Russian oil refineries. petrochemical industry
An oil refinery is an industrial enterprise whose main function is to refine oil into gasoline, aviation kerosene, fuel oil, diesel fuel, lubricating oils, lubricants, bitumen, petroleum coke, raw materials for petrochemicals. The production cycle of a refinery usually consists of preparation of raw materials, primary distillation of oil and secondary processing of oil fractions: catalytic cracking, catalytic reforming, coking, visbreaking, hydrocracking, hydrotreating and mixing components of finished petroleum products. There are many oil refineries in Russia. Some refineries have been operating for a long time - since the war years, others have been put into operation relatively recently. The Achinsk Oil Refinery turned out to be the youngest plant among the considered enterprises; it has been operating since 2002.
The site compiled a rating of refineries supplying Russian regions with petroleum products.
1. - an oil refinery located in the Bolsheuluysky district Krasnoyarsk Territory. The company was founded on September 5, 2002. Owned by Rosneft.
2. Komsomolsk Oil Refinery is a Russian oil refinery located in the Khabarovsk Territory in the city of Komsomolsk-on-Amur. Also owned by OAO NK Rosneft. Built in 1942. It occupies a significant place in oil refining in the Russian Far East.
3. - Russian oil refinery in the Samara region. Included in the group of OAO NK Rosneft. Year of foundation - 1945.
4. - an oil refining enterprise, located in Moscow, in the Kapotnya district. The plant was commissioned in 1938.
5. - Russian oil refinery in the Samara region. Included in the group of OAO NK Rosneft. The refinery was founded in 1951.
6. Omsk oil refinery is one of the largest oil refineries in Russia. Owned by Gazprom Neft. September 5, 1955 put into operation.
7. - Russian oil refinery. Also known as "Cracking". Part of the TNK-BP group. Located in the city of Saratov. Founded in 1934.
8. - Russian oil refinery in the Samara region. Included in the group of OAO NK Rosneft. Works since 1942.
9. - Russian oil refinery in Krasnodar Territory. The plant is a single production complex with a sea terminal of Rosneft's oil product supply enterprise - OAO NK Rosneft-Tuapsenefteproduct. The main part of the products is exported. It is part of the Rosneft oil company. The year of foundation is 1929.
10. - Russian refinery, a leading Far Eastern manufacturer of motor and boiler fuel. It is part of the NK "Alliance". The enterprise's capacity is 4.35 million tons of oil per year. Founded in 1935.
Tour of the territory of the Moscow Oil Refinery - one of the leading enterprises in the domestic oil refining industry and the largest supplier of petroleum products to the market of the capital region. The plant occupies a leading position in the production of high-octane gasolines and environmentally friendly diesel fuels, and is also among the top five enterprises in terms of capacity utilization for deep oil refining. This first part big story, the second part will be tonight at 20-00. By the way, in the comments I will be glad for your advice, should I write a big post for 100 photos or split it into 2-3?
1. In the mid-1930s, the country's government decided to build an oil refinery near Moscow to supply the capital and the region with motor fuel and bitumen. 
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3. The production complex of the plant includes 23 technological units and produces gasoline grades AI-80; AI-92; AI-95, diesel fuel, jet fuel, bitumen, sulfur, various polymers and so on. 
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7. Installation of primary oil refining "ELOU-AVT-6". It performs atmospheric-vacuum distillation of crude oil and is designed to separate oil into its constituent parts according to their boiling points in order to obtain commercial petroleum products or their components. 
8. During atmospheric distillation, oil is heated to a temperature of 360-370 ° C, at which the boiling fractions are distilled off, and fuel oil remains in the residue. Various types of fuels are obtained from petroleum fractions (gasoline, fuels for jet and diesel engines), raw materials for petrochemical synthesis (benzene, ethylbenzene, xylenes, ethylene, propylene, butadiene), solvents, and more.
9. Vacuum column - the heart of the installation. Further distillation of fuel oil is carried out under vacuum. The resulting material is used as a raw material for the production of oils, paraffin, bitumen, for cracking, or can be used as a liquid boiler fuel. The residue (concentrate, tar) after oxidation can be used as road and construction bitumen or as a component of boiler fuel. 
10. Cylindrical heat exchangers. 
11. Most oil refining processes take place at high temperatures and heat exchangers are used to heat and cool the product.
12. Gate valves. 
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14. Various product pipelines leading to heat exchangers. 
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17. The productivity of such an installation is 6 million tons of oil per year. 
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20. A significant increase in the consumption of petroleum products and increasingly stringent requirements for their quality have led to the need for the so-called secondary processing of oil. 
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22. As a result of recycling, oil is used to produce raw materials for the production of critical products: synthetic rubbers and fibers, plastics, surfactants, detergents, plasticizers, additives, dyes and many others. 
23. Installation of catalytic cracking G-43-107. Catalytic cracking is one of the most important processes that provide deep processing of oil in order to obtain high-octane gasoline. 
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26. Combined plant for the production of MTBE (methyl tertiary butyl ether). 
27. Combined unit TAME (tert amyl ethyl ether). 
28. The work of MTBE and TAME allows the plant to produce high-octane motor gasolines within the framework of the program developed by the Moscow Government to reduce the harmful impact of motor vehicles on the environmental situation in Moscow. 
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34. It is impossible for an unprepared person to understand the complex system of pipes, compressors and valves. 
35. It is impossible for an unprepared person to understand the complex system of pipes, compressors and valves. 
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37. One of the points of management and control over the operation of oil refineries. 
38. This is what the monitors of the plant employees look like. 
Click on the photo to view in large size.
39. Installation of catalytic reforming L-35-11/300. With its help, commercial unleaded gasolines AI-92ek and AI-95ek are produced with improved environmental properties that meet European standards for Euro-3 emissions. 
40. The same installation at night. 
41. By order of the Moscow government, in 1993, the construction of the first polypropylene production complex in Russia with a capacity of 100 thousand tons per year began. 
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43. The technological process for obtaining granulated polypropylene is a closed cycle process using waste-free technology and is fully automated at all stages. 
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46. Polypropylene is intended for the production of molded, extruded, blown products: pipes, fittings, sheets, tapes, films, packaging and non-woven materials, fibers, monofilament, film threads and other technical, household and medical products. 
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48. On the left - catalytic cracking unit G-43-107, and on the right - polypropylene granulation. 
49. Today at 20-00 we will show the second part of the tour of the Moscow Refinery, in which we will tell you about: storage of petroleum products, a refinery flare, automobile and railway terminals for the shipment of gasoline, a bitumen production unit and more. 
All photographs in this report belong to photo agency "28-300", for questions about the use of images, as well as photo shoots, write to e-mail [email protected]
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Moscow oil refinery. Part 1.
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A refinery is an industrial enterprise that refines oil.
Oil refinery - an industrial enterprise for the processing of oil and oil products
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Oil refinery (Oil Refinery) is, the definition
An oil refinery is industrial enterprise
An oil refinery is industrial enterprise, the main function of which is the processing of oil into gasoline, aviation kerosene, fuel oil, diesel fuel, lubricating oils, lubricants, bitumen, petroleum coke, petrochemical raw materials. The production cycle of a refinery usually consists of preparation of raw materials, primary distillation of oil and secondary processing of oil fractions: catalytic cracking, catalytic reforming, coking, visbreaking, hydrocracking, hydrotreating and mixing components of finished petroleum products.
The main types of refinery products today are gasoline, diesel fuel, kerosene, fuel oil.
Oil refineries (refineries) are a set of oil processing units, as well as auxiliary and maintenance services that ensure the normal functioning of the enterprise and the production of petroleum products. The refineries produce petroleum products and raw materials for petrochemicals, and in recent years also consumer goods. The main characteristics of the refinery are: refining capacity, product range and refining depth.
Processing power. Modern oil refineries are characterized by high capacity of both the enterprise as a whole (calculated in millions of tons per year) and technological processes. The capacity of a refinery depends on many factors, primarily on the need for petroleum products in the economic area of their consumption, the availability of raw materials and energy resources, the distance of transportation and the proximity of neighboring similar enterprises. Along with plants processing 5-15 million tons of oil per year, there are giant plants processing 20-25 million tons per year, and small plants processing 3-5 million tons per year.
Assortment of produced petroleum products. The range of produced petroleum products, as a rule, includes about a hundred items. In accordance with the products produced, refineries are usually classified into the following groups: fuel-profile refineries, fuel-oil refineries, fuel-petrochemical refineries (petrochemical plants), fuel-oil-petrochemical refineries. Refineries of the fuel profile are the most widespread, since motor fuels account for the largest percentage of consumption. Complex processing of petroleum feedstock (that is, fuel-oil-petrochemical) is more efficient than highly specialized processing, for example, purely fuel.
Characteristics of oil refineries
Oil refineries are characterized by the variant of oil refining and its depth. At the refinery design stage, the second group of indicators determines the choice of certain technologies for obtaining the corresponding marketable products. Oil refining options: fuel, fuel-oil and fuel-petrochemical. oil and gas.
Refinery profiles
Today, the boundaries between profiles are blurring, enterprises are becoming more universal. For example, the availability of catalytic cracking at refineries makes it possible to establish the production of polypropylene from propylene, which is obtained in significant quantities during cracking as a by-product.
In the Russian oil refining industry, three profiles of oil refineries are distinguished, depending on the oil refining scheme: fuel, fuel-oil, fuel-petrochemical.
Fuel profile refinery
Fuel profile refineries main products are various types of fuel and carbon materials: motor fuel, fuel oil, combustible gases, bitumen, petroleum coke, etc.
The set of installations includes: necessarily - oil distillation, reforming, hydrotreatment; additionally - vacuum distillation, catalytic cracking, isomerization, hydrocracking, coking, etc.
Examples of refineries: Moscow refinery, Achinsk refinery, etc.
The set of installations includes: necessarily - oil distillation, reforming, hydrotreatment; additionally - vacuum distillation, catalytic cracking, isomerization, hydrocracking, coking, etc. At the refinery of the fuel profile, the main products are various types of fuel and carbon materials: motor fuel, fuel oil, combustible gases, bitumen, petroleum coke, etc. Desalted Oil from ELOU is supplied to the Atmospheric Vacuum Distillation Unit, which at Russian refineries is abbreviated AVT - Atmospheric Vacuum Tubular. This name is due to the fact that the heating of raw materials before separating it into fractions is carried out in the coils of tube furnaces due to the heat of fuel combustion and the heat of flue gases.
