## Vacuum Drying

Expand Messages
• Hello Everybody This question is directed towards anybody who might be able to help. If I had 1 gallon of water and I applied a vacuum high enough to boil it.
Message 1 of 19 , Sep 28, 2002
Hello Everybody

This question is directed towards anybody who might be able to help.

If I had 1 gallon of water and I applied a vacuum high enough to boil
it. How many Cubit / Feet, or Liters, of oxygen and hydrogen would it
produce when it was finally boiled dry.

A second question, would 30 inches of vacuum apply as much pull as 30
inches of pressure would apply push, on a piston of the same size? As I
see it the vacuum would only be applying a single atmosphere (14 PSI)
because it would only be removing a single atmosphere and the 30 PSI of
pressure would be applying a pound or two over 2 atmospheres. The reason
I ask is that I know where there is a 1000 gallon popane tank that was
damaged in a grass fire. It is no longer usuable as a popane tank but I
think it would make a great vacuum tank. With a few modifications to
get the malt and spent grains in and out.

Sorry for the abstract questions but any answer would be appreciated. I
would really hate to buy these tanks and then find out they are not
strong enough to hold a vacuum capable of evaporating the water in my
grains and malts.

George
• George Wessel wrote: Subject: [new_distillers] Vacuum Drying If I had 1 gallon of water and I applied a vacuum high enough to boil it. How many Cubit / Feet,
Message 2 of 19 , Sep 28, 2002
George Wessel wrote:
Subject: [new_distillers] Vacuum Drying
If I had 1 gallon of water and I applied a vacuum high enough to boil
it.  How many Cubit / Feet, or Liters, of oxygen and hydrogen would it
produce when it was finally boiled dry.
========================
Boiling does not split water up into oxygen and hydrogen.  For that you need electrolysis.
However, if you mean "what is the volume of water vapor given off by 1 gallon of water?" then that would be:
4,706 liters of vapor from 1 US gallon
5,652 liters of vapor from 1 Imperial gallon
========================
A second question,  would 30 inches of vacuum apply as much pull as 30
inches of pressure would apply push, on a piston of the same size?
========================
Yes, but you would never get 30 inches vacuum (I'm assuming you mean inches of mercury, like a barometer) as this is more than a perfect vacuum.
========================
As I see it the vacuum would only be applying a single atmosphere (14 PSI)
because it would only be removing a single atmosphere and the 30 PSI of
pressure would be applying a pound or two over 2 atmospheres. The reason
I ask is that I know where there is a 1000 gallon popane tank that was
damaged in a grass fire.  It is no longer usuable as a popane tank but I
think it would make a great vacuum tank.  With a few modifications to
get the malt and spent grains in and out.
========================
The propane tank will be designed to withstand pressure from within, and not from outside.
However, you would probably get away with it as these beasties are made to withstand all sorts of rough treatment.  Quickest test would be to chuck some water in and light a fire underneath to boil it. The steam will drive out all the air if you leave it long enough, then just seal the tank and remove the fire.  You'll get a great vacuum when the tank cools down, and if it crumples, don't buy it!
One other thing to bear in mind if you do go this way, is that you would still have to heat it to stop the water freezing.
========================
Sorry for the abstract questions but any answer would be appreciated. I
would really hate to buy these tanks and then find out they are not
strong enough to hold a vacuum capable of evaporating the water in my
grains and malts.
========================
No problem George.  Nothing is too good for a founder member of The Amphora Society!  :-))
I'll run this question past Mike McCaw as such processing is right up his street.  He may also be able you give you some ideas on easier methods.

All the best,
Mike Nixon
• Hi George, I have also a few remarks. Over here they add a VERY strong and awful smelling product to propane, so the propane (or butane) can be detected in
Message 3 of 19 , Sep 29, 2002
Hi George,

I have also a few remarks.

Over here they add a VERY strong and awful smelling product to
propane, so the propane (or butane) can be detected in case of leaks.
I have opened those propane tanks (I use them as supplementary tanks
for compressed air) and man... what a smell! I think it would ruin
whatever you put inside that tank for years. This product looks like
an oily substance and smells at least as strong as an essential oil.
I don't know what this product is, but I'll try to find it out. You
might be able to clean it out, but it's like this product becomes
soaked into the tank material itself.

Do you have a vacuum pump ? How much vacuum does it pull ? Do you
have freeze-drying in mind ?

Most vacuum pumps are not designed to draw water out. They work with
oil lubed vanes and make something like "mayonnaise" when sucking
water vapour. Some vacuum pumps are oil-less and these are better
suited for drying. With increasing vacuum (= also more expensive
pumps), the boiling point lowers. At what temperature would you like
to dry ? This determines the vacuum you'll need.

