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Old 05-03-2004, 04:31 AM
Morten
 
Posts: n/a
Default DIY CO2 system question (Correct calculations)

Folks,

The calculations I did in the previous mail were wrong, I just double
checked them...

Here are the original mail with the right figures...

/Morten


---

The addition of baking soda (2NaHCO3) will not lower the amount of alcohol
(CH3CH2OH) on the solution unless you put so much if in there that it lovers
the pH too much below 5 effectually killing the yeast before it gets a
chance to convert the sugar (C6H12O6) to CO2

The chemical reaction (or at least the end result of the yeast's reduction
of sugar goes like this:

C6H12O6(aq) = 2(CH3CH2OH(aq)) + 2(CO2(g)) + energy (used by yeast)

so, for each mol of sugar you get 2 mol of CO2 and because the molar weight
of sugar is 180.1572 g/mol and the molar weight of CO2 is 44.0098 g/mol, you
will get (2 * 44.0098 g/mol) / 180.1572 g/mol = 0.4886 g CO2 for each g og
sugar.

This is max you can get but because some of the CO2 will stay in the water
in the yeast reactor you will get a little less than the 0.4886 g CO2 / g
sugar mentioned above.


Since the molar weight for alcohol (CH3CH2OH) is 46.0688 g/mol you will get
(2 * 46.0688 g/mol) / (180.1572 g/mol) = 0.5114 g alcohol for each g sugar
added to the reactor.


But, because the alcohol will kill the yeast if the concentration gets to
high (depending on which type of yeast is used, common baking yeast will
start to die arround (7% - 8%) we need to make sure that the concentration
of alcohol is low enough to make sure that all the sugar is consumed before
the alcohol kills the yeast.


If using 2.0L of water (H2O) = 2000g and 220g og sugar the end concentration
will be (0.4886 * 220 g ) / (2000 g + 04886 * 220 g) = 0.0533 = 5.33 % which
will alow the yeast to consume all the sugar and still survive the alcohol.

Using 220 g of sugar this will yield 0.5114 * 220g = 112.5143 g alcohol and
0.4886 * 220g = 107.4856 g CO2


When all the sugar is gone the yeast will 'floculate' out of solution and
sink to the bottom of the yeast container but will not die, so we can actual
ly re-use the yeast every time we set up another batch of sugar if we
carefully drains the water / alcohol solution from the container and don't
rinse the container with very hot water killing the yeast in the process.

In the long run it will benefit the yeast if we used a yeast nutrient (can
be bought from home brewers shops) to feed the yeast the nutrients that the
yeast needs to stay healthy for prolonged use.


Because some of the CO2 stays in the water we have a buffer solution like
this:

CO2 + H2O = H+(aq) + HCO3-(aq)

This process is dependent on temperature and the specific wapor pressure of
CO2 in the container and the water, but i can't remember how to calculate
the exact ammount of CO2 in solition given the pressure / temperature of the
solution, so I'll ignore this bit :-)

When adding baking soda you effectively increases the kH of the solution
which loveres the pH making the environment a little more hostile to the
yeast. If i remember correctly yeast prefers a pH of 5 to 6, but will
survive 4 to 9, so there are some room for pH swings before the yeast gives
up.

This reaction goes like this:

2NaHCO3 + H2O = 2Na+(aq) + 2HCO3-(aq)


Baking soda can be added to stabilise the pH in the reactor if the water
used have a very lov Kh, but for normal (higher that 4 Kh) water baking soda
actually makes the conditions for the yeast worse but might prolong the
reaction somewhat purely because some of the yeast will die because of the
higner pH in the reactor.



I hope this came through as i thought it, if not please dont hesitate to ask
further questions :-)


Regards

Morten
----



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  #2   Report Post  
Old 05-03-2004, 04:31 AM
Ken Pinard
 
Posts: n/a
Default DIY CO2 system question (Correct calculations)

Hi nice explanation, I do have a couple of questions. Mostly for my own
curious mind.

Since Baking Soda is Basic will it not raise the pH? I know we used it in
chemistry to neutralize the acids (even the stuff I dropped all of the
floor, what a mess ;o)

But since Baking Soda raises the kH, the amount of CO2 that is held in the
water solution will be higher. Thus creating carbonic acid. Which will lower
the pH.

I wish I remembered my chemistry better, its been 25 years now, I actually
find all these equations fascinating.

As I ponder the effect of alcohol on yeast, while I drink a little wine, I
am wondering what additive can combine with alcohol that will not kill the
yeast or react with CO2? I imagine that the idea has been explored before.
I just was curious.

Thank you for the explanation and equations, I am going to go over them with
my old chem books (still got them) and try and get them in my head again.

Ken Pinard (French meaning wine - I have alcohol on the brain


"Morten" wrote in message
...
Folks,

The calculations I did in the previous mail were wrong, I just double
checked them...

Here are the original mail with the right figures...

/Morten


---

The addition of baking soda (2NaHCO3) will not lower the amount of alcohol
(CH3CH2OH) on the solution unless you put so much if in there that it

lovers
the pH too much below 5 effectually killing the yeast before it gets a
chance to convert the sugar (C6H12O6) to CO2

The chemical reaction (or at least the end result of the yeast's reduction
of sugar goes like this:

C6H12O6(aq) = 2(CH3CH2OH(aq)) + 2(CO2(g)) + energy (used by yeast)

so, for each mol of sugar you get 2 mol of CO2 and because the molar

weight
of sugar is 180.1572 g/mol and the molar weight of CO2 is 44.0098 g/mol,

you
will get (2 * 44.0098 g/mol) / 180.1572 g/mol = 0.4886 g CO2 for each g og
sugar.

This is max you can get but because some of the CO2 will stay in the water
in the yeast reactor you will get a little less than the 0.4886 g CO2 / g
sugar mentioned above.


