Methods of deoxygenation and systems for fuel production

1. A method of deoxygenating oxygenated hydrocarbons, the method comprising:

providing a catalyst comprising a porous substrate and an electrolessly deposited catalytically effective nanoscale metal coating on the substrate;

contacting the catalyst with the oxygenated hydrocarbons and hydrogen so as to accomplish hydrogenation and deoxygenation wherein the deoxygenation is accomplished preferentially by decarbonylation and decarboxylation over hydrodeoxygenation.

2. The method of claim 1 , wherein the ratio of decarbonylation to decarboxylation is about 6:1.

3. The method of claim 1 , wherein the metal comprises palladium.

4. The method of claim 1 , wherein the metal comprises nickel.

5. The method claim 1 , wherein the metal comprises chromium, molybdenum, tungsten, iron, ruthenium, osmium, cobalt, rhodium, iridium, platinum, zinc, silver, gold, copper, or mixtures thereof.

6. The method of claim 1 , wherein the substrate is activated carbon.

7. The method of claim 1 , wherein the porous substrate comprises carbon foam, alumina, silica-alumina, metal foam, silica, zeolites, titania, zirconia, magnesia, chromia, monoliths, or combinations thereof.

8. The method of claim 1 , wherein the porous substrate is granular and comprises activated carbon, alumina, silica-alumina, silica, titania, zirconia, magnesia, chromia, zeolites, or combinations thereof.

9. The method of claim 1 , wherein the catalyst is catalytically active for hydrogenation and preferential deoxygenation of triglycerides by decarbonylation and decarboxylation over hydrodeoxygenation.

10. The method of claim 1 , wherein the catalyst is catalytically active for preferential deoxygenation of alcohols, ethers, aldehydes, ketones, carboxylic acids, esters, phenolics, or mixtures thereof by decarbonylation and decarboxylation over hydrodeoxygenation.

11. The method of claim 1 , further comprising maintaining carbon monoxide partial pressure up to about 0.1 megapascals (15 psi) wherein the metal comprises palladium.

12. The method of claim 1 , wherein deoxygenation of triglycerides is by decarbonylation and decarboxylation over hydrodeoxygenation so that the ratio of odd to even carbon number in the deoxygenated product is about 6:1.

13. The method of claim 1 , wherein the hydrocarbons comprise triglycerides, the carbon substrate is activated carbon, the metal comprises palladium, and the contacting the catalyst with the hydrocarbons and hydrogen so as to preferentially accomplish deoxygenation by decarbonylation and decarboxylation over hydrodeoxygenation is accomplished at temperatures in the range 300° C. to 400° C. and pressures in the range 1.5 megapascals to 15 megapascals.

14. The method of claim 1 , wherein the hydrocarbons comprise triglycerides, the substrate comprises activated carbon, carbon foam, alumina, metal foam, silica-alumina, silica, zeolites, titania, zirconia, magnesia, chromia, monoliths, or combinations thereof, the metal is selected from the group consisting of chromium, molybdenum, tungsten, iron, ruthenium, osmium, cobalt, nickel, rhodium, iridium, palladium, platinum, zinc, gold, silver, copper, or mixtures thereof, and the contacting the catalyst with the hydrocarbons and hydrogen so as to preferentially accomplish deoxygenation by decarbonylation and decarboxylation over hydrodeoxygenation is accomplished at temperatures in the range 300° C. to 400° C. and pressures in the range 1.5 megapascals to 15 megapascals.

15. The method of claim 1 , wherein the catalyst has a metal loading of less than or equal to about 2% with deoxygenation efficiency greater than about 90%.

16. The method of claim 1 , wherein the catalyst has a metal loading of less than or equal to about 1% with deoxygenation efficiency greater than about 90%.

17. The method of claim 1 , wherein the weight hourly space velocity is 0.2 to 2.5.