AVT is divided into two blocks - atmospheric and vacuum distillation.
1. Atmospheric distillation
Atmospheric distillation is intended for the selection of light oil fractions - gasoline, kerosene and diesel, boiling up to 360 ° C, the potential yield of which is 45-60% for oil. The rest of the atmospheric distillation is fuel oil.
The process consists in separating the oil heated in the furnace into separate fractions in a distillation column - a cylindrical vertical apparatus, inside which contact devices (plates) are located, through which the vapor moves up and the liquid moves down. Distillation columns of various sizes and configurations are used in almost all oil refining plants, the number of plates in them varies from 20 to 60. Heat is supplied to the lower part of the column and heat is removed from the upper part of the column, and therefore the temperature in the apparatus gradually decreases from the bottom to the top. As a result, the gasoline fraction is removed from the top of the column in the form of vapors, and the vapors of the kerosene and diesel fractions condense in the corresponding parts of the column and are removed, the fuel oil remains liquid and is pumped out from the bottom of the column.
2. Vacuum distillation
Vacuum distillation is designed to extract oil distillates from fuel oil at fuel-oil profile refineries, or a wide oil fraction (vacuum gas oil) at fuel profile refineries. The remainder of the vacuum distillation is tar.
The need to select oil fractions under vacuum is due to the fact that at temperatures above 380°C, thermal decomposition of hydrocarbons (cracking) begins, and the end of vacuum gasoil boiling is 520°C or more. Therefore, the distillation is carried out at a residual pressure of 40-60 mm Hg. Art., which allows to reduce maximum temperature in the apparatus up to 360-380°C. The vacuum in the column is created using appropriate equipment, the key apparatuses are steam or liquid ejectors.
3. Stabilization and secondary distillation of gasoline
The gasoline fraction obtained at the atmospheric unit contains gases (mainly propane and butane) in a volume that exceeds the quality requirements and cannot be used either as a component of motor gasoline or as commercial straight-run gasoline. In addition, refinery processes aimed at increasing the octane number of gasoline and the production of aromatic hydrocarbons use narrow gasoline fractions as raw materials. This is the reason for the inclusion of this process in the technological scheme of oil refining, in which liquefied gases are distilled off from the gasoline fraction, and it is distilled into 2-5 narrow fractions in the appropriate number of columns. cold raw materials, due to which process fuel is saved, in water and air coolers and are removed from production. A similar heat exchange scheme is used in other refinery units. Modern primary processing units are often combined and may include the above processes in various configurations. The capacity of such installations is from 3 to 6 million tons of crude oil per year. Several primary processing units are being built at the plants in order to avoid a complete shutdown of the plant when one of the units is taken out for repair.
Fuel and oil profile refinery
At the refinery of the fuel and oil profile, in addition to various types of fuels and carbon materials, lubricants are produced: petroleum oils, lubricants, solid paraffins, etc.
The set of installations includes: installations for the production of fuels and installations for the production of oils and lubricants.
Examples: Omsk oil refinery, Yaroslavnefteorgsintez, Lukoil-Nizhegorodnefteorgsintez, etc.
The Volgograd, Ryazan, and Ferghana refineries operate according to the flow scheme (oil version). The difference from the fuel option is that there is no tar thermal cracking process, and fuel oil is sent to the oil block, where it is removed from it in the course of successive processes (in the case of distillates: vacuum distillation, selective purification, dewaxing, hydrotreatment (in the case of the residue, the selective purification process is preceded by deasphalting )) receive distillate and residual base oils, as well as paraffin and ceresin (during their deoiling).
Fuel and petrochemical profile of the refinery
At the fuel and petrochemical refinery, in addition to various types of fuel and carbon materials, petrochemical products are produced: polymers, reagents, etc.
The set of installations includes: installations for the production of fuels and installations for the production of petrochemical products (pyrolysis, production of polyethylene, polypropylene, polystyrene, reforming aimed at the production of individual aromatic hydrocarbons, etc.).
Examples: Salavatnefteorgsintez; Ufaneftekhim.
Petrochemical or complex oil refining provides, along with fuels and oils, the production of raw materials for petrochemistry: aromatic hydrocarbons, paraffins, raw materials for pyrolysis, etc., as well as the production of petrochemical synthesis products. Nizhnekamsknefteorgsintez, Salavatnefteorgsintez, Orsknefteorgsintez, Angarskaya NHC, Yaroslavnefteorgsintez. A feature of this oil refining option is that there is no thermal cracking process (compared to the fuel option), but there is a pyrolysis process. The raw materials for this process are gasoline and diesel fuel. Unsaturated hydrocarbons are obtained: alkenes and alkadienes (ethylene, propylene, isobutylene, butenes, isoamylene, amylene, cyclopentadiene), which are then subjected to extraction and dehydrogenation (target products are divinyl and isoprene), as well as aromatic hydrocarbons (benzene, toluene, ethylbenzene, xylenes ).
Preparation of feedstock for the catalytic cracking process at the refinery
The purpose of preparing feedstock for the catalytic cracking process is to remove heteroatomic compounds, primarily sulfur and nitrogen, and to increase the content of paraffin-naphthenic hydrocarbons. Upgrading of raw materials makes it possible to increase the raw material base of the process and provide an increased yield of gasoline with a low sulfur content with a minimum yield of coke.
The most economical processes are hydrotreatment and hydroconversion of vacuum gas oil. The hydrotreatment of vacuum gas oil makes it possible to reduce only the content of heteroatomic compounds in it. Therefore, this process is used for light gas oils boiling in the range of 360-500°C and containing about 50% paraffin-naphthenic hydrocarbons. In hydroconversion, two types of catalyst are used, which, firstly, make it possible to remove sulfur and nitrogen compounds from raw materials with a boiling point up to 600°C and, secondly, to carry out the hydrogenation of aromatic hydrocarbons. The result is a hydrotreated vacuum gas oil (HVGO) with a sulfur content of not more than 0.2% wt. and a high content of paraffin-naphthenic hydrocarbons (60-70%), the catalytic cracking of which gives a high yield of gasoline and a minimum yield of coke.
At large refineries with an oil capacity of more than 12 million tons / year, the processes of tar deasphalting with propane or light gasoline, thermal adsorption deasphalting of fuel oil and hydroconversion of fuel oil in a three-phase system (catalyst - fuel oil - hydrogen) are also used to prepare catalytic cracking feedstock. For refineries with a capacity of less than 12 million tons/year, these processes are unprofitable.
catalytic cracking products. The following products are formed in the process of catalytic cracking (Table 3.4): dry gas, propane propylene and butane butylene fractions, stable gasoline, light gas oil and bottom product (heavy gas oil).
Light and heavy gas oils are produced in the main fractionator. The remaining products are isolated in the gas fractionation section with subsequent purification from sulfur compounds, for example, in the Merox sections. The outputs and quality indicators of the products obtained are given in the tables.
Hydrocarbon gases of catalytic cracking contain at least 75-80% fatty gases - from propane and propylene to pentane and amylene. In addition, they contain 25-40% isomeric (branched) hydrocarbons. Therefore they are valuable raw material for a number of petrochemical synthesis processes. Dry gas after separation and purification from hydrogen sulfide with monoethanolamine (MEA) at the gas fractionation section is sent to the fuel network of the refinery. 40-50°C. As a result of the reaction: strong corrosive activity, they turn into disulfides - almost neutral compounds. As can be seen from the reaction, the total sulfur content in the products does not change.
The propane-propylene fraction can be used to produce polypropylene and isopropyl alcohol, but the production of diisopropyl ether (DIPE) based on it, a high-octane oxygen-containing component for motor gasolines, is more attractive for the Mozyr Oil Refinery. The butane-butylene fraction will also be used to produce a valuable high-octane component of gasoline - alkylate. It is a product of an isobutane alkylation unit with butylenes. In addition, the butane-butylene fraction can be used for the synthesis of methyl tertiary butyl ether (MTBE), polymeric materials and butyl alcohols. Gasoline is the target product of the MSCC process and is used as a component for the preparation of all brands of commercial gasoline. It has (table 3.6) fairly high density - from 742 to 745 kg / m3 and an octane number - from 92 to 94 points (according to research method). The latter is due to the significant content of alkenes (10-18% wt.) and arenes (20-30% wt.). In addition, the alkanes, alkenes and arenes included in its composition are at least 65% composed of isomeric hydrocarbons with high octane numbers. Thus, catalytic cracking gasoline differs significantly in chemical composition from similar products of other oil refining processes. The characteristic of stable gasoline is given in table 3.6.
Light gas oil and bottoms product, the yields and qualities of which are shown in Table 3.7, are commonly used as components of boiler fuel. They are 50-80% wt. composed of aromatic hydrocarbons.
The low cetane number of light gas oil, as a rule, does not allow its use as a component diesel fuel. However, if necessary, catalytic cracking can be carried out in a mild mode (reduced temperatures and the frequency of catalyst circulation in the reactor). In this case, the cetane number of light gas oil increases, reaching 30-35 points.
The bottom product (heavy gas oil, cracking residue) boils away at temperatures above 350°C. The high content of polycyclic aromatic hydrocarbons in it and in light gas oil can make them a source for obtaining individual solid arenes (naphthalene and phenanthrene), as well as raw materials for the production of carbon black (soot). To do this, the fraction 280-420°C, isolated from catalytic cracking gas oils, is subjected to selective purification, followed by the production of dearomatized raffinate and aromatic concentrate. The latter is the raw material for the production of carbon black.
The hydrogen sulfide produced at the MSCC complex is output to the unit for the production of elemental sulfur in a solution of saturated monoethanolamine (MEA). The output of hydrogen sulfide is 40-50% of the sulfur content in the raw material.
In the process of catalytic cracking of hydrocarbon raw materials, a by-product is formed - coke, which is burned in the regenerator in an air stream, turning into flue gases. The yield of coke depends on the parameters of the technological regime and the quality of raw materials and is 4.1-4.6% wt. on raw materials.
Oil distillation at an oil refinery
After removal of salts and water, oil prepared at ELOU is supplied to primary distillation units for separation into distillate fractions, fuel oil and tar. The obtained fractions and the residue, as a rule, do not meet the requirements of GOST for commercial n / a, therefore, to improve them, as well as to deepen oil refining, the products obtained at AT and AVT units are used as raw materials for secondary (destructive) processes.