Since the molar weight for alcohol (CH3CH2OH) is 46.0688 g/mol you will

get
(2 * 46.0688 g/mol) / (180.1572 g/mol) = 0.5114 g alcohol for each g sugar
added to the reactor.


But, because the alcohol will kill the yeast if the concentration gets to
high (depending on which type of yeast is used, common baking yeast will
start to die arround (7% - 8%) we need to make sure that the concentration
of alcohol is low enough to make sure that all the sugar is consumed

before
the alcohol kills the yeast.


If using 2.0L of water (H2O) = 2000g and 220g og sugar the end

concentration
will be (0.4886 * 220 g ) / (2000 g + 04886 * 220 g) = 0.0533 = 5.33 %

which
will alow the yeast to consume all the sugar and still survive the

alcohol.

Using 220 g of sugar this will yield 0.5114 * 220g = 112.5143 g alcohol

and
0.4886 * 220g = 107.4856 g CO2


When all the sugar is gone the yeast will 'floculate' out of solution and
sink to the bottom of the yeast container but will not die, so we can

actual
ly re-use the yeast every time we set up another batch of sugar if we
carefully drains the water / alcohol solution from the container and don't
rinse the container with very hot water killing the yeast in the process.

In the long run it will benefit the yeast if we used a yeast nutrient (can
be bought from home brewers shops) to feed the yeast the nutrients that

the
yeast needs to stay healthy for prolonged use.


Because some of the CO2 stays in the water we have a buffer solution like
this:

CO2 + H2O = H+(aq) + HCO3-(aq)

This process is dependent on temperature and the specific wapor pressure

of
CO2 in the container and the water, but i can't remember how to calculate
the exact ammount of CO2 in solition given the pressure / temperature of

the
solution, so I'll ignore this bit :-)

When adding baking soda you effectively increases the kH of the solution
which loveres the pH making the environment a little more hostile to the
yeast. If i remember correctly yeast prefers a pH of 5 to 6, but will
survive 4 to 9, so there are some room for pH swings before the yeast

gives
up.

This reaction goes like this:

2NaHCO3 + H2O = 2Na+(aq) + 2HCO3-(aq)


Baking soda can be added to stabilise the pH in the reactor if the water
used have a very lov Kh, but for normal (higher that 4 Kh) water baking

soda
actually makes the conditions for the yeast worse but might prolong the
reaction somewhat purely because some of the yeast will die because of the
higner pH in the reactor.



I hope this came through as i thought it, if not please dont hesitate to

ask
further questions :-)


Regards

Morten
----



---
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  #3   Report Post  
Old 05-03-2004, 04:32 AM
Ken Pinard
 
Posts: n/a
Default DIY CO2 system question (Correct calculations)

Ok, now I am getting even more curious,

Do you happen to know the volume of 2 mols of CO2? How about the volume
of single bubble from a 1/4" (standard) air line?

Yeh, I've gone off the deep end. I was just thinking that I might be
able to guess the length that a solution could survive and how much CO2
would be available for the tank during that time. Basically, the it won't
change the how often I change the bottles, but I started in Chemistry in
college because I found the numbers intriguing.

Thank you again,

Ken Pinard


"Ken Pinard" wrote in message
...
Hi nice explanation, I do have a couple of questions. Mostly for my own
curious mind.

Since Baking Soda is Basic will it not raise the pH? I know we used it in
chemistry to neutralize the acids (even the stuff I dropped all of the
floor, what a mess ;o)

But since Baking Soda raises the kH, the amount of CO2 that is held in the
water solution will be higher. Thus creating carbonic acid. Which will

lower
the pH.

I wish I remembered my chemistry better, its been 25 years now, I actually
find all these equations fascinating.

As I ponder the effect of alcohol on yeast, while I drink a little wine, I
am wondering what additive can combine with alcohol that will not kill the
yeast or react with CO2? I imagine that the idea has been explored

before.
I just was curious.

Thank you for the explanation and equations, I am going to go over them

with
my old chem books (still got them) and try and get them in my head again.

Ken Pinard (French meaning wine - I have alcohol on the brain


"Morten" wrote in message
...
Folks,

The calculations I did in the previous mail were wrong, I just double
checked them...

Here are the original mail with the right figures...

/Morten


---

The addition of baking soda (2NaHCO3) will not lower the amount of

alcohol
(CH3CH2OH) on the solution unless you put so much if in there that it

lovers
the pH too much below 5 effectually killing the yeast before it gets a
chance to convert the sugar (C6H12O6) to CO2

The chemical reaction (or at least the end result of the yeast's

reduction
of sugar goes like this:

C6H12O6(aq) = 2(CH3CH2OH(aq)) + 2(CO2(g)) + energy (used by yeast)

so, for each mol of sugar you get 2 mol of CO2 and because the molar

weight
of sugar is 180.1572 g/mol and the molar weight of CO2 is 44.0098 g/mol,

you
will get (2 * 44.0098 g/mol) / 180.1572 g/mol = 0.4886 g CO2 for each g

og
sugar.

This is max you can get but because some of the CO2 will stay in the

water
in the yeast reactor you will get a little less than the 0.4886 g CO2 /

g
sugar mentioned above.


Since the molar weight for alcohol (CH3CH2OH) is 46.0688 g/mol you will

get
(2 * 46.0688 g/mol) / (180.1572 g/mol) = 0.5114 g alcohol for each g

sugar
added to the reactor.


But, because the alcohol will kill the yeast if the concentration gets

to
high (depending on which type of yeast is used, common baking yeast will
start to die arround (7% - 8%) we need to make sure that the

concentration
of alcohol is low enough to make sure that all the sugar is consumed

before
the alcohol kills the yeast.


If using 2.0L of water (H2O) = 2000g and 220g og sugar the end

concentration
will be (0.4886 * 220 g ) / (2000 g + 04886 * 220 g) = 0.0533 = 5.33 %

which
will alow the yeast to consume all the sugar and still survive the

alcohol.

