EA002128B1 - Process for oligomerizing of light olefins - Google Patents

Abstract

1. A process for catalytic oligomerizing olefin-containing hydrocarbon fractions C3 and C4 or C4 to gasoline hydrocarbons, wherein contacting feed stream with a oligomerization catalyst, comprising zeolite of a pentacyl group under oligomerization forming a stream enriched with C5+, said produced stream is cooled, passed through a reactor and separating the liquid phase from the reactor to separate a stream, containing C3+ is separated to obtain C5+, C3 and C4 hydrocarbons, characterized in that a stream of light hydrocarbons comprises C1-C4 components and a portion of said stream and a portion of C4 hydrocarbon stream are directed for mixing with an olefin-containing feed material. 2. The process of claim 1, characterized in that a portion of the stream of light hydrocarbons from the separator and a portion of C4 hydrocarbon stream are mixed with the olefin-containing feed material in the hydrocarbon ratio: hydrogen in a recycle from 1: 0.3 to 1:2. 3. The process of claim 1, characterized in that the stream comprising C3+ hydrocarbons is separated so that the stream is directed to a debutanizer to separate C5+ gasoline and the C3-C4 hydrocarbon stream, said C3-C4 hydrocarbon stream is directed to a depropanizator to separate C3 and C4 fractions. 4. The process for catalytic oligomerizing olefin-containing hydrocarbon fractions C3 and C4 of claim 1, characterized in that a stream of products is partially cooled, heat-exchanging therewith self-cooled propylene-containing feed material, which is further mixed a stream of olefin-containing feed material. 5. The process of claim 1, characterized in that the contact of the feed material with the catalyst is interrupted and coke is burnt-off, formed on the catalyst in the process of oligomerization of feed material. 6. The process of claim 5, characterized in that the contact of the feed material with the catalyst is interrupted and the catalyst is contacted with hydrogen-containing gas at a temperature exceeding by 20-50 degree C the temperature of its contact with the feed material until hydrocarbons stop evolving with a stream of hydrogen-containing gas.

Description

In refining processes, a large number of gaseous mixtures of paraffins and olefins are formed under normal conditions, the main sources of which are the processes of catalytic cracking and diesel dewaxing. One of the ways to solve the problem of using olefin-containing gases is the production of components of motor fuels from olefins.

Pentasyl zeolites are effective catalysts for the conversion of lower olefins to C ₅₊ hydrocarbons. At moderate olefin oligomerization temperatures, a mixture of olefin-containing gasoline and diesel fractions is obtained, as well as oil fractions. At elevated temperatures, the dehydrocyclization reaction rate increases, and the content of aromatic and paraffin hydrocarbons in liquid products increases. The properties of the catalyst and technological features allow the oligomerization of olefins with high selectivity for a particular product (1).

Olefin oligomerization reactions are accompanied by heat generation, therefore, the olefin-containing feed is diluted and also the partially converted feed or reaction zone is cooled.

As a diluent for olefins, a gasoline fraction is used (upon receipt of diesel fuel) or gaseous alkanes (upon receipt of gasoline) isolated from the product stream.

A known catalytic method (2) for the conversion of lower olefins to heavier hydrocarbons, comprising mixing a liquid olefin-containing feed with a compressed liquid alkane stream containing mainly C ₃ and C ₄ paraffins, heating the feed and contacting it with an oligomerization catalyst under conditions of conversion of the main part of olefins to hydrocarbons of gasoline and diesel fuel, cooling the stream leaving the reactor in the reboiler section of the debutanizer, debutanizing the cooled stream with the release of a condensed stream of lower alkanes and coal C ₅₊ hydrogens, recycle at least part of the condensed lower alkane hydrocarbon fractionation to give C ₅₊ gasoline and middle distillate. A portion of the lower alkanes can then be fractionated to produce ethane-free liquefied gas.

The known method (3) of oligomerization of lower olefins into liquid hydrocarbons, in which the feed is diluted with a liquid alkac stream, interacts with the oligomerization catalyst, the stream leaving the reactor is cooled and fractionated to produce a condensed recycle stream of lower aliphatic hydrocarbons, a C ₃ - liquid product C _4, liquid product consisting essentially of C ₅₊ hydrocarbons and a gas stream _2, wherein the fractionation is carried out in the following successive stages: debutanizer stream in walking from the reactor to give C ₅₊ hydrocarbons and condensed stream of lower aliphatic hydrocarbon, lower aliphatic deethanizer portion of hydrocarbons to obtain a gas of ethane and C3-C4 product stream and carried recycle at least part of the aliphatic hydrocarbons to dilute olefin feed. The effluent from the reactor can be cooled at least partially during heat exchange with the feed stream and in the deethanizer reboiler.

In the described methods for the oligomerization of olefins, a mixture of C ₁ -C ₄ hydrocarbons enriched in C3 and C4 paraffins obtained by fractionating the stream leaving the reactor with the isolation of a C ₅₊ liquid product is used as a recycle-diluent for raw materials.

