CN112592249B - Method and device for preparing ethylene by catalytic conversion of crude oil - Google Patents

Abstract

The invention relates to a method for preparing ethylene by catalytic conversion of crude oil, belonging to the technical field of catalytic conversion of crude oil. Heating the crude oil by a heating furnace or a heat exchanger, then feeding the heated crude oil into a crude oil separation tower or a flash tower, separating the crude oil into a crude oil light component and a crude oil heavy component with a higher boiling point according to a boiling point, and performing graded catalytic conversion on the heavy component after further heating under conditions suitable for different components; the heavy component and the light component of the crude oil are respectively subjected to graded catalytic conversion in two reactors, so that the direct preparation of ethylene and propylene from the crude oil with the combination of catalytic cracking and cracking is realized.

Description

Method and device for preparing ethylene by catalytic conversion of crude oil

Technical Field

The invention belongs to the technical field of crude oil catalytic conversion, and particularly relates to a method for preparing ethylene by catalytic conversion of crude oil.

Background

The low-carbon olefin represented by ethylene and propylene is the most basic raw material in chemical industry, and the existing catalytic conversion technology is used for producing gasoline and diesel oil and simultaneously producing the low-carbon olefin as a byproduct, so that the requirement of the current market on organic chemical raw materials can not be met. Aromatic hydrocarbon is an important organic chemical raw material with second only to ethylene and propylene in yield and scale, derivatives of the aromatic hydrocarbon are widely used for producing chemical products and fine chemicals such as chemical fibers, plastics and rubber, and the demand of the aromatic hydrocarbon in the world is continuously increased along with the continuous development of petrochemical industry and textile industry. Natural gas or light petroleum fractions are mostly used as raw materials at home and abroad, low-carbon olefin is produced by adopting a steam cracking process in an ethylene combined device, and a large amount of other basic raw materials such as olefin, aromatic hydrocarbon and the like are produced as byproducts during the production of ethylene. Although the steam cracking technology is developed for decades and the technology is continuously improved, the steam cracking technology still has the advantages of high energy consumption, high production cost and CO ₂ The discharge amount is large, the product structure is not easy to adjust, and other technical limitations, and the traditional technology for producing ethylene and propylene by steam cracking is facing a severe test. The catalytic conversion method for preparing ethylene and the byproduct of low-carbon olefins such as propylene and butylene and chemical raw materials such as aromatic hydrocarbon are new ways to solve the problem of resource shortage and low-cost production of chemical products, and become important research subjects and hot problems at present.

In the aspect of preparing ethylene by catalytic conversion and by-producing low-carbon olefins such as propylene, butylene and the like, the following ideas are mainly provided:

1. the reaction raw material is divided into different fractions by a distillation tower, and the different fractions are respectively subjected to catalytic reaction in different reactors. For example, CN109575982a provides a method for preparing low carbon olefins and aromatic hydrocarbons by catalytic cracking of crude oil, the crude oil is desalted and dehydrated, then heated in a heating furnace, and then enters a distillation tower to separate the crude oil into light and heavy components, and the cutting point is between 150 ℃ and 300 ℃; the light components coming out of the top of the tower and the heavy components coming out of the bottom of the tower contact and react with the high-temperature catalyst in the atmosphere of water vapor in the two reactors.

2. The materials in the reactor are fed and reacted layer by layer. For example, CN1898362 provides a method for producing light olefins and aromatics, in which a raw material is contacted with a catalytic cracking catalyst, the reaction is divided into at least two layers of feeding materials according to the properties of the raw material, and different liquid reaction products from a fractionating tower except a target product are returned to a reactor from different positions for conversion again. CN1215041A provides a method for preparing ethylene, propylene, aromatic hydrocarbon and the like by directly converting various feed hydrocarbons into olefins, and a reactor is provided with a plurality of groups of feed inlets, so that hydrocarbons with different properties enter a device from different feed inlets, and are subjected to cracking reaction under the same process conditions of all parts. CN104560154A provides a hydrocarbon catalytic conversion method for producing light olefins and light aromatics in high yield, which comprises the following steps: contacting a heavy hydrocarbon raw material with a cracking catalyst in a first reactor to perform catalytic cracking reaction, and then separating to obtain a first carbon deposition catalyst and a first reaction product; injecting light hydrocarbon raw materials from the upstream of the second reactor, and injecting medium hydrocarbon raw materials from the middle part of the second reactor to perform catalytic cracking reaction; and introducing the reaction mixture generated in the second reactor into a third reactor for continuous reaction, and then separating to obtain a second carbon deposition catalyst and a second reaction product. Wherein the cracking catalyst is a cracking catalyst containing modified beta zeolite, and the modified beta zeolite is beta zeolite modified by Lin and transition metal M.

3. Outside the raw oil riser, additionally establishing a reactor to convert different fractions by catalysis again, namely adopting a multi-reactor form, carrying out conventional raw oil reaction in the first reactor, and feeding one or more fractions such as crude gasoline into the additionally established reactor for further conversion to obtain a target product after fractionation; for example, CN1388216 discloses a catalytic conversion method for preparing propylene, butylene and gasoline with low olefin content, comprising the following steps: (1) Injecting preheated hydrocarbon oil (still liquid) into a riser, contacting and reacting with a catalyst containing pentasil zeolite and Y-type zeolite, and introducing an oil agent mixture into a fluidized bed through the riser; (2) Injecting gasoline into the fluidized bed, contacting and reacting with the catalyst from the riser; (3) Separating the oil mixture, stripping the reacted catalyst, regenerating in a regenerator, and returning the regenerated catalyst to the riser for reuse. The method can not only increase the yield of low-carbon olefin, but also produce high-quality gasoline with low olefin content. CN1258580C discloses a method and a system for modifying gasoline by catalytic conversion, which is characterized in that a catalytic modification reactor is additionally arranged in a reaction-regeneration system of a heavy oil catalytic conversion device to carry out catalytic modification reaction on gasoline fraction by catalytic conversion. The upgraded catalytically converted gasoline fraction may be a naphtha whole fraction, a naphtha light fraction or a naphtha heavy fraction obtained by establishing a secondary condensation system at the top of the fractionator.

4. The light raw material is used for producing low-carbon olefin. CN104557378A discloses a method for producing propylene by naphtha catalytic cracking. The method comprises the following steps: (1) Under the pretreatment condition, contacting naphtha with a pretreatment agent to obtain treated oil with reduced alkaline nitrogen content; (2) And (2) under the condition of naphtha catalytic cracking reaction, contacting the treated oil and water obtained in the step (1) with a catalyst to obtain a catalytic cracking product.