Freeze drying is the most sophisticated of vacuum drying and is a
marvellous invention, providing the highest quality and longtime
storage of the dried products, but is more complicated for the common
do-it-yourselver.

Greetings,
Dirk
• ... Thanks a bunch Mike I all ready have a vacuum pump. I brought a 2 cows milking machine at a sale for \$100 US. It came complete with a vacuum pump. It can
Message 4 of 19 , Sep 30, 2002
> The propane tank will be designed to withstand pressure from within, and
> not from outside.
>
> However, you would probably get away with it as these beasties are made
> to withstand all sorts of rough treatment. Quickest test would be
> to chuck some water in and light a fire underneath to boil it. The steam
> will drive out all the air if you leave it long enough, then just seal
> the tank and remove the fire. You'll get a great vacuum when the tank
> cools down, and if it crumples, don't buy it!

Thanks a bunch Mike

I all ready have a vacuum pump. I brought a 2 cows milking machine at a
sale for \$100 US. It came complete with a vacuum pump. It can pull a 20
- 21 pound vacuum on the guage. It is the damaged popane tanks that I
do not have. In order to run any tests I would have to buy the tanks.
This is why I have so many questions while a test would be so easy to do.

> One other thing to bear in mind if you do go this way, is that you
> would still have to heat it to stop the water freezing.

Would not the freezing point of water drop under a vacuum as well as the
boiling point?

If it makes any difference I am working on fuel grade alcohol. I figure
I should be able to dry my malted grain and my spent grains after
fermentation in these tanks. Vent the compressor exhaust from the malt
in the open and vent the exhaust from the spent grains into a condenser,
back to the wort storage tank. My worst fear now is that this might not
be a very fast process.

The worst I guess is that I will have to get two milk cows and drink
lots of milk.

Thanks again
George
• George Wessel wrote: Subject: Re: [new_distillers] Vacuum Drying Would not the freezing point of water drop under a vacuum as well as the boiling point?
Message 5 of 19 , Sep 30, 2002

George Wessel wrote:
Subject: Re: [new_distillers] Vacuum Drying

Would not the freezing point of water drop under a vacuum as well as the boiling point?
=============================
Nope.  Freezing is not the same as boiling.  Freezing occurs when molecular movement slows to such an extent that molecules can bind closely together in a solid, crystalline state.  Boiling occurs when the vapor pressure of the hot liquid is the same as the atmospheric pressure, so you can boil a liquid either by heating it up to increase its vapor pressure, or by lowering the atmospheric pressure to match the liquid's vapor pressure at whatever temperature it's at.

Boiling takes heat energy to turn the water into water vapor, and if you boil water by just lowering the pressure then this heat comes from the water itself.  This lowers its temperature of the water, and if you keep lowering the pressure so that it is always less than the vapor pressure of the water (the vapor pressure of water decreases as the temperature drops) then the water will keep boiling, but at lower and lower temperatures, and eventually freeze.  If you want to get rid of all the water by vacuum boiling, you therefore have to supply heat to keep the water liquid.

Frankly, I think that this is the hard way of doing what you want to do, and with no assurance of success.  As Dirk (homedistiller) pointed out, those propane tanks are likely to be heavily contaminated and would ruin your product.  He also points out that the other option of freeze drying, although great, is very complicated and, I imagine, very expensive to set up.  Mike McCaw has noted that the big boys in modern malting works use "through air" drying as it has proved to be efficient and cost effective.  At the risk of sounding defeatist, I would suggest you follow that advice.  As for the vacuum pump that came with your milking machine investment, I hope for the sake of the cows that it doesn't produce a vacuum strong enough to boil water!  You must have a lot of very unhappy cows in your area :-(

Mike Nixon

• ... Our popane stinks as well. I am not going for food quality. But for fuel grade alcohol. ... Yes I do have a small vacuum pump. It is an old 2 cow Surge
Message 6 of 19 , Sep 30, 2002
"homedistiller" <homedistiller@...> wrote:

>Hi George,
>
>I have also a few remarks.
>
>Over here they add a VERY strong and awful smelling product to
>propane, so the propane (or butane) can be detected in case of leaks.
>I have opened those propane tanks (I use them as supplementary tanks
>for compressed air) and man... what a smell! I think it would ruin
>whatever you put inside that tank for years. This product looks like
>an oily substance and smells at least as strong as an essential oil.
>I don't know what this product is, but I'll try to find it out. You
>might be able to clean it out, but it's like this product becomes
>soaked into the tank material itself.

Our popane stinks as well. I am not going for food quality. But for fuel grade alcohol.

