Though kerosene and diesel oil are both created during the process of refining crude oil, there are many differences that separate the two types of fuel. These differences directly lead to the ways in which the two fuels are used.
Kerosene was first produced for usage in lamps by Abbasid Caliphate in 850AD and has been used ever since. Diesel fuel was not scientifically documented or widely used until the invention of the diesel engine in 1892 by Rudolf Christian Karl Diesel.
Diesel fuel has a rigid molecular structure consisting of 16 carbon atoms and 34 hydrogen atoms. Kerosene, on the other hand, does not have a set molecular structure and is rather a compilation of hydrocarbon chains that are made up of between 12 and 15 carbon atoms.
The oil refining process is performed by heating and distilling crude oil. During this process, kerosene is produced first at a temperature of between 150 degrees C and 275 degrees C (302 and 527 degrees F), while diesel fuel is made later in the process at a temperature of between 200 degrees C and 350 degrees C (392 and 662 degrees F).
Diesel oil is highly regulated and expensive to refine and produce. Its sale is typically taxed, and its prices are volatile and based on market conditions. Kerosene's prices are typically lower and more steady.
Kerosene is used in producing heat and light, as an ingredient in jet fuel and as a fuel for cooking in developing countries. Diesel fuel is used in a wide variety of vehicles, including trucks, trains and some automobiles. It can also be used to make electricity using diesel-powered generators and as a heating oil.