RU2802626C1 - Method and system for treatment of catalytic cracking reaction product and their application - Google Patents

Abstract

FIELD: catalytic cracking.

SUBSTANCE: invention relates to a process for treating a catalytically cracked product, comprising first fractionating catalytically cracked gas oil or catalytically cracked gasoline from a catalytically cracked reactor to produce heavy gasoline and optionally light gasoline, wherein the light gasoline has an initial boiling point of 20-40°C, and a final boiling point of 80-100°C, and heavy gasoline has an initial boiling point of 80-100°C, and a final boiling point of 200-250°C. Carrying out the second fractionation of heavy gasoline to obtain a heavy gasoline fraction and optionally a medium density gasoline fraction, whereas the medium density gasoline fraction comprises light C6-C8 aromatics, has an initial boiling point of 80-100°C, and a final boiling point of 120-150°C, and the fraction of heavy gasoline comprises C9+ aromatic compounds, has an initial boiling point of 120-150°C, and a final boiling point of 200-250°C. Optional implementation of the extraction of aromatic compounds from the fraction of medium density gasoline to obtain aromatic compounds BTX (benzene, toluene, xylene) and aromatic refined oil; directing the heavy gasoline fraction to a fluidized bed reactor and contacting a dealkylation catalyst for dealkylation in the presence of hydrogen to obtain a dealkylated liquid product and a spent dealkylation catalyst; and returning said dealkylated liquid product to step (ii) to carry out a second fractionation of said heavy gasoline. The invention also relates to a catalytic cracking product treatment system, a catalytic cracking system and a catalytic cracking process.

EFFECT: effective conversion of C9+ aromatic compounds comprised in catalytic cracking gas oil and catalytically cracked gasoline into light C6-C8 aromatic compounds, obtaining light olefins with a higher yield, while ensuring long-term stable operation.

18 cl, 14 ex, 5 tbl, 3 dwg

Description

Link to related applications

This application claims priority to Patent Application No. 201911048194.1, entitled "Method and system for treating gasoline by catalytic cracking, method and apparatus for catalytic cracking" and filed on October 30, 2019, the contents of which are incorporated herein by reference in their entirety.

Field of the present invention

This application relates to the field of catalytic cracking, in particular to a method and system for treating the product of a catalytic cracking reaction and to their use.

BACKGROUND OF THE INVENTION

BTX (benzene, toluene and xylene) is an important petrochemical base product and an essential feedstock for a variety of chemical products such as synthetic rubber, synthetic fiber and synthetic resin; In addition, toluene and xylene can be used as additives to increase the octane number of gasoline. Due to the continuous development of industrial production of terylene, polyesters and purified terephthalic acid in China, the growth of the global aromatic hydrocarbon industrial chain is concentrated in the north-eastern regions of Asia, and at the same time the demand for VTX is continuously increasing. However, the processes for producing these aromatic compounds are accompanied by the formation of C9+ aromatic compounds, and currently a very large number of C9+ aromatic compounds are produced, which have low value and limited application, causing waste of resources. Thus, the conversion of C9+ aromatic compounds in catalytically cracked gasoline into VTC, with the associated production of more light olefins, undoubtedly represents an effective path to full utilization of resources and to improving the quality and efficiency of enterprises.

Patent application CN 101362669 A discloses a catalytic conversion process for the production of ethylene, propylene and aromatics, characterized in that it involves the following steps: contacting hydrocarbon feedstocks with a catalytic cracking catalyst under various cracking conditions to carry out the cracking reaction in a reactor with fluidized bed, separation of spent catalyst and reaction gas oil, return of spent catalyst to the reactor after regeneration and separation of reaction gas oil to obtain target products such as light olefins and aromatics, while the fraction with a boiling point of 160-260 ° C is returned to the catalytic cracking reactor for reuse, and ethane, propane and butane are steam cracked to produce ethylene and propylene. This process can produce light olefins such as ethylene, propylene and other olefins from heavy feedstocks in maximum yield and by-products of aromatics such as toluene, xylene and other compounds, and as a result the total yields of ethylene and propylene can be more than 20 wt. %.

Patent application CN 1752058 A discloses a process for hydrodealkylation and transalkylation of heavy aromatic compounds, the main purpose of which is to solve the problems of the prior art, such as the low allowable content of heavy aromatic compounds in the starting materials and the low utilization rate of heavy aromatic compounds. This method solves the above problems by carrying out the reaction in a fixed bed reactor at a temperature of 300-600°C and a pressure of 1.0-4.0 MPa using C10 and/or C11 aromatic compounds as starting material and macroporous zeolite containing metal bismuth and molybdenum or corresponding oxides as a catalyst to produce a mixture of xylene isomers. This method has such characteristics as ease of implementation, high yield of a mixture of xylene isomers, low ratio of hydrogen and hydrocarbons, etc., and can be used for the industrial production of a mixture of xylene isomers from heavy aromatic compounds.

Patent application CN 1906272 A discloses a method for the separate catalytic hydrodealkylation of hydrocarbons containing C8-C13 alkylaromatic compounds, with which aliphatic and cycloaliphatic C4-C9 products are optionally mixed, and the method provides for continuous processing of the hydrocarbon composition using a catalyst consisting of ZSM-5 zeolite and modified with at least one metal selected from metals of group IIB, group VIB and group VIII, in the presence of hydrogen at a temperature of 400-650°C, a pressure of 2-4 MPa and a molar ratio of hydrogen to starting material of from 3 to 6. This method can provide a complete yield of benzene and toluene up to 75%.

Patent application CN 101348733 A discloses a process for producing light aromatics and light paraffins from hydrocarbon starting materials, which involves the following steps: reacting a hydrocarbon starting material having a boiling point of 30 to 250° C. in the presence of a zeolite catalyst containing Pt or Pd, introducing heavy aromatics into the hydrocarbon feedstock in hydrodealkylation and transalkylation reactions with light aromatics, introducing light aromatics into an isomerization reaction to convert them into a component enriched in light aromatics BTX (B is benzene, T is toluene , and X is xylene), introducing non-aromatic compounds into a hydrocracking reaction to produce light waxes, separating liquid products into benzene, toluene, xylene and C9+ aromatics according to different boiling points in a distillation column, and separating light waxes from gaseous products. This method overcomes the problems that are present in traditional methods for separating hydrocarbon feedstocks, such as the need for solvent extraction, process complexity, high cost and low value of heavy aromatics and non-aromatics resulting from the separation.

Patent application CN 101734986 A discloses a method for increasing the yield of benzene and xylene by hydrocracking the cracked gasoline. This method provides for the reaction of the starting material, which is C7+ cracking gasoline, in the presence of a catalyst, the introduction of heavy aromatic compounds into hydrodealkylation and transalkylation reactions with light aromatic compounds, the introduction of light aromatic compounds into an isomerization reaction in order to convert them into a component with a high light content aromatic BTX compounds, separation of liquid products into benzene, toluene, xylene and C9+ fraction according to different boiling points, while toluene and C9+ fraction can be returned for further processing, and separation of light paraffins from gaseous products. This method solves the problems that are present in traditional methods of processing cracked gasoline and represent only the separation of aromatic compounds BTX (B is benzene, T is toluene, and X is xylene), and the light aromatic product has a high toluene content, and the separated heavy aromatic compounds and non-aromatic compounds are of low value.

Patent application CN 103930524 A discloses a process for converting biomass into products, which involves the following steps: contacting the biomass with hydrogen in the presence of a hydropyrolysis catalyst in a fluidized bed reaction vessel under hydropyrolysis conditions; and removing products and carbon from the reaction vessel, wherein carbon and catalyst are separated according to different deposition rates.

The methods disclosed in the patent applications listed above demonstrate that existing technologies for upgrading heavy aromatics rely primarily on fixed-bed hydrodealkylation processes and are disadvantaged by stringent reaction conditions, operational difficulties, and stringent catalyst requirements.

Brief Disclosure of the Present Invention

It is an object of the present invention to provide a method and system for treating catalytic cracking products such that the method can effectively convert C9+ aromatics contained in catalytic cracked gas oil and catalytic cracked gasoline into light C6-C8 aromatics. , and light olefins could be produced in higher yields while ensuring long-term sustainable operation.

To solve the above problem, according to this application, a method for processing a catalytic cracking product is proposed, which involves the following stages:

i) performing a first fractionation of the catalytic cracked gas oil or catalytic cracked gasoline from the catalytic cracking reactor to produce heavy gasoline and optionally light gasoline, wherein the light gasoline has an initial boiling point of approximately 20-40° C. and a final boiling point of approximately 80 -100°C, and heavy gasoline has an initial boiling point of approximately 80-100°C and a final boiling point of approximately 200-250°C;

ii) carrying out a second fractionation of the heavy gasoline to obtain a heavy gasoline fraction and optionally a medium density gasoline fraction, wherein the medium density gasoline fraction contains light C6-C8 aromatics, has an initial boiling point of approximately 80-100° C. and a final boiling point , which is approximately 120-150°C, and the heavy gasoline fraction contains C9+ aromatic compounds, and has an initial boiling point of approximately 120-150°C, and a final boiling point of approximately 200-250°C;

iii) optionally extracting aromatics from the medium-gravity gasoline fraction to produce BTX aromatics and an aromatic refined petroleum product;

iv) sending the heavy gasoline fraction into a fluidized bed reactor and contacting it with a dealkylation catalyst for dealkylation in the presence of hydrogen to produce a dealkylated liquid product and a spent dealkylation catalyst; And

v) returning said dealkylated liquid product to step (ii) to carry out a second fractionation of said heavy gasoline.

