SHORT CHAIN ALCOHOL PRODUCTION FROM GLYCERIN

1 . A method for converting glycerol to monohydric alcohol, the method comprising:

contacting a gaseous material comprising glycerol with a heterogeneous dehydration catalyst at a temperature and a pressure sufficient to convert at least a portion of the glycerol to one or more compounds having at least one of a carbon-carbon double bond and a carbon-oxygen double bond, whereby a dehydrated glycerol material is obtained;

adding hydrogen gas to the dehydrated glycerol material;

contacting the mixture of hydrogen gas and dehydrated glycerol material with a hydrogenation catalyst at a temperature and a pressure sufficient to convert at least a portion of the compounds having at least one of a carbon-carbon double bond and a carbon-oxygen double bond to one or more monohydric alcohols, whereby a hydrogenated mixture is obtained; and

separating a monohydric alcohol-rich portion from the hydrogenated mixture.

2 . The method of claim 1 , wherein the monohydric alcohol-rich portion comprises at least 75 wt. % monohydric alcohols

3 . The method of claim 1 , wherein the monohydric alcohol-rich portion comprises at least 70 wt. % 1-propanol.

4 . The method of claim 1 , wherein the step of contacting a gaseous material is conducted at a pressure of from about 0.5 bar (absolute) to about 10 bar (absolute), and at a temperature of from about 260° C. to about 340° C.

5 . The method of claim 1 , wherein the step of contacting a gaseous material is conducted at a pressure of from about 4 bar (absolute) to about 7 bar (absolute), and at a temperature of from about 280° C. to about 320° C.

6 . The method of claim 1 , wherein the step of contacting the mixture of hydrogen gas and dehydrated glycerol material is conducted at a pressure of from about 0.5 bar (absolute) to about 10 bar (absolute), and at a temperature of from about 150° C. to about 400° C.

7 . The method of claim 1 , wherein the step of contacting the mixture of hydrogen gas and dehydrated glycerol material is conducted at a pressure of from about 4 bar (absolute) to about 7 bar (absolute), and at a temperature of from about 250° C. to about 350° C.

8 . The method of claim 1 , wherein the dehydration catalyst comprises oxides of tungsten and zirconium.

9 . The method of claim 1 , wherein the hydrogenation catalyst comprises a platinum group metal.

10 . The method of claim 1 , wherein an amount of hydrogen in the mixture of hydrogen gas and dehydrated glycerol material is from about 0.9 to about 10 times the amount of carbon-carbon double bonds and carbon-oxygen double bonds present in the mixture on a molar basis.

11 . The method of claim 1 , further comprising steps of:

separating at least a portion of at least one compound selected from the group glycerol, propylene glycol, ethylene glycol, hydroxyacetone, propionaldehyde, acrolein, acetone, acetaldehyde, and formaldehyde from the dehydrated glycerol material; and

contacting the separated portion with the heterogeneous dehydration catalyst.

12 . The method of claim 1 , wherein glycerol is present at a mole fraction of from about 10% to about 30%, and water is present at a mole fraction of from about 70% to about 90% in the gaseous material.

13 . The method of claim 1 , wherein the gaseous material further comprises at least one monohydric alcohol.

14 . The method of claim 13 , wherein the monohydric alcohol is selected from the group consisting of methanol, ethanol, and propanol.

15 . The method of claim 13 , wherein monohydric alcohols make up from about 0.1 wt. % to about 30 wt. % of the gaseous material.

16 . The method of claim 13 , wherein monohydric alcohols make up from about 0.1 wt. % to about 15 wt. % of the gaseous material.

17 . The method of claim 13 , wherein monohydric alcohols make up from about 0.1 wt. % to about 5 wt. % of the gaseous material.

18 . The method of claim 13 , wherein monohydric alcohols make up from about 0.1 wt. % to about 2 wt. % of the gaseous material.

19 . The method of claim 13 , wherein monohydric alcohols make up less than about 0.5 wt. % of the gaseous material.

20 . The method of claim 1 , wherein the gaseous material further comprises at least one fatty acid methyl ester.

21 . The method of claim 20 , wherein fatty acid methyl esters make up from about 0.1 wt. % to about 2 wt. % of the gaseous material.

22 . The method of claim 1 , wherein the gaseous material further comprises at least one fatty acid ethyl ester.

23 . The method of claim 22 , wherein fatty acid ethyl esters make up from about 0.1 wt. % to about 2 wt. % of the gaseous material.

24 . The method of claim 1 , wherein the gaseous material further comprises at least one fatty acid propyl ester.

25 . The method of claim 24 , wherein fatty acid propyl esters make up from about 0.1 wt. % to about 2 wt. % of the gaseous material.

26 . The method of claim 1 , wherein the gaseous material contains from about 0.1 wt. % to about 20 wt. % hydrogen.

27 . The method of claim 1 , wherein the gaseous material further comprises hydrogen at about 0.2% to about 2% (molar).

28 . A method for converting glycerol to monohydric alcohol, the method comprising:

contacting a gaseous material comprising glycerol with a heterogeneous dehydration catalyst at a temperature and a pressure sufficient to yield a first reacted material comprising carbon monoxide, water, and one or more carbonyl-containing molecules;

contacting the first reacted material with a water-gas shift reaction catalyst at a temperature and a pressure sufficient to yield a second reacted material comprising hydrogen; and

contacting the second reacted material with a heterogeneous hydrogenation catalyst at a temperature and a pressure sufficient to convert at least a portion of the carbonyl-containing molecules to one or more monohydric alcohols in a hydrogenated material.

29 . The method of claim 28 , wherein the step of contacting a gaseous mixture occurs at a temperature of from about 250° C. to about 380° C., and at a pressure of from about 1 bar (absolute) to about 10 bar (absolute).

30 . The method of claim 28 , wherein the step of contacting a gaseous mixture occurs at a temperature of from about 280° C. to about 320° C., and a pressure of from about 4 bar (absolute) to about 7 bar (absolute).

31 . The method of claim 28 , wherein the heterogeneous dehydration catalyst comprises oxides of tungsten and oxides of zirconium.

32 . The method of claim 28 , wherein the step of contacting the first reacted material is conducted at a temperature of from about 220° C. to about 380° C., and at a pressure of from about 1 bar (absolute) to about 10 bar (absolute).

33 . The method of claim 28 , wherein the step of contacting the first reacted material is conducted at a temperature of from about 270° C. to about 330° C., and at a pressure of from about 4 (absolute) to about 7 bar (absolute).

34 . The method of claim 28 , wherein the contacting with a heterogeneous hydrogenation catalyst occurs at a temperature of about 150° C. to about 400° C. and the pressure of about 0.5 to about 10 bar (absolute).

35 . The method of claim 28 , wherein the step of contacting the second reacted material is conducted at a temperature of from about 250° C. to about 350° C., and at a pressure of from about 4 bar (absolute) to about 7 bar (absolute).

36 . The method of claim 28 , further comprising a step of separating an alcohol-rich material and an alcohol-depleted material from the hydrogenated material, wherein the alcohol-depleted material comprises predominantly carbon dioxide and hydrogen.

37 . The method of claim 36 , wherein the alcohol rich material comprises at least 70 wt. % 1-propanol.

38 . The method of claim 36 , further comprising a steps of:

treating the alcohol-depleted material via pressure-swing absorption to remove at least a portion of the carbon dioxide present, resulting in a carbon dioxide-rich material and a hydrogen-rich material; and

recycling the hydrogen-rich material to the step of contacting a gaseous material.