Hello all,

We're doing a normal sulfuric esterification on 15% FFA jatropha oil. For some reason, we seem to be getting a weird layer between the triglycerides and the methanol/catalyst/water/biodiesel layer. The layer in between seems to be yellow and somewhat solid or gelly like a soap, but I don't think soap can be made in this process. Anyone have any ideas on what other by-products could be made from esterification? I can post pictures as well if anyone is curious. Thank you!

~Ryan J.

what is the temperature of your mix?
you might be seeing oil gelling in addition to the normal settling.

just a guess

-dkenny

dkenny,

Our reaction for esterification is at 60 C. What do you mean oil gelling? I'm guessing some side reaction due to presence of water?

Thanks~!

~Ryan J.

As it is Jatropha I assume it is virgin oil and has not been used for any other purpose, if it is then 15% is a bit high for virgin Jatropha. This suggests mistreatment either in processing or storage. Have you checked the phosphorus content on the feed oil.

What process has the oil gone through from extraction to esterification? Was it high temperature pressed, cold pressed or solvent extracted, was the oil degummed or are you trying to Esterify the crude oil straight from extraction? Was the extracted oil dried or not?

Also you seem to think that there is a distinct Triglyceride layer and then a separate layer that contains the water, methanol, catalyst and methyl esters. In my (and most others) experiece the Methyl Esters and Triglycerides are all in the upper phase whereas the water/methanol/etc. drops to the bottom. If the Methyl Esters where in the heavy phase it would not be possible to decant off this water/ methanol/ etc. as is done in quite a lot of esterification methods which have worked well.