Using 220 g of sugar this will yield 0.5114 * 220g = 112.5143 g alcohol

and
0.4886 * 220g = 107.4856 g CO2


When all the sugar is gone the yeast will 'floculate' out of solution

and
sink to the bottom of the yeast container but will not die, so we can

actual
ly re-use the yeast every time we set up another batch of sugar if we
carefully drains the water / alcohol solution from the container and

don't
rinse the container with very hot water killing the yeast in the

process.

In the long run it will benefit the yeast if we used a yeast nutrient

(can
be bought from home brewers shops) to feed the yeast the nutrients that

the
yeast needs to stay healthy for prolonged use.


Because some of the CO2 stays in the water we have a buffer solution

like
this:

CO2 + H2O = H+(aq) + HCO3-(aq)

This process is dependent on temperature and the specific wapor pressure

of
CO2 in the container and the water, but i can't remember how to

calculate
the exact ammount of CO2 in solition given the pressure / temperature of

the
solution, so I'll ignore this bit :-)

When adding baking soda you effectively increases the kH of the solution
which loveres the pH making the environment a little more hostile to the
yeast. If i remember correctly yeast prefers a pH of 5 to 6, but will
survive 4 to 9, so there are some room for pH swings before the yeast

gives
up.

This reaction goes like this:

2NaHCO3 + H2O = 2Na+(aq) + 2HCO3-(aq)


Baking soda can be added to stabilise the pH in the reactor if the water
used have a very lov Kh, but for normal (higher that 4 Kh) water baking

soda
actually makes the conditions for the yeast worse but might prolong the
reaction somewhat purely because some of the yeast will die because of

the
higner pH in the reactor.



I hope this came through as i thought it, if not please dont hesitate to

ask
further questions :-)


Regards

Morten
----



---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.611 / Virus Database: 391 - Release Date: 03/03/2004






  #4   Report Post  
Old 05-03-2004, 04:35 AM
Morten
 
Posts: n/a
Default DIY CO2 system question (Correct calculations)

Ken,

"Ken Pinard" wrote in message
...
Hi nice explanation, I do have a couple of questions. Mostly for my own
curious mind.

Since Baking Soda is Basic will it not raise the pH? I know we used it in
chemistry to neutralize the acids (even the stuff I dropped all of the
floor, what a mess ;o)

But since Baking Soda raises the kH, the amount of CO2 that is held in the
water solution will be higher. Thus creating carbonic acid. Which will

lower
the pH.



You are off course right, Baking Soda is a base and will raise the pH in the
solution which is why it's taking part of the buffer with the carbonic acid
that's gets created when the CO2 gets into solution.

What I was trying to say was that if the pH gets to high the yeast will die
so be carefull if you have very soft water when adding Baking Soda to the
water / sugar / yeast mixture if you insist on using it.


As I ponder the effect of alcohol on yeast, while I drink a little wine, I
am wondering what additive can combine with alcohol that will not kill the
yeast or react with CO2? I imagine that the idea has been explored

before.
I just was curious.


Hmmm, you could properly remove some of the alcohol using activated charcoal
to absorb it, but I'm not sure how the yeast will react to that!


I would think that if you were trying to prolong the proceess you could
lover the temperature a little because the enzymes that the yeast are using
to break down the sugar to alcohol + CO2 are temperature dependent ie,
higher temperature = faster reaction, but keep in mind that the rest of the
yeast cell still has to be kept alive so there would be some limitations as
to low you could go before the yeast dies / hybernates.

Anyone up for some experimentation, something like a controlled temperature
of the reactor and a measurement of the speed of the process. Speed could be
determined by weighing the bottle at start and then daily on a precise scale
because the CO2 will leave the system (reactor) and decrease the weight of
the reactor.


Any takers?




I've weighed the last bottle I set up when it was started last weekend but I
havent done anything to control the temperature, but because I know that the
final alcohol content shouldn't kill the yeast I can assume that all the
sugar will be converted to alcohol and CO2 by weighing the bottle from time
to time I can find when the reaction is finished.



It has been a very long day and I should properly have waited til I was a
little bit more clear headed than now :-)


Regards

Morten






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  #5   Report Post  
Old 05-03-2004, 04:35 AM
Harry Muscle
 
Posts: n/a
Default DIY CO2 system question (Correct calculations)

"Ken Pinard" wrote in message
...
Ok, now I am getting even more curious,

Do you happen to know the volume of 2 mols of CO2? How about the

volume
of single bubble from a 1/4" (standard) air line?

Yeh, I've gone off the deep end. I was just thinking that I might be
able to guess the length that a solution could survive and how much CO2
would be available for the tank during that time. Basically, the it won't
change the how often I change the bott , ut I started in Chemistry in
college because I found the numbers intriguing.

Thank you again,

Ken Pinard


1 mole of CO2 occupies 22.4 litres of space, so 2 moles would be 44.8
litres. The volume of a bubble with a diam f 1/4" (0.635cm) is 0.134
cm2.

So 44.8 litres is 44800 cm2 divide that by 0.134 cm2 you get 334328.36
bubbles.

Hope that helps, and let me know if I made any mistakes.

Harry

P.S. I double checked my math and it seems alright, but I'm curious if
there's some mistake somewhere, cause that many bubbles, at 1 bubble per
second would only last about 3-4 days. It might have something to do with
the fact that bubbles from 1/4" tubing will be smaller than 1/4".




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  #6   Report Post  
Old 05-03-2004, 04:36 AM
Morten
 
Posts: n/a
Default DIY CO2 system question (Correct calculations)

Ken,

"Ken Pinard" wrote in message
...
Ok, now I am getting even more curious,

Do you happen to know the volume of 2 mols of CO2? How about the

volume
of single bubble from a 1/4" (standard) air line?