>Do you have a vacuum pump ? How much vacuum does it pull ? Do you
>have freeze-drying in mind ?

Yes I do have a small vacuum pump. It is an old 2 cow Surge piston type and freeze drying is exactly what I am going after. I plugged up the outbound lines and attached a guage and got 20 to 21 inches.

>
>Most vacuum pumps are not designed to draw water out. They work with
>oil lubed vanes and make something like "mayonnaise" when sucking
>water vapour. Some vacuum pumps are oil-less and these are better
>suited for drying. With increasing vacuum (= also more expensive
>pumps), the boiling point lowers. At what temperature would you like
>to dry ? This determines the vacuum you'll need.

At 20 inches of vacuum, how cold would become to cold?

>
>Freeze drying is the most sophisticated of vacuum drying and is a
>marvellous invention, providing the highest quality and longtime
>storage of the dried products, but is more complicated for the common
>do-it-yourselver.

Is there any special technique required? I was just going to pull it down to all my pump had and shut the value and pull it down again when the vacuum got a little low. Experience I figured would tell me how long to hold the vacuum for whatever I was drying.

George

>Greetings,
>Dirk
>
>
>

__________________________________________________________________

Get your own FREE, personal Netscape Mail account today at http://webmail.netscape.com/
• Aha!!!! Well that certainly answers that question George, but raises another: why do you want to dry the grain when it is the sugars you want from the
Message 7 of 19 , Sep 30, 2002
Aha!!!!   Well that certainly answers that question George, but raises another:  why do you want to dry the grain when it is the sugars you want from the malted grain to ferment in order to make your fuel alcohol?  Am I missing something?  Also, a useful byproduct from grain produced alcohol is the spent grain, which can be sold as fodder.  Not sure that your two cows would appreciate the smell of it though after its been through that propane tank.

Mike N
----- Original Message -----
Sent: Tuesday, October 01, 2002 11:56 AM
Subject: RE: [new_distillers] Re: Vacuum Drying

"homedistiller" <homedistiller@...> wrote:

>Hi George,
>
>I have also a few remarks.
>
>Over here they add a VERY strong and awful smelling product to
>propane, so the propane (or butane) can be detected in case of leaks.
>I have opened those propane tanks (I use them as supplementary tanks
>for compressed air) and man... what a smell! I think it would ruin
>whatever you put inside that tank for years. This product looks like
>an oily substance and smells at least as strong as an essential oil.
>I don't know what this product is, but I'll try to find it out. You
>might be able to clean it out, but it's like this product becomes
>soaked into the tank material itself.

Our popane stinks as well.  I am not going for food quality.  But for fuel grade alcohol.

>Do you have a vacuum pump ? How much vacuum does it pull ? Do you
>have freeze-drying in mind ?

Yes I do have a small vacuum pump.  It is an old 2 cow Surge piston type and freeze drying is exactly what I am going after.  I plugged up the outbound lines and attached a guage and got 20 to 21 inches.

>
>Most vacuum pumps are not designed to draw water out. They work with
>oil lubed vanes and make something like "mayonnaise" when sucking
>water vapour. Some vacuum pumps are oil-less and these are better
>suited for drying. With increasing vacuum (= also more expensive
>pumps), the boiling point lowers. At what temperature would you like
>to dry ? This determines the vacuum you'll need.

At 20 inches of vacuum, how cold would become to cold?

>
>Freeze drying is the most sophisticated of vacuum drying and is a
>marvellous invention, providing the highest quality and longtime
>storage of the dried products, but is more complicated for the common
>do-it-yourselver.

Is there any special technique required?  I was just going to pull it down to all my pump had and shut the value and pull it down again when the vacuum got a little low.  Experience I figured would tell me how long to hold the vacuum for whatever I was drying.

George

>Greetings,
>Dirk
>
>
>

__________________________________________________________________

Get your own FREE, personal Netscape Mail account today at http://webmail.netscape.com/

To unsubscribe from this group, send an email to:
new_distillers-unsubscribe@onelist.com

• there was a discussion along these lines in the bio fuel list about 3 or 4 months ago. MotieD was trying to find a way to start the distillation process using
Message 8 of 19 , Sep 30, 2002
there was a discussion along these lines in the bio fuel list about 3
or 4 months ago. MotieD was trying to find a way to start the
distillation process using vacuum and a lower boiling temperature.
He was trying to reduce the energy consumption in the distillation
phase.

One of the suggestions was to use a large propane tank as a
vacuum 'engine' or storeage device. Much like a capacitor in
electronics work. They discussed that because a 2 thousand gallon
propane tank at 30 inches of vacuum would have such a large volume it
could be used to store the vacuum and then draw the ethanol vapor
into it during a low temperature distillation.

after the distillation phase, the tank can be emptied.

