RU2598074C1 - Method for catalytic conversion of hydrocarbon raw material - Google Patents

Abstract

FIELD: oil refining industry.

SUBSTANCE: invention relates to oil refining, petrochemical and chemical industries, in particular, to methods of processing heavy oils and bitumens. Method for catalytic conversion of hydrocarbon raw material involves contacting in a converter of the hydrocarbon material in a fluidized bed with a regenerated catalyst to obtain products of cracking and a coked catalyst, coke burning out of the coked catalyst to produce the regenerated catalyst and exhaust gases, steam overheating due to the steam heat exchange with the exhaust gases to produce superheated steam, where obtaining the products of cracking is carried out in presence of a hydrogen-containing gas, obtaining the hydrogen-containing gas is performed by steam catalytic reforming, which is carried out at feed of the said superheated steam and methane-containing gases, the obtained hydrogen-containing gas is additionally heated with the exhaust gases and fed into the converter.

EFFECT: technical result is reduced consumption of energy resources, expanded capabilities of processing heavy oil, increased efficiency of obtaining light products, reduced catalyst consumption, improved efficiency of processing heavy oil, higher output of end products.

8 cl, 1 dwg, 5 tbl

Description

Technical field

The invention relates to the refining, petrochemical and chemical industries, in particular to methods for processing heavy oils and bitumen.

State of the art

Current trends in the development of the catalytic cracking process are associated with the processing of heavier petroleum feedstocks and residues, combining fuel and petrochemical options (production of gasoline, diesel fuel, propylene) and reducing the contact of feedstock and catalyst. Promising are the development of Russian scientists to develop the hydrocracking process, including increasing the yield of liquid products, which implies the implementation of the process in a three-phase and moving catalyst bed. However, the hydroprocessing processes currently offered on the market on traditional heterogeneous catalysts, due to the high content of metals, high molecular weight resinous substances and asphaltenes in the feed, are characterized by a number of significant disadvantages, namely, the low conversion of the feed, the high hydrogen pressure used, the rapid deactivation of the catalyst and its blocking surface due to rapidly proceeding reactions of coking and accumulation of metals on its surface / Khadzhiev S.N., Gerzeliev I.M., Kapustin V.M. et al. Catalytic cracking as a part of modern deep oil refining complexes // Petrochemistry. - 2011. - T. 51, No. 1 /.

The prior art method for the preparation and deep processing of hydrocarbon raw materials, including heating the raw materials and hydrogen, obtaining final products, characterized in that the liquid (oil, fuel oil, residues of oil refining and petrochemicals), the feedstock is heated to a temperature above 20-50 ° C and subjected thermal and / or thermomechanical (non-catalytic) cracking, molecular hydrogen and / or light hydrogen-containing media enriched with hydrogen (natural or associated gas, gas and light fractions of oil refining and petrochemicals), if not the necessities are heated separately from the feedstock, sent at a higher pressure than the pressure in the heating and cracking stages, to the stage for producing active atomic hydrogen and / or light radicals into a reactor or reactor pack with a catalyst heated to the required temperature, after which the obtained active hydrogen and / or light radicals are sent to the heating and cracking zone of the raw material for the reaction, the reaction products are sent to the separation stage, part of the gas and light fractions, as well as unreacted hydrogen and / or light to prenatal-containing starting media after the separation stage are sent to the beginning of the process and introduced into the feedstock, light target reaction fractions after the separation stage, mainly with a boiling point up to 350-360 ° C, are partially or completely sent to the stage of obtaining light target commercial products (liquefied gas , gasoline, kerosene, diesel fuel) and / or partially returned and introduced into the feedstock, the heavy residue after the separation stage, mainly with a boiling point of 360 ° C and above, partially or completely on They are used to produce heavy commercial products (bitumen, coke) and, possibly, partially or completely sent for reprocessing by this method at the beginning of the process together with the feedstock, while the stages of heating and cracking of the feedstock and / or the residue of separation, heating of hydrogen and / or hydrogen-containing media and catalyst, the production of active atomic hydrogen and / or light radicals and separation into the light part and heavy residue are combined in one apparatus, and the ratio of the surface of the reactor or reactors with the catalyst to the volume of the zone agreva and / or cracking the raw material must be increased so as to maximize the area of interaction (reaction) of hydrogen atoms and / or light and heated radicals or the cracked hydrocarbon feedstock to effective use of reactive products (see. RF patent No. 2387697 for the invention, publ. 04/27/2010).

