Natural sources of hydrocarbons. Oil refining Natural sources of hydrocarbons hard coal
The most important natural sources of hydrocarbons are oil , natural gas And coal . They form rich deposits in various regions of the Earth.
Previously, extracted natural products were used exclusively as fuel. At present, methods for their processing have been developed and are widely used, which make it possible to isolate valuable hydrocarbons, which are used both as high-quality fuel and as raw materials for various organic synthesis. Processing of natural sources of raw materials petrochemical industry . Let us analyze the main methods of processing natural hydrocarbons.
The most valuable source of natural raw materials - oil . It is an oily liquid of dark brown or black color with a characteristic odor, practically insoluble in water. The density of oil is 0.73–0.97 g/cm3. Oil is a complex mixture of various liquid hydrocarbons in which gaseous and solid hydrocarbons are dissolved, and the composition of oil from different fields may differ. Alkanes, cycloalkanes, aromatic hydrocarbons, as well as oxygen-, sulfur- and nitrogen-containing organic compounds can be present in oil in various proportions.
Crude oil is practically not used, but is processed.
Distinguish primary oil refining (distillation ), i.e. separating it into fractions with different boiling points, and recycling (cracking ), during which the structure of hydrocarbons is changed
dov included in its composition.
Primary oil refining It is based on the fact that the boiling point of hydrocarbons is the greater, the greater their molar mass. Oil contains compounds with boiling points from 30 to 550°C. As a result of distillation, oil is separated into fractions boiling at different temperatures and containing mixtures of hydrocarbons with different molar masses. These fractions find a variety of uses (see table 10.2).
Table 10.2. Products of primary oil refining.
| Fraction | Boiling point, °C | Composition | Application |
| Liquefied gas | <30 | Hydrocarbons С 3 -С 4 | Gaseous fuels, raw materials for the chemical industry |
| Petrol | 40-200 | Hydrocarbons C 5 - C 9 | Aviation and automotive fuel, solvent |
| Naphtha | 150-250 | Hydrocarbons C 9 - C 12 | Diesel engine fuel, solvent |
| Kerosene | 180-300 | Hydrocarbons С 9 -С 16 | Diesel engine fuel, household fuel, lighting fuel |
| gas oil | 250-360 | Hydrocarbons С 12 -С 35 | Diesel fuel, feedstock for catalytic cracking |
| fuel oil | > 360 | Higher hydrocarbons, O-, N-, S-, Me-containing substances | Fuel for boiler plants and industrial furnaces, feedstock for further distillation |
The share of fuel oil accounts for about half of the mass of oil. Therefore, it is also subjected to thermal processing. To prevent decomposition, the fuel oil is distilled under reduced pressure. In this case, several fractions are obtained: liquid hydrocarbons, which are used as lubricating oils ; mixture of liquid and solid hydrocarbons - petrolatum used in the preparation of ointments; a mixture of solid hydrocarbons - paraffin , going to the production of shoe polish, candles, matches and pencils, as well as for the impregnation of wood; non-volatile residue tar used to produce road, construction and roofing bitumen.
Oil refining includes chemical reactions that change the composition and chemical structure of hydrocarbons. Its variety
ty - thermal cracking, catalytic cracking, catalytic reforming.
Thermal cracking usually subjected to fuel oil and other heavy oil fractions. At a temperature of 450–550°C and a pressure of 2–7 MPa, the free radical mechanism splits hydrocarbon molecules into fragments with a smaller number of carbon atoms, and saturated and unsaturated compounds are formed:
C 16 N 34 ¾® C 8 N 18 + C 8 N 16
C 8 H 18 ¾®C 4 H 10 +C 4 H 8
In this way, automobile gasoline is obtained.
catalytic cracking carried out in the presence of catalysts (usually aluminosilicates) at atmospheric pressure and a temperature of 550 - 600°C. At the same time, aviation gasoline is obtained from kerosene and gas oil fractions of oil.
