After doing a couple of botched AE's I have to re-process after the first base process because the batch didn't convert completely. The methanol used in the Ae process didn't have the full effect like it did when I just did base reactions. This adds extra costs which is the opposite of my goal . Perhaps some of the methanol vapor is leaking out. My processor is a 55 gal. drum with a lid ,but the lid is a little bigger in diameter than the drum so it doesn,t fit tight. . i just convinced myself to try using duck tape to seal the lid better. Are other brewers doing AE having to use a higher percentage of methanol to completely convert their bio?

heatbeater

-this happens if the wvo is wet, the methanol takes up the water and the purity isn't there for the base reaction. You could be losing methanol to evaporation as well, seal up the lid, but make sure you use a vent tube so the processor doesn't build up pressure. a 1/2" pipe about 2.5 ft long will work. any methanol vapours entering the pipe will condense and fall back into the reaction. Tom

An open reactor will never give consistant results, I hope you use it outside on windy days.

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-this happens if the wvo is wet, the methanol takes up the water and the purity isn't there for the base reaction

So if everything is right I should only use 20% methanol (split 10/10% acid/base)to get the job done?

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Posted 01 August 2009 11:02 AM Hide Post
An open reactor will never give consistant results, I hope you use it outside on windy days

Its actually in a small shed thats open on two sides and I keep a lid on it. Sounds like I should seal the lid with duck tape and run a vent pipe to the outside until the reaction is done ,but have to come up with a way to pull samples to know when the reaction is done. This drum that i use for a reactor had the top cut out of it. The lid comes from another drum . Something I didn't know until it was to late is that the diameter between the 2 drums have about an inch difference. Sealed drums and removeable lid drums are not the same diameter, at least from what I've seen. It would be nice to find a lid that fit snug.

heatbeater

-small modification will fix the sampling situation, put a T in the pipe exiting the pump, and pit in a boiler tap, then you can samole at any time.
-in answer to your question, YES That's all that is required.Since the acid thread started, I have increased my toal methanol to 22%, 10% for acid, the remainder split up in the base/base 90/10 process I swithed to 90/10, because often I can pass 3/27 after the first base stage, then I save a step. Tom

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small modification will fix the sampling situation, put a T in the pipe exiting the pump, and pit in a boiler tap, then you can samole at any time.

Not quite sure what you mean by a boiler tap, some kind of valve I'm guessing. Looks like there's 2 things I need to work on 1) sealing up the reactor to elinimate methanol from vaporizing 2) better dewatering. How much water is left in the wvo after my dewatering process is a good question. I've done HPT and they seemed good. It would be nice if I coukld afford one of those $200 water test that Graydon sells. My HPT will have a little steam forming on the bottom side of the lid ,but not enough to drop back into the wvo,that's the best it gets. Been thinking about using Quik n' dri but for some reason I"m skeptical. Maybe it's the current economy.

You could be needing to use more methanol due to the water created from the esterification. This is more problematic when using higher titration oil since more water is created. If the water that's created doesn't settle to the bottom where it can be drained then it has to be considered in the base stage. Just because it doesn't settle doesn't mean it's not there. For every mole of FFA that is esterified there is one mole of water created.

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You could be needing to use more methanol due to the water created from the esterification. This is more problematic when using higher titration oil since more water is created

I never heard of more water being created during the process if the wvo was orginally dewatered. Unless you're saying that any remnents of water in the wvo will standout? I've only been home brewing for less than a year so I don't know.

When transesterfying WVO, for every 1% of FFA content there there will be 0.064% of water produced.
To calculate FFA % multiply the NaOH titration by 0.766.

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When transesterfying WVO, for every 1% of FFA content there there will be 0.064% of water produced.
To calculate FFA % multiply the NaOH titration by 0.766

This current batch titrates 10.5 KOH

The water produced when FFA is esterfied is 6.4% of the weight of the FFA consumed. To convert a KOH titration to FFA % multiply by 0.546.

a titration of 10.5 x .546=5.74x.64=.37(that figure is percent of water?) In 45 gallons of wvo I get a figure of 16.65. It can't be 16.65 gallons of water produced?

Your Oil contains 5.74% FFA by weight
1 Litre of oil weighs about 900g.
5.74% of 900g= 51.66g of FFA in each liter.
6.4% of 51.66g= 3.31g of water produced from each liter of oil
3.31g of water= 3.31ml of water per litre of oil
45 Gallons oil= 170.3 litrers of oil
3.31ml of water X 170.3= 563.7 ml/ 0.15 gallons of water produced for the entire batch.

Kevin,Thanks for the explanation.