The technology of primary distillation of oil has a number of fundamental features due to the nature of the raw materials and the requirements for the resulting products. Oil as a raw material for distillation has the following properties:
Has a continuous flow
The low thermal stability of heavy fractions and residues containing a significant amount of complex low-volatile resinous-asphalten and sulphur-, nitrogen- and organometallic compounds, which sharply worsen the operational properties of n / a and hinder their subsequent processing. Since the temperature of thermal stability of heavy fractions approximately corresponds to the temperature boundary of oil separation between diesel fuel and fuel oil according to the ITC curve, the primary distillation of oil to fuel oil is usually carried out at atmospheric pressure, and the distillation of fuel oil in a vacuum. Also, this choice is due not only to the thermal stability of heavy oil fractions, but also to the technical and economic indicators of the separation process as a whole. In some cases, the temperature limit of oil division is determined by the requirements for the quality of the residue; about half of the diesel fuel fraction is taken with fuel oil to produce boiler fuel.
In recent years, in order to expand the resources of diesel fuel, as well as the feedstock of catalytic cracking - the most important and mastered process that deepens oil refining - at the AT and AVT units, an increasingly deeper selection of the diesel fraction and vacuum gas oil, respectively, is carried out, and to obtain boiler fuel of a given viscosity, visbreaking process of heavy vacuum distillation residue. Thus, the issue of substantiating and choosing the temperature boundary of oil division depends on the options for technological schemes for processing fuel oil and options for oil processing in general. Usually, the distillation of oil and fuel oil is carried out, respectively, at atmospheric pressure and in vacuum at the maximum (without cracking) temperature of heating the raw material with steam stripping of light fractions. The complex composition of distillation residues also requires the organization of a clear separation of distillate fractions from them, including highly efficient phase separation during a single evaporation of raw materials. To do this, baffle elements are installed, which makes it possible to avoid the entrainment of drops by the steam flow.
Rice. Schematic diagrams of an atmospheric column for oil distillation (a) and a vacuum column for fuel oil distillation (b):
1 - power section; 2 - separation section; 3- complex column; 4-side stripping sections; 5-lower stripping section;
The oil heated in the furnace enters the feed section 1 of the complex column 3, where it is evaporated once with separation in the separation section 2 of the distillate fraction vapor from the fuel oil. Vapors, rising from the feed section towards the reflux reflux, are separated by rectification into target fractions, and light-boiling fractions are separated from fuel oil due to steam stripping in the lower stripping section 5. The stripping of low-boiling fractions of the side strips is carried out in the side stripping sections (columns) 4 with water vapor or "deaf" heating. Irrigation in a complex column 3 is created by vapor condensation at the top of the column and in its intermediate sections. The process of separation of fuel oil in a vacuum column is organized in a similar way. Effective phase separation in the feed section of a complex column is achieved by installing special liquid separators and flushing the vapor stream with a flowing liquid. To do this, the operating mode of the column is selected in such a way that phlegm Fn flows from the lower separation section of the complex column into the lower stripping section, the amount of which is due to a certain excess of single evaporation. If we take the flow rate of the excess of single evaporation equal to Fn = (0.05-0.07) F, then the fraction of distillation of raw materials should be by Fn more than the selection of the distillate fraction. the amount of resinous-asphaltenic, sulfurous and organometallic compounds. The distillation columns used in industry make it possible to provide the required degree of separation of distillate fractions with optimal heat consumption required for such energy-intensive processes as primary distillation oil and fuel oil.
Classification of primary oil distillation units at refineries
Technological schemes of primary oil distillation units are usually selected for a specific oil refining option:
fuel,
Fuel and oil.
In the case of shallow oil refining according to the fuel option, its distillation is carried out at AT units (atmospheric tubes); for deep processing - at AVT units (atmospheric-vacuum tubes) of the fuel option and for processing according to the oil option - at AVT units of the oil option. Depending on the variant of oil refining, a different range of fuel and oil fractions is obtained, and at AT units with a shallow fuel variant, components of motor fuels and residual fuel oil (boiler fuel) are obtained. According to the deep fuel option, gasoline, kerosene and diesel fractions are obtained at the atmospheric unit, and fuel oil is subjected to further processing at vacuum distillation units with the release of a wide distillate fraction and tar, followed by their cracking. and AVT of large unit capacity, it is advisable to use a combined technological scheme of the primary distillation unit, which provides simultaneous or separate production of wide and narrow oil fractions from oil along with fuel fractions. Principal technological schemes of such installations are shown in fig. According to this scheme, oil refining is carried out in three stages: atmospheric distillation to obtain fuel fractions and fuel oil, vacuum distillation of fuel oil to obtain narrow oil fractions and tar, and vacuum distillation of a mixture of fuel oil and tar, or to obtain a wide oil fraction and heavy residue used for production tar.
Rice. Fig. 2. Schematic diagrams of primary oil distillation units according to the fuel option for shallow refining AT (a), the fuel option for deep refining ABT (b) and the fuel-oil option (c):
1 - atmospheric column; 2-stripping section; 3- vacuum column;
I-oil; II-light gasoline; III-hydrocarbon gas; IV-heavy
petrol; V-water vapor; VI-kerosene; VII-light diesel fuel; VIII-heavy diesel fuel; IX - fuel oil; X-non-condensable gases and water vapor into the vacuum system; XI - wide oil fraction; XII - tar; XIII - light oil distillate; XIV-medium oil distillate; XV - heavy oil distillate.
The use of two stages of vacuum distillation with simultaneous or separate production of wide and narrow oil fractions gives AVT units significant technological flexibility. 3.
Rice. 3. Combined AVT installation scheme:
1 - electric dehydrator; 2 - stabilization column; 3-atmospheric column;
4 - stripping section; 5-vacuum column of the 1st stage; 6-vacuum column II stage;
1-oil; II - light stable gasoline; III-liquefied gas; IV-hydrocarbon gas; V- heavy gasoline; VI-water vapor; VII-kerosene; VIII - light diesel fuel; IX-heavy diesel fuel; X-light vacuum gas oil; XI - non-condensable gases and water vapor into the vacuum system; XII - light oil distillate; XIII - medium oil distillate; XIV - heavy oil distillate; XV - tar (for deasphalting); XVI - broad oil fraction; XVII-weighted tar (asphalt).
Oil primary distillation products at refineries
Depending on the composition of oil, the variant of its processing and special requirements for fuel and oil fractions, the composition of products of primary oil distillation units may be different. So, during the processing of typical eastern oils, the following fractions are obtained (with conditional boiling limits according to the predominant content of the target components): gasoline n.c. - 140 (180) 0С, kerosene 140 (180)-240 °С, diesel 240-350 0С, vacuum distillate (gas oil) 350-490 °С (500 °С) or narrow vacuum oil strips 350-400, 400-450 and 450-500 0C, heavy residue > 500 °C - tar. The yield of fuel and oil fractions depends primarily on the composition of the oil, i.e., on the potential content of target fractions in oils. As an example, in Table. Table 8.1 shows data on the yield of fuel and oil fractions from Romashkino and Samotlor oils, which differ in the potential content of fuel fractions - the content of fractions up to 350 ° C in these oils is about 46 and 50% (may), respectively (Table 8.1). Let's consider the directions of use products of the primary distillation of oil and fuel oil. Hydrocarbon gas consists mainly of propane and butane. The propane-butane fraction is used as a raw material for a gas fractionation plant to isolate individual hydrocarbons from it and to produce domestic fuel. Depending on the technological regime and instrumentation of the primary distillation of oil, the propane-butane-new fraction can be obtained in a liquefied or gaseous state. -180 °C is used as a raw material for the secondary distillation of gasoline (secondary rectification). Kerosene fraction 120-240 0C after cleaning or upgrading is used as jet fuel; fraction 150-300 0C - as lighting kerosene or diesel fuel component. The fraction of diesel fuel 180-350 °C after cleaning is used as diesel fuel; it is possible to obtain components of light (winter) and heavy (summer) diesel fuel of the appropriate fractional composition, for example, 180-240 and 240-350 °C. The fraction of 200-220 °C paraffinic oils is used as a raw material for the production of liquid paraffins - the basis for the production of synthetic detergents. used in a mixture with vacuum gas oil as a feedstock for a catalytic cracking unit. Fuel oil is the residue of the primary distillation of oil; light fuel oil (> 330 °C) can be used as a boiler fuel, heavy fuel oil (> 360 °C) - as a raw material for subsequent processing into oil fractions to tar. At present, fuel oil can also be used as a feedstock for catalytic cracking or hydrocracking units (previously it was used as a feedstock for thermal cracking units). A wide oil fraction (vacuum gas oil) 350-500 ° C or 350-550 ° C is used as a feedstock for catalytic cracking and hydrocracking units .Narrow oil fractions of 350-400, 400-450 and 450-500 0С, after appropriate purification from sulfur compounds, polycyclic aromatic and normal paraffin hydrocarbons, are used for the production of lubricating oils. Tar - the residue of vacuum distillation of fuel oil - is subjected to further processing in order to obtain residual oils , coke and (or) bitumen, as well as boiler fuel by reducing the viscosity at visbreaking units.
Combined primary oil refining unit at a refinery
In most cases, atmospheric distillation of oil and vacuum distillation of fuel oil are carried out on the same AVT unit, which is often combined with CDU, and sometimes with a gasoline secondary distillation unit. Typical capacities domestic installations primary oil refining 2, 3, 4, 6 million tons / year. Below is a description of the operation of the combined CDU-AVT unit with a section for the secondary distillation of gasoline fractions. k. - 62, 62-140, 140-180, 180-220 (240), 220 (240) -280, 280-350, 350-500 °C (residue is tar). The feedstock entering the plant contains 100–300 mg/l of salts and up to 2% (may.) of water. The content of low-boiling hydrocarbon gases in oil reaches 2.5% (may.) per oil. The plant adopted a two-stage electric desalination scheme, which makes it possible to reduce the salt content to 3-5 mg/l and water content to 0.1% (mae.). The technological scheme of the installation provides for a double evaporation of oil. The head fractions from the first distillation column and the main distillation column, due to the close fractional composition of the products obtained from them, are combined and sent together for stabilization. Petrol fraction n. k. - 180 ° C after stabilization is sent for secondary distillation to isolate fractions n. k. - 62, 62-140 and 140-180 ° С. Alkalinization block is intended for alkaline purification of fractions of n. k. - 62 (component of gasoline) and 140-220 ° С (component of fuel TS-1). The 140-220 °C fraction is washed with water and then dried in electric separators. Crude oil (Fig. 8.17) is pumped by pumps in two streams through heat exchangers, where it is heated to 160 °C due to the heat recovery of hot oil products, and is sent in two parallel streams to electric dehydrators 3 An alkaline solution and a demulsifier are supplied to the intake of the raw pumps. AT electric field high voltage, the emulsion breaks down and the water separates from the oil. Electric dehydrators are designed to operate at 145-160 °C and pressure 1.4-1.6 MPa. Desalted and dehydrated oil is additionally heated in two streams in heat exchangers to 210-250 ° C and sent to the first distillation column 6. From the top of the column, the overhead in the vapor phase is discharged into air-cooled condensers and after cooling in a water cooler to 30-35 ° C enters container 4. The thermal regime in column b is maintained by a “hot” jet coming from furnace 75 with a temperature of 340 0C.