The splitting of hydrocarbons in the presence of aluminosilicates proceeds according to the ionic mechanism and is accompanied by isomerization, i.e. the formation of a mixture of saturated and unsaturated hydrocarbons with a branched carbon skeleton, for example:
CH 3 CH 3 CH 3 CH 3 CH 3
cat., t||
C 16 H 34 ¾¾® CH 3 -C -C-CH 3 + CH 3 -C \u003d C - CH-CH 3
catalytic reforming carried out at a temperature of 470-540°C and a pressure of 1-5 MPa using platinum or platinum-rhenium catalysts deposited on a base of Al 2 O 3 . Under these conditions, the transformation of paraffins and
petroleum cycloparaffins to aromatic hydrocarbons
cat., t, p
¾¾¾¾® + 3H 2
cat., t, p
C 6 H 14 ¾¾¾¾® + 4H 2
Catalytic processes make it possible to obtain gasoline of improved quality due to the high content of branched and aromatic hydrocarbons in it. The quality of gasoline is characterized by its octane rating. The more the mixture of fuel and air is compressed by the pistons, the greater the power of the engine. However, compression can only be carried out up to a certain limit, above which detonation (explosion) occurs.
gas mixture, causing overheating and premature engine wear. The lowest resistance to detonation in normal paraffins. With a decrease in the chain length, an increase in its branching and the number of double
ny connections, it increases; it is especially high in aromatic carbohydrates.
before giving birth. To assess the knock resistance of various grades of gasoline, they are compared with those for a mixture isooctane And n-heptane with different ratio of components; the octane number is equal to the percentage of isooctane in this mixture. The larger it is, the higher the quality of gasoline. The octane number can also be increased by adding special antiknock agents, for example, tetraethyl lead Pb(C 2 H 5) 4 , however, such gasoline and its combustion products are toxic.
In addition to liquid fuels, lower gaseous hydrocarbons are obtained in catalytic processes, which are then used as raw materials for organic synthesis.
Another important natural source of hydrocarbons, the importance of which is constantly increasing - natural gas. It contains up to 98% by volume of methane, 2–3% by volume. its closest homologues, as well as impurities of hydrogen sulfide, nitrogen, carbon dioxide, noble gases and water. Gases released during oil production ( passing ), contain less methane, but more of its homologues.
Natural gas is used as fuel. In addition, individual saturated hydrocarbons are isolated from it by distillation, as well as synthesis gas , consisting mainly of CO and hydrogen; they are used as raw materials for various organic syntheses.
Mined in large quantities coal - inhomogeneous solid material of black or gray-black color. It is a complex mixture of various macromolecular compounds.
Coal is used as a solid fuel, and is also subjected to coking – dry distillation without air access at 1000-1200°C. As a result of this process are formed: coke , which is a finely divided graphite and is used in metallurgy as a reducing agent; coal tar , which is subjected to distillation and aromatic hydrocarbons (benzene, toluene, xylene, phenol, etc.) are obtained and pitch , going to the preparation of roofing roofing; ammonia water And coke oven gas containing about 60% hydrogen and 25% methane.
Thus, natural sources of hydrocarbons provide
the chemical industry with diverse and relatively cheap raw materials for organic syntheses, which make it possible to obtain numerous organic compounds that are not found in nature, but are necessary for man.
The general scheme for the use of natural raw materials for the main organic and petrochemical synthesis can be represented as follows.
Arenas Syngas Acetylene AlkenesAlkanes
Basic organic and petrochemical synthesis
Control tasks.
1222. What is the difference between primary oil refining and secondary refining?
1223. What compounds determine the high quality of gasoline?
1224. Suggest a method that allows, starting from oil, to obtain ethyl alcohol.
– consists (mainly) of methane and (in smaller quantities) of its closest homologues - ethane, propane, butane, pentane, hexane, etc.; observed in associated petroleum gas, i.e., natural gas that is in nature above oil or dissolved in it under pressure.
