SU1754763A1 - Method for processing of gasoline fractions - Google Patents

Abstract

Using the increase in the octane number of gasoline fractions, oil refining The essence of the invention: the separation of the original gasoline by distillation into an unstable head gas fraction nc - 62 ° C and a vat residue directed to zeoforming at 300-480 ° C and a pressure of 1-4 MPa Catalysate is sent to a stabilization column, from the top of which a fraction of liquefied gases is taken as a side stream — high-octane stable gasoline, and from the bottom a kerosene fraction is taken out as a distillation residue. An obvious fraction is fed to the cross section of the stabilization column above the output level of the side stream, but below the level of the supply of acute irrigation. As a result, a reduction in energy costs is achieved.

Description

The invention relates to methods for processing gasoline fractions separated from petroleum and gas condensates in order to obtain high octane gasolines, and can be used in refineries and petrochemical plants, as well as refineries of oil and gas fields.

There is a method of processing gasoline fractions, according to which gasoline fractions n. Are obtained from gas condensate along with the main product, diesel fuel. to. -100 ° C and above, used as fuel for carburetor engines

The disadvantage of this method is the low octane number of the gasoline fractions obtained, the low content of light (start-up fractions), and their significant difference from commercial gasoline in chemical composition.

A method of processing gasoline fractions is also known, according to which gasoline by distillation is divided into fractions nk-85 and 85-100 ° C. The second fraction is subjected to deep hydrotreating and catalytic reforming in an environment of hydrogen-containing gas in order to increase its octane number. mix with the first fraction and receive commodity high-octane gasoline.

The disadvantage of this method is that the increase in the octane number of the 85-180 ° C fraction is carried out in the presence of a circulating hydrogen-containing gas under a pressure of 1.5-4.0 MPa, which significantly increases the operating costs of the process.

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In addition, mixing a stable, reformed fraction of 85-180 ° C with an unstable fraction of NK-85 ° C leads to a decrease in the pressure of saturated vapors of commercial gasoline and to large losses during storage and consumption.

The closest to the proposed technical solution adopted for the prototype is a method of processing gasoline fractions, according to which the gasoline fraction separated from gas condensate nk-140 ° C or nk-170 ° C is separated in a distillation column on unstable head fraction NK-58 ° C (NK, - 62 ° C) and the residual fraction 58-140 ° C (62-170 ° C). After heating and evaporation, the latter is subjected to zeoforming in a cyclic reactor. Zeoforming catalyst is stabilized and rectified to produce hydrocarbon gas, a target gasoline fraction, and a kerosene component.

The disadvantage of this method is that the unstable head fraction, n.k., is 58 ° C (n, k.- 62 ° C), having a relatively high octane number, or is not mixed with the target gasoline fraction, or mixed with it. without prior stabilization, which leads to loss during storage and use. In addition, this method is characterized by low efficiency, expressed in increased costs of condensation and cooling of the acute irrigation of the stabilization column.

The purpose of the invention is to develop such a method that would reduce the loss of the final gasoline fraction, as well as increase the efficiency of the process by reducing the energy costs of condensation and cooling of the reflux of the stabilization column.

This goal is achieved by the fact that the condensed unstable head strand fraction of NK-62 ° C obtained during the rectification of the starting gasoline with a boiling end of 140 ° C (170 ° C), without preheating, is sent to the stabilization column of catalytic converting the reflux into the space between the output of a stable gasoline fraction and the introduction of acute irrigation,

The essence of the proposed method is illustrated in the drawing, where 1 is the gasoline fraction of the raw material; 2 - heat exchanger; Rectification column; 4 - pairs of unstable head thrust fraction; 5.17 - condensers-refrigerators; 6.18 - gas separators; 7.19 hydrocarbon gas; 8.20 - acute irrigation; 9 - unstable

headspin fraction; 10 - stabilization column; 11 - target gasoline fraction; 12 - raw materials of the process of zeoforming; 13 - tube furnace; 14 - zeoforming reactor; 15 - catalyzed; 16 - head of liquefied gases; 21-residue (kerosene component).

The method is carried out as follows.

Raw gasoline fraction 1 is heated in heat exchanger 2 and fed to the distillation column 3, From the top of the distillation column 3, a pair of unstable head fraction 4 is withdrawn, which is condensed in the condenser-cooler 5 and fed to the gas separator 6. From the gas separator 6, the hydrocarbon gas 7 and an unstable headstream fraction 9, sent without heating to the stabilization column 10, into the space between the output of the target gasoline fraction 11 and the introduction of acute irrigation 20.

Part of fraction 9 in the form of acute reflux 8 is returned to distillation column 3. From the lower distillation column 3, the feedstock of the process of zeoforming 12 is removed, which is heated and evaporated in a tube furnace 13 and fed to one of the reactors the zeoforming operating in the catalyst regeneration cycle .

From the zeoforming reactor 14, catalyzate is sent to stabilization column 10. From the top of stabilization column 10, the head of liquefied gases 16 is vaporized, which is condensed in the condenser-cooler 17 and fed to the gas separator 18. From the gas separator 18, hydrocarbon gas 19 containing impurities of hydrogen obtained in the zeoforming reactor 14, and the head of liquefied gases 16, part of which in the form of acute irrigation 20 are fed to the stabilization column 10. From the bottom of the stabilization column 10, the remainder 21, which may be Components kerosene fractions.

Thus, according to the proposed method, the unstable head dragon fraction is fed without heating to the stabilization column in the space between the output of the target gasoline fraction and the introduction of acute irrigation.

