Regeneration loop clean-up

Patent metadata

Field	Value
Publication number	US-9517983-B2
Application number	US-201414332485-A
Country	US
Kind code	B2
Filing date	Jul 16, 2014
Priority date	Jul 16, 2014
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

A process is disclosed for removing contaminants from an olefin stream, comprising passing the contaminated olefin stream through a first adsorbent in a thermal swing adsorption process to produce a relatively pure olefin product stream, and a regenerating gas stream containing the contaminants, passing the contaminated regenerating gas stream through a pressure swing adsorption process to yield a relatively pure regenerating gas stream, which can be redirected to the thermal swing adsorption process for regenerating the adsorbent therein.

First claim

The invention claimed is:

1. A process for removing contaminants from an olefin feed comprising:
a) directing said olefin feed into contact with a first particulate adsorbent bed capable of removing said contaminants from said olefin feed, and producing an olefin product containing less contaminants than said feed;
b) heating said first adsorbent bed and directing a regenerating gas through the first adsorbent bed to desorb said contaminants from said adsorbent, and produce a regeneration gas effluent containing said contaminants; and
c) directing said regeneration gas effluent through a second particulate adsorbent bed, so as to adsorb and remove said contaminants from said regeneration gas effluent and produce a regenerating gas product having a reduced level of contaminants than said regeneration gas effluent;
wherein said contaminants comprise organic oxygenates, inorganic sulfur compounds, organic sulfur compounds, or a mixture thereof.

2. The process of claim 1 , wherein said first particulate adsorbent bed comprises an alumina, a zeolite, a composite of alumina-zeolite, or alumina, zeolite, or composite of alumina-zeolite doped with an oxide of alkali or alkaline-earth metals.

3. The process of claim 2 , wherein said first adsorbent bed comprises zeolite 3A, 4A, 5A, 13X or Na Y or combinations of said zeolites with alumina.

4. The process of claim 1 , wherein said regenerating gas is nitrogen or fuel gas.

5. The process of claim 1 , wherein said contaminants comprise organic oxygenates.

6. The process of claim 1 , wherein said contaminants comprise inorganic sulfur compounds or organic sulfur compounds.

7. The process of claim 1 , wherein said contaminants comprise up to 500 ppm of said olefin feed.

8. The process of claim 1 , comprising desorbing the contaminants from said second adsorbent bed by reducing the pressure in said second adsorbent bed and form a low pressure waste gas containing said contaminants.

9. The process of claim 8 , wherein said second adsorbent bed comprises alumina.

10. The process of claim 1 , wherein said regenerating gas effluent containing said contaminants is cooled prior to contact with said second particulate adsorbent.

11. The process of claim 10 , wherein water is removed from said regenerating gas effluent during said cooling.

12. The process of claim 1 , wherein said first adsorbent bed is heated by heating said regenerating gas and passing said regenerating gas in contact with said first adsorbent bed.

13. The process of claim 12 , wherein said regenerating gas is heated to a temperature of from about 200-500° C.

14. The process of claim 1 , wherein said regenerating gas effluent containing said contaminants is pressurized to a pressure of at least 50 psia prior to contact with said second adsorbent bed.

15. The process of claim 1 , wherein the ratio of adsorption pressure to desorption pressure in said second adsorption bed is at least 2.0.

16. The process of claim 1 , comprising directing at least a portion of said regenerating gas product to said first adsorbent bed containing adsorbed contaminants.

17. The process of claim 1 , wherein said olefin feed stream contains at least about 50 wt. % ethylene, propylene, butylene, or a mixture thereof.

18. The process of claim 17 , wherein said olefin feed stream comprises at least 90 wt. % of ethylene, propylene, butylene, or a mixture thereof.

19. The process of claim 16 , wherein said regenerating gas is nitrogen or fuel gas.

Assignees

• Basf Corp

Inventors

• Dolan William

Classifications

• B01D2253/108

  Zeolites · CPC title

• B01D53/0423

  Beds in columns · CPC title

• B01D2253/104

  Alumina · CPC title

• B01D2259/40086

  by using a purge gas (B01D2259/4009 takes precedence) · CPC title

• B01D2256/24

  Hydrocarbons · CPC title