How about a CO2 Capture system?

[IowaStateFan]

I rather like playing devil's advocate when people come in advertising their great new ideas. If everyone does nothing but a bunch of back patting, there's no validation or interogation of the theory. Quite frankly, if someone wants to be an innovator, they have to be able to defend their ideas anyway.

Good points, and playing devil's advocate is okay. The problem is when people are just negative, rude, or just trying to be funny without offering constructive criticism. Thankfully, we don't have a lot of that here and when someone does start to get out of hand they get put in their place pretty quickly. I tried to read the linked thread and it was difficult to get thru because of the negative, "can't be done" posts.

 

[WortMonger]

I completely agree with having to defend your idea. I do hate it when people don't ask anything and just say it won't work because. Because is not an answer. Because and information proving because, is! I get more information from an intelligent person quizzing me on how and why than I ever would would some completely uninterested a$$hole continually asking why anyone would want to do something. Sometimes a brain needs a challenge, and doing things another way is a way to vent some built up intellect. I think of it as it taking 3,000,000,000,000+ workable but not economical ideas that give birth to the 1 world changing event of our existance.

I was wondering though, if one collected CO2, what would be powerful enough to compress a usable amount into a normal CO2 bottle. I don't think I would like any system that didn't take me to an easily portable supply. I guess I am wondering if I could fill my new aluminum 5# bottle with 2.5# reclaimed CO2 using a safe vacuum pump (one end attached to the collection device and the other to the bottle on a scale to weight the input CO2)? I have no idea if something like the ####pump they talked about would provide that much compression to a bottle of CO2 you were filling.

 

[WortMonger]

Good points, and playing devil's advocate is okay. The problem is when people are just negative, rude, or just trying to be funny without offering constructive criticism. Thankfully, we don't have a lot of that here and when someone does start to get out of hand they get put in their place pretty quickly. I tried to read the linked thread and it was difficult to get thru because of the negative, "can't be done" posts.

Exactly, I don't understand why the mods didn't just erase non-relevant clutter from that thread. If your gonna be an a$$, at least offer something besides your witty sarcasm. I love witty sarcasm, followed by a practical or at least remotely intelligent response to the question at hand. People feel the need to say something, when all they had to do was think it was stupid and click the back button on the browser. I am glad it doesn't get like that here. This is a community of respect and everyone should pounce on a naysayer that can't back up their naysaying with science or experience. BierMuncher is great in the way he does it, prime example of respect but complete honesty about the product. Trying to sell something and trying to come up with something are a little different, but when a person ask for specific information about a broad idea and you have the info but don't like the whole idea.... just tell them the part they are asking and quietly keep some opinions to yourself (not BeirMuncher yourself as a universal ).

 

[olllllo]

"Can't be done," is used quite lazily here as short-hand for:
Can't be done - economically.
Can't be done - by the average homebrewer with commonly available resources.
Can't be done - in a time effecive manner.

Even when these are explicitly stated, on the flip side, people sometimes only read the, "can't be done," part.

We should all be more clear.

 

[macs]

I guess I am wondering if I could fill my new aluminum 5# bottle with 2.5# reclaimed CO2 using a safe vacuum pump (one end attached to the collection device and the other to the bottle on a scale to weight the input CO2)? I have no idea if something like the ####pump they talked about would provide that much compression to a bottle of CO2 you were filling.

I don't think an average vacuum pump would be able to compress the CO2 to the levels required since it is designed to evacuate rather than pressurize. I have an old "Slurpie" machine compressor that I salvaged from a creek after a major flood years ago that will easily hit 300psi, but 800-900 psi or more would be a real challenge. Hmmm...what if you had a way to super-cool the CO2 and the tank prior to filling? That should reduce the pressure required to liquify the CO2. There used to be a book available on the techniques used for the liquification of gases sold by Lindsay Publishing years ago. Not sure if it's still available or not.

