From what I have read, the beer hydrometer wont do it..get one thats set up for vodka and the like.

Hi farmer.

Glad it worked well for you.

Be careful with the water, if your process cools for any reason, you could end up sucking in a slug of water and that would spoil your recovered methanol.

I shall soon be posting an update to show how you can run a sealed system with the condenser, with no or very little vapour release.

Watch this space...
( posted here... ) Added 26 March 2007

The condenser has no reflux itself, but can have a reflux stage added.

Basically, reflux consists of a short, wide, vertical tube coming off the top of your heating pot, say 10" long, 3" wide. It is filled with bits and pieces, often marbles or short lengths of 1/4" tube, which allow the vapours (especially the water vapour) to condense and fall back into the pot. The top of the reflux column connects directly to your plumber's delight condenser, any uncondensed vapour making it this far, and then on thru the condenser, should be high purity methanol.

Reflux adds a lot of time and energy to the distillation process, but yields a higher purity result.

I don't use reflux because I don't mind a small amount of impurity - I just add the recovered amount to around 14x fresh methanol and use in the next batch. I only run to 90 degrees C - beyond that I get a lot of water, as I do the 5% prewash.

Hope that all helps.

Best regards,

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

what about doing the methanol recovery at the end of the reaction cycle before prewash to kill 2 birds with one stone?

If glycerin and biodiesel are present in the same container when the heat is applied it is possible to reverse the reaction, or so I am told.

-Jim

Hi Locknut

That is an interesting proposal.

As Jim says, the risk of doing methanol recovery with glycerine and biodiesel together, is that the heat energy CAN cause SOME of the glycerol to re-join with the fatty acids, displacing the methanol.

The effect of this is, it could reduce conversion, turning methyl esters (biodiesel) back to glycerol esters (veggie/animal oil).

Now, I don't recall seeing anywhere a statement of how MUCH conversion loss would occur, and, if we've done a 5% prewash, the effect may be reduced enough to make this procedure successful.

So, I will try your idea on a small batch, because if it does work without too much back-reaction, it would save a lot of work!

More later ....

I didn't suggest it, it was locknut and juliena who proposed it, so three cheers to them if it works!

Hey gang.. getting back to the soap issue that was covered in this thread earlier....

I am using my Plumber's Delight to recover methanol from biodiesel in an appleseed/ waterheater. We drive the temp up to about 205-210 F and then figure we are done. It works great. We are injecting air into the lower plumbing to help things along. We don't have a high temp pump or tubing so we cannot circulate the BD when it is hot at this time. We are making 50 gallon batches of fuel in an 80 gallon heater.

The challenge I am having is that we have been getting some hard soap settling into the lower plumbing of the reactor when the BD cools off. I don't currently have a metal settling tank (we have a poly barrel w standpipe) and I think my Harbor Frieght pump won't handle the heat either.... so we let the fuel cool off before pumping to settling.

Well after the first soap experience (heated the lower tubing with a blow torch) I tried draining a few gallons into a bucket before cooling off the first night. After things cooled off, there was a very solid layer of soap in the bottom of the bucket, perhaps about a liter or more. Despite draining the 3 gallons the night before, I still had clogs the next day. I had to push it out by heating things up and putting some compressed air on the vent tubing up top...

So... solutions? A metal settling tank and High temp pump for draining the reactor before soap setting? Will switching to KOH eliminate the hard soap issue (we are on NaOH now)? Will this soap layer funk up my reactor and next batch of BD? The water heaters don't drain 100 percent well...

Thanks for your comments!
Farmer

Hi farmer

I think you may need to let your glycerol settle a little longer before draining it off - sounds like glycerol settling.

After removing the methanol, the little remaining glycerol drops out fast.

If you are doing a 5% prewash, try letting the glycerol settle 2 hours before you drain it.

If you aren't able to drain it all out of the reactor, don't worry, some can be there when the next batch is added without problems, so long as your piping and pump are free flowing.

Perhaps have all your piping running downhill towards a lower drain, and just leave the drain tap open after the processing is complete. 45 degree elbows help a lot here.

I have the harbor freight blue bomber pump too, and I've pumped WVO at 220 F through it number of times with no observable ill effects. The propellor that pushes the oil is metal, as are most of the parts in there. There is a non-metal seal I think, but it seems to be holding up.

The tubing I used is the standard braided tubing, and it hasn't blown at these temps.

I have a question though. I have the plumbers delight too, and when I did the recovery, it took about 12 hours to get 6 gallons of meth out of it. I did turn the heater off when the vapor temp was around 130 though. Was that too early? What temp should the vapor be, what temp should the glycerin be at?

