SpudFiles

I don't have any idea why there would be more benifits from gass stored as a liquid. It is the same ammount of gass compressed into the same volume just as a liquid. Well maybe if it was different types of gasses or somthing. Any pneumatic experts wan't to post your thoughts?

There's a saving on space for the same mass of propellant.

...and that's about it.

Worthwhile for low gas consumption launchers and where performance is secondary to portability.

Because a downside is that allowing large quantities to evaporate quickly is that the gas comes out pretty dam cold.

there are benefits to having liquid gas.... but the drawback is getting liquid gas

...well a decent gas anyway, CO2 in paintball bottles is liquid alot of the time especially in the winter.... and propane can be a liquid too i do believe... but air....

High density is the big plus. You can get alot of shots out of a small volume.
Freezing up is the downside (vaporisation takes away ALOT of thermal energy)

Another thing I do not like from CO2 is the higher molecular weight -> lower speed of sound -> limitation of power on high performance guns.

The idea is that as soon as you increase the volume of a given vessel, the pressure will automatically decrease (provided all other variables such as temperature/# of molecules remains constant). So you basically will be reducing the power of your [insert pneumatic toy] here with every shot.

Liquifying a gas prevents this, since the liquid will vapourize to compensate for the pressure deficiency.

You haven't really given a context but in industry....

...If you want to move a large quantity of gas from PointA to PointB, you pretty much *HAVE* to liquify.

Take oxygen. You want to move a few tons of it. If you take it at atomspheric you need a train to move it. If you compress it down to a high density.... Now it's small enough to fit on a truck, but the tank that can hold oxygen as a gas compressed that highly? Hey, that tank is probably gonna weigh about 50 tons all by itself.

What do you do?

Refrigerate!

With liquid oxygen I now have a dense product that can be held in a physically small space AND it can be held at atmospheric pressure. Instead of a 50 ton pressure vessel, now all I need is an insulated tank. Easy!

Larger amounts (mol) of liquid gas can be stored in a given space at a lower pressure; I believe most gases of this type (such as CO2) would vaporize once you opened your release valve, theoretically providing more power than air.
However, like everyone said, you'd need a special kind of input and release valve, otherwise they would just freeze, resulting in a possibly catastrophic situation.