Fig.5 Schematic diagram of the combined CDU-AVT installation
with a capacity of 6 million tons/year of sour oil:
1 - pumps; 2 - heat exchangers; 3-electrodehydrators; 4- containers; 5-condensers-refrigerators; 6 - the first distillation column; 7-main distillation column; 8 - stripping columns; 9 - fractionating absorber; 10- stabilizer; 11, 12 - fractionating columns for the secondary distillation of gasoline; 13 - vacuum column; 14 - vacuum device; 15 furnaces;
I-crude oil; II - desalted oil; III-V-components of light oil products; VI, VII - narrow gasoline fractions (n.c. - 62 ° C and 85-120 ° C, respectively); VIII - decomposition products; IX - vacuum column distillates; X-acute water vapor; XI-tar; XII - benzene fraction (62-85 °С); XIII - heavy fraction of gasoline (above 120 ° C); XIV - dry gas; XV - fatty gas
The rest of the first distillation column 6 - semi-leaned oil - is heated in the furnace of the atmospheric unit of the installation to 360 ° C and enters the main distillation column 7, at the top of which a pressure of 0.15 MPa is maintained. In this column, top acute and two circulation irrigations are used. From the top of the column, vapors of fraction 85-180°C and water vapor exit, which are sent to condensers-refrigerators. Condensate at 30-35 0C is fed into the tank. Fractions 180-220 °C (III), 220-280 °C (IV) and 280-350 0C (V) are removed from the main distillation column 7 in the form of side strips through the corresponding stripping columns 8. Fractions 85-180 °C and 180 -220 ° C alkalized. Fractions 220-280°C and 280-350°C after cooling to 60°C are sent to tanks. Fuel oil (the bottom product of the main distillation column) is fed into the furnace 75 of the vacuum block of the installation, where it is heated to 410 ° C, and with this temperature it passes into the vacuum column 13. The upper side fraction obtained in the vacuum column up to 350 ° C is fed into the main distillation column 7 A fraction of 350-500 0С is removed from the vacuum column in the form of a side stream. This column usually uses one intermediate circulating reflux. The tar from the bottom of the vacuum column is pumped through heat exchangers and coolers and is sent to intermediate tanks at 90 °C. The plant mainly uses air coolers, which helps to reduce water consumption.
The unit provides for the possibility of operation without a vacuum distillation unit. In this case, fuel oil from the bottom of distillation column 7 is pumped through heat exchangers and refrigerators, where it is cooled to 90 °C, and sent to the tank farm. - 180 °C after heating to 170 °C enters the absorber 9. After separation of dry gases in the absorber (XIV), the lower flow is directed to the stabilizer 10. A pressure of 1.2 MPa is maintained in the absorber and stabilizer. In the stabilizer 10, the lower product of the absorber is divided into two streams: upper (up to 85 °C) and lower (above 85 °C). In column 77, the top stream is divided into narrow fractions VI (n.c. - 62 °C) and XII (62-85 °C). The bottom stream from the stabilizer is sent to column 72, where it is separated into fractions VII (85-120°C) and XIII (120-180°C). The thermal regime of the absorber is controlled by the supply of phlegm, which is pumped through the furnace and returns to the bottom of the absorber in the vapor phase. The unit can operate with the secondary distillation unit turned off. In this case, stable gasoline from the bottom of the stabilizer 10 is sent to the heat exchanger, from where the flow through the refrigerator goes to alkalization and then to the tank farm. To remove traces of water, the 140-250 °C fraction is dried in electric separators. 3.5-4m3 of water, 1.1 kg of water vapor, 27-33 kg of fuel are consumed per 1 ton of processed oil. The plant rationally uses the thermal energy of secondary sources. About 35 t/h of steam is produced due to heat recovery from hot streams high pressure. At the beginning, the installation was designed without an ELOU unit; during operation, it was equipped with this unit. At a number of refineries, the productivity of the plant as a result of additional equipment with additional apparatus and facilities exceeded the design one - 6 million tons / year and reached 7-8 million tons / year. The products obtained during the primary distillation of oil are not marketable and are sent for refining (hydrotreatment, dewaxing) or for further processing by destructive secondary processes. These processes provide valuable fuel components and monomers for petrochemical synthesis, deepening oil refining, as well as a wider range of refinery products. Secondary destructive processes include isomerization, reforming, thermal and catalytic cracking, hydrocracking, coking, and oxidation of tar to bitumen. According to the oil version, the corresponding narrow fractions of vacuum gas oil and tar are sent to successive processes of purification and preparation of commercial oils.
Thus, being the main refinery process for both fuel, oil, and petrochemical profiles, primary oil distillation provides all plant units with raw materials. The quality of oil separation - the completeness of the selection of fractions from the potential and clarity of separation - determine the technological parameters and the results of all subsequent processes and, ultimately, the overall material balance of the plant and the quality of commercial oil products.
Oil cracking at refineries
Cracking (English cracking, splitting) - high-temperature processing of oil and its fractions in order to obtain, as a rule, products of a lower molecular weight - motor fuels, lubricating oils, etc., as well as raw materials for the chemical and petrochemical industries. Cracking proceeds with a break C-C connections and the formation of free radicals or carbanions. Simultaneously with the rupture of C-C bonds, dehydrogenation, isomerization, polymerization and condensation of both intermediate and starting substances occur. As a result of the last two processes, so-called. cracked residue (fraction with a boiling point over 350 °C) and petroleum coke.
The world's first industrial installation for continuous thermal oil cracking was created and patented by engineer V. G. Shukhov and his assistant S. P. Gavrilov in 1891 (patent Russian Empire No. 12926 of November 27, 1891). An experimental setup has been made. The scientific and engineering solutions of V. G. Shukhov were repeated by W. Barton during the construction of the first industrial plant in the USA in 1915-1918. The first domestic industrial cracking units were built by V. G. Shukhov in 1934 at the Soviet cracking plant in Baku.
Cracking is carried out by heating the oil feedstock or by simultaneously exposing it to high temperature and catalysts.
In the first case, the process is used to produce gasoline (low-octane components of automotive fuels) and gas oil (components of marine fuel oils, gas turbine and furnace fuels) fractions, highly aromatic petroleum feedstock in the production of carbon black (soot), as well as alpha-olefins (thermal cracking); boilers, as well as automotive and diesel fuels (visbreaking); petroleum coke, as well as hydrocarbon gases, gasolines and kerosene-gas oil fractions; ethylene, propylene, as well as aromatic hydrocarbons (pyrolysis of petroleum feedstock).
In the second case, the process is used to obtain the base components of high-octane gasolines, gas oils, hydrocarbon gases (catalytic cracking); gasoline fractions, jet and diesel fuels, petroleum oils, as well as raw materials for pyrolysis of petroleum fractions and catalytic reforming (hydrocracking).
Other types of pyrolytic splitting of raw materials are also used, for example, the process of obtaining ethylene and acetylene by the action of an electric discharge in methane (electrocracking), carried out at 1000-1300 ° C and 0.14 MPa for 0.01-0.1 s.
Cracking is used to increase the octane number of gasoline (increase the mass fraction of C8H18).
In the course of catalytic cracking, processes of isomerization of alkanes also occur.
Secondary oil refining is carried out by thermal or chemical catalytic splitting of products of primary oil distillation to obtain a larger amount of gasoline fractions, as well as raw materials for the subsequent production of aromatic hydrocarbons - benzene, toluene and others. One of the most common technologies of this cycle is cracking.
In 1891, engineers V. G. Shukhov and S. P. Gavrilov proposed the world's first industrial installation for the continuous implementation of a thermal cracking process: a continuous tubular reactor, where the pipes carry out forced circulation of fuel oil or other heavy oil feedstock, and in the annulus space is supplied with heated flue gases. The yield of light components during the cracking process, from which gasoline, kerosene, diesel fuel can then be prepared, ranges from 40-45 to 55-60%. The cracking process makes it possible to produce components from fuel oil for the production of lubricating oils.
Catalytic cracking was discovered in the 1930s. The catalyst selects from the feedstock and sorbs on itself, first of all, those molecules that are able to dehydrogenate quite easily (give off hydrogen). The resulting unsaturated hydrocarbons, having an increased adsorption capacity, come into contact with the active centers of the catalyst. Polymerization of hydrocarbons occurs, resins and coke appear. The liberated hydrogen takes an active part in the reactions of hydrocracking, isomerization, etc. The cracking product is enriched in light high-quality hydrocarbons and as a result a wide gasoline fraction and diesel fuel fractions are obtained, related to light oil products. As a result, hydrocarbon gases (20%), gasoline fraction (50%), diesel fraction (20%), heavy gas oil and coke are obtained.
Catalytic cracking at refineries
Catalytic cracking is a process of catalytic destructive conversion of heavy distillate petroleum fractions into motor fuels and feedstock for petrochemistry, carbon black and coke production. The process proceeds in the presence of aluminosilicate catalysts at a temperature of 450-530 °C and a pressure of 0.07-0.3 MPa.
The mechanism of most catalytic cracking reactions is satisfactorily explained in terms of the chain carbocation theory. Under the conditions of catalytic cracking, carbocations can exist only in the form of ion pairs carbocation - a negatively charged active center of the surface.
Chemical bases process. The essence of the processes occurring during catalytic cracking is the following reactions:
1) splitting of high-molecular hydrocarbons (actual cracking);
2) isomerization;
3) dehydrogenation of cycloalkanes to arenes.
The destruction of heavy oil feedstock causes the formation of an additional amount of light motor fuels, highest value of which has gasoline. The implementation of all three types of reactions leads to an increase in the octane number of gasoline: with the same structure, the octane numbers of hydrocarbons increase with a decrease in molecular weight; the octane numbers of isoalkanes are higher than those of normal alkanes, and those of arenes are higher than those of cycloalkanes and alkanes.