Well, any ideal gas will have a volume of 22.4 L/mol at 298 Kelvin (25
degrees Celcius) so 44.8 L for 2 mol CO2

Given the example with 200 g sugar and 2.2203 mol CO2 it would give 2.2203
mol * 22.4 L/mol = 49.734 L from 200g sugar at 1 bar.


The exact formula is the ideal gas law: pV=nrT where p=pressure, V=volume,
n=mol gas, r=gas constant and T=temperature in Kelvin. At p=1 bar this gives
V=nrT


I can't find my maths book so I cant remember how to calculate the volume of
a bubble or a ball if we assume that a bubble is ball shaped, it's not but I
think it's close enough :-)


Does anybody remember this or have a old maths book handy?


Regards

Morten


---
Outgoing mail is certified Virus Free.
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Version: 6.0.611 / Virus Database: 391 - Release Date: 03/03/2004


  #7   Report Post  
Old 05-03-2004, 04:36 AM
Morten
 
Posts: n/a
Default DIY CO2 system question (Correct calculations)

Folks,

The calculations I did in the previous mail were wrong, I just double
checked them...

Here are the original mail with the right figures...

/Morten


---

The addition of baking soda (2NaHCO3) will not lower the amount of alcohol
(CH3CH2OH) on the solution unless you put so much if in there that it lovers
the pH too much below 5 effectually killing the yeast before it gets a
chance to convert the sugar (C6H12O6) to CO2

The chemical reaction (or at least the end result of the yeast's reduction
of sugar goes like this:

C6H12O6(aq) = 2(CH3CH2OH(aq)) + 2(CO2(g)) + energy (used by yeast)

so, for each mol of sugar you get 2 mol of CO2 and because the molar weight
of sugar is 180.1572 g/mol and the molar weight of CO2 is 44.0098 g/mol, you
will get (2 * 44.0098 g/mol) / 180.1572 g/mol = 0.4886 g CO2 for each g og
sugar.

This is max you can get but because some of the CO2 will stay in the water
in the yeast reactor you will get a little less than the 0.4886 g CO2 / g
sugar mentioned above.


Since the molar weight for alcohol (CH3CH2OH) is 46.0688 g/mol you will get
(2 * 46.0688 g/mol) / (180.1572 g/mol) = 0.5114 g alcohol for each g sugar
added to the reactor.


But, because the alcohol will kill the yeast if the concentration gets to
high (depending on which type of yeast is used, common baking yeast will
start to die arround (7% - 8%) we need to make sure that the concentration
of alcohol is low enough to make sure that all the sugar is consumed before
the alcohol kills the yeast.


If using 2.0L of water (H2O) = 2000g and 220g og sugar the end concentration
will be (0.4886 * 220 g ) / (2000 g + 04886 * 220 g) = 0.0533 = 5.33 % which
will alow the yeast to consume all the sugar and still survive the alcohol.

Using 220 g of sugar this will yield 0.5114 * 220g = 112.5143 g alcohol and
0.4886 * 220g = 107.4856 g CO2


When all the sugar is gone the yeast will 'floculate' out of solution and
sink to the bottom of the yeast container but will not die, so we can actual
ly re-use the yeast every time we set up another batch of sugar if we
carefully drains the water / alcohol solution from the container and don't
rinse the container with very hot water killing the yeast in the process.

In the long run it will benefit the yeast if we used a yeast nutrient (can
be bought from home brewers shops) to feed the yeast the nutrients that the
yeast needs to stay healthy for prolonged use.


Because some of the CO2 stays in the water we have a buffer solution like
this:

CO2 + H2O = H+(aq) + HCO3-(aq)

This process is dependent on temperature and the specific wapor pressure of
CO2 in the container and the water, but i can't remember how to calculate
the exact ammount of CO2 in solition given the pressure / temperature of the
solution, so I'll ignore this bit :-)

When adding baking soda you effectively increases the kH of the solution
which loveres the pH making the environment a little more hostile to the
yeast. If i remember correctly yeast prefers a pH of 5 to 6, but will
survive 4 to 9, so there are some room for pH swings before the yeast gives
up.

This reaction goes like this:

2NaHCO3 + H2O = 2Na+(aq) + 2HCO3-(aq)


Baking soda can be added to stabilise the pH in the reactor if the water
used have a very lov Kh, but for normal (higher that 4 Kh) water baking soda
actually makes the conditions for the yeast worse but might prolong the
reaction somewhat purely because some of the yeast will die because of the
higner pH in the reactor.



I hope this came through as i thought it, if not please dont hesitate to ask
further questions :-)


Regards

Morten
----



---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.611 / Virus Database: 391 - Release Date: 03/03/2004


  #8   Report Post  
Old 05-03-2004, 04:36 AM
Harry Muscle
 
Posts: n/a
Default DIY CO2 system question (Correct calculations)

"Morten" wrote in message
...
Ken,

"Ken Pinard" wrote in message
...
Ok, now I am getting even more curious,

Do you happen to know the volume of 2 mols of CO2? How about the

volume
of single bubble from a 1/4" (standard) air line?



Well, any ideal gas will have a volume of 22.4 L/mol at 298 Kelvin (25
degrees Celcius) so 44.8 L for 2 mol CO2

Given the example with 200 g sugar and 2.2203 mol CO2 it would give 2.2203
mol * 22.4 L/mol = 49.734 L from 200g sugar at 1 bar.


The exact formula is the ideal gas law: pV=nrT where p=pressure, V=volume,
n=mol gas, r=gas constant and T=temperature in Kelvin. At p=1 bar this

gives
V=nrT


I can't find my maths book so I cant remember how to calculate the volume

of
a bubble or a ball if we assume that a bubble is ball shaped, it's not but

I
think it's close enough :-)


Does anybody remember this or have a old maths book handy?