Oil
- it is an oily combustible liquid, consisting of alkanes, cycloalkanes, arenes (predominate), as well as oxygen-, nitrogen- and sulfur-containing compounds.
Coal
- solid fuel mineral of organic origin. It contains little graphite a and many complex cyclic compounds, including the elements C, H, O, N and S. There are anthracite (almost anhydrous), coal (-4% moisture) and brown coal (50-60% moisture). By coking coal is converted into hydrocarbons (gaseous, liquid and solid) and coke (rather pure graphite).
Coal coking
Heating coal without air access to 900-1050 ° C leads to its thermal decomposition with the formation of volatile products (coal tar, ammonia water and coke oven gas) and a solid residue - coke.
Main products: coke - 96-98% carbon; coke oven gas - 60% hydrogen, 25% methane, 7% carbon monoxide (II), etc.
By-products: coal tar (benzene, toluene), ammonia (from coke oven gas), etc.
Oil refining by rectification method
The pre-purified oil is subjected to atmospheric (or vacuum) distillation into fractions with certain boiling point ranges in continuous distillation columns.
Main products: light and heavy gasoline, kerosene, gas oil, lubricating oils, fuel oil, tar.
Oil refining by catalytic cracking
Raw materials: high-boiling oil fractions (kerosene, gas oil, etc.)
Auxiliary materials: catalysts (modified aluminosilicates).
The main chemical process: at a temperature of 500-600 ° C and a pressure of 5 10 5 Pa, hydrocarbon molecules are split into smaller molecules, catalytic cracking is accompanied by aromatization, isomerization, alkylation reactions.
Products: mixture of low-boiling hydrocarbons (fuel, feedstock for petrochemicals).
C 16. H 34 → C 8 H 18 + C 8 H 16
C 8 H 18 → C 4 H 10 + C 4 H 8
C 4 H 10 → C 2 H 6 + C 2 H 4
Compounds containing only carbon and hydrogen atoms.
Hydrocarbons are divided into cyclic (carbocyclic compounds) and acyclic.
Cyclic (carbocyclic) compounds are called compounds that include one or more cycles consisting only of carbon atoms (as opposed to heterocyclic compounds containing heteroatoms - nitrogen, sulfur, oxygen, etc.). Carbocyclic compounds, in turn, are divided into aromatic and non-aromatic (alicyclic) compounds.
Acyclic hydrocarbons include organic compounds whose carbon skeleton of molecules is open chains.
These chains can be formed by single bonds (al-kanes), contain one double bond (alkenes), two or more double bonds (dienes or polyenes), one triple bond (alkynes).
As you know, carbon chains are part of most organic substances. Thus, the study of hydrocarbons is of particular importance, since these compounds are the structural basis of other classes of organic compounds.
In addition, hydrocarbons, especially alkanes, are the main natural sources of organic compounds and the basis of the most important industrial and laboratory syntheses (Scheme 1).
You already know that hydrocarbons are the most important feedstock for the chemical industry. In turn, hydrocarbons are quite widespread in nature and can be isolated from various natural sources: oil, associated petroleum and natural gas, coal. Let's consider them in more detail.
Oil- a natural complex mixture of hydrocarbons, mainly linear and branched alkanes, containing from 5 to 50 carbon atoms in molecules, with other organic substances. Its composition significantly depends on the place of its extraction (deposit), it can, in addition to alkanes, contain cycloalkanes and aromatic hydrocarbons.
Gaseous and solid components of oil are dissolved in its liquid components, which determines its state of aggregation. Oil is an oily liquid of dark (from brown to black) color with a characteristic odor, insoluble in water. Its density is less than that of water, therefore, getting into it, oil spreads over the surface, preventing the dissolution of oxygen and other air gases in water. Obviously, getting into natural water bodies, oil causes the death of microorganisms and animals, leading to environmental disasters and even catastrophes. There are bacteria that can use the components of oil as food, converting it into harmless products of their vital activity. It is clear that the use of cultures of these bacteria is the most environmentally safe and promising way to combat oil pollution in the process of its production, transportation and processing.