Alkane transformations. Under the conditions of catalytic cracking, alkanes undergo isomerization and decomposition into alkanes and alkenes of lower molecular weight.
The first stage of the chain process - chain initiation - can occur in two ways.
In the first method, some of the alkane molecules undergo
thermal cracking first. The resulting alkenes detach protons from the catalyst and turn into carbocations.
According to the second method, the formation of a carbocation is possible directly from an alkane by splitting off a hydride ion under the action of a protic center or an aprotic catalyst:
Due to the fact that the detachment of a hydride ion from a tertiary carbon atom requires less energy than from a secondary and primary one, isoalkanes crack much faster than normal alkanes. Chain propagation reactions include all reactions of carbocations that are possible under given conditions. For example, if the primary carbocation С7Н15 was formed at the first stage of the process, then the most probable direction of its transformation would be isomerization into more stable secondary and tertiary structures. The heat released during isomerization can be spent on the splitting of a new ion. Thus, the process of transformation of the C7H15 carbocation consists in a series-parallel alternation of isomerization and p-decay reactions. Since the decomposition of alkyl carbocations with the formation of primary and secondary ions Ci-C3 is much more difficult than with the formation of tertiary ions with a large number carbon atoms, then the rate of catalytic cracking of alkanes increases with chain lengthening. For example, when cracking under the same conditions, the degree of conversion of С5Н12 is 1%; C7H16 -3%; С12Н24 - 18%; C16H34 -42%. The ease (low endothermicity) of the decomposition of ions with the elimination of tertiary carbocations leads to the accumulation of isostructures in the decomposition products of alkanes containing 7 or more carbon atoms. The liberated low molecular weight carbocations after isomerization detach the hydride ion from the molecule of the initial hydrocarbon, and the whole cycle of reactions is repeated. Chain termination occurs when a carbocation meets a catalyst anion.
The rate of catalytic cracking of alkanes is 1-2 orders of magnitude higher than the rate of their thermal cracking.
Transformations of cycloalkanes. The rate of catalytic cracking of cycloalkanes is close to the rate of cracking of alkanes with an equal number of carbon atoms. The main reactions of cycloalkanes are: ring opening with the formation of alkenes and dienes; dehydrogenation leading to the formation of arenes; isomerization of rings and side chains.
The stage of initiation - the emergence of carbocations - for saturated hydrocarbons of cyclic and acyclic structure proceeds in the same way.
The resulting carbocations detach the hydride ion from the molecules of cycloalkanes. The cleavage of the hydride ion from the tertiary carbon atom proceeds more easily than from the secondary one; therefore, the depth of cracking increases with an increase in the number of substituents in the ring.
Neostructures (1,1-dimethylcyclohexane) split off the hydride ion from secondary carbon, so the degree of conversion is close to that of unsubstituted cyclohexane.
The decomposition of the cyclohexyl ion can occur in two ways: with the breaking of C-C bonds and with the splitting of C-H bonds.
As a result of the reaction with the rupture of C-C bonds, alkenes and alkadienes are formed.
The alkenyl ion readily isomerizes to allyl. The most probable reactions of the allyl ion are the abstraction of the hydride ion from the parent molecule or the transfer of a proton to an alkene molecule or a catalyst.
Cycloalkenes undergo catalytic cracking much faster than cycloalkanes.
The decomposition of the cyclohexyl carbocation with the splitting of CH bonds is energetically more favorable, since arenes are formed through intermediate cycloalkene structures.
The yield of arenes reaches 25% or more of the conversion products of cyclohexanes, and the cracking gases of cycloalkanes contain an increased amount of hydrogen compared to the cracking gases of alkane.
The isomerization of cyclohexanes to cyclopentanes and vice versa is also observed. The reaction proceeds through the protonated cyclopropane ring.
Cyclopentanes are more stable under catalytic cracking conditions than cyclohexanes. Therefore, the equilibrium is strongly shifted to the right. However, cyclohexanes undergo dehydrogenation to arenes under these conditions. Removing a product from the reaction sphere shifts the equilibrium to the left. The selectivity of the conversion of cyclohexane to benzene or methylcyclopentane ultimately depends on the catalyst.
In the presence of long side chains in the cycloalkane molecule, side chain isomerization and dealkylation are possible.
Bicyclic cycloalkanes aromatize to a greater extent than monocyclic ones. Thus, during the catalytic cracking of decalin (500°C), the yield of arenes is approximately 33% per converted decalin. Even more aromatic compounds (87.8%) are formed during the cracking of tetralin under the same conditions.
Alkene transformations. The rate of catalytic cracking of alkenes is 2-3 orders of magnitude higher than the rate of cracking of the corresponding alkanes, which is explained by the ease of formation of carbocations from alkenes:
When a proton is attached to an alkene molecule, the same ion is formed as when a hydride ion is split off from an alkane, which determines the generality of their reactions during catalytic cracking - this is isomerization and p-decay. At the same time, alkenes are also characterized by specific reactions of hydrogen redistribution and cyclization.
The essence of the hydrogen redistribution reaction is that in the presence of acid catalysts, some of the alkenes lose hydrogen and turn into polyunsaturated compounds, while another part of the alkenes is hydrogenated by this hydrogen, turning into alkanes.
Alkenes adsorbed on the catalyst gradually lose hydrogen. Highly unsaturated hydrocarbons polymerize, cyclize and, gradually becoming depleted of hydrogen, turn into coke. The cyclization of alkenes can lead to the formation of cyclopentanes, cyclopentenes, and arenes. Five-membered rings isomerize into six-membered rings and also aromatize.
Arena transformations. Unsubstituted arenes are stable under catalytic cracking conditions. Methyl-substituted arenes react at a rate close to that of alkanes. Alkyl derivatives of arenes containing two or more carbon atoms in the chain crack at about the same rate as alkenes. The main reaction of alkyl derivatives of arenes is dealkylation. This is due to the greater affinity of the aromatic ring for the proton than for the alkyl ion.
The reaction rate increases with increasing chain length of the alkyl substituent, as well as in the series: C6H5 - Cnerv< < С6Н5 - Свтор < С6Н5 - Стрет, что обусловлено большой устойчивостью образующихся карбкатионоб.
In the case of methyl-substituted arenes, the elimination of the carbocation is energetically hindered, therefore, the reactions of disproportionation and isomerization at the position of the substituents mainly proceed.
Polycyclic arenes are strongly sorbed on the catalyst and undergo gradual destruction and redistribution of hydrogen with the formation of coke.
Thus, the coke formed on the surface of the catalyst is a mixture of highly unsaturated polymeric resinous alkenes and polycyclic arenes. It blocks the active centers of the catalyst and reduces its activity. To remove coke, the catalyst is periodically subjected to regeneration by oxidation.
Process catalysts and alternative reaction mechanism. Modern cracking catalysts are complex systems consisting of 10-25% zeolite Y in rare earth or decationized form, uniformly distributed in amorphous; aluminosilicate, and molded into microspheres or balls.
The zeolite structure is formed by SiO4 and AlO4 tetrahedra. Aluminum atoms carry a single negative charge, which is compensated by metal cations located in the voids of the crystal lattice. Zeolites with monovalent cations are inactive, since such cations completely compensate for the charge of the AlO4 tetrahedron. Replacing a monovalent cation with a divalent or trivalent cation leads to charge decompensation and creates a high tension electrostatic field, sufficient for the formation of carbocations as a result of the displacement of an electron pair. Amorphous aluminosilicate, in which zeolite is distributed, has its own activity. The catalytically active sites of aluminosilicates are both Bronsted and Lewis acids. The Brønsted acid can be a proton formed from water chemisorbed by a coordinatively unsaturated aluminum atom (a), a proton of a hydroxyl group bonded to an aluminum atom (b) or silicon. Proton-donor centers are of the greatest importance, since completely dehydrated aluminosilicate is practically inactive. In zeolite-containing aluminosilicate catalysts, the role of the metal cation seems to be to increase the proton mobility and stability of Bronsted acid sites, as well as to create an additional number of acid sites by protonation of water molecules. As a result, the rate of reactions on a zeolite-containing catalyst is 2–3 orders of magnitude higher than on amorphous. At the same time, zeolite-containing catalysts have higher thermal and mechanical stability than pure zeolites. The qualitative side of the carbcation theory has received general recognition. However, on its basis, it is not possible to predict the quantitative yield of products even when individual compounds are cracked. It should be noted that the existence of carbocations on the surface of an aluminosilicate catalyst has not been experimentally proven. It is possible that intermediate particles in catalytic cracking are not carbocations (p-complexes), for the formation of which complete heterolytic bond breaking is necessary, but surface complex compounds of hydrocarbons with active sites of the catalyst. Such compounds can be p-complexes, the formation of which requires less energy than for the formation of p-complexes.Macrokinetics of the process.Catalytic cracking, like any heterogeneous catalytic process, proceeds in several stages: the feedstock enters the catalyst surface (external diffusion), penetrates into the catalyst pores (internal diffusion), chemisorbs on the active sites of the catalyst and enters into chemical reactions . Further, the desorption of cracking products and unreacted raw materials from the surface, its diffusion from the catalyst pores and the removal of cracking products from the reaction zone take place. The slowest stage determines the rate of the process. If the process proceeds in the diffusion region, then its rate depends little on temperature. To increase the rate, it is necessary to use a coarse-pored or highly ground, for example, dust-like, catalyst, which will increase the surface of the catalyst. If the slowest stage is a chemical reaction, then the process rate depends mainly on temperature. However, it is possible to increase the rate by increasing the temperature only up to a certain limit, after which the reaction passes into the diffusion region. For the cracking of petroleum fractions, it is practically impossible to describe all chemical reactions. Therefore, they usually confine themselves to consideration of schemes that take into account the main directions and the resulting effect of cracking. In most cases, the kinetics of cracking of petroleum fractions on a zeolite-containing catalyst is represented by a first-order equation. A more accurate description of the kinetics of catalytic cracking of petroleum fractions is achieved by using equations that take into account the deactivation of the catalyst during the reaction. The speed of the process and the yield of cracking products vary significantly depending on the quality of the feedstock, the properties of the catalyst and the completeness of its regeneration, the technological regime and design features of the reaction apparatus. Catalytic cracking in industry. Catalytic cracking on aluminosilicate catalysts is one of the most multi-tonnage processes in the oil refining industry. The purpose of the process is to obtain high-octane gasoline from vacuum distillates of various oils, boiling away in the range of 300-500 ° C. Catalytic cracking on zeolite-containing catalysts is carried out at 450-530 ° C under a pressure close to atmospheric (0.07-0.3 MPa) .In addition to high-octane gasoline, catalytic cracking units also produce hydrocarbon gas, light and heavy gas oils. The quantity and quality of products depend on the characteristics of the feedstock being processed, the catalyst, as well as the process mode. Hydrocarbon gas contains 75-90% of the C3-C4 fraction. It is used after separation in the processes of alkylation, polymerization, for the production of ethylene, propylene, butadiene, isoprene, polyisobutylene, surfactants and other petrochemical products. The gasoline fraction (c. to. 195 ° C) is used as the basic component of motor gasoline. It contains arenes 25-40, alkenes 15-30, cycloalkanes 2-10 and alkanes, mainly isostructure, 35-60% (mass). The octane number of the fraction is 78-85 (according to the motor method). Components boiling above 195°C are separated into fractions. When operating according to the fuel option: 195-350 ° С - light gas oil and >350 ° С - heavy gas oil; when working according to the petrochemical option: 195-270 °C, 270-420 °C and the rest > 420 °C. Light gas oil (195-350 °C) is used as a component of diesel fuel and as a diluent in the production of fuel oils. The cetane number of light catalytic gas oil obtained from paraffinic raw materials is 45-56, from naphtheno-aromatic - 25-35. The 195-270°C fraction is used as a flotation reagent, the 270-420°C fraction is used as a raw material for the production of carbon black. Residual products (>350°C or >420°C) are used as components of boiler fuel or feedstock for thermal cracking and coking processes.