PRI me R. At the gasoline fraction processing unit with a capacity of 19.6 thousand tonnes / year, the raw gasoline fraction is separated in the distillation column into an unstable head distillation fraction n.k.-62 ° C in the amount of 0.74 ton / h and the residual fraction 62-170 ° C-raw materials of the process of zeoforming in the amount of 1.98 t / h

Fraction 62-170 ° С contains, wt.%: N-alloys 22, iso-alloys 19, cycloalkenes 51 and arenes 8. The octane number of the motor and research methods fraction is 56 and 61.2 points, respectively.

The raw materials of the zeoforming process are heated in a tube furnace and fed to the reactor. In the zeoforming reactor, in the presence of an incorporated VK zeolite catalyst at a pressure of 2.0 MPa, a bulk flow rate of feed 2, and a temperature at the reactor inlet of 420 ° C, the catalytic conversion of hydrocarbons occurs. Due to the endothermic effect at the outlet of the reactor, the temperature is reduced to 350 ° C. The reaction products contain, wt%: n-alkanes C2-C4 35, iso-alkanes Cs + 13, cyclans 27 and arenes 25. Next, the reaction products are cooled in a heat exchanger to 212 ° C and sent to a stabilization column, the condensed unstable head portion fraction n, k.-62 ° C at a temperature of 35 ° C, where it stabilizes and simultaneously plays the role of irrigation, enters the space between the output of the target gasoline fraction and the injection of acute irrigation. From the top of the stabilization column a hydrocarbon gas (0.78 t / h) and a liquefied gas head (0.06 t / h), from the middle part — the target gasoline fraction (high-octane gasoline component with an octane rating by engine and research methods — 85.1 and 94 paragraph, respectively) in the amount of 1.77 t / h, and from the bottom take the residue in an amount of 0.1 t / h.

The main indicators of the installation of processing gasoline fractions on the proposed and known (prototype) methods are given in the table.

From the data of the table it follows that the described method makes it possible to reduce losses from gasoline evaporation while storing it by 468 tons / year by stabilizing the unstable head gas fraction, - 62 ° C, together with stabilization and rectification of zeoforming catalysate;

POOCHT1 process efficiency by reducing the multiplicity of acute irrigation in the stabilization column and, as a result, reduce the cost of condensation and

cooling this irrigation.

Estimated economic effect from the introduction of the inventive method at the installation of processing gasoline fractions with a capacity of 19.6 thousand tons / year in comparison

with the prototype, where there is no provision for the joint stabilization of the unstable head fever of the faction nk-62 ° C with zeoforming catalysing, it will cost 33 thousand rubles a year. At the same time, at the expense of reducing the loss of gasoline A-76 from its evaporation, the savings amount to 15 thousand rubles, 18 thousand rubles. - by reducing the cost of condensation and cooling of the sharp oro-pig stabilization column.

Claims (1)

Invention Formula The method of processing gasoline fractions by dividing the source gasoline in a distillation column into an unstable head fraction n.k.-62 ° C, part of which is fed to the top of the column as an acute irrigation, and the vat residue, directed after heating and evaporating to zeoforming at a temperature of 300 480 ° C and a pressure of 1-4 MPa, followed by stabilization of the stabilization gas obtained for the ata 7 shzat in the stabilization column by taking stabilization gas from the top of the column and a fraction of liquefied gases partially used as sharp irrigation on the top of the stake nna, as well as to obtain a side stream of high-octane gasoline fraction and stable output from the column bottom residue Distillation of kerosene as comgo nets, which is due to the fact that, in order to reduce gasoline losses and reduce energy costs during gas condensation and cooling of the condensation, the Tah7GbLav yugo fraction n, k.-b2 ° C is fed into the intermediate section of the stabilization column between the introduction of acute irrigation and the output of a stable gasoline fraction. Main indicators of the operation of the gasoline fraction processing unit Indicators Plant capacity by raw gasoline fraction: thous.t / year t / h Obtained (taking into account losses), t / h: Headache unstable fraction n.k. - 62 ° C Raw Tse & Forming Process Zeoforming Catalyst Hydrocarbon gas Head of liquefied gases Target gasoline fraction (high-octane component of gasoline) Residue (component of kerosene) Commodity gasoline A-76 Commodity gasoline A-76 taking into account evaporation losses Gasoline loss from evaporating storage, t / year Pressure, MPa: top of the distillation column in the zeoforming reactor of the top of the stabilization column Temperature, ° С: in the rectification column: top of the entrance of raw materials bottom in the zeoforming reactor in the stabilization column: top the entrance of unstable headplate fractions catalysis inlet output target gasoline fraction bottom Short acute irrigation, kg / kg: in a distillation column in a stabilization column Diameter, mm: rectification column stabilization column Heat load condenser-cooler of stabilization column, MJ / h Heat transfer surface of condenser-cooler of stabilization column, m 19.6 2.72 0.74 1.98 1.97 0.80 1.07 0.1 1.81 1.74 504 0.49 2.0 1.0 80 150 180 420 60 195 132 207 2.5 5.2 600 450 2162 270 19.6 2.72 0.74 1.98 1.97 0.78 0.06 1.77 0.1 1.77 1,765 36 0.49 2.0 1.2 80 150 180 420 70 35,212,146,220 2.5 3.3 600 400 1646 150  Taking into account the stabilized golovyuyu progonnoy fraction. The decrease compared with the prototype was due to a reduction in the amount of acute irrigation. Prototype According to the invention 19.6 2.72 19.6 2.72 0.74 1.98 1.97 0.78 0.06 1.77 0.1 1.77 1,765 36 0.49 2.0 1.2 80 150 180 420 70 35,212,146,220 2.5 3.3 600 400 2162 270 1646 150 13 l W i rizhl G vA / T 2 / r / // v hl; 4/4 /four / 15 H //