comprises passing the bottoms stripper stream to a xylene fractionation column to produce an overhead xylene stream and a xylene fractionator bottoms stream rich in C 9 and heavier alkylaromatic hydrocarbons and recovering the para-xylene product stream from the overhead xylene stream.

6. The process of claim 1 wherein recovering the para-xylene product stream from the overhead xylene stream comprises passing the overhead xylene stream to a para-xylene column to recover the para-xylene product stream, a mixed xylenes stream, and a xylene raffinate stream.

7. The process of claim 6 further comprising contacting the mixed xylenes stream with an isomerization catalyst in the presence of hydrogen in an isomerization column under isomerization conditions to produce an isomerization product stream and subsequently recovering para-xylene from the isomerization product stream.

8. The process of claim 5 further comprising passing the xylene fractionator bottoms stream to a heavy aromatics column to separate heavy aromatics from C 9 and C 10 alkylaromatics recovered as a heavy aromatics column overhead stream.

9. The process of claim 8 further comprising passing the aromatics extract stream comprising benzene and toluene to a benzene column forming a benzene-enriched stream and a benzene column bottoms stream, and passing the benzene column bottoms stream to a toluene column forming a toluene-enriched stream and a toluene column bottoms stream, and recovering the benzene-enriched stream and the toluene-enriched stream.

10. The process of claim 9 further comprising passing the heavy aromatics column overhead stream and the toluene-enriched stream to an transalkylation zone to provide a transalkylated stream comprising benzene and xylene.

11. The process of claim 10 further comprising passing the transalkylated stream to a transalkylation stripper to recover a transalkylation stripper bottoms stream comprising benzene and toluene and passing the transalkylation stripper bottoms stream to the benzene column and subsequently to the toluene column.

12. The process of claim 11 further comprising passing a toluene column bottoms stream from the toluene column to the xylene fractionation column.

13. A process for producing benzene and para-xylene from a reformate stream, wherein the process comprises:
a) separating the reformate stream to provide a first stream comprising C 4 and lighter hydrocarbons and a second stream comprising aromatic hydrocarbons;
b) providing the second stream to a reformate splitter to provide a reformate bottoms stream comprising C 8+ aromatic hydrocarbons and a reformate overhead stream comprising C 7− aromatic hydrocarbons;
c) passing the reformate overhead stream to an aromatics extraction unit to provide an aromatics extract stream comprising benzene and toluene and a raffinate stream comprising non-aromatic hydrocarbons;
d) passing the aromatics extract stream to a benzene column to forming a benzene-enriched stream and a benzene column bottoms stream, and passing the benzene column bottoms stream to a toluene column forming a toluene-enriched stream and a toluene column bottoms stream, and recovering the benzene-enriched stream and the toluene-enriched stream;
e) passing the reformate bottoms stream and one of the first stream and the raffinate stream to an olefin reduction zone, wherein the reformate bottoms stream and one of the first stream and the raffinate stream are contacted with an olefin saturation catalyst under olefin saturation conditions to produce an olefin-treated reformate stream;
f) passing the olefin treated reformate stream to an olefin product stripper column to a provide an overhead raffinate product stream and a bottoms stripper stream; and
g) recovering para-xylene from the bottoms stripper streams.

14. The process of claim 13 further comprising providing a naphtha stream to a hydrotreating zone to produce a hydrotreated naphtha stream and passing the hydrotreated naphtha stream to a catalytic reforming unit, wherein said hydrotreated naphtha stream is contacted with a reforming catalyst under reforming conditions to produce the reformate stream comprising aromatic components and C 4 and lighter hydrocarbons.

15. The process of claim 13 , wherein the recovery of para-xylene comprises passing the bottoms stripper stream to a xylene fractionation column to produce an overhead xylene stream and a xylene fractionator bottoms stream rich in C 9 and heavier alkylaromatic hydrocarbons and passing the overhead xylene stream to a para-xylene column to recover a para-xylene product stream.

16. The process of claim 15 further comprising passing the xylene fractionator bottoms stream to a heavy aromatics column to separate heavy aromatics from C 9 and C 10 alkylaromatics recovered as a heavy aromatics column overhead stream.

17. The process of claim 16 further comprising passing the heavy aromatics column overhead stream and the toluene-enriched stream to an transalkylation zone to provide a transalkylat

Assignees

• Uop Llc

Inventors

• Kalra Jalesh
• Noe Robert J L

Classifications

• C10G53/02

  plural serial stages only · CPC title

• C10G67/0418

  The hydrotreatment being a hydrorefining · CPC title

• C10G67/00

  Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only · CPC title

• C07C6/126 Primary

  of more than one hydrocarbon · CPC title

• C10G2400/30

  Aromatics · CPC title