5. In order to increase the yield of the light olefins, a 'cocatalyst' suitable for cracking the small-molecular hydrocarbons can be added, and the propylene can be increased by 1-1.5% by adding 5-8% of the heavy oil reaction catalyst.

The ethylene preparation from the crude oil requires higher reaction temperature, generally higher than 650 ℃; crude oil has wider components, and the reaction process is a process of gradually cracking and gradually reducing molecular weight; small molecules are difficult to activate, the higher the required reaction temperature is, the higher the temperature is, the thermal cracking reaction is carried out naturally, and the selectivity of a target product is influenced; how to allocate the reaction temperature and the molecular characteristics of the crude oil, balance the catalytic cracking reaction and the thermal cracking reaction, and have important significance for realizing the limit control of the reaction; the expected reaction process is that the specific gravity of catalytic reaction is increased as much as possible in the macromolecular cracking stage of heavy oil and the like, thermal cracking is limited, the temperature is gradually increased and the thermal cracking reaction proportion is increased in the next molecular cracking stage; however, in the prior art, heat is provided in the inlet area of the reactor in the reaction process, the reaction is a gradual cooling process, particularly for the reaction for preparing ethylene, the reaction temperature is higher in the initial stage, namely the heavy oil cracking stage at the lower part of the reactor, and heavy components are directly subjected to thermal cracking reaction, so that the effect of catalytic cracking reaction is reduced.

Disclosure of Invention

The invention aims to provide a method for preparing ethylene by catalytic conversion of crude oil, which separates desalted and dehydrated crude oil into light and heavy components, the light and heavy components separately enter a catalytic conversion ethylene preparation device, and ethylene and propylene are prepared by fluidized catalytic conversion under respective required conditions; the method can realize the high-yield preparation of various low-carbon olefin products, has low equipment investment and low energy consumption, can be used for processing heavy petroleum raw materials or crude oil to produce chemical products, and also provides a device for realizing the method.

The technical scheme of the invention is as follows:

a method for preparing ethylene by catalytic conversion of crude oil comprises preheating/heating desalted and dehydrated crude oil in a heating furnace or a heat exchanger, separating the crude oil into crude oil light component (light component with low boiling point) and crude oil heavy component (heavy component with high boiling point) according to boiling point in a crude oil separation tower or a flash tower, and catalytically cracking the crude oil heavy component and the crude oil light component in a catalytic conversion ethylene preparation device to prepare ethylene; the catalytic conversion ethylene preparation device is provided with a reaction system and a catalyst regeneration system; the reaction system is provided with one or two reactors, at least one reactor, namely a first reactor, is arranged in an upper-lower two-stage series connection subarea reaction mode, the lower part is a reaction zone which takes large-molecule catalytic cracking as a main part under mild conditions, and the upper part is a reaction zone which carries out small-molecule catalytic cracking and thermal cracking to prepare ethylene and propylene under continuous temperature rise and high-rigor conditions; the two reaction zones are independently controlled; the hierarchical control of reaction time, reaction temperature and catalyst is realized through hierarchical reaction, and larger molecules pass through longer reaction time, shorter molecules, short reaction time and high-severity conditions; the catalyst regeneration system is provided with a regenerator, the first reactor is provided with an upper catalyst inlet and a lower catalyst inlet from the regenerator, the catalyst from the regenerator enters the first reactor twice, the catalyst from the regenerator enters the first reactor in an upper and lower way, the catalyst at the upper part is used as a boundary, the first reactor forms an upper reaction zone and a lower reaction zone (a double-zone mode) which are independently controlled, the heat provided for the first reactor can be controlled by controlling the flow and the temperature of the two catalysts from the regenerator, so that the reaction conditions of the two reaction zones in the first reactor are controlled, the reactions of the upper reaction zone and the lower reaction zone under different conditions are realized, namely the catalytic cracking conversion under the mild condition of a component with a larger molecular weight is realized, the cracking reaction under the severe condition of a small molecule is also realized, and the independent control is realized, the optimization of the catalytic cracking or cracking reaction and the thermal cracking or the cracking reaction is realized, the improvement and the control on the selectivity of a target product are realized, the conversion efficiency and the utilization rate of hydrogen are improved, the byproducts such as methane is reduced, and the yield of ethylene and propylene prepared by catalytic conversion of crude oil is improved; one of the heavy component and the light component of the crude oil is reacted in a reactor which is connected in series at the upper stage and the lower stage, namely a first reactor, and the other component is also reacted in the first reactor or in an independent second reactor; the specific process is as follows:

(1) Pressurizing and preheating the desalted and dehydrated crude oil, and then feeding the crude oil into a crude oil separation tower or a flash tower to separate the crude oil into a crude oil light component and a crude oil heavy component;

(2) When heavy components of crude oil react in a first reactor which is connected in series at an upper stage and a lower stage, the heavy components react under mild conditions in a lower reaction zone of catalytic cracking reaction under mild conditions, the lower reaction zone mainly carries out catalytic cracking conversion of heavy oil macromolecules into main reaction, the advantages of catalytic cracking are exerted, intermediate components with C12-C3 as main components are generated, then cracking reaction is carried out under high-severity conditions in the upper reaction zone, the combined optimization of catalytic conversion and thermal conversion is realized, ethylene and propylene are generated, meanwhile, methane is reduced, and the proportion of propylene in products is improved; specifically, crude oil heavy components enter a lower reaction zone of a first reactor, and are subjected to catalytic cracking reaction under the environment of a catalyst I (also called a lower regenerant) introduced from a regenerator through a first regeneration vertical pipe, so that the first-stage reaction of the heavy components is realized; then the reaction product and the catalyst I together enter an upper reaction zone for further temperature rise, the catalyst III (also called as an upper regenerant) introduced from a regenerator through a third regeneration vertical pipe enters the first reactor again to participate in the reaction of the upper reaction zone, heat is supplied to the upper reaction zone, and catalytic cracking and thermal cracking reaction under harsh conditions are carried out in the upper reaction zone, so that the further reaction of the heavy component first-stage catalytic cracking reaction product is realized; the reaction temperature of the lower reaction zone is 490-600 ℃, the reaction time is 0.5-5.0 s, the reaction temperature of the upper reaction zone is 550-720 ℃, and the reaction pressure gauge pressure is 0.10-0.30 Mpa; when heavy components of crude oil react in a first reactor, the light components of the crude oil directly enter the upper reaction zone for cracking reaction, or react in an independent second reactor, a catalyst II is introduced from a regenerator through a second regeneration vertical pipe, the reaction temperature of the second reactor is 640-720 ℃, and the reaction time is 0.5-4.0 seconds;