Oil hydrotreating at a refinery
Hydrotreating is carried out on hydrogenating catalysts using aluminum, cobalt and molybdenum compounds. One of the most important processes in oil refining.
The task of the process is the purification of gasoline, kerosene and diesel fractions, as well as vacuum gas oil from sulfur, nitrogen-containing, tar compounds and oxygen. Hydrotreating plants can be fed with recycled distillates from cracking or coking plants, in which case the olefin hydrogenation process also takes place. The capacity of the installations existing in the Russian Federation ranges from 600 to 3000 thousand tons per year. The hydrogen required for hydrotreating reactions comes from catalytic reformers or is produced in special plants.
The raw material is mixed with hydrogen-containing gas with a concentration of 85-95% by volume, coming from circulating compressors that maintain pressure in the system. The resulting mixture is heated in an oven to 280-340 °C, depending on the raw material, then enters the reactor. The reaction takes place on catalysts containing nickel, cobalt or molybdenum under pressure up to 50 atm. Under such conditions, the destruction of sulfur and nitrogen-containing compounds with the formation of hydrogen sulfide and ammonia, as well as the saturation of olefins. In the process, due to thermal decomposition, an insignificant (1.5-2%) amount of low-octane gasoline is formed, and during the hydrotreatment of vacuum gas oil, 6-8% of the diesel fraction is also formed. In the purified diesel fraction, the sulfur content can be reduced from 1.0% to 0.005% and below. Process gases are subjected to purification in order to extract hydrogen sulfide, which is supplied to the production of elemental sulfur or sulfuric acid.
Hydrotreating of petroleum products
Hydrotreating is a process of chemical transformation of substances under the influence of hydrogen at high pressure and temperature.
Hydrotreating of petroleum fractions is aimed at reducing the content of sulfur compounds in commercial petroleum products.
Side effects are saturation of unsaturated hydrocarbons, a decrease in the content of resins, oxygen-containing compounds, as well as hydrocracking of hydrocarbon molecules. The most common oil refining process.
The following oil fractions are subjected to hydrotreatment:
1. Gasoline fractions (straight-run and catalytic cracking);
2. Kerosene fractions;
3. Diesel fuel;
4. Vacuum gas oil;
5. Fractions of oils.
Hydrotreating of gasoline fractions
There are hydrotreating of straight-run gasoline fractions and catalytic cracking gasoline fractions.
1. Hydrotreating of straight-run gasoline fractions.
It is aimed at obtaining hydrotreated gasoline fractions - raw materials for reforming. The process of hydrotreatment of gasoline fractions is based on the reactions of hydrogenolysis and partial destruction of molecules in a hydrogen-containing gas medium, as a result of which organic compounds of sulfur, nitrogen, oxygen, chlorine, metals contained in the feedstock are converted into hydrogen sulfide, ammonia, water, hydrogen chloride and the corresponding hydrocarbons Fuel quality before and after hydrotreatment:
Fuel quality before and after hydrotreatment:
Process parameters: Pressure 1.8-2 MPa; Temperature 350-420°C; Hydrogen content in WSG - 75%; Hydrogen circulation rate 180-300 m³/m³; Catalyst - nickel - molybdenum.
Typical process material balance:
Process parameters: Pressure 1.5-2.2 MPa; Temperature 300-400°C; Hydrogen content in WSG - 75%; Hydrogen circulation rate 180-250 m³/m³; Catalyst - cobalt - molybdenum
Hydrotreatment of diesel fuel. Hydrotreating of diesel fuel is aimed at reducing the content of sulfur and polyaromatic hydrocarbons. Sulfur compounds burn to form sulfur dioxide, which with water forms sulfurous acid, the main source of acid rain. Polyaromatic reduces the cetane number. Vacuum gas oil hydrotreatment is aimed at reducing the content of sulfur and polyaromatic hydrocarbons. Hydrotreated gas oil is a feedstock for catalytic cracking. Sulfur compounds poison the cracking catalyst, and also worsen the quality of the target product of catalytic cracking gasoline (see Hydrotreating of gasoline fractions).
Claus Process (Oxidative Conversion of Hydrogen Sulfide to Elemental Sulfur) in Oil Refining at Refineries
The Claus process is the process of catalytic oxidative conversion of hydrogen sulfide. The source of hydrogen sulfide is natural and industrial. Natural sources are oil and gas fields, volcanic activity, biomass decomposition, etc. Industrial sources - oil and gas processing (hydrotreating and hydrocracking processes), metallurgy, etc.
Hydrogen sulfide, obtained from hydrogenation processes for processing sour and sour oils, gas condensates and amine treatment plants for oil and natural gases, is usually used at refineries for the production of elemental sulfur, sometimes for the production of sulfuric acid.
Methods for the utilization of hydrogen sulfide and the production of sulfur
Due to the tightening of environmental regulations, the following methods can be used to dispose of acid gas obtained as a result of regeneration:
Injection into the reservoir (disposal);
Processing into sulfur according to the Claus method with the production of marketable sulfur in accordance with GOST 127.1 93 ÷ 127.5 93;
Liquid-phase oxidation of H2S with the production of non-commercial or commercial sulfur.
Underground gas injection
Underground storage of acid gas as a method of disposal has found wide application in North America is being implemented in Western Europe and the Middle East. Injection for the purpose of disposal of acid gas as a waste product is carried out in a reservoir that has sufficient absorption capacity - for example, in an unproductive reservoir, in a depleted gas or oil reservoir, and also in some carbonate or salt reservoirs.
Acid gas underground storage processes were actively developed in Canada and the USA in the late 80s, when prices for commercial sulfur were low (respectively, obtaining a small amount of commercial sulfur in the fields was unprofitable), and environmental requirements and control were always more stringent in relation to to the oil and gas producing regions of the world. Geological studies, including modeling, are carried out to select a suitable reservoir for acid gas disposal. As a rule, there is an opportunity to pick up a reservoir for conservation of sour gas, as evidenced by a large number of completed projects in the oil and gas industry in North America - approximately 50 fields in Canada and 40 fields in the USA. In most cases, the injection well is located at a distance of 0.1-4.0 km from the installation (in some cases up to 14-20 km), the absorbing layer is located at a depth of 0.6-2.7 km.
For example, from the Shute Creek gas treatment plant (LaBarge gas field, USA), 1.8 2.5 million m3/day of sour gas (H2S 70%) is injected; the injection unit was commissioned in 2005 as a replacement for the sulfur recovery unit (Claus processes for converting H2S to sulfur and SCOT for tail gases). Thus, acid gas injection can be successfully used both in small-scale and large-scale associated and natural gas treatment plants.
The method of injecting acid gas into the reservoir has many technical features. In the process of developing this method abroad, considerable experience has been accumulated, which can be used in the implementation of similar projects in the Russian Federation and neighboring countries. In Canada, in many fisheries, the process is carried out in climatic conditions corresponding to the conditions of Siberia. operating and environmental organizations abroad, monitoring of possible H2S and CO2 leaks from underground gas storages is carried out. So far, no problematic cases have been observed, and the economic and environmental efficiency of acid gas injection measures is recognized as good.
H2S + 0.5O2 → S + H2O.
The simplified chemistry of the process is as follows:
2H2S + 4Fe3+ → 2S+4H+ + 4Fe2+;
4H+ + О2 + 4Fe2+ → 2Н2О + 4Fe3+ ;
H2S + 0.5O2 → S + H2O.
Iron ions in solution are in the form of a chelate complex.
An example of a successful implementation of the chelate method can be represented by the LO CAT technology from Merichem. According to the company, the product obtained during the regeneration of the absorber is solid sulfur (“sulfur cake”) containing 60% of the main substance (in the USA it can be used as a fertilizer). To obtain a cleaner product - technical sulfur according to GOST 127.1 93 - the technological scheme should be supplemented with washing machines, filters and melters, which reduces the cost of chemicals, but increases capital and operating costs.
Another example of a commercial liquid phase oxidation process is Shell's SulFerox, which is generally schematically similar to the LO CAT process and differs in reactant composition. Figure 2 shows circuit diagram LO CAT process, Figure 3 shows the SulFerox process.
