Chromium-catalyzed production of alcohols from hydrocarbons

1. A process for converting a hydrocarbon reactant into an alcohol compound and/or a carbonyl compound, the process comprising:

(i) irradiating the hydrocarbon reactant and a supported chromium catalyst comprising chromium in a hexavalent oxidation state with a light beam at a wavelength in the UV-visible spectrum to reduce at least a portion of the supported chromium catalyst to form a reduced chromium catalyst;

(ii) hydrolyzing the reduced chromium catalyst to form a reaction product comprising the alcohol compound and/or the carbonyl compound; and

(iii) separating at least a portion of the hydrocarbon reactant from the reaction product, wherein the at least a portion of the hydrocarbon reactant is recycled and irradiated with the supported chromium catalyst again.

2. The process of claim 1 , wherein the hydrocarbon reactant comprises a C 1 to C 36 linear, branched, or cyclic alkane compound.

3. The process of claim 1 , wherein the hydrocarbon reactant comprises methane, ethane, propane, butane, or a combination thereof.

4. The process of claim 1 , wherein the supported chromium catalyst contains from about 0.01 to about 50 wt. % of chromium, based on the weight of the supported chromium catalyst.

5. The process of claim 1 , wherein the reduced chromium catalyst contains chromium having an average valence of less than or equal to about 5.25.

6. The process of claim 1 , wherein the wavelength comprises a single wavelength or a range of wavelengths in a range from about 200 nm to about 750 nm.

7. The process of claim 1 , wherein the irradiating step is conducted at a temperature from about 0° C. to about 100° C.

8. The process of claim 1 , wherein the process comprises:

contacting the hydrocarbon reactant with a fluidized bed of the supported chromium catalyst, and irradiating while contacting; or

contacting the hydrocarbon reactant with a fixed bed of the supported chromium catalyst, and irradiating while contacting.

9. The process of claim 1 , wherein:

hydrolyzing is conducted at a temperature from about 0° C. to about 100° C.; and

hydrolyzing comprises contacting the reduced chromium catalyst with a hydrolysis agent comprising water, steam, an alcohol agent, an acid agent, an alkaline agent, or any combination thereof.

10. The process of claim 1 , wherein a conversion of the hydrocarbon reactant is at least about 10 wt. %.

11. The process of claim 1 , wherein a molar yield of the alcohol compound and/or the carbonyl compound is from about 0.01 to about 2 moles of the alcohol compound and/or the carbonyl compound per mole of chromium (VI) in the supported chromium catalyst.

12. The process of claim 1 , further comprising a step of separating at least a portion of the alcohol compound and/or the carbonyl compound from the reaction product after step (ii).

13. A process for converting a C 1 -C 6 alkane compound into a C 1 -C 6 alcohol compound, the process comprising:

(a) irradiating the C 1 -C 6 alkane compound and a supported chromium catalyst comprising chromium in a hexavalent oxidation state with a light beam at a wavelength in the UV-visible spectrum to reduce at least a portion of the supported chromium catalyst to form a reduced chromium catalyst;

(b) hydrolyzing the reduced chromium catalyst to form a reaction product comprising the C 1 -C 6 alcohol compound; and

(c) separating at least a portion of the C 1 -C 6 alkane compound from the reaction product, wherein the at least a portion of the C 1 -C 6 alkane compound is recycled and irradiated with the supported chromium catalyst again.

14. The process of claim 13 , wherein:

the supported chromium catalyst contains from about 0.01 to about 50 wt. % of chromium, based on the weight of the supported chromium catalyst; and

the reduced chromium catalyst contains chromium having an average valence of less than or equal to about 5.25.

15. The process of claim 13 , wherein the alkane compound comprises methane and the alcohol compound comprises methanol.

16. The process of claim 15 , wherein the reaction product further comprises formic acid.

17. A process for converting a hydrocarbon reactant into an alcohol compound and/or a carbonyl compound, the process comprising:

(i) irradiating the hydrocarbon reactant and a supported chromium catalyst comprising chromium in a hexavalent oxidation state with a light beam at a wavelength in the UV-visible spectrum to reduce at least a portion of the supported chromium catalyst to form a reduced chromium catalyst;

(ii) hydrolyzing the reduced chromium catalyst to form a reaction product comprising the alcohol compound and/or the carbonyl compound;

(iii) separating at least a portion of the reduced chromium catalyst from the reaction product; and

(iv) calcining the at least a portion of the reduced chromium catalyst to regenerate the supported chromium catalyst.

18. The process of claim 17 , wherein:

the supported chromium catalyst contains from about 0.01 to about 50 wt. % of chromium, based on the weight of the supported chromium catalyst; and

the hydrocarbon reactant comprises methane, ethane, propane, butane, or a combination thereof.

19. The process of claim 17 , wherein a molar yield of the alcohol compound and/or the carbonyl compound is from about 0.05 to about 1.8 moles of the alcohol compound and/or the carbonyl compound per mole of chromium (VI) in the supported chromium catalyst.

20. The process of claim 17 , wherein a conversion of the hydrocarbon reactant is at least about 10 wt. %.

21. The process of claim 17 , wherein the process comprises:

contacting the hydrocarbon reactant with a fluidized bed of the supported chromium catalyst, and irradiating while contacting; or

contacting the hydrocarbon reactant with a fixed bed of the supported chromium catalyst, and irradiating while contacting.