In nature, oil and associated petroleum gas, which will be discussed below, fill the cavities of the earth's interior. Being a mixture of various substances, oil does not have a constant boiling point. It is clear that each of its components retains its individual physical properties in the mixture, which makes it possible to separate the oil into its components. To do this, it is purified from mechanical impurities, sulfur-containing compounds and subjected to the so-called fractional distillation, or rectification.
Fractional distillation is a physical method for separating a mixture of components with different boiling points.
Distillation is carried out in special installations - distillation columns, in which the cycles of condensation and evaporation of liquid substances contained in oil are repeated (Fig. 9). 
Vapors formed during the boiling of a mixture of substances are enriched with a lighter-boiling (i.e., having a lower temperature) component. These vapors are collected, condensed (cooled to below boiling point) and brought back to a boil. In this case, vapors are formed that are even more enriched with a low-boiling substance. By repeated repetition of these cycles, it is possible to achieve almost complete separation of the substances contained in the mixture.
The distillation column receives oil heated in a tubular furnace to a temperature of 320-350 °C. The distillation column has horizontal partitions with holes - the so-called plates, on which the oil fractions condense. Light-boiling fractions accumulate on the higher ones, high-boiling fractions on the lower ones.
In the process of rectification, oil is divided into the following fractions:
Rectification gases - a mixture of low molecular weight hydrocarbons, mainly propane and butane, with a boiling point of up to 40 ° C;
Gasoline fraction (gasoline) - hydrocarbons of composition from C 5 H 12 to C 11 H 24 (boiling point 40-200 ° C); with a finer separation of this fraction, gasoline (petroleum ether, 40-70 ° C) and gasoline (70-120 ° C) are obtained;
Naphtha fraction - hydrocarbons of composition from C8H18 to C14H30 (boiling point 150-250 ° C);
Kerosene fraction - hydrocarbons of composition from C12H26 to C18H38 (boiling point 180-300 ° C);
Diesel fuel - hydrocarbons of composition from C13H28 to C19H36 (boiling point 200-350 ° C).
Residue of oil distillation - fuel oil- contains hydrocarbons with the number of carbon atoms from 18 to 50. Distillation under reduced pressure from fuel oil produces solar oil (C18H28-C25H52), lubricating oils (C28H58-C38H78), vaseline and paraffin - fusible mixtures of solid hydrocarbons. The solid residue of fuel oil distillation - tar and its processing products - bitumen and asphalt are used for the manufacture of road surfaces.
The products obtained as a result of oil rectification are subjected to chemical processing, which includes a number of complex processes. One of them is the cracking of petroleum products. You already know that fuel oil is separated into components under reduced pressure. This is due to the fact that at atmospheric pressure, its components begin to decompose before reaching the boiling point. This is what underlies cracking.
Cracking - thermal decomposition of petroleum products, leading to the formation of hydrocarbons with a smaller number of carbon atoms in the molecule.
There are several types of cracking: thermal cracking, catalytic cracking, high pressure cracking, reduction cracking.
Thermal cracking consists in the splitting of hydrocarbon molecules with a long carbon chain into shorter ones under the influence of high temperature (470-550 ° C). In the process of this splitting, along with alkanes, alkenes are formed.
In general, this reaction can be written as follows:
C n H 2n+2 -> C n-k H 2(n-k)+2 + C k H 2k
alkane alkane alkene
long chain
The resulting hydrocarbons can be cracked again to form alkanes and alkenes with an even shorter chain of carbon atoms in the molecule: 
During conventional thermal cracking, many low molecular weight gaseous hydrocarbons are formed, which can be used as raw materials for the production of alcohols, carboxylic acids, and high molecular weight compounds (for example, polyethylene).
catalytic cracking occurs in the presence of catalysts, which are used as natural aluminosilicates of the composition
The implementation of cracking using catalysts leads to the formation of hydrocarbons having a branched or closed chain of carbon atoms in the molecule. The content of hydrocarbons of such a structure in motor fuel significantly improves its quality, primarily knock resistance - the octane number of gasoline.