or the heavy component of the crude oil reacts in the second reactor, the light component of the crude oil reacts in the first reactor, the light component of the crude oil directly reacts in the upper reaction zone or reacts in the lower reaction zone first, and then enters the upper reaction zone to react; specifically, the heavy components of the crude oil directly enter a second reactor and react in the environment of a catalyst II introduced from a regenerator through a second regeneration vertical pipe, wherein the reaction temperature is 550-700 ℃; the light crude oil components react in the first reactor, the light crude oil components directly enter the upper reaction zone for cracking reaction, or the light crude oil components enter the lower reaction zone firstly, catalytic cracking reaction is carried out mainly under the environment of a catalyst I from a regenerator, then reaction products and the catalyst I upwards enter the upper reaction zone together for continuous catalytic cracking and thermal cracking reaction, and the catalyst III enters the first reactor again and supplies heat to the upper reaction zone; when the light crude oil components enter the lower reaction zone for reaction, the reaction temperature of the lower reaction zone is 560-620 ℃, the reaction time is 0.5-5.0 s, the reaction temperature of the upper reaction zone is 560-720 ℃, and the reaction pressure gauge pressure is 0.13-0.40 Mpa.

(3) And the material flow after the reaction of the second reactor and the first reactor enters a settler for gas-solid separation to obtain a reaction product, and the separated catalyst is subjected to steam stripping in a steam stripping section and then enters a regenerator for regeneration and recycling.

The method for preparing ethylene by catalytic conversion of crude oil further comprises the step of recombining crude oil into a mixture containing a diesel oil component, a wax oil component and a heavy oil component in the crude oil, wherein the boiling point of the mixture is higher than 145 ℃; the light component of the crude oil is non-condensable gas, naphtha or light naphtha component in the crude oil, or the non-condensable gas, naphtha or light naphtha component and light diesel oil component in the crude oil, and the boiling point is lower than 360 ℃.

The method for preparing ethylene by catalytic conversion of crude oil further comprises the step of heating the heavy component and/or the light component of the crude oil, and then allowing the heated heavy component and/or the light component of the crude oil to enter a reactor to participate in reaction, wherein the heating temperature of the light component of the crude oil is 160-600 ℃; the heating temperature of heavy components of crude oil is 200-370 ℃.

The method for preparing ethylene by catalytic conversion of crude oil further comprises the steps of adding one or mixture of steam, external C4 and/or naphtha components into the light components of the crude oil, mixing to form light components introduced into the reactor, heating, and then introducing the light components into the reactor to participate in reaction; the addition of the steam R23 accounts for 0-50% of the light components introduced into the reactor.

In the above method for preparing ethylene by catalytic conversion of crude oil, further, after the reaction product gas component is separated from the reaction product in the fractionating tower, the obtained reaction product liquid component is subjected to hydrotreating or cracking, so as to increase the hydrogen content or open a ring of a partial ring structure, especially a monocyclic component, to form a reaction product liquid component hydrogenation component;

in a liquid product formed by product fractionation, the liquid component hydrogenation component of the reaction product is a fraction hydrotreating product with the distillation range of more than or equal to 280 ℃ separated from the reaction product, or a fraction/component hydrotreating product with naphtha and diesel oil components separated from the reaction product;

the reaction product liquid component hydrogenation component returns to the catalytic conversion ethylene preparation device to participate in the reaction, and the reaction product liquid component hydrogenation component reacts with the crude oil heavy component in the same reactor or reacts with the crude oil light component in the same reactor;

when the light components of the crude oil react in the second reactor, the liquid component hydrogenation component of the reaction product enters the second reactor at the downstream of the light components of the crude oil or the light components introduced into the reactor, and the catalytic cracking reaction is mainly carried out by utilizing the catalyst and heat after the reaction of the light components of the crude oil or the light components introduced into the reactor; when the reaction product liquid component hydrogenation component reacts with the crude oil light component or the light component introduced into the reactor in the first reactor, the crude oil light component or the light component introduced into the reactor reacts in the upper reaction zone, the reaction product liquid component hydrogenation component firstly carries out catalytic cracking reaction mainly in the lower reaction zone under mild conditions, and then carries out cracking reaction together with the crude oil light component or the light component introduced into the reactor under high-severity conditions in the upper reaction zone to produce ethylene and propylene.

In the method for preparing ethylene by catalytic conversion of crude oil, one or more of the heavy components of the crude oil, the light components of the crude oil and the light components introduced into the reactor exchange heat with the reaction product flowing out of the settler, the heated reaction product enters the reactor, and the quenching and cooling of the reaction product are realized.

The method for preparing the ethylene by the catalytic conversion of the crude oil further supplements fuel in a regenerator. When the regeneration of ethylene and propylene coke produced by crude oil is not enough to provide the heat required by the reaction, the heat is supplemented to the reaction regeneration system by supplementing fuel in a regenerator.

In the method for preparing ethylene by catalytic conversion of crude oil, further, heavy oil or recycled oil or fuel oil is supplemented at any 1-3 of the three positions of the outlet of the first reactor, the outlet of the second reactor and the stripping section, the coke formation amount is increased, the quenching and cooling of reaction products are realized, the coke formation enters a regenerator through a spent agent, the coke-burning load and the heat supply capacity of the regenerator are improved, and the cooling of the reaction products is realized; the heavy oil, heavy recycle oil and fuel oil are from the bottoms of a fractionator or other means of treating the reaction products.

In specific implementation, further, heavy oil or heavy cycle oil or fuel oil can be firstly used as washing cycle oil to enter a product fractionating tower, so that washing of a reaction product, namely product gas carrying a catalyst and liquefaction of heavy components are realized, the heavy cycle oil containing the catalyst returns to an outlet of a reactor or/and a stripping section from the bottom of the product fractionating tower to increase coke formation, or returns to a regenerator for afterburning, and the heat balance of the reaction is realized.

