Curious about cO2

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BenVanned

BenVanned

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A few questions. Has anyone ever tried to collect and store the co2 from a brew?

On average how much co2 is produced per 5 gallon batch?

How many psi does it actually take to bust a filled 12oz bottle?

How many psi would it take to bust an empty 12oz bottle?
 
No. But I have stored methane created from drinking it for very short periods before igniting it. I hope this helps.
 
BenVanned said:
A few questions. Has anyone ever tried to collect and store the co2 from a brew?
Click to expand...

I am afraid I can't answer your other questions (the amount of pressure a glass bottle can take depends on the bottle type), but CO2 recovery is done in some commercial breweries, such as Sierra Nevada. I don't know if this can be done at home - you'd need some sort of compressor to collect and store the CO2 in a tank. It'd probably be cost-prohibitive.
 
There's lots of esters and sulfur compounds that get driven off in the fermentation/CO2 off gassing that I personally wouldn't want back in my beer. Not sure how Sierra Nevada's process works, but dimensions of scale definitely help there.

I would think putting the energy into compressing the CO2 would have diminishing returns.

As for your bottle question, I don't know the PSI, but the weak point in a bottle is generally at the bottom, so a filled bottle which has non-compressible liquid could handle much more pressure than an empty bottle. The top neck of the bottle is pretty strong.

There's rumor of an MIT paper on PSI ratings of beer bottles, but I haven't been able to find it.
 
To stay in line with Reinheitsgebot in Germany they collect CO2 from the brew tanks and then pressurise it back into the beer afterwards so they are not adding external CO2.
 
BenVanned said:
A few questions. Has anyone ever tried to collect and store the co2 from a brew?

On average how much co2 is produced per 5 gallon batch?

How many psi does it actually take to bust a filled 12oz bottle?

How many psi would it take to bust an empty 12oz bottle?
Click to expand...

For question 1; It would be easier for the homebrewer to implement a closed pressure fermentation than try to collect CO2 gas for carbonation down stream
 
BenVanned said:
A few questions. Has anyone ever tried to collect and store the co2 from a brew?

On average how much co2 is produced per 5 gallon batch?

How many psi does it actually take to bust a filled 12oz bottle?

How many psi would it take to bust an empty 12oz bottle?
Click to expand...

I calculated the volume of CO2 produced in an average 5 gallon batch before and am sure that post is around here somewhere. It was from a couple of years ago when there were folks who were stating that fermentation was a mysterious process and could occur completely without any CO2 production :confused:

It's a simple calculation based on the fact that one mole of a simple monosaccharide such as fructose and glucose is converted into 2 moles of EtOH and 2 moles of CO2 so you calculate a pretty good estimate of the number of moles of CO2 and calculate it's volume at STP.

I've never heard of anyone trying to store it but there were some folks who were interested in using it in a synergistic fashion by storing their carboy's in a tent for their indoor plant cultivation projects since some of the more popular plants grown by these folks benefit from being in a high CO2 environment.
 
IXVolt said:
As for your bottle question, I don't know the PSI, but the weak point in a bottle is generally at the bottom, so a filled bottle which has non-compressible liquid could handle much more pressure than an empty bottle. The top neck of the bottle is pretty strong.
Click to expand...

:drunk:

Dude - na-ah. Regardless of the contents, the bottle sees the same psi. 10 psi in an empty is the same as 10 psi in a full.
 
brewit2it said:
I calculated the volume of CO2 produced in an average 5 gallon batch before and am sure that post is around here somewhere. It was from a couple of years ago when there were folks who were stating that fermentation was a mysterious process and could occur completely without any CO2 production :confused:

It's a simple calculation based on the fact that one mole of a simple monosaccharide such as fructose and glucose is converted into 2 moles of EtOH and 2 moles of CO2 so you calculate a pretty good estimate of the number of moles of CO2 and calculate it's volume at STP.