The known method (4) of the conversion of light olefins to liquefied gas and aromatic hydrocarbons on a gallium-containing catalyst at a temperature of less than 425 ° C, in which the conversion of the feed to aromatic hydrocarbons is such that the stream leaving the reactor is divided into product streams, one of which is enriched aromatic hydrocarbons C ₆ -C ₈ , and the other with C ₃ and C ₄ paraffins and can be used as recycle for diluting olefin-containing raw materials. With a high olefin content in the C ₃ -C ₄ stream, it can be fractionated to isolate C3 and C4 products and parts of them are used as recycling. The described method for the conversion of olefins is also carried out with the introduction of hydrogen into the reaction zone and the circulation of a hydrogen-containing gas. For fractionation of products, two fractionation columns are used: a debutanizer in which fractions C ₆₊ and C3-C4 are isolated, and a deprotanizer in which fractions C3 and C4 are separated. In the proposed process implementation scheme, light gases are emitted in two separators with intermediate cooling.

As a prototype, a method (5) for converting olefins to C ₅₊ gasoline was isolated. Objects of the invention are techniques for separating liquefied gas components from a product stream leaving the reactor, including reducing losses of C3 components with fuel gas, as well as integrating the process of oligomerization of catalytic cracking gases with a separation unit of a catalytic cracking unit. Method (5) for oligomerization of olefins into C ₅₊ gasoline involves contacting a hydrocarbon stream containing C ₃ and / or C ₄ olefins with a selective mid-pore catalyst in the oligomerization zone under oligomerization conditions to obtain a carbon-rich C ₅₊ stream, separating this stream with the allocation of streams containing C _{3 -} and C ₃₊ hydrocarbons, fractionation of the C ₃₊ stream to produce C ₅₊ gasoline, a C ₄ hydrocarbon rich stream, and a C ₃ hydrocarbon rich stream.

In a preferred embodiment, the separation of the stream leaving the reactor into C _3- and C ₃₊ streams involves passing this stream through a high-temperature and / or low-temperature separator, supplying a gas stream from the separator to the absorber for its deethanization and obtaining off-gas C _2- , feeding liquid phase from the separator to the fractionation column to isolate a C ₃₊ stream. Fractionation of a stream of C ₃₊ in a preferred embodiment includes the supply of this stream to a depropanizer debutanizer and the selection of products: gasoline C ₅₊ , fractions C ₃ and fractions C ₄ .

The alleged invention is a method for the catalytic oligomerization of olefin-containing hydrocarbon fractions C3 and / or C4 into gasoline hydrocarbons, in which the feed is contacted with an oligomerization catalyst containing a zeolite of the pentasil group under oligomerization conditions to form a stream enriched in C ₅₊ hydrocarbons, the resulting product stream is cooled, pass through a separator and fractionate the liquid phase from the separator in order to isolate a stream containing C ₃₊ hydrocarbons and a stream of light hydrocarbons, and a stream, soda containing C ₃₊ hydrocarbons, fractionated to produce C ₅₊ gasoline, C ₃ hydrocarbon fraction and C ₄ hydrocarbon fraction, characterized in that the light hydrocarbon stream contains C ₄ -C ₄ hydrocarbons and part of this stream and part of the C ₄ hydrocarbon fraction are directed to mixing with olefin-containing raw materials.

The proposed method for oligomerization of olefin-containing raw materials allows us to solve the problem of increasing the yield of C ₅₊ hydrocarbons by using a hydrogen-containing recycle enriched in isobutane contained in the C4 fraction.

Mixtures of C ₄ -C ₅ hydrocarbons containing a significant amount of C3 and C4 venison and practically free of dienes, for example, propane-propylene and / or butane-butylene catalytic cracking fractions, can be used as raw materials.

The product stream obtained by contacting the feedstock with an oligomerization catalyst containing a zeolite of the pentasil group under oligomerization conditions includes C ₅₊ gasoline hydrocarbons formed in the oligomerization reactions of olefins and in the reactions of secondary conversions of oligomers and representing C ₅ -Cyu olefins, aromatic hydrocarbons, paraffins and cycloparaffins, as well as unreacted olefins of raw materials, C ₄ -C ₄ paraffins, which are components of the raw materials and are newly formed, as well as hydrogen released during the conversion of cheese s and / or introduced into the composition of the raw material to increase the stability of the catalyst.

The product stream is cooled, partially condensed and C ₃₊ hydrocarbons are separated from the condensate, for which a partially condensed stream is passed through a separator and the liquid phase from the separator is deethanized in a fractionation column to obtain a stream containing C ₃₊ hydrocarbons. Further, the stream containing C ₃₊ hydrocarbons is fractionated with the release of C ₅₊ gasoline, the C3 hydrocarbon fraction and the C4 hydrocarbon fraction, however, the degree of C3 and C4 hydrocarbon recovery as process products is reduced in the adopted simpler scheme for the allocation of a stream containing C ₃ hydrocarbon ₊ , since the non-condensed components C3 and C4 are contained in the vapor-phase stream from the separator, part of which is removed from the process as fuel gas. The use of a part-vapor stream as a recycle of hydrogen-containing gas from a separator containing non-condensed hydrocarbons C3 and C4 allows one to reduce the losses of these hydrocarbons that are inevitable in the accepted method of hydrocarbon recovery

3+.

In the proposed method for the oligomerization of olefin-containing fractions C3 and / or C4, a recycle stream is formed from a hydrogen-containing stream of light hydrocarbons C ₄ -C ₄ isolated in a separator from a partially condensed product stream, and from a C4 hydrocarbon fraction containing isobutane and separated from the liquid phase of the separator by fractionation . Thus, it is possible to control the composition of the recycle. So, in order to increase the yield of gasoline, it is possible to form a recycle enriched in comparison with the known methods (with an equal volume of recycle) with isobutane, which allows to increase the contribution of the alkylation reactions of olefins of raw materials with isobutane competing with their oligomerization.

