I have a thought to use a vacuum vessel and pump down the reacted volume of materials and then pass a coil of line through a cooler to recover methanol. Think it would work?

 

Yes it will its called a condenser and the vacum will lower the "boiling" point of the methanol. The vacum will reduce the amount of heated need to get the methanol vaporized. You should only do the with the BD and the glyc seperated though as I have heard you can reverse the reaction if you do this with the two still in the same container. most of the methanol is contained in the Glycerine from what I understand.

Fabman can probably help you out more.

 

Works just fine! I've been using vacuum for a couple of years now. There are pics of my "vacuum still" in my gallery. It started as a heated still, then I changed to straight vacuum.

I recover the methanol from my biodiesel and my glycerol. Total recovery from both is close to 45%.

 

Thank you. How do I find your gallery fabmandelux?

 

Just click on his name at the top of his post. Drop down box with choices.

 

Fabman,
How much methanol do you recover out of the Bio itself? I have been recovering the methanol from the glycerol with good results and was wondering if it was worth building another system just to recover the methanol from the bio. I only process 40 gal at a time. So out of that 40gal, approx. how much methanol could I except to yield.

 

I'm getting between 12 to 14 percent from my bio, so a 40 gallon batch I would expect around 5 gallons of methanol.

Even if it cost me $.05/ gallon I would still do it. By recovering the excess Methanol FIRST, all the soap falls out of suspension and can be simply filtered out.

At this point I recover 41 to 45 percent of my total methanol input, I think I can do better................

 

What kind of pressure and temperature do your stills operate at? I thought it might be possible to recover methanol at room temperature under vacuum and then begin heating the bio, change out the methanol recovery container for a water container and dry the fuel. Fabman- the soap can then be subsequently filtered? This sounds like a bonus!

 

It sounds as if you are running your reaction short, or you are recovering other stuff besides methanol..

A 40 gallon batch at 22% meth is going to be just over 8.8 gallons of methanol into the reaction. You are claiming you are getting back 5 gallons of that?

Doesnt sound right.. but then again, I'm assuming 22% and you could be using 30% for all I know.

One thing is for sure, 5 gallons back on a 40 gallon batch using commonly accepted methanol volumes doesnt sound right.

My guess is that you are recovering other stuff besides methanol..

Have you checked the purity of your methanol with a hydrometer?

The best type of meth recovering device is a reflux still so you can control the purity of the output.

 

I don't use either my heated still, or my vacuum still anymore. When I built my heated still over 3 years ago I found I had to heat it to about 195 Deg F to get any production out of it. Then I switched over to vacuum, 15-18 inches @ 100 deg. I now use a new system that uses less energy, and is WAY faster.

I also had the wrong figures in my earlier post, I don't do 40 gal batches, I do 50 gallon batches. It should have said...........

50 gallons WVO
10 gallons Methanol [20%]

Total Methanol recovery from 10 gallons of Glycerol: 2.5 gallons/ 25%
Total Methanol recovery from 50 gallons of Biodiesel: 2.0 gallons/ 4%
Total Methanol Recovery: 4.5 gallons or 45% of input.

 

Are you referring to your new hydrocyclone technology in your process? I am very interested in this as well. We recently tried an old huge worn out centrifuge with no luck. Once we fixed one thing- something else would break- too many moving parts with all the maintenance woes made it a boat anchor.

 

Not the same. I've found the hydro-cyclone is to sensitive when used with waste oil, but works fine with virgin oils. I will use it when I process the canola seed I'll harvest in late May this year.

The new Methanol recovery system I'm using is completely different.

 

I couldnt find your vacuum still pics in your gallery and Ive been to the ranch. I need them to convince my dad to help me build that part of our process. Its just not getting across to him or Ive described it wrong. I will make my diagram in paint and post here in a few.

 

Troy, You must be getting blind It's in the first album about half way down
Hang on a little while longer my young friend, and I'll send you the plans for the new system

 

Is this about correct or is my condenser in the wrong location? I cant get my dad to believe that the condenser is before the pump not at the vacuum pumps exhaust. Please correct me.