The key difference between complete and incomplete combustion is that complete combustion takes place when there is a constant and enough oxygen supply whereas incomplete combustion takes place when there isn’t enough oxygen supply.
Originally oxidation reactions are the reactions where oxygen gas participates. There, oxygen combines with another molecule, to produce an oxide. In this reaction, oxygen undergoes reduction, and the other substance undergoes oxidation. So basically oxidation reaction is adding oxygen to another substance. Another way to describe oxidation is as loss of hydrogen. There are some occasions where it is hard to describe oxidation as adding oxygen. There are various types of oxidation reactions. Some are happening in the natural environment daily. Burning and combustion are some oxidizing reactions where humans involve.
CONTENTS
1. Overview and Key Difference
2. What is Complete Combustion
3. What is Incomplete Combustion
4. Side by Side Comparison – Complete vs Incomplete Combustion in Tabular Form
5. Summary
What is Complete Combustion?
Combustion or heating is a reaction heat produces via an exothermic reaction. It is an oxidation reaction. For the reaction to take place, it requires fuel and an oxidant. Substances undergoing the combustion are the fuels. Examples include hydrocarbons like petrol, diesel, methane, or hydrogen gas, etc. Usually, the oxidizing agent is oxygen, but some other oxidants such as fluorine can also act as oxidizing agents.
Figure 01: Flame during Complete Combustion
In the reaction, the oxidant oxidizes the fuel. So this is an oxidation reaction. When we use hydrocarbon fuels, the products after complete combustion are usually carbon dioxide and water. In complete combustion, few products forms, and it gives the maximum energy output that the reactant can give. However, for complete combustion to take place, unlimited and constant oxygen supply and optimum temperature are requirements. Hence, complete combustion is not always a favourable reaction.
What is Incomplete Combustion?
When there isn’t enough oxygen, incomplete combustion takes place.
Figure 02: Destruction and Pollution from the Incomplete Combustion
If the combustion had not happened completely, carbon monoxide and other particles released into the atmosphere and can cause a lot of pollution.
What is the Difference Between Complete and Incomplete Combustion?
Complete combustion is in the form of combustion that takes place when there is a constant and enough oxygen supply. Incomplete combustion is the form of combustion that takes place when there isn’t enough oxygen supply. In complete combustion, a limited number of products form while in incomplete combustion, some products may form.
Furthermore, if a hydrocarbon undergoes complete combustion, it produces only carbon dioxide and water while carbon monoxide and carbon particles may form in incomplete combustion. With concern to the energy produced by these two forms of combustion, Complete combustion results in more energy on the contrary, Incomplete combustion results in less energy. Moreover, Complete combustion does not cause environmental pollution. However, incomplete combustion cause environmental pollution.
Summary – Complete vs Incomplete Combustion
Combustion may take place in two types as complete and incomplete combustion. Both are oxidation reactions. The difference between complete and incomplete combustion is that complete combustion takes place when there is a constant and enough oxygen supply whereas incomplete combustion takes place when there isn’t enough oxygen supply.
Reference:
1. “GCSE Bitesize: Combustion.” BBC, BBC. Available here
2. “Combustion.” Wikipedia, Wikimedia Foundation, 12 May 2018. Available here
Image Courtesy:
1.’486575859′ by Paul Kretek (CC BY 2.0) via Flickr
2.’Kuwait burn oilfield crop1’By Jonas Jordan (Public Domain) via Commons Wikimedia