Solid Fuel and Liquid Fuel: Basic Components
Solid fuels are predominantly composed of carbon due to their organic origin. Sources of solid fuel range from wood, coal, charcoal, and crop residues such as wheat straw and husks. Liquid fuels on the other hand have a wide array of hydrocarbon compounds depending on their origin such as petrol, biodiesel, jet fuel, and automotive diesel.
Carbon, due to its multiple covalent bonds, provides a highly oxidized fuel for combustion. The carbon atoms of the solid fuel react with oxygen from the air to produce carbon dioxide and heat, enabling solid fuel to be used for a variety of applications such as cooking and in industry.
Solid fuels are composed of hydrocarbon chains varying in length and complexity, and they can contain other elements such as sulfur, nitrogen and oxygen. These elements influence the type of fuel released when burned, and it is essential to consider their effect on the environment. For example, nitrogen oxides formed during burning present a major pollutant, and the presence of sulfur can produce dangerous and acidic oxides during combustion.
Liquid fuels are predominantly composed of simple molecules, called hydrocarbons, which commonly contain only carbon and hydrogen atoms. They are composed of molecules made up of two or more hydrocarbon units called alkanes. Alkanes have generic formula CnH2n+2, where n is the number of carbon atoms. As the size of the molecule increases, so does the density and calorific value of the fuel.
The fundamental differences between solid and liquid fuels depend on the size, potency, and combustion power of each fuel. While solid fuels produce more energy per unit weight due to their large, complex molecules, liquid fuels on the other hand are more efficient due to their smaller size and increased vaporization rate. Thus, in a given unit of volume, liquid fuel will provide more energy than solid fuel.
The presence and concentration of impurities in liquid fuel can have a significant effect on the fuels quality and combustion efficiency. Depending on the type of distillation process used to purify the fuel, some impurities may remain, impacting the performance of the fuel. For example, the presence of water in jet fuel can lead to corrosion and impact the fuel performance and operational life of the aircraft engine.
In conclusion, solid and liquid fuels have some fundamental differences between them in terms of their composition, energy density, and combustion power. The type, size and potency of each fuel determine its use, and the presence of impurities such as water and sulfur in liquid fuel can have a major impact on the quality and efficiency of the fuel. Therefore, it is essential to consider these factors to ensure the effective, efficient and safe operation of the various applications which require fuel.