Regards

Morten


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According to google the volume of a sphere is 4/3 * pi * r^3.

Harry




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  #9   Report Post  
Old 05-03-2004, 04:36 AM
Ken Pinard
 
Posts: n/a
Default DIY CO2 system question (Correct calculations)

I took out my magnifying glass and my daughters plastic ruler and came up
with the opening at .4 cm. So redoing the math you put forword (thank you by
the way):

volume=4/3*pi*r3
..4 cm opening creats a bubble of (4/3*3.14159 * (.2*.2*.2) = .0335 cm3
and the number of days:
44800 cm3/.0335cm2 = 1336902.6 bubbles then at 1/sec = 15.5 days

Of course this assumes all CO2 is released. All sugar is converted and the
yeast does not die in its own creations. But it does say that the maximum it
will last at 1/sec is 15 days. So depending on tempature the rate of
production can be changed. thus changing the length that the generator will
work. This of course is avoiding the discussion of the other variables of
alochol posioning of the yeast and CO2 concentration in the solution.

As the great philospher Col. Klink said "Very Interesting".

Thank you for the information, it definitly helps me understand what is
going on.

Ken

Useful: http://grapevine.abe.msstate.edu/~ft...tor/index.html

"Harry Muscle" wrote in message
...
"Ken Pinard" wrote in message
...
Ok, now I am getting even more curious,

Do you happen to know the volume of 2 mols of CO2? How about the

volume
of single bubble from a 1/4" (standard) air line?

Yeh, I've gone off the deep end. I was just thinking that I might be
able to guess the length that a solution could survive and how much CO2
would be available for the tank during that time. Basically, the it

won't
change the how often I change the bott , ut I started in Chemistry in
college because I found the numbers intriguing.

Thank you again,

Ken Pinard


1 mole of CO2 occupies 22.4 litres of space, so 2 moles would be 44.8
litres. The volume of a bubble with a diam f 1/4" (0.635cm) is 0.134
cm2.



So 44.8 litres is 44800 cm2 divide that by 0.134 cm2 you get 334328.36
bubbles.

44800/.0335 = 1336902.6 bubbles at 1/sec = 15.5 days

Hope that helps, and let me know if I made any mistakes.

Harry

P.S. I double checked my math and it seems alright, but I'm curious if
there's some mistake somewhere, cause that many bubbles, at 1 bubble per
second would only last about 3-4 days. It might have something to do with
the fact that bubbles from 1/4" tubing will be smaller than 1/4".




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  #10   Report Post  
Old 05-03-2004, 04:36 AM
Ken Pinard
 
Posts: n/a
Default DIY CO2 system question (Correct calculations)

Morten,
Sorry, I meant to say the Baking soda would raise the pH. So much for
typing and installing operating systems at the same time

Thanks again for the information I truely enjoyed it.

Ken

"Morten" wrote in message
...
Ken,

"Ken Pinard" wrote in message
...
Hi nice explanation, I do have a couple of questions. Mostly for my own
curious mind.

Since Baking Soda is Basic will it not raise the pH? I know we used it

in
chemistry to neutralize the acids (even the stuff I dropped all of the
floor, what a mess ;o)

But since Baking Soda raises the kH, the amount of CO2 that is held in

the
water solution will be higher. Thus creating carbonic acid. Which will

lower
the pH.



You are off course right, Baking Soda is a base and will raise the pH in

the
solution which is why it's taking part of the buffer with the carbonic

acid
that's gets created when the CO2 gets into solution.

What I was trying to say was that if the pH gets to high the yeast will

die
so be carefull if you have very soft water when adding Baking Soda to the
water / sugar / yeast mixture if you insist on using it.


As I ponder the effect of alcohol on yeast, while I drink a little wine,

I
am wondering what additive can combine with alcohol that will not kill

the
yeast or react with CO2? I imagine that the idea has been explored

before.
I just was curious.


Hmmm, you could properly remove some of the alcohol using activated

charcoal
to absorb it, but I'm not sure how the yeast will react to that!


I would think that if you were trying to prolong the proceess you could
lover the temperature a little because the enzymes that the yeast are

using
to break down the sugar to alcohol + CO2 are temperature dependent ie,
higher temperature = faster reaction, but keep in mind that the rest of

the
yeast cell still has to be kept alive so there would be some limitations

as
to low you could go before the yeast dies / hybernates.

Anyone up for some experimentation, something like a controlled

temperature
of the reactor and a measurement of the speed of the process. Speed could

be
determined by weighing the bottle at start and then daily on a precise

scale
because the CO2 will leave the system (reactor) and decrease the weight of
the reactor.


Any takers?




I've weighed the last bottle I set up when it was started last weekend but

I
havent done anything to control the temperature, but because I know that

the
final alcohol content shouldn't kill the yeast I can assume that all the
sugar will be converted to alcohol and CO2 by weighing the bottle from

time
to time I can find when the reaction is finished.



It has been a very long day and I should properly have waited til I was a
little bit more clear headed than now :-)


Regards

Morten






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  #11   Report Post  
Old 05-03-2004, 04:37 AM
bannor
 
Posts: n/a
Default DIY CO2 system question (Correct calculations)

On Thu, 4 Mar 2004 18:35:05 -0000, "Morten"
wrote:
snip
The addition of baking soda (2NaHCO3) will not lower the amount of alcohol
(CH3CH2OH) on the solution unless you put so much if in there that it lovers
the pH too much below 5 effectually killing the yeast before it gets a
chance to convert the sugar (C6H12O6) to CO2

The chemical reaction (or at least the end result of the yeast's reduction
of sugar goes like this:

C6H12O6(aq) = 2(CH3CH2OH(aq)) + 2(CO2(g)) + energy (used by yeast)

so, for each mol of sugar you get 2 mol of CO2 and because the molar weight
of sugar is 180.1572 g/mol and the molar weight of CO2 is 44.0098 g/mol, you
will get (2 * 44.0098 g/mol) / 180.1572 g/mol = 0.4886 g CO2 for each g og
sugar.

