I began using a base only process about a year ago. I almost immediately began pre-treating my oil with the previous batch's glycerol with what I thought were good results.

After allowing the BD to settle for a couple of weeks, I draw off the top 2/3 and filter through wood shavings and resin. I pour the rest into a separate container for filtering later. The remaining glycerin and soap go into the next batch.

Over several months I accumulated a lot of extra glycerin/soap/BD glop. I think I have about 40 gallons.

I have been wanting to try acid esterification for quite some time now. Unfortunately I quit making BD back in December when I cut my finger tip on a table saw at my shop. The weather has been unfavorable as well.

Yesterday I decided to get back into gear and started revamping my BD shop with additional settling tanks. I found some Rooto that I bought back in November and took a jar, poured about 150ml of methanol into it, added 10ml of Rooto (Sulfuric Acid), watched it boil for a minute or two, scooped about 900ml of glop into the jar, sealed the jar, shook it up good, set it out into the sun and shook it up again several times while working in my shop.

I took the jar inside overnight and I can see the separation of about 10% brine, 10% glycerol & about 80% darker opaque BD or oil? I am not sure yet what it is as the jar is still sealed.

My initial question is what have I produced?

It seem that the majority of folks here say do the acid stage first and the base last. I have seen some that say the opposite. I have also seen some that suggest maybe using glycerin to neutralize the initial acid stage and proceed with the base stage after draining the glycerin.

My second question is what should I do with the results of esterifying the glop?

My third question is what do you do with the brine? Is there anything you can do other than pouring it down the drain? Any way to make it usable for something other than salty commercial fertilizer?

Eurocab,
If you run a search here on acidulation or Glycerine fractioning, you may find some old posts from Neutral or G.M. or others that I found to be very helpful. Keep adding H2SO4 in 1 ml increments until the precipitate stops. You may have used enough H2SO4 already (I don't have time right now to check the math). At that point you have neutralized the base and the mixture will fraction showing the layers distinctly.

Acid esterfication on bio breaks it back to FFA.
Usually its T-3*.2= ml of acid to add per liter of oil. T is titration.
Being that you are treating bio glop, I would think you need to titrate, then proceed. But Im not sure how the titration works on bio. DK is the man that would know for sure.

Thanks for the responses. I think I will open the jar and do a 27/3 on some of the top layer to see the level of conversion. After searching Acidulating, I think I read that you can throw the top layer back into your oil and process as usual. Acidulating glycerin supposedly produces FFA's, glycerin & brine, so I guess the top layer is FFA's. I see a benefit to this in increasing your yield & less waste. Now the glycerin layer is transparent which might make a better quality soap. But what to do with the brine?

My bad Eurocab,
In my haste I made a mistake. I thought you were trying to fraction crude glycerine to recover the bio, methanol, FFA, and remaining glycerides. Either way though the process would be the same. After fractioning your glop/soap, everything but the salt can be added to a batch that your going to run a acid stage on. If your not going to run an acid stage, It would be a wast to add FFA back to the your oil. The reason for running a glycerine (pre)treatment after an acid stage is to remove the water created during estrification and put a little base in there to pull some FFA's out.
I can't think of any reason to run an acid stage after a base stage though

HTH
-Dave-

I finally got around to doing a 27/3 on the "BD" or whatever it is. Not only did it pass at 50 degrees, I added in steps an additional 3 ml of the oil with zero dropout. I also took a paper towel and soaked it in the oil and it appears to burn like BD. I don't know if there are any other tests I can do without throwing it in the tank. Maybe I will put it in a torpedo heater first.

What are the chances that the top 80% is a combination of bio, FFA, and methanol? Did you wash and dry before your 3/27 (not that it would likely matter, other than removing excess methanol)? Since you acidulated some of the soap creating a salt precipitate, you liberated some FFA. I don't know how FFA effects the 3/27 test (if at all) since 3/27 is usually ran after a base stage which has essentially removed the FFA.
Maybe someone else has this info?
Sounds like it may be usable fuel to me though.
Oh, how about sticking some in the freezer to check it's cold flow properties against a normal batch from the same oil?

quote:

Oh, how about sticking some in the freezer to check it's cold flow properties against a normal batch from the same oil?

Well the concoction sat outside overnight in 22 degree weather and didn't freeze or come close to solidifying. I can't compare it to BD from the same batch as it has been consumed for some time now. This is glop that has accumulated over the last 11 months. Maybe I can titrate it for FFA's.

The interesting thing is, if this is usable, for oil that titrates below the rational level to use acid esterification, it would make a lot more sense to let your soap drop out of the BD, and acidulate the soap to produce more fuel.

A lot less wastestream i.e water, soap & BD down the drain.

I am sure someone else has already thought this out and I am probably wrong, but I can't seem to find out why.

You know Euro,
I've been thinking over the last couple days.
All the batches that I run Acid/base on seem to have a better cold tolerance than single base stages. About 1/4 of the oil I collect is partially hydrogenated oil and I mix the oil together to dry it before processing. I have about 50 gallons of thick (right now) PHO in carboys from one source though. I'm wondering if the acid stage helps the PHO's attain better cold tolerance.
Is any of your oil PHO?
As soon as I'm back up and running this spring this is one of the first tests I want to run (I might need some help remembering though).
Does anyone else out there have any info about this?
-Dave-

Dave,

When I first got started collecting oil, I only collected beautiful oil. Lately though, everyone seems to be using their oil longer and I get a lot of oil titrating around 6 to 8 with some still titrating low. I know that some of it is PHO, by looking at the containers that they came in. I mix them all together too.

I am going to continue experimenting with acidulating glop. I am almost sure it will burn, but not in my truck yet.