There are few people who do not know about the existence of such a substance as kerosene. It is ubiquitous and has been known for many years. But what, for example, is the boiling point of kerosene? What is its density and viscosity? In the article we will analyze the basic properties of a substance, and also consider the directions of its application.
What is it?
Kerosene is a combustible mixture consisting of liquid hydrocarbons. The boiling point of kerosene varies between 150-250 ° Celsius. It is a clear, colorless (in some cases yellowish) liquid, slightly oily to the touch.
The word itself came from the English. kerosene. In turn, it has Greek roots: κηρός - "wax".
Kerosene is obtained by direct distillation or ratification of oil. Sometimes through recycling. In some cases, the product is hydrotreated.
Substance composition
We figured out the boiling point of kerosene. Now imagine the composition of this product. It is not universal and reference, since it depends on the raw material - oil, its processing method and chemical composition.
So, the composition of kerosene according to GOST:
- Aliphatic saturated hydrocarbons - 20-60% of the total mass.
- Naphthenic hydrocarbons - 20-50%.
- Aromatic bicyclic hydrocarbons - 5-25%.
- Unsaturated hydrocarbons - up to 2%.
- An insignificant content of impurities - sulfur, oxygen or nitrogen.
Now imagine the most important properties of this substance.
Kinematic viscosity
When characterizing kerosene in accordance with GOST, this position will also be relevant. I must say that the viscosity of the hydrocarbons that make up this product changes significantly with a decrease / increase in its temperature. The higher the latter, the lower the viscosity.
This is a very important feature. The viscosity of kerosene has a great influence on a number of operational features of the fuel systems of aircraft, as well as the processes of combustion and mixture formation in the engine.
Thus, the viscosity of kerosene at 20 ° C is 1.2 - 4.5 mm 2 / s.
Density
One of the most important characteristics used in relation to all petroleum products. And if we compare the density of kerosene and water, we will see that the latter will be higher. Here are the specific numbers:
- The density of distilled water at an “ideal” temperature of 3.7 ° C is 1000 kg / m 3 .
- The density of sea water at an "ideal" temperature of 3.7 ° C is 1030 kg / m 3 .
- The density of boiling water at 100 ° C is 958.4 kg / m 3 .
To further compare the density of water and kerosene, we will get acquainted with this characteristic already regarding the oil product. This is 800 kg / m 3 .
It must be said that in the early stages of the development of the oil industry, density was the only characteristic of kerosene. Today, in practice, such a quantity as relative density is most often used. This is a dimensionless indicator equal to the ratio of the true densities of a given oil product and distilled water, taken for comparison at certain temperatures.
So, the density of kerosene at 20 ° C will be from 780 to 850 kg / m 3 .
Flash point
The next characteristic after the boiling point of kerosene is the flash point. This is the parameter by which the degree of fire hazard of a given liquid is determined. Here, the flash point of kerosene will vary from 28 to 60 ° C.
I must say that this characteristic is strictly controlled by standards to prevent gasoline from entering the fuel, which can sharply increase its flammability. The practical determination of the temperature of reactive flashes of kerosene liquid is prescribed by the standards of all states of the world.
Auto ignition temperature
Next in line is another thermal indicator - the ignition temperature of kerosene. Under this characteristic should be understood such ignition of the vapor-air mixture, which leads to combustion. However, ignition of vapors will not always be a sufficient condition for the occurrence of stable combustion of kerosene.
The auto-ignition temperature is the lowest temperature at which oil vapor together with air can ignite without the presence of an ignition source. By the way, it is on such a remarkable property that the functioning of diesel internal combustion engines is based.
Self-ignition of kerosene will occur at a temperature of 300 ° C.
The calorific value of kerosene
Another significant characteristic. The heat of combustion of kerosene is the volume of heat released during the complete combustion of mass (regarding liquid and solid substances) or volumetric (regarding gaseous) units of matter. The value is measured in calories or joules.
