Has anyone tried to recover methanol from glycerol/fats/waste water?
I'd be interested to know the method used and the percentage of recovery.
We have a still and will try the recovery, but any info before we start would be helpful.
thanks, Ani

You need a still similar to those used for ethanol (booze). Look at www.journeytoforever.org

As the biodiesel byproduct is very fatty direct heat or electric elements are too fierce. You'll need a hot water coil or hot water bath running at about 85C.

Meth boils at 65C, but the extra 20 degs needed to overcome methanol's large latent heat of evaporation.

For personal safety (methanol is toxic and flammable) make sure the system is sealed and that cooling system is working before applying any heat.

Biodiesel uses about 8% methanol and you can get 1 to 2 percent in the ester so anything above that should be recoverable.

Hope this helps.

Has anyone had experience distilling the methonol out of the finished biodiesel? at 2% of 50 gal that is 1 gal not so much I guess but it would be neet to conferm the methonol content. Otherwise the Meth is going out with the wash water which as simon suggests (using KOH and phosphoric acid) would make a dilute fertolizer. What is Methonol's effect on the grass?
I have in my posession but not set up yet an electric water heater I intend to use as the boiler for my still what is the big deal about using an electic element?
cool

Terry M

I finished running a batch of oil through my new processor two weeks ago, and for the first time recovered the methanol from both the fuel and glycerol layer.

Recovery was accomplished using an electric heating element (really a pretty wimpy one - 1500w) and a vacuum pump. Using vacuum during distillation really simplifies matters. One must have, of course, a sealed vessel like an old water heater. It should be thoroughly air tight, not only for efficiency's sake but also safety's sake. It should be hydrostatically tested before use (really not that hard to do) and well insulated.

The condenser need not be complicated. Mine is simply one 1/2 in. copper pipe, about three feet long, jacketed with a 1 in. copper pipe, with the fittings necessary to feed cooling water into and out of the jacket. It worked well.

I used the tank as my mixing vessel, using a powerful centrifugal pump to circulate the oil and methoxide. Reaction temp was about 55 degrees C.

Once I had determined that separation had begun, I turned on the vacuum pump which was connected to a liquid trap which was connected to the outlet end of the condenser which was connected to the tank.

I had begun the reaction using about 14 liters of methanol. Within two hours, I had recovered six liters. Very little added heat was required, but temperature must be maintained. The boiling methanol will cool everything quickly. Cold water is needed for the condenser. That wasn't much problem this time, but I forsee problems next summer.

Temperature and pressure aren't critical. The difference between vapor pressures of the methanol and the ester is so great that there is no chance of distilling any ester. There may be a little water in the mix, but I didn't detect any. Whatever combination of heat and pressure required to boil the ethanol is ok.

Vacuum is magic. Filtering the oil, loading the vessel, putting in the methoxide, drying the ester after washing, everything was a snap. The first batch was really fun.

VP

GO PUP! Sounds like a very neet system.

How do you fill you mix/reaction tank with the WVO?
How do you add your methoxide?

What vacuum pump do you use?

What kind of centrifugal pump do you use?

For hot summers, would a long coil of copper tubing run through the freezer compartment of an old refrigerator help?

Got pictures?

I really do like the idea of your fully enclosed reaction/mix system!!

I should give a full description, and I suppose this should be in the equipment section. Look there under the touchless processor heading.

V-P

[This message was edited by Veggie Pup on 11 January 2001 at 11:17 PM.]

I think the only bit you need to be concerned about is that too much vacuum could lower the evaporation and condensation point too much so that the cold water is not cold enough.

Somebody once suggested that the vac pump exhaust could be fed into a suitable fluid trapping system. I presume that the expanding exhaust would chill enough to condense the methanol. The snag is that the methanol spray could easily be carried out with the vac pump exhaust gases so you'd need to be careful.

Do watch out for the element burning out or overheating. As it's not designed for poor energy conductors like soap and FFA, it's quite possible to get locally very high temperatures, maybe enough to evaporate the FFAs and other oils in the byproduct tank.

Good luck and well done

Pup:
how much vacume do you pull?

what is your reaction temp in F?

do you dewater with vacume?

what type of vacume pump do you use and where can I get one?

do you have any pics of your new set up?

p.s. YOUR MY HERO. I'd love to pick your brain some time.

Please note that there is a fairly new, entirely separate section totally devoted to methanol recovery. This thread would be a valuable addition to that discussion, and you may find other exciting tidbits over there:

http://biodiesel.infopop.cc/eve/forums/a/frm/f/4441089311

Finest regards,

troy

OK, I"m moving this thread over to the Methanol Recovery forum.

Mark

Here is a new active thread. Find more on this topic on the new Methanol Recovery forum. Good move girl mark.

Yesterday I made a 50 gallon batch of BD using 50 gal of DRIED and FILTERED WVO, 10 gallons of methanol and the appropriate amount of KOH (7 grams plus titration per liter) at 140 F. After the reaction, I put a 27 inch of Hg vacuum on the BD and byproduct mix. I recovered 3.75 gallons of meth. The BD turned out great, but I can't determine if there was any revearse reaction because I ended up draining off too much good BD when I was removing the glyc. One additional observation: The glyc was so thick after removing the meth that I had a hard time pumping it out of the reactor with a 1/2 horsepower pump.