In the fuels lists, 'drying' is the term they are using (right or
wrong) when they are attempting to get as close to anhydrous ethanol
as possible.

--- In new_distillers@y..., "Mike Nixon" <mike@s...> wrote:
> Aha!!!! Well that certainly answers that question George, but
raises another: why do you want to dry the grain when it is the
sugars you want from the malted grain to ferment in order to make
your fuel alcohol? Am I missing something? Also, a useful byproduct
from grain produced alcohol is the spent grain, which can be sold as
fodder. Not sure that your two cows would appreciate the smell of it
though after its been through that propane tank.
>
> Mike N
> ----- Original Message -----
> From: georgelola@n...
> To: new_distillers@y...
> Sent: Tuesday, October 01, 2002 11:56 AM
> Subject: RE: [new_distillers] Re: Vacuum Drying
>
>
> "homedistiller" <homedistiller@y...> wrote:
>
> >Hi George,
> >
> >I have also a few remarks.
> >
> >Over here they add a VERY strong and awful smelling product to
> >propane, so the propane (or butane) can be detected in case of
leaks.
> >I have opened those propane tanks (I use them as supplementary
tanks
> >for compressed air) and man... what a smell! I think it would
ruin
> >whatever you put inside that tank for years. This product looks
like
> >an oily substance and smells at least as strong as an essential
oil.
> >I don't know what this product is, but I'll try to find it out.
You
> >might be able to clean it out, but it's like this product
becomes
> >soaked into the tank material itself.
>
> Our popane stinks as well. I am not going for food quality. But
>
>
>
>
>
> >Do you have a vacuum pump ? How much vacuum does it pull ? Do you
> >have freeze-drying in mind ?
>
> Yes I do have a small vacuum pump. It is an old 2 cow Surge
piston type and freeze drying is exactly what I am going after. I
plugged up the outbound lines and attached a guage and got 20 to 21
inches.
>
>
>
>
>
>
>
> >
> >Most vacuum pumps are not designed to draw water out. They work
with
> >oil lubed vanes and make something like "mayonnaise" when sucking
> >water vapour. Some vacuum pumps are oil-less and these are
better
> >suited for drying. With increasing vacuum (= also more expensive
> >pumps), the boiling point lowers. At what temperature would you
like
> >to dry ? This determines the vacuum you'll need.
>
> At 20 inches of vacuum, how cold would become to cold?
>
>
> >
> >Freeze drying is the most sophisticated of vacuum drying and is
a
> >marvellous invention, providing the highest quality and longtime
> >storage of the dried products, but is more complicated for the
common
> >do-it-yourselver.
>
> Is there any special technique required? I was just going to
pull it down to all my pump had and shut the value and pull it down
again when the vacuum got a little low. Experience I figured would
tell me how long to hold the vacuum for whatever I was drying.
>
> George
>
>
> >Greetings,
> >Dirk
> >
> >
> >
>
> __________________________________________________________________
> The NEW Netscape 7.0 browser is now available. Upgrade now!
>
> Get your own FREE, personal Netscape Mail account today at
http://webmail.netscape.com/
>
>
>
>
>
> To unsubscribe from this group, send an email to:
> new_distillers-unsubscribe@o...
>
>
>
> Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.
• ... From: CornFed (Randy) To: new_distillers@yahoogroups.com Sent: Tuesday, October 01, 2002 3:36 PM Subject: [new_distillers] Re: Vacuum Drying there was a
Message 9 of 19 , Sep 30, 2002
----- Original Message -----
From: CornFed (Randy)
To: new_distillers@yahoogroups.com
Sent: Tuesday, October 01, 2002 3:36 PM
Subject: [new_distillers] Re: Vacuum Drying

there was a discussion along these lines in the bio fuel list about 3
or 4 months ago. MotieD was trying to find a way to start the
distillation process using vacuum and a lower boiling temperature.
He was trying to reduce the energy consumption in the distillation
phase.

One of the suggestions was to use a large propane tank as a
vacuum 'engine' or storeage device. Much like a capacitor in
electronics work. They discussed that because a 2 thousand gallon
propane tank at 30 inches of vacuum would have such a large volume it
could be used to store the vacuum and then draw the ethanol vapor
into it during a low temperature distillation.

after the distillation phase, the tank can be emptied.