According to the method for preparing ethylene by catalytic conversion of crude oil, heavy components of the crude oil are firstly subjected to hydrogenation treatment, heavy metal, sulfur and alkaline nitrogen elements are removed, the hydrogen content is improved, and the property is improved, so that the obtained hydrogenated components H of the heavy components of the crude oil enter a catalytic conversion ethylene preparation device for catalytic conversion to prepare ethylene. Separation of light and heavy components from crude oil and hydroprocessing of heavy components is well known to those skilled in the engineering companies, and can be practiced by those skilled in the engineering companies by hydrogenating the liquid product in a product separation column.

The invention also provides a device for preparing ethylene by catalytic conversion of crude oil, wherein a reaction system and a catalyst regeneration system are arranged at the downstream of a heating furnace or a heat exchanger (a crude oil heating part) and a crude oil separation tower or a flash tower (a light and heavy component separation part); the reaction system is provided with a first reactor and a second reactor; the catalyst regeneration system is provided with a regenerator, a settler and a stripping section;

the first reactor is arranged in an upper-lower two-stage series partition mode, is a reactor with upper-lower two-stage series connection and two-stage catalyst circulation, and comprises a lower reaction zone at the lower part and an upper reaction zone at the upper part, wherein the lower reaction zone is used for low-temperature catalytic cracking reaction, and the upper reaction zone is used for high-temperature ethylene preparation cracking reaction; a first regenerant inlet at the lower part of the lower reaction zone is communicated with a first regenerant outlet of the regenerator through a first regeneration vertical pipe, and a third regenerant inlet at the lower part of the upper reaction zone is communicated with a third regenerant outlet of the regenerator through a third regeneration vertical pipe; a second regenerant inlet at the lower part of the second reactor is communicated with a second regenerant outlet of the regenerator through a second regeneration vertical pipe;

a heavy component inlet is arranged at the lower part of the first reactor, and a light component inlet is arranged at the lower part of the second reactor; or a heavy component inlet is arranged at the lower part of the second reactor, and a light component inlet is arranged at the lower part of the first reactor; or a heavy component inlet is arranged at the lower part of the second reactor, and a light component inlet is arranged at the lower part of the upper reaction zone of the first reactor; a material flow pipeline is arranged between the heavy component inlet and the bottom of the crude oil separation tower or the flash tower so as to introduce the heavy component of the crude oil separated by the crude oil separation tower or the flash tower, and a material flow pipeline is arranged between the light component inlet and the top of the crude oil separation tower or the flash tower so as to introduce the light component of the crude oil separated by the crude oil separation tower or the flash tower;

the first reactor and the second reactor are selected from a riser, a fluidized bed single or composite reactor.

In the invention, the catalyst active component is selected from HY, USY, REY, REHY, REUSY, H-ZSM-5, Y-type zeolite, L zeolite, ZSM-5 zeolite, beta zeolite, aluminum phosphate zeolite, mordenite, or one or a mixture of modified zeolites.

The reaction system and the catalyst regeneration system are known to be provided with a reactor, a settler, a steam stripping section and a regenerator, wherein the outlet of the reactor is communicated with a gas-solid separation device in the settler, the steam stripping section is arranged below the settler, the lower part of the steam stripping section is communicated with the regenerator through a spent riser (spent catalyst conveying pipe), and the regenerator is communicated with a regenerant inlet of the reactor through a regenerated riser (regenerated catalyst conveying pipe); in the specific implementation and arrangement: the reactor and the regenerator are preferably arranged in parallel, and the reactor and the settler can be coaxially arranged or arranged in parallel; the top of the settler is provided with a product outlet of the reaction system; one or more reactors can be arranged in one set of reaction regeneration system to meet the requirements of different raw materials, and the outlets of the reactors can be communicated with the same settler to carry out gas-solid separation operation on the reacted material flow; the lower part of the reactor is provided with a raw material feeding port (a feeding nozzle when liquid phase feeding is carried out), the feeding port is arranged above or below a regenerant inlet of the reactor, and a lifting or fluidizing medium gas inlet is arranged at the bottom of the reactor. The conventional specific arrangement and connection positions of the reactor, the settler, the stripping section and the regenerator in the reaction regeneration system, and the inlet and outlet positions and specification requirements of various material flows can be grasped by engineering technicians, and are not described in detail below. As is known, the reaction process of the reactor using a reaction regeneration system in the form of a riser is as follows: the regenerated catalyst or called regenerating agent enters the lower part of the reactor through the regeneration vertical pipe, goes upward along the reactor, the reaction raw material enters the reactor through the feed inlet, contacts with the catalyst and flows upward together to realize reaction, the material flow after the reaction enters the settler to separate the catalyst, the product flows out through the product outlet, the catalyst enters the stripping section for stripping, and the spent catalyst or called spent agent enters the regenerator through the spent vertical pipe to realize regeneration and recycle.

The invention provides a method for preparing ethylene and propylene by combining catalysis and thermal conversion of crude oil grading, reaction gradual heating grading reaction based on a catalytic cracking mechanism. As is well known to those skilled in the art, the heavy oil catalytic cracking process can be regarded as a parallel sequential reaction, heavy oil macromolecules (not less than C18) are firstly cracked to generate medium molecule (C5-C12) products such as gasoline, diesel oil and the like, the catalytic cracking reaction can be highlighted by a lower cracking temperature, and the catalytic cracking reaction is facilitated at 490-530 ℃; part of gasoline and diesel oil is cracked into C3-C8 at 530-600 deg.c; at higher temperature, 600-750 ℃, C3-C8 will be further cracked into C1, C2, C3 small molecular products. The invention follows the reaction rule and arranges the temperature gradient series connection: the low temperature zone, the sub-high temperature zone and the high temperature zone strive to exert the maximum effectiveness of the catalyst. The invention reduces the yield of low-value target products such as coke and methane on the premise of lower energy consumption; the yield of high-value target products such as ethylene and propylene is improved.

The method adopts schemes with different conditions to process each component of the crude oil, optimizes the reaction condition, exerts the characteristics of catalytic reaction and thermal reaction, forms a combined scheme, increases the reaction and product selectivity and improves the efficiency.

