Compositions for high temperature catalysis

Patent metadata

Field	Value
Publication number	US-11318447-B2
Application number	US-201916512752-A
Country	US
Kind code	B2
Filing date	Jul 16, 2019
Priority date	Jul 30, 2018
Publication date	May 3, 2022
Grant date	May 3, 2022

Abstract

Ceramic compositions with catalytic activity are provided, along with methods for using such catalytic ceramic compositions. The ceramic compositions correspond to compositions that can acquire increased catalytic activity by cyclic exposure of the ceramic composition to reducing and oxidizing environments at a sufficiently elevated temperature. The ceramic compositions can be beneficial for use as catalysts in reaction environments involving swings of temperature and/or pressure conditions, such as a reverse flow reaction environment. Based on cyclic exposure to oxidizing and reducing conditions, the surface of the ceramic composition can be converted from a substantially fully oxidized state to various states including at least some dopant metal particles supported on a structural oxide surface.

First claim

The invention claimed is:

1. A method for reforming a hydrocarbon-containing stream, comprising:
exposing an initial ceramic composition comprising 0.1 wt % or more of at least one dopant metal oxide and 50 wt % to 99 wt % of one or more structural oxides, to a reducing environment comprising a temperature of 500° C. to 1400° C. to form a catalyst composition comprising dopant metal particles supported on the one or more structural oxides, the one or more dopant metals corresponding to dopant metal oxides having a Gibbs free energy of formation at 800° C. that is greater than a Gibbs free energy of formation at 800° C. for the one or more structural oxides by 200 kJ/mol or more, the particles of the one or more dopant metals having an average characteristic length of 10 μm or less, the dopant metal oxide comprising an oxide of Rh, Ru, Pd, Pt, Ir, or a combination thereof;
exposing the catalyst composition to an oxidizing environment comprising a temperature of 500° C. to 1400° C.;
exposing a hydrocarbon-containing stream to the catalyst composition in the presence of at least one of H 2 O and CO 2 under reforming conditions comprising a temperature of 500° C. or more to form a reformed product comprising H 2 , the exposing the hydrocarbon-containing stream to the catalyst composition being performed after the exposing the catalyst composition to the oxidizing environment; and
exposing the catalyst composition to a stream comprising fuel and 0.1 vol % or more of O 2 under combustion conditions to heat an environment for the catalytic composition to a temperature of 500° C. or more.

2. The method of claim 1 , wherein the one or more structural oxides comprise at least one mixed structural oxide phase.

3. The method of claim 1 , wherein the catalyst composition further comprises a mixed oxide phase including an oxide of the one or more dopant metals and at least one structural oxide.

4. A method for reforming a hydrocarbon-containing stream, comprising:
exposing an initial ceramic composition comprising 1.0 wt % or more of Ni in an oxide form and 50 wt % to 99 wt % of one or more structural oxides, the one or more structural oxides comprising Al 2 O 3 , to a reducing environment comprising a temperature of 500° C. to 1400° C. to form a catalyst composition comprising Ni particles supported on Al 2 O 3 ;
exposing the catalyst composition to an oxidizing environment comprising a temperature of 500° C. to 1400° C.;
exposing a hydrocarbon-containing stream to the catalyst composition in the presence of at least one of H 2 O and CO 2 under reforming conditions comprising a temperature of 800° C. or more to form a reformed product comprising H 2 , the exposing the hydrocarbon-containing stream to the catalyst composition being performed after the exposing the catalyst composition to the oxidizing environment; and
exposing the catalyst composition to a stream comprising fuel and 0.1 vol % or more of O 2 under combustion conditions to heat an environment for the catalyst catalytic composition to a temperature of 800° C. or more.

5. The method of claim 4 , wherein exposing the initial ceramic composition to the reducing environment comprises exposing the initial ceramic composition to a hydrocarbon-containing stream in the presence of at least one of H 2 O and CO 2 under reforming conditions comprising a temperature of 500° C. or more.

6. The method of claim 4 , wherein exposing the catalyst composition to an oxidizing environment comprises exposing the catalyst composition to a stream comprising 0.1 vol % or more of O 2 at a regeneration temperature of 500° C. or more for a regeneration time period.