 

[shafferpilot]

I've been thinking about compressing the gas and the best i have come up with is a Briggs and Stratton motor, or something similar. There are certainly problems with that like: oil vapors making their way into the bottle, small motors don't seal perfectly so it has to be turning at operating speed to build the kind of pressure we're talking about. Plus it would take a pretty stout electric or gas motor to turn the briggs.

I was thinking that the exhaust valve stem could be cut off and the valve head welded into the block to cover the exhaust opening. Then piping is plumbed to the spark plug hole, run through somekind of checkvalve and a filtering setup; then to the bottle.

I knew a guy who made an air compressor that way, but the motor he used was REALLY old and was barely able to make 250psi. But it worked.

 

[WortMonger]

LOL, I just registered and gave OldFart props for sticking to his fight. I see Hump went there too, lol. I was thinking of a compressor too, but the ones for fridges might put unwanted stuff in the gas. Why does the gas need to be at 800-900 psi? I am wondering if a required volume of CO2, that is however much is needed, could fit in a 5# CO2 tank at a lower pressure that can be obtained by a compressor like you mentioned?

I am asking, lol, why blow up a whole balloon with numerous chestfuls of breath, when you can simply put one breath in the balloon to blow out candles on a cake? <-----The Reinheitsgebot way of getting your birthday wish to come true. If it was possible with a cheap compressor and "enough???" could be fitted into a 5# tank, then who cares if my tank only has 1-2-3#'s of CO2 in it. Crap, what if .25# is all that is needed. It is these numbers that I need to find out.

 

[WortMonger]

I like the cold idea too, all my CO2 produced would be at least 65*F from the start. After I crash cool my beer and relieve any excess carbonation pressure, I would have 35*F CO2. From experience, I go from ~31 psi at 65*F to ~12.7 psi @35*F. I wonder how this would provide for more possibilities in what I am wanting to do, and by wonder I mean you brainiacs that have the numbers better give them up, lol.

Here we go, a specific questions for a brain:
1). How much CO2 is needed to serve a full 15.5 gallon keg, at "lets say" 10 psi with the CO2 being at room temperature of 68*F and the beer keg being at 40*F?
2). How much compression pressure is required from a pump to fill a CO2 tank to said pressure/volume needed in question 1?

 

[shafferpilot]

The problem is that if you don't compress it enough to turn to a liquid there isn't enough to do anything. Open the valve and it will go pfft. and be "empty". CO2 condenses at something like 635psi. If you have the pressure to get 1 lb of CO2 into a bottle, then you have the pressure to get 5 pounds in there too. That's why the high pressure gauge on a CO2 bottle is basically useless. The bottle stays at 600-800 psi for months and when it starts to drop, you have a pint or three to go before it's completely empty.

 

[WortMonger]

Ahhh, I see. That makes sense, but I did read that a 5 gallon corny at 30 psi full of CO2 has enough to serve a 5 gallon keg and leave you with about 6-9 psi remaining in the CO2 keg. So, that being read, could I get say (3) 5-gallon kegs worth of CO2 compressed into a bottle? I am planning a 15.5 Sanke for my collection vessel at 15-30 psi depending on temperature, but more likely 15 psi at 65*F. According to what I read, this should be sufficient to serve a 15.5 gallon Sanke. I wish to put all the CO2 from the Sanke into the 5# bottle. Can I do this, and how much pressure would it take?

 

[Sir Humpsalot]

My SWMBO is more of the science nerd. Sadly, she's more bio than physics, otherwise she'd be on it. Me, I'm more physics... but I really didn't pay all that much attention in class.

I could probably figure it out in a rudimentary way if nobody else has the info more at their fingertips.

And yeah, I'm thinking that 100 psi in a 10 pounder ought to be plenty for a couple cornies. Remember, if you just have 2 kegs, then having enough CO2 for maybe 3 or 4 batches is all we really need for the ideal set up. Afterall, unlike the people who need to make a special trip to go to the gas supply place, we'll be making our CO2 with every batch... so we don't need to "stock up".