Oil refining in Russia at the refinery
Oil refining in Russia is carried out at 28 large oil refineries (refineries), as well as more than 200 mini-refineries, less than half of which operate legally. The total capacity of refining capacities in Russia is 279 million tons. The largest oil refining capacities are located in the Volga, Siberian and Central federal districts. In 2004, it was noted that these three districts account for more than 70% of the total Russian oil refining capacity. The main production facilities are located mainly near the areas of consumption of petroleum products: in the European part of the country - in the Ryazan, Yaroslavl, Nizhny Novgorod, Leningrad regions, Krasnodar Territory, in the south of Siberia and the Far East - in the cities of Omsk, Angarsk, Achinsk, Khabarovsk, Komsomolsk-on-Amur. In addition, refineries have been built in Bashkiria, the Samara Region and the Perm Territory - regions that were once the largest centers of oil production. Subsequently, when oil production moved to Western Siberia, oil refining capacities in the Urals and the Volga region became redundant. At present, the oil and oil products market in Russia is dominated by several oil companies with a vertically integrated structure that produce and refine oil, as well as the sale of petroleum products, both in bulk and through its own supply and marketing network. The situation on the oil products market depends entirely on the strategy of oil companies, which is formed under the influence of oil prices, commodity structure and geography of demand. Vertically integrated companies own more than 70% of the country's refining capacities. By the beginning of 2010, Rosneft and LUKOIL had the largest installed capacities, they are also leaders in terms of oil refining volumes, 49.6 million tons and 44.3 million tons, respectively. In total, this is almost 40% of raw materials processed in Russia.
History of oil refining in Russia at refineries
Most of the oil refineries in Russia appeared in the two decades after the Great Patriotic War. From 1945 to 1965, 16 refineries were put into operation.
When choosing sites for locating oil refineries, we were guided primarily by the principle of proximity to areas where oil products are consumed. Refineries in the Ryazan, Yaroslavl and Gorky regions were focused on the Central Economic Region; in Leningrad region- to the Leningrad industrial center; in the Krasnodar Territory - to the densely populated North Caucasus region, in the Omsk Region and Angarsk - to the needs of Siberia. However, there was also an increase in the production of petroleum products in the places of oil production. Until the end of the 1960s, the Ural-Volga region was the main oil-producing region of the country, and new refineries were built in Bashkiria, Kuibyshev and Perm regions. These refineries covered the shortage of oil products in Siberia and other regions of Russia, as well as in the union republics of the former USSR.
In 1966-1991, 7 new refineries were built in the USSR, 6 of them outside the RSFSR (in Lisichansk, Mozyr, Mazheikiai, Chardzhou, Chimkent and Pavlodar). The only new oil refinery built after 1966 on the territory of the RSFSR was the Achinsk Oil Refinery, which was put into operation in 1982. In addition, in 1979, oil refining was organized in Nizhnekamsk (Nizhnekamskneftekhim) to meet the demand for raw materials for petrochemical production. In the 1990s, there was a sharp decline in production in oil refining. Due to a sharp reduction in domestic oil consumption, with a total primary processing capacity of 296 million tons per year, in 2000, 168.7 million tons were actually processed, that is, the loading of oil refineries fell to 49.8%. At most refineries, the backward structure of oil refining continued to be maintained with a low share of destructive deepening processes, as well as secondary processes aimed at improving product quality. All this led to the low depth of oil refining and the low quality of the produced oil products. The depth of oil refining in 1999 averaged 67.4% in Russia, and only at the Omsk Refinery did it reach 81.5%, approaching Western European standards.
In subsequent years, an encouraging trend emerged in oil refining. During the period 2002-2007, a steady increase in oil refining volumes was observed with an average annual increase of about 3% in 2002-2004 and 5.5% in 2005-2007. In 2005, the average loading of operating refineries for primary refining was 80%, the refining volume increased from 179 in 2000 to 220 million tons in 2006. Significantly increased investment in oil refining. In 2006 they amounted to 40 billion rubles, which is 12% more than in 2005. The depth of oil refining has also increased.
A number of refineries carried out the construction of complexes for deep oil refining. In 2004, a vacuum gas oil hydrocracking complex was put into operation at the Perm Refinery (LUKOIL); Ryazan Refinery (TNK-BP).
At the end of October 2010, Tatneft Group commissioned a primary oil refining unit with a capacity of 7 million tons per year - part of the complex of oil refineries and petrochemical plants "TANECO" under construction in Nizhnekamsk. The complex is focused on deep processing of heavy sour oil, from which it is planned to produce high-quality petroleum products, including gasoline and diesel fuel of Euro-5 standard. The processing depth will be 97%. At the end of 2010, the Nizhny Novgorod Oil Refinery began producing Euro-4 motor gasoline. In January 2011, the Saratov Refinery began producing Euro-4 diesel fuel.
In total, in 2008-2010, oil companies invested 177 billion rubles in the modernization of refineries. During this period, six new and reconstructed ten operating units for the production of high-quality motor fuels were built at refineries of vertically integrated oil companies.
In the middle of 2011, it was noted that modernization was being carried out at most of the major oil refineries in Russia.
On July 8, 2011, Putin held a meeting on the state of oil refining and the oil products market in the Russian Federation. Putin said that it is necessary to increase the depth of oil refining so that it fully covers the needs of the domestic market for petroleum products. According to Putin, it is necessary to come to grips with increasing the volume of oil refining, and specifically secondary processing, including through such technological processes as isomerization, reforming, and cracking. He suggested starting a gradual convergence of duties on crude oil and dark oil products. Initially, Putin said, it is proposed to reduce the export duty on oil to 60% and set the export duty rate on petroleum products at 66% of the export duty rate on crude oil, and from 2015 to achieve equal rates for fuel oil and crude oil. Putin said that the process of modernizing oil refining should be taken under the most careful control both by the companies themselves and under state control, and all companies should submit specific programs for the reconstruction and development of refineries.
In 2011, tripartite modernization agreements (of oil companies, the government and the Federal Antimonopoly Service) were concluded, which stipulate that by 2015 Russia will produce about 180 million tons of light oil products. The agreements stated that during the modernization of the refinery for the period up to 2020, oil companies will reconstruct and build 124 secondary process units at the refinery. The Ministry of Energy of Russia provides constant control and, within its competence, monitors the implementation of programs to modernize oil refining capacities and commission new refining capacities in order to fulfill Putin's instructions of July 8, 2011 and December 28, 2011.
At the end of August 2011, Putin signed government decree No. 716 establishing new order calculation of export customs duties on petroleum products. The resolution was adopted as part of the introduction of the so-called "60-66" scheme, designed to stimulate the development of the industry and increase the depth of oil refining. According to this scheme, from October 1, 2011, duties on the export of dark oil products (fuel oil, benzene, toluene, xylenes, vaseline, paraffin and lubricating oils), as well as on diesel fuel, were increased from 46.7% of the oil duty to 66%. . At the same time, the export duty on crude oil under the 60-66 scheme was reduced to compensate oil companies for the costs that they would incur in connection with the increase in duties on petroleum products. Previously, the rate was calculated using the formula "oil price based on monitoring for the previous month plus 65% of the difference between this price and $182 per 1 ton ($25 per 1 barrel - the price taken as the main one)", now 60% of the price difference appears in the formula . According to Decree No. 716, from January 1, 2015, the duty on dark oil products will increase to 100% of the duty on crude oil, the duty on light oil will not change.
The refinery modernization program for 2011 was fully implemented by the oil companies. Rosneft has reconstructed five oil refining units: one hydrocracking unit, one diesel fuel hydrotreating unit at the Kuibyshev Refinery and three catalytic reforming units at the Kuibyshev, Syzran and Komsomolsk Refineries. In addition, in 2011, an isomerization unit was commissioned ahead of schedule at the OAO Slavneft-YaNOS refinery with a capacity of 718,000 tons per year. According to the results of 2011, the fuel production plan, which was the basis of the modernization agreements, was even overfulfilled by the companies. Thus, diesel fuel was produced by 1.8 million tons more than it was announced. Deputy head of the FAS Anatoly Golomolzin said: “In fact, for the first time in many years Russian companies began to seriously engage in oil refining. They did not consider it necessary to invest in modernization at all and preferred easier ways. For example, they produced fuel oil and exported it. But after the export customs duties on dark and light oil products were equalized, it became unprofitable to drive fuel oil. Now, from an economic point of view, it is more interesting to produce products with a deeper degree of processing. Moreover, the current system of excises encourages oil companies to produce higher quality light oil products.”
As of the spring of 2012, work was underway to reconstruct and build 40 units, the commissioning of which is planned to be carried out in the period 2013-2015; construction of secondary process units scheduled for commissioning in 2016-2020 was mainly at the planning or basic design stage.
In mid-2012, it was noted that the modernization of the refinery was proceeding within the framework of the established program.
At the end of 2012, the Russian oil refining industry set a record for the volume of oil refining over the past 20 years and for the first time in the past five or six years, avoided the autumn crisis in the gasoline market.
Sources of the article "An oil refinery (Oil Refinery) is"
en.wikipedia.org - the free encyclopedia
ngfr.ru - all about oil and gas
youtube.ru - video hosting
newchemistry.ru - flow diagrams of oil refineries
ecotoc.ru - environmental technologies
atexnik.ru - educational and information portal
newsruss.ru - Russian oil refining industry
Oil is the most important feedstock for Russian industry. Issues related to this resource have always been considered one of the most important for the country's economy. Oil refining in Russia is carried out by specialized enterprises. Next, we will consider the features of this industry in more detail.
General information
Domestic oil refineries began to appear as early as 1745. The first enterprise was founded by the Chumelov brothers on the Ukhta River. It produced kerosene and lubricating oils, which were in high demand at that time. In 1995, primary oil refining amounted to 180 million tons. Among the main factors in the placement of enterprises engaged in this industry are raw materials and consumer.
Industry development
The main oil refineries appeared in Russia in the postwar years. Until 1965, about 16 capacities were created in the country, which is more than half of those currently operating. During the economic transformation of the 1990s, there was a significant decline in production. This was due to a sharp decline in domestic oil consumption. As a result, the quality of the products produced was quite low. The refining depth ratio also fell to 67.4%. Only by 1999 did the Omsk Oil Refinery manage to get closer to European and American standards.
Modern realities
In the past few years, oil refining has begun to reach new level. This is due to investments in this industry. Since 2006, they have amounted to more than 40 billion rubles. In addition, the coefficient of processing depth has also increased significantly. In 2010, by decree of the President of the Russian Federation, it was forbidden to connect to the highways those enterprises in which it did not reach 70%. The head of state explained this by the fact that such plants need serious modernization. In the country as a whole, the number of such mini-enterprises reaches 250. By the end of 2012, it was planned to build a large complex at the end of the pipeline passing to the Pacific Ocean along Eastern Siberia. Its depth of processing was to be about 93%. This indicator will correspond to the level achieved at similar US enterprises. The oil refining industry, which is largely consolidated, is controlled by such companies as Rosneft, Lukoil, Gazprom, Surgutneftegaz, Bashneft, etc.