With an increase in dilution of the olefin-containing feedstock with isobutane, there is also an increase in the conversion of propylene in the feedstock and in the composition of the resulting gasoline, an increase in the proportion of isoolefins, including C ₅ and C ₆ isoolefins, active in the esterification reaction, which allows to increase the octane number of the obtained gasoline during esterification olefins with methanol.

Thus, the proposed method for oligomerization of olefin containing fractions C3 and / or C4 simplifies the scheme for the recovery of C ₃₊ hydrocarbons without significant losses of C3 and C4 hydrocarbons and allows you to adjust the composition of the recycle in accordance with the properties of the catalyst and the composition of the feed in order to increase the yield of gasoline.

The catalyst used in the proposed method should be active in the oligomerization of lower olefins, in particular propylene and butylenes, into gasoline hydrocarbons and have stability acceptable for industrial use. Effective catalysts are catalysts based on zeolites of the pentasil group and metallosilicates with a similar structure. The synthesis and structure of these materials are described in the technical literature and are widely known.

The forms of zeolites that are active in oligomerization have acidic properties; these are hydrogen and mixed cation-substituted forms of zeolites activated during high-temperature processing. The catalysts may also contain metals or their oxides, as well as phosphorus or boron oxides introduced by various known methods and affecting their catalytic properties and stability.

The zeolites are molded with a binder component, for example, aluminum hydroxide or aluminosilicate, in the form of spheres or extrudates, subjected to heat treatment to give them strength and activation of catalytic properties. The microspherical catalyst contains, as a rule, 25-35 wt.% Zeolite, extrudates - 50-70 wt.%. The contact of the feedstock with the catalyst is carried out in a fluidized bed of a microspherical catalyst or in a stationary layer of a granular catalyst. The conditions for the oligomerization of olefins into gasoline hydrocarbons depend on the properties of the catalyst and are usually in the following ranges: temperature 280-420 ° C, pressure 1-3 MPa, volumetric feed rate of olefins 0.5-6.0 h ^-1 . Oligomerization conditions must be stringent enough to limit the composition of the products to gasoline hydrocarbons.

The value of the recycle is determined from the condition of an admissible adiabatic temperature increase in the catalyst bed and depends on the thermal effect of the catalytic process of the conversion of olefin-containing raw materials under the selected conditions and on the design features of the reactor, which determine the possibility of heat removal from the reaction zone.

The recycle stream consists of C ₃ -C ₄ hydrocarbons and hydrogen. The preferred recycle composition is formed when the volume ratio of hydrocarbons and hydrogen is from 1: 0.3 to 1: 2. The method is carried out according to the technological scheme shown in FIG. 1 where

- raw material capacity,

- heat exchange unit for heating raw materials,

- raw material heating furnace,

- reactor block,

5, 6, 7 - air cooler,

8, 9, 10, 11 - water refrigerator,

- separator

13, 14, 15, 16 - heaters,

17, 18, 19 - irrigation capacity,

- heat exchanger

- capacity fraction C4,

- a circulation compressor for hydrogen-containing gas,

- column deethanizer,

- debutanizer column,

- column depropanizer,

- throttle

I - olefin-containing raw materials,

II - stream entering the reactor,

III - stream leaving the reactor,

IV - chilled product stream,

V - recycle hydrogen-containing gas,

VI - gas from the separator to the fuel network,

VII - liquid-phase flow from the separator,

VIII - nutrition deethanizer,

IX - pairs from the top of the deethanizer,

X - deethanizer reflux,

XI is the main product of the deethanizer,

XII - cubic product deethanizer,

XIII - pairs from the top of the debutanizer,

XIV - debutanizer reflux,

XV - the main product of the debutanizer,

XVI - stable gasoline,

XVII - nutrition depropanizer,

XVIII - couples from the top of the depropanizer,

XIX - fraction C ₃ -product,

XX - reflux depropanizer,

XXI - cubic product of depropanizer,

XXII - recycling fraction C ₄ ,

XXIII - fraction C ₄ -product,

XXIV - power debutanizer,

XXV - hydrogen-containing gas.

