This weekend I'm going to try doing acid esterification on a 40 gallon batch titrating 9. The way I understand it is you can add the acid directly to the wvo,calualated 182 ml. acid(9-3x.2x152L) for this batch,with 4.8 gallons methanol(60%of the total). 183 ml.of acid doesn't seem like enough. Is there any glycerin formed that should be drained off before I go to the base reaction? I want to start doing the acid process because I have 300 gal.wvo that titrates 15. I found some Rooto which I saw another homebrewer was using but I can't find a percentage of sulfuric acid on the bottle.(I guess it doesn't matter) Is adding the acid to the methanol more effective. As far as I underatand it you can't just pour the KOH or lye in separate from the methanol when doing base reactions so it seems weird that it works with the acid .

no need to drain anything until you have oil that T's around 13 on up. The amount of acid is good, maybe even a few ml's too much based on the current thinking. adding the acid to the methanol or not is personal preference, it appears it doesnt matter if you do it separatly. Good luck.

heatbeater

-I use much less acid with very good results. If you check the acid thread, on the last batch I used a multipier of .10 the thing here, is the wvo has to be very dry. dryness is more imortant in acid esterfication that in the base transeserfication!! Moisture will stop the ae process dead in it's tracks. the conversion of ffa's to esters will be reduced to 5% using Wvo with 5% moisture content!
- try adding the methanol to the wvo first, then mix for 20 - 30 min. after that add the acid. this method works great, and the acid doesn't cause the biodiesel to be as dark. Tom

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no need to drain anything until you have oil that T's around 13 on up. The amount of acid is good, maybe even a few ml's too much based on the current thinking

Will an overdose of acid have any effects ,possibly counteract the base reaction?

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Wvo with 5% moisture content

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Moisture will stop the ae process dead in it's tracks. the conversion of ffa's to esters will be reduced to 5% using Wvo with 5% moisture content!

I'm not to confident when it comes to dewatering wvo. The best I can do is leave the element on and a fan blowing across the top of the reactor tank. Will some of the water separate to the bottom,so I can drain it off? I thought that's how it should work from reading other posts but I"ve never really seen much if any water drain off the bottom after heating ,but maybe I'm not heating it long enough. Just overnight to a day at the most.

heatbeater

-the short answer is no. extra acid seems to give you a faster esterfication process, but this extra acid has to be neutralized in the next base step. If I use .10 as a multipier, it takes about .75gr of KOH to bring the T sample back to neutral. so the more acid you use the more KOH or Naoh you will require. My process takes about 12 - 14 hrs more acid would speed that up for sure. Tom

-to answer your last post,I always let my wvo sit in a heated tank, did a HPT one time to see if this worked , and no bubbles, so in theory wvo was dry. then dkenny starts the acid thread and lots of people trying different ways of ae with varying degrees of success. Through this thread, I have been able to get my final T to average .75. What I did was spend more time drying. bring the wvo into the processor, heat,circulate.and blow air into the tank, it only takes a small amount, this carries the moisture from the tank. Place a cool glass (I often place my eye glass at the opening,) on the escaping air, and if it doesn't fog up, it's good to go.

heatbeater,

how to dry your finished biodiesel?
use the same process to dry the WVO..it works..

Tom's right the drier the better..also think about using about 0.15 instead of 0.2..seems to work better..when in doubt use less acid not more..its easy to add more acid later if needed, but once added you cannot take it back.

-dkenny

if you run into problem PM both Tom and myself..I sure we can help you get started..