It's sort of like the convenience of a quick-e-mart versus buying in bulk at Sam's Club. Except, in this case, the quick-e-mart is free and Sam's Club charges money. :fro:

 

[Bobby_M]

It's all good fun to think about this stuff. Let's look at it this way; atmosphere at sea level is about 15psi give or take so if you open a corny lid, let it equilize to the air and seal it back up, you have 5 gallons (.67 cubic feet) of air at 15psi (1 ATM). Of course, when we think of a tank having a certain PSI, we really mean 1ATM + that pressure because it's always about the differential pressure, not absolute.

Boyle's law basics; Volume of a gas is inversely proportional to its pressure.
Ok, so what if you have a way to turn the volume of the 5 gallon corny into half the space of 2.5 gallons? The pressure will double to 30psi or 2ATM. Do it again, 1.25gallons = 60PSI or 4ATM. That's probably about the same volume as a 5lb CO2 tank now. So, having a 1.25 gallon tank of C02 at 60psi is just about enough to push 5 gallons of beer out of a corny. Maybe not enough though because of pressure needed to maintain your desired carbonation level (probably 12 PSI). By the time 1/2 of the beer is pushed out, you'll be left with about 30psi (+15 absolute) which means beer is about to stop flowing and start going flat. Imagine when all the liquid CO2 has vaporized in a 5lb bottle. You now have about 1 gallon of gas at 600psi. You can imagine why that tank empties so quickly now. The pressure is no longer being replenished.

Even in that simple example, it's going to be difficult to compress to 60psi in a sanitary manner. My idea of using a bladdered expansion tank would work to a degree, but I don't know what the max pressure is. If you fill that sucker to 12psi with the back bladder "open". Close the co2 side, attach 12psi of compressed air on the bladder and you now have that tank size of 12psi but it will stay at that same pressure until the last cubic inch of CO2 is pushed out. We get into false economy debates again here though because what does it cost to run the old air compressor whenever you need to to maintain that 12psi?

 

[macs]

Here we go, a specific questions for a brain:
1). How much CO2 is needed to serve a full 15.5 gallon keg, at "lets say" 10 psi with the CO2 being at room temperature of 68*F and the beer keg being at 40*F?
2). How much compression pressure is required from a pump to fill a CO2 tank to said pressure/volume needed in question 1?

1) Answer: If my calcs are correct, at 10psi and 40*F you would need a total of 4.76 ozs of dissolved CO2 to maintain the carbonation level of 2.3 for 15.5 gallons of beer. Not sure what the volume would be for that much CO2. I'm sure there is a chart or formula for that.
2) Answer: Still working on it.....

 

[WortMonger]

Humm, so it is possible to scale to what I am already using, and will be using to collect the CO2. The only problem seems to be the sanitary compression of CO2 to higher than 60 psi so I can use a smaller CO2 tank.

 

[WortMonger]

1) Answer: If my calcs are correct, at 10psi and 40*F you would need a total of 4.76 ozs of dissolved CO2 to maintain the carbonation level of 2.3 for 15.5 gallons of beer. Not sure what the volume would be for that much CO2. I'm sure there is a chart or formula for that.
2) Answer: Still working on it.....

I was meaning serving already carbonated beer at 10 psi @ 40*F. How much gas was used to serve the eniter keg at these specific examples. 15.5 gallons of 10 psi CO2???? LOL, thanks for the starting info though. See, we are so much more mature than the other boards, and have so much more fun, lol.

 

[Sir Humpsalot]

I just want a cheaper version of one of these....

http://cgi.ebay.com/HOOKAMAX-hookah...ryZ16056QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


I'd say maybe a hobby airbrush compressor might be the best bet. They're generally oilless and will make upwards of 40 PSI. Just need a way to restrict their intake so they aren't collecting the surrounding air...