The disadvantage of this method is the lack of efficiency of oil refining, since both fast and slow processes occur in the reactor at the same time, and an unproductive energy consumption occurs to produce active atomic hydrogen, i.e. high energy consumption.

The prior art method of catalytic conversion in a catalytic conversion reactor, comprising one or more reaction zones for carrying out the reaction, where the feedstock in the form of a hydrocarbon oil is subjected to a catalytic conversion reaction in the presence of an inhibitor, and the vapor of the reagent optionally containing the inhibitor is separated from coke, deposited on the catalyst, and the target product containing ethylene and propylene is obtained by separating the reagent vapor, the catalyst is separated from coke and reduced for re use in the reactor, and the ratio of the inhibitor to the feedstock is 0.001-15% by weight, the inhibitor is selected from a substance having the ability to produce hydrogen or having a reducing ability, or having adsorption ability on the active center of acid catalysts and mixtures thereof, and the substance having the ability to produce hydrogen or containing hydrogen, selected from hydrogen, tetrahydronaphthalene, decalin, catalytic dry cracked gas, coke oven dry gas and mixtures thereof, substances m having reducing ability is carbon monoxide, and a substance having an adsorptivity to the active site of acidic catalysts selected from methanol, ethanol, ammonia, pyridine, and mixtures thereof (see. RF patent No. 2417976 for the invention, publ. 05/10/2011).

The technical solution is limited to the production of olefins. In addition, the energy costs for producing hydrogen and the decomposition of inhibitors are too high, which reduces the efficiency of the process.

The prior art method for the processing of hydrocarbon raw materials, which consists in the fact that the processed raw materials are heated to a temperature in the range from 30 ° C to 15 ° C higher than the temperature at which thermal decomposition of the hydrocarbon feed begins, and superheated water vapor is prepared at a temperature of 500 ° C or more. From up to 800 ° C, heated processed raw materials and superheated water vapor are fed into a hollow reactor having two reaction chambers in series and interconnected, the volume of the first reaction chamber less than the volume of the second reaction chamber in which the reaction of thermal cracking of the feed occurs, while providing an average residence time of the reaction mixture in the first reaction chamber of less than 0.1 seconds and an average residence time of the reaction mixture in the second reaction chamber of at least 10 seconds, the reaction products are removed from the reactor. Heavy hydrocarbons, such as heavy and superheavy oils, ultra-viscous oils, natural bitumen, and oil residues, such as atmospheric distillation residues and products based on them, are processed (see RF patent No. 2518080 for an invention, published June 10, 2014).

The disadvantage of this method is the need for the consumption of liquid fuel for the preparation of superheated water vapor with a temperature from 500 ° C to 800 ° C and the limited ability to obtain valuable light fractions due to the absence of catalytic effects on the process, which increases the cost of implementing the method and reduces its effectiveness.

Partially, these disadvantages are solved in the method of converting hydrocarbon fractions of petroleum origin into high-quality mixture of hydrocarbons as fuel, which includes the following stages:

- catalytic cracking of a hydrocarbon fraction in a fluidized bed of catalyst (CCF) at a temperature of from 400 to 650 ° C and at a pressure of from 100 to 500 kPa (from 1 to 5 bar) in the presence of a catalyst containing EK8-10 zeolite, wherein said catalyst contains at least at least two components, where these components are catalytic cracking catalysts (a) a component containing one or more catalytic cracking catalysts in a fluidized bed, and (b) a component containing EC8-10 zeolite to produce a light recycle gas la (LRH),

- hydrotreatment of light recycle gas oil,

- the interaction of hydrotreated light recycle gas oil obtained in the previous stage of hydrotreating, with hydrogen in the presence of a catalytic system (see RF patent No. 2518119 for the invention, publ. 06/10/2014).

The technical solution is limited by the effect of hydrogen on only one of the products of the catalytic cracking of the hydrocarbon fraction in the fluidized bed of the catalyst, which limits the use of heavy oil, leads to increased consumption of catalytic cracking catalysts, reduces the possibility of preparing raw materials with a heated coolant, which impairs the applicability of the method.