Olefin-containing feedstock I from feed tank 1 is mixed with hydrogen-containing gas CFC, recycle of hydrogen-containing gas V and recycle of fraction C ₄ XXII, heated in heat exchange unit 2 and in furnace 3 and feed stream II are fed into reactor unit 4, where, under oligomerization conditions, contact of the feedstock with a zeolite oligomerization catalyst. The product stream III leaving the reactor block is cooled in a heat exchange unit 2, in an air cooler 5, and in a water cooler 8. The cooled and partially condensed product stream is fed to a separator 12. A portion of the vapor-phase stream from the separator is circulated by a circulation compressor to be mixed with the olefin-containing raw material as a recycle hydrogen-containing gas, part is removed from the installation as fuel gas VI. The liquid phase VII from the separator is heated in a heat exchanger 13 and stream VIII is fed to a deethanizer column 23. The column is equipped with a condenser refrigerator 9, reflux tank 17, heater 14, as well as raw, reflux and food pumps. In the column, fuel gas XI and bottoms product XII, consisting of C ₃₊ hydrocarbons, are isolated. The bottoms product XII is passed through a choke 26 and the cooled stream XXX is fed to a debutanizer 24. Vapors from the top of debutanized 002128 RA XIII, consisting mainly of C ₃ and C ₄ hydrocarbons, are cooled in air 6 and water 10 refrigerators and cold reflux is removed from reflux tank 18 X1U debutanizer and liquefied hydrocarbon fraction C ₃ C ₄ . The head product of the debutanizer is heated in a heat exchanger 20 and fed to a depropanizer 25 to isolate fractions C ₃ and C ₄ . The cubic product of the debutanizer - stable gasoline ХУ1 - is cooled with a C ₃ -C ₄ fraction and removed from the installation as a commercial product. The depropanizer is equipped with an air cooler 7, a reflux tank 19 and a heater 16. A part of the bottoms product XXI — fraction C ₄ containing n-butane and isobutane — is cooled in a water cooler 11 and sent to the reservoir of fraction C ₄ 21 and from there stream XXI is a recycling of fraction C4 - for mixing with olefin-containing raw materials. The HUSH vapors from the top of the depropanizer are cooled in an air cooler 7 and the cold irrigation of the XX depropanizer and the head product of the depropanizer fraction C ₃ are removed from the reflux tank 19. The C ₄ fraction (stream XXIII) is also removed from the installation as a product.

In the case of processing olefin-containing fractions C ₃ and C ₄ , i.e. propane-propylene and butane-butylene fractions, a throttled feed propane-propylene fraction can be used to cool the stream of products leaving the reactor: at least part of the propane-propylene fraction is cooled during throttling, then heated by heat exchange with the stream of products leaving the reactor reactor, and mixed in an ejector with a stream of olefin-containing raw materials. The use of propane cold instead of water cooling makes it possible to reduce the temperature in the separator, where the primary separation of the product flow takes place, and to reduce the content of C ₃₊ components in the gas phase of the separator.

In FIG. Figure 2 shows the flow chart according to which the method of catalytic oligomerization of propane-propylene and butane-butylene fractions is carried out using heat exchange products with self-cooled (during throttling) propylene-containing raw materials for partial cooling of the flow of products.

Marked on the diagram

- raw material capacity,

- heat exchange unit for heating raw materials,

- raw material heating furnace,

- reactor block,

5, 6, 7 - air cooler,

8, 8A, 8B, 8B - heat exchanger,

9, 10, 11 - water refrigerator,

- separator

13, 14, 15, 16 - heater,

17, 18, 19 - irrigation capacity,

- heat exchanger

- capacity fraction C4,

- a circulation compressor for hydrogen-containing gas,

- column deethanizer,

- debutanizer column,

- column-depropanizer, 26, 27 - throttle,

- ejector

- olefin-containing raw materials,

GB - propane-propylene fraction per throttle,

ΣΒ - propane-propylene fraction after the throttle,

Ш - propane-propylene fraction for ejection,

Щ - working flow of the ejector,

Ш - flow from the ejector,

II - stream entering the reactor,

III - stream leaving the reactor,

IV - chilled product stream,

V - recycle hydrogen-containing gas,

VI - gas from the separator to the fuel network,

VII - liquid-phase flow from the separator,

VIII - nutrition deethanizer,

IX - pairs from the top of the deethanizer,

X - deethanizer reflux,

XI is the main product of the deethanizer,

XII - cubic product deethanizer,

XIII - pairs from the top of the debutanizer,

XIV - debutanizer reflux,

XV - the main product of the debutanizer,

XVI - stable gasoline,

XVII - nutrition depropanizer,

XVIII - couples from the top of the depropanizer,

XIX - fraction C ₃ -product,

XX - reflux depropanizer,

XXI - cubic product of depropanizer,

XXII - recycling fraction C ₄ ,

XXIII - fraction C ₄ -product,

XXIV - nutrition debutanizer.

From the raw material tank 1, the mixture of raw fractions - olefin-containing raw materials - is mixed with the recycle of the C ₄ fraction (stream XXII) and into the heat exchange unit for heating the raw material 2. Next, a propane-propylene fraction used as a refrigerant is ejected with a part of the stream.

Part of the propane-propylene feed fraction (stream 1B) is sent to the inductor 27 and a cooled stream ΣΒ is obtained, which is heated during heat exchange with the product stream in the heat exchanger 8A and sent to the ejector 28. Stream 1G is ejected with a part of the mixture of olefin-containing raw materials and recycling fraction C ₄ (stream 1E), and the resulting stream 1E, together with a hydrogen-containing gas recycle V, is sent to be mixed with the remainder of the mixture of olefin-containing feed and recycle of the C ₄ fraction. The resulting stream is heated in the heat exchanger 8 of the furnace willow 3. In the reactor block 4 serves the feed stream II, heated to the temperature of the beginning of the reaction, the raw material is contacted with the oligomerization catalyst and a product stream III is enriched in C ₅₊ hydrocarbons. The product stream is cooled in a heat exchanger 8B, in an air cooler 5 and heat exchangers 8B and 8A. The partially condensed product stream IV is sent to the separator 12. A part of the gas phase from the separator (stream V) is circulated by a compressor 22 for mixing with the olefin-containing raw material, and a part (stream VI) is sent to the fuel network. The liquid phase VII from the separator is heated in heat exchangers 8B, 8B and 13 and separated according to the scheme also shown in FIG. 1 and described above to obtain stable gasoline, fuel gas, C ₃ fraction and C ₄ fraction.