In the fuels lists, 'drying' is the term they are using (right or
wrong) when they are attempting to get as close to anhydrous ethanol
as possible.
========================
Thanks Randy. I've just been doing some figgerin ... a 2000 US gallon
propane tank exhausted to 30 inches vacuum would be subjected to a pressure
of 235.3 tons! I just love trivia like that :-))

Mike N
• Ethanol is a superior parts cleaning solvent. after a few large runs of ethanol throught it the smell should be close to being cleaned out. Your car wont
Message 10 of 19 , Sep 30, 2002
Ethanol is a superior parts cleaning solvent. after a few large
runs of ethanol throught it the smell should be close to being
cleaned out. Your car wont notice a bit.

--- In new_distillers@y..., georgelola@n... wrote:
> "homedistiller" <homedistiller@y...> wrote:
>
> >Hi George,
> >
> >I have also a few remarks.
> >
> >Over here they add a VERY strong and awful smelling product to
> >propane, so the propane (or butane) can be detected in case of
leaks.
> >I have opened those propane tanks (I use them as supplementary
tanks
> >for compressed air) and man... what a smell! I think it would ruin
> >whatever you put inside that tank for years. This product looks
like
> >an oily substance and smells at least as strong as an essential
oil.
> >I don't know what this product is, but I'll try to find it out. You
> >might be able to clean it out, but it's like this product becomes
> >soaked into the tank material itself.
>
> Our popane stinks as well. I am not going for food quality. But
>
>
>
>
>
> >Do you have a vacuum pump ? How much vacuum does it pull ? Do you
> >have freeze-drying in mind ?
>
> Yes I do have a small vacuum pump. It is an old 2 cow Surge piston
type and freeze drying is exactly what I am going after. I plugged
up the outbound lines and attached a guage and got 20 to 21 inches.
>
>
>
>
>
>
>
> >
> >Most vacuum pumps are not designed to draw water out. They work
with
> >oil lubed vanes and make something like "mayonnaise" when sucking
> >water vapour. Some vacuum pumps are oil-less and these are better
> >suited for drying. With increasing vacuum (= also more expensive
> >pumps), the boiling point lowers. At what temperature would you
like
> >to dry ? This determines the vacuum you'll need.
>
> At 20 inches of vacuum, how cold would become to cold?
>
>
> >
> >Freeze drying is the most sophisticated of vacuum drying and is a
> >marvellous invention, providing the highest quality and longtime
> >storage of the dried products, but is more complicated for the
common
> >do-it-yourselver.
>
> Is there any special technique required? I was just going to pull
it down to all my pump had and shut the value and pull it down again
when the vacuum got a little low. Experience I figured would tell me
how long to hold the vacuum for whatever I was drying.
>
> George
>
>
> >Greetings,
> >Dirk
> >
> >
> >
>
> __________________________________________________________________
> The NEW Netscape 7.0 browser is now available. Upgrade now!
>
> Get your own FREE, personal Netscape Mail account today at
http://webmail.netscape.com/
• ok then start at a lower vacuum level. The point was to have the stored capacity to draw the contents in to the tank while using less heat energy to get it
Message 11 of 19 , Sep 30, 2002
ok then start at a lower vacuum level. The point was to have the
stored capacity to draw the contents in to the tank while using less
heat energy to get it into vapor form. 30 inches will boil water at
room temperature.

the point of using the tank was that finding a vacuum pump large
enough to service the distillation would be very costly and out of
the home hobbiest range. Also there was discussion about the heat
and the ethanol vapor destroying the pump in the process. Using the
tank as a storeage vessel would allow you to draw it down ahead of
time and use it as a stored energy source.

30 inches of vacuum was the number that we worked with when doing air
conditioning repairs. "draw down to 30 inches for 30 minutes with
the pump and then held for an hour with valves closed" ensured at
moisture was removed and that there wasnt any leaks. got to love
that trivia.

> ========================
> Thanks Randy. I've just been doing some figgerin ... a 2000 US
gallon
> propane tank exhausted to 30 inches vacuum would be subjected to a
pressure
> of 235.3 tons! I just love trivia like that :-))
>
> Mike N
• Hello George, I m still somewhat puzzled about what you want to dry actually. In the beginning, I (and others) thought you wanted to dry the spent grains. But
Message 12 of 19 , Oct 1, 2002
Hello George,

I'm still somewhat puzzled about what you want to dry actually.

In the beginning, I (and others) thought you wanted to dry the spent
grains.

But now, after all the postings on the subject, I also start to think
that you want to "dry" the ethanol. Am I right, or are you thinking
about distilling under vacuum as well ?

