quote:

Originally posted by Tilly:
Hello Gary,

If you vent to the outside there is no need to have a valve on the vent other than perhaps keeping bugs out of the reactor between batches. A bit of mesh on the outside opening would stop that.
Of course if you are using the reactor as a still you will need to be able to close the vent.
It sounds like your pressure relief valve discharges into your work area. A couple quarts of methanol shooting out of the safty valve into your work room is not desireable.
It would be safer to have it vent to the outside too.

Also, if you are pressurizing your reactor metal plumbing is less likely to rupture than Rubber/Plastic hoses.

Having seen the higgeldy piggeldy design of some of these reactors with a myriad of valves everywhere, I suspect a lot of valves are put in the wrong position from time to time.
A written checklist like pilots use would probably be beneficial and a lot safer.

quote:

Originally posted by Garybio:
Last night when I was doing my water pre-wash and I was adding the hot water into my steel water heater processor and I forgot to open the top valve which vents to the outside of my building and the pressure relief valve (30 PSI) I got from Graydon triggered and shot a couple of quarts out. It really scard me at first thinking one of my hoses ruptured but I was glad to know what it was. That just goes to show you using a steel water proscessor tank with the correct relief valve adds safety. I do want to thank everyone out there for starting me off on the right foot.

If you don't have a valve on the vent what will keep you from evaporating the methanol during reaction ? This can amount to a fairly significant loss of methanol that has the potential to have an adverse effect on the reaction . Not to mention you will be venting methanol to the enviorment and that could be dangerous in some situations . There is no reason to leave the vent valve out of the design , you just need to remember to use it . As for the number of valves used in any given system , you should see a real refinery . Those people have valves to isolate thier valves .

quote:

Those people have valves to isolate thier valves .

Seen that , chemical plants too
Gary , go to the hardware store and get a roll of orange or red flagging tape and tie a long piece of it to your valve handle , so it hangs down where you can see it this should help jog your memory to open the valve . Did something similar to stop a friends wife from backing through the garage door with it down . It works well as long as he remembers to replace it when it falls off
Dan

Hello Dodgeram

Have you measured the flow of methanol vapours out of an Appleseed reactor vent tube to verify your claim that "This can amount to a fairly significant loss of methanol that has the potential to have an adverse effect on the reaction"?
Methanol vapors are heavier than air.
There is no airflow through the reactor and virtually no pressure builds up in the reactor so there is nothing to move any gasses out of the reactor other than the slight increase in temperature caused by the initial reaction.
The minimal amount of methanol vapors that might make it to the vent pipe will condense out in the the vent pipe and drip back into the reactor.

I did not say to leave the vent pipe out of the design, just that if you are venting it to the outside it does not need a valve unless you wish to use the reactor as a still or unless you wish to run the reaction above 70deg C.

As far as I can tell, about the only time you will likely vent methanol to the Atmosphere is when you are adding Methanol to the reactor and the official instructions are to "Open the Vent"
So it seems you spend the first 20 minutes adding methanol to the reactor and venting methanol to the atmosphere and then when you are finished venting methanol to the atmosphere you shut the valve.

I have seen a real refinery. I do not think of an Appleseed Reactor when I think of a real refinery.

quote:

Originally posted by dodgeram:
If you don't have a valve on the vent what will keep you from evaporating the methanol during reaction ? This can amount to a fairly significant loss of methanol that has the potential to have an adverse effect on the reaction . Not to mention you will be venting methanol to the enviorment and that could be dangerous in some situations . There is no reason to leave the vent valve out of the design , you just need to remember to use it . As for the number of valves used in any given system , you should see a real refinery . Those people have valves to isolate thier valves .

No Tilly I have not measured the output of a reactor that is being used in an unsafe manner because I try to use my equipment in a responsible manner . If you wish to use a pocessor that is not sealed to idiot proof the process then that is your right , but I think we should try to avoid advising others to do things like that . I think the members who have been here long enough to see all of the possible mistakes that are possible should try to help newer members from maknig the same mistakes , after all that is why this site is here isn't it ?

Tilly,
You ask dodgeram if he can back is claim... Fair enough question.

quote:

Have you measured the flow of methanol vapours out of an Appleseed reactor vent tube to verify your claim that "This can amount to a fairly significant loss of methanol that has the potential to have an adverse effect on the reaction"?
Methanol vapors are heavier than air.