Cracking of petroleum products proceeds at high temperatures, so carbon deposits (soot) are often formed, contaminating the surface of the catalyst, which sharply reduces its activity.
Cleaning the catalyst surface from carbon deposits - its regeneration - is the main condition for the practical implementation of catalytic cracking. The simplest and cheapest way to regenerate a catalyst is its roasting, during which carbon deposits are oxidized by atmospheric oxygen. Gaseous oxidation products (mainly carbon dioxide and sulfur dioxide) are removed from the catalyst surface.
Catalytic cracking is a heterogeneous process involving solid (catalyst) and gaseous (hydrocarbon vapor) substances. It is obvious that the regeneration of the catalyst - the interaction of solid deposits with atmospheric oxygen - is also a heterogeneous process.
heterogeneous reactions(gas - solid) flow faster as the surface area of the solid increases. Therefore, the catalyst is crushed, and its regeneration and cracking of hydrocarbons are carried out in a "fluidized bed", familiar to you from the production of sulfuric acid.
The cracking feedstock, such as gas oil, enters the conical reactor. The lower part of the reactor has a smaller diameter, so the feed vapor flow rate is very high. The gas moving at high speed captures the catalyst particles and carries them to the upper part of the reactor, where, due to the increase in its diameter, the flow rate decreases. Under the action of gravity, the catalyst particles fall into the lower, narrower part of the reactor, from where they are again carried upwards. Thus, each grain of the catalyst is in constant motion and is washed from all sides by a gaseous reagent. 
Some catalyst grains enter the outer, wider part of the reactor and, without encountering gas flow resistance, sink to the lower part, where they are picked up by the gas flow and carried away to the regenerator. There, too, in the "fluidized bed" mode, the catalyst is burned and returned to the reactor.
Thus, the catalyst circulates between the reactor and the regenerator, and the gaseous products of cracking and roasting are removed from them.
The use of cracking catalysts makes it possible to slightly increase the reaction rate, reduce its temperature, and improve the quality of cracked products.
The obtained hydrocarbons of the gasoline fraction mainly have a linear structure, which leads to a low knock resistance of the obtained gasoline.
We will consider the concept of “knock resistance” later, for now we only note that hydrocarbons with branched molecules have a much greater detonation resistance. It is possible to increase the proportion of isomeric branched hydrocarbons in the mixture formed during cracking by adding isomerization catalysts to the system.
Oil fields contain, as a rule, large accumulations of the so-called associated petroleum gas, which collects above the oil in the earth's crust and partially dissolves in it under the pressure of the overlying rocks. Like oil, associated petroleum gas is a valuable natural source of hydrocarbons. It contains mainly alkanes, which have from 1 to 6 carbon atoms in their molecules. Obviously, the composition of associated petroleum gas is much poorer than oil. However, despite this, it is also widely used both as a fuel and as a raw material for the chemical industry. Until a few decades ago, in most oil fields, associated petroleum gas was burned as a useless addition to oil. At present, for example, in Surgut, Russia's richest oil pantry, the world's cheapest electricity is generated using associated petroleum gas as fuel.
As already noted, associated petroleum gas is richer in composition in various hydrocarbons than natural gas. Dividing them into fractions, they get:
Natural gasoline - a highly volatile mixture consisting mainly of lentane and hexane;
Propane-butane mixture, consisting, as the name implies, of propane and butane and easily turns into a liquid state when pressure increases;
Dry gas - a mixture containing mainly methane and ethane.
Natural gasoline, being a mixture of volatile components with a small molecular weight, evaporates well even at low temperatures. This makes it possible to use gas gasoline as a fuel for internal combustion engines in the Far North and as an additive to motor fuel, which makes it easier to start engines in winter conditions.
