CO2 Filters

[colin kaminski]

I was wondering if anyone uses CO2 filters? We have a 7bbl brewery and we use bulk gas from Airgas and it was suggested to me that it would be helpful to filter the CO2 since in the US most CO2 is produced by cracking oil.

I hear Budweiser has started requiring their kegs to be despensed with filtered CO2. They are using Domnick Hunter Model# PCO2 MF-5.

Any thoughts?

[Rosie]

Colin,

I've also been told that it is worth filtering the CO2 I use for carbonation and moving beer.

I was just going to use a inline Hepa filter. The one I'm looking at (Whatman 6723-5000) says it does particles >= .3 m and will take up to 4.1 bar (60psi)...downside it looks like it needs to be sterilised, I'll just pressure cook it...sound reasonable?

Anyone else do this?

Cheers,

[Sir Brewsalot]

Well, I for one do nothing of the kind - just use the gas straight out of the tank. My thinking is that it's all post-fermentation, so the risk of contamination is a bit less.

Of course, this doesn't mean that I shouldn't be filtering it. I'm just saying that I have not had specific issues as a result of not doing it.

Cheers,
Scott

[Larry Horwitz]

Paul Filtration sells a throw away unit for about $100 that does a great job (or so they say) I'm going to install it and I'll let you know.

[imabrewer]

Most CO2 in the U.S. is produced from oil and coal burning or it comes directly from CO2 gas reserves underground almost like natural gas. Legally they need to remove all of the carcinogens and other particulates from the CO2 before it can be used for consumption so you don't need to worry about that with your filters. Mostly the filters are there to protect you from any contaminants in the CO2 bottles or from bad filling practices from your supplier. Rust, dirt, teflon tape bits, etc. and possibly some bacteria. You can use any filter rated for gases at the pressure rating you use and I would run with a 0.45 micron filter or smaller (0.2 or HEPA). Your CO2 supplier can help you with buying one, or use Domnick Hunter or Pall, or any other filter manufacturers that have water / gas filters will probably make one too. In addition, you can request medical/pharaceutical grade CO2 which has even less chance of having problems, but is more costly. I had heard at one time (but don't quote me) that normal CO2 is about 99.8% pure but medical CO2 is about 99.99% pure. At any rate, even if your CO2 is good right now the filters will help to keep your carbonation stones from getting plugged up with bits of rust so it is still beneficial.