According to another aspect of the present invention, there is provided a catalytic cracking process comprising the following steps:

a) contacting a hydrocarbon-containing petroleum feedstock with a catalytic cracking catalyst in a catalytic cracking reactor for a catalytic cracking reaction to produce catalytic cracking gas oil; And

b) treating the catalytic cracking gas oil using the catalytic cracking product treatment method of the present application.

According to another aspect of the present invention, there is provided a catalytic cracking product processing system comprising a catalytic cracking product inlet, a first separation unit, a second separation unit, a dealkylation unit, and an optional aromatic extraction unit;

wherein the first separation unit comprises a first separator, the first separator comprising a first gas oil inlet, a light gasoline outlet, a heavy gasoline outlet, and optionally one or more other product outlets, wherein the first gas oil inlet is in communication with the catalytic cracking product inlet, and optionally the light gasoline outlet is in communication with the feed inlet of the catalytic cracking reactor;

the second separation unit includes a distillate separation column, the distillate separation column contains a second gas oil inlet, a medium density gasoline fraction outlet, and a heavy gasoline fraction outlet, and the second gas oil inlet is in communication with the heavy gasoline outlet;

the aromatic compounds extraction unit contains a device for extracting and separating aromatic compounds, the device for extracting and separating aromatic compounds contains a third gas oil inlet, an outlet for aromatic compounds VTX and an outlet for an aromatic refined petroleum product, the third gas oil inlet is in communication with the outlet of the medium density gasoline fraction, and optionally an aromatic outlet the refined petroleum product is in communication with the feed inlet of the catalytic cracking reactor;

The dealkylation unit comprises a fluidized bed reactor, the fluidized bed reactor contains a fourth gas oil inlet and a gas oil outlet, the fourth gas oil inlet is in communication with the heavy fraction gasoline outlet of the distillate separation column, and the gas oil outlet is in communication with the second gas oil inlet of the distillate separation column.

According to another aspect of the present invention, there is provided a catalytic cracking system comprising a catalytic cracking unit and a catalytic cracking product processing system according to the present application, wherein the catalytic cracking unit comprises a catalytic cracking reactor and optionally a catalytic cracking catalyst regenerator, the gas oil outlet of the catalytic cracking reactor is in communication with the inlet the catalytic cracking product of the catalytic cracking product treatment system, the catalytic cracking reactor feed inlet is in communication with the light gasoline outlet, and/or the catalytic cracking reactor feed inlet is in communication with the aromatic refined petroleum product outlet.

The method and system according to the present application uses a fluidized reaction system to carry out hydrodealkylating treatment of heavy aromatic compounds that are present in catalytic cracking products, and as a result, the heavy aromatic compounds can be efficiently converted into light olefins and light aromatic compounds, and the yield of light aromatics connections may be increased. In addition, the method further provides the advantages of catalyst regeneration, convenient implementation and operation, and long-term sustainable operation.

Additional features of the advantages of the present invention will be described in detail below in the detailed disclosure section of this document.

Brief description of the figures

The figures which form part of the present description are presented to facilitate understanding of the present invention and should not be construed as limiting. This application may be construed by reference to the figures in conjunction with the following detailed disclosure section herein. Among the figures:

in fig. 1 is a flow diagram of a catalytic cracking process according to a preferred embodiment of the present invention;

in fig. 2 is a schematic diagram of a catalytic cracking unit of a catalytic cracking system according to a preferred embodiment of the present invention;

in fig. 3 is a schematic diagram of a dealkylation unit of a catalytic cracking system according to a preferred embodiment of the present invention.

Detailed Disclosure of the Present Invention

The present invention will be described in detail hereinafter by presenting specific embodiments and accompanying figures. It should be noted that specific embodiments of the present invention are presented for illustrative purposes only and are not intended to be limiting in any way.

Any particular numerical value, including the endpoints of numerical ranges, described in the context of this application is not limited to the corresponding exact value, but should be construed to further cover all values in the vicinity of the specified precise value, such as any possible values within ±5% of the exact value. Moreover, with respect to any numerical range described herein, arbitrary combinations may be made between the endpoints of the range, between each endpoint and any particular value within the range, or between any two particular values within the range to obtain one or more new numerical ranges, and one or more of these new numerical ranges should also be considered as specifically described in this application.

Unless otherwise stated, terms used herein have the meanings commonly understood by those skilled in the art; and to the extent that terms are defined herein and their definitions differ from those generally understood in the art, then the definitions set forth herein shall prevail.

As used herein, the term “C9+ aromatic compounds” is a general term for aromatic compounds containing nine or more carbon atoms, which is intended to cover any existing aromatic compound containing 9 or more than 9 carbon atoms. Likewise, as used herein, the term “C12+ aromatic compounds” is a general term for aromatic compounds containing twelve or more than twelve carbon atoms, which is intended to cover any existing aromatic compound containing 12 or more than 12 carbon atoms.

As used herein, the term “C6-C8 light aromatic compounds” is a general term for aromatic compounds containing six to eight carbon atoms, which is intended to cover any existing aromatic compound containing 6, 7, or 8 carbon atoms.

In this application, the terms "fluidized bed reactor" and "fluidized reactor" are used interchangeably and mean a reactor in which solid catalyst particles are brought into slurry state by a gas process stream to carry out a gaseous-solid reaction process, and are provided for in various forms of suspended conductive layers, dense phase conductive layers, bubbling fluidized beds, turbulent fluidized beds, high-speed fluidized beds, etc.

In the context of the present application, in addition to what is expressly expressed, any object or objects that have not been mentioned should be considered to be the same as those already known in the art, without any modification. In addition, any of the embodiments that are described herein may be optionally combined with one or more other embodiments that are described herein, and the resulting techniques or ideas should be considered part of the original disclosure or initial descriptions of the present invention, and should not be construed as new subject matter that has not been described or contemplated herein unless it is clear and obvious to those skilled in the art that such combination is unreasonable.

All patent and non-patent documents cited herein, including, but not limited to, textbooks and journal articles, are incorporated herein by reference in their entirety.

According to a first aspect of the present invention, there is provided a method for treating a catalytic cracking product, comprising the following steps:

i) performing a first fractionation of the catalytic cracking gas oil and/or catalytic cracking gasoline from the catalytic cracking reactor to produce heavy gasoline and optionally light gasoline;

ii) performing a second fractionation of the heavy gasoline to obtain a heavy gasoline fraction and optionally a medium-density gasoline fraction, wherein the medium-gravity gasoline fraction contains light C6-C8 aromatics and the heavy gasoline fraction contains C9+ aromatics;

iii) optionally extracting aromatics from the medium-gravity gasoline fraction to produce BTX aromatics and an aromatic refined petroleum product;

iv) sending the heavy gasoline fraction into a fluidized bed reactor and contacting it with a dealkylation catalyst for dealkylation in the presence of hydrogen to produce a dealkylated liquid product and a spent dealkylation catalyst; And

v) returning said dealkylated liquid product to step (ii) to carry out a second fractionation of said heavy gasoline.

The method according to the present application can effectively convert heavy aromatic compounds contained in the catalytic cracking product into light olefins and light aromatic compounds, improve the yield of light olefins, and also ensure long-term stable operation.

According to the present application, the catalytic cracking product to be processed and supplied from the catalytic cracking reactor may be a gas oil obtained from the catalytic cracking reaction and/or a catalytic cracking gasoline obtained by separating the gas oil.

According to the present application, the apparatus and process conditions for the first fractionation in step (i) are not particularly limited, for example, the apparatus for the first fractionation may be a fractionation column or a flash drum, and the conditions for the first fractionation may be those which are conventionally used in technology. In a preferred embodiment, the first fractionation in step (i) produces light gasoline and heavy gasoline, said light gasoline having an initial boiling point of approximately 20-40°C and a final boiling point of approximately 80-100°C ; Heavy gasoline has an initial boiling point of approximately 80-100°C and a final boiling point of approximately 200-250°C.

According to the present application, the light gasoline obtained from the first fractionation in step (i) may contain olefins containing from 5 to 8 carbon atoms, while the resulting heavy gasoline contains mainly aromatic and non-aromatic components containing from 6 to 11 carbon atoms. According to the present application, the first fractionation in step (i) may optionally further produce other products such as light olefins, C12+ aromatics and non-aromatic components, the light olefins being primarily olefins containing from 2 to 4 carbon atoms .

In order to further increase the yield of light olefins according to a preferred embodiment, as illustrated in FIG. 1, the light gasoline obtained from the first fractionation can be returned to the catalytic cracking reactor for subsequent catalytic cracking reaction. In addition, the catalytic cracking reactor preferably contains an upflow reactor and a fluidized bed reactor, and light gasoline can be returned to the catalytic cracking reactor without any position restriction, i.e. it can be returned to an upflow reactor or a fluidized bed reactor.

According to the present application, the apparatus and conditions for the second fractionation in step (ii) are not particularly limited, for example, the apparatus for the second fractionation may be a fractionation column, and the conditions for the second fractionation may be those which are conventionally used in the art. In a preferred embodiment, the second fractionation in step (ii) produces a mid-grade gasoline fraction and a heavy gasoline fraction, wherein the medium-gravity gasoline fraction has an initial boiling point of approximately 80-100° C. and a final boiling point of approximately 120-120° C. 150°C; and the heavy gasoline fraction has an initial boiling point of approximately 120-150°C and a final boiling point of approximately 200-250°C.