A propane-butane mixture in the form of liquefied gas is used as household fuel (gas cylinders familiar to you in the country) and for filling lighters. The gradual transition of road transport to liquefied gas is one of the main ways to overcome the global fuel crisis and solve environmental problems.
Dry gas, close in composition to natural gas, is also widely used as a fuel.
However, the use of associated petroleum gas and its components as a fuel is far from the most promising way to use it.
It is much more efficient to use associated petroleum gas components as feedstock for chemical production. Hydrogen, acetylene, unsaturated and aromatic hydrocarbons and their derivatives are obtained from alkanes, which are part of associated petroleum gas.
Gaseous hydrocarbons can not only accompany oil in the earth's crust, but also form independent accumulations - natural gas deposits.
Natural gas
- a mixture of gaseous saturated hydrocarbons with a small molecular weight. The main component of natural gas is methane, the share of which, depending on the field, ranges from 75 to 99% by volume. In addition to methane, natural gas contains ethane, propane, butane and isobutane, as well as nitrogen and carbon dioxide.
Like associated petroleum gas, natural gas is used both as a fuel and as a raw material for the production of various organic and inorganic substances. You already know that hydrogen, acetylene and methyl alcohol, formaldehyde and formic acid, and many other organic substances are obtained from methane, the main component of natural gas. As a fuel, natural gas is used in power plants, in boiler systems for water heating of residential buildings and industrial buildings, in blast furnace and open-hearth production. Striking a match and lighting gas in the kitchen gas stove of a city house, you "start" a chain reaction of oxidation of alkanes, which are part of natural gas. , In addition to oil, natural and associated petroleum gases, coal is a natural source of hydrocarbons. 0n forms powerful layers in the bowels of the earth, its explored reserves significantly exceed those of oil. Like oil, coal contains a large amount of various organic substances. In addition to organic, it also includes inorganic substances, such as water, ammonia, hydrogen sulfide and, of course, carbon itself - coal. One of the main ways of coal processing is coking - calcination without air access. As a result of coking, which is carried out at a temperature of about 1000 ° C, the following are formed:
Coke oven gas, which includes hydrogen, methane, carbon monoxide and carbon dioxide, impurities of ammonia, nitrogen and other gases;
coal tar containing several hundred different organic substances, including benzene and its homologues, phenol and aromatic alcohols, naphthalene and various heterocyclic compounds;
over-tar, or ammonia water, containing, as the name implies, dissolved ammonia, as well as phenol, hydrogen sulfide and other substances;
coke - solid residue of coking, almost pure carbon.
coke used in the production of iron and steel, ammonia - in the production of nitrogen and combined fertilizers, and the importance of organic coking products can hardly be overestimated.
Thus, associated petroleum and natural gases, coal are not only the most valuable sources of hydrocarbons, but also part of the unique pantry of irreplaceable natural resources, the careful and reasonable use of which is a necessary condition for the progressive development of human society.
1. List the main natural sources of hydrocarbons. What organic substances are included in each of them? What do they have in common?
2. Describe the physical properties of oil. Why doesn't it have a constant boiling point?
3. After summarizing the media reports, describe the environmental disasters caused by the oil spill and how to overcome their consequences.
4. What is rectification? What is this process based on? Name the fractions obtained as a result of oil rectification. How do they differ from each other?
5. What is cracking? Give the equations of three reactions corresponding to the cracking of petroleum products.
6. What types of cracking do you know? What do these processes have in common? How do they differ from each other? What is the fundamental difference between different types of cracked products?
7. Why is associated petroleum gas so named? What are its main components and their uses?
8. How does natural gas differ from associated petroleum gas? What do they have in common? Give the equations of combustion reactions of all components of associated petroleum gas known to you.
9. Give the reaction equations that can be used to obtain benzene from natural gas. Specify the conditions for these reactions.