Do you have measurements to prove that it can't cause a problem for the reaction? For example, have you run batches in an appleseed with 16% methanol with the vent open the whole time and still gotten the reaction to pass 3/27? Some other proof?

quote:

I did not say to leave the vent pipe out of the design, just that if you are venting it to the outside it does not need a valve unless you wish to use the reactor as a still or unless you wish to run the reaction above 70deg C.

Andrew

Hello Dodgeram

Who has determined that it is safe to vent methanol to the atmosphere over the 20- 30 minutes that methanol is added to the reactor but it is then unsafe to leave the vent open after virtually all of the methanol that will be vented is already vented.

It kind of sounds like the
"It is safe to mix methanol and lye in a plastic container but unsafe to make biodiesel in a plastic container" argument.

Just to clear this up, you feel that most people who will use an Appleseed are idiots and need to be given inaccurate information to try and keep them safe.
Do you think that accidently shooting a few quarts of methanol into your work area because you have a pressurised a system that does not require to be pressurised is safer than leaving the vent open so any accidental pressurization/ venting discharges to the outside?

quote:

Originally posted by dodgeram:
No Tilly I have not measured the output of a reactor that is being used in an unsafe manner because I try to use my equipment in a responsible manner . If you wish to use a pocessor that is not sealed to idiot proof the process then that is your right , but I think we should try to avoid advising others to do things like that . I think the members who have been here long enough to see all of the possible mistakes that are possible should try to help newer members from maknig the same mistakes , after all that is why this site is here isn't it ?

Hello Andrew

I do not know of anyone who has made biodiesel that passes Warnqvest using 16% methanol in an Appleseed.
With the vent tube open during the 20- 30 minutes methanol is being added to the reactor there will undoubtedly be a small amount of methanol vent to the atmosphere.

Because I feel the Appleseed design is somewhat lacking, I have not made one.
However, I have measured the output of a pot still containing methanol, glycerine biodiesel veggie oil after heating it up and turning the heat off.
This is virtually identical to the vent tube of an Appleseed.
Nothing further came out of the condenser. In fact air slowly moved into the "reactor"

If you have done any tests that shows an air flow into and a methanol flow out of the vent tube or a condenser at the same time I would love to see how you performed the test and your results.
It certainly goes against all the physics I ever learned.

quote:

Originally posted by Andrew Morris:
Tilly,
You ask dodgeram if he can back is claim... Fair enough question.

quote:

Have you measured the flow of methanol vapours out of an Appleseed reactor vent tube to verify your claim that "This can amount to a fairly significant loss of methanol that has the potential to have an adverse effect on the reaction"?
Methanol vapors are heavier than air.

Do you have measurements to prove that it can't cause a problem for the reaction? For example, have you run batches in an appleseed with 16% methanol with the vent open the whole time and still gotten the reaction to pass 3/27? Some other proof?

quote:

I did not say to leave the vent pipe out of the design, just that if you are venting it to the outside it does not need a valve unless you wish to use the reactor as a still or unless you wish to run the reaction above 70deg C.

Andrew

Tilly,

OK, so you have no direct data, either. In your test you measured airflow, not if any small percent of methanol continued to be released. Right?

I would think any loss would be small. But, you seem pretty sure for someone who has not actually tested...

quote:

I do not know of anyone who has made biodiesel that passes Warnqvest using 16% methanol in an Appleseed.

Do you read the posts before you respond to them? I posted that result in the Warnquist 3/27 thread a few days ago. The fuel passed washed, but not uwashed. It was 2 stage base/base 80/20 90/10.

I was careful to close the vent though, since I was not certain it would make no difference. Leaving it open may cause heat loss too, no?

Andrew

Hello Andrew

I suspect my test mentioned above is much more menaingful than any test you have performed.

Flow of gas in or out of the condenser was measured. There was none out, only an inflow.

If you have done any tests that shows an air flow into and a methanol flow out of the vent tube or a condenser at the same time I would love to see how you performed the test and your results.
It certainly goes against all the physics I ever learned


Are you saying that the only reason your batch passed Warnqvest after allowing it to sit for a week was because you shut the vent?

