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Can Someone Explain Methanol Recovery To Me?
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As most of you know Methanol is the most costly portion of making Biodiesel and I know for a fact that after I react a batch there is always some condensed methanol on the underside of the lid of my processor when I remove it the next day.

I know nothing about how to re-use that methanol in another batch or for that matter extract any other methanol left the biodiesel / glycerol on the bottom.

Is there a step by step process to explain how this works and how to make something to recover the meth?

How much is actually recovered? I use 10.3 liters of methanol for my 47 liter batches. How much of that would I recover?

Thanks in advance!!

Clint


My 4x4 Website: http://www.4wheeling.ca
 
Location: Vancouver Cananandanada | Registered: June 14, 2008Reply With QuoteReport This Post
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Its really pretty simple to me, now that I do it. You bring the glycerol up to a temp that boils out the methanol. Those vapors travel to a condenser, usually copper pipe or radiator type set up. The set up cools, which turns the vapors back to liquid.
Me, I use my processor vent(all steel) whch goes to a copper coil ina 5 gallon bucket. In that bucket is flowing cool water. Just enough to over flow the bucket. Kepps the water cool. Bottom side of the copper line attatches to a line that goes into a collection vessel. In my case a 55 gallon methanol drum.
Methanol in glycerine starts to boil out at 147 degrees. as you get more methanol out, the temp starts to climb. Once my temp gets to 190 degrees, I call it done.
 
Registered: May 13, 2008Reply With QuoteReport This Post
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You are using 22% methanol in your process.
Your process uses only about 16%; the excess methanol is used to guarantee a good conversion.

In theory you should be able to recover some 25% of the initial methanol used, but in practice it's around 15 -20% (which is no chickenfeed!)

You will need a still or set up your processor to be used as a still.
Both methods are described here in the Methanol recovery forum.

By far the most of the methanol will be in the Glycerine by-product and just a bit in the freshly processed BD.
However, it makes sense to get the Methanol out of the BD as well, because it releases the soap left in the BD.

I'm not going to tell you how to do things, there are very good posts here that describe the process better than I could.

Good luck!
 
Location: Ireland | Registered: May 28, 2008Reply With QuoteReport This Post
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quote:
You are using 22% methanol in your process.
Your process uses only about 16%; the excess methanol is used to guarantee a good conversion.


The process uses about 12.5%. The rest is excess.


Andrew

http://biodieselcommunity.org
03 Dodge 2500 B100 homebrew
79 Rabbit B100 homebrew
 
Location: Northern California | Registered: February 27, 2006Reply With QuoteReport This Post
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Yes, with the exception of canola oil (11.3%), butter (13.6%) and coconut oil (16.3%), 12.5% is a good round number for the other oils.
 
Registered: February 10, 2009Reply With QuoteReport This Post
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I use Canola, so why would I not want to just react with say 12% rather then 22% and allow all that waste? Whats the theroy behind that?

Clint


My 4x4 Website: http://www.4wheeling.ca
 
Location: Vancouver Cananandanada | Registered: June 14, 2008Reply With QuoteReport This Post



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quote:

I use Canola, so why would I not want to just react with say 12% rather then 22% and allow all that waste? Whats the theroy behind that?


The reaction converting oil into BD is an equilibrium reaction. The excess methanol is what ensures that the reaction proceeds in the correct direction. Otherwise, it can stall out and even reverse under certain conditions.

If you like, you can read this article about 2 stage base/base. It explains it in a clear way, I hope.

HTH.


Andrew

http://biodieselcommunity.org
03 Dodge 2500 B100 homebrew
79 Rabbit B100 homebrew
 
Location: Northern California | Registered: February 27, 2006Reply With QuoteReport This Post
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Originally posted by 4Wheeling:
. . . why would I not want to just react with say 12% rather then 22% . . . .


In addition to the equilibrium of the chemical reaction as described above by Andrew, there is a second reason to use excess methanol.

The excess methanol serves as a solvent in which the catalyst resides at the end of the reaction. The catalyst is then removed with the methanol from the finished biodiesel. Some of the methanol with catalyst partitions into and is removed with the glycerol, the rest is removed with the wash water.

In either case the excess methanol serves as the carrier of the catalyst and allows for the removal of the catalyst.

If there were no excess methanol to keep the catalyst dissolved, then virtually all the catalyst would convert to soap during the biodiesel reaction.
 
Location: Illinois | Registered: February 21, 2006Reply With QuoteReport This Post
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