Catalyst structures

Patent metadata

Field	Value
Publication number	US-9340424-B2
Application number	US-201514618229-A
Country	US
Kind code	B2
Filing date	Feb 10, 2015
Priority date	Feb 12, 2010
Publication date	May 17, 2016
Grant date	May 17, 2016

Abstract

A catalyst structure suitable for use in an ammonia oxidation process is described including a plurality of shaped catalyst units supported on one or more members in a spaced relationship that allows the structure to flex.

First claim

What is claimed:

1. An ammonia oxidation process comprising the step of passing a gas mixture comprising ammonia, an oxygen containing gas and optionally a methane containing gas through a catalyst structure comprising an ammonia oxidation catalyst and/or a nitrous oxide decomposition catalyst, wherein the catalyst structure comprises a plurality of shaped catalyst units supported on one or more members in a spaced relationship that avows the structure to flex, wherein the shaped catalyst units have maximum and minimum dimensions in the range 1.5 to 20 mm, and an aspect ratio less than 3, the supporting members are metal or ceramic wires, and the separation of adjacent shaped catalyst units is in the range 1-10 mm, wherein the catalyst structure is disposed on a support mesh.

2. A process according to claim 1 wherein a particulate inert material is included in the structure.

3. A process according to claim 1 wherein two or more different catalyst particle sizes are present.

4. A process according to claim 1 wherein the shaped catalyst units have 1 to 10 through-holes.

5. A process according to claim 1 wherein the catalyst units are cylindrical pellets having 1-5 through holes.

6. A process according to claim 1 wherein the supporting members comprise steel or a platinum alloy.

7. A process according to claim 1 wherein the support members run both externally and internally with regard to the shaped catalyst units.

8. A process according to claim 1 wherein two or more linear catalyst structures, in which the catalyst units are the same or different, are connected to each other to form a mat structure.

9. A process according to claim 8 wherein two or more mat structures are arranged in layers to form a three-dimensional bed structure.

10. A process according to claim 9 wherein the support members in the mat structures are connected to each other by connectors.

11. A process according to claim 1 wherein the support mesh is made of steel, platinum, a platinum alloy or a palladium alloy, and comprises a single layer or a plurality of layers.

12. A process according to claim 1 wherein the catalyst structure is fixed to the support mesh using connectors.

13. A process according to claim 1 further comprising loose catalyst pellets.

14. A process according to claim 1 further comprising one or more precious metal ammonia oxidation catalyst gauzes.

Assignees

• Johnson Matthey Plc

Inventors

• Coupland Duncan Roy

Classifications

• Y10T428/24273

  including aperture · CPC title

• B01J2219/3086

  Filling of the packing elements into the column or vessel, e.g. using a tube · CPC title

• Y10T428/24942

  including components having same physical characteristic in differing degree · CPC title

• B01J2219/3085

  Ordered or stacked packing elements · CPC title

• B01J2219/30226

  Cone or truncated cone · CPC title