Carbon Dioxide

Carbon dioxide is a naturally found oxide of carbon. It is present in the atmosphere in a minute amount (0.04%). It is a colourless and acidic gas having a sharp odour at high concentrations and a sour taste (due to its acidic nature). It is a covalent compound in which the central carbon atom is attached to two oxygen atoms by double bonds. There are several uses of carbon dioxide, majorly for the plant kingdom as they breathe in CO2 and release oxygen (which is then inhaled by us). The gas has industrial uses as well that we will cover in these notes.

Sources and Properties of Carbon Dioxide

Carbon dioxide in the atmosphere comes from the biological process of respiration and combustion. It is produced industrially as well through different processes. 

It can combine many elements, making it an industrially attractive raw material. But, it also shows the property of inertness towards many other materials, which makes it suitable for use in fire extinguishers. In liquid form, it is used in places that require rapid freezing.

Carbon dioxide can douse any flame, i.e., it does not support combustion. It is heavier than oxygen, and thus it can displace oxygen easily. When inhaled in large quantities, it can be life-threatening for the person.

Used To Keep Earth Warm

Carbon dioxide is a greenhouse gas (GHG), i.e. it can trap the heat from the sun and not let it escape the atmosphere. This provides heat to the earth’s surface, which would otherwise remain ice cold, making it impossible for life to exist here. This is one of the most critical uses of carbon dioxide. However, if the concentration of carbon dioxide becomes too high, then excessive heat will be entrapped, leading to global warming. 

For the Survival of Plants

Plants inhale carbon dioxide and exhale oxygen in the presence of sunlight and water via photosynthesis. They cannot grow without carbon dioxide, and if plants were not there, we would not get oxygen. In that way, carbon dioxide, albeit toxic to humans, sustains human life on the planet. 

Chemical equation for photosynthesis

6CO2 + 6H2O + sunlight → 6O2 + C6H12O6 (glucose)

Uses of Carbon Dioxide in Food Industry

When foods are transported from one place to another, they are required to be stored in a cool temperature environment. Liquid or solid carbon dioxide is widely used for that purpose. It acts as a refrigerant to keep the food items cold and fresh.

Gaseous carbon dioxide is mainly used in the beverage industry. When we open a cold drink bottle or can, a lot of bubbles are released. That happens because of the presence of carbon dioxide which is added to beverages to carbonate them. It prevents the growth of microorganisms in the drinks. 

It is also used to decaffeinate coffee. Bakeries use compounds (like sodium carbonate) that release carbon dioxide, which helps to raise the dough and make it soft. It is used in cakes, muffins, cookie dough, etc.

Other Uses of Carbon Dioxide

In animal slaughterhouse: Animals are slaughtered for meat. Carbon dioxide is used to immobilise them before slaughtering, giving better-quality meat. This method is considered “humane” and merciful, allowing for the slaughter of animals in large groups. They are exposed to high concentrations of carbon dioxide gas, and they are killed when they lose consciousness. 

In the textile industry: CO2, being acidic, is used to neutralise basic caustic during textiles manufacturing. It is not harsh on fabrics and easy to handle. It is also used to dye fabrics without water, thus saving tons of water. This technology is already employed by major global brands like Nike and IKEA.

In fire extinguishers: This is one of the major uses of carbon dioxide in everyday life. Carbon dioxide itself does not extinguish the flame, but it cuts the oxygen supply, thus stopping the combustion process. It also has a distinct cooling effect that helps in extinguishing. 

In the oil industry: Carbon dioxide is used to ensure that the maximum amount of oil is extracted from an oil well in the oil industry. It partially dissolves in oil, decreasing its viscosity, thus leading to an easier extraction. 

In Life Jackets and Life Rafts: They are inflated with carbon dioxide to impart the property buoyancy to remain afloat on water. 

In the manufacturing and construction industry, welding is used to protect the weld from surrounding air and moisture. With new technology, this gas can be used to expedite the welding process ten times.  

In winemaking: Dry ice is used to cool down grapes to not spontaneously fermented by wild yeast. It is preferred over regular ice made of water because it does not dilute grapes with water, and thus the flavour is retained.

Conclusion 

The uses of carbon dioxide in everyday life are endless. From food we consume to the life we know, we have CO2 to thank for it. When we are exposed to it in large quantities, we become unconscious, but it has more uses than drawbacks in controlled amounts. It is also used to synthesise various chemical compounds. Plantlife exists because of carbon dioxide only.