According to the present application, the medium density gasoline fraction obtained as a result of the second fractionation in step (ii) contains mainly BTX aromatic compounds, while the resulting heavy gasoline fraction contains mainly C9+ aromatic compounds, as well as non-aromatic components, such as naphthenes and paraffins.

According to the present application, in step (iii), the medium gravity gasoline fraction may be subjected to aromatic extraction to further separate light aromatics such as benzene, toluene and xylene. According to the present application, the apparatus and conditions for extracting aromatic compounds in step (iii) are not particularly limited, for example, the apparatus for extracting aromatic compounds may comprise an extraction column, a solvent recovery column, and an aromatic separation column, and the extraction agent used may be a substance which is traditionally used in the art, such as sulfolane, tetraethylene glycol ether, diethylene glycol ether, N-methylpyrrolidone, and the types and operating conditions of the extraction column, solvent recovery column and aromatic separation column may be the same as the types and conditions that are traditionally are used in technology, and a detailed description of which is not presented in this document.

According to the present application, the aromatic refined petroleum product resulting from the extraction of aromatic compounds in step (iii) contains non-aromatic components. To further increase the yield of light olefins, in a preferred embodiment, the aromatic refined petroleum product may be returned to the catalytic cracking reactor for subsequent catalytic cracking reaction.

According to the present application, in step (iv), the heavy gasoline fraction containing C9+ aromatics can be sent to a fluidized bed reactor in the presence of hydrogen and contacted with a dealkylation catalyst for dealkylation, whereby the C9+ aromatics are cracked and dealkylated, and a dealkylation product and a spent dealkylation catalyst are formed, wherein the dealkylation product can be subjected to gas-liquid phase separation to produce a dealkylated liquid product and hydrogen.

According to the present application, the conditions for dealkylation of the heavy gasoline fraction in the fluidized bed reactor can vary widely, and according to a preferred embodiment, the reaction temperature can be about 250-700°C, preferably about 320-580°C, more preferably about 350-550°C C, including about 380-500°C or about 400-480°C; the pressure (gauge pressure) may be from about 0 to about 6 MPa, preferably from about 0.1 to about 4.5 MPa, more preferably from about 1 to about 3.5 MPa; the hourly average mass-volume feed rate (eg, for a dense phase fluidized bed) can be from about 0.1 to about 120 h ^-1 , preferably from about 0.5 to about 80 h ^-1 , more preferably from about 1.5 to about 50 h ^-1 , including about 1 to about 30 h ^-1 , about 1.5 to about 15 h ^-1 , about 1 to about 10 h ^-1 , or about 1.5 to about 10 h ^-1 , or the reaction duration (for example, for a moving bed reactor) may be from about 0.1 to about 40 seconds, preferably from about 0.5 to about 30 seconds, preferably from about 1 to about 15 seconds, including from about 0.2 to about 20 seconds, or from about 0.6 to about 10 seconds; the molar ratio of hydrogen to hydrocarbons can be from about 1 to about 14, preferably from about 2 to about 11, and more preferably from about 3 to about 6.

According to the present application, the dealkylation catalyst used in the dealkylation reaction may contain a support and an active metal component supported on the support, and the composition and content of the dealkylation catalyst may vary within wide limits. In a preferred embodiment, based on the total weight of the dealkylation catalyst, the support may be present in the dealkylation catalyst in an amount ranging from about 50 to about 99.99 weight percent. %, preferably from about 55 to about 85 wt. %; and the active metal component may be present in an amount of from about 0.01 to about 50 wt. %, preferably from about 0.01 to about 45 wt. %.

According to the present application, the active metal component is preferably one or more rare earth metals and transition metals such as Fe, Ni, Pt, Pd, Co and Mo, preferably Ni, Pt and Pd. When the active metal component is a noble metal, it is preferably present in an amount of from about 0.01 to about 5 wt. %; and when the active metal component is a base metal, it is preferably present in an amount of from about 0.01 to about 30 wt. %, based on metal elements and relative to the total weight of the dealkylation catalyst.

According to the present application, when the active metal component is a noble metal, the dealkylation catalyst does not necessarily need to be pre-sulfided; and when the active metal component is a base metal, the dealkylation catalyst may or may not be presulfided.

According to the present application, the composition and content of the carrier can also vary widely. According to a preferred embodiment, the carrier may contain from about 1 to about 80 wt. % zeolite, from about 5 to about 99 wt. % inorganic oxide and from about 0 to about 70 wt. % clay, relative to the dry weight of the carrier; preferably, the carrier may contain from about 10 to about 50 wt. % zeolite, from about 10 to about 90 wt. % inorganic oxide and from about 1 to about 60 wt. % clay.

According to a further preferred embodiment, the zeolite may be a mesoporous zeolite, a macroporous zeolite, or a corresponding combination, and is preferably selected from the group consisting of a mesoporous zeolite, a macroporous zeolite, and a corresponding combination. More preferably, relative to the total weight of the zeolite, the mesoporous zeolite is present in an amount of from about 0 to about 100 wt. %, preferably from about 50 to about 100 wt. %, preferably from about 70 to about 90 wt. %; the macroporous zeolite is present in an amount ranging from about 0 to about 100 wt. %, preferably about 0 to about 50 wt. %, preferably from about 10 to about 30 wt. %.

According to the present application, in the dealkylation catalyst support, mesoporous and macroporous zeolites may be of the types that are conventionally used in the art, wherein the mesoporous zeolite is preferably one or more zeolites selected from ZSM zeolites and ZRP zeolites, and the macroporous zeolite is preferably one or more than one zeolite selected from P zeolites, REY zeolites, REHY zeolites, ultra-stable Y zeolites and high silica content Y zeolites.

According to the present application, in the dealkylation catalyst support, the inorganic oxide and the clay may in each case be of a type that is conventionally used in the art, for example, the inorganic oxide may be one or more oxides, such as silica, alumina, zirconia , titanium dioxide and amorphous silica aluminum oxide, preferably silica and/or alumina; the clay may be one or more minerals, such as kaolin, montmorillonite, diatomite, attapulgite, sepiolite, halloysite, hydrotalcite, bentonite and rectorite, preferably kaolin and/or halloysite.

According to the present application, the dealkylation catalyst can be manufactured by a method that is conventionally used in the art, for example, by applying the active metal component to the above-mentioned support in a process of impregnation and saturation of the pores.

According to the present application, the carrier can be subjected to hydrothermal aging by treatment under the following conditions: the temperature is from about 700°C to about 850°C and the atmosphere contains up to 100% steam, or the carrier can be used without hydrothermal aging.

According to the present application, the dealkylation catalyst is preferably present in the form of microspheroidal particles having the following particle size distribution: the mass fraction of particles with sizes from 0 to 20 μm is less than about 5%, the mass fraction of particles with sizes from 0 to 40 μm is less than about 30%, the mass fraction of particles with sizes from 0 to 149 μm is more than about 80%, and the average particle size is about 50 to about 90 μm, preferably from about 60 to about 80 μm; and the catalyst abrasion index is less than 10%/hour and preferably 5%/hour.

According to the present application, separation of the spent dealkylation catalyst from the dealkylation product obtained in step (iv) can be accomplished using cyclones, which are well known to those skilled in the art, or using filters, which are well known to those skilled in the art. The separated spent dealkylation catalyst may be sent to a dealkylation catalyst regenerator for regeneration and then returned.

According to the present application, the dealkylation catalyst regenerator used may be of the type that is conventionally used in the art. In a preferred embodiment, the spent dealkylation catalyst may be sent to a fluidized bed regenerator for regeneration, and the resulting regenerated dealkylation catalyst may be returned to the fluidized bed reactor, preferably all or at least a portion of the dealkylation catalyst used in step (iv). ), produced from regenerated dealkylation catalyst. According to the present application, regeneration of the spent dealkylation catalyst can be carried out in a manner that is well known to those skilled in the art, and during the regeneration process, oxygen-containing gas, such as air, can generally be introduced into the regenerator from the bottom thereof. After being introduced into the regenerator, the spent dealkylation catalyst is contacted with oxygen for regeneration by decoking, the off-gas that is generated from the regeneration of the catalyst is subjected to gas-solid separation at the top of the regenerator and then passed to the subsequent energy recovery system. Depending on the properties of the active metal component of the catalyst, regeneration methods such as reduction and sulfurization can be used.

In order to prevent contact between the hydrogen-containing gas stream and the oxygen-containing gas stream during the catalyst regeneration process and improve the safety level of the installation, according to a preferred embodiment, as illustrated in FIG. 3, the fluidized bed regenerator may further comprise a seal hopper, and the regeneration method may be provided with: passing the spent dealkylation catalyst through the seal hopper into the fluidized bed regenerator for regeneration, and returning the regenerated dealkylation catalyst to the fluidized bed reactor through the seal hopper. In this embodiment, the seal hopper allows the dealkylation catalyst to be safely and efficiently transferred from a high hydrocarbon or hydrogen pressure atmosphere in the reactor to a low oxygen pressure atmosphere in the regenerator and from a low oxygen pressure atmosphere in the regenerator to a high hydrocarbon or hydrogen pressure atmosphere in the reactor . According to a preferred embodiment of the present invention, the method further includes the steps of reducing the pressure for the spent catalyst and then increasing the pressure for the regenerated catalyst in the seal hopper.