Description of the drawings:

FIG. 1 is a schematic process diagram according to one embodiment of the present invention;

FIG. 2 is a schematic process diagram according to a second embodiment of the present invention;

FIG. 3 is a schematic diagram of a third process according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a fourth process of the present invention;

FIG. 5 is a schematic diagram of a fifth process according to an embodiment of the present invention;

the numbering marks in the figure are as follows:

r10 is a first reactor or an upper-lower two-stage series reactor; r11 first catalyst pre-lift gas; the system comprises an R11A first catalyst pre-lifting gas inlet, an R12 crude oil heavy component (a heavy component separated from crude oil), an R12H crude oil heavy component hydrogenation component (namely a heavy component in the hydrotreated crude oil), an R13 crude oil heavy component atomized steam, an R14 reaction product, an R14A first regenerant inlet, an R14G reaction product gas component, an R14L reaction product liquid component, an R14H reaction product liquid component hydrogenation component (namely a reaction product liquid component after hydrotreating), an R15A second regenerant inlet, an R16 external C4 and/or naphtha component, an R17 lower reaction zone and an R18 upper reaction zone, wherein the first catalyst pre-lifting gas inlet is connected with the R11A first catalyst pre-lifting gas inlet; r20 second reactor, R21 second catalyst pre-lift gas; r22 light components introduced into the reactor, R22A light components inlet, R23 steam; an R24A third regenerant inlet, an R50 crude oil heavy component hydrogenation reactor and an R60 hydrogenation reactor;

s10, a stripping section, S11, a stripping component; s12, a spent agent slide valve and an S12A spent agent vertical pipe;

a D10 settler, a D11 settling cyclone separator and a D14 settler reaction product outlet;

a G10 regenerator, G11 catalyst regeneration gas, a G11A regeneration gas inlet, a G12A spent inlet, a G14 first regeneration standpipe (first regenerated catalyst delivery pipe), a G14A first regeneration agent outlet, a G14V first regeneration slide valve; g15 second regeneration standpipe (second regeneration catalyst transfer line), G15A second regenerant outlet, G15V second regeneration slide valve; g16, a G17 cyclone separator, a G17 burnt flue gas and a G17A flue gas outlet; g18 fuel, G19 regenerator dilute phase zone, G24 third regeneration standpipe (third regeneration catalyst transfer line), G24A third regenerant outlet, G24V third regeneration slide valve;

a0 heating furnace or heat exchanger, A1 reaction product heat exchanger, A2 second reaction product heat exchanger; f0 crude oil, light components (light components separated from the crude oil) of the F0G crude oil, an F3 heat exchange cold medium, a medium after F4 heat exchange, F20 washing cycle oil, and F22 heavy cycle oil or oil slurry; f21 liquefied gas and dry gas products, F23 light cycle oil components; a T00 crude oil separation tower or flash tower, a T10 fractionating tower; TIC temperature display control; h2 hydrogen.

The specific implementation mode is as follows:

the technical solutions of the present invention are described below with specific examples, but the scope of the present invention is not limited thereto.

The specific implementation process is as follows:

pressurizing the desalted and dehydrated crude oil F0 to 0.8-1.6 MPa by using a pump, feeding the crude oil F0 into a crude oil heating furnace or a heat exchanger A0 for heating, and separating the crude oil F0 into a light component and a heavy component according to boiling points in a crude oil separation tower or a flash tower T00 (or a fractionating tower or a flash tower), wherein the light component with low boiling point, namely the light component F0G of the crude oil, flows out from the top of the crude oil separation tower or the flash tower T00, and the heavy component R12 of the crude oil with high boiling point flows out from the bottom of the crude oil separation tower or the flash tower T00; in specific implementation, the operation of separation according to boiling point is realized by controlling the operating pressure and temperature of the crude oil separation tower or the flash tower T00, and the skilled person can master that the actual boiling point ranges of the light components and the heavy components of the crude oil can also be adjusted by adjusting the heat exchange of the crude oil separation tower or the flash tower T00 and the outlet temperature of a crude oil heating furnace or a heat exchanger A0, for example, the dry point or the end point of the light components F0G of the crude oil with low boiling point is controlled to be changed between 145 ℃ and 220 ℃; the high boiling crude oil heavies R12 comprises a wax oil component, a heavy oil or residue component; the light component F0G of the crude oil and the heavy component R12 of the crude oil return to a heating furnace or a heat exchanger A0 for heating, the light component F0G of the crude oil is heated to about 350-560 ℃, the heavy component R12 of the crude oil is heated to about 250-360 ℃, and the heated light component F0G of the crude oil enters a catalytic cracking ethylene production device for producing ethylene and propylene by fluidized catalysis, or the heavy component R12 of the crude oil is subjected to hydrotreating to form a heavy component hydrogenated component R12H of the crude oil and enters a catalytic cracking ethylene production device for producing ethylene and propylene by fluidized catalysis;

atomizing a crude oil heavy component R12 or a crude oil heavy component hydrogenation component R12H by using crude oil heavy component atomizing steam R13, then sending the atomized crude oil heavy component or crude oil heavy component hydrogenation component into a lower reaction zone R17 of a first reactor R10, feeding a catalyst I from a regenerator G10 into the first reactor R10 at the bottom, and carrying out catalytic conversion on the heavy component in the environment of the catalyst I at the reaction temperature of about 490-560 ℃ for 1.0-3.0 seconds to realize the conversion of the heavy component into liquefied gas and gasoline; then the gas and the catalyst enter an upper reaction zone R18 upwards together, the catalyst III from the regenerator G10 enters the reaction zone, heat is further provided for the first reactor, the temperature is increased, and the cracking reaction under high-severity conditions is carried out to obtain ethylene, wherein the reaction temperature of the upper reaction zone R18 is about 670 ℃, and the reaction time is controlled within 2.0 seconds;

when the heavy component R12 of the crude oil reacts with the first reactor which is connected in series in an upper-lower grading way, the light component F0G of the crude oil enters an upper reaction zone R18 to directly carry out cracking reaction; or the light component F0G of the crude oil enters a second reactor R20 for cracking reaction for 0.5 to 2.0 seconds; in specific implementation, in order to obtain higher ethylene and propylene products, the liquid product with the carbon number of more than 5 in the reaction product can be recycled in the first reactor R10 together with the heavy component R12 of the crude oil after hydrogenation.