With vacuum distilling, one could catch two birds in one shot:
distilling at low temperatures AND obtaining 100% pure ethanol,
because
the azeotrope disappears from a certain vacuum. Sadly, I have no
experience on this matter, but I'm interested.
See for more:
http://homedistiller.org/designs.htm#vacuum

Freeze-drying ethanol to remove the remaining percentages water from
ethanol doesn't exist. It's the technology used to preserve foods,
flowers etc. First, the items are frozen solid, then such a vacuum is
applied, that the frozen water inside the items turns into vapour,
without becoming liquid. This is a very slow process.

I think the best way for the amateur to dry ethanol are molecular
sieves. See for more:
http://homedistiller.org/polish.htm#dry

But then again: do you need 100% pure ? I believe this is only needed
when you want to mix the ethanol with other fuels.
I read that most gasoline cars drive fine on 85% (or better) ethanol.
It's only when you mix with other fuels that the water separates out.

Greetings,
Dirk
• Hi Randy, This buffer-idea sounds terrific! Did some people try this setup already ? I use a similar principle for compressed air: two ex-propane tanks of
Message 13 of 19 , Oct 1, 2002
Hi Randy,

This buffer-idea sounds terrific!

Did some people try this setup already ?

I use a "similar" principle for compressed air: two ex-propane tanks
of 1600 liters each. When these are filled, I not only go a long way,
but I can also run tools that a small compressor wouldn't handle.

Could this vacuum buffer solve it all ?

Would a bigger buffertank eliminate the need for a vacuumpump during
distillation ?

In a sense it should, we don't want to remove anything out of a
closed system, we just want to separate.

Then indeed:
1) Make a closed-circuit batch-distillation set-up that can be sealed-
off hermetically.
2) Apply the desired vacuum to the system.
3) Seal-off the system.
4) Apply heat input
5) The wash boils at a low temperature (depending the vacuum value)
6) Everything should be done as with "normal" distilling but now at
lower or much lower temperatures, again depending the existing vacuum.

The buffer/cooler/recipient-tank could be placed in a cool (cold or
very cold) area. A precooler for the distillate could be used.

Is that really all ? Is it too good to be true ?

Am I making a fatal mistake somewhere in the thinking ?

Not too sure about vapour pressure and how this will try to ruin our
desired vacuum.

Just thinking out loud.

Sincerely,
Dirk

--- In new_distillers@y..., "CornFed (Randy)" <cornfed15@h...> wrote:
> there was a discussion along these lines in the bio fuel list about
3
> or 4 months ago. MotieD was trying to find a way to start the
> distillation process using vacuum and a lower boiling temperature.
> He was trying to reduce the energy consumption in the distillation
> phase.
>
> One of the suggestions was to use a large propane tank as a
> vacuum 'engine' or storeage device. Much like a capacitor in
> electronics work. They discussed that because a 2 thousand gallon
> propane tank at 30 inches of vacuum would have such a large volume
it
> could be used to store the vacuum and then draw the ethanol vapor
> into it during a low temperature distillation.
>
> after the distillation phase, the tank can be emptied.
>
• Randy, I ve seen a small (50 liter, diameter 30 cm) propane tank used as a vacuum tank (95% vacuum). Bigger sized tanks used for vacuum buffer are definitely
Message 14 of 19 , Oct 1, 2002
Randy,

I've seen a small (50 liter, diameter 30 cm) propane tank used as a
vacuum tank (95% vacuum).

Bigger sized tanks used for vacuum buffer are definitely heavier
constructed than regular pressure tanks. They have thicker walls and
have circular reinforcing ribs.

Look at those carbonated drink cans or those plastic PET-bottles.
They handle very well high internal pressures but crumble under a
relatively small external overpressure.

I think that using bigger propane tanks for vacuum is possible, but
would require adding external framing, to avoid collapsing at higher
vacuum.

Sincerely,
Dirk

--- In new_distillers@y..., "CornFed (Randy)" <cornfed15@h...> wrote:
> ok then start at a lower vacuum level. The point was to have the
> stored capacity to draw the contents in to the tank while using
less
> heat energy to get it into vapor form. 30 inches will boil water
at
> room temperature.
>
> the point of using the tank was that finding a vacuum pump large
> enough to service the distillation would be very costly and out of
> the home hobbiest range. Also there was discussion about the heat
> and the ethanol vapor destroying the pump in the process. Using
the
> tank as a storeage vessel would allow you to draw it down ahead of
> time and use it as a stored energy source.
>
> 30 inches of vacuum was the number that we worked with when doing
air
> conditioning repairs. "draw down to 30 inches for 30 minutes with
> the pump and then held for an hour with valves closed" ensured at
> moisture was removed and that there wasnt any leaks. got to love
> that trivia.
>
>
> > ========================
> > Thanks Randy. I've just been doing some figgerin ... a 2000 US
> gallon
> > propane tank exhausted to 30 inches vacuum would be subjected to
a
> pressure
> > of 235.3 tons! I just love trivia like that :-))
> >
> > Mike N
• as far as I know it was just a concept that was kicked around for a while. I believe they ran into a roadblock determining just how to go about the vacuum
Message 15 of 19 , Oct 1, 2002
as far as I know it was just a concept that was kicked around for a
while. I believe they ran into a roadblock determining just how to
go about the vacuum distillation phase.

then the conversation dropped from the list and I havent heard about
it since til now. On a totally differnt list.