According to the present application, by using a seal hopper, the reducing atmosphere (hydrogen atmosphere) in the reactor and in the feed tank of the regenerated dealkylation catalyst can be reliably isolated from the oxygen-containing atmosphere in the regenerator for regeneration by decoking, whereby the safety of the method and process can be ensured, and The operating pressure of the reactor and regenerator can be flexibly adjusted and controlled. In particular, the operating pressure of the reactor can be increased without increasing the operating pressure of the regenerator, and as a result, the process capacity of the installation can be increased. The seal hopper described herein is a device that allows the flow to be switched between different atmospheres (for example, between oxidizing and reducing atmospheres) and/or between atmospheres with different pressures (for example, from a high pressure atmosphere to a low pressure atmosphere or vice versa), and the corresponding configuration and operation can be easily accomplished by those skilled in the art based on the disclosure presented herein.

According to a particularly preferred embodiment as illustrated in FIG. 3, the fluidized bed regenerator may further comprise a reactor receiver 28, a regenerator receiver 31, a regenerator feed tank 25, and optionally a reducing agent 32, and the spent dealkylation catalyst that is discharged from the fluidized bed reactor may be transferred to the reactor receiver 28, then to the regenerator the feed tank 25 through the seal hopper 29, and then from the regenerator feed tank 25 to the fluidized bed regenerator 30 and subjected to regeneration by burning coke in the regenerator in an oxygen-containing atmosphere to obtain a regenerated dealkylation catalyst; the regenerated dealkylation catalyst is continuously discharged from the fluidized bed regenerator 30, passed into the reducing agent 32 through the regenerative receiver 31 and, after reduction, returned to the fluidized bed reactor for reuse. Even more preferably, the spent dealkylation catalyst may be subjected to pressure reduction in the barrier hopper 20, and the regenerated dealkylation catalyst may be subjected to a pressure increase in the barrier hopper 20, if desired.

According to the present application, the fluidized bed reactor used is preferably selected from the group consisting of a moving bed reactor, a dense phase fluidized bed reactor, a combination reactor that is composed of a moving bed reactor and a dense phase fluidized bed reactor, a combination reactor that is composed of two or more moving bed reactors, or a combination reactor, which consists of two or more dense phase fluidized bed reactors; the moving bed reactor may be, for example, an upflow reactor; and the dense phase fluidized bed reactor may be, for example, a bubble bed reactor, a turbulent bed reactor, etc. According to a preferred embodiment, the fluidized bed reactor used is a dense phase fluidized bed reactor which may comprise at the top an expanded segment in which cyclones or catalyst filters may be provided to recover the catalyst entrained in the gas stream. When a dense phase fluidized bed reactor or an upflow reactor is used, the corresponding loading and operating conditions may be the same as those conventionally adopted in existing dense phase fluidized bed reactors and upflow reactors, and there are no specific restrictions in this regard. in this application.

According to the present application, in step (v), the dealkylated liquid product enriched in light C6-C8 aromatics can be returned to step (ii) and subjected to a second fractionation along with said heavy gasoline to further separate and obtain a medium density gasoline fraction enriched in aromatics VTX, and heavy gasoline fraction enriched with C9+ aromatic compounds.

According to a second aspect of the present invention, there is provided a catalytic cracking process comprising the following steps:

a) contacting the feedstock with a catalytic cracking catalyst in a catalytic cracking reactor to produce a catalytic cracking gas oil; And

b) treating the catalytic cracking gas oil using the catalytic cracking product treatment method of the present application.

According to the present application, the starting petroleum product is not particularly limited and may be, for example, at least one petroleum product, which may be gasoline, diesel fuel, vacuum distillation paraffinic oil, atmospheric distillation paraffinic oil, coking paraffinic oil, deasphalted oil, Vacuum distillation residues, atmospheric distillation residues, extraction oil, low-grade recycle gas oil, coal liquefaction oil, bituminous oil and shale oil.

According to the present application, the catalytic cracking reactor may be of a type that is traditionally used in technology. According to a preferred embodiment, the catalytic cracking reactor comprises a dense phase fluidized bed reactor and an upflow reactor arranged from top to bottom. In embodiments in which the light gasoline is returned to the catalytic cracking reactor, the position to which the light gasoline is returned may be a dense phase fluidized bed reactor or an upflow reactor. In embodiments in which the aromatic refined petroleum is returned to the catalytic cracking reactor, the position to which the aromatic refined petroleum is returned may be a dense phase fluidized bed reactor or an upflow reactor.

According to the present application, the catalytic cracking reaction conditions in step (a) can vary within wide limits. Preferably, according to embodiments in which the catalytic cracking reactor comprises a dense phase fluidized bed reactor and an upflow reactor arranged from top to bottom, the reaction in the upflow reactor can be carried out under the following conditions: the reaction temperature is approximately 550-720°C, the reaction time is approximately 1-10 seconds, the reaction pressure is approximately 130-450 kPa, the ratio of catalyst to petroleum product is approximately 1-100:1; the reaction in a dense phase fluidized bed reactor can be carried out under the following conditions: reaction temperature is approximately 530-730°C, reaction duration is approximately 1-20 seconds, hourly average mass-volume feed rate is approximately 0.5-20 h ^{- 1} , and the ratio of catalyst to petroleum product is approximately 1-100:1.

According to the present application, the catalytic cracking catalyst used in step (a) may be a catalyst that is conventionally used in the art. According to a preferred embodiment, the catalytic cracking catalyst may contain, relative to the total weight of the catalyst, approximately 1-60 wt. % zeolite, approximately 5-99 wt. % inorganic oxide and approximately 0-70 wt. % clay, wherein the zeolite may be a mesoporous zeolite, a macroporous zeolite or a corresponding combination, and is preferably selected from the group consisting of a mesoporous zeolite, a macroporous zeolite and a corresponding combination; more preferably, the mesoporous zeolite may be present in an amount of from about 50 to about 100 wt. %, preferably from about 70 to about 100 wt. %, based on the total weight of the zeolite, and the macroporous zeolite may be present in an amount ranging from about 0 to about 50 wt. %, preferably from about 0 to about 30 wt. %, relative to the total weight of the zeolite. According to the present application, in the catalytic cracking catalyst used, the mesoporous zeolite is preferably one or more zeolites selected from ZSM zeolites and ZRP zeolites, and the macroporous zeolite is preferably one or more zeolites selected from p zeolites, REY zeolites, REHY zeolites, super-resistant Y zeolites and high silica Y zeolites; the inorganic oxide is preferably one or more oxides selected from silica, alumina, zirconia, titanium dioxide and amorphous silica alumina; the clay is preferably one or more minerals selected from kaolin, montmorillonite, diatomite, attapulgite, sepiolite, halloysite, hydrotalcite, bentonite and rectorite.

According to a third aspect of the present invention, there is provided a catalytic cracking product processing system, comprising a catalytic cracking product inlet, a first separation unit, a second separation unit, a dealkylation unit, and optionally an aromatic extraction unit;

wherein the first separation unit comprises a first separator, the first separator includes a first gas oil inlet, a light gasoline outlet, a heavy gasoline outlet, and optionally one or more other product outlets, and the first gas oil inlet is in communication with the catalytic cracking product inlet;

the second separation unit includes a distillate separation column, the distillate separation column contains a second gas oil inlet, a medium density gasoline fraction outlet, and a heavy gasoline fraction outlet, and the second gas oil inlet is in communication with the heavy gasoline outlet;

the aromatic compound extraction unit contains an aromatic compound extraction and separation device, the aromatic compound extraction and separation device contains a third gas oil inlet, a BTX aromatic compound outlet and an aromatic refined petroleum product outlet, and the third gas oil inlet is in communication with the medium density gasoline fraction outlet;

The dealkylation unit comprises a fluidized bed reactor, the fluidized bed reactor contains a fourth gas oil inlet and a gas oil outlet, the fourth gas oil inlet is in communication with the heavy gasoline fraction outlet of the distillate separation column, and the gas oil outlet is in communication with the second gas oil inlet of the distillate separation column.

According to the present application, the light gasoline outlet may optionally be in communication with the feed inlet of the catalytic cracking reactor, and as a result, the light gasoline may be returned to the catalytic cracking reactor for subsequent reaction.

According to the present application, the aromatic refined petroleum outlet may optionally be in communication with the feed inlet of the catalytic cracking reactor, and as a result, the aromatic refined petroleum product can be returned to the catalytic cracking reactor for subsequent reaction.

According to the present application, the first separation unit and the first separator are used for separating light gasoline from heavy gasoline in the composition of catalytic cracked gas oil and catalytic cracked gasoline, and optionally for separating one or more other products such as light olefins, C12+ aromatics and non-aromatic components . The first separator may be a separator that is conventionally used in the art, such as, for example, a fractionator or a flash drum. The first gas oil inlet of the first separator is used for introducing catalytic cracking gas oil and catalytic cracking gasoline.

According to the present application, a second separation unit and a distillate separation column are used to further separate the heavy gasoline obtained from the first separation unit into a middle gasoline fraction and a heavy gasoline fraction. The distillate separation column may be of a type that is conventionally used in the art, such as a fractionating column, for example.

