Im curious if it is possible to do a reaction in a plastic drum, with no other heat than the initial 130F oil that would be poured into the drum.

basically heating the oil 5 gallons at a time, and pouring it into the drum, then adding the methoxide after it is all in the drum, agitating it, and letting it sit.

will this work? or do i need constant heating of the reaction to keep the temp up?

This probably won't be much help as I'm not much of a chemist but my understanding is that it just takes longer and possibly more chemicals to do it cold. I do all my small test batches cold and they come out fine I do heat the processor when I make large batches though.
I would think that the residual heat you would have would be plenty to make it react in a timely manner.
Perhaps some of the experts here can give you better guidance on this.
Regards
Paul

Thanks paul, to date i have only done 2 batches a one liter and a two liter, however they were done in this fashion and came out fine, however if this is able to work on a larger scale, i do not know.

I think past testing has revealed that for each 10 degrees drop, you double the reacion time. I would suggest that you insulate the tank, try this one time with some extended reaction time. Be sure you keep it agitated. Measure the temperature as you progress. If you mix for 2 hours and measure the temp, you will have a better idea how this wil work. Try changing the time to 4 hours mixing or 8 hours mixing? Always run the 27/3 on the oil if you are not sure if the reaction is complete or not.

Also, if you are going to add 5 gallons of heated oil at a time, then I would try adding methoxide at the same time and immediately begin mixing. -- add just enough methoxide for the 5 gallons that you added into the tank.

And a last word of caution. I am hoping that you are mixing/reacting in a sealed vessel. Be sure and have a pressure relief valve. The plastic tank will probably only handle about 5psi(wild guess) before becoming a problem.

Chris

Transesterification is both a time and temperature dependent reaction.

Jon VanGerpen, a recognized academian - biodiesel expert, reported full ASTM conversion biodiesel in an 8 hour reaction at room temperature. His raw material was yellow grease.

steved

Yes.

Per Van Gerpen's paper: ". . . Rendered animal fats and restaurant waste oils with free fatty acid levels of less than 15% are known as yellow grease. If the FFA level exceeds 15%, it may be sold at a discount as brown grease, . . ."

A 15% concentration of FFA is about equal to a titration of 25 to 30.

The paper reported on the results of two stage acid/base reactions. The base reaction followed the acid stage and was performed at room temperature for 8 hours.

This is also the Van gerpen Paper

That concluded that KOH would not make ASTM biodiesel in a single stage if the FFA content was 0.5% which is a KOH titration less than 1.

Your idea is very close to the way I"am doing it.I use a steel drum that I made a cone bottom for. Wraped it r 10 pink foam board. I use 192L of oil in a batch. I only heat 48L, 16L at a time to some where between 140 and 180F. Since I started useing the 27/3 test my results are great. I mix for 1 hour at 15 min intervals. Let set 24 hours, mix one more time let settle then test.