Thanks GL...

Now what am I going to do with that half ton of KOH I just ordered?

Cheers,
farmer

Hi Graham,

I tried out my new eductor and venturi today and would like to pass on what happend in the test tank.

When the pump was turned on and the flow hit the eductor a vortex was created just above the eductor inlet, as I lowered the eductor the vortex grew to a depth of 2 1/2" deep, so with my pump the inlet needs to be at least 3" below the fluid level to stop it drawing in air.

The use of the eductor had no adverse affect on the performance of the venturi delivering meth. but when it came to recirculating the system atmosphere the eductor created an enormous amount of bubbling in the fluid.

I've yet to try it for real but I should imagine that when drying oil and distiling of methanol the bubbles would be a great benifit.

Jim.

Hi Jim,

Sounds good - you should see the backpressure on the ductor inlet rise at it is called on to do more work.

With the suction port blocked off, there should be little backpressure, and as you allow material to bleed into it, the work being done will create a backpressure. You can see this with a simple manometer on the main flow feed to the eductor.

Keep up the good work!

A new, simpler version is shown below...




Full description at ...
http://www.graham-laming.com/bd/ecosystem/state_diagram_new.htm

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

Thanks for the diagram GL as we are retooling this week...

So a few comments/ questions for clarification...

Here the methoxide or water is feeding in before the pump as in the conventional appleseed design. By raising the carboy above the pump, I assume this would deal with the grundfos pump's incompatibility with air? I can forsee "burping" the methoxide tubing up into the carboy, so that most of what draws into the pump is just fluid.

I know there has been plenty of dialog on the forum about not raising the carboy for safety, but in practice we always end up picking up the carboy to get the final drainings out anyway and to agitate when dissolving NaOH... I feel comfortable with lifting it onto a safe rest a foot or two above the pump in this case.

Is your vent, pictured at the top of the diagram, manually valved? Currently we have a tee with valves to direct excess pressure or vacuum either through the exhuast vent or through the condensor. Or are you using the U-tube pressure indicator pictured at your site?

Lastly do you have the condensor connected and open all the time? We have only been hooking ours up when we intend to distill methanol, although "Project Purity" was at our shop last week and he said he gets output from his condensor whenever he adds methanol to the warmed oil.

Thanks for clarifying. I have been promoting this design to various people we work with and it will be great to give it a test run this week..

Cheers,

Farmer

Hi Farmer

Don't put a valve on the vent. Always leave the vent open. There is no need or benefit to closing it. You won't draw in air and you will lose the tiniest amount of methanol, provided you hook the system up as I've shown in the diagram.

The diagram shows everything, and if you click on the link below the diagram you can see the valve settings for each stage of the process.

As you pump methoxide into the tank, the air displaced does NOT go out the vent. It goes thru the condenser and into the methoxide tank.

Process at 60C / 140F or less and you will get minimal venting.

The condenser is always connected. I recirculate water from a 45 gallon drum, so use no water in total.

The water circ. pump (a Grundfos 15/50) can be set to a slow trickle, so uses minimal energy.

The U-Tube is unnecessary and undesirable in this configuration. You want the vent completely free and open at all times.

You won't lose any methanol if you process at 60C / 140F or less.

As to the methoxide injection, this scheme seems to suit most folks already happy with it in their appleseeds. You could still use the venturi as the methoxide injection port. I'll post another pic to show how to do that, if you'd prefer, probably next week.

Any questions just feel free to ask.

I'm off travelling around France doing tradeshows all next week, so won't be able to get onto the forum, so please excuse any delay in replying to questions.

Good luck!

Brilliant GL... it took a while of studying the diagram for the design to really sink in, but I'm getting it!

So everything vents through the condensor... got it!

Thanks too for posting the new state diagram, that really helps to make it clear.

Have a good trip and I'll try to report back after we reconfigure and give it a try.

Best regards,
farmer

Graham. I am nearly ready to give this a try, and it will actually be my very first batch of biodiesel.

I have made an apple turnover processor, with the harbor freight pump for circulation. I plan to add air during methanol recovery in the bottom through the pipe network.

