Carbon Dioxide (CO 2 )
What is CO2?
Carbon dioxide is the combination of two atoms of oxygen joined with a single atom of carbon. Its chemical formula CO 2 , is almost as well-known as that of water, H 2 O, and it is frequently referred to by its formula rather than its name.
In nature’s chain of life, the mutual dependence of plant and animal life is maintained through the link of carbon dioxide. Every time we breathe we release this gas, which plants need for life. Through the process of photosynthesis, the plants separate the carbon from the oxygen. In turn, plants release the pure oxygen, which we need to survive. We reverse the process, and by combining the oxygen with carbon from the foods we eat, produce carbon dioxide again.
CO2 is a colourless, inert gas approximately 1 ½ times heavier than air and 0.03 % is present in the earth’s atmosphere. It is odorless, has a sweet biting taste (soda water) and is highly stable (difficult to separate).
It is produced in varying amounts by the common process of combustion of fuels high in carbon content. The most common source of fuel for combustion is oil which, when mixed with the correct proportion of air, burns to produce around 15 % CO 2 in the flue gases of a CO 2 plant. After combustion has taken place, the CO 2 can be separated from the flue gases and, through a simple process, made available for the many commercial purposes to which it can be applied.
CO2 can exist in three forms:
- in gaseous form: for the beverage and food industries
- in liquid form: in a storage tank under pressure
- in solid form: called dry ice (for cooling, blasting etc.)