Systems and methods for separating chlorine-containing species from aqueous solutions of chlorine-containing species

Patent metadata

Field	Value
Publication number	US-9718047-B2
Application number	US-201314062696-A
Country	US
Kind code	B2
Filing date	Oct 24, 2013
Priority date	Oct 24, 2013
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

Disclosed is a method for separating a chlorine-containing species from an aqueous solution of the chlorine-containing species in a catalytic hydrocarbon conversion process that includes the step of oxidizing a spent chloride-containing hydrocarbon conversion catalyst, the spent hydrocarbon conversion catalyst including a hydrocarbon residue formed thereon. The oxidizing forms a flue gas including chlorine-containing species, water, and oxides of carbon. The method further includes contacting the flue gas with a water scrubbing stream to dissolve at least a portion of the chlorine-containing species in the water scrubbing stream to form an aqueous acid solution and contacting the aqueous acid solution with a hygroscopic liquid to generate dehydrated hydrogen chloride gas. Still further, the method includes contacting the dehydrated hydrogen chloride gas with additional spent chloride-containing hydrocarbon conversion catalyst to sorb chlorine onto the additional spent chloride-containing hydrocarbon conversion catalyst.

First claim

What is claimed is:

1. A method for separating a chlorine-containing species from an aqueous solution of the chlorine-containing species in a catalytic hydrocarbon conversion process, the method comprising the steps of:
oxidizing a spent chloride-containing hydrocarbon conversion catalyst, the spent hydrocarbon conversion catalyst comprising a hydrocarbon residue formed thereon, wherein the oxidizing forms a flue gas comprising chlorine-containing species, water, and oxides of carbon;
contacting the flue gas with a water scrubbing stream to dissolve at least a portion of the chlorine-containing species in the water scrubbing stream to form a liquid aqueous acid solution;
separating and venting un-dissolved gases from the liquid aqueous acid solution wherein said un-dissolved gases comprise less than 0.01 ppm of a chloro-species;
contacting the liquid aqueous acid solution with a hygroscopic liquid to generate a dehydrated hydrogen chloride gas; and
contacting the dehydrated hydrogen chloride gas with additional spent chloride-containing hydrocarbon conversion catalyst to sorb chlorine onto the additional spent chloride-containing hydrocarbon conversion catalyst.

2. The method of claim 1 , wherein oxidizing the spent chloride-containing hydrocarbon coversion catalyst comprises combusting in the presence of oxygen gas (O 2 ).

3. The method of claim 2 , wherein the oxidizing the spent chloride-containing catalyst further comprises forming a regenerated chloride-containing catalyst.

4. The method of claim 3 , further comprising contacting the regenerated chloride-containing catalyst with a hydrocarbon feed stream in a process selected from the group consisting of: reforming, dehydrogenation, isomerization, alkylation, and transalkylation.

5. The method of claim 1 , wherein forming the flue gas comprising the chlorine-containing species comprises forming a flue gas comprising hydrogen chloride.

6. The method of claim 1 , wherein contacting with the hygroscopic liquid comprises contacting with a hygroscopic liquid selected from the group consisting of: solutions of calcium chloride (CaCl 2 ), magnesium chloride (MgCl 2 ), lithium chloride (LiCl 2 ), and lithium zinc chloride (ZnCl 2 ).

7. The method of claim 1 , wherein contacting with the hygroscopic liquid further comprises forming a diluted hygroscopic liquid.

8. The method of claim 7 , further comprising regenerating the diluted hygroscopic liquid.

9. The method of claim 1 , further comprising oxidizing the additional spent chloride-containing hydrocarbon conversion catalyst to generate additional flue gas.

10. A method for separating a chlorine-containing species from an aqueous solution of the chlorine-containing species, the method comprising the steps of:
oxidizing a spent chloride-containing hydrocarbon conversion catalyst comprising platinum/tin on chlorided alumina, the spent hydrocarbon conversion catalyst comprising a hydrocarbon residue formed thereon, wherein the oxidizing forms a flue gas comprising chlorine-containing species, water, and oxides of carbon;
contacting the flue gas with a water scrubbing stream to dissolve at least a portion of the chlorine-containing species in the water scrubbing stream to form a liquid aqueous acid solution;
separating and venting un-dissolved gasses from the liquid aqueous acid solution wherein said un-dissolved gases comprise less than 0.01 ppm of a chloro-species;
contacting the liquid aqueous acid solution with a hygroscopic liquid to generate a dehydrated hydrogen chloride gas; and
contacting the dehydrated hydrogen chloride gas with the oxidized chloride-containing hydrocarbon conversion catalyst to sorb chlorine onto the oxidized chloride-containing hydrocarbon conversion catalyst.

11. The method of claim 10 , wherein oxidizing comprises combusting the hydrocarbon residue in the presence of oxygen gas (O 2 ).

12. The method of claim 11 , wherein oxidizing comprises forming a regenerated chloride-containing catalyst.

13. The method of claim 12 , further comprising contacting the regenerated chloride-containing catalyst with a hydrocarbon feed stream.

14. The method of claim 10 , wherein the chlorine-containing species comprises hydrogen chloride.

15. The method of claim 10 , wherein the hygroscopic liquid is selected from the group consisting of: solutions of calcium chloride (CaCl 2 ), magnesium chloride (MgCl 2 ), lithium chloride (LiCl 2 ), and zinc chloride (ZnCl 2 ).

16. The method of claim 10 , further comprising forming a diluted hygroscopic liquid.

17. The method of claim 1 , further comprising contacting the dehydrated hydrogen chloride gas with additional spent chloride-containing hydrocarbon conversion catalyst.

Assignees

• Uop Llc

Inventors

• Moser Mark D
• Wegerer David A

Classifications

• Y02P20/584

  Recycling of catalysts · CPC title

• B01J38/02

  Heat treatment · CPC title

• C10K1/003

  of acid contaminants, e.g. acid gas removal · CPC title

• B01J38/18

  with subsequent reactive gas treating · CPC title

• B01J38/12

  Treating with free oxygen-containing gas · CPC title