I am planning on demething my glycerol with a pot made from a 10 gallon air tank that I have. Are there any suggestions on what would be the best way to go to heat it up. I plan on putting 8-9 gallons of prewash inside the tank. Thanks.

i think the safest way to heat that tank would be indirectly, using hot water or steam. of course that would require either double walls or sime kind of heating coil, either inside the tank or welded to the outside. that way the glycerin couldn't overheat.

Why is it that you want use distillation to recover the methanol from your glycerin?

-Jim

quote:

Originally posted by Jim D:
Why is it that you want use distillation to recover the methanol from your glycerin?

-Jim

is there another way to recover methanol?

The main reason I want to demeth is to make soap with my glycerol. From what i've been reading, the methanol can also be reused for future batches mixed in with the new stuff. I am wondering if the 35000 btu propane portable food burner from northern tool would do the job. It would be easy to use, and the heat output of the burner is adjustable. Only down side I guess would be that the recovered meth would have to be pretty far from the flame. Anyone use a burner?

Holy S#%T! dont even think about it! Here is my still i use one 5500 watt 220 volt heating element, a slong as the element is always covered you will have no problems.

How long does it take to demeth a batch with the element? I was also wondering what type of tread do the heating elements use, assuming I can just weld it into the tank.

It takes around 10 hours to demeth 40 gallons, i just use 1 inch half couplings with the rubber gssket that come with the elements, and have never had a leak, even after distilling you will have some meth left that will need to be boiled off, but this you can do over a gas flame becasue there is a very small amount left,
I have found it is very difficult to make soap with KOH glycerine, not entirely sure why but it seems to hold onto a small amount of methanol and this causes a lot of grief when making soap.

The reason I ask is because you can remove the methanol and use it in the process by mixing the fresh glycerin in with your next batch of oil. Heat to 130F and recirculate for an hour or so. Then allow the glycerin to settle, and drain it. At that point most, if not all, of the methanol will have been used up reacting with your next batch of oil.

Methanol recovery and reuse without distillation.

-Jim

[QUOTE]Originally posted by Jim D:
The reason I ask is because you can remove the methanol and use it in the process by mixing the fresh glycerin in with your next batch of oil. Heat to 130F and recirculate for an hour or so. Then allow the glycerin to settle, and drain it. At that point most, if not all, of the methanol will have been used up reacting with your next batch of oil.

this is a very confusing post, I think you mean remove the glycerine and use it to pretreat your next batch without distilling the methanol, right?

Your still is sweet!! The good thing is that I use Naoh, so i'm hoping I can get some decent soap. Now with the 1 inch coupling, can I use any type of water heater element, or does it have to be a particular one? I seen lowes has 4500w elements for less than 10 bucks, which sounds good to me. I guess i'm going to try and make a reflux still, but I'm debating on the easiest way to build it.

quote:

Originally posted by Jim D:
.... you can remove the methanol and use it in the process by mixing the fresh glycerin in with your next batch of oil. Heat to 130F and recirculate for an hour or so. Then allow the glycerin to settle, and drain it. At that point most, if not all, of the methanol will have been used up reacting with your next batch of oil.
-Jim

A very interesting concept. How do you know though, the quantities of methanol and NaOH to use once the added glyc has been removed. The amount of methanol and lye in the added glycerine is variable and titration after glyc removal is meaningless.

Nick

quote:

Originally posted by superbio:
Your still is sweet!! The good thing is that I use Naoh, so i'm hoping I can get some decent soap. Now with the 1 inch coupling, can I use any type of water heater element, or does it have to be a particular one? I seen lowes has 4500w elements for less than 10 bucks, which sounds good to me. I guess i'm going to try and make a reflux still, but I'm debating on the easiest way to build it.

Any element will work, you can also get one of the flange mount kits they sell for them, cut the flange off and just use the threaded section that the element screws into, this works well also.

quote:

Originally posted by Fabricator:
this is a very confusing post, I think you mean remove the glycerine and use it to pretreat your next batch without distilling the methanol, right?

Exactly.

quote:

Originally posted by Twenty4Seven:
A very interesting concept. How do you know though, the quantities of methanol and NaOH to use once the added glyc has been removed. The amount of methanol and lye in the added glycerine is variable and titration after glyc removal is meaningless.

Nick

I don't know, and it does not matter. I titrate my oil then pretreat with the raw glycering from the previous batch. I let it settle and then use the same amount of methanol and lye that I would have used without pretreatment. The extra excess methanol is just going to get used in the next batch anyway. Lye is cheap, so a little extra is not a big deal.

Hi Jim D

That's what we are doing too !

It works great with the Canoe Paddle Processor !

We are right now deep into the study of this !

We will post test results on biodieselnow.com in the Canoe Paddle Processor thread !

http://www.biodieselnow.com/forums/t/19664.aspx

Thanks, Steve

OK,I thought the pretreatment was to help lower the FFA in the oil,and the moisture content. IF this was true, wouldn't the titration of the oil be different? Also with the pretreatment glycerol, Does it get rid of all the methanol, or does it still have to be distilled to get soap worthy glycerol?

The titration should be different, but I don't know if the test would be accurate. In my case it really does not matter. Worst case I am over applying methanol. Normally the drawback of that is that you are wasting an expensive ingredient. Since I turn around and use it in the next batch by pretreating I really don't care if I am over applying. (BTW, I use 20% methanol.)

Does it get rid of it all? I have not tested that yet. My guess is that there will be so little left in the glycerol that your best bet is to just boil it off. If you already have a condenser you can distill it, but it should take MUCH less time.

The last batch I checked (not my batch, a friends) was 35 gallons of WVO, 9 gallons of raw glycerol, 125 deg F for 1.5 hours in an appleseed processor. The resulting glycerin drain was 7.5 gallons. That means he "recovered" at least 1.5 gallons. Probably more since the pretreating created additional glycerol.

-Jim

I think it beats base/base two stage because you can end up with high conversion biodiesel will low soap.

It lowers the FFA content so you can use less lye in the process and still make high conversion biodiesel.

It gets the reaction started and recycles the methanol and lye plus cleans the oil.

The oil looks way clean after pretreating it this way !

Trying to use less methanol means less and trying to use less lye means more !

High conversion, low soap biodiesel is the stuff ! ! !

With this method I'm guessing that there is no reason to use a 5% prewash right? Also would it be true to assume that the difference in wvo amount in the processer is methanol, so just add the difference to make the full reaction? Anyone just try to make soap without distilling the glycerol after the pretreatment? Thanks