7. The method of claim 4 , i) wherein the catalyst composition comprises a monolith having a cell density of more than 900 cells per square inch, ii) wherein the catalyst composition comprises a honeycomb monolith, iii) wherein the initial composition is formed by extrusion, or iv) a combination of two or more if i), ii), and iii).

8. The method of claim 4 , wherein the catalyst composition comprises a volumetric heat capacity of 140 kJ/cm 3 or more.

9. The method of claim 4 , wherein the catalyst composition further comprises NiO, NiAl 2 O 4 , or a combination thereof.

10. The method of claim 4 , wherein the initial ceramic composition comprises 40 wt % or more Al 2 O 3 .

11. The method of claim 4 , wherein the initial ceramic composition comprises an initial ceramic composition sintered at a temperature of 1200° C. or higher.

12. A method for reforming a hydrocarbon-containing stream, comprising:
performing a cyclic reforming process, the cyclic reforming process comprising:
introducing a hydrocarbon-containing stream into a first end of a reactor comprising a monolith comprising a catalyst composition, the catalyst composition comprising 0.1 wt % or more of dopant metal particles supported on 50 wt % to 99 wt % of one or more structural oxides, the one or more dopant metals corresponding to dopant metal oxides having a Gibbs free energy of formation at 800° C. that is greater than a Gibbs free energy of formation at 800° C. for the one or more structural oxides by 200 kJ/mol or more, the particles of the one or more dopant metals having an average characteristic length of 10 μm or less, the dopant metal oxide comprising an oxide of Rh, Ru, Pd, Pt, Ir, or a combination thereof;
exposing the hydrocarbon-containing stream to the catalyst composition in the presence of at least one of H 2 O and CO 2 under reforming conditions comprising a temperature of 800° C. or more to form a reformed product comprising H 2 ;
withdrawing at least a portion of the reformed product from a first location different from the first end of the reactor;
introducing a regeneration stream comprising fuel and a stream comprising O 2 into the reactor, at least a portion of the stream comprising fuel, at least a portion of the stream comprising O 2 , or a combination thereof being introduced into a second end of the reactor;
combusting the stream comprising fuel and the stream comprising oxygen under combustion conditions to form a combustion product stream;
exposing the combustion product stream to the catalyst composition to transfer heat to the catalyst composition; and
withdrawing at least a portion of the combustion product stream from the reactor.

13. The method of claim 12 , wherein the catalyst composition further comprises a mixed oxide phase including an oxide of the one or more dopant metals and at least one structural oxide.

14. A method for reforming a hydrocarbon-containing stream, comprising:
performing a cyclic reforming process, the cyclic reforming process comprising:
introducing a hydrocarbon-containing stream into a first end of a reactor comprising a monolith comprising a catalyst composition, the catalyst composition comprising 1.0 wt % or more of Ni particles, NiO, NiAl 2 O 4 , or a combination thereof, supported on 50 wt % to 99 wt % of one or more structural oxides, the one or more structural oxides comprising Al 2 O 3 ;
exposing the hydrocarbon-containing stream to the catalyst composition in the presence of at least one of H 2 O and CO 2 under reforming conditions comprising a peak temperature of 800° C. or more to form a reformed product comprising H 2 ;
withdrawing at least a portion of the reformed product from a first location different from the first end of the reactor;
introducing a regeneration stream comprising fuel and a stream comprising O 2 into the reactor, at least a portion of the stream comprising fuel and/or the stream comprising O 2 being introduced into a second end of the reactor;
combusting the stream comprisi

Assignees

• Exxonmobil Res & Eng Co

Inventors

• Ide Matthew S
• Chun Changmin
• Skoulidas Anastasios I

Classifications

• B01J35/56

  Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional [3D] monoliths · CPC title

• B01J21/04

  Alumina · CPC title

• B01J38/02

  Heat treatment · CPC title

• C01B3/40 Primary

  characterised by the catalyst · CPC title

• B01J23/78 Primary

  with alkali- or alkaline earth metals · CPC title