--- In new_distillers@y..., "homedistiller" <homedistiller@y...>
wrote:
> Hi Randy,
>
> This buffer-idea sounds terrific!
>
> Did some people try this setup already ?
>
> I use a "similar" principle for compressed air: two ex-propane tanks
> of 1600 liters each. When these are filled, I not only go a long
way,
> but I can also run tools that a small compressor wouldn't handle.
>
> Could this vacuum buffer solve it all ?
>
> Would a bigger buffertank eliminate the need for a vacuumpump
during
> distillation ?
>
> In a sense it should, we don't want to remove anything out of a
> closed system, we just want to separate.
>
> Then indeed:
> 1) Make a closed-circuit batch-distillation set-up that can be
sealed-
> off hermetically.
> 2) Apply the desired vacuum to the system.
> 3) Seal-off the system.
> 4) Apply heat input
> 5) The wash boils at a low temperature (depending the vacuum value)
> 6) Everything should be done as with "normal" distilling but now at
> lower or much lower temperatures, again depending the existing
vacuum.
>
> The buffer/cooler/recipient-tank could be placed in a cool (cold or
> very cold) area. A precooler for the distillate could be used.
>
> Is that really all ? Is it too good to be true ?
>
> Am I making a fatal mistake somewhere in the thinking ?
>
> Not too sure about vapour pressure and how this will try to ruin
our
> desired vacuum.
>
> Just thinking out loud.
>
> Sincerely,
> Dirk
>
>
>
>
> --- In new_distillers@y..., "CornFed (Randy)" <cornfed15@h...>
wrote:
> > there was a discussion along these lines in the bio fuel list
> 3
> > or 4 months ago. MotieD was trying to find a way to start the
> > distillation process using vacuum and a lower boiling
temperature.
> > He was trying to reduce the energy consumption in the
distillation
> > phase.
> >
> > One of the suggestions was to use a large propane tank as a
> > vacuum 'engine' or storeage device. Much like a capacitor in
> > electronics work. They discussed that because a 2 thousand
gallon
> > propane tank at 30 inches of vacuum would have such a large volume
> it
> > could be used to store the vacuum and then draw the ethanol vapor
> > into it during a low temperature distillation.
> >
> > after the distillation phase, the tank can be emptied.
> >
• ... (snip) This is along the same lines as I am thinking Thanks ... (snip) Does a popane tank make as big a bang when it implodes as it does when it explodes?
Message 16 of 19 , Oct 1, 2002
>
>
> there was a discussion along these lines in the bio fuel list about 3
> or 4 months ago. MotieD was trying to find a way to start the
> distillation process using vacuum and a lower boiling temperature.
> He was trying to reduce the energy consumption in the distillation
> phase.
>
> One of the suggestions was to use a large propane tank as a
> vacuum 'engine' or storeage device. Much like a capacitor in
> electronics work. They discussed that because a 2 thousand gallon
> propane tank at 30 inches of vacuum would have such a large volume it
> could be used to store the vacuum and then draw the ethanol vapor
> into it during a low temperature distillation.
>
> after the distillation phase, the tank can be emptied.

(snip)
This is along the same lines as I am thinking

Thanks

>
> ========================
> Thanks Randy. I've just been doing some figgerin ... a 2000 US gallon
> propane tank exhausted to 30 inches vacuum would be subjected to a pressure
> of 235.3 tons! I just love trivia like that :-))
>

(snip)
Does a popane tank make as big a bang when it implodes as it does when
it explodes? Just wondering how far back I should dig my hole to hid
in. Or how far out into the pasture I need to drag this thing before I
apply the vacuum.

Looks like I'll just have to front the \$50.00 bucks and hook up a vacuum
pump and wait and see.
• ... This and my freshly grown malted barley is all. I explained farther in another email. Thanks
Message 17 of 19 , Oct 1, 2002
homedistiller@... wrote:

> Hello George,
>
> I'm still somewhat puzzled about what you want to dry actually.
>
> In the beginning, I (and others) thought you wanted to dry the spent
> grains.
>

This and my freshly grown malted barley is all. I explained farther in
another email.