With my apple turn over there is one 3/4" port that will serve as my vent/condensor output. I could tee it so that it splits to the condensor or to a vent. Would it be advisable to do this with one side of the tee going to the plumbers delight and the other side of the tee going to one of those automatic pressure relief valves? It seems that leaving the other side of the tee open to atmosphere would allow the methanol vapors to go that way instead of to the condensor. If for some reason the condensor became blocked then the relief valve would be available to release a pressure buildup if one were to occur.

Graham, send me your photo and I will hang it in my bd room !!

One of your posts opened my eyes: why spending weeks for methanol to leave my bd when I can provoke it heating the bd inside the processor ? (while recirculation).

One question.
Once my 65 litres processor is full after reaction there are 10 litres of capacity left.
If I heat and recirculate over 75ºC let´s say, and leave a vent open to the outside, will I force the methanol-gas to leave the drum ?

At this moment I am not capable of working on a condenser or anything similar, so I will be guilty for releasing some gases to the atmosphere, I assume it.

Should I install any kind of fun in the reverse shift in order to extract that gas? I guess this is dangerous....

I have read about your ventury tube but have no time to work on one of them now. ....

Any idea ?

Best regards, thanks indeed for your contributions and help.

quote:

Originally posted by GrahamLaming:

As you pump methoxide into the tank, the air displaced does NOT go out the vent. It goes thru the condenser and into the methoxide tank.

Process at 60C / 140F or less and you will get minimal venting.

The condenser is always connected. I recirculate water from a 45 gallon drum, so use no water in total.

The water circ. pump (a Grundfos 15/50) can be set to a slow trickle, so uses minimal energy.

You won't lose any methanol if you process at 60C / 140F or less.

For those of you that want to push the reaction speed by heating to higher then 60c / 140F, it would be very simple. Just add a valved line which connects the vent from the tank to the vent / venturi V7 line, and add a valve to shut off the exterior vent. This would allow the system to pressurize due to the venturi's vaccum and would in turn pull the methanol that boils off, back to the venturi where it where it remixes back into the oil at a higher temperature where it can react again.

quote:

As to the methoxide injection, this scheme seems to suit most folks already happy with it in their appleseeds. You could still use the venturi as the methoxide injection port. I'll post another pic to show how to do that, if you'd prefer, probably next week.

The methoxide / water intake on the intake side of the pump would work fine, as it always did, but I personally believe that you would get better atomization and mixing by using the venturi to mix the methoxide or water, just due to the physics side of the pressure changes that take place inside the venturi. I may be wrong. The pump's impellor does serve to help create some mixing as long as you are mixing slow enough.

Thanks Dave.
I need to take methanol gases away from my reactor without
- a ventury
- a condenser

is it possible ?

If I heat my processor to 90ºC, -let´s say- ,methanol will evaporate and will occupy the empty portion of the drum.
If temperature lowers, it will liquify again and will mix with BD again, I guess, that is why I want it out of the processor, any suggestion?
Best regards

quote:

Originally posted by ANGEL GARCIA:
Thanks Dave.
I need to take methanol gases away from my reactor without
- a ventury
- a condenser

is it possible ?

Sure it is possible. People have done it for ages without these gadgets, the venturi just makes the process more efficient and the condenser allows you to recapture the methanol so that it can be reused, saving you money.

quote:

If I heat my processor to 90ºC, -let´s say- ,methanol will evaporate and will occupy the empty portion of the drum.
If temperature lowers, it will liquify again and will mix with BD again, I guess, that is why I want it out of the processor, any suggestion?
Best regards

Sure, pressurize the system by adding an aquium air pump which would add air that will carry off the vaporized methanol. Having the air bubbling it up through the oil would help make the removal process more efficient. Continuing to pump the oil while heating it would also help.

Make sure that you vent it to the outside and away from your work area, as fumes are toxic.

Ok, thanks a lot

Angel, as soon as you heat the fuel over the boiling point of methanol (roughly 65 C) the gas will begin to leave your reactor. Actually gasses of some kind will leave your reactor before 65 C.

