Metal oxides for selective hydrogen combustion

Patent metadata

Field	Value
Publication number	US-12157111-B2
Application number	US-202017628465-A
Country	US
Kind code	B2
Filing date	Jul 30, 2020
Priority date	Aug 2, 2019
Publication date	Dec 3, 2024
Grant date	Dec 3, 2024

Abstract

Metal oxides are provided that have selective hydrogen combustion activity while also acting as solid oxygen carriers (SOCs). The metal oxides correspond to a metal oxide core of at least one metal having multiple oxidation states that is modified with an alkali metal oxide and/or alkali metal halogen (such as an alkali metal chloride). The resulting modified metal oxide, corresponding to a solid oxygen carrier, can allow for selective combustion of hydrogen while reducing or minimizing combustion of hydrocarbons, such as within a propane dehydrogenation environment. Additionally, it has been unexpectedly found that modifying the core metal oxide with the alkali metal oxide and/or alkali metal chloride can also mitigate coke formation on the solid oxygen carrier. Methods of using such metal oxides for selective hydrogen combustion are also provided.

First claim

The invention claimed is:

1. A hydrocarbon conversion process, comprising:
contacting a hydrocarbon-containing feed with a catalyst system comprising a solid oxygen carrier under effective conditions to form a conversion effluent, the effective conditions being effective for conversion of at least a portion of the hydrocarbon-containing feed to generate hydrogen,
the solid oxygen carrier comprising:
10 wt % or more of at least one transition metal oxide comprising multiple redox states; and
one or more alkali metal salts comprising an alkali metal chloride, a molar ratio of the at least one transition metal to the alkali metal in the solid oxygen carrier being from 0.5 to 10,
wherein the solid oxygen carrier comprises an oxygen storage capacity of 0.5 wt % or more and
wherein the at least one transition metal oxide comprises an oxide of Mn, Fe, Co, Ni, Cu, or a combination thereof.

2. The method of claim 1 , wherein the alkali metal comprises K or a combination of Li and K.

3. The method of claim 1 , wherein the catalyst system further comprises a dehydrogenation catalyst, a dehydrocyclization catalyst, a reforming catalyst, or a combination thereof.

4. The method of claim 1 , wherein the alkali metal chloride comprises LiCl, NaCl, KCl, or a mixture thereof.

5. The method of claim 1 , wherein the at least one transition metal oxide comprises a single metal oxide.

6. The method of claim 1 , wherein the molar ratio of the at least one transition metal to the alkali metal in the solid oxygen carrier is from 0.5 to 8.

7. The method of claim 1 , wherein:
the at least one transition metal oxide consists essentially of an oxide of Fe,
70 wt % or more of the oxide of Fe is in the form of a single metal oxide, and
the alkali metal chloride comprises LiCI, KCl, or a mixture thereof.

8. The method of claim 1 , wherein:
the hydrocarbon-containing feed comprises a propane-containing feed,
the catalyst system further comprises a propane dehydrogenation catalyst, and
the propane dehydrogenation catalyst comprises Pt.

9. The method of claim 1 , wherein the one or more alkali metal salts further comprises an alkali metal oxide.

10. The method of claim 1 , wherein the at least one transition metal oxide comprises Mn and the alkali metal chloride comprises LiCl, KCl, or a mixture thereof.

11. The method of claim 1 , wherein the at least one transition metal oxide comprises Fe and the alkali metal chloride comprises LiCl, KCl, or a mixture thereof.

12. The method of claim 1 , wherein:
the at least one transition metal oxide consists essentially of an oxide of Mn,
the alkali metal chloride consists essentially of KCl or a mixture of KCl and LiCl, and
the molar ratio of the at least one transition metal to the alkali metal in the solid oxygen carrier is from 2.4 to 6.

13. The method of claim 1 , wherein:
the at least one transition metal oxide consists essentially of an oxide of Fe, and
the alkali metal chloride consists essentially of KCl or a mixture of KCl and LiCl.

14. The method of claim 1 , wherein:
the at least one transition metal oxide consists essentially of an oxide of Mn,
the alkali metal chloride comprises KCl or a mixture of KCl and LiCl,
the molar ratio of the at least one transition metal to the alkali metal in the solid oxygen carrier is from 2.4 to 6,
the hydrocarbon-containing feed comprises a propane-containing feed,
the catalyst system further comprises a propane dehydrogenation catalyst, and
the propane dehydrogenation catalyst comprises Pt.

15. The method of claim 1 , wherein:
the at least one transition metal oxide consists essentially of an oxide of Fe,
the alkali metal chloride comprises of KCl or a mixture of KCl and LiCl,
the hydrocarbon-containing feed comprises a propane-containing feed,
the catalyst system further comprises a propane dehydrogenation catalyst, and
the propane dehydrogenation catalyst comprises Pt.

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Bao Xiaoying

Classifications

• B01J35/40

  characterised by dimensions, e.g. grain size (in a colloidal state B01J35/23; crystallite size B01J35/77) · CPC title

• C07C2523/75

  Cobalt · CPC title

• C07C2523/745

  Iron · CPC title

• C07C2523/34

  Manganese · CPC title

• C07C5/48

  with oxygen as an acceptor · CPC title