Regarding kerosene - 42.9 - 43.1 MJ / kg.
GNP
This abbreviation refers to the height of the smoke-free flame of the oil product. In particular, this is an important characteristic for kerosene KO-25. It determines its ability to burn in a standard wick lamp (with a diameter of the wick 6 mm) with a uniform white flame without the formation of soot or soot.
This is a numerical indicator, measured in millimeters. It must be indicated on the labels of the respective lighting brands of the product. The GNP is directly influenced by the chemical and fractional compositions of kerosene.
Ignition limit
CPV is another significant characteristic of kerosene. This is the name of the ratio of the region of ignition of the vapor of the oil product and the concentration range of this combustible substance, which is evenly distributed in the oxidizing medium (most often in air). Within the boundaries of the latter, the substance can ignite from ignition sources and spread its own combustion throughout the mixture.
The CPV of kerosene will be equal to 1.2-8.0% of the volume of the substance.
Cloud point
The indicator is determined either visually or by optical methods. This is a measurement of the transmission of liquid rays of light.
Studies show that the temperature limit for kerosene here is minus 12 ° Celsius. With a further decrease, the liquid becomes cloudy.
Substance use
Most of all we know fuel kerosene. The oil product is used as jet fuel in rockets and aircraft. This is a well-known fuel used in the firing of porcelain and glass products. Kerosene is also available for household lighting and heating appliances. It is used for metal cutting machines. It is also a solvent (as an example, for applying pesticides), raw materials in the oil refining industry.
Kerosene can actually be used as a substitute for arctic and winter fuel. But in this case, it is not an equivalent alternative - it is necessary to add cetane-raising and anti-wear additives. For multi-fuel engines (based on a diesel engine) it is possible to use pure kerosene, but only for a short time.
In winter, the addition of kerosene in a fraction of 20% to summer diesel will be acceptable in order to lower the pour point of the latter. At the same time, performance will not suffer.
As for the entertainment sphere, it is kerosene that acts as the main fuel during various fire shows (performances with the "participation" of fire). This is facilitated by its excellent absorbency and relatively low combustion temperature. In everyday life, the use of kerosene as a means for removing rust and washing various mechanisms is known.
The main directions of use
In conclusion, we present the most common areas of substance use:
- Aviation kerosene. This is the name of motor fuel for gas turbine engines, which are equipped with various aircraft. These are kerosene fractions of direct distillation of oil. Often they undergo hydrotreating, additives are added to them to improve operational properties. In Russia, five types of such fuel are produced for subsonic aviation - -1, -1, -1, -2 and , and for supersonic - two (-6 and -8).
- Rocket kerosene. Here, this oil product acts as a hydrocarbon environmentally friendly fuel and working fluid of hydraulic machines. Such its use in rocket engines was proposed back in 1914 by Tsiolkovsky. Paired with liquid oxygen, it is used in the lower stages of many launch vehicles.
- Technical kerosene. These are raw materials for the production of aromatic hydrocarbons, ethylene, and propylene. In addition, it is the main fuel for firing porcelain and glass, a solvent for washing parts and mechanisms.
- Lighting kerosene (KO-25, KO-30, KO-20, KO-22). It is used in lighting fixtures, used as fuel for some stoves (kerosene, primus, kerogas). Another use is in heating. This is a solvent, a cleaning agent (widely used to remove residual thermal greases, various coatings), a degreaser.
- Autotractor kerosene. Such an application was characteristic of the dawn of the development of internal combustion engines. The oil product was widely used as fuel for a carburetor and diesel internal combustion engine.
Among non-trivial applications, the following can be distinguished: a folk remedy for getting rid of lice, treatment of pediculosis and diphtheria. In addition, kerosene helped to get rid of bugs by wiping furniture with it.
As you have seen, kerosene immediately determines a set of characteristics. And this seems natural amid its many uses.