[beheada]

I am confused on what the actual by-product of biodiesel is. On some websites I have found they call it glyercine and others glycerol. I've heard of some people using the byproduct to make soap, but I was wondering (if it is in fact glycerine) if it was of high enough purity to use in creating formic acid from byproduct and oxalic acid!? Are there too many impurities for this?

Does anyone have a good website on purifying the byproduct (glycerine/glycerol) to straight glycerine? Waste not, want not.

[Alberto_Kravina]

Biodisel is the methyl esther of certain fatty acids (with about 16 - 20 Carbon atoms), which are contained in i.e. vegetable fats as triglycerides (3 fatty acids estherified with Glycerol (which is EXACTLY the same as Glycerine), see also http://en.wikipedia.org/wiki/Glycerol ). I don't know if it can be use to make soap, but glycerine has many other applications.

However - I don't know if you can use it to produce oxalic acid and formic acid, actually I've never heard about  this synthesis 

[beheada]

On the Wikipedia page provided for Formic Acid at the end of production techniques it says that Formic Acid may be produced "by heating oxalic acid in anhydrous glycerol and extraction by steam distillation". This is the reaction I was interested in.

Wouldn't this require prep work on the glycerol produced, since there are probably contaminants and water. Although it could be dried... my ponderance was whether any other impurities would stop the reaction from taking place? Not to mention the glycerine, even if pure, is hygroscopic and absorbs moisture from the air (which I guess means you need to do it under a nitrogen atmosphere?).

In making biodiesel, I've heard of alot of people making soap with their glycerine. Yet, upon research I found that it's actually just an additive in the soap making process. Since I have no interest in... soap, I was just trying to see if I could possibly use it for other things. Maybe sell it to people that use it in their soap production process?

[billnotgatez]

In general one would think that if you are producing an energy source that the energy cost to create that source is not greater than the energy derived. In other words you do not want to have a net negative energy gain. At least in the economic sense you do not want bio-diesel to cost more money to produce than regular diesel. The cost of creating a product includes the disposal of byproducts. If you had to use the energy gain you got by creating the bio-diesel to process the byproducts then the process would not be profitable. My impression is that the production of soap using glycerin is still profitable. I am not sure the demand for Formic Acid is the same as soap.

By the way there are several posts to this forum involving bio-diesel that have interesting links.

Beheada – have you created some bio-diesel?

[beheada]

Yes, I've been through the entire process of creating biodiesel from OTC oils and from oils I received from restaraunts. The restaraunt oil was profitable because the starting source was FREE, but someplaces have started to charge to give away their oil, and you have to filter/titrate the stuff before you use it. All things aside, I've seen all the links and I've been to biodiesel websites, and I know that glycerol can be used with the creation of soap (to make the process of making biodiesel even MORE profitable, i.e. free oil = cheap biodiesel at the cost of reagents + glycerol for soap). But the point I was getting at, is not whether one can use glycerol for soap or anything about the biodiesel process...

The point was whether or not the glycerol byproduct from the production of biodiesel is pure enough to use with oxalic acid. I ask because I haven't purchased any oxalic acid and I don't want to waste money on reagents I can't use, if in fact the reaction won't work. I'm beginning to think it won't work, due to the fact that the synthesis involved uses ANHYDROUS glycerol and its a hygroscopic compound. First off, I'm not sure how to make a hygroscopic compound which draws moisture from the air, anhydrous unless reacting it under a nitrogen atmosphere? Secondly, I'm not really sure how I would go about purifying the glycerol of other impurities (any other byproduct of the biodiesel reaction).

Hence...the question I pose:

How would I purify the glycerol byproduct of biodiesel in order for it to be suitable for another anhydrous reaction?

rayfe

[billnotgatez]

As I said before there are several post on this in the forum. One of which was a proposed experiment by me to determine the net energy production. As happens many times that experiment has fallen to the bottom of my to do list (sinner that I am). In any case I pondered your question.
You are at least one step ahead of me, since you actually have done this process. If I recollect correctly the glycerin settles to the bottom. I do not know how much moisture could be within the glycerin but it seems to me that it separates out fairly well. The only question we have is how dry is it. Also, I am not familiar with the formic acid reaction you are trying to do, so I am not sure how much moisture would totally disrupt your proposed reaction.

[Yggdrasil]

I would assume your glycerol would be contaminated with water.  Glycerol forms hydrogen bonds pretty readily, so it would likely adsorb a lot of the water in the reaction mixture when you are hydrolyzing your oils.  If you wanted to use your glycerol for a reaction which must proceed under anhydrous conditions, you would have to find some way to purify it, or at least remove the water from it (unfortunately, I'm not familiar with any procedures to purify glycerol).

[beheada]

The Experiment I've come up with:

Since the information doesn't seem to be readily available, but I have a strong hunch toward the main impurity of my glycerol simply being water, I've come up with a way to "hopefully" make the glycerol anhydrous and pure enough to react with oxalic acid to produce formic acid or allyl alcohol (depends on temperature, I believe). Regardless... here follows my train of thought:

Glycerol is viscous and thick, so attempting to dump in a drying agent would be problematic during the filtration process. However, the boiling point of glycerol is 290C as opposed to water... so my two methods for water removal will be...

1) Boil the water from the glycerol at a constant temperature above 100C until the boiling stops...

2) Gather drying agent (calcium chloride/ MgSO4) and place within an empty teabag (from the co-op natural food store) and drop in necessary amount of drying agent. Drying agent should hopefully absorb the water in the aqueous solution, and then simply remove the tea bag. This could be done in a vaccuum dessicator if needed, but I don't think the hygroscopic properties of glycerol are enough to warrant such.

After the proposed drying ideas, attempt reaction with the oxalic acid and see if the reaction proceeds?

[billnotgatez]

I like the idea of an experiment.

Are you going to do it on the beaker / test tube sizes first and then upsize it.

If you do the heating method, are you going to use the bio-diesel to provide the heat?

I wonder what effect the sodium hydroxide left behind from the water will have with the drying process or the formic acid process

[beheada]

I'll be doing it at the beaker level first. Under 1L because that's as big a sep funnel provided. I'll post the results. Heating will be with a hotplate/stirrer combo... but it would be nice to use the biodiesel for heating. I'll report experimental proceedings as soon as they're done.

[beheada]

I'm working on the experiment making formic acid from the glycerine byproduct of biodiesel. While that's in the works (since I've had finals and been busy) I thought if anyone was interested in this, they should check out this site on glycerine from a biodiesel page.

http://journeytoforever.org/biodiesel_glycerin.html

It goes into alot of the information I was originally looking for when I made this post.

[billnotgatez]

That site plus several others are on previous posts about bio-diesel.

Someone said the site you just posted has inaccuracies and asked me not to recommend it
On the other hand it has a collection of data hard to find elsewhere.
 

[constant thinker]

Ok, just for reference here are some of the past biodiesel topics.

Converting Byproduct from Biodisessel Process into Fertiliser
http://www.chemicalforums.com/index.php?topic=9367.0
Bio-diesel Experiment Proposition
http://www.chemicalforums.com/index.php?topic=7087.0
Biodiesel
http://www.chemicalforums.com/index.php?topic=4064.0
Bio-diesel
http://www.chemicalforums.com/index.php?topic=5177.0

I think I've got them all, so for anyone else who may be thinking, "hmm I want more information." You now know where to get it.

[feeceoil]

Thanks for the information, this site is very informative..

constant thinker, Thanks for the links..

Feece Oil Fuel