Method of preparing lower alkyl fatty acids esters and in particular biodiesel

• US 6,398,707 B1
• Filed: 05/31/2001
• Issued: 06/04/2002
• Est. Priority Date: 05/31/2001
• Status: Expired due to Term

• Current Assignee: Taiwan Biotech Co. Ltd. (National Express Group Plc /Private Group/)
• Original Assignee: Wen-Teng Wu
• Inventors: Wu, Wen-Teng, Chen, Jech-Wei
• Primary Examiner(s): Carr, Deborah D
• Application Number:
  US09/867,674
• Time in Patent Office: 369 Days
• Field of Search: 584/169, 435/132, 435/134, 435/135
• US Class Current: 554/169
• CPC Class Codes: C11C 3/003 by esterification of fatty acids with alcohols C11C3/02 takes precedence
• CPC Class Codes: C11C 3/10 Ester interchange
• CPC Class Codes: C12N 9/20 Triglyceride splitting, e.g. by means of lipase
• CPC Class Codes: C12P 7/649 Biodiesel, i.e. fatty acid alkyl esters
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

The present invention relates to a technique for enhancing the activity of an immobilized lipase, and a technique for regenerating a deactivated immobilized lipase, in which an alcohol with a carbon atom number not less than three is used to swell and/or clean said immobilized lipase. Said immobilized lipase is particularly useful in a method of preparing biodiesel by transesterification of triglycerides and a lower alcohol.

Claims

1. A method of preparing a C₁-C₃ alkyl ester of a fatty acid by transesterification or esterification of a fatty acid glyceride or a free fatty acid with a C₁-C₃ alcohol, characterized in that a pretreated immobilized lipase is used to catalyze the transesterification or esterification, wherein said pretreated immobilized lipase is prepared by immersing an immobilized lipase in an alcohol having a carbon atom number not less than 3 for a period of time.

2. The method as claimed in claim 1, wherein said alcohol having a carbon atom number not less than 3 has a carbon atom number of 3-8.

3. The method as claimed in claim 2, wherein said alcohol having a carbon atom number not less than 3 has a carbon atom number of 3 or 4.

4. The method as claimed in claim 3, wherein said alcohol having a carbon atom number not less than 3 is 1-propanol, iso-propanol, 1-butanol, 2-butanol, iso-butanol or tert-butanol.

5. The method as claimed in claim 1, wherein said period of time is 0.5-48 hours.

6. The method as claimed in claim 5, wherein said period of time is 0.5-1.5 hours.

7. The method as claimed in claim 1, wherein said pretreated immobilized lipase is prepared by further immersing said immobilized lipase in a vegetable oil for 0.5-48 hours after removing said immobilized lipase from said alcohol having a carbon atom number not less than 3.

8. The method as claimed in claim 1, wherein said immobilized lipase is immobilized on a porous support.

9. The method as claimed in claim 1, wherein said immobilized lipase is from Pseudomanas or Candida.

10. The method as claimed in claim 1, wherein said immobilized lipase is fresh or deactivated.

11. The method as claimed in claim 10, wherein said immobilized lipase is a deactivated immobilized lipase, and said pretreated immobilized lipase is prepared by washing said deactivated immobilized lipase with the alcohol having a carbon atom number not less than 3.

12. The method as claimed in claim 11, wherein said pretreated immobilized lipase is prepared by further immersing said deactivated immobilized lipase in a vegetable oil for 0.5-48 hours after washing said deactivated immobilized lipase with said alcohol having a carbon atom number not less than 3.

13. The method as claimed in claim 1, wherein said C₁-C₃ alkyl ester is prepared by transesterification of said fatty acid glyceride and said C₁-C₃ alcohol.

14. The method as claimed in claim 13, wherein said C₁-C₃ alkyl ester is methyl ester, and said methyl ester is prepared by the transesterification of methanol and an oil or grease comprising a triglyceride.

15. The method as claimed in claim 14, wherein the oil or grease is a vegetable oil.

16. The method as claimed in claim 1, wherein said C₁-C₃ alkyl ester is prepared by transesterification of said fatty acid glyceride and said C₁-C₃ alcohol, and the esterification of said free fatty acid and said C₁-C₃ alcohol.

17. The method as claimed in claim 16, wherein said C₁-C₃ alkyl ester is methyl ester, and said methyl ester is prepared by the transesterification and esterification of methanol and an oil or grease comprising a glyceride and a free fatty acid.

18. The method as claimed in claim 17, wherein said oil or grease is a vegetable oil, an animal grease, a recycled rendered feedstock oils, or a rendered oil or grease generated during the refining of feedstock oils.