If you hook up your vent to a tube of some sort and run it out doors, the gasses will go out of your shop that way. If you put the end of the exhaust tube in a bucket of water, you will see bubbling in the bucket as thermal expansion occurs in your reactor.

Absolutely you must pipe the flammable and toxic gasses out of your shop and away from you as a minimum.

The gas coming out of the exhaust tube will be hot, so you'll want to use something heat tolerant for your tubing.

It may be true that the methanol gas will dissolve in the water in your bucket. Would anyone care to verify this?

We also have removed more methanol from the heated fuel via bubbling with air, as Dave mentioned. I would advise using a one way check valve on the air inlet port if you are pumping air up from the bottom of the fuel. That way the fuel will not escape or foul your air pump if something goes awry.

Lastly, I have no previous soldering skills and we built a "Plumber's Delight" condensor in about 2 hours. It is a great device and totally worth the time and $ spent to make it. So far we have recovered about 10 gallons of methanol with the condensor, which nearly pays for the cost of the materials. If you are heating the fuel to drive off methanol but not recovering it, it is energy lost as well as pollution.

There is plenty of great info on the Plumber's delight and other simple condensors over at the methanol recovery forum.
Cheers,

Farmer

Thanks for your message, Farmer.
It is very optimistic and makes me look at this problem with better eyes. I will try to build a condenser in two weeks, its a challenge for me, as I have never been specially handy , but if you say it is not difficult, I will try.

Thanks a lot, best regards.

[/QUOTE]
_______________________________________________
originally posted by Dave Calkins

For those of you that want to push the reaction speed by heating to higher then 60c / 140F, it would be very simple. Just add a valved line which connects the vent from the tank to the vent / venturi V7 line, and add a valve to shut off the exterior vent. This would allow the system to pressurize due to the venturi's vaccum and would in turn pull the methanol that boils off, back to the venturi where it where it remixes back into the oil at a higher temperature where it can react again.
_______________________________________________

if you are going to block off the vent, do it before the condensor and make sure there is a 30 psi pressure relief vented to the outside. I believe the idea of letting the pressure inside the reactor to build is to raise the boiling temp of the methanol so it stays mixed with the oil.

Angel if nothing else exhaust your methanol fumes into a drum of water. The water would cause the methanol to cool and then you'll have methanol in your water, but to dispose of that down the drainage system is a lot beter then spewing methanol in the air. Even if you just leave the drum open and let the methanol evaporate with the water it will be better because it will not be a concentrated release into the atsmophere that someone might walk through.

Logan Vilas

quote:

Originally posted by ANGEL GARCIA:
Thanks for your message, Farmer.
It is very optimistic and makes me look at this problem with better eyes. I will try to build a condenser in two weeks, its a challenge for me, as I have never been specially handy , but if you say it is not difficult, I will try.

Thanks a lot, best regards.

I just built a condenser and the hardest part was filing the tee fitting so the 1/2 inch pipe will slide all the way through. I used a small die grinder to do that, but a rat tail file will also work.

quote:

Originally posted by Dave Calkins:

... and add a valve to shut off the exterior vent. This would allow the system to pressurize due to the venturi's vaccum and would in turn pull the methanol that boils off, back to the venturi where it where it remixes back into the oil at a higher temperature where it can react again.

Angel,

One other thing to note:

You don't have to add a valve and close off the vent in order to get recyling.

Having a valve on the vent, can be a mixed bag. I can keep methanal from venting out of the processor and allows you to pressurize the system some which keeps the methanol in suspention at a higher temperature. On the other hand you have to exersize more care, making sure that the vent valve remains open during most of the process, ie heating.

It is best to not have the heater on during the processing. That way you don't potentially over heat, over pressurize, risk a potential tank fire or rupture, etc.

The vent is there for a reason, safety. the time gains are not significant over 60 deg C. It takes twenty minutes to process at 60. What is the point of using a pressurized and potentially more dangerous system to save ten minutes off that? You need time to get everything mixed up properly anyway. I have done it just for the crack but would not do it again now my curiosity has been satisfied.