The aromatic extraction unit and the aromatic extraction and separation apparatus are used for separating the BTX aromatic compounds contained in the medium density gasoline fraction obtained by the second separation, and the aromatic extraction and separation apparatus may be a device that is conventionally used in the art . According to a preferred embodiment, the aromatic extraction and separation apparatus may comprise an aromatic extractor, an aromatic separation column, and a solvent regenerator, and the aromatic extractor comprises a third gas oil inlet, a solvent inlet, an aromatic-solvent mixture outlet, and an aromatic refined petroleum outlet; the solvent regenerator includes an aromatic-solvent mixture inlet, an aromatic compound outlet, and a solvent outlet, and wherein the aromatic-solvent mixture inlet is in communication with the aromatic-solvent mixture outlet of the aromatic extractor; the aromatics separation column contains a fifth gas oil inlet and a BTX aromatics outlet, the fifth gas oil inlet is in communication with the aromatics outlet of the solvent regenerator, and the BTX aromatics outlet contains a benzene outlet, a toluene outlet, and a xylene outlet.

According to the present application, the dealkylation unit is used for dealkylation of the heavy gasoline fraction obtained as a result of the second separation in order to convert C9+ aromatic compounds into light C6-C8 aromatic compounds. The fluidized bed reactor used to carry out the dealkylation reaction is not particularly limited, and may be a reactor which is conventionally used in the art, and preferably a moving bed reactor, a dense phase fluidized bed reactor, a combination reactor, which constitute a moving bed reactor and a dense phase fluidized bed reactor, a combination reactor which is constituted by two or more moving bed reactors, or a combination reactor which is constituted by two or more dense phase fluidized bed reactors; wherein the moving bed reactor is preferably an upflow reactor; The dense phase fluidized bed reactor may be a bubble fluidized bed reactor, a turbulent fluidized bed reactor, or the like; The fluidized bed reactor may be an upflow reactor or a downflow reactor.

For the purpose of regenerating the spent catalyst, the dealkylation unit preferably comprises a dealkylation catalyst regenerator, which may be of the type conventionally used in the art, and is preferably a fluidized bed regenerator. According to a further preferred embodiment, in order to prevent the oxygen-containing gas stream from coming into contact with the hydrogen-containing gas stream during the regeneration process, the dealkylation catalyst regenerator is a fluidized bed regenerator having a seal hopper to further improve the safety level of the system. In other preferred embodiments, transfer of catalyst between the dealkylation catalyst regenerator and the dealkylation unit fluidized bed reactor can be accomplished using a conventional regenerated catalyst riser and a spent catalyst riser.

According to a further preferred embodiment, the fluidized bed regenerator may further comprise a reactor receiver, a regenerator receiver, a regenerator feed tank, and optionally a reducing agent.

According to a fourth aspect of the present invention, there is provided a catalytic cracking system comprising a catalytic cracking unit and a catalytic cracking product treatment system according to the present application, wherein the catalytic cracking unit comprises a catalytic cracking reactor and optionally a catalytic cracking catalyst regenerator, wherein the gas oil outlet of the catalytic cracking reactor is in communication with the catalytic cracking product inlet of the catalytic cracking product treatment system.

In a preferred embodiment, the light gasoline outlet of the catalytic cracking product treatment system is in communication with the feed inlet of the catalytic cracking reactor so as to return the light gasoline to the catalytic cracking reactor for processing and increase the yield of light olefins.

In a preferred embodiment, the aromatic refined petroleum outlet of the catalytic cracking product treatment system is in communication with the feed inlet of the catalytic cracking reactor so as to return the aromatic refined petroleum product to the catalytic cracking reactor for processing and increasing the yield of light olefins.

In a particularly preferred embodiment, the light gasoline outlet and the aromatic refined product outlet are, respectively, in communication with the feed inlet of the catalytic cracking reactor.

According to the present application, the catalytic cracking reactor may be of a type that is traditionally used in technology. According to a preferred embodiment, the catalytic cracking reactor comprises a dense phase fluidized bed reactor and an upflow reactor arranged from top to bottom.

According to a particularly preferred embodiment of the present invention, as illustrated in FIG. 1, the catalytic cracking method is carried out as follows: the original petroleum product 6 is introduced into the catalytic cracking unit 1 for the catalytic cracking reaction, the resulting gas oil 7 is sent to the first separation unit 2 for separation to obtain light gasoline 8, heavy gasoline 9 and optionally one or more other products; light gasoline 8 is returned to the catalytic cracking unit 1 for subsequent reaction, heavy gasoline 9 is sent to the second separation unit 3 (for example, to a distillate separation column) to separate and obtain a medium-density gasoline fraction 10 and a heavy gasoline fraction 11, with an average gasoline fraction of 10 sent to the extraction separation unit 4 of aromatic compounds for separation to obtain an aromatic refined petroleum product 13, benzene 14, toluene 15 and xylene 16, and the aromatic refined petroleum product 13 is returned to the catalytic cracking unit 1 for subsequent reaction, the heavy gasoline fraction 11 is sent to the dealkylation unit 5 for the hydrodealkylation reaction, the hydrodealkylated liquid product 12 and heavy gasoline 9 are mixed and then returned to the second separation unit 3 for further separation.

As illustrated in FIG. 2, according to the following preferred embodiment, in catalytic cracking unit 1, feedstock 6 is introduced into upflow reactor 19 through feed nozzle 17, the resulting mixture of gas oil and catalyst flows up along the riser into dense phase fluidized bed reactor 20, a light mixture gasoline 8 and aromatic refined petroleum product 13 enters the dense phase fluidized bed reactor 20 through a light gasoline nozzle 18 to react, the resulting mixture of gas oil and catalyst is separated in a gas-solid separator 21 to produce gas oil 7, and the spent catalyst is catalyzed cracking is sent to the catalytic cracking catalyst regenerator 22 for regeneration, and then returned to the bottom of the riser reactor 19 for return after degassing in the degassing tank 23.

According to a further preferred embodiment, as illustrated in FIG. 3, in the dealkylation unit 5, the heavy gasoline fraction 11 and hydrogen 24 are sent to the fluidized hydrodealkylation reactor 26 and contacted with a dealkylation catalyst to carry out the hydrodealkylation reaction, the reaction product is sent to the gas-liquid separation tank 27 to separate the gas and liquid to obtain a hydrodealkylation liquid product. 12 and hydrogen, the spent dealkylation catalyst is removed from the fluidized hydrodealkylation reactor 26, passed into the seal hopper 29 through the reactor receiver 28, then into the regenerator feed tank 25 and finally into the dealkylation catalyst regenerator 30 (fluidized bed regenerator) for regeneration by decoking. in an oxygen-containing atmosphere in the regenerator, and the resulting regenerated dealkylation catalyst is released into the regenerator receiver 31 and then passed through the barrier hopper 29 into the reducing agent 32, where it is reduced and returned to the fluidized hydrodealkylation reactor 26 for reuse.

According to some preferred embodiments of the present invention, the following technical solutions are provided.

Point 1: method of processing catalytic cracking gasoline, comprising the following stages:

performing a first fractionation of catalytically cracked gasoline and/or catalytically cracked gas oil from the catalytic cracking unit to produce light gasoline, heavy gasoline, and optionally other products;

carrying out a second fractionation of heavy gasoline to obtain a medium-density gasoline fraction and a heavy gasoline fraction, wherein the medium-density gasoline fraction contains C6-C8 light aromatic compounds, and the heavy gasoline fraction contains C9+ heavy aromatic compounds;

carrying out the extraction of aromatic compounds from the medium-density gasoline fraction to obtain aromatic compounds VTX (benzene, toluene, xylene) and aromatic refined petroleum product;

sending the heavy gasoline fraction into a fluidized bed reactor and contacting it with a second catalyst for a dealkylation reaction in the presence of hydrogen to produce a dealkylated liquid product and a spent catalyst; And

sending the dealkylated liquid product to a second fractionation after mixing with heavy gasoline.

Point 2: the method according to point 1, which additionally includes the step of returning light gasoline to the catalytic cracking unit for the subsequent catalytic cracking reaction.

Point 3: the method according to point 1 or 2, in which light gasoline has an initial boiling point of 20-40°C and a final boiling point of 80-100°C; Heavy gasoline has an initial boiling point of 80-100°C and a final boiling point of 200-250°C.

Point 4: the method according to point 1, in which the medium density gasoline fraction has an initial boiling point of 80-100°C and a final boiling point of 120-150°C; and the heavy gasoline fraction has an initial boiling point of 120-150°C and a final boiling point of 200-250°C.

Item 5: the method according to item 1, which additionally includes the step of returning the aromatic refined petroleum product to the catalytic cracking unit for the subsequent catalytic cracking reaction.

Point 6: the method according to point 1, in which the dealkylation reaction is carried out under the following conditions: temperature is 250-700°C, pressure is 0-6 MPa, the average hourly mass-volume feed rate of the starting material is 0.1-6.5 h ^{- 1} , and the molar ratio of hydrogen and hydrocarbons is 1-14; preferably, the dealkylation reaction is carried out under the following conditions: temperature is 320-580°C, pressure is 0.1-4.5 MPa, hourly average mass-volume feed rate of the starting material is 0.5-6 h ^-1 , and the molar ratio of hydrogen and hydrocarbons is 2-11; Preferably, the dealkylation reaction is carried out under the following conditions: the temperature is 350-550°C, the pressure is 1-3.5 MPa, the hourly average mass-volume feed rate of the starting material is 1.5-4 h ^-1, and the molar ratio of hydrogen and hydrocarbons is 3-6.