A more effective method for the catalytic conversion of hydrocarbon feedstock, comprising contacting the hydrocarbon feedstock with a regenerated catalyst to produce cracking products and a coked catalyst; burning coke from a coked catalyst to produce a regenerated catalyst and off-gas; and heat exchanging said hydrocarbon feed and said off-gas to heat said hydrocarbon feed before contacting said hydrocarbon feed with a regenerated catalyst. In addition, the method further includes the implementation of overheating of water vapor through heat transfer of the specified water vapor with the specified exhaust gases (see RF patent No. 2491321 for the invention, publ. 08/27/2013 - prototype).

The disadvantage of the prototype method is the limitation of the hydrogenation and cracking effects on oil, which significantly reduces the possibility of processing heavy oil and the efficiency of obtaining light products, as well as increased catalyst consumption.

Disclosure of invention

The technical result of the claimed invention is to reduce energy consumption, expand the ability to process heavy oil, increase the efficiency of producing light products, reduce catalyst consumption, improve the economic performance of heavy oil processing, increase the yield of target products.

The technical result is achieved by the fact that the method of catalytic conversion of hydrocarbon feedstock involves contacting a hydrocarbon feed converter with a regenerated catalyst to produce cracked products and a coked catalyst, burning coke from a coked catalyst to produce a regenerated catalyst and exhaust gases, and superheating the water vapor by exchanging water steam with exhaust gases, while the production of cracking products is carried out in the presence of hydrogen-containing of gas heated by the exhaust gases.

In a preferred embodiment, the production of hydrogen-containing gas is carried out by steam catalytic reforming, which is carried out by supplying superheated water vapor and methane-containing gases heated by thermal energy from an external energy source in which nuclear and / or organic fuel is burned. Associated petroleum gas or refinery gases are used as raw materials for producing hydrogen-containing gas. Feed water to produce superheated water vapor is supplied from a reservoir replenished with condensate released from the conversion products. The temperature regime of the catalytic conversion in the converter is maintained by changing the flow rate and composition of the hydrogen-containing gas. The hydrogen-containing gas is supplied periodically, feeding the regenerated catalyst at intervals in the converter. The catalytic conversion of hydrocarbon feed in the converter is carried out in the fluidized bed of the regenerated catalyst at a temperature of from 400 to 650 ° C and at a pressure of from 100 to 5000 kPa in the presence of a zeolite-containing catalyst. As hydrocarbon feedstocks, heavy, superheavy or extra-viscous oils, natural bitumen or oil residues are used, for example: atmospheric distillation residues and products based on them or with their content; vacuum distillation residues and products based on them or with their contents, or residues of the visbreaking process.

Brief Description of the Drawings

The features and essence of the claimed invention are explained in the following detailed description, illustrated by the drawing, which shows the following:

The drawing shows a diagram of the implementation of the method, where

1 - hydrocarbon feed;

2 - converter;

3 - heated hydrogen containing gas;

4 - regenerated catalyst;

5 - cracking products;

6 - cracking gases;

7 - regenerator;

8 - air supply;

9 - exhaust gases;

10 - heater;

11 - feed water;

12 - superheated water vapor;

13 - mixer;

14 - methane-containing gases;

15 - steam-gas mixture;

16 - reformer;

17 - coolant;

18 - energy source.

The implementation and examples of implementation of the invention

An example implementation of the invention is the method of developing a heavy oil reservoir, described below.

In the described example embodiment of the invention, heavy oils are used as hydrocarbon raw materials, and refinery gases are used as methane-containing gases.

The method is as follows.

The hydrocarbon feed 1 is fed to a converter 2, into which a heated hydrogen-containing gas 3 and a regenerated catalyst 4 are also fed from below. In a converter 2, the hydrocarbon feed 1 is contacted with the regenerated catalyst 4 to obtain cracking products 5, cracking gases 6 and coked catalyst, which are removed from Converter 2 and served in the regenerator 7, which simultaneously supply air 8. In the regenerator 7, coke is burned from the coked catalyst to obtain a regenerated catalyst 4 and exhaust gas 9, which is sent to the heater 10, where the thermal energy of the exhaust gas 9 is transferred to the feed water 11 to produce superheated water vapor 12, sent to the mixer 13, which also contains methane-containing gases 14 with the formation of gas-vapor mixture 15, sent to the reformer 16, in which steam catalytic reforming is carried out by supplying heat using a coolant 17 from an energy source 18, in which nuclear and / or organic fuel is burned. As a result of steam catalytic reforming in reformer 16, heated hydrogen-containing gas 3 is obtained, which is sent for additional heating to heater 10, and then fed to converter 2. Feed water 11 is mixed with condensate from cracking products 5 to obtain superheated water vapor 12.

