Methanol production from methane utilizing a supported chromium catalyst

Patent metadata

Field	Value
Publication number	US-12134591-B2
Application number	US-202318494846-A
Country	US
Kind code	B2
Filing date	Oct 26, 2023
Priority date	Oct 31, 2022
Publication date	Nov 5, 2024
Grant date	Nov 5, 2024

Abstract

Processes for converting methane into methanol are disclosed in which methane, water, and a supported chromium (VI) catalyst are contacted with a light beam at a wavelength in the UV-visible spectrum in an oxidizing atmosphere in a single reactor to form a reaction product comprising methanol, followed by discharging a reactor effluent containing the reaction product from the single reactor, and then separating methanol from the reaction product. Processes to produce methanol using additional reactors also are described, as well as related methanol production systems.

First claim

We claim:

1. A process for converting methane into methanol, the process comprising:
(i) contacting methane, water, and a supported chromium catalyst comprising chromium in a hexavalent oxidation state with a light beam at a wavelength in the UV-visible spectrum in an oxidizing atmosphere in a single reactor to form a reaction product comprising methanol, wherein:
the oxidizing atmosphere comprises air; and
a molar ratio of molecular oxygen in the oxidizing atmosphere to chromium of the supported chromium catalyst is at least 2:1;
(ii) discharging a reactor effluent containing the reaction product from the single reactor; and
(iii) separating methanol from the reaction product.

2. The process of claim 1 , wherein the supported chromium catalyst has a pore volume from 0.1 to 1 mL/g and a BET surface area from 750 to 2000 m 2 /g.

3. The process of claim 1 , wherein:
the supported chromium catalyst comprises a chromium/silica catalyst; and
the single reactor is a fluidized bed reactor.

4. The process of claim 1 , wherein the supported chromium catalyst contains from 1 to 10 wt. % chromium, based on the weight of the supported chromium catalyst.

5. The process of claim 1 , wherein;
the light beam is from a blue light source or a UV light source;
the light beam comprises wavelengths above 350 nm and below 450 nm;
the methane and the supported chromium catalyst are irradiated with an illuminance of at least 10,000 lux; or
any combination thereof.

6. The process of claim 1 , wherein:
a molar ratio of methane to chromium of the supported chromium catalyst is at least 10:1; and
a molar ratio of water to chromium of the supported chromium catalyst is at least 5:1.

7. The process of claim 1 , wherein step (i) is conducted at:
a temperature from 20° C. to 250° C.;
a pressure from 10 to 200 psig; and
an average contact time of the supported chromium catalyst with methane from 3 see to 150 sec.

8. The process of claim 1 , wherein a molar yield of methanol is from 0.25 to 100 moles of the methanol per mole of chromium (VI) of the supported chromium catalyst.

9. The process of claim 1 , further comprising a step of condensing to separate the reaction product from the reactor effluent, and wherein separating methanol from the reaction product comprises distillation.

10. The process of claim 1 , further comprising a step of recycling unreacted methane and oxygen from the reactor effluent to the reactor.

11. The process of claim 1 , further comprising a step of calcining the supported chromium catalyst after step (i) to regenerate at least a portion of the supported chromium catalyst comprising chromium in a hexavalent oxidation state.

12. The process of claim 1 , wherein the single reactor is a fluidized bed reactor.

13. The process of claim 1 , wherein:
step (i) comprises contacting methane with a fluidized bed of the supported chromium catalyst while irradiating.

14. The process of claim 1 , wherein the single reactor has one or more immersion lamps as a source of the light beam attached to a top, attached to a bottom, attached to a wall, or positioned in a wall of the single reactor, or any combination thereof.

15. The process of claim 1 , wherein the single reactor has one or more internal light sources of the light beam, the internal light sources entering through one or more ports positioned at a wall of the single reactor.

16. The process of claim 1 , wherein water is added in step (i) via steam injection into the single reactor.

17. The process of claim 1 , wherein the reactor effluent comprises methanol, unreacted methane, and a reaction by-product comprising formic acid.

18. The process of claim 17 , wherein the process further comprises a step of neutralizing formic acid or converting formic acid to a non-corrosive compound.

19. A process for converting methane into methanol, the process comprising:
(i) contacting methane, water, and a supported chromium catalyst comprising chromium in a hexavalent oxidation state with a light beam at a wavelength in the UV-visible spectrum in an oxidizing atmosphere in a single reactor to form a reaction product comprising methanol, wherein:
a molar ratio of water to methane is from 1:2 to 2:1; and
a molar ratio of oxygen (O 2 ) to methane is from 0.1:1 to 1:1;
(ii) discharging a reactor effluent containing the reaction product from the single reactor; and
(iii) separating methanol from the reaction product.

20. The process of claim 19 , wherein:
the supported chromium catalyst comprises a chromium/silica catalyst; and
the single reactor is a fluidized bed reactor.

21. The process of claim 19 , wherein:
a molar ratio of methane to chromium of the supported chromium catalyst is at least 10:1; and
a molar ratio of water to chromium of the supported chromium catalyst is at least 5:1.

22. The process of claim 19 , further comprising a step of condensing to separate the reaction product from the reactor effluent, and wherein separating methanol from the reaction product comprises distillation.

23. The process of claim 19 , further comprising a step of recycling unreacted methane and oxygen from the reactor effluent to the reactor.

24. The process of claim 19 , further comprising a step of calcining the supported chromium catalyst after step (i) to regenerate at least a portion of the supported chromium catalyst comprising chromium in a hexavalent oxidation state.

25. The process of claim 19 , wherein the single reactor has one or more immersion lamps as a source of the light beam attached to a top, attached to a bottom, attached to a wall, or positioned in a wall of the single reactor, or any combination thereof.

26. The process of claim 19 , wherein the single reactor has one or more internal light sources of the light beam, the internal light sources entering through one or more ports positioned at a wall of the single reactor.

27. The process of claim 19 , wherein water is added in step (i) via steam injection into the single reactor.

28. The process of claim 19 , wherein the reactor effluent comprises methanol, unreacted methane, and a reaction by-product comprising formic acid.

Assignees

• Chevron Phillips Chemical Co Lp

Inventors

• Sutherland Jamie N
• Hillier James
• Hendrickson Gregory G
• Mcdaniel Max P

Classifications

• B01J19/123

  Ultraviolet light · CPC title

• B01J8/20

  with liquid as a fluidising medium · CPC title

• B01D53/00

  Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols, (recovery of volatile solvents by condensation B01D5/00; sublimation B01D7/00; cold traps, cold baffles B01D8/00; working-up undefined gaseous mixtures obtained by cracking hydrocarbon oils C10G70/00; cleaning coal gas C10K; working-up of natural gas, or synthetic natural gas, C10L3/10; separation of difficult-to-condense gases or air by liquefaction F25J; for investigating materials G01N30/00) · CPC title

• B01D3/14

  Fractional distillation {or use of a fractionation or rectification column} · CPC title

• C07C29/09

  by hydrolysis · CPC title