Composition and density of kerosene, a method for its production

For a long time, mankind has been trying to find a simple and convenient source of heat, light and fuel. At first, firewood and ordinary straw served as such, later a man learned to extract and use peat. Then humanity made a significant breakthrough in the scientific and technical field in general - and in the fuel sector in particular, starting to use kerosene.

It is a mixture of hydrocarbons boiling at a temperature of 150-250 ° C. This is a transparent, oily, flammable liquid obtained by distilling oil. Depending on the method of processing and chemical composition, kerosene may include saturated hydrocarbons of aliphatic type, naphthenic compounds, bicyclic compounds, various admixtures of oxygen, sulfur or nitrogen elements.

The main stage in the use of domestic kerosene is associated with the invention in 1823 of an oil refinery. And since 1950, when the turboprop and jet aircraft began to develop actively, the production of its other kind, called "aviation kerosene", is being launched. They get both types of kerosene by distilling oil. In the course of primary processing, oil is purified of various impurities and water (it should be noted that the density of kerosene is less than the density of water). Then, the already purified composition is subjected to direct distillation, during which hydrocarbons are boiled off, an oil fraction and a residue are recovered in the form of fuel oil.

On average, the density of kerosene is about 0.78-0.85 g per cubic centimeter, and the flash point varies from 28 to 72 ° C. The density of the combustible liquid used for domestic use is 830 kg per cubic meter, and the temperature of its flash is about 35-40 ° C. These are the most common indicators. The density of kerosene used for lighting in mines and small vessels is 860 kg per cubic meter. The flash point of this type of liquid can be up to 90 ° C. The density of aviation kerosene is not less than 780 kg per cubic meter. Such kerosene is intended for use in flying samples of subsonic aviation.

By kerosene density is meant a value that is determined by the ratio of the mass of this type of fuel to its volume. Determine the density of a given combustible liquid by means of a pycnometer, a device specially designed to determine the density of a variety of liquid and solid bodies.

A pycnometer, a thermostat capable of maintaining a temperature of 20 ° C, a vacuum pump, a vacuum desiccator, a thermometer and kerosene are required for the analysis. The procedure for calculating its density is divided into several basic stages. First, carefully washed and dried pycnometer is weighed. Then it is covered with graphite and weighed again. Then kerosene (up to half the volume) is poured into the flask and placed in a desiccator, where it is kept for about one hour.

At the second stage of the analysis, a pycnometer taken from the desiccator and completely filled with kerosene is placed for one hour in a thermostat. After a certain period of time, the device is removed from the thermostat and its mass is determined. Then, in the same pycnometer, but already well washed and dryed, pour kerosene and do all the same, but only without the addition of graphite. Similar actions are carried out by pouring ordinary distilled water into a pycnometer.

Calculate the density of kerosene according to the following formula: the density of water is multiplied by the difference in the mass of the pycnometer with kerosene and graphite and the weight of the absolutely empty pycnometer, and the result is divided by the difference in the mass of the pycnometer with water and the mass of the empty pycnometer.

The discrepancy allowed between the results of two parallel determinations should not be more than 0.01-0.02 g / cm.