It is known that hydrocarbon conversion catalysts accumulate coke - polynuclear spatial structures depleted in hydrogen, filling the inner and outer surfaces of the catalyst and causing a decrease in its activity. Coke is periodically burned in an oxygen-containing gas to form carbon oxides and water. A mixture of nitrogen and air is often used as a regenerating gas, dosing the oxygen content to regulate the burning rate of coke, which is accompanied by significant heat generation, in order to prevent structural changes in the catalyst and its irreversible deactivation. The amount of coke that accumulates on the catalyst until its activity decreases below an acceptable level depends on the properties of the catalyst, and the rate of coke formation also depends on the composition of the feed and the process conditions.

The procedure for burning coke formed on the catalyst in an oxygen-containing medium (oxidative regeneration of the catalyst) is well known, but may have some features related to the composition of the catalyst and its properties and is not the subject of the invention. Typically, oxidative regeneration is carried out at 350-600 ° C, with a stepwise increase in temperature, with an increase in the oxygen concentration in the regenerating gas from 0.5% to 21 vol.%. Burning coke leads to an almost complete restoration of the activity of the catalyst and can be carried out periodically, for which the contact of the feed with the catalyst is interrupted.

It is known that a decrease in catalyst activity also occurs as a result of the formation of unsaturated polymer hydrocarbon molecules, which are not coke proper, but are adsorbed in the pores of the catalyst and block its active surface. Favorable conditions for the formation of such polymers are realized under the conditions of oligomerization of olefin-containing raw materials. It is known that treatment of a coked catalyst with an inert or hydrogen-containing gas stream at elevated temperature leads to cracking of such compounds and to an increase in catalyst activity. Periodic reactivation of the zeolite-containing catalyst for the oligomerization of olefins when it is in contact with a hydrogen-containing gas at a temperature 20-50 ° C higher than the contact temperature of the feedstock with the catalyst allows to increase the duration of the catalyst between oxidative regenerations. The duration of contact of the catalyst with a hydrogen-containing gas is determined by the properties of the catalyst and the contact conditions and can be from 2 to 10 hours

The following are examples of the implementation of the proposed method of oligomerization of olefin-containing raw materials.

Example 1

The oligomerization of the butane-butylene fraction is carried out according to the scheme shown in FIG. 1. The zeolite-containing oligomerization catalyst is prepared as follows: the catalyst mass obtained by mixing the ammonium form (sodium oxide content less than 0.1 wt.%) Of the zeolite of the CVM pentasil group (TU 38.401528-85), aluminum hydroxide and zinc nitrate is extruded, the catalyst granules are dried , dried at 120 ° C for 5 hours, calcined in a muffle furnace at 520-550 ° C for 5 hours. A catalyst of the following composition was obtained (wt.%): zeolite - 69, alumina - 29, zinc oxide - 2.

The contact of the feedstock with the catalyst is carried out at a temperature at the inlet of the reactor 420 ° C, a pressure of 1.6 MPa, a volumetric feed rate of 3.4 h ^-1 . The hydrogen concentration in the recycle 66.6 vol.%, Which corresponds to the volume ratio of hydrocarbons and hydrogen in the recycle 1: 2.

The physical characteristics of the main flows are given in table. 1, the composition of the main flows is in table. 2.

Example 2

The mixture of propane-propylene fraction (PPF) and butane-butylene fraction is oligomerized according to the scheme shown in FIG. 2. Use the catalyst according to example 1. The contact of the feedstock with the catalyst is carried out at a temperature at the inlet of the reactor 420 ° C, a pressure of 1.6 MPa, a volumetric feed rate of 3.9 h ^-1 . The hydrogen concentration in the recycle is 23.1 vol.%, Which corresponds to the volume ratio of hydrocarbons: hydrogen 1: 0.3. The physical characteristics of the main flows are given in table. 3, the composition of the main flows is in table. 4.

Example 3

The mixture of propane-propylene and butane-butylene fraction is oligomerized according to the scheme shown in FIG. 2. Use the catalyst according to example 1. Oligomerization conditions: temperature at the inlet of the reactor 420 ° C, pressure 1.6 MPa, the volumetric feed rate of 3.0 h ^-1 . The hydrogen concentration in the recycle is 30.4 vol.%, Which corresponds to the volumetric ratio of hydrocarbons to hydrogen in the recycle 1: 0.44. The physical characteristics of the main flows are given in table. 5, their composition is in table. 6.

Example 4

The butane-butylene fraction is contacted with the catalyst according to example 1 and under the same conditions, diluting the feedstock with propane to the olefin content in the stream entering the reactor is 13.21%. The composition of the butane butylene fraction is as in Example 1. The composition of the stream leaving the reactor is analyzed.

Example 5

A mixture of the propane-propylene fraction and the butane-butylene fraction (the initial olefin-containing feedstock of Example 2) is contacted with the catalyst of Example 1 under the oligomerization conditions of Example 2, diluting the feedstock with propylene to the olefin content in the stream entering the reactor, 16.50 wt.%. . The composition of the stream leaving the reactor is analyzed.

Example 6

A mixture of the propane-propylene and butane-butylene fractions (initial olefin-containing feedstock of Example 3) is contacted with the catalyst of example 1 under the oligomerization conditions of Example 3, diluting the initial olefin-containing feedstock with propane to an olefin content in the stream entering the reactor of 39.99 wt.% . The composition of the products leaving the reactor is analyzed.