The temperature regime of conversion in converter 2 is supported by changing the flow rate and composition of the heated hydrogen-containing gas 3, which can be supplied periodically by feeding regenerated catalyst 4 at intervals in the converter 2. The catalytic conversion of hydrocarbon feeds is carried out in converter 2 in a fluidized bed of regenerated catalyst 4 at a temperature of 400 up to 650 ° C and at a pressure of 100 to 5000 kPa (1 to 50 bar) in the presence of a zeolite-containing catalyst.

Below are the results of the calculation of the technology for producing heated hydrogen-containing gas 3 in accordance with the above method.

Refinery gases are used as methane-containing gases 14, the steam catalytic reforming of which is carried out in a mixture with superheated water vapor 12 and thermal energy from a heat carrier 17 heated from an external energy source 18, in which nuclear and / or organic fuel is burned.

As products of the catalytic conversion of hydrocarbon feedstocks 1 in the converter 2 are formed cracking products 5 and cracking gases 6, the total composition of which is given in table 1 in mass. %

In addition to cracking gases 6, refinery gases are also formed in other oil refining processes, which are usually part of the complex, which is reflected in the data in Table 2, which shows the composition of hydrocarbon gases in oil refining processes, mol%. [cm. Cracking of oil fractions on zeolite-containing catalysts. Under. ed. S.N. Khadzhieva. M .: Chemistry, 1982].

A mixture of refinery gases [http://monomers-book.ru/book/3-1] formed at a modern refinery, as a rule, has the composition shown in table 3 (in mol.%):

Hydrogen sulfide must be removed before reforming, since it serves as a poison for the catalyst. It is desirable to distinguish propylene and ethylene as well as those subject to further petrochemical processing.

In the table. 4 shows the yield and composition of gases in various oil refining processes [http://monomers-book.ru/book/3-1].

In the calculations, the composition of methane-containing gases 14 is given in Table 5.

The calculation was carried out for a technology productivity of 1000 m3 / h of hydrogen-containing gas 3.

Thus, as shown by calculations, out of 603 m3 / h of methane-containing gases 14 in this method, 1017 m3 / h of hydrogen-containing gas 3 is produced, which is sent to converter 2 for the catalytic conversion of heavy oil. At the same time, in the composition of the hydrogen-containing gas 3, 2128 m3 / h of water vapor, 472 m3 / h of methane, 429 m3 / h of hydrogen, 102 m3 / h of carbon dioxide are supplied to the converter 2.

Due to the high concentration of hydrogen in the hydrogen-containing gas 3 and the high temperature, the hydrocarbon feed stream 1 is subjected to soft non-catalytic (for example, thermal and / or thermomechanical) cracking or visbreaking.

Mercaptans, sulfides and disulfides can be removed with hydrogen in a preliminary hydrotreatment. These compounds are easily hydrogenated under relatively mild conditions. In cyclic organosulfur compounds, under the influence of hydrogen, saturation occurs, followed by ring breaking and the formation of the corresponding paraffinic or alkyl aromatic hydrocarbon.

Oxygen-containing organic compounds usually easily enter into hydrogenation reactions with the formation of the corresponding hydrocarbons and water. Complex resinous and asphaltene substances of oil and oil residues contain a lot of oxygen and therefore their conversion into hydrocarbon products is much more difficult. Of the oxygen-containing compounds, the most important are resins and asphaltenes, which, when hydrogenated, turn into lower molecular weight hydrocarbons and water. In addition to these compounds, phenols and naphthenic acids may be present in different raw materials, during the hydrogenation of which the corresponding hydrocarbons and water are formed.

Destructive hydrogenation is a one- or multi-stage catalytic process of hydrogen addition under pressure, accompanied by the splitting of high molecular weight components of the feed and the formation of low molecular weight hydrocarbons. Non-destructive hydrogenation is a one-stage catalytic process to which all types of distillate feedstock can undergo. As a result, they, without being subjected to cleavage, improve their properties: they are mainly freed from unsaturated hydrocarbons.