The first implementation mode comprises the following steps:

in the method for preparing ethylene by catalytic conversion of crude oil according to the embodiment, the device shown in fig. 1 is adopted, and a reaction system and a catalyst regeneration system are arranged at the downstream of a crude oil heating furnace or a heat exchanger A0 and a crude oil separation tower or a flash tower T00; the reaction system comprises a first reactor R10 and a second reactor R20, and in specific implementation, the first reactor R10 and the second reactor R20 are selected from a riser and a single or composite reactor of a fluidized bed, and the reactors in the embodiment are both risers; the catalyst regeneration system is provided with a regenerator G10, a settler D10 and a stripping section S10; the method comprises the following steps of (1) preheating desalted and dehydrated crude oil F0 serving as a raw material in a crude oil heating furnace or a heat exchanger A0, and separating the crude oil F0 into two components according to boiling points by using a crude oil separation tower or a flash tower T00, namely a crude oil heavy component R12 and a crude oil light component F0G, wherein the crude oil heavy component R12 and the crude oil light component F0G both enter a catalytic conversion ethylene production device for catalytic cracking to produce ethylene; in specific implementation, the heavy component R12 of the crude oil is a mixture containing a diesel component, a wax oil component and a heavy oil component in the crude oil, the boiling point is higher than 200 ℃, and the light component F0G of the crude oil is a non-condensable gas, naphtha or light naphtha component in the crude oil, and the boiling point is lower than 200 ℃;

the regenerator G10 and the settler D10 are arranged in parallel, the second reactor R20 and the settler D10 are coaxially arranged, the outlet of the first reactor R10 is communicated with a settling cyclone D11 in the settler D10, the outlet of the second reactor R20 is also communicated with a cyclone in the settler D10, the stripping section S10 is arranged below the settler D10, and a stripping component S11 is arranged in the stripping section S10; the lower part of the stripping section S10 is communicated with a regenerator G10 through a spent agent stand pipe S12A from a spent agent inlet G12A, and a spent agent slide valve S12 is arranged on the spent agent stand pipe S12A;

the first reactor R10 is arranged in an upper-lower two-stage series partition mode and comprises a lower reaction zone R17 at the lower part and an upper reaction zone R18 at the upper part, the lower reaction zone R17 carries out low-temperature catalytic cracking reaction, and the upper reaction zone R18 carries out high-temperature ethylene preparation cracking reaction; a first regenerant inlet R14A at the lower part of the lower reaction zone R17 is communicated with a first regenerant outlet G14A of the regenerator G10 through a first regeneration vertical pipe G14, a first regeneration slide valve G14V is arranged on the first regeneration vertical pipe G14, a third regenerant inlet R24A at the lower part of the upper reaction zone R18 is communicated with a third regenerant outlet G24A of the regenerator G10 through a third regeneration vertical pipe G24, and a third regeneration slide valve G24V is arranged on the third regeneration vertical pipe G24; a first catalyst pre-lift gas inlet R11A is provided at the bottom of the first reactor R10 to introduce a first catalyst pre-lift gas R11;

a second regenerant inlet R15A at the lower part of the second reactor R20 is communicated with a second regenerant outlet G15A of the regenerator G10 through a second regeneration vertical pipe G15, and a second regeneration slide valve G15V is arranged on the second regeneration vertical pipe G15; introducing a second catalyst pre-lift gas R21 at the bottom of the second reactor R20;

a heavy component inlet is arranged at the lower part of the first reactor R10, a heavy component reaction raw material and crude oil heavy component atomized steam R13 can be introduced from the heavy component inlet, and a light component inlet R22A is arranged at the lower part of the second reactor R20; a material flow pipeline is arranged between the heavy component inlet and the bottom of the crude oil separation tower or the flash tower T00 so as to introduce the crude oil heavy component R12 separated by the crude oil separation tower or the flash tower T00, and a material flow pipeline is arranged between the light component inlet R22A and the top of the crude oil separation tower or the flash tower T00 so as to introduce the crude oil light component F0G separated by the crude oil separation tower or the flash tower T00;

in specific implementation, as shown in figure 1, adding steam R23 and an external C4 and/or naphtha component R16 into the separated light component F0G of the crude oil, and mixing to form a light component R22 introduced into the reactor, wherein the adding amount of the steam R23 accounts for 5-50% of the light component R22 introduced into the reactor; the light component R22 introduced into the reactor is heated to 160-600 ℃ by a crude oil heating furnace or a heat exchanger A0 and then introduced into a second reactor R20; the separated heavy component R12 of the crude oil is heated to 200-370 ℃ by a crude oil heating furnace or a heat exchanger A0 and is introduced into a first reactor R10;

in specific implementation, the regenerator G10 adopts a regeneration form of a quick fluidized bed and a dense-phase fluidized bed of a coke burning tank, and catalysts introduced into a reaction system are all led out from a regeneration zone of the dense-phase fluidized bed at the upper part; a cyclone separator G16 is arranged in a regenerator dilute phase zone G19 of the regenerator G10, the burnt flue gas G17 is discharged from a flue gas outlet G17A at the top of the regenerator G10, the catalyst regeneration gas G11 is introduced from a regeneration gas inlet G11A at the bottom of the regenerator G10, and fuel G28 is supplemented in a dense-phase fluidized bed regeneration zone at the upper part to realize heat supplement of the regenerator, wherein during the specific operation, the temperature and the carbon content of the catalyst in the regenerator are controlled according to the amount of the catalyst introduced into the regenerator, the amount of the burnt air G21 and the amount of the supplemented fuel G28; the top of the settler D10 is provided with a settler reaction product outlet D14 to lead out a reaction product R14;

in the method for preparing ethylene by catalytic conversion of crude oil according to the embodiment, the desalted and dehydrated crude oil is preheated in a heating furnace or a heat exchanger A0 and then enters a crude oil separation tower or a flash tower T00 to be separated into a crude oil light component F0G and a crude oil heavy component R12 according to boiling points, the crude oil heavy component R12 is catalytically converted in a first reactor R10, the crude oil light component F0G is catalytically converted in a second reactor R20, the two reactors adopt the same catalyst, and the active component of the catalyst is selected from HY, USY, REY, REHY, REUSY, H-ZSM-5, Y-type zeolite, L-zeolite, ZSM-5 zeolite, beta zeolite, aluminum phosphate zeolite, mordenite or one or a mixture of the modified zeolites; the specific process flow is as follows:

(1) Pressurizing and preheating the desalted and dehydrated crude oil F0, and then feeding the crude oil F0 into a crude oil separation tower or a flash tower T00 to separate the crude oil F0G and the crude oil R12;

(2) After being heated, a heavy component R12 of crude oil firstly enters a lower reaction zone R17 of a first reactor R10, catalytic cracking reaction is carried out in the environment of a catalyst I introduced from a regenerator G10 through a first regeneration vertical pipe G14, then a reaction product and the catalyst I upwards enter an upper reaction zone R18 for further temperature rise, a catalyst III introduced from the regenerator G10 through a third regeneration vertical pipe G24 enters the first reactor R10 again, participates in the reaction of the upper reaction zone R18, and supplies heat to the upper reaction zone R18; the reaction temperature of the lower reaction zone R17 is 490-600 ℃, the reaction time is 0.5-5.0 s, the reaction temperature of the upper reaction zone R18 is 560-720 ℃, and the reaction pressure gauge pressure is 0.10-0.40 Mpa;

adding steam and external C4 into the crude oil light component F0G, mixing to form a light component R22 introduced into the reactor, reacting in a second reactor R20, introducing a catalyst II from a regenerator G10 through a second regeneration vertical pipe G15, and reacting at the temperature of 650-720 ℃ in the second reactor R20;

(3) And the material flow obtained after the reaction of the second reactor R20 and the first reactor R10 enters a settler D10 for gas-solid separation to obtain a reaction product R14, and the separated catalyst is subjected to steam stripping in a steam stripping section S10 and then enters a regenerator G10 for regeneration and recycling.