This is max you can get but because some of the CO2 will stay in the water
in the yeast reactor you will get a little less than the 0.4886 g CO2 / g
sugar mentioned above.

Since the molar weight for alcohol (CH3CH2OH) is 46.0688 g/mol you will get
(2 * 46.0688 g/mol) / (180.1572 g/mol) = 0.5114 g alcohol for each g sugar
added to the reactor.

But, because the alcohol will kill the yeast if the concentration gets to
high (depending on which type of yeast is used, common baking yeast will
start to die arround (7% - 8%) we need to make sure that the concentration
of alcohol is low enough to make sure that all the sugar is consumed before
the alcohol kills the yeast.

If using 2.0L of water (H2O) = 2000g and 220g og sugar the end concentration
will be (0.4886 * 220 g ) / (2000 g + 04886 * 220 g) = 0.0533 = 5.33 % which
will alow the yeast to consume all the sugar and still survive the alcohol.

Using 220 g of sugar this will yield 0.5114 * 220g = 112.5143 g alcohol and
0.4886 * 220g = 107.4856 g CO2

When all the sugar is gone the yeast will 'floculate' out of solution and
sink to the bottom of the yeast container but will not die, so we can actual
ly re-use the yeast every time we set up another batch of sugar if we
carefully drains the water / alcohol solution from the container and don't
rinse the container with very hot water killing the yeast in the process.

In the long run it will benefit the yeast if we used a yeast nutrient (can
be bought from home brewers shops) to feed the yeast the nutrients that the
yeast needs to stay healthy for prolonged use.

Because some of the CO2 stays in the water we have a buffer solution like
this:
CO2 + H2O = H+(aq) + HCO3-(aq)

This process is dependent on temperature and the specific wapor pressure of
CO2 in the container and the water, but i can't remember how to calculate
the exact ammount of CO2 in solition given the pressure / temperature of the
solution, so I'll ignore this bit :-)

When adding baking soda you effectively increases the kH of the solution
which loveres the pH making the environment a little more hostile to the
yeast. If i remember correctly yeast prefers a pH of 5 to 6, but will
survive 4 to 9, so there are some room for pH swings before the yeast gives
up.

This reaction goes like this:
2NaHCO3 + H2O = 2Na+(aq) + 2HCO3-(aq)

Baking soda can be added to stabilise the pH in the reactor if the water
used have a very lov Kh, but for normal (higher that 4 Kh) water baking soda
actually makes the conditions for the yeast worse but might prolong the
reaction somewhat purely because some of the yeast will die because of the
higner pH in the reactor.

I hope this came through as i thought it, if not please dont hesitate to ask
further questions :-)
Regards
Morten



Wow... thanks Morten!... This is definately a keeper and I think your
explanation is easier to read than the one that was provided in that
other link...which I remember reading during my investigations of
going DIY CO2... I guess I just didn't pay close enough attention to
the chemistry details.

My suggestion regarding adding the baking soda came from reading that
suggestion at 'the Krib' in the DIY CO2 notes etc... guess it was just
an old fishkeepers tale. I have always added it, just a little to
each mixture... now, I can save that extra step. I was, apparently
falsely, under the impression that the baking soda would adsorb the
alcohol. Oh well... I never took chemistry... never made it past 10th
grade, got kicked out of school for knocking down the principal when
he started calling a female student names that I doubt you would hear
in a prison! Anyway, education since has been non graduate level,
independant studies in college. IE, no class requirements, just going
for the knowledge, not the credits to get a degree and since I have no
practical use for chemistry, I never bothered to take those sorts of
courses... I may have to add some basic chemistry in over the next
couple semesters....
  #12   Report Post  
Old 05-03-2004, 04:37 AM
Ken Pinard
 
Posts: n/a
Default DIY CO2 system question (Correct calculations)

Hi nice explanation, I do have a couple of questions. Mostly for my own
curious mind.

Since Baking Soda is Basic will it not raise the pH? I know we used it in
chemistry to neutralize the acids (even the stuff I dropped all of the
floor, what a mess ;o)

But since Baking Soda raises the kH, the amount of CO2 that is held in the
water solution will be higher. Thus creating carbonic acid. Which will lower
the pH.

I wish I remembered my chemistry better, its been 25 years now, I actually
find all these equations fascinating.

As I ponder the effect of alcohol on yeast, while I drink a little wine, I
am wondering what additive can combine with alcohol that will not kill the
yeast or react with CO2? I imagine that the idea has been explored before.
I just was curious.

Thank you for the explanation and equations, I am going to go over them with
my old chem books (still got them) and try and get them in my head again.

Ken Pinard (French meaning wine - I have alcohol on the brain


"Morten" wrote in message
...
Folks,

The calculations I did in the previous mail were wrong, I just double
checked them...

Here are the original mail with the right figures...

/Morten


---

The addition of baking soda (2NaHCO3) will not lower the amount of alcohol
(CH3CH2OH) on the solution unless you put so much if in there that it

lovers
the pH too much below 5 effectually killing the yeast before it gets a
chance to convert the sugar (C6H12O6) to CO2

The chemical reaction (or at least the end result of the yeast's reduction
of sugar goes like this:

C6H12O6(aq) = 2(CH3CH2OH(aq)) + 2(CO2(g)) + energy (used by yeast)

so, for each mol of sugar you get 2 mol of CO2 and because the molar

weight
of sugar is 180.1572 g/mol and the molar weight of CO2 is 44.0098 g/mol,

you
will get (2 * 44.0098 g/mol) / 180.1572 g/mol = 0.4886 g CO2 for each g og
sugar.

