Process for the production of fatty acid alkyl esters

• US 6,399,800 B1
• Filed: 09/22/1999
• Issued: 06/04/2002
• Est. Priority Date: 09/22/1999
• Status: Expired due to Fees

• Current Assignee: Agricutlture United States of Americas The As Represented By The Secretary of
• Original Assignee: United States Department Of Agriculture
• Inventors: Bloomer, Scott, Haas, Michael J., Scott, Karen
• Primary Examiner(s): CARR, DEBORAH D
• Application Number:
  US09/400,799
• Time in Patent Office: 986 Days
• Field of Search: 554/175, 554/176, 554/156, 554/157, 554/195
• US Class Current: 554/156
• CPC Class Codes: C07C 51/09 from carboxylic acid esters or lactones
• CPC Class Codes: C07C 53/126 Acids containing more than four carbon atoms
• CPC Class Codes: C07C 67/08 by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds
• CPC Class Codes: C07C 69/52 Esters of acyclic unsaturated carboxylic acids having the esterified carboxyl group bound to an acyclic carbon atom

Abstract

A method for producing fatty acid alkyl esters from a feedstock, involving:

(a) saponifying the feedstock with an alkali to form a saponified feedstock,

(b) removing the water from the saponified feedstock to form a dried saponified feedstock containing no more than about 10% water,

(c) esterifying the dried saponified feedstock with an alcohol in the presence of an inorganic acid catalyst to form fatty acid alkyl esters even with water present at levels up to about 3 wt %, and

(d) recovering the fatty acid alkyl esters.

Claims

1. A method for producing fatty acid alkyl esters from a feedstock, comprising:

(a) saponifying the feedstock with an alkali to form a saponified feedstock,

(b) removing the water from said saponified feedstock to form a dried saponified feedstock wherein said dried saponified feedstock contains no more than about 10% water,

(c) esterifying said dried saponified feedstock with an alcohol and an inorganic acid catalyst to form fatty acid alkyl esters, and

(d) recovering said fatty acid alkyl esters.

2. The method according to claim 1, wherein said feedstock is derived from the group consisting of soy, coconut, corn, cotton, flax, palm, rapeseed/canola, safflower, sunflower, animal fats, waste greases, and mixtures thereof.

3. The method according to claim 1, wherein said feedstock is soy soapstock.

4. The method according to claim 1, wherein said alkali is selected from the group consisting of NaOH, KOH, and mixtures thereof.

5. The method according to claim 1, wherein said dried saponified feedstock contains about 5% water.

6. The method according to claim 1, wherein said dried saponified feedstock contains no more than about 0% water.

7. The method according to claim 1, wherein said alcohol is a straight chain C_1-6 alcohol.

8. The method according to claim 1, wherein said alcohol is selected from the group consisting of methanol, ethanol, and mixtures thereof.

9. The method according to claim 1, wherein said alcohol is methanol.

10. The method according to claim 1, wherein said inorganic acid catalyst is sulfuric acid.

11. The method according to claim 1, wherein said esterifying is conducted at atmospheric pressure.

12. The method according to claim 1, wherein said esterifying is conducted at a temperature of about 25°

-50°

C.

13. The method according to claim 1, wherein said esterifying is conducted at a temperature of about 30°

-40°

C.

14. The method according to claim 1, wherein said esterifying is conducted at a temperature of about 35°

C.

15. The method according to claim 1, wherein said esterifying is conducted at a reaction time of five hours or less.

16. The method according to claim 1, wherein said esterifying is conducted at a reaction time of two hours or less.

17. The method according to claim 1, wherein in (c) the molar ratio of fatty acid:

alcohol is 1;

22-48 and the molar ratio of fatty acid;

inorganic acid catalyst is 1;

2-3.

18. The method according to claim 1, wherein in (c) the molar ratio of fatty acid:

alcohol;

inorganic acid catalyst is 1;

30;

2.5.

19. The method according to claim 1, wherein in (c) about 100% of the fatty acids are esterified.

20. The method according to claim 1, wherein said esterifying is conducted in the presence of up to about 3 wt % water.

22. The method according to claim 1, wherein said feedstock is soapstock.

21. A method for producing fatty acid alkyl esters from a feedstock, consisting essentially of:

(a) saponifying the feedstock with an alkali to form a saponified feedstock,

(b) removing the water from said saponified feedstock to form a dried saponified feedstock wherein said dried saponified feedstock contains no more than about 10% water,

(c) esterifying said dried saponified feedstock with an alcohol and an inorganic acid catalyst to form fatty acid alkyl esters, and

(d) recovering said fatty acid alkyl esters.