I work in a cottonseed oil mill. Our refining process (KOH) produces around 10,000 gallons of soap/day. I am looking at the possibility of treating the soap with heat and H3PO4 to turn the soap back into ffa, decanting/vacuuming off the water, then esterify into biodiesel.
I know this is a homebrew site, and I may be barking up the wrong tree, I am just wondering if this esterification can be done without getting too high tech.

I think you can do it from soapstock using the process you describe. The Iowa State University-developed acid-base process will do it according to them. The process here is written up at this thread:
http://biodiesel.infopop.cc/eve/forums?a=tpc&s=447609751&f=629605551&m=933108762

and you will need to deal with the complicated issues around the large amounts of water that will be formed:

http://biodiesel.infopop.cc/eve/forums?a=tpc&s=447609751&f=629605551&m=585600516


Now, I haven't tried it at such high percentages of FFA, nor do I have any experience playing around with the methanol management/water issues. At the ISU biodiesel workshops I think we worked with 80% ffa and definitely with trap fgrease of a 56% ffa, and I'm unfortunately not sure of how water-logged the excess methanol layer was that resulted fromt he first step since we didnt' deal with it.

Mark

Girl Mark:

The ffa oilstock will have to be dewattered with intense vacuum (28inHg or more) before conversion.

The link you sent me says to add the concentrated sulphuric to the methanol, then into the oilstock. The acid is going to instantly start converting the methanol into dimethyl ether.
(highly volitile/toxic/explosive)

I was under the impression that the acid was to be added very slowly to an agitating mixture of methanol and oilstock to avoid this side reaction.

This message has been edited. Last edited by: Southernyankee,

Southerenyankee

You said: "The acid is going to instantly start converting the methanol into dimethyl ether."

What is your source of this information? Have you tried it?

quote:

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Originally posted by neutral:
Southerenyankee

You said: "The acid is going to instantly start converting the methanol into dimethyl ether."

What is your source of this information? Have you tried it?

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A basic understanding of etherification/esterification points in that direction, but journey to forever's foolproof explanation has a warning about it.

No, I have not and am not in a big hurry to try it. My aversion to a write up in www.darwinawards.com steers me away from stuff like that.

Anyone ever tried catylitic beads?

http://www.rohmhaas.com/ionexchange/IP/fatty_acids.htm

I am going to contact this company to find out what mixtures, temps, pressures they recomend.

Yes I thought you might have got it from Alex. You will know if you have been following this forum that much of what he says is not quite correct. Of course it is possible to make dimethyl ether from methanol and sulphuric acid but I think the conditions required to achieve it are much more stringent than just adding the acid to methanol. I hoped you had found a proper reference.

Let us know what Rohm and Haas says. I have had contact with them over the last year or so and haven't gotten very far.

They had a booth at the NBB convention last week and even there they had very little idea of how to use their product. I specifically asked them for the information that you are looking for and was told that it wasn't available.

Dropout

In consideration of the source, I see your point. Calling any process that complex 'foolproof' is like calling any ship made from steel 'unsinkable'. (Make something foolproof, and somebody comes up with a better fool.)

Also I am thinking from the perspective of CONCENTRATED sulpheric acid and I see from further reading (and I have days of reading archive posts to go) that most of you are using 95 percent; which, probably would not suppourt etherification in any grand scale.

On that subject, why not use concentrated sulphuric? Is the price diffrence that pronounced? Or is it difficult for John Q. Public to buy because of some of its uses in explosives manufacture?

Please understand that my experience in biodiesel is amounts to 1 batch of Dr. Pepper method (pat. pending) I know a bit about chemistry, but that is no substitute for practical application.

quote:

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Originally posted by Dropout:

They had a booth at the NBB convention last week and even there they had very little idea of how to use their product. I specifically asked them for the information that you are looking for and was told that it wasn't available.

Dropout

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The needle on my Horses!#tometer (pat. pending) jumped on that one. 'Not available to a lowly pion like you' I might believe. From reading thier site, I get the impression they deal mostly with multi-billion dollar corporations, who are probably paying them well to play stupid. How do they know it works if they didn't test it? Somewhere they have a set of pressure, temp, concentration curves to show optimal reaction completion.