In the table. 7 shows the results of experiments confirming the effect of isobutane on the oligomerization of C ₃ and C ₄ olefins. When oligomerization of the feedstock according to examples 1, 2 and 3 in accordance with the claimed method, with recycle of the stream of light hydrocarbons from the separator and fraction C4 containing isobutane, the feed stream entering the reactor, compared to the feedstock, is enriched with isobutane. During oligomerization of the olefin-containing feedstock according to Examples 4, 5 and 6 — examples for comparison — the isobutane / olefin ratio inherent in the feedstock is retained in the stream entering the reactor.

The data obtained indicate that with an increase in the content of isobutane oligomerization in the feed, the yield of C ₅₊ hydrocarbons and the content of isoolefins in them, including C5 and C6 isoolefins, are formed during esterification with methanol to produce high octane ethers that increase the detonation resistance of gasoline.

Example 7

The mixture of the butane-butylene and propane-propylene fractions is converted from the catalytic cracking unit of Example 2 until 1 wt.% Olefins appear in the stream leaving the reactor. The duration of the catalyst with the conversion of raw olefins is not less than 94% - 280 hours, the yield of stable gasoline for raw materials - 61.90 wt.%.

Stop the feed to the reactor and burn out the coke formed on the catalyst with a mixture of air and nitrogen. The temperature in the reactor is increased from 420 to 520 ° C at the inlet stepwise, every 2 hours at 20 ° C for 1 hour of heating. The feed rate of regeneration gas is 3 h ^-1 , the oxygen concentration is increased from 1 to 21 vol.% At least every 2 hours of the isothermal mode and set sequentially at 3, 6, 10, 15 and 21 vol.% During heating of the catalyst. Analysis of the stream leaving the reactor for the content of carbon oxides and water indicates the completion of coke combustion at 520 ° C. After regeneration of the catalyst, the temperature in the nitrogen stream is reduced to 420 ° C and the contact of the feed with the catalyst is continued under the same conditions until 1 wt.% Olefins appear in the stream exiting the reactor. The duration of the catalyst with a conversion of at least 94% is 296 hours, the yield of stable gasoline for raw materials is 63.12 wt.%. The contact of the feed with the catalyst is interrupted and its regeneration is carried out as described above.

After repeated regeneration of the catalyst, the temperature in the reactor was reduced to 420 ° C and the feed was contacted with the catalyst under the same conditions for 286 hours, while the conversion of the olefins of the feed was not less than 94%, the yield of stable gasoline was 61.20 wt.%. The contact of the feedstock with the catalyst is interrupted, nitrogen is passed through the catalyst bed at 420-440 ° С for 4 hours at a volumetric feed rate of 5 h ^-1 , then the catalyst is contacted with gas containing 94-98 vol.% Hydrogen (the rest is nitrogen mixture , argon, methane and carbon dioxide of variable composition) at a flow rate of 140 m ³ per 1 m ^{3 of} catalyst, increasing the temperature at the inlet of the reactor from 440 to 470 ° C evenly for 20 hours until the evolution of hydrocarbons heavier than methane with a stream of hydrogen ceases. The contact of the catalyst with the hydrogen-containing gas is terminated, the temperature in the reactor is reduced to 420 ° C., and the olefin-containing feed is oligomerized in Example 2 until 1 wt.% Olefins appear in the stream leaving the reactor. The duration of the catalyst with the conversion of olefins is not less than 94% 190 h, the yield of stable gasoline for raw materials is 61.54 wt.%.

Table 1

Stream / No. Consumption kg / h Temperature ° C Pressure, MPa Olefin-containing raw materials / 1 10,000 35 1.00 Recycle fraction C ₄ / XX11 1000 40 1.80

Hydrogen gas recycle / ν 19000 35 1.25 Hydrogen-containing gas / ΧΧν 300 40 1.80 Reactor feed / 11 30300 420 1,60 Reactor flow / ΙΙΙ 30300 450 1.40 Separation flow / ΐν 30300 35 1.25 Gas from the separator to the fuel network / νΐ 3450 35 1.25 Liquid-phase flow from the separator / νΐΐ 7850 35 1.25 Deethanizer Power / νΐΙΙ 7850 90 2,51 Pairs from the top of the deethanizer / ΙΧ 5834 59 2,50 Reflux deethanizer / X 5673 35 2,50 Fuel gas / ΧΙ 161 35 2,50 VAT product deethanizer / ΧΙΙ 7689 157 2,52 Power debutanizer / XX ^ 7689 133 1.27 Pairs from the top of the debutanizer / ΧΙΙΙ 54891 72 1.23 Debutanizer Reflux / X ^ 52513 45 1.23 Stable Gasoline / ΧνΙ 5311 177 1.25 Depropanizer nutrition / ΧνΙΙ 2378 128 2.15 Pairs from the top of the Depropanizer / HUSH 42583 61 2.13 Depropanizer reflux / ΧΧ 42191 45 2.13 Propane fraction-product / ΧΙΧ 392 45 2.13 Cubic product depropanizer / ΧΧΙ 1986 107 2.15 Butane fraction-product / ΧΧΙΙΙ 986 107 2.15