I've never heard of anyone trying to store it but there were some folks who were interested in using it in a synergistic fashion by storing their carboy's in a tent for their indoor plant cultivation projects since some of the more popular plants grown by these folks benefit from being in a high CO2 environment.
Click to expand...

You could go the chemistry angle, or if you assume that the vast majority of the off-gassed material is CO2, I think you could get pretty close just by taking the difference of the OG and FG. If you have a 1.050 beer that ferments down to 1.010, you're looking at a .040 delta. Multiply by 8.3 lbs/gal and 5 gallons, and the beer has "lost" about 1.6 lbs during fermentation.

Of course that doesn't account for the esters and sulfur compounds mentioned above, or any proteins that may precipitate out, but I'm guessing that it'll get you in the ballpark. I'd be interested to see how that compares to your method if you ever dig up the post.
 
Huff360 said:
:drunk:

Dude - na-ah. Regardless of the contents, the bottle sees the same psi. 10 psi in an empty is the same as 10 psi in a full.
Click to expand...

Solution of gas in fluids would prove you wrong. Next time you have a highly carbonated bottle of beer, shake it for a few minutes, and tell me what you get. You can try it with a 10 PSI empty bottle and compare. :D

MC
 
The pressure is the same. If you had a bottle of beer that was sealed and previously carbonated and had a pressure gauge on the headspace, then shook the bottle, the gauge wouldn't change. It only seems like the pressure is higher because the bubbles you form during shaking provides a ton of nucleation points and the CO2 comes out of solution rapidly if you open the top before the bubbles go away.
 
gr8shandini said:
You could go the chemistry angle, or if you assume that the vast majority of the off-gassed material is CO2, I think you could get pretty close just by taking the difference of the OG and FG. If you have a 1.050 beer that ferments down to 1.010, you're looking at a .040 delta. Multiply by 8.3 lbs/gal and 5 gallons, and the beer has "lost" about 1.6 lbs during fermentation.

Of course that doesn't account for the esters and sulfur compounds mentioned above, or any proteins that may precipitate out, but I'm guessing that it'll get you in the ballpark. I'd be interested to see how that compares to your method if you ever dig up the post.
Click to expand...

I couldn't find my post because it wasn't a thread I started but rather a reply, but I think your estimate is very close. You didn't account for the ethanol production which has a lower density than water and makes up 5% of the final volume so if you take that into account you get something like 1.66 lb CO2.

So if we want to know the volume of CO2 at room temp instead of weight we can use the idea gas law which says pV=nRT

we need to calculate the number of moles in our 1.66 lb which is about 750 gms and CO2 is 44 gm per mole so we have about 17 mole CO2.

V in liters = 17mol x .08206 L x atm x 294.3 Kelvin (70 degrees F)/Kelvin mol 1 atm

So about 410 liters CO2 at room temp and sea level produced per average 5 gallon batch.
 
IXVolt said:
As for your bottle question, I don't know the PSI, but the weak point in a bottle is generally at the bottom, so a filled bottle which has non-compressible liquid could handle much more pressure than an empty bottle. The top neck of the bottle is pretty strong.
Click to expand...

Huff360 said:
:drunk:

Dude - na-ah. Regardless of the contents, the bottle sees the same psi. 10 psi in an empty is the same as 10 psi in a full.
Click to expand...

Misplaced_Canuck said:
Solution of gas in fluids would prove you wrong. Next time you have a highly carbonated bottle of beer, shake it for a few minutes, and tell me what you get. You can try it with a 10 PSI empty bottle and compare. :D

MC
Click to expand...

That has nothing to do with what we were talking about.

He originally said that you could put a higher psi in a filled bottle before it would fail cause the beer somehow protected the weak bottom from the pressure.

Just because there is a non-compressible liquid occupying part of the bottle does not mean that the entire bottle is not under the same pressure. If a bottle fails at X psi, it will fail at X psi. I don't care if it is full of air, beer, or crushed babies.
 

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