When they realy are out to get you, paranoia is just sound thinking-- Sigmund Freud

While you may be right although they did have some rather detailed information on using one of their products to purify the esters after reaction.

Their experience seems to be in the ethanol area so I'd bet it comes from Brazil. As a sideline, it's interesting that they use diesel to get separation of the byproduct.

Dropout

The water Girlmark refers to is chemical water that is formed during the esterification reaction.

As the water generates, it reduces the concentration of the acid, so the reaction slows, and eventually - stops.

I've been head scratching on this soapstock thing, too - I've got a bunch of high FFA grease.

I've thought about doing the esterification reaction at about 240 F and 100 PSI (not exactly homebrew territory), flash a little portion of the methanol AND water vapor off the reactor, condense and trap the water, THEN condense and trap the methanol for re-admission to the reaction.

Haven't built any parts, yet - it's still a pipe dream.

Eric K

quote:

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Originally posted by mtushmoo:

I've thought about doing the esterification reaction at about 240 F and 100 PSI (not exactly homebrew territory), flash a little portion of the methanol AND water vapor off the reactor, condense and trap the water, THEN condense and trap the methanol for re-admission to the reaction.

Haven't built any parts, yet - it's still a pipe dream.

Eric K

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If you are looking in that direction, and I hope you have deep pockets, check this out: No acid, no catalyst.
http://bioproducts-bioenergy.gov/pdfs/bcota/abstracts/19/z191.pdf

Supercritical esterification. From the looks of it, you can esterify the ffa and transesterify the glycerides in one step. If I brought that plan to my bosses they would laugh in my face. On the scale I operate the equipment would pay for itself in 6 months, but you still have to come up with the money first.

I am looking for a low-tech approach. Homebrew tech on industrial scale.

Ah yes, the Super Critical method

I think you will find that no one is actually using it to make more than a few ml a time in a lab.

And did I hear the Word "Foolproof" mentioned?
Did I tell you the time that a good mouse friend of mine did some "Deep and Meaningful" tests on that very process?

And the interesting reply to an e-mail about using the "Foolproof" method for high FFA oil from Dr Michael Allen, the fellow Keith claims successfully uses the "Foolproof" method with 20% FFA oil?

Rev Tilly KE (Actor)

actually my understanding is that the supercritical methanol method quietly became commercially viable in the past year and a half. However you're not likely to find it useful for homebrewing, due to the obvious dangers.

Keith keeps telling peopel on the biofuel forum that that is not the case (and I used to spend a lot of time gloating about the 'few milliliters made once in a lab, quit being overexcited' bit too), but a friend of mine who is in the biodiesel industry was shopping for a plant a year ago, and they found that one of the (more reputable) Austrian plant builders have a working plant based around the supercritical process - which you can buy for several million dollars or somethign equally prohibitive.

People who were at this year's NBB event might know more- the company was exhibiting at last year's event though they were somewhat quiet about the fact that the process involved supercritical methanol. They already have another well-proven plant process and have been in the business for a while. And no, it's not Camillo H. and "Energea".

Mark

This message has been edited. Last edited by: girl mark,

Acid route via esterification can be conducted using either metal catalyst or acid catalyst.
Palm based material with IV>60 can be an option as feed material.
Interested to know anyone using this route to produce Biodiesel.

Girl Mark, are you referring to Capital-Technologies? They use very high temperatures but also a couple of different solid state catalyst.

no, I think it's a different company.

Mark

can anyone tell me what keep the bio that you have just made with the supercritical method from detonating in the reactor?
i dont belive the diesel engine runs at anywhere near that kind of pressure and temp
looks to me like a highly scientific bomb waiting to happen

tom

quote:

Originally posted by tom s.:
can anyone tell me what keep the bio that you have just made with the supercritical method from detonating in the reactor?
i dont belive the diesel engine runs at anywhere near that kind of pressure and temp
looks to me like a highly scientific bomb waiting to happen

tom

No oxygen.