Claim 7: the method of claim 1, wherein the second catalyst comprises a support and an active metal component supported on the support; the active metal component is present in an amount ranging from 0.01 to 50 wt. % relative to the total weight of the second catalyst.

Point 8: method according to point 7, in which the carrier contains, relative to the total weight of the carrier: 1-60 wt. % zeolite, 5-99 wt. % inorganic oxide, and 0-70 wt. % clay; the zeolite comprises a mesoporous zeolite, a macroporous zeolite, or a suitable combination; the inorganic oxide is at least one material selected from silica, alumina, zirconia, titanium dioxide and amorphous silica alumina; the clay is at least one material selected from kaolin, montmorillonite, diatomite, attapulgite, sepiolite, halloysite, hydrotalcite, bentonite and rectorite.

Item 9: the method according to item 8, in which the mesoporous zeolite is a ZSM zeolite and/or a ZRP zeolite, and the macroporous zeolite is one or more materials selected as β zeolite, REY zeolite, REHY zeolite, super-resistant zeolite Y and having high silica content zeolite Y.

Claim 10: The method of claim 7, wherein the active metal component is one of rare earth metals and transition metals or a combination of two or more of these metals.

Claim 11: The method of claim 1, wherein the method further comprises: introducing a second spent catalyst into a fluidized bed regenerator for regeneration and returning the resulting second regenerated catalyst to the fluidized bed reactor.

Claim 12: The method of claim 11, wherein the fluidized bed regenerator includes a gate hopper, and the regeneration method includes: passing a second spent catalyst into the fluidized bed regenerator for regeneration through the gate hopper, and returning the second regenerated catalyst to the fluidized bed reactor through the gate hopper. bunker

Claim 13: The method of claim 1, wherein the fluidized bed reactor is a dense phase moving bed reactor, a dense phase fluidized bed reactor, a combination reactor that is composed of a dense phase moving bed reactor and a dense phase fluidized bed reactor, a combination reactor that is composed of two or more dense-phase moving bed reactors, or a combination reactor consisting of two or more dense-phase fluidized bed reactors.

Item 14: The method according to item 1 or 13, wherein the fluidized bed reactor is an upflow reactor or a downflow reactor.

Item 15: a catalytic cracking method, which includes the steps of contacting a feedstock petroleum product with a first catalyst in a catalytic cracking reactor to react a catalytic cracking to produce catalytic cracking gas oil and treating the catalytic cracking gas oil using the catalytic cracking gas oil treatment method of any one of items 1- 14.

Item 16: a catalytic cracking gasoline processing system comprising a catalytic cracking gasoline inlet, a first separation unit, a second separation unit, an aromatic extraction unit, and a dealkylation unit; wherein

the first separation unit includes a first separator, and the first separator includes a first gas oil inlet, a light gasoline outlet, a heavy gasoline outlet, and optionally one or more other product outlets; the first gas oil inlet is in communication with the catalytic cracking gasoline inlet; the light gasoline outlet is not necessarily in communication with the feed inlet of the catalytic cracking reactor;

the second separation unit includes a distillate separation column, the distillate separation column comprising a second gas oil inlet, a medium density gasoline fraction outlet, and a heavy gasoline fraction outlet, and the second gas oil inlet is in communication with the heavy gasoline outlet;

the aromatic compound extraction unit contains an aromatic compound extraction and separation device, and the aromatic compound extraction and separation device contains a third gas oil inlet, a BTX aromatic compound outlet, and an aromatic refined petroleum product outlet; the third gas oil inlet is in communication with the outlet of the medium-density gasoline fraction; the aromatic refined petroleum product outlet is not necessarily in communication with the catalytic cracking reactor feed inlet;

The dealkylation unit comprises a fluidized bed reactor, the fluidized bed reactor contains a fourth gas oil inlet and a gas oil outlet, the fourth gas oil inlet is in communication with the heavy fraction gasoline outlet of the distillate separation column, and the gas oil outlet is in communication with the second gas oil inlet of the distillate separation column.

Claim 17: The system of claim 16, wherein the aromatic extraction and separation apparatus comprises an aromatic extractor, an aromatic separation column and a solvent regenerator, and the aromatic extractor comprises a third gas oil inlet, a solvent inlet, an aromatic and solvent mixture outlet, and production of aromatic refined petroleum products; the solvent regenerator includes an aromatic-solvent mixture inlet, an aromatic compound outlet, and a solvent outlet, and the aromatic-solvent mixture inlet is in communication with the aromatic-solvent mixture outlet of the aromatic extractor; the aromatics separation column contains a fifth gas oil inlet and a BTX aromatics outlet, the fifth gas oil inlet is in communication with the aromatics outlet of the solvent regenerator, and the BTX aromatics outlet contains a benzene outlet, a toluene outlet, and a xylene outlet.

Item 18: The system of item 16, wherein the dealkylation unit further comprises a second catalyst regenerator, which is a fluidized bed regenerator equipped with a seal hopper.

Claim 19: The system of claim 16, in which the fluidized bed reactor is a dense phase moving bed reactor, a dense phase fluidized bed reactor, a combination reactor that is composed of a dense phase moving bed reactor and a dense phase fluidized bed reactor, a combination reactor that is composed of two or more dense-phase moving-bed reactors, or a combination reactor that consists of two or more dense-phase fluidized-bed reactors; The dense phase moving bed reactor is an upflow reactor; the dense phase fluidized bed reactor is a bubble fluidized bed reactor, a turbulent fluidized bed reactor or the like; and the fluidized bed reactor is an upflow reactor or a downflow reactor.

Clause 20: a catalytic cracking system comprising a catalytic cracking unit and the system of any one of clauses 16-19, wherein the gas oil outlet of the catalytic cracking unit is in communication with the catalytic cracking gas oil inlet of the system, the feed inlet of the catalytic cracking unit is in communication with the light outlet gasoline, and the catalytic cracker feed inlet is in communication with the aromatic refined petroleum outlet.

Examples

The present application will be further illustrated by the presentation of the following examples, but the present application is not limited to them.

Example of catalyst production 1

Aluminum oxide sol (Qilu Branch of Sinopec Catalyst Co. Ltd.) was divided into two parts of equal weight, one part was mixed with kaolin (Qilu Branch of Sinopec Catalyst Co. Ltd.), and turned into a suspension with a solid content of 40 wt. % using deionized water, mixed evenly, the pH value of the suspension was adjusted to 3.5 using hydrochloric acid, this pH value was maintained, kept and aged at a temperature of 60 ° C for 1.5 hours, the rest of the alumina sol was added, stirred for 1.0 hour to form a colloid, ZSM-5 molecular sieve (supplied from Qilu affiliate of Sinopec Catalyst Co. Ltd.) and Y molecular sieve (supplied from Qilu affiliate of Sinopec Catalyst Co. Ltd.) were added to form a suspension carrier (with a solids content of 35 wt.%), further mixed and subjected to spray drying to obtain a microsphere carrier, and the weight ratio of molecular sieve ZSM-5: molecular sieve Y: kaolin: alumina sol was 30:10:39:21 .

The microspherical support was then calcined at 500°C for 1 hour, washed with ammonium sulfate solution (the ratio of ammonium sulfate: microspherical support: water was 0.5:1:10) at a temperature of 60°C until the sodium oxide content was less than 0 .25 wt. %, washed with deionized water and filtered, and then dried at a temperature of 110°C to obtain carrier C1 used in this example.

Carrier C1 was subjected to hydrothermal aging at a temperature of 800°C in an atmosphere of 100% steam for 12 hours, and then added to a PdCl ₂ solution for impregnation by moisture capacity at an impregnation temperature of 80°C for 120 minutes, dried for 2 hours at a temperature of 150 °C, and then the carrier impregnated with palladium was added to the chloroplatinic acid solution for impregnation by moisture capacity at an impregnation temperature of 80°C for 120 minutes; the resulting product was washed with deionized water, dried for 2 hours at a temperature of 150°C, calcined for 4 hours at a temperature of 500°C, and the calcined catalyst was reduced for 2 hours at a temperature of 100°C in an atmosphere of hydrogen containing gas to obtain catalyst H1 containing active metals Pd and Pt, while the introduced amounts of Pd and Pt were 0.04 wt., respectively. % and 0.04 wt. % (based on metal elements and relative to the total mass of the catalyst), the abrasion index was 3.2%/h, and the particles were distributed in size as follows: mass fraction of particles having sizes from 0 to 20 μm, was 3%, the mass fraction of particles having sizes from 0 to 40 μm was 22%, the mass fraction of particles having sizes from 0 to 149 μm was 89%, and the average particle size was 75 μm.

Example of manufacturing catalyst 2

Carrier C1 was subjected to hydrothermal aging at a temperature of 800°C in an atmosphere of 100% steam for 12 hours, and was added to the NiCl ₂ solution for impregnation by moisture capacity at an impregnation temperature of 80°C for 120 minutes, washed with deionized water, dried for 2 hours at a temperature of 150°C, calcined for 4 hours at a temperature of 500°C, and the calcined catalyst was subjected to preliminary sulfurization treatment to obtain NiS-containing catalyst H2, while the incorporated amount of NiS was 6.5% (in terms of Ni basis and relative to to the total mass of the catalyst), the abrasion index was 3.2%/h, and the particles were distributed in size as follows: the mass fraction of particles having sizes from 0 to 20 μm was 3%, the mass fraction of particles having sizes from 0 up to 40 µm was 22%, the mass fraction of particles having sizes from 0 to 149 µm was 89%, and the average particle size was 75 µm.