Please explain the logic that suggests the liquid in the reactor would cool quicker if the Valve is left open.

quote:

Originally posted by Andrew Morris:
Tilly,

OK, so you have no direct data, either. In your test you measured airflow, not if any small percent of methanol continued to be released. Right?

I would think any loss would be small. But, you seem pretty sure for someone who has not actually tested...

quote:

I do not know of anyone who has made biodiesel that passes Warnqvest using 16% methanol in an Appleseed.

Do you read the posts before you respond to them? I posted that result in the Warnquist 3/27 thread a few days ago. The fuel passed washed, but not uwashed. It was 2 stage base/base 80/20 90/10.

I was careful to close the vent though, since I was not certain it would make no difference. Leaving it open may cause heat loss too, no?

Andrew

After reading this entire thread, I've drawn conclusions about two important safety questions I had, and welcome your feedback:

1) Plastic vs. Metal
Conclusion: Plastic has a lesser fire rating (time until failure) than metal. Plastic's failure is melting (spilling contents, potentially spreading fire uncontrollably), while metal's failure could, under extreme circumstances (which have yet to be adequately defined here), include explosion.
IF using plastic tanks, they should be thermally isolated from any ignition source and flammable substances to prevent melting from an external fire. If the processor itself (or rags, etc.) inside this area ignited and did melt the tanks, the resulting fire (& spills, provided there is secondary containment) should be contained to that room.
The question to answer, particular to one's circumstance, is, would the cost of isolating/containing the plastic tanks cost as much as just buying metal tanks in the first place?

2) What is the risk of explosion in biodiesel processing, and does the processor need to be pressurized during the reaction?
Conclusion: There is always a risk of explosion with pressurized containers, especially those containing flammable materials, though exactly what that risk is in this case remains undefined. (Even if processing mistakes, faulty pressure-relief valves, and/or external fires never created enough pressure to cause an explosion, the potential exists for the rare error such as someone welding on a tank of raw glycerin.)
The last few posts on this thread seem to suggest that there is no reason to use a pressurized processor, if it is true that no methanol, and no heat, should escape during normal processing. I have not conducted the same experiment, but I did notice that no methanol collected in the long, coiled plastic tubes I installed months ago as vents on our processors (not even, it would seem, from the times during which methanol was added).
So, maybe I'm missing something obvious, but it seems to me that the safest way to go is non-pressurized metal tanks (for instance, with a loose-fitting, chained lid) with fully-contained plastic tanks a good cost-efficient second choice. No risk of explosion, no risk of uncontrollable fire, and - if Tilly is correct - no more methanol lost than from a pressurized tank. Unless there is some other reason to pressurize your tank...? (I don't think it makes the reaction go any faster; pressure shouldn't affect liquid reactions).

Some references, ramblings:
Methanol vapors are heavier than air under the same conditions, http://www.safety-council.org/info/OSH/methanol.htm - but - methanol evaporates when exposed to air, http://www.epa.gov/chemfact/f_methan.txt. (A good question is: how warm do methanol vapors have to be to be lighter than air?)
In a very large, non-pressurized container, some methanol fumes may dissipate outside the tank due to air currents around the tank; I think this explains why some industrial systems use foam to contain methanol fumes; but it seems that methanol fumes should not escape from a vessel with only a small vent like the Appleseed - without air currents, the fumes tend to just hover above the methanol. (Some industrial systems keep the space above liquids free of methanol fumes and oxygen - a potential hazard - by filling it with nitrogen).

One more:
Doesn't the potential for explosion exist even in a tank with a small vent or small pressure relief valve, if the source reaction happens faster than the pressure can escape... (say, a heater element blowing inside an air compressor - whose only relief now is through a small fitting to the plastic hose - sparking, & igniting a chamber of methanol fumes & oxygen)?

Pardon the length of this post - I just REALLY don't want to blow anything up, regardless of who's messing around my facility.

Greaseminer,

I don't know if this will help, but I chose to use large plastic cone bottom tanks. I process 200 gals. mixing for 1 hour and have passed the 27/3 almost every time.

I was not impressed with the Appleseed design for the volume that I need to do. (I think that the appleseeds are cool for what they are meant to do). This being said...

These are not pressure vessels, but they do seal well and hold enough above atmosphere to prevent methanol vapors from excaping at 130-140*F. I have a valved vent tube to the outside. I believe that the processor does need to be sealed, but not necessarily under pressure.