Example 1

Adopting the device shown in FIG. 1, and preparing ethylene by catalytic conversion of crude oil;

crude oil F0 Properties: density 0.85, hydrogen content 13.0, K value 12.5, ni content less than 3.0ppm, V content 0.3ppm; the temperature of crude oil F0 is 135 ℃; fractionating crude oil according to boiling point into crude oil light component and crude oil heavy component with boiling point lower than 200 ℃;

first reactor reaction conditions:

heating heavy components of crude oil to 355 ℃, and carrying out steam atomization;

the reaction temperature of the lower reaction zone is 520 ℃, and the reaction time is 1.6 seconds; the reaction temperature of the upper reaction zone is 670 ℃, and the reaction time is 1.0 second; the atomized steam accounts for 10% of the heavy components of the crude oil; the total steam amount of the first reactor is 35 percent of the heavy components of the crude oil;

reaction conditions of the second reactor:

injecting steam and recycling C4 into light components of the crude oil, wherein the steam accounts for 50% of the light components, and the recycling C4 accounts for 7% of the crude oil; heating the light components to 550 ℃;

the reaction time is 1.5 seconds, and the reaction temperature is 700 ℃;

a regenerator: the dense-phase fluidized bed zone is supplemented with fuel oil G18, and the fuel oil quantity is controlled according to the regeneration temperature of 760 ℃.

The reaction settler pressure was 120kpa (gauge pressure); the oil slurry enters a stripping section to increase the green coke, and accounts for 4 percent of the crude oil.

Example 1 product distribution

The second embodiment:

in the method for preparing ethylene by catalytic conversion of crude oil according to the embodiment, the device shown in fig. 2 is adopted, and a reaction system and a catalyst regeneration system are arranged at the downstream of a crude oil heating furnace or a heat exchanger A0 and a crude oil separation tower or a flash tower T00; the reaction system comprises a first reactor R10 and a second reactor R20, and the catalyst regeneration system is provided with a regenerator G10, a settler D10 and a stripping section S10; the method comprises the following steps of (1) preheating desalted and dehydrated crude oil F0 serving as a raw material in a crude oil heating furnace or a heat exchanger A0, and separating the crude oil F0 into two components according to boiling points by using a crude oil separation tower or a flash tower T00, namely a crude oil heavy component R12 and a crude oil light component F0G, wherein the crude oil heavy component R12 and the crude oil light component F0G both enter a catalytic conversion ethylene production device for catalytic cracking to produce ethylene;

a heavy component inlet is arranged at the lower part of the second reactor R20, and a light component inlet R22A is arranged at the lower part of the first reactor R10; adding steam R23 and an external C4 and/or naphtha component R16 into the separated crude oil light component F0G, mixing to form a light component R22 introduced into the reactor, heating the light component R22 introduced into the reactor by a reaction product heat exchanger A1 through a reaction product R14, and introducing into a first reactor R10; the light component R22 introduced into the reactor firstly enters a lower reaction zone R17, and is subjected to catalytic cracking reaction mainly under the environment of a catalyst I from a regenerator G10, the reaction temperature is 560-620 ℃, the reaction time is 0.5-5.0 s, then a reaction product and the catalyst I upwards enter an upper reaction zone R18 for reaction, the catalyst III enters the first reactor R10 again, heat is supplied to the upper reaction zone R18, the reaction temperature of the upper reaction zone R18 is 560-720 ℃, and the reaction pressure gauge pressure is 0.10-0.40 Mpa;

the separated heavy component R12 of the crude oil is heated by a reaction product R14 through a second reaction product heat exchanger A2 and then is introduced into a second reactor R20, and the reaction temperature is 560-700 ℃;

the reaction product R14 led out from the reaction product outlet D14 of the settler enters a fractionating tower T10 after being sequentially subjected to heat exchange and temperature reduction by a light component R22 and a crude oil heavy component R12 which are respectively led into the reactor in a reaction product heat exchanger A1 and a second reaction product heat exchanger A2, and the reaction product R14 is separated into a liquefied gas and dry gas product F21, a light cycle oil component F23 and heavy cycle oil or oil slurry F22; washing circulating oil F20 enters a fractionating tower T10 to realize washing of a reaction product R14 carrying a catalyst and liquefaction of heavy components, and heavy circulating oil F22 containing the catalyst returns to the downstream of an upper reaction zone R18 of a first reactor R10 from the bottom of the fractionating tower T10 to increase coke formation, so that the heat balance of the reaction is realized;

the other parts of the device structure are the same as the first embodiment.

Example 2

The apparatus shown in FIG. 2 was used to produce ethylene starting from crude oil, with the following implementation parameters:

first reactor reaction conditions:

crude oil light components, injecting steam and naphtha, wherein the naphtha is 5 percent of the crude oil;

the reaction temperature of the lower reaction zone is 600 ℃, and the reaction time is 1.2 seconds; the reaction temperature of the upper reaction zone is 680 ℃, and the reaction time is 0.6 second; returning the oil slurry part at the bottom of the fractionating tower T10 to the outlet of the first reactor to increase coking, wherein the oil slurry accounts for 3 percent of the crude oil;

reaction conditions of the second reactor:

crude oil heavy components are reacted at 660 ℃ for 1.8 seconds;

the rest is the same as in example 1.