table 2

Stream number The composition of the stream, wt.% CH4 C2H4 ^C 3 ^H 8 C3H6 ^ns 4 ⁿ 10 ^IS 4 ^N 10 C4H8 C5 + H2 N2 CO2 one 2 3 4 5 6 7 8 nine 10 eleven 12 Ι 0.60 0.40 8.40 51.00 39.60 ΧΧΙΙ 0.01 27.60 72.93 ν 1.87 9.97 24.85 14.18 33.55 5.93 7.23 1.20 1.18 ΙΙ 1.25 6.27 15,80 0.13 12.55 40.28 13.08 3.70 5.17 0.89 0.88 ΙΙΙ 1.40 7.57 19.94 13.40 29.80 20.76 5.36 0.89 0.88 νΙΙ 0,03 0.72 5.92 11.17 19.05 63.04 0.02 0.01 0.04 ΙΧ 0.22 17.92 71.65 1.78 7.76 0,07 0.05 0.02 0.53 Χ 0.19 17.43 72.06 1.82 7.88 0.09 0,03 0.02 0.48 ΧΙ 1.30 34.90 56.97 0.58 3.20 0.73 0.08 0.27 1.97 ΧΙΙ 4.85 11.39 19.38 64.38 ΧΙΙΙ 15.68 22.63 61.69 ΧνΙ 6.36 0.43 93.21 ΧΙΧ 0,03 94.97 0.05 4.95 ΧΧν 7.93 63.74 13.84 14.49

Table 3

Flow Consumption kg / h Temperature ° C Pressure, MPa one 2 3 4 Butane-butylene fraction / ΙΑ 6350 35 1.00 PPF per choke / 1B 3650 35 1,50 PPF after throttle / ΙΒ 3650 4 0.60 PPF for ejection / 1G 3650 eleven 0.60 Цикл / ΧΧΙΙ fraction recycling 16900 40 1.80 Hydrogen gas recycle / ν 3100 twenty 1.16 Ejector Workflow / 1D 19500 338 4.30 Ejector flow / ΙΕ 23150 292 1.80 Reactor feed / ΙΙ 30000 420 1,60 Reactor flow / ΙΙΙ 30000 450 1.40 Separation flow / ΐν 30000 twenty 1.16 Gas from the separator to the fuel network / νΙ 851 twenty 1.16 Liquid-phase flow from the separator / νΐΐ 26049 twenty 1.16 Deethanizer Power / νΙΙΙ 26049 90 2,51

002 128 16

Pairs from the top of the deethanizer / IX 30630 60 2,50 Fuel gas / X1 848 35 2,50 Reflux deethanizer / X 29782 35 2,50 VAT product deethanizer / X11 25200 125 2,52 Power debutanizer / XX1U 25200 92 1.27 Pairs from the top of the debutanizer / XIII 60248 79 1.23 Debutanizer / KSU Reflux 41226 46 1.23 Stable gasoline / HCG 6178 176 1.25 Depropanizer / HUGG Nutrition 19022 70 2.15 Pairs from the top of the depropanizer / HUGGG 33400 61 2.13 Reflux Depropanizer / XX 31558 45 2.13 Propane fraction product / XH 1841 45 2.13 Cubic Product Depropanizer / XXI 17181 111 2.15 Butane fraction-product / ХХШ 281 111 2.15

Table 4

Stream number The composition of the stream, wt.% CH4 C2H4 ^C 3 ^H 8 C3H6 ^ns 4 ⁿ 10 ^IS 4 ^N 10 C4H8 C5 + H2 one 2 3 4 5 6 7 8 nine 10 8.50 51.50 40.00 IN 26,20 7380 Hhp 0.13 60.14 39.70 0,03 V 3.53 11.77 21.19 28,99 26.44 1.15 6.93 DG 0.10 46.04 42.92 10.94 W 4.21 11.64 38.78 36.15 9.22 II 0.36 1.22 5.46 8.97 38.68 35,99 8.53 0,07 0.72 III 0.53 2.69 10.15 39.64 26.64 19.42 0.93 VII 0,07 1.32 8.49 41.26 26.65 22.19 0.02 GC 0.37 20.85 65.26 5.19 8.29 0.04 HT 2.16 40.28 51.81 1,69 3.44 0.62 X 0.32 20.29 65.65 5.29 8.43 0.02 Hi 7.03 42.59 27.44 22.94 XH 0.01 9.32 54.40 36.27 Hbh 0.05 94.95 0.51 4.49 XM 6.22 0.26 93.52

Table 5

Stream / No. Consumption kg / h Temperature ° C Pressure, MPa one 2 3 4 Olefin-containing raw materials 8500 35 1,50 PPF per throttle / GB 1500 35 1,50 PPF after throttle 1500 4 0.65 PPF for ejection / GG 1500 nineteen 0.65 Recycle fraction C ₄ / HHI 2120 40 1.80 Hydrogen gas recycle / ν 955 51 1.80 Ejector / DG Workflow 8500 336 4.32 Ejector flow 10,000 291 1.80 Rector's raw materials / I 13075 420 1,60 The stream leaving the reactor / III Щ075 450 1.40 Separation flow / W 13075 twenty 1.16 Gas from the separator to the fuel network / UG 958 twenty 1.16 Liquid-phase flow from the separator / UI 11162 twenty 1.16 Deethanizer / MI Power 11162 90 2,51 Pairs from the top of the deethanizer 16602 54 2,50 Fuel Gas / XI 489 35 2,50 Reflux deethanizer / X 16113 35 2,50 VAT product deethanizer / CI 10673 125 2,52 Power debutanizer / KHGU 10673 97 1.27 Pairs from the top of the debutanizer / XH 56804 67 1.23

