Science Lists

Our Lives Depend Upon It

Too much of a good thing in the wrong place can be a problem. At the moment there is a little too much CO2 in the upper atmosphere and that is having an undesired effect, heating the planet and changing the climate. However we can’t live without it.
We are a carbon based life form, all life on earth is. Without carbon, life as we know it would not exist. The human body is 18% carbon; in plants the percentage is much higher. And this carbon comes from CO2 in the air which plants use for photosynthesis, converting it to sugars, starches and other organic molecules. Humans and animals feed on the plants, or on other animals that consume those plants, and incorporate the carbon into their bodies.

Being an innovative carbon based life form we have found a variety of other uses for CO2, many of them based on a rather unusual property of the gas. At normal atmospheric pressure CO2 cannot exist as a liquid. Solid CO2 (formed at -78.5°C) changes immediately from a solid to a gas without becoming a liquid. Known as dry ice, it is extensively used for refrigeration. It is colder and lighter than ice; lasts longer and doesn’t leave a mess when it evaporates. Dry ice is widely used to transport fresh fruit, vegetables and flowers; and to transport and store biological specimens and blood platelets. Check this out if you are looking for the best cleaning services. 

The intense cold of dry ice shrinks metal and can be used to removes dents. It removes old tiles without damage by breaking the bonding agent. Other uses include snap freezing fresh fruit, removing warts and producing spectacular fog at parties.

More recently dry ice has been used in factory cleaning. Tiny particles of dry ice are blasted onto the dirty surface. The cold makes the deposits brittle and they crack allowing the dry ice to penetrate. As the dry ice turns to gas it expands with explosive force, lifting the deposits from the surface. This technique can be used to remove hazardous materials such as lead paint and has a big advantage over other methods as there is no residue from the dry ice. The only hazardous material to be disposed of is the paint itself. The same technique can be used to remove mould; to clean fire damaged buildings; in hospital cleaning to remove deposits from medical equipment without damaging it, and to safely clean electrical and electronic systems. CO2 liquefied under pressure is also sometimes used in dry cleaning and window cleaning Perth.

CO2 already has a wide range of uses. But now that we have an excess which is causing problems for the planet, people are actively looking for new ways to use it, to take it out of the atmosphere and immobilise it. It will be interesting to see if they can come up with something as good as a tree.

Back to Top