This is max you can get but because some of the CO2 will stay in the water
in the yeast reactor you will get a little less than the 0.4886 g CO2 / g
sugar mentioned above.


Since the molar weight for alcohol (CH3CH2OH) is 46.0688 g/mol you will

get
(2 * 46.0688 g/mol) / (180.1572 g/mol) = 0.5114 g alcohol for each g sugar
added to the reactor.


But, because the alcohol will kill the yeast if the concentration gets to
high (depending on which type of yeast is used, common baking yeast will
start to die arround (7% - 8%) we need to make sure that the concentration
of alcohol is low enough to make sure that all the sugar is consumed

before
the alcohol kills the yeast.


If using 2.0L of water (H2O) = 2000g and 220g og sugar the end

concentration
will be (0.4886 * 220 g ) / (2000 g + 04886 * 220 g) = 0.0533 = 5.33 %

which
will alow the yeast to consume all the sugar and still survive the

alcohol.

Using 220 g of sugar this will yield 0.5114 * 220g = 112.5143 g alcohol

and
0.4886 * 220g = 107.4856 g CO2


When all the sugar is gone the yeast will 'floculate' out of solution and
sink to the bottom of the yeast container but will not die, so we can

actual
ly re-use the yeast every time we set up another batch of sugar if we
carefully drains the water / alcohol solution from the container and don't
rinse the container with very hot water killing the yeast in the process.

In the long run it will benefit the yeast if we used a yeast nutrient (can
be bought from home brewers shops) to feed the yeast the nutrients that

the
yeast needs to stay healthy for prolonged use.


Because some of the CO2 stays in the water we have a buffer solution like
this:

CO2 + H2O = H+(aq) + HCO3-(aq)

This process is dependent on temperature and the specific wapor pressure

of
CO2 in the container and the water, but i can't remember how to calculate
the exact ammount of CO2 in solition given the pressure / temperature of

the
solution, so I'll ignore this bit :-)

When adding baking soda you effectively increases the kH of the solution
which loveres the pH making the environment a little more hostile to the
yeast. If i remember correctly yeast prefers a pH of 5 to 6, but will
survive 4 to 9, so there are some room for pH swings before the yeast

gives
up.

This reaction goes like this:

2NaHCO3 + H2O = 2Na+(aq) + 2HCO3-(aq)


Baking soda can be added to stabilise the pH in the reactor if the water
used have a very lov Kh, but for normal (higher that 4 Kh) water baking

soda
actually makes the conditions for the yeast worse but might prolong the
reaction somewhat purely because some of the yeast will die because of the
higner pH in the reactor.



I hope this came through as i thought it, if not please dont hesitate to

ask
further questions :-)


Regards

Morten
----



---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.611 / Virus Database: 391 - Release Date: 03/03/2004




  #13   Report Post  
Old 05-03-2004, 04:37 AM
Ken Pinard
 
Posts: n/a
Default DIY CO2 system question (Correct calculations)

Ok, now I am getting even more curious,

Do you happen to know the volume of 2 mols of CO2? How about the volume
of single bubble from a 1/4" (standard) air line?

Yeh, I've gone off the deep end. I was just thinking that I might be
able to guess the length that a solution could survive and how much CO2
would be available for the tank during that time. Basically, the it won't
change the how often I change the bottles, but I started in Chemistry in
college because I found the numbers intriguing.

Thank you again,

Ken Pinard


"Ken Pinard" wrote in message
...
Hi nice explanation, I do have a couple of questions. Mostly for my own
curious mind.

Since Baking Soda is Basic will it not raise the pH? I know we used it in
chemistry to neutralize the acids (even the stuff I dropped all of the
floor, what a mess ;o)

But since Baking Soda raises the kH, the amount of CO2 that is held in the
water solution will be higher. Thus creating carbonic acid. Which will

lower
the pH.

I wish I remembered my chemistry better, its been 25 years now, I actually
find all these equations fascinating.

As I ponder the effect of alcohol on yeast, while I drink a little wine, I
am wondering what additive can combine with alcohol that will not kill the
yeast or react with CO2? I imagine that the idea has been explored

before.
I just was curious.

Thank you for the explanation and equations, I am going to go over them

with
my old chem books (still got them) and try and get them in my head again.

Ken Pinard (French meaning wine - I have alcohol on the brain


"Morten" wrote in message
...
Folks,

The calculations I did in the previous mail were wrong, I just double
checked them...

Here are the original mail with the right figures...

/Morten


---

The addition of baking soda (2NaHCO3) will not lower the amount of

alcohol
(CH3CH2OH) on the solution unless you put so much if in there that it

lovers
the pH too much below 5 effectually killing the yeast before it gets a
chance to convert the sugar (C6H12O6) to CO2

The chemical reaction (or at least the end result of the yeast's

reduction
of sugar goes like this:

C6H12O6(aq) = 2(CH3CH2OH(aq)) + 2(CO2(g)) + energy (used by yeast)

so, for each mol of sugar you get 2 mol of CO2 and because the molar

weight
of sugar is 180.1572 g/mol and the molar weight of CO2 is 44.0098 g/mol,

you
will get (2 * 44.0098 g/mol) / 180.1572 g/mol = 0.4886 g CO2 for each g

og
sugar.

This is max you can get but because some of the CO2 will stay in the

water
in the yeast reactor you will get a little less than the 0.4886 g CO2 /

g
sugar mentioned above.


Since the molar weight for alcohol (CH3CH2OH) is 46.0688 g/mol you will

get
(2 * 46.0688 g/mol) / (180.1572 g/mol) = 0.5114 g alcohol for each g

sugar
added to the reactor.


But, because the alcohol will kill the yeast if the concentration gets

to
high (depending on which type of yeast is used, common baking yeast will
start to die arround (7% - 8%) we need to make sure that the

concentration
of alcohol is low enough to make sure that all the sugar is consumed

before
the alcohol kills the yeast.


