Catalytic destruction of organohalogen compounds

• US 5,176,897 A
• Filed: 06/12/1991
• Issued: 01/05/1993
• Est. Priority Date: 05/01/1989
• Status: Expired due to Term

• Current Assignee: Alliedsignal Inc. (Honeywell International Inc.)
• Original Assignee: Alliedsignal Inc. (Honeywell International Inc.)
• Inventors: Lester, George R.
• Primary Examiner(s): Straub, Gary P.
• Assistant Examiner(s): Vanoy, Timothy C.
• Application Number:
  US07/714,364
• Time in Patent Office: 573 Days
• Field of Search: 423/239, 423/481, 423/659, 208/181, 208/182, 208/411, 502/309, 570/227, 570/229
• US Class Current: 423/659
• CPC Class Codes: A62D 2101/22 containing halogen
• CPC Class Codes: A62D 3/38 by oxidation; by combustion
• CPC Class Codes: B01D 53/8662 Organic halogen compounds
• CPC Class Codes: B01D 53/8668 Removing organic compounds not provided for in B01D53/8603 - B01D53/8665
• CPC Class Codes: B01J 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 23/64 with arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
• CPC Class Codes: B01J 23/6482 Vanadium
• CPC Class Codes: B01J 23/6527 Tungsten

Abstract

This application relates to a catalyst and a process using this catalyst to convert or destroy organic compounds including organohalogen compounds. A preferred catalyst contains as catalytic components titania, vanadium oxide, tungsten oxide, tin oxide and at least one noble metal selected from the group consisting of platinum, palladium and rhodium, characterized in that the vanadium oxide, tungsten oxide and noble metals are uniformly dispersed on the titania. The process of this invention comprises contacting the gas stream, which contains organohalogen compounds and other organic compounds, at a temperature of about 200° to about 500° C. with the catalyst described above in the presence of an oxidizing agent and water. The oxidizing agent can be oxygen or air.

Claims

1. A process for treating a gas stream containing C₁ organohalogen compounds that do not have any carbon-hydrogen bonds comprising contacting the gas stream at a temperature of about 200°

to about 500°

C. with a catalyst consisting essentially of titania and optionally at least one member of the group consisting of tungsten oxide, vanadium oxide, tin oxide and the noble metals platinum, palladium, and rhodium in the presence of an effective amount of water to convert said organohalogen compounds to carbon dioxide and haloacids.

2. The process of claim 1 where the catalyst contains tungsten oxide in a concentration, as the metal, from about 0.1 to about 20 weight percent of the titania.

3. The process of claim 1 or 2 where the catalyst contains vanadium oxide in a concentration, as the metal, from about 0.1 to about 20 weight percent of the titania.

4. The process of claim 1 where the noble metal is platinum present in a concentration from about 0.01 to about 5 weight percent of the titania.

5. The process of claim 1 where said gas stream has an H:

X atomic ratio of at least 1;

1 where X is the total concentration of halogen atoms.

6. The process of claim 1, 2, or 3 where the catalyst contains tin oxide in a concentration of about 0.1 to about 2.0 gram atoms of tin per 100 gram atoms of titanium.

7. The process of claim 1 where the titania is in the shape of spheres, granules or extrudates.

8. The process of claim 7 where the titania is in the shape of extrudates.

9. The process of claim 1 where the titania is deposited on a ceramic or metallic honeycomb carrier and is present in a concentration of about 50 to about 400 g of titania per liter of carrier volume.

10. A process for treating a gas stream containing organohalogen compounds and optionally halogen-free compounds comprising contacting the gas stream with a catalyst consisting essentially of titania and optionally at least one member of the group consisting of tungsten oxide, vanadium oxide, tin oxide, and the noble metals platinum, palladium, and rhodium at a temperature of about 200°

to about 500°

C. in the presence of an oxidizing agent and optionally water in amounts effective to convert said compounds to carbon dioxide, water, and haloacids.

11. The process of claim 10 where the catalyst contains vanadium oxide in a concentration, as the metal, from about 0.1 to about 20 weight percent of the titania.

12. The process of claim 10 where the noble metal is platinum present in a concentration from about 0.01 to about 5 weight percent of the titania.

13. The process of claim 10 or 11 where the catalyst contains tungsten oxide present in a concentration, as the metal, from about 0.1 to about 20 weight percent of the titania.

14. The process of claim 10, 11, or 13 where the catalyst contains tin oxide in a concentration of about 0.1 to about 2.0 gram atoms of tin per 100 gram atoms of titanium.

15. The process of claim 10 where the titania is in the shape of spheres, granules or extrudates.

16. The process of claim 10 where the titania is in the shape of extrudates.

17. The process of claim 10 where the titania is deposited on a ceramic or metallic honeycomb carrier and is present in a concentration of about 50 to about 400 g of titania per liter of carrier volume.

18. The process of claim 10 where said gas stream has an H:

X atomic ratio of at least 1;

1 where X is the total concentration of halogen atoms.