Process and apparatus for selectively hydrogenating naphtha

Patent metadata

Field	Value
Publication number	US-2016102258-A1
Application number	US-201414511877-A
Country	US
Kind code	A1
Filing date	Oct 10, 2014
Priority date	Oct 10, 2014
Publication date	Apr 14, 2016
Grant date	—

Abstract

The process and apparatus of the present invention selectively hydrogenates a heavier olefinic naphtha stream in an upstream catalyst bed and the hydrogenated effluent and a lighter olefinic naphtha stream in a downstream catalyst bed. The heavier di-alkenes are less re-active and are contacted with more hydrogenation catalyst than the lighter di-alkenes which are more re-active.

First claim

1 . A process for selective hydrogenation comprising:
mixing hydrogen with a heavy naphtha stream containing di-alkenes and having a first end point; selectively hydrogenating said heavy naphtha stream over a hydrogenation catalyst to produce a heavy hydrogenated naphtha stream with a lower concentration of di-alkenes; adding a lighter naphtha stream containing di-alkenes and having a second end point that is lower than the first end point to the heavy hydrogenated naphtha stream; and selectively hydrogenating the heavy hydrogenated naphtha stream and the lighter naphtha stream over hydrogenation catalyst to produce a product naphtha stream depleted of di-alkenes.

2 . The process of claim 1 further including separating a naphtha stream into said lighter naphtha stream and said heavy naphtha stream.

3 . The process of claim 2 wherein the cut point between said lighter naphtha stream and said heavy naphtha stream is between about 55° and about 75° C.

4 . The process of claim 1 further comprising hydrodesulfurizing said product naphtha stream over a hydrodesulfurization catalyst.

5 . The process of claim 2 further comprising contacting said naphtha stream with an alkaline stream to produce sulfides before the separation step.

6 . The process of claim 2 further comprising separating said naphtha stream into a light naphtha stream, an intermediate naphtha stream which is said lighter naphtha stream, and said heavy naphtha stream.

7 . The process of claim 6 further comprising selectively hydrogenating said light naphtha stream separately from selectively hydrogenating the heavy naphtha stream and the lighter hydrogenated naphtha stream to provide a hydrogenated light naphtha stream.

8 . The process of claim 7 further comprising refluxing said hydrogenated light naphtha stream to said separation step.

9 . The process of claim 6 further comprising contacting said light naphtha stream with an alkaline stream to produce sulfides.

10 . A process for selectively hydrogenating naphtha comprising:
separating a naphtha stream into a light naphtha stream, an intermediate naphtha stream, and a heavy naphtha stream; mixing hydrogen with said heavy naphtha stream containing di-alkenes and having a first end point; selectively hydrogenating said heavy naphtha stream over a first bed of hydrogenation catalyst to produce a heavy hydrogenated naphtha stream with a lower concentration of di-alkenes; adding said lighter naphtha stream containing di-alkenes and have a second end point that is lower than the first end point to said heavy hydrogenated naphtha stream; and selectively hydrogenating the heavy naphtha stream and the lighter hydrogenated naphtha stream over a second bed of hydrogenation catalyst to produce a product naphtha stream depleted of di-alkenes.

11 . The process of claim 10 wherein the cut point between said intermediate naphtha stream and said heavy naphtha stream is between about 55° and about 75° C.

12 . The process of claim 10 further comprising hydrodesulfurizing said product naphtha stream over a hydrodesulfurization catalyst.

13 . The process of claim 10 further comprising mixing said light naphtha stream with hydrogen and selectively hydrogenating said light naphtha stream to produce a hydrogenated light naphtha stream.

14 . The process of claim 13 further comprising refluxing said hydrogenated light naphtha stream to said separation step.

15 . The process of claim 10 further comprising contacting said naphtha stream with an alkaline stream to produce sulfides prior to said separation step.

16 . The process of claim 10 further comprising contacting said light naphtha stream with an alkaline stream to produce sulfides.

17 . A process for selectively hydrogenating naphtha comprising:
separating a naphtha stream into a lighter naphtha stream and a heavy naphtha stream; mixing hydrogen with said heavy naphtha stream containing di-alkenes and having a first end point; selectively hydrogenating said heavy naphtha stream over a first bed of hydrogenation catalyst to produce a heavy hydrogenated naphtha stream with a lower concentration of di-alkenes; adding a lighter naphtha stream containing di-alkenes and having a second end point that is lower than the first end point to the heavy hydrogenated naphtha stream; and selectively hydrogenating the lighter naphtha stream and the heavy hydrogenated naphtha stream over a second bed of hydrogenation catalyst to produce a product naphtha stream depleted of di-alkenes.

18 . The process of claim 17 further comprising contacting said naphtha stream with an alkaline stream to produce sulfides prior to said separation step.

19 . The process of claim 17 further comprising separating said naphtha stream into a light naphtha stream, an intermediate naphtha stream which is said lighter naphtha stream, and said heavy naphtha stream.

20 . The process of claim 17 further comprising selectively hydrogenating said light naphtha stream separately from selectively hydrogenating said heavy naphtha stream and said lighter hydrogenated naphtha stream to provide a hydrogenated light naphtha stream.

Assignees

• Uop Llc

Inventors

• Kumar Avnish
• Zink Steven F
• Banerjee Soumendra M

Classifications

• C10G2300/1044

  Heavy gasoline or naphtha having a boiling range of about 100 - 180 °C · CPC title

• C10G45/32 Primary

  Selective hydrogenation of the diolefin or acetylene compounds · CPC title

• C10G65/02 Primary

  plural serial stages only · CPC title

• C10G65/06

  at least one step being a selective hydrogenation of the diolefins · CPC title

• C10G65/00

  Treatment of hydrocarbon oils by two or more hydrotreatment processes only · CPC title