10. What is coking? What are its products and their composition? Give the equations of reactions typical for the products of coal coking known to you.
11. Explain why burning oil, coal and associated petroleum gas is far from being the most rational way to use them.
The main natural sources of hydrocarbons are oil, gas, coal. Most of the substances of organic chemistry are isolated from them. More about this class of organic substances are discussed below.
Composition of minerals
Hydrocarbons are the most extensive class of organic substances. These include acyclic (linear) and cyclic classes of compounds. Allocate saturated (limit) and unsaturated (unsaturated) hydrocarbons.
The saturated hydrocarbons include compounds with single bonds:
- alkanes- line connections;
- cycloalkanes- cyclic substances.
Unsaturated hydrocarbons include substances with multiple bonds:
- alkenes- contain one double bond;
- alkynes- contain one triple bond;
- alkadienes- includes two double bonds.
Separately, a class of arenes or aromatic hydrocarbons containing a benzene ring is distinguished.
Rice. 1. Classification of hydrocarbons.
Gaseous and liquid hydrocarbons are isolated from minerals. The table describes the natural sources of hydrocarbons in more detail.
|
A source |
Kinds |
|
|
Alkanes, cycloalkanes, arenes, oxygen, nitrogen, sulfur compounds |
||
|
Methane with impurities (not more than 5%): propane, butane, carbon dioxide, nitrogen, hydrogen sulfide, water vapor. Natural gas contains more methane than associated gas |
|
|
Carbon, hydrogen, sulfur, nitrogen, oxygen, hydrocarbons |
More than 600 billion m 3 of gas, 500 million tons of oil, and 300 million tons of coal are produced annually in Russia.
Recycling
Minerals are used in a processed form. Hard coal is calcined without access to oxygen (coking process) in order to isolate several fractions:
- coke oven gas- a mixture of methane, carbon oxides (II) and (IV), ammonia, nitrogen;
- coal tar- a mixture of benzene, its homologues, phenol, arenes, heterocyclic compounds;
- ammonia water- a mixture of ammonia, phenol, hydrogen sulfide;
- coke- the end product of coking containing pure carbon.
Rice. 2. Coking.
One of the leading branches of the world industry is oil refining. Oil extracted from the bowels of the earth is called crude. It is being processed. First, mechanical purification from impurities is carried out, then the purified oil is distilled to obtain various fractions. The table describes the main oil fractions.
|
Fraction |
Composition |
What do they get |
|
Gaseous alkanes from methane to butane |
||
|
Petrol |
Alkanes from pentane (C 5 H 12) to undecane (C 11 H 24) |
Gasoline, ethers |
|
Naphtha |
Alkanes from octane (C 8 H 18) to tetradecane (C 14 H 30) |
Naphtha (heavy gasoline) |
|
Kerosene |
||
|
Diesel |
Alkanes from tridecane (C 13 H 28) to nonadecane (C 19 H 36) |
|
|
Alkanes from pentadecane (C 15 H 32) to pentacontane (C 50 H 102) |
Lubricating oils, petroleum jelly, bitumen, paraffin, tar |
Rice. 3. Oil distillation.
Hydrocarbons are used to produce plastics, fibers, medicines. Methane and propane are used as domestic fuels. Coke is used in the production of iron and steel. From ammonia water produce nitric acid, ammonia, fertilizers. Tar is used in construction.
What have we learned?
From the topic of the lesson, we learned from which natural sources hydrocarbons are isolated. Oil, coal, natural and associated gases are used as raw materials for organic compounds. Minerals are purified and divided into fractions, from which substances suitable for production or direct use are obtained. Liquid fuels and oils are produced from oil. Gases contain methane, propane, butane used as domestic fuel. From coal, liquid and solid raw materials are isolated for the production of alloys, fertilizers, and medicines.
Topic quiz
Report Evaluation
Average rating: 4.2. Total ratings received: 289.