How does carbon monoxide form from fuel combustion?

Carbon monoxide forms from fuel combustion when there is insufficient oxygen for complete combustion.

In a perfect scenario, when a fuel burns in an ample supply of oxygen, the carbon and hydrogen in the fuel fully react with the oxygen to produce carbon dioxide (CO2) and water (H2O). This is known as complete combustion. However, in reality, the conditions are often not perfect. If the oxygen supply is limited, incomplete combustion occurs, leading to the formation of carbon monoxide (CO).

Let's take a closer look at this process. Fuels, such as coal, wood, petrol, and natural gas, are primarily made up of carbon and hydrogen. When these fuels burn, the carbon and hydrogen atoms in the fuel react with the oxygen in the air. In complete combustion, every carbon atom in the fuel combines with two oxygen atoms to form carbon dioxide, and every two hydrogen atoms combine with one oxygen atom to form water.

However, if there isn't enough oxygen available, not all the carbon atoms can find two oxygen atoms to react with. Instead, some carbon atoms end up combining with only one oxygen atom, forming carbon monoxide. This is why carbon monoxide is often produced in poorly ventilated areas where fuel is being burned, such as in a car engine or a poorly ventilated room with a burning stove or fireplace.

Carbon monoxide is a dangerous gas because it is colourless, odourless, and tasteless, making it hard to detect. It is also poisonous to humans and animals. When inhaled, it binds with the haemoglobin in our blood, preventing it from carrying oxygen around the body. This can lead to serious health problems, including death in severe cases. Therefore, it's crucial to ensure proper ventilation when burning fuels to prevent the formation of carbon monoxide.