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Suppose I'm doing a batch process where an intermediate (non-hazardous) reagent is a gas, and I need to produce and temporarily store something on the order of a cubic meter of it to later feed back into a reaction. Assuming the gas can't be condensed at anywhere near STP, isn't there some sort of standard flexible lab gas storage apparatus?

I've been looking for something like a large mylar (or other relatively impermeable) bag with a tube insert I can put on a barb and valve. Either I don't know what this would be called, or it doesn't exist and I should be using something else.

I realize I could try to pump out a large rigid container, but once we're talking about a few cubic meters, and trying to avoid contamination, that seems like a pain compared to a flexible gas bag.

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  • $\begingroup$ I would condense nevertheless, via solid CO2 or liquid nitrogen. Still much simpler to keep cryocooled flask, than handling cubic meter of whatever gas wrapped in plastic. Or compressed into steel cylinder. $\endgroup$
    – ssavec
    Mar 10, 2016 at 17:37
  • $\begingroup$ I haven't sprung for the cost of LN2 yet. I wonder which would be cheaper: LN2 supply and condenser apparatus, or a pump and fittings capable of compressing significantly into a compressed gas cylinder.... $\endgroup$
    – feetwet
    Mar 10, 2016 at 17:49
  • $\begingroup$ Glassware condenser is commonly used for liquefying ammonia and should work for you. LN2 is about 10cents/L, so dirt cheap. Compressing specialty gas is nasty, even if not corrosive. $\endgroup$
    – ssavec
    Mar 10, 2016 at 17:53
  • $\begingroup$ @ssavec - It's paying for a LN2 cylinder that's expensive. My amateur lab isn't near any big institutions where I can just stop by with a small dewar I can stuff in a backpack, so I'd have to have it delivered. Between cylinder rentals and resupplies that's a 4-figure-a-year proposition! $\endgroup$
    – feetwet
    Mar 10, 2016 at 18:11
  • $\begingroup$ I don't know where you are based, but the LN2 suppliers are able to rent a Dewar flask for very acceptable price and at least in Europe, the liquid gas production sites are no more than 50km apart. Hospitals also use liquid gases, etc... $\endgroup$
    – ssavec
    Mar 11, 2016 at 8:40

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It probably depends on local regulations and the properties of the intermediates!

Gas bags might indeed be a viable solution.

In the biogas community, see SolarCities for an example, PVC bags from PUXIN, a chinese supplier, are quite popular.

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