Oh wait... no you don't. I think I have an idea.... I use plastic carboys as an example as I know they will hold some pressure. I am not suggesting they actually be used to develop high pressures... it's just for the visual...

Two plastic carboys, one higher than the other, connected airtight by a tube. Each carboy has an airtight valve on top. Fill the lower carboy with 5 gallons of star-san, the upper carboy filled with air. Open the valve on the upper carboy to the atmosphere.

The lower carboy's valve is connected to the fermenter. As the fermentation occurs, it displaces the starsan solution until you have 5 gallons of pure CO2 in the lower carboy. No purging is necessary because the entire headspace is consumed by water. So it will be very pure CO2.

Once the lower carboy is full of CO2, it will start bubbling, just like a giant airlock. At this time, hook the compressor (doesn't even have to be oilless) up to the high side. Connect the lower side (full of CO2) to your collection vessel (which will have to get purged in this process). Now start the pump on the high side, which will compress the water back into the lower container, in the process, compressing the CO2 into your collection vessel.

When done, close the valve on your collection vessel and release the pressure from the top of the upper carboy.

 

[macs]

I was meaning serving already carbonated beer at 10 psi @ 40*F. How much gas was used to serve the eniter keg at these specific examples. 15.5 gallons of 10 psi CO2???? LOL, thanks for the starting info though. See, we are so much more mature than the other boards, and have so much more fun, lol.

Oh...sorry....I think the room temp ratio of dissolved alcohol to my brain's volume in cc's is reaching toxic levels. Think I'll have another homebrew...

 

[Bobby_M]

The problem though is that serving is one thing, but long term storage and mantanance of the carbonation level is another. Given that you already figured out how many volumes of carb you wanted, say 2.5 per the pressure/temp chart and arrive at 12psi required. As soon as the pressure drops below that, you're losing carbonation. This wouldn't be an issue if you think you're going to blow through 15 gallons of beer in a night, but otherwise......



To answer your specific brain teaser:
Originally Posted by wortmonger

1). How much CO2 is needed to serve a full 15.5 gallon keg, at "lets say" 10 psi with the CO2 being at room temperature of 68*F and the beer keg being at 40*F?


Really good question and I don't know if I have the knowledge to figure it out. But I'll think out loud to get you started. It's easy enough to apply the initial 10psi to the minut headspace of a full 1/2 barrel keg. It's figuring out how much you have to start with to make sure you END with 10psi minimum. There's probably a neat formula or calculator online to help with Dalton's law (combined gas)... yup http://www.1728.com/combined.htm

If you have 60psi in a 5 gallon corny at 70F, if realeased into 15 gallons at 40F your pressure should end up at 11psi.

Now, if you bring the orginal size down to 1.5 gallons (about the size of a 5lb tank I assume) and leave the pressure the same at 60psi, you could conceivably push the whole keg but you'd end up around 3psi and the beer would be going flat for some time.

In order to hold the full 10psi all the way through, you'd need 175psi in a 1.5gallon container.

Here's the rub. You'll probably have to manually regulate the pressure to the serving keg because regulators only work accurately with some minimum high side pressure. I suppose you could buy and rig fixed/variable overpressure valve but that's getting really high on the DIY meter.

 

[WortMonger]

What about some sort of a pressure switch and actuated valve ran off batteries or something. LOL, I they could sense a lower than set-point deference in pressure and actuate a shot from your CO2. I am looking right now for something simpler, but I am thinking automated injection to a set psi is the only way I would want it, and cheaper....much cheaper than these pressure switches on mcmastercarr I am staring at.

 

[WortMonger]

What about this for filling and compressing the CO2 to 100 psi in the 5# tank?

