Ask A Scientist Chemistry Archive

name         Ann W.
status       educator
age          60s

Question -   How is dry ice made?
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Ann W.,

Over 90% of all carbon dioxide is made by steam-reforming of hydrocarbons, and much of 
the time, natural gas is the feedstock.  Carbon dioxide is a gas at room temperature. 
 Below -78 degrees C, it is a solid and is commonly referred to as "dry ice".  Dry ice 
 is manufactured by expanding liquid carbon dioxide to a vapor, and freezing it into a 
 snow like material and sending the material to a press that compacts the product into 
 blocks.  I hope that this answers your question.

Sincerely,

Bob
Trach
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