Example of manufacturing catalyst 3

The aluminum oxide sol was divided into two parts of equal mass, one part was mixed with kaolin, and turned into a suspension with a solid content of 40 wt. % using deionized water, mixed evenly, the pH value of the suspension was adjusted to 3.5 using hydrochloric acid, this pH value was maintained, kept and aged at a temperature of 60 ° C for 1.5 hours, the rest of the alumina sol was added, stirred for 1.0 hour to form a colloid, Y molecular sieve was added to form a carrier slurry (35 wt.% solids), further mixed and spray dried to form a microsphere carrier, wherein the weight ratio was molecular sieve Y: kaolin : aluminum oxide sol was 40:39:21.

The microspherical support was then calcined at 500°C for 1 hour, washed with ammonium sulfate solution (the ratio of ammonium sulfate: microspherical support: water was 0.5:1:10) at a temperature of 60°C until the sodium oxide content was less than 0 .25 wt. %, washed with deionized water and filtered, and then dried at a temperature of 110°C to obtain carrier C2 used in this example.

The C2 carrier was subjected to hydrothermal aging at a temperature of 800°C in an atmosphere of 100% steam for 12 hours, and then added to the PdCl ₂ solution for impregnation by moisture capacity at an impregnation temperature of 80°C for 120 minutes, dried at a temperature of 150°C for 2 hours, the carrier impregnated with palladium was then added to the chloroplatinic acid solution for impregnation by moisture capacity at an impregnation temperature of 80°C for 120 minutes, washed with deionized water, dried at a temperature of 150°C for 2 hours, calcined at a temperature of 500°C for 4 hours, the calcined catalyst was reduced for 2 hours at a temperature of 100°C in an atmosphere of hydrogen-containing gas to obtain catalyst H1 containing the active metals Pd and Pt, while the incorporated amounts of Pd and Pt were 0.04 wt., respectively. % and 0.04 wt. % (based on metal elements and relative to the total mass of the catalyst), the abrasion index was 2.8%/h, and the particles were distributed in size as follows: mass fraction of particles having sizes from 0 to 20 μm, was 2.5%, the mass fraction of particles having sizes from 0 to 40 μm was 19%, the mass fraction of particles having sizes from 0 to 149 μm was 91%, and the average particle size was 73 μm.

Example of manufacturing catalyst 4

Carrier C1 was subjected to hydrothermal aging at a temperature of 800°C in an atmosphere of 100% steam for 12 hours, and then added to the NiCl ₂ solution for impregnation by moisture capacity at an impregnation temperature of 80°C for 120 minutes, washed with deionized water, dried at a temperature of 150 °C for 2 hours, calcined at a temperature of 500 °C for 4 hours, and the calcined catalyst was reduced in an atmosphere of hydrogen-containing gas at a temperature of 100 °C for 2 hours without preliminary sulfurization treatment to obtain Ni-containing catalyst H4, while the embedded amount Ni was 6.5% (on a Ni basis and based on total catalyst weight), the abrasion index was 3.2%/h, and the particle size distribution was as follows: mass fraction of particles ranging in size from 0 to 20 μm was 3%, the mass fraction of particles having sizes from 0 to 40 μm was 22%, the mass fraction of particles having sizes from 0 to 149 μm was 89%, and the average particle size was 75 μm.

Example of catalyst production 5

Carrier C1 was added, without hydrothermal aging, to the PdCl ₂ solution for impregnation according to moisture capacity at an impregnation temperature of 80°C for 120 minutes, dried at a temperature of 150°C for 2 hours, then the carrier impregnated with palladium was added to the solution of chloroplatinic acid for impregnation by moisture capacity at an impregnation temperature of 80°C for 120 minutes, washed with deionized water, dried at a temperature of 150°C for 2 hours, calcined at a temperature of 500°C for 4 hours, the calcined catalyst was restored in an atmosphere of hydrogen-containing gas at a temperature 100°C for 2 hours to obtain catalyst H5 containing the active metals Pd and Pt, while the incorporated amounts of Pd and Pt were 0.04 wt., respectively. % and 0.04 wt. % (based on metal elements and relative to the total mass of the catalyst), the abrasion index was 3.2%/h, and the particles were distributed in size as follows: mass fraction of particles having sizes from 0 to 20 μm, was 2.5%, the mass fraction of particles having sizes from 0 to 40 μm was 16%, the mass fraction of particles having sizes from 0 to 149 μm was 87%, and the average particle size was 78 μm.

The properties of the feedstocks used in the following examples and comparative examples are shown in Tables 1 and 2, wherein feedstock A was a vacuum distillate and feedstock B was catalytic cracked gasoline.

In the following examples and comparative examples, the catalytic cracking catalyst used in the catalytic cracking reactor was a conventional C3 catalytic cracking catalyst produced under the trade name DMMC-2 by ChangLing affiliate of Sinopec Catalyst Co. Ltd.

Examples 1-5

The experiments were carried out according to the schemes presented in Fig. 1-3, respectively, using starting material A, wherein the dealkylation reaction was carried out using a pilot-scale continuous regeneration dense phase fluidized bed reactor, and the corresponding conditions and products are listed in Table 3.

Example 6

The experiments were carried out according to the schemes presented in Fig. 1 and 3, but without a catalytic cracking unit, the feedstock B was sent directly to the dealkylation unit, and the dealkylation reaction was carried out using a pilot dense phase fluidized bed continuous regeneration reactor, and the corresponding conditions and products are listed in Table 3.

Example 7

The experiment was carried out as described in Example 1, except that catalyst H4 was used. Relevant conditions and products are listed in Table 4.

Example 8

The experiment was carried out as described in Example 1, except that catalyst H5 was used. Relevant conditions and products are listed in Table 4.

Example 9

The experiment was carried out as described in Example 1, except that an H2 catalyst was used and a riser reactor was used as a dealkylation reactor. Relevant conditions and products are listed in Table 4.

Example 10

The experiment was carried out as described in Example 1, except that catalyst H3 was used, a combination reactor containing an upflow reactor and a dense phase fluidized bed reactor was used as a dealkylation reactor. Relevant conditions and products are listed in Table 4.

Comparative example 1

The experiment was carried out as described in Example 1, except that the heavy gasoline was directly sent to the aromatic extraction and separation unit without performing distillate separation and hydrodealkylation reaction and separated to obtain the aromatic refined petroleum product, benzene, toluene, xylene, and C9+ aromatics , wherein the light gasoline was returned to the catalytic cracking reactor for subsequent reaction, but the aromatic refined petroleum product was not returned to the catalytic cracking reactor. Relevant conditions and products are listed in Table 5.

Comparative example 2

The experiment was carried out as described in Example 1, except that the catalytic cracker product was not subjected to hydrodealkylation, but only fractionation, as well as extraction and separation of aromatics, was carried out to obtain light olefins, BTX, light gasoline, heavy gasoline, aromatic refined petroleum product etc., while light gasoline and aromatic refined petroleum products were not returned to the catalytic cracking reactor. Relevant conditions and products are listed in Table 5.

Comparative example 3

The experiment was carried out as described in Example 1, except that the reactor of the dealkylation unit was a fixed bed reactor and continuous catalyst regeneration was not carried out. Relevant conditions and products are listed in Table 5.

Comparative example 4

The experiment was carried out as described in Example 1, except that support C2 was used as a catalytic cracking catalyst in a dealkylation reactor and the reaction was carried out in the absence of hydrogen. Relevant conditions and products are listed in Table 5.

From the results of the above examples and comparative examples, it is clear that the method of treating the catalytic cracking product according to the present application can reduce the content of C9+ aromatic compounds in the product and increase the content of light aromatic compounds BTX. The catalytic cracking method according to the present application can effectively convert heavy aromatic compounds in cracked products into light aromatic compounds, increase the content of BTX aromatic compounds and reduce the content of C9+ aromatic compounds. The process of the present application employs a fluidized bed reaction system which is flexible in operation and provides long-term operation during which the catalyst can be easily regenerated and mass and heat transfer are uniform.

The present invention has been illustrated in detail hereinabove by presenting preferred embodiments, but is not intended to be limited to the embodiments indicated. Various modifications may be made consistent with the inventive concept of the present application, and said modifications are within the scope of the present application.

It should be noted that the various technical features that are described in the above embodiments may be combined in any suitable manner without conflict, and in order to avoid redundancy, the various possible combinations are not described in this application, but such combinations are also within the scope of this application .

In addition, various embodiments of the present invention may be combined in any way, provided that such combination does not deviate from the spirit of the present application, and such combined embodiments should be considered as the disclosure of the present invention.