I have seen the photos and read the info on plastic tank faiures because of fire. I am a certified fire investigator, and the photos leave more questions than answers. Any container will melt without fluids. Just put an aluminium pan on a burner and allow the water to boil out, you will soon have a mass of melted metal. The fluid is the heat sink and prevents meltdown. Yes you will have more time (exposure to fire) before failure with a metal tank, but if the heat is that intense I think that you have already lost the fight.

Good housekeeping and good safe practices are the answers to prevent accidents.

Thanks for listening,

DGF

I might also suggest keeping a fire extinguisher around as well as setting up residential home sprinklers around your processing plant.

How to design a decent fire sprinkler system will be valuable.a bunch of 1" steel pipe with Tee's and the actuature? thingy screwed in!!!!!

Im gonna start a new thread. after a little search.

quote:

How to design a decent fire sprinkler system will be valuable.

The restaurant system is a sprinkler (in this case it was from a pressurized foam tank) over each unit (fryer, grill) with an actuator valve next to the exit. While running out and away from the fire, grab and yank the handle on your way by and it dumps the foam over the grill and fryer.

If you brew where it doesn't freeze, it wouldn't be hard to do something similar with a pressurized tank of water and a ball valve near the building exit.

I don't like the idea of counting on a heat-activated sprinkler head to open...what if it waits to long? Extra damage I could have avoided. What if it opens in appropriately (hot, sunny day...ceiling of a dark colored shed...)...I get a bath or a room full of sopping wet crap that I didn't have to have.

quote:

Originally posted by Hootep:
How to design a decent fire sprinkler system will be valuable.a bunch of 1" steel pipe with Tee's and the actuature? thingy screwed in!!!!!

Conventional fire-extinguishing sprinkler systems that use water as a medium are NOT ideal for grease (feedstock) fires. Keep this in mind in your research.

first off, there will be no fire if I am present. I have fire ext'rs and a hose , God willing. I cant imagine a single issue involving the process that would cause a "grease fire" (as long as I am present). Say I leave and there is a structural fire. That is what I want to prevent.
The fire dept will want a sprinkler system.

This is about the "what if", Im not here and somethng happens. Other than welding a tank full of meoh fumes Or a meoh mishap, I cant invision a grease fire. Unless its a structural fire and thats where the sprinkler system comes in.
No matter what, water will keep the temps low enough to prevent a grease/fuel fire.

Like I said before, hook up a pressurized tap water system with those sprinklers and your good? Where do you get them, how do they work?, maintenance? etc

quote:

Originally posted by Ryan P.:

quote:

How to design a decent fire sprinkler system will be valuable.

The restaurant system is a sprinkler (in this case it was from a pressurized foam tank) over each unit (fryer, grill) with an actuator valve next to the exit. While running out and away from the fire, grab and yank the handle on your way by and it dumps the foam over the grill and fryer.

If you brew where it doesn't freeze, it wouldn't be hard to do something similar with a pressurized tank of water and a ball valve near the building exit.

I don't like the idea of counting on a heat-activated sprinkler head to open...what if it waits to long? Extra damage I could have avoided. What if it opens in appropriately (hot, sunny day...ceiling of a dark colored shed...)...I get a bath or a room full of sopping wet crap that I didn't have to have.

Hot sunny inappropriately? come on these things are everywhere. every public building, not an issue. I have no idea about maitenance of them but I know companies service and certify them.

Having whatched many movies, it takes a minute or two with a lighter to set one off.

BTW, This is something anyone could potentialy do. Basement, shed, garage, commercial, etc.

quote:

Hot sunny inappropriately?

I worked construction at a GM assembly plant where it happened...I spent 12hrs sucking water on all 4 floors and as I was finishing the basement floor the heat had built up enough on the 4th floor to set them off again. Drag the 50gallon shop-vac back to floor 4 and start over...only took 6hrs to do it all the second time, though...less water.

NOW I should quantify that this wasn't sunshine setting them off. The paint baking ovens reach 400F and the plumbers had mistakenly installed all 250F sprinklers inside the ovens. On the first test firing of the new ovens, all sprinklers on the entire floor went off because they were also supply pressure sensitive; one goes, they all go.

So it CAN happen, under the right conditions...and most public buildings are climate controlled...most sheds are not.

How did we go from plastic vs. metal to fire supression systems?