Light Duty Oilless Air Compressor/Vacuum Pump
Get a portable low-flow compressor and vacuum pump in one unit. Great for operating small air-powered tools, inflating tires, and draining liquid from small tanks. Unit has an oilless design, which means it dispenses air that's 100% oil free for clean operation and low maintenance. It also has a one-stage wobble piston design and is rated for continuous operation. Powered by a direct-drive single-phase motor with thermal overload protection. Includes a 15-ft. rubber air hose, tire chuck, filter, and 6-ft. cord with three-prong plug. Outlet is 1/4" NPT male. UL listed and CSA certified.

This little baby would come in handy for numerous other uses around the house, and as a nice way to vacuum seal my grain storage bins. It says oilless, so I am thinking that is all you need for safety/taste/odor concerns? I would be willing to bet it gets all its compressor air from the vacuum hose and vice versa.

 

[WortMonger]

I am actually wondering how someone could fill their own 5# off of their own 25#? I know paintball places do it all the time. This alone would make me happy and save me a ton of trouble and cost.

 

[Sir Humpsalot]

Nice find wortmonger, but it's about 3x what I was thinking of spending.

 

[WortMonger]

Yeah, me too.

The beer staying at serving pressure is a tough one to think through since the regulator won't work at such low back pressures.

 

[WortMonger]

Ohhh, I may have an even smaller solution to my problems (well if I continue buying CO2 in bulk). Check out the refill stuff.

 

[WortMonger]

OK, how bout this for lower back pressure CO2 regulation.

http://cgi.ebay.com/Miniature-Secondary-CO2-Regulator-for-beer-paintbrush_W0QQitemZ150195446351QQihZ005QQcategoryZ38172QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

 

[Bobby_M]

Keep in mind you'll have to collect your CO2 in a collapsable container like a huge balloon. Why? Well, if you collect it in a 1/2barrel keg, there would be no way to collect all the CO2 into the vaccum line of the compressor unless it could pull a vaccum equal to the output pressure (no way).

 

[Sir Humpsalot]

I was about to say mini airbrush things seem like a good fit...

 

[Sir Humpsalot]

Keep in mind you'll have to collect your CO2 in a collapsable container like a huge balloon. Why? Well, if you collect it in a 1/2barrel keg, there would be no way to collect all the CO2 into the vaccum line of the compressor unless it could pull a vaccum equal to the output pressure (no way).

see my post about the double carboy setup. Use water/starsan as a medium for "expanding and collapsing" the volume of a rigid system, for example, one using carboys.

 

[WortMonger]

Ahh haa!! See that is good to know. I was hoping everything after the spunding valve wouldn't have to be controlled, just collected.

 

[Sir Humpsalot]

In fact, if there were a way of preventing CO2 from dissolving in water, we could use about a gallon of water in a tube with a nearly 2-inch cross-section, about 10 feet high, to create 8 pounds of pressure on the co2 in a carboy... (231 cu inches in a gallon, a gallon of water equals 8.33 lbs) I didn't actually do any measurements or math, but that's my rough guess of what it would take...

You know what though? I'm tired of looking for a simple hydraulic device... I'm thinking I could make one... I'm going to go search the net for parts....

 

[Philip1993]

8# of h2o would require a one square inch piston (1.13in diameter) to create 8psi. A 2 inch diameter piston would would generate a mere 2.65psi.

 

[Sir Humpsalot]

Ok, forget the parts list, it's going to be quite a search, but basically, here's what you need.

Two pistons housed in a cylinder, each with a port. On one side, you have, for example, a 3 square inch piston. On the other side, you have a one square inch piston.

You use a low pressure pump, like one from a spray gun, into the 3 inch diameter piston. at 50 psi, you have 150 pounds of force.

Now, on the 1 inch side, you introduce CO2. where 1/3 of the volume gets squeezed up to 150 psi. Open the valve on the tank, put the gas in, close the valve, and release the pressure.

Now, just find a way to automate this procedure safely....