Reflux debutanizer / X1U 51171 45 1.23 Stable gasoline / HU! 5041 176 1.25 Food depropanizer / XU11 5632 90 2.15 Pairs from the top of the Depropanizer / HUSH 41190 61 2.13 Reflux Depropanizer / XX 39623 45 2.13 Propane fraction product / X1X 1567 45 2.13 VAT product depropanizer / XX1 4065 106 2.15 Butane fraction-product / ХХШ 1945 106 2.15

Table 6

Stream number The composition of the stream, wt.%. CH4 C2H6 ^C 3 ^H 8 C ₃ H6 ^ns 4 ⁿ 10 ^IS 4 ^N 10 C4H8 C5 + H2 one 2 3 4 5 6 7 8 nine 10 ΙΑ 6.67 13.62 6.35 38.47 29.89 1B 26,20 73.80 Xx11 0.02 21.51 78.47 V 3.32 16.06 37.73 7.09 28.41 2.06 5.33 1D 5.34 14.91 9.38 46.46 23.91 ΙΕ 8.47 0.64 7.97 39.49 43,43 II 0.24 1.17 10.16 20.57 8.14 39.81 19.42 0.10 0.39 III 0.54 3.94 18.91 9.95 29.46 36.41 0.79 VII 0,07 1.86 15.69 10.44 29.64 42.28 0.02 gh 0.29 23.59 70.74 0.67 4.67 0.01 0,03 Xi 1,56 42,42 53.57 0.21 1.88 0.36 X 0.26 23.02 71.26 0.67 4.76 0.01 0.02 Hi 13.95 10.91 30.91 44,23 XH 0.01 26.43 15,54 58.03 XM 5.74 0.62 93.64 XH 0,03 94.97 0.05 4.95

Table 7

Data on the composition of raw materials and products Example one 4 2 5 3 6 Characteristics of raw materials - n-butane / olefins 3.05 1.29 2.18 0, 63 1.00 0, 63 - olefin content, wt.% 13.21 13.21 16.50 16.50 39,99 39,99 Product Feature: the yield of C ₅₊ * hydrocarbons to olefins of the feed, wt.% 129.14 96.14 117.27 83.70 90.80 83.70 the composition of hydrocarbons With ₅₊ , wt.%: n-olefins 12.91 22.54 13.12 22.93 16.00 19.40 iso-olefins 53.62 43.50 50.30 40.11 43.14 38.50 including 2me butene-1 4.32 2,50 4.10 2.63 2.42 2,33 2 me butene-2 12,20 7, 90 12.04 8.20 9.51 7.80 2Me Penten-2 1.72 1,63 1,60 1,54 1,58 1.20 3Me Penten-2 4.45 4.00 4.10 4.00 3.90 3.62 2,3 dIme butene-1 0.30 0.18 0.27 0.18 0.18 0.10 2,3 dIme butene-2 0.57 0.37 0.56 0.38 0.47 0.30 total C ₅ and C ₆ iso-olefins active in esterification 23.56 16.58 22.67 16.93 18.06 15.35

* in the product stream leaving the reactor

Claims (6)

1. The method of catalytic oligomerization of olefin-containing hydrocarbon fractions C ₃ and C ₄ or C ₄ into gasoline hydrocarbons in which the feed is contacted with an oligomerization catalyst containing a zeolite of the pentasil group under oligomerization conditions to form a stream enriched in C ₅₊ hydrocarbons of ₁₉₊ , the resulting product stream is cooled, passed through a separator and fractionated the liquid phase from the separator in order to separate a stream containing C ₃₊ hydrocarbons and a stream of light hydrocarbons and a stream containing C ₃₊ hydrocarbons is fractionated to produce C ₅₊ gasoline, a C ₃ hydrocarbon fraction and a carbon fraction levodorodov C _4, characterized in that the light hydrocarbon stream comprising components of C _r C ₄ and part of this stream and a portion of the C ₄ hydrocarbon fraction is sent to mixing with the olefin-containing feedstock. 2. The method according to claim 1, characterized in that part of the C4 hydrocarbon fraction and part of the light hydrocarbon stream from the separator are sent for mixing with the olefin-containing raw material at a volume ratio of hydrocarbons: hydrogen in recycle from 1: 0.3 to 1: 2. 3. The method of claim 1, wherein the stream containing C ₃₊ hydrocarbons is fractionated as follows: debutanizer stream is directed into and recovered C ₅₊ gasoline hydrocarbons stream and a C ₃ -C ₄ and C ₃ hydrocarbon stream C4 is sent to a depropanizer and fractions C3 and C4 are isolated. 4. The method for the catalytic oligomerization of hydrocarbon olefin fractions C ₃ and C ₄ according to claim 1, characterized in that the product stream is partially cooled by heat exchange with a self-cooled propylene-containing feed, which is then mixed in an ejector with a stream of olefin-containing feed. 5. The method according to claim 1, characterized in that the contact of the feedstock with the catalyst is interrupted and coke burned out formed on the catalyst under conditions of oligomerization of the feedstock. 6. The method according to claim 5, characterized in that the contact of the feedstock with the catalyst is interrupted and the contact of the catalyst with the hydrogen-containing gas is carried out at a temperature 20-50 ° C higher than the temperature of its contact with the feed until the hydrocarbon evolution stops with the flow of the hydrogen-containing gas.