This allows you to reduce the need for hydrogen in the processing of hydrocarbons 1 by the proposed method and in general to reduce the cost of oil refining, since the proportion of the cost of producing hydrogen in the total cost of oil refining reaches 30-40%.

Also, according to this method, in the composition of the hydrogen-containing gas 3, 2128 m3 / h of water vapor with a temperature of from 500 ° C to 800 ° C is supplied to the converter 2. This temperature of superheated water vapor reduces the formation of short-chain hydrocarbons and increases the energy costs of the process, and also leads to a decrease in coke formation, which, on the one hand, increases the yield of target cracking products 5, but, on the other hand, reduces the energy output during coke burning during regeneration catalyst supplied to the regenerator 7. This, in turn, leads to a decrease in the volume of exhaust gases 9. Thus, the energy requirements of the process to a lesser extent are covered by hydrocarbon raw materials 1, which required the involvement of a third-party energy source 18.

The converter 2 for processing hydrocarbon feedstock 1 by a catalytic method is a capacitive apparatus with either a dense or moving bed of a large-spherical cracking catalyst or a fluidized bed of a microspherical cracking catalyst arranged inside it, in which the processed feed is contacted with the catalyst and a cleavage reaction occurs hydrocarbon molecules when using catalysts (platinum group metals, transition or heavy metal oxides, aluminosilicate, zeolite-containing and other types of catalysts), which achieves the maximum efficiency of the method, that is, a high degree of processing of raw materials, namely, a high degree of reduction in the average molecular weight of the raw material.

Moreover, due to the supply of hydrogen-containing gas 3, sent to the converter 2 for catalytic conversion of heavy oil by mixing the flows of hydrocarbon raw materials 1 and heated hydrogen-containing gas 3, uneven overheating of the hydrocarbon raw material 1 is eliminated, as is the case, for example, in the process of visbreaking or other known methods cracking, based on the supply of thermal energy through a heat exchange surface, for example, the walls of the tubes.

Unreacted hydrogen and / or light hydrogen-containing media can be separated from the gaseous and / or light portion of the cracking gases 6, which are returned to the mixer 13 for recycling.

The use according to the proposed technology of supplying a hydrogen-containing gas 3 with a high content of steam and hydrogen to the converter 2, as shown by the research results, creates this composition a high dissolving ability in relation to heavy oils, the ability to reduce interfacial tension at the interface "heavy oil - hydrogen-containing gas 3" low corrosion activity in relation to oil equipment, lack of sedimentation of asphalt-resinous substances of heavy oils, the ability to reduce the stability of reagent guide mixture in the converter 2.

Moreover, in the “heavy oil” hydrogenation zone, the hydrogenation of organic compounds may be accompanied by undesirable Fischer-Tropsch side reactions:

The presence of CO - carbon monoxide during the hydrogenation reaction can lead to an excessive consumption of hydrogen and the generation of excess heat, as well as to the synthesis of soot, and this is a significant disadvantage of the method. As a result of steam catalytic reforming in the reformer 16 receive hydrogen-containing gas 3, which contains less than 1% CO.

A stream of oxygen-containing gas, for example, air 8, is introduced into the catalyst regenerator 7 to contact the coked catalyst and burn the coke deposited on it, resulting in a regenerated catalyst and exhaust gases 9, which are supplied at a temperature of 600-900 ° C to the heater 10.

Since coke formation increases significantly with increasing pressure, the coke yield is reduced by diluting the hydrogen-containing gas 3 sent to the converter 2 with water vapor, which is especially important when processing heavy oil feedstocks.

