Oil and natural gases, these unique usefulfossils, are the main sources of hydrocarbons. Crude oil is a complex mixture of hydrocarbons with other compounds. Oil refining provides products that are then used in all industries, energy, agriculture and everyday life.
Crude oil is divided into constituents by simple, fractional and vacuum distillation. The composition of the fractions obtained in this case depends on the composition of the raw crude oil.
Oil processing passes several stages: fractional distillation, reforming, cracking and purification from sulfur.
Fractional distillation is the very firststage of processing, which divides it into fractions: gas, light, medium and fuel oil. Thus, the primary processing of oil can immediately identify the most valuable fractions.
- The gas fraction is unbranched protozoa hydrocarbons: butanes, propane and ethane.
- Gasoline, or light fraction - a mixture of various light hydrocarbons, including branched and unbranched alkanes.
- Fuel oil remains after the distillation of all other, lighter, fractions.
Further processing of oil is carried outcracking method. In this case, splitting of high-molecular compounds of crude oil into smaller, characteristic for low-boiling fractions occurs. This important method of processing allows obtaining an additional amount of low-boiling oil fractions, the requirements for which, especially in gasoline, are exceptionally high.
- In the industry there are several typescracking: catalytic, thermal and reforming. In thermal cracking, high-molecular compounds from heavy oil fractions are broken down into low-molecular compounds under the influence of high temperatures. Oil processing by cracking both thermal and catalytic, gives a mixture of unsaturated and saturated hydrocarbons. On the example of octadecane, the cracking process can be described by the formula:
FROM18H38 -> C9H20 + C9X18
At temperatures up to 1000 ° C, thermal decomposition of high-molecular petroleum products takes place, resulting in the production of lightly alkenes and aromatic hydrocarbons.
- Catalytic cracking takes place at relativelylow temperatures, the catalyst is a mixture of alumina and silica. In this case, a mixture of saturated and unsaturated hydrocarbons is also obtained. Oil refining by this method is used to produce high-quality gasoline.
- Reforming changes the structure of molecules or unites them into larger ones. In the process, low-quality low-molecular fractions of oil are converted, in particular, into high-grade gasoline fractions.
Natural and associated gases are a mixture of methane (up to 90% by volume) and its closest homologues, as well as a small amount of impurities.
The main task of gas processing is the conversion of the limiting hydrocarbons contained in it into unsaturated hydrocarbons, which can later be used in chemical synthesis.
Thus, the processing of oil and gas allowsto receive an extremely large assortment of various petroleum products, from which as a result of chemical synthesis a huge variety of substances used in various sectors of the country's economy is obtained.
