Method for esterification of free fatty acids in triglycerides
View Patent ↗A method for esterification of free fatty acids in triglycerides, with C 1 -C 8 aliphatic alcohols. The method uses an acidic ion exchange resin as a catalyst. The catalyst is contacted with a reaction mixture containing a triglyceride having at least 1% free fatty acids and a C 1 -C 8 aliphatic alcohol under conditions suitable for esterification.
1. A method for esterification of free fatty acids in triglycerides with C 1 -C 4 aliphatic alcohols; said method comprising steps of:
(a) providing a catalyst comprising a gel-type acidic ion exchange resin having 0.5% to 2.5% crosslinker and sulfonic acid functionality and which comprises polymerized units of styrene and a crosslinker; and
(b) contacting said catalyst with a reaction mixture comprising: (i) a triglyceride having at least 1% free fatty acids; and (ii) a C 1 -C 4 aliphatic alcohol in a temperature range from 40° C. to 110° C.
2. The method of claim 1 in which the C 1 -C 4 aliphatic alcohol is selected from the group consisting of methanol and ethanol and the alcohol is present in an amount of at least 2 equivalents based on free fatty acid.
3. The method of claim 2 in which the resin has 1% to 2.5% crosslinker.
4. The method of claim 3 in which the triglyceride has 1% to 80% free fatty acids.
5. The method of claim 4 in which the resin has an average particle size from 100 μm to 2000 μm.
6. The method of claim 5 in which the reaction mixture is heated in a batch reactor in a temperature range from 40° C. to 90° C. for at least 0.5 hours.
7. The method of claim 5 in which the reaction mixture is in contact with catalyst in a continuous reactor in a temperature range from 40° C. to 90° C. for at least 15 minutes.
8. The method of claim 3 in which the triglyceride has 1% to 20% free fatty acids.
9. The method of claim 8 in which the aliphatic alcohol is methanol.
10. The method of claim 9 in which the reaction mixture is heated in a batch reactor in a temperature range from 40° C. to 90° C. for at least 0.5 hours.
11. The method of claim 9 in which the reaction mixture is heated in a continuous reactor in a temperature range from 40° C. to 90° C. and the reaction mixture is in contact with the catalyst for at least 0.5 hours.
12. The method of claim 3 in which the triglyceride has from 2% to 10% free fatty acids.
13. The method of claim 12 in which the aliphatic alcohol is methanol.