Claims (40)

1. A method for processing a catalytic cracking product, comprising the following stages: i) performing a first fractionation of the catalytic cracked gas oil or catalytic cracked gasoline from the catalytic cracking reactor to produce heavy gasoline and optionally light gasoline, wherein the light gasoline has an initial boiling point of 20-40° C. and a final boiling point of 80-100 °C, and heavy gasoline has an initial boiling point of 80-100°C and a final boiling point of 200-250°C; ii) carrying out a second fractionation of the heavy gasoline to obtain a heavy gasoline fraction and optionally a medium density gasoline fraction, wherein the medium density gasoline fraction contains light aromatic compounds C6-C8, has an initial boiling point of 80-100°C and a final boiling point, component 120-150°C, and the heavy gasoline fraction contains C9+ aromatic compounds, has an initial boiling point of 120-150°C, and a final boiling point of 200-250°C; iii) optionally extracting aromatics from the medium gravity gasoline fraction to produce BTX (benzene, toluene, xylene) aromatics and an aromatic refined petroleum product; iv) sending the heavy gasoline fraction into a fluidized bed reactor and contacting it with a dealkylation catalyst for dealkylation in the presence of hydrogen to produce a dealkylated liquid product and a spent dealkylation catalyst; And v) returning said dealkylated liquid product to step (ii) to carry out a second fractionation of said heavy gasoline. 2. The method according to claim 1, in which the light gasoline is returned to the catalytic cracking reactor for subsequent catalytic cracking reaction. 3. The method according to claim 1 or 2, in which the aromatic refined petroleum product is returned to the catalytic cracking reactor for subsequent catalytic cracking reaction. 4. The method according to any of the preceding paragraphs, in which dealkylation is carried out under the following conditions: temperature is 250-700°C, pressure (gauge pressure) is 0-6 MPa, the average hourly mass-volume feed rate of the starting material is 0.1-120 h ^-1 , or the reaction time is 0.1-40 seconds, and the molar ratio of hydrogen and hydrocarbons is 1-14; preferably, dealkylation is carried out under the following conditions: temperature is 320-580°C, pressure is 0.1-4.5 MPa, hourly average mass-volume feed rate of the starting material is 0.5-80 h ^-1 , or reaction duration is 0. 5-30 seconds, and the molar ratio of hydrogen and hydrocarbons is 2-11; preferably, dealkylation is carried out under the following conditions: temperature is 350-550°C, pressure is 1-3.5 MPa, hourly average mass-volume feed rate of the starting material is 1.5-50 h ^-1 , or reaction duration is 1-15 seconds , and the molar ratio of hydrogen and hydrocarbons is 3-6. 5. The method according to any of the preceding claims, wherein the dealkylation catalyst comprises a support and an active metal component supported on the support, wherein the active metal component is present in an amount of 0.01-50 wt.%, relative to the total weight of the dealkylation catalyst , relative to the total weight of the carrier, the carrier contains: 1-80 wt.% zeolite, 5-99 wt.% inorganic oxide, and 0-70 wt.% clay; wherein the zeolite contains a mesoporous zeolite, a macroporous zeolite, or a corresponding combination; the inorganic oxide is one or more materials, selected from silica, alumina, zirconia, titanium dioxide and amorphous silica alumina; the clay is one or more materials, such as kaolin, montmorillonite, diatomite, attapulgite, sepiolite, halloysite, hydrotalcite, bentonite and rectorite, and the active metal component is one or more rare earth metals and transition metals. 6. The method according to claim 5, wherein the mesoporous zeolite is one or more materials, selected as ZSM zeolites and ZRP zeolites, and the macroporous zeolite is one or more materials, selected as β zeolites, REY zeolites, zeolites REHY, ultra-resistant Y zeolites and high silica Y zeolites. 7. The method according to claim 5 or 6, in which, relative to the total weight of the zeolite, the mesoporous zeolite is present in an amount of 50-100 wt.%, preferably 70-90 wt.%; and the macroporous zeolite is present in an amount of 0-50% by weight, preferably 10-30% by weight. 8. The method according to any of the preceding paragraphs, further comprising: sending the spent dealkylation catalyst to a fluidized bed regenerator for regeneration and returning the resulting regenerated dealkylation catalyst to the fluidized bed reactor. 9. The method according to claim 8, in which the fluidized bed regenerator contains a seal hopper, and the following are provided for regeneration: sending the spent dealkylation catalyst to the fluidized bed regenerator for regeneration through the barrier hopper; and returning the resulting regenerated dealkylation catalyst to the fluidized bed reactor through the barrier hopper. 10. The method according to claim 9, wherein the fluidized bed regenerator further comprises a reactor receiver, a regenerator receiver, a regenerator feed tank and optionally a reducing agent, and for carrying out the regeneration the following are provided: removing the spent dealkylation catalyst from the fluidized bed reactor, sending it to the reactor receiver and then to the regenerator feed tank through the seal hopper, and then transferring it to the fluidized bed regenerator from the regenerator feed tank; regenerating the spent dealkylation catalyst in a regenerator by burning coke in an oxygen-containing atmosphere to obtain a regenerated dealkylation catalyst; And removing the regenerated dealkylation catalyst from the fluidized bed regenerator, directly returning the regenerated dealkylation catalyst to the fluidized bed reactor for reuse through the regenerator receiver, or returning the regenerated dealkylation catalyst to the fluidized bed reactor for reuse after passing through a reducing agent for recovery; Preferably, the method additionally includes a pressure reduction step for the spent catalyst in the barrier hopper and a pressure increase step for the regenerated catalyst. 11. The method as claimed in any one of the preceding claims, wherein the fluidized bed reactor is selected from a moving bed reactor, a dense phase fluidized bed reactor, a combination reactor consisting of a moving bed reactor and a dense phase fluidized bed reactor, a combination reactor consisting of two or more moving bed reactors, or a combination reactor that consists of two or more dense phase fluidized bed reactors. 12. Catalytic cracking method, which includes the following stages: a) contacting a hydrocarbon-containing petroleum feedstock with a catalytic cracking catalyst in a catalytic cracking reactor for a catalytic cracking reaction to produce catalytic cracking gas oil; And b) treating catalytic cracking gas oil by the method according to any of the preceding paragraphs. 13. A catalytic cracking product processing system, comprising a catalytic cracking product inlet, a first separation unit, a second separation unit, a dealkylation unit, and an optional aromatic extraction unit; wherein the first separation unit comprises a first separator, the first separator comprising a first gas oil inlet, a light gasoline outlet, a heavy gasoline outlet, and optionally one or more other product outlets, wherein the first gas oil inlet is in communication with the catalytic cracking product inlet, and optionally a light gasoline outlet is in communication with the feed inlet of the catalytic cracking reactor; the second separation unit includes a distillate separation column, the distillate separation column comprising a second gas oil inlet, a medium density gasoline fraction outlet, and a heavy gasoline fraction outlet, and the second gas oil inlet is in communication with the heavy gasoline outlet; the aromatics extraction unit comprises an aromatics extraction and separation device, wherein the aromatics extraction and separation device comprises a third gas oil inlet, a BTX aromatics outlet and an aromatic refined petroleum product outlet, the third gas oil inlet is in communication with the medium density gasoline fraction outlet, and optionally an outlet the aromatic refined petroleum product is in communication with the feed inlet of the catalytic cracking reactor; The dealkylation unit comprises a fluidized bed reactor, the fluidized bed reactor contains a fourth gas oil inlet and a gas oil outlet, the fourth gas oil inlet is in communication with the heavy fraction gasoline outlet of the distillate separation column, and the gas oil outlet is in communication with the second gas oil inlet of the distillate separation column. 14. The system of claim 13, wherein the aromatic extraction and separation apparatus comprises an aromatic extractor, an aromatic separation column and a solvent regenerator, wherein the aromatic extractor comprises a third gas oil inlet, a solvent inlet, an aromatic and solvent mixture outlet, and production of aromatic refined petroleum products; the solvent regenerator includes an aromatic-solvent mixture inlet, an aromatic compound outlet, and a solvent outlet, and the aromatic-solvent mixture inlet is in communication with the aromatic-solvent mixture outlet of the aromatic extractor; the aromatics separation column contains a fifth gas oil inlet and a BTX aromatics outlet, the fifth gas oil inlet is in communication with the aromatics outlet of the solvent regenerator, and the BTX aromatics outlet contains a benzene outlet, a toluene outlet and a xylene outlet. 15. The system of claim 13 or 14, wherein the dealkylation unit further comprises a dealkylation catalyst regenerator which is a fluidized bed regenerator equipped with a seal hopper. 16. The system of claim 15, wherein the dealkylation catalyst regenerator further comprises a reactor receiver, a regenerator receiver, a regenerator feed reservoir, and an optional reducing agent. 17. The system according to any one of paragraphs. 13-16, in which the fluidized bed reactor is selected as a moving bed reactor, a dense phase fluidized bed reactor, a combination reactor which is composed of a moving bed reactor and a dense phase fluidized bed reactor, a combination reactor which is composed of two or more reactors with moving bed, or combination reactor, which consists of two or more dense-phase fluidized bed reactors; preferably the moving bed reactor is an upflow reactor; and the dense phase fluidized bed reactor is a bubble fluidized bed reactor, a turbulent fluidized bed reactor, etc. 18. A catalytic cracking system comprising a catalytic cracking unit and a catalytic cracking product processing system according to any one of claims. 13-17, wherein the catalytic cracking unit comprises a catalytic cracking reactor and an optional catalytic cracking catalyst regenerator, the gas oil outlet of the catalytic cracking reactor is in communication with the catalytic cracking product inlet of the catalytic cracking product treatment system, the feed inlet of the catalytic cracking reactor is in communication with the outlet light gasoline, and/or the feed inlet of the catalytic cracking reactor is in communication with the outlet of the aromatic refined petroleum product.