Combustion and Types of Combustion
Burning or combustion is an exothermic redox chemical reaction between a reductant or fuel and an oxidant that creates oxidised, mostly gaseous products in the form of heat and light at a high temperature.
Types of Combustion:
Complete Combustion:
The reactant burns in oxygen and produces fewer products during complete combustion. For intsance, when petroleum products are burned in the presence of oxygen, the reaction produces mainly carbon dioxide and water. The products of different elements burned are mostly common chemical oxides. Carbon gives off carbon dioxide, phosphorus gives off phosphorus oxide, zinc gives off zinc oxide, while copper gives off copper oxide.
Incomplete Combustion:
If there is not enough oxygen, this combustion occurs, allowing the fuel to react, creating carbon monoxide and soot. It is also known as pyrolysis. This combustion is similar to complete combustion in that it generates water and produces carbon and carbon monoxide instead of carbon dioxide. Products of pyrolysis remain unburned in this form of combustion, contaminating the resulting smoke with toxic gases.
Spontaneous Combustion:
It’s a sort of combustion that starts with self-healing, then progresses to thermal runaway, and lastly ignites. Phosphorous, for example, ignites on its own at ambient temperature without the use of heat.
Rapid Combustion:
Rapid combustion, also known as fire, is a sort of reaction that produces a lot of heat and light and typically results in a flame. Internal combustion engines and thermobaric weaponry are examples of machinery that involve this reaction. This type of combustion is also called as explosion combustion.
Turbulent combustion:
This is a type of combustion that produces a turbulent flame. It is used in industrial applications because the turbulence aids in the mixing of fuels and oxidizers.
Micro-combustion:
Micro combustion refers to combustion processes that take place in extremely small amounts. Also, the high surface-to-volume ratio increases heat loss.
Smoldering:
This is a low-temperature, sluggish, flameless combustion caused by the heat generated when the surface of the fuel is directly in contact with oxygen. In most cases, it’s an incomplete combustion reaction. Coal, cellulose, cotton, tobacco, wood, foams, and other solid materials undergo smoldering combustion.
Types of Combustion Fuels
Fuels of combustion are substances or materials that undergo combustion. Natural gas, kerosene, diesel, charcoal, and other fuels are some of the most common examples.
Gaseous fuels:
Diffusion flame, premixed flame, autoignitive reaction, or detonation are the four forms of burning that are used to burn gaseous fuels. The degree to which the fuel and oxidizer are blended, as well as the pressure used prior to pre-heating, determine the types of burning.
Liquid fuels:
Liquid fuels are flammable molecules that can be utilised to generate mechanical energy. They take on the shape of the container they are in. Liquid fuel combustion occurs in the gas phase. The fumes, not the fluid, of a liquid fuel is flammable, which is why a liquid only catches fire above a specific temperature.
Solid fuels:
Solid fuels are solid materials that are burned to generate energy and heat. Wood, charcoal, wheat, and corn, as well as pellets derived from wood and other grains, are examples of solid fuels. For thousands of years, humans have used solid fuel to make fire.