I don't know the temp of the glycerin though - I have the thermometer, but been too lazy to put it in. Should I?

One more question - I have thought about making the air a closed loop. I.e. the vapor output of the reactor goes through the plumer's delight into the capture vessel which vents into the bottom of the reactor vessel (I have a check valve - the appleseed methoxide inlet). I figure the air will keep moving due to meth continually expanding and going out through the PD. Has anyone tried this?

Didn't actually mean to ask all these questions when I started writing this - I had given up on the recovery after spending 12 hours on the 6 gallons, but maybe I'm just doing it wrong.

Thanks

Hi Paul,

How many gallons of BD is in your tank when you start?

I stop when the tank temperature (liquid) gets to around 200F

I recirculate the air in a closed loop too - see This

I had about 30 gallons of glycerin in the processor.

What is a decent rate of recovery? 1 Gallon an hour? 2 GPH?

thanks for the link.

130C vapour temperature is REALLY high!!

That suggests you have very little methanol left in the glycerol. 6 gallons out of 30 is about right.

Are you spraying the glycerol thru the airspace while recirculating?

Recovery rate will depend on several things, most importantly heat power, amount of volume in the tank, insulation quality and agitation of the fluid during distillation. etc.

It will start fast and get slower as you proceed.

Graham,

Have you had any luck with this?

I have thought of doing this very thing, but was unsure of the ramifications of bubbling glycerine and biodiesel mixed together.

If this would work, then when the methanol is completely removed, the glycerine might even act as a wash that would remove the freed-up soap from the biodiesel.

I use the 5% pre/post/whatever wash.
Thoughts?

quote:

Originally posted by GrahamLaming:
I didn't suggest it, it was locknut and juliena who proposed it, so three cheers to them if it works!

Hi Sid

I have a couple of samples off for GC testing, so we'll see how they turn out.

They showed a little dropout in the 27/3 test, but not bad at all.

As soon as I get the results, I'll post them here.

Cool. Thank you.

A quick question for you though..
What were the conditions of your test samples?Temperature?
Time?
Was it bubbled with compressed air or other?

I know that when my single stage batch reaction is finished the complete mixure is about 140-160degF [60-71deg C].

From taking a small sample of that mixture, and keeping it heated at around that temperature, it took my sample about 15-20mins for all the methanol to evaporate.
I did not check for water content though.

NB here...Am trying methanol recovery after removing glycerine, with plumbers delight attached to an Appleseed processor. All seems to have worked well, however am getting slightly milky color distillate. Recovered about a gallon from a 120 litre batch, down to about 90 after drawing off glycerin (a little too much drawn off..newbie, remember?)

So I poured this gallon into about 4 of fresh, clear methanol and overnight the whole five gallons turned milk white. I suspect a water leak in my Plumbers delight condenser, but hate to tear into it if it is another problem.

Hi Timotheos

That does sound like water is leaking into the centre tube.

Why not leave the water jacket pressurized (put a closed valve on the upper water port) and see if anything drips out of the central tube.

Let us know how you get on.

Good luck

Graham

GL - can I ask you a question about my meth recovery system? It's set up like the diagram on your site, but with the 'venturi' before the pump. It's an appleseed processor that draws in air from the methoxide inlet that is connected to the meth collector.

I.E.

Heat exchanger -> MEth container -> Methoxide inlet before pump -> pump -> Biodiesel container -> Heat exchanger -> etc

The problem is it there is pressure building up in the loop. The water is coming out cold out of the HE, ie it is condensing everything. I have checked as well as I could there is no air leak that is introducing extra air into the system.

Any ideas why there is pressure building up? The air is still circulating - the pump is pumping air and BD up the site tube.

THanks

Thank you very much for the quite elegant "Plumbers delight" Condenser design. I have fabricated two of them now, one is on my reactor. It is pretty near 2 meters long, and the other, almost a meter long, I built just out of sheer joy. I have a picture of the shorter one here, and will post pictures of the longer one as soon as I finish plumbing in the vapor feed and venturi that I also must thank you very much for posting.
Thank you very much, sir.

010408_003ii.jpg (135 Kb, 84 downloads)

How are y'all attaching your plumbers delights to the top of the processor? I don't want to hard plumb mine so that I have more flexibility to move things around. Do you think one of those flexible stainless steel water lines would be OK? I'd form it in a wide arc, but was just concerned that the ridges on the inside might be a problem. I was planning to insulate it all the way around to where the water jacket begins. Am I on the right track? Thanks.