If using 2.0L of water (H2O) = 2000g and 220g og sugar the end

concentration
will be (0.4886 * 220 g ) / (2000 g + 04886 * 220 g) = 0.0533 = 5.33 %

which
will alow the yeast to consume all the sugar and still survive the

alcohol.

Using 220 g of sugar this will yield 0.5114 * 220g = 112.5143 g alcohol

and
0.4886 * 220g = 107.4856 g CO2


When all the sugar is gone the yeast will 'floculate' out of solution

and
sink to the bottom of the yeast container but will not die, so we can

actual
ly re-use the yeast every time we set up another batch of sugar if we
carefully drains the water / alcohol solution from the container and

don't
rinse the container with very hot water killing the yeast in the

process.

In the long run it will benefit the yeast if we used a yeast nutrient

(can
be bought from home brewers shops) to feed the yeast the nutrients that

the
yeast needs to stay healthy for prolonged use.


Because some of the CO2 stays in the water we have a buffer solution

like
this:

CO2 + H2O = H+(aq) + HCO3-(aq)

This process is dependent on temperature and the specific wapor pressure

of
CO2 in the container and the water, but i can't remember how to

calculate
the exact ammount of CO2 in solition given the pressure / temperature of

the
solution, so I'll ignore this bit :-)

When adding baking soda you effectively increases the kH of the solution
which loveres the pH making the environment a little more hostile to the
yeast. If i remember correctly yeast prefers a pH of 5 to 6, but will
survive 4 to 9, so there are some room for pH swings before the yeast

gives
up.

This reaction goes like this:

2NaHCO3 + H2O = 2Na+(aq) + 2HCO3-(aq)


Baking soda can be added to stabilise the pH in the reactor if the water
used have a very lov Kh, but for normal (higher that 4 Kh) water baking

soda
actually makes the conditions for the yeast worse but might prolong the
reaction somewhat purely because some of the yeast will die because of

the
higner pH in the reactor.



I hope this came through as i thought it, if not please dont hesitate to

ask
further questions :-)


Regards

Morten
----



---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.611 / Virus Database: 391 - Release Date: 03/03/2004






  #14   Report Post  
Old 05-03-2004, 04:38 AM
Morten
 
Posts: n/a
Default DIY CO2 system question (Correct calculations)

Ken,

"Ken Pinard" wrote in message
...
Hi nice explanation, I do have a couple of questions. Mostly for my own
curious mind.

Since Baking Soda is Basic will it not raise the pH? I know we used it in
chemistry to neutralize the acids (even the stuff I dropped all of the
floor, what a mess ;o)

But since Baking Soda raises the kH, the amount of CO2 that is held in the
water solution will be higher. Thus creating carbonic acid. Which will

lower
the pH.



You are off course right, Baking Soda is a base and will raise the pH in the
solution which is why it's taking part of the buffer with the carbonic acid
that's gets created when the CO2 gets into solution.

What I was trying to say was that if the pH gets to high the yeast will die
so be carefull if you have very soft water when adding Baking Soda to the
water / sugar / yeast mixture if you insist on using it.


As I ponder the effect of alcohol on yeast, while I drink a little wine, I
am wondering what additive can combine with alcohol that will not kill the
yeast or react with CO2? I imagine that the idea has been explored

before.
I just was curious.


Hmmm, you could properly remove some of the alcohol using activated charcoal
to absorb it, but I'm not sure how the yeast will react to that!


I would think that if you were trying to prolong the proceess you could
lover the temperature a little because the enzymes that the yeast are using
to break down the sugar to alcohol + CO2 are temperature dependent ie,
higher temperature = faster reaction, but keep in mind that the rest of the
yeast cell still has to be kept alive so there would be some limitations as
to low you could go before the yeast dies / hybernates.

Anyone up for some experimentation, something like a controlled temperature
of the reactor and a measurement of the speed of the process. Speed could be
determined by weighing the bottle at start and then daily on a precise scale
because the CO2 will leave the system (reactor) and decrease the weight of
the reactor.


Any takers?




I've weighed the last bottle I set up when it was started last weekend but I
havent done anything to control the temperature, but because I know that the
final alcohol content shouldn't kill the yeast I can assume that all the
sugar will be converted to alcohol and CO2 by weighing the bottle from time
to time I can find when the reaction is finished.



It has been a very long day and I should properly have waited til I was a
little bit more clear headed than now :-)


Regards

Morten






---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.611 / Virus Database: 391 - Release Date: 03/03/2004


  #15   Report Post  
Old 05-03-2004, 04:41 AM
Harry Muscle
 
Posts: n/a
Default DIY CO2 system question (Correct calculations)

"Ken Pinard" wrote in message
...
Ok, now I am getting even more curious,

Do you happen to know the volume of 2 mols of CO2? How about the

volume
of single bubble from a 1/4" (standard) air line?

Yeh, I've gone off the deep end. I was just thinking that I might be
able to guess the length that a solution could survive and how much CO2
would be available for the tank during that time. Basically, the it won't
change the how often I change the bott , ut I started in Chemistry in
college because I found the numbers intriguing.

Thank you again,

Ken Pinard


1 mole of CO2 occupies 22.4 litres of space, so 2 moles would be 44.8
litres. The volume of a bubble with a diam f 1/4" (0.635cm) is 0.134
cm2.

So 44.8 litres is 44800 cm2 divide that by 0.134 cm2 you get 334328.36
bubbles.

Hope that helps, and let me know if I made any mistakes.

Harry

P.S. I double checked my math and it seems alright, but I'm curious if
there's some mistake somewhere, cause that many bubbles, at 1 bubble per
second would only last about 3-4 days. It might have something to do with
the fact that bubbles from 1/4" tubing will be smaller than 1/4".




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