Industry Significance
Today, oil production and refining are considered one of the most promising industries. The number of large and small enterprises employed in them is constantly increasing. Oil and gas processing brings stable income having a positive impact on the economic condition of the country as a whole. This industry is most developed in the center of the state, Chelyabinsk and Tyumen regions. Oil refinery products are in demand not only within the country, but also abroad. Today, enterprises produce kerosene, gasoline, aviation, rocket, diesel fuel, bitumen, motor oils, fuel oil, and so on. Practically all combines are created near towers. Thanks to this, oil processing and transportation are carried out at minimal cost. The largest enterprises are located in the Volga, Siberian, Central Federal Districts. These refineries account for about 70% of all capacities. Among the constituent entities of the country, Bashkiria occupies a leading position in the industry. Oil and gas processing is carried out in Khanty-Mansiysk, Omsk region. Enterprises also operate in the Krasnodar Territory.
Statistics by region
In the European part of the country, the main production facilities are located in the Leningrad, Nizhny Novgorod, Yaroslavl and Ryazan regions, Krasnodar Territory, in the Far East and southern Siberia, in cities such as Komsomolsk-on-Amur, Khabarovsk, Achinsk, Angarsk, Omsk. Modern oil refineries have been built in the Perm Territory, the Samara Region and Bashkiria. These regions have always been considered the largest centers for oil production. With the relocation of production to Western Siberia, industrial capacities in the Volga region and the Urals became redundant. In 2004, Bashkiria became the leader among the constituent entities of the Russian Federation in primary oil processing. In this region, the figures were at the level of 44 million tons. In 2002, the refineries of Bashkortostan accounted for about 15% of the total volume of oil refining in the Russian Federation. This is about 25.2 million tons. The next place was the Samara region. It gave the country about 17.5 million tons. Next in terms of volume were the Leningrad (14.8 million) and Omsk (13.3 million) regions. The total share of these four entities amounted to 29% of the total Russian oil refining.
Oil refining technology
The production cycle of enterprises includes:
- Preparation of raw materials.
- Primary oil refining.
- Secondary distillation of fractions.
In modern conditions, oil refining is carried out at enterprises equipped with machines and devices that are complex in their design. They operate in conditions of low temperature, high pressure, deep vacuum and often in aggressive environments. The oil refining process includes several stages in combined or separate units. They are designed to produce a wide range of products.
cleaning
During this stage, the processing of raw materials is carried out. The oil coming from the fields is subjected to cleaning. It contains 100-700 mg / l of salts and water (less than 1%). During cleaning, the content of the first component is brought to 3 or less mg/l. The proportion of water in this case is less than 0.1%. Cleaning is carried out on electric desalination plants.
Classification
Any oil refinery uses chemical and physical methods of processing raw materials. By means of the latter, separation into oil and fuel fractions is achieved or the removal of undesirable complex chemical elements. Refining oil by chemical methods makes it possible to obtain new components. These transformations are classified:
Main steps
The main process after purification at CDU is atmospheric distillation. During it, the selection of fuel fractions is carried out: gasoline, diesel and jet fuel, as well as lighting kerosene. Also, during atmospheric distillation, fuel oil is separated. It is used either as a raw material for the next deep processing, or as an element of boiler fuel. The fractions are then refined. They are hydrotreated from heteroatomic compounds. Gasolines undergo catalytic reforming. This process is used to improve the quality of raw materials or to obtain individual aromatic hydrocarbons - a material for petrochemistry. The latter, in particular, include benzene, toluene, xylenes, and so on. Oil is vacuum distilled. This process makes it possible to obtain a broad cut of gas oil. This raw material is further processed in hydro- or catalytic cracking units. As a result, components of motor fuels, oil narrow distillate fractions are obtained. They are then sent to the following stages of purification: selective processing, dewaxing and others. After vacuum distillation remains tar. It can be used as a raw material used in deep processing to obtain additional motor fuels, petroleum coke, construction and road bitumen, or as a component of boiler fuel.
Oil refining methods: hydrotreating
This method is considered the most common. With the help of hydrotreating, sour and sour oil is processed. This method improves the quality of motor fuels. During the process, sulfur, oxygen and nitrogen compounds are removed, olefins of the raw material are hydrogenated in a hydrogen medium on aluminum-cobalt-molybdenum or nickel-molybdenum catalysts at a pressure of 2-4 MPa and a temperature of 300-400 degrees. In other words, during hydrotreatment, organic substances containing nitrogen and sulfur decompose. They react with the hydrogen that circulates in the system. As a result, hydrogen sulfide and ammonia are formed. Received connections are removed from the system. During the entire process, 95-99% of the feedstock is converted into a purified product. Together with this, a small amount of gasoline is formed. The active catalyst undergoes periodic regeneration.
catalytic cracking
It flows without pressure at a temperature of 500-550 degrees on zeolite-containing catalysts. This process is considered the most efficient and deepening oil refining. This is due to the fact that in the course of it, up to 40-60% of a high-octane gasoline component can be obtained from high-boiling fuel oil fractions (vacuum gas oil). In addition, fatty gas is emitted from them (about 10-25%). It, in turn, is used in alkylation plants or ester production to produce high-octane components of auto or aviation gasolines. During cracking, carbon deposits form on the catalyst. They sharply reduce its activity - cracking ability in this case. To restore the component is regenerated. The most common installations in which the circulation of the catalyst is carried out in a fluidized or fluidized bed and in a moving stream.
catalytic reforming
This is a modern and fairly widely used process for producing low- and high-octane gasolines. It is carried out at a temperature of 500 degrees and a pressure of 1-4 MPa in a hydrogen environment on an aluminum-platinum catalyst. With the help of catalytic reforming, mainly chemical transformations of paraffinic and naphthenic hydrocarbons into aromatic hydrocarbons are carried out. As a result, the octane number increases significantly (up to 100 points). The products that are obtained during catalytic reforming include xylenes, toluene, benzene, which are then used in the petrochemical industry. Reformate yields are typically 73-90%. To maintain activity, the catalyst is periodically subjected to regeneration. The lower the pressure in the system, the more often the recovery is performed. The exception to this is the platforming process. During it, the catalyst is not subjected to regeneration. As main feature The whole process is that it takes place in a hydrogen environment, the excess of which is removed from the system. It is much cheaper than specially obtained. Excess hydrogen is then used in hydrogenation processes for oil refining.
Alkylation
This process makes it possible to obtain high-quality components of automotive and aviation gasolines. It is based on the interaction of olefinic and paraffinic hydrocarbons to obtain a higher-boiling paraffinic hydrocarbon. Until recently, industrial variation of this process was limited to the catalytic alkylation of butylene with isobutanes in the presence of hydrofluoric or sulfuric acids. In recent years, in addition to these compounds, propylene, ethylene and even amylenes, and in some cases mixtures of these olefins, have been used.
Isomerization
It is a process during which the conversion of paraffinic low-octane hydrocarbons into the corresponding isoparaffinic fractions having a higher octane number is carried out. The C5 and C6 fractions or their mixtures are predominantly used. In industrial plants, under appropriate conditions, up to 97-99.7% of products can be obtained. Isomerization takes place in a hydrogen environment. The catalyst is periodically regenerated.
Polymerization
This process is the conversion of butylenes and propylene into oligomeric liquid compounds. They are used as components of motor gasolines. These compounds are also feedstock for petrochemical processes. Depending on the starting material, production mode and catalyst, the output volume can vary within fairly wide limits.
Promising directions
Over the past decades, special attention has been paid to combining and strengthening the capacities employed in primary oil refining. Another topical area is the introduction of large-capacity complexes for the planned deepening of the processing of raw materials. Due to this, the production volume of fuel oil will be reduced and the output of light motor fuel, petrochemical products for polymer chemistry and organic synthesis will be increased.
Competitiveness
The oil refining industry today is a very promising industry. It is highly competitive both domestically and internationally. international market. Own production facilities allow you to fully cover the needs within the state. As for imports, they are carried out in relatively small volumes, locally and occasionally. Russia today is considered the largest exporter of petroleum products among other countries. High competitiveness is due to the absolute availability of raw materials and the relatively low level of costs for additional material resources, electricity, and environmental protection. One of the negative factors in this industrial sector is the technological dependence of domestic oil refining on foreign countries. Undoubtedly, this is not the only problem that exists in the industry. At the government level, work is constantly underway to improve the situation in this industrial sector. In particular, programs are being developed to modernize enterprises. Of particular importance in this area is the activity of large oil companies, manufacturers of modern production equipment.
The Gasoil Center company is part of the Votalif group of companies. It is dynamically developing, vertically integrated. It has contractual relations with the largest producers of petroleum products. Constantly expanding the range of customers, partners and the list of products offered. By improving the quality of the services provided, it maximizes the efficiency of doing business to provide its customers with a full range of services. Gasoil Center carries out delivery, quality control, provides timely information about the location of the goods in transit, quickly and correctly draws up documents.
Arsenal has been developing since 2010 production capacity. The strategic goal of the company is to become a leader among traders in the Russian market, as well as the CIS countries. Energy companies, through the diversification of sales markets, one way or another solve their problems through traders who provide an increase in the volume and turnover of capital. Ensuring the reliability of supplies, increasing the efficiency of operations, using the scientific and technical potential - this is all in the development of the company.
Company creation
On November 23, 2009, by the decision of Vadim Valeryevich Akhmedov and Andrey Viktorovich Filatov, the charter of the company was approved. The structure of the company was created, the logo was approved (trademark and name: Gasoil Center Company. The main task of Gasoil Center was set: wholesale trade in petroleum products. The prospect set in 2009: production and processing of oil and gas, has been implemented since 2011. Since From the moment of its foundation, the company's employees strive to achieve three interrelated goals: provide quality customer service, create a stable and strong team, and embrace innovation.
Following these goals, the company operates in Russia, Europe and Asia. Pride in the results of the company's work, supported by feedback on the work of employees. We boldly move into the future. In accordance with the objectives of the activity, the company determines the main thing in them: quality.
We are always responsible to our clients for fulfilling our obligations. The flexibility and initiative of our thinking has a positive effect on cooperation with partners, and the quality of our work puts an end to choosing a reliable partner. The company sells oil products both by Russian railways and by other modes of transport. Delivery of diesel fuel (diesel fuel), gasoline AI-92, AI-95 and others is carried out only under contracts. Our company is part of a group of companies, the sale of petroleum products has been going on since 1995. Main oil products: SPBT, PBA, LPG, NGL, oil, gas, propane, butane, gasoline, DTL, DTZ, heating oil, fuel oil, bitumen.
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