The third embodiment is as follows:

in the method for preparing ethylene by catalytic conversion of crude oil according to the embodiment, the device shown in fig. 3 is adopted, and a reaction system and a catalyst regeneration system are arranged at the downstream of a crude oil heating furnace or a heat exchanger A0 and a crude oil separation tower or a flash tower T00; the reaction system comprises a first reactor R10 and a second reactor R20, crude oil F0 is used as a raw material, the desalted and dehydrated crude oil F0 is preheated in a crude oil heating furnace or a heat exchanger A0, and then is separated into a crude oil heavy component R12 and a crude oil light component F0G by a crude oil separation tower or a flash tower T00, and the crude oil heavy component R12 and the crude oil light component F0G both enter a catalytic conversion ethylene preparation device for catalytic cracking to prepare ethylene;

the reaction product R14 led out from the reaction product outlet D14 of the settler firstly enters a reaction product heat exchanger A1, exchanges heat with a heat exchange cold medium F3, enters a fractionating tower T10, separates out a reaction product gas component R14G, and then obtains a reaction product liquid component or a heavy oil liquid component R14L with the boiling point of more than 350 ℃ and carries out hydrotreating in a hydrogenation reactor R60, and the obtained reaction product liquid component hydrogenation component R14H returns to the downstream of a second reactor R20 and is converted into gasoline and diesel oil under the mild condition of the downstream of the second reactor, and meanwhile, the short-time reaction of the light component of the crude oil is realized;

the other parts of the device structure are the same as the first embodiment.

The fourth embodiment:

a reaction system and a catalyst regeneration system are arranged at the downstream of a crude oil heating furnace or a heat exchanger A0 and a crude oil separation tower or a flash tower T00; the reaction system comprises a first reactor R10 and a second reactor R20, crude oil F0 is used as a raw material, the desalted and dehydrated crude oil F0 is preheated in a crude oil heating furnace or a heat exchanger A0, and then is separated into a crude oil heavy component R12 and a crude oil light component F0G by a crude oil separation tower or a flash tower T00, and the crude oil heavy component R12 and the crude oil light component F0G both enter a catalytic conversion ethylene preparation device for catalytic cracking to prepare ethylene;

a light component inlet R22A is arranged in an upper reaction zone R18 of the first reactor R10, and the light component R22 introduced into the reactor directly enters the upper reaction zone R18 for preparing ethylene through catalytic cracking;

the reaction product R14 led out from the reaction product outlet D14 of the settler firstly enters a reaction product heat exchanger A1, enters a fractionating tower T10 after exchanging heat with a heat exchange cold medium F3, a reaction product gas component R14G is separated, the residual reaction product liquid component or gasoline component and/or diesel oil component or LCO (LCO) in the liquid component is subjected to hydrotreating in a hydrogenation reactor R60 to form a reaction product liquid component hydrogenation component R14H, the reaction product liquid component hydrogenation component R14H returns to a lower reaction zone R17 at the lower end of the first reactor R10 to carry out a reaction mainly based on catalytic cracking, and the reaction material flow upwards enters an upper reaction zone R18 to be mixed with a light component R22 and a catalyst III led into the reactor, so that the high-temperature cracking reaction is realized.

The other parts of the device structure is the same as the second embodiment.

The fifth embodiment:

in the method for preparing ethylene by catalytic conversion of crude oil according to the embodiment, the device shown in fig. 5 is adopted, and a reaction system and a catalyst regeneration system are arranged at the downstream of a crude oil heating furnace or a heat exchanger A0 and a crude oil separation tower or a flash tower T00; the reaction system comprises a first reactor R10 and a second reactor R20; the catalyst regeneration system is provided with a regenerator G10, a settler D10 and a stripping section S10; the method comprises the following steps of (1) taking crude oil F0 as a raw material, separating the desalted and dehydrated crude oil F0 into a crude oil heavy component R12 and a crude oil light component F0G, and enabling the crude oil heavy component R12 and the crude oil light component F0G to enter a catalytic conversion ethylene preparation device for catalytic cracking to prepare ethylene;

a material flow pipeline is arranged between a heavy component inlet at the lower part of the first reactor R10 and the crude oil separation tower or the flash tower T00, the material flow pipeline is communicated with a crude oil heating furnace or a heat exchanger A0 and a crude oil heavy component hydrogenation reactor R50, a crude oil heavy component R12 enters the crude oil heavy component hydrogenation reactor R50 after being heated by the crude oil heating furnace or the heat exchanger A0, and a crude oil heavy component hydrogenation component R12H obtained by hydrogenation reaction enters the first reactor R10 to participate in the reaction;

the other parts of the device structure are the same as the first embodiment.

Claims (10)

1. A method for preparing ethylene by catalytic conversion of crude oil is characterized in that the crude oil after desalting and dewatering is preheated and enters a crude oil separation tower or a flash tower (T00) to be separated into a crude oil light component (F0G) and a crude oil heavy component (R12) according to boiling points, and the crude oil heavy component (R12) and the crude oil light component (F0G) are subjected to catalytic cracking in a catalytic conversion ethylene preparation device to prepare ethylene; the catalytic conversion ethylene preparation device is provided with a reaction system and a catalyst regeneration system; the reaction system is provided with one or two reactors, at least one reactor, namely a first reactor (R10), is arranged in an upper and lower two-stage series connection zone reaction mode, the catalyst regeneration system is provided with a regenerator (G10), the catalyst from the regenerator (G10) enters the first reactor (R10) in an upper and lower two-way, and the first reactor (R10) forms an upper and lower two reaction zones, namely a lower reaction zone (R17) and an upper reaction zone (R18) by taking the catalyst entering position at the upper part as a boundary; one of the crude heavy fraction (R12) and the crude light fraction (F0G) is reacted in a first reactor (R10), and the other component is also reacted in the first reactor (R10) or in a separate second reactor (R20); the specific process is as follows:

(1) Pressurizing and preheating the desalted and dehydrated crude oil (F0), and then feeding the crude oil into a crude oil separation tower or a flash tower (T00) to separate the crude oil into a crude oil light component (F0G) and a crude oil heavy component (R12);

(2) The heavy component (R12) of the crude oil firstly enters a lower reaction zone (R17) of a catalytic cracking reaction under the mild condition of a first reactor (R10), the catalytic cracking reaction is carried out under the environment of a catalyst I introduced from the regenerator (G10) through a first regeneration vertical pipe (G14), then a reaction product and the catalyst I upwards enter an upper reaction zone (R18) for further heating, a catalyst III introduced from the regenerator (G10) through a third regeneration vertical pipe (G24) enters the first reactor (R10) again to supply heat to the upper reaction zone (R18), and the catalytic cracking and thermal cracking reaction under the severe condition is carried out in the upper reaction zone (R18); the reaction temperature of the lower reaction zone (R17) is 490-600 ℃, the reