Liquid Carbon Dioxide
Name: Jason B.
Why is liquid carbon dioxide used in the beverage
Liquid CO2 can be stored at ambient conditions under moderate pressure
(critical temperature = 31 C; critical pressure = 73 atm). As a result, 44gm
of CO2 (its molecular weight) when evaporated produces 22.4 liters of gas at
STP. In addition, being a liquid it can be pumped around etc. In contrast
solid CO2 (dry ice) must be stored at low temperature and it is a hard
"chunk". So the use of liquid CO2 is just a matter of efficiency -- a way to
store large quantities of CO2 in a form that is easy to handle.
What else would you use? Liquid carbon dioxide can be very conveniently
stored and transported in metal cylinders at normal room temperature.
It's more compact than the gas; in fact, if you compress the gas at constant
room temperature it will eventually condense to the liquid. The solid is
more difficult to work with, because you'd have to keep it cold for storage
and then warm it up for the carbonation process.
Richard E. Barrans Jr., Ph.D.
PG Research Foundation, Darien, Illinois
Liquid carbon dioxide is used in the beverage industry
as a taste enhancer and for a sparkling aura in the
looks of the beverage in question. I hope that this
answers your question.
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Update: June 2012