Reactor effluent wash to remove aromatics

Patent metadata

Field	Value
Publication number	US-10272359-B2
Application number	US-201715796718-A
Country	US
Kind code	B2
Filing date	Oct 27, 2017
Priority date	Nov 6, 2015
Publication date	Apr 30, 2019
Grant date	Apr 30, 2019

Abstract

A process is presented for the removal or aromatics from a hydrocarbon stream. The hydrocarbon stream is generated by a dehydrogenation process that generates aromatics. The process includes a two contact cooler system with the first and second contact coolers using different coolants. The second coolant is a non-aromatic hydrocarbon coolant that will absorb aromatics.

First claim

What is claimed is:

1. A process for removing aromatics from a process stream, comprising:
passing a hydrocarbon stream comprising paraffins to a dehydrogenation reactor to generate a process stream comprising olefins, paraffins, and aromatics;
passing the process stream to a first contact cooler, wherein the process stream is contacted with a first coolant to generate a first stream, wherein the first coolant comprises an aromatic solvent;
passing the first stream to a compressor to generate a second stream; and
passing the second stream to a second contact cooler, wherein the second stream is contacted with a second coolant to generate a third stream comprising olefins and paraffins,
wherein the second coolant comprises a paraffinic solvent and wherein an aromatics content of the second coolant is less than an aromatics content of the first coolant.

2. The process of claim 1 further comprising passing the third stream to a cryogenic separation unit to generate a product stream comprising olefins and paraffins.

3. The process of claim 1 wherein a temperature of the first stream is between 10° C. and 45° C. prior to being passed to the compressor.

4. The process of claim 1 wherein the first stream is compressed to a pressure between 250 kPa and 600 kPa.

5. The process of claim 1 wherein the first stream has a reduced aromatics content relative to the process stream.

6. The process of claim 5 wherein the first stream has an aromatics content below 1500 ppmw.

7. The process of claim 1 wherein the third stream has an aromatics content below 100 ppmw.

8. The process of claim 1 wherein a temperature of the third stream is between 10° C. and 45° C.

9. A process for the production of olefins from paraffins, comprising:
passing a hydrocarbon stream comprising paraffins to a dehydrogenation reactor to generate a dehydrogenation process stream comprising paraffins, olefins, and aromatics;
passing the dehydrogenation stream to a first contact cooler, wherein the dehydrogenation process stream is contacted with a first coolant comprising an aromatic solvent to cool the dehydrogenation process stream and generate a cooled dehydrogenation stream with a reduced aromatics content relative to the content of aromatics in the dehydrogenation process stream;
passing the dehydrogenation stream with a reduced aromatics content to a compressor to generate a compressed stream;
passing the compressed stream to a second contact cooler, wherein the compressed stream is contacted with a second coolant comprising a paraffinic solvent to cool the compressed stream and generate a cooled compressed stream; and
passing the cooled compressed stream to a cryogenic separation unit to generate a product stream comprising olefins and paraffins,
wherein an aromatics content of the second coolant is less than an aromatics content of the first coolant.

10. The process of claim 9 wherein a temperature of the cooled dehydrogenation stream is between 10° C. and 45° C. prior to being passed to the compressor.

11. The process of claim 9 wherein the cooled dehydrogenation stream with a reduced aromatics content is compressed to a pressure between 700 kPa and 1200 kPa.

12. The process of claim 9 wherein the cooled compressed stream has an aromatics content below 100 ppmw.

Assignees

• Uop Llc

Inventors

• Nedohin Gregory J
• Banach Mike
• Myers David N

Classifications

• C07C7/09

  by fractional condensation · CPC title

• B01D1/2846

  The compressed vapour is not directed to the same apparatus from which the vapour was taken off · CPC title

• C07C7/005

  Processes comprising at least two steps in series · CPC title

• B01D5/003 Primary

  within column(s) · CPC title

• C07C5/327

  Formation of non-aromatic carbon-to-carbon double bonds only · CPC title