Thanks
• Hi All! Glad to see this topic again. Randy informed me off-list about it. I ve been gone for several months, and only able to check my Emails irregularly. My
Message 18 of 19 , Oct 2, 2002
Hi All!
Glad to see this topic again. Randy informed me off-list about it.
I've been gone for several months, and only able to check my Emails
irregularly.
My original premise was not simply to do a vacuum distilation, but
to do a vacuum fermentation concurrently. I wanted to distill off at
least some of the Ethanol at a temp where the Yeasts could survive
and keep working to keep the mash below 10%.
Sort of a crude continous-process. Keep adding sugar and drawing off
Ethanol with a vacuum.
It will be another month or so before I have much time to actively
participate.

Keep thinking!
Motie

--- In new_distillers@y..., "CornFed (Randy)" <cornfed15@h...> wrote:
> as far as I know it was just a concept that was kicked around for a
> while. I believe they ran into a roadblock determining just how to
> go about the vacuum distillation phase.
>
> then the conversation dropped from the list and I havent heard
> it since til now. On a totally differnt list.
>
>
> --- In new_distillers@y..., "homedistiller" <homedistiller@y...>
> wrote:
> > Hi Randy,
> >
> > This buffer-idea sounds terrific!
> >
> > Did some people try this setup already ?
> >
> > I use a "similar" principle for compressed air: two ex-propane
tanks
> > of 1600 liters each. When these are filled, I not only go a long
> way,
> > but I can also run tools that a small compressor wouldn't handle.
> >
> > Could this vacuum buffer solve it all ?
> >
> > Would a bigger buffertank eliminate the need for a vacuumpump
> during
> > distillation ?
> >
> > In a sense it should, we don't want to remove anything out of a
> > closed system, we just want to separate.
> >
> > Then indeed:
> > 1) Make a closed-circuit batch-distillation set-up that can be
> sealed-
> > off hermetically.
> > 2) Apply the desired vacuum to the system.
> > 3) Seal-off the system.
> > 4) Apply heat input
> > 5) The wash boils at a low temperature (depending the vacuum
value)
> > 6) Everything should be done as with "normal" distilling but now
at
> > lower or much lower temperatures, again depending the existing
> vacuum.
> >
> > The buffer/cooler/recipient-tank could be placed in a cool (cold
or
> > very cold) area. A precooler for the distillate could be used.
> >
> > Is that really all ? Is it too good to be true ?
> >
> > Am I making a fatal mistake somewhere in the thinking ?
> >
> > Not too sure about vapour pressure and how this will try to ruin
> our
> > desired vacuum.
> >
> > Just thinking out loud.
> >
> > Sincerely,
> > Dirk
> >
> >
> >
> >
> > --- In new_distillers@y..., "CornFed (Randy)" <cornfed15@h...>
> wrote:
> > > there was a discussion along these lines in the bio fuel list
> > 3
> > > or 4 months ago. MotieD was trying to find a way to start the
> > > distillation process using vacuum and a lower boiling
> temperature.
> > > He was trying to reduce the energy consumption in the
> distillation
> > > phase.
> > >
> > > One of the suggestions was to use a large propane tank as a
> > > vacuum 'engine' or storeage device. Much like a capacitor in
> > > electronics work. They discussed that because a 2 thousand
> gallon
> > > propane tank at 30 inches of vacuum would have such a large
volume
> > it
> > > could be used to store the vacuum and then draw the ethanol
vapor
> > > into it during a low temperature distillation.
> > >
> > > after the distillation phase, the tank can be emptied.
> > >
• raises another: why do you want to dry the grain when it is the sugars you want from the malted grain to ferment in order to make your fuel alcohol? Am I
Message 19 of 19 , Oct 2, 2002
raises another: why do you want to dry the grain when it is the
sugars you want from the malted grain to ferment in order to make
your fuel alcohol? Am I missing something?

(snip)
I want to dry the spent grains after I ferment it. First of all to get
all the recoverable alcohol out of the grain and second so it will store
until it can be fed. Last of all because you can only feed a cow so
much water per day in her daily diet. I will have to look it up, I'm not
sure anymore how much it was but it can be easily surpassed when feeding
spent grains. One place I saw piped their CO2 from their fermenter into
a box that held their spend grains and they fed out of the box. No
oxygen or less oxygen, no spoilage.

Not sure that your two cows would appreciate the smell of it
though after its been through that propane tank.

(snip)
I would have to be inclined to say that after I heat these tanks a few
times the popane smell would come out of the steel. Let me the first to
say I could be wrong. But I have smelled old popane tanks that have lost
this bad smell after setting awhile.
Your message has been successfully submitted and would be delivered to recipients shortly.