Adopted in the example, the composition of the hydrogen-containing gas 3 shown in table 5, allows to reduce the wear of the ceramic catalyst, by reducing the frequency of circulation of the catalyst. The fact is that the composition of the hydrogen-containing gas 3 allows you to maintain the heat balance of the process, stabilize the operation of the converter 2 and provide the necessary technical and economic indicators. The amount of circulating catalyst in plants of large unit capacity is very large, for example, in a plant with a capacity of 2 million tons / year of processed raw materials - from 1000 to 1500 tons / h. The process of catalytic conversion of hydrocarbon feedstocks can be carried out both with the absorption of heat (breaking C – C bonds) and with its release (eg, hydrogenation, isomerization, alkylation, cyclization). The total thermal effect is determined both by the characteristics of the catalyst and raw materials, and by the partial pressure of hydrogen in the composition of the hydrogen-containing gas 3 and the degree of its conversion. In the traditional process, all the heat necessary for carrying out the process is released during coke burning from the catalyst surface [Cracking of oil fractions on zeolite-containing catalysts. Under. ed. S.N. Khadzhieva. M, Chemistry, 1982]. In the proposed method, due to hydrogen in the composition of the hydrogen-containing gas 3, the heat balance is regulated and can be reduced to the desired minimum.

As hydrocarbon feedstocks, heavy and superheavy oils, super-viscous oils, natural bitumen, and oil residues, such as atmospheric distillation residues and products based on them or containing them, vacuum distillation residues and products based on them or containing them, process residues, are used as hydrocarbon residues. visbreaking. Residues of atmospheric and vacuum distillation of oil - fuel oil and tars, extracts of oil production, asphalt deasphalting are similar in their properties to what is described in the description as “heavy oil”. Thus, the method allows catalytic conversion of atmospheric residues (which boil at a temperature above 343 ° C), as well as heavy vacuum residues (for example, with a boiling point above 566 ° C) and vacuum gas oil (with a nominal boiling point from 343 to 566 ° C), what achieves the maximum efficiency of the method, that is, a high degree of processing of raw materials, namely, a high degree of decrease in the average molecular weight of the raw material. Light vacuum gas oil and medium vacuum gas oil, that is, a mixture of liquid hydrocarbons, mainly with the number of carbon atoms from 10 to 40 (dodecane, decane and others) with a boiling range of 200-500 ° C and a molecular weight of 50-500 g / mol, obtained quality of the product, can be further processed to remove unwanted impurities or processing into other useful hydrocarbon products.

Thus, a method has been created for the catalytic conversion of hydrocarbon feedstocks, in particular heavy oil, in which energy consumption is reduced, the possibilities of processing heavy oil and the efficiency of producing light products are expanded, the consumption of catalyst is reduced, the economic indicators of heavy oil processing are improved, and the yield of target products is increased.

Claims (8)

1. A method for the catalytic conversion of hydrocarbon feedstock, comprising contacting a hydrocarbon feedstock in a fluidized bed converter with a regenerated catalyst to produce cracked products and a coked catalyst, burning coke from a coked catalyst to produce a regenerated catalyst and exhaust gases, overheating water vapor by heat exchange of water vapor with exhaust gases to produce superheated water vapor, characterized in that the production of cracking products in FLS in the presence of hydrogen-containing gas, obtaining a hydrogen-containing gas is carried out by catalytic steam reforming, which is carried out during the approach of said superheated water vapor and methane gas obtained by the hydrogen containing gas is further heated exhaust gases and is fed into the converter. 2. The method according to p. 1, characterized in that the methane-containing gases are heated by thermal energy from an external energy source in which nuclear and / or organic fuel is burned. 3. The method according to p. 1 or 2, characterized in that as a raw material for producing a hydrogen-containing gas, associated petroleum gas or refinery gases are used. 4. The method according to p. 1 or 2, characterized in that the feed water to produce superheated water vapor is supplied from a reservoir replenished with condensate released from the conversion products. 5. The method according to p. 1 or 2, characterized in that the temperature regime of conversion is supported by changing the flow rate and composition of the hydrogen-containing gas. 6. The method according to p. 1 or 2, characterized in that the hydrogen-containing gas is supplied periodically, feeding the regenerated catalyst at intervals in the converter. 7. The method according to p. 1 or 2, characterized in that the catalytic conversion of the hydrocarbon feed in the converter is carried out in the fluidized bed of the regenerated catalyst at a temperature of from 400 to 650 ° C and at a pressure of from 100 to 5000 kPa in the presence of a zeolite-containing catalyst. 8. The method according to p. 1 or 2, characterized in that the hydrocarbon raw materials are heavy and superheavy oils, ultra-viscous oils, natural bitumen and oil residues, such as atmospheric distillation residues and products based on them or with their contents, vacuum residues distillations and products based on them or with their contents, the remains of the visbreaking process.

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