I've been looking for a way to deal with problem WVO without the hassle of using sulfuric acid. I found some valuable info on the SVO side of this forum and some great work done by Tim c cook. It has to do with neutralization of FFAs using baking soda and you can read about it here

I'm wondering why there hasn't been more discussion on the biodiesel side of this forum on this subject.

I don't know about the baking soda thing. I saw that and wondered too.

I'm going to handle the FFA in waste oil with Magnesol XL, which is designed for exactly this. I know there is alot writen here about waterless washing your BD with it and the final filtering nightmare that can cause, but it can (hopefully) drop FFA in WVO alot. I figured if it brings my titration down 3.25ml (from 7-9ml KOH, typically, to 4-6ml), I will be breaking even on cost verse the extra catalyst necessary. My first few small bags of Magnesol are in the mail. I'll be reporting back how it goes.

Definitely interested in knowing how that magnesol works for you. Please, keep us posted.

Let us know how it works. From what I've read from the various companies that supply similar filtration systems to restaurants, they remove the water and the particulates from the oil thereby slowing down the development of FFA.

Damn...

I'm getting into the wrong business..

I need to figue out how to make magnesol...

I know that a lot of people are concerned about Magnasol and other fryer powders because of very fine particles that cannot be removed by conventional filtering. Also, the clear water pumps we tend to use chop up the fryer powders even more.

The baking soda causes a reaction with CO2 being the byproduct and FFA reduction being the end result. Cheap and no particulate left in the bio.

I am currently experimenting with some high FFA oil reacting with the baking soda. I'll keep you informed. I assume it is like putting baking soda on your car battery terminals or pouring a carbonated soda on them. It destroys the acid.

I think the link I posted above doesn't work so I'll get a working one up. It was a late night when I posted this.

The link works Woo Woo.

Results-I dumped 5 lbs of Baking Soda into a 55 gallon drum of WVO that titrated at 30 g/l using KOH. I didn't dissolve the BS, just dumped it in and stirred. It bubbled for a week and I just did a titration. 23 g/l. Not bad for an investment of $3.

On my next trip to town I'll pick up 10 lbs and try that. If I can get the titration down another 10 g/l I'll feel comfortable about making biodiesel out of it.

Stay tuned.

Can anyone explain the specific chemical reactions? Is co2 the only byproduct?

Is there anything else that may interfere with your biodiesel reaction?

quote:

Originally posted by Curt B:
Can anyone explain the specific chemical reactions? Is co2 the only byproduct?

Is there anything else that may interfere with your biodiesel reaction?

I would like to know the answer to this too.
I pick up some 8.5 to 9 WVO just because it's right next door to my .75 Canola stop and it's nice to have a little extra to play with but it sure eats the KOH. If there was a cheap easy way to drop the FFA's that would be cool.

acid and base usually form a salt of some kind when they react together.

quote:

Originally posted by Curt B:
Can anyone explain the specific chemical reactions? Is co2 the only byproduct?

Is there anything else that may interfere with your biodiesel reaction?

From a chemist perspective:
Baking soda is NaHCO3(sodium bicarbonate)
Acid + NaHCO3 -> NaSalt + H20 + CO2
ie HCL + NaHCO3 -> NaCL(table salt) + H2O + CO2

Check the SVO discussions this subject has been discussed in depth.
I've read where flour has been added to remove water too. Now that's got to be a mess!

Awesome. So will all Free fatty acids and baking soda just break down into a salt, water and co2?

quote:

Originally posted by Curt B:
Awesome. So will all Free fatty acids and baking soda just break down into a salt, water and co2?

No, I wouldn't say ALL FFAs and BSoda break down. It is really all dependent upon the amount of FFA and the amount of BSoda present. There will always be left over Bsoda or FFA when using "bucket" chemistry. If you can hookup with a good Organic chemist (not me)they could do some number crunching with the FFA's and amount of Bsoda to use to give you a more "complete" reaction.
From what I've read on the SVO board, a titration is done, Bsoda added, another titration, more Bsoda, etc, until FFA's are acceptable. That sounds like your best bet.

quote:

Originally posted by uniquewater:

quote:

Originally posted by Curt B:
Awesome. So will all Free fatty acids and baking soda just break down into a salt, water and co2?

No, I wouldn't say ALL FFAs and BSoda break down. It is really all dependent upon the amount of FFA and the amount of BSoda present. There will always be left over Bsoda or FFA when using "bucket" chemistry. If you can hookup with a good Organic chemist (not me)they could do some number crunching with the FFA's and amount of Bsoda to use to give you a more "complete" reaction.
From what I've read on the SVO board, a titration is done, Bsoda added, another titration, more Bsoda, etc, until FFA's are acceptable. That sounds like your best bet.

There is also a post which shows how to remove the ffa using naoh...

Remove FFA using NaOH

Which procedure will be better?

I've started a new post similar to this...
http://biodiesel.infopop.cc/eve/forums/a/tpc/f/719605551/m/8631059151

quote:

Originally posted by bio-LOGIC:
Results-I dumped 5 lbs of Baking Soda into a 55 gallon drum of WVO that titrated at 30 g/l using KOH. I didn't dissolve the BS, just dumped it in and stirred. It bubbled for a week and I just did a titration. 23 g/l. Not bad for an investment of $3.

On my next trip to town I'll pick up 10 lbs and try that. If I can get the titration down another 10 g/l I'll feel comfortable about making biodiesel out of it.

Stay tuned.

Anything to report yet?

My take on the chemistry:

I think the baking soda is making soap (sodium salt of a fatty acid). The same can be done with sodium or potassium hydroxide as in the link a couple posts above. In the vegetable oil industry this is referred to as alkaline refining.

I would think that the soap ought to be removed (centrifuged or washed) before running the transesterification reaction, but that’s a lot of effort.

Acid catalysis turns FFA into fuel. Alkaline refining turns it into soap. They both involve a lot of effort, but each has advantages and disadvantages based on your process and equipment.

Jack

It's nice to see this thread go back into the baking soda direction and away from Magnasol.

quote:

Acid catalysis turns FFA into fuel. Alkaline refining turns it into soap. They both involve a lot of effort, but each has advantages and disadvantages based on your process and equipment.

My preferecnce is to work with a less dangerous substance than sulfuric acid. However turning FFAs into fuel has a lot of attraction. Fuel is a lot more valuable than soap in this economy.

I just checked the 55 gallon barrel of problem oil I'd added baking soda to, and there is solid soap forming on the surface. I've learned from this topic that soap cannot exist in solution without water, methanol (or other alcohols). I'm sure there are other solutions where soap can be present but in this case the soap is coming to the surface presenting it's self for removal from the equation.

I'll titrate after the reaction stops.