 

[david_42]

You could get around many of the problems by using a high pressure portable air compressor & putting it inside of your collection balloon. (Maybe one of those balloons used for flying meteorological instruments.) You could control the compressor with a micro-switch triggered by the balloon collapsing.

 

[Nwcw2001]

I am actually wondering how someone could fill their own 5# off of their own 25#? I know paintball places do it all the time. This alone would make me happy and save me a ton of trouble and cost.

Yes that is possible. At the brewery I worked at before I move to Colorado, I needed to fill my buddy's 25# CO2 tank after emptying it after 2 years of use. The Brewer had what he called a "pigtail" and it was a tube with a screw end, like on your regulator, on each end. Hook up both tanks and turn the gas on the full one, open the empty one and it PARTIALLY fills. At this point you turn off the valves and disconnect the partial tank. Open the valve on the partial to drain the tank quickly (but not full bore or the gas inside will turn to dry ice) and chill it down, because a warm tank will not fill all the way. Weigh the empty tank to find out how much the tank weighs. Reconnect the tanks and repeat the filling direction, when the hissing stops it will be full. Now weigh the tank to ensure it is holding the correct poundage! IF it is more than the tank should be (ie: 6#'s in a 5# tank) bleed it off or you will blow the safety valve.

 

[Sir Humpsalot]

You could get around many of the problems by using a high pressure portable air compressor & putting it inside of your collection balloon. (Maybe one of those balloons used for flying meteorological instruments.) You could control the compressor with a micro-switch triggered by the balloon collapsing.

True.. but I would prefer one that's pneumatic-based, rather than electrically based. I am afraid of what would happen when using an electrical device in an oxygen-free environment. I'm not saying whether or not it's dangerous, but it's just something I haven't ever thought about and I'm rather unsure of where to start...

 

[Yuri_Rage]

I am afraid of what would happen when using an electrical device in an oxygen-free environment.

There's really nothing to fear. Fire needs oxygen. CO2 puts fires out. Electrical devices don't need oxygen to run. I think you're good to go!

 

[Philip1993]

I am actually wondering how someone could fill their own 5# off of their own 25#? I know paintball places do it all the time. This alone would make me happy and save me a ton of trouble and cost.

I have a simple adapter that I use to fill 1# propane cylinders off a 30# tank. And my rocket buddies fill N2O cylinders of a bulk tank. In both cases, the supply is inverted to flow liquid into the destination. Stop filling when the target weighs the proper weight. AS already indicated, overfilling can result in the burst disk rupturing when the tank reaches ambient temps.

 

[WortMonger]

Would a single piston and "one side closed" cylinder work? What if the cylinder was plumbed with two one-way valves (one only introducing CO2 from your collection device, and the other leading to the target CO2 tanks plumbing and connections), and a manual relief valve to purge the system the first time. The piston and closed-off cylinder could be attached to a car jack by surrounding them both with a heavier gauge metal welding both permanantly together opposing each others force. How would that work for filling the tank over a couple of times jacking?

Just found this, I need a air compressor!!!

 

[macs]

True.. but I would prefer one that's pneumatic-based, rather than electrically based. I am afraid of what would happen when using an electrical device in an oxygen-free environment. I'm not saying whether or not it's dangerous, but it's just something I haven't ever thought about and I'm rather unsure of where to start...

I arc weld with CO2 as the shielding gas. If it's fairly pure CO2 there is no danger.

 

[macs]

Would a single piston and "one side closed" cylinder work? What if the cylinder was plumbed with two one-way valves (one only introducing CO2 from your collection device, and the other leading to the target CO2 tanks plumbing and connections), and a manual relief valve to purge the system the first time. The piston and closed-off cylinder could be attached to a car jack by surrounding them both with a heavier gauge metal welding both permanantly together opposing each others force. How would that work for filling the tank over a couple of times jacking?

Just found this, I need a air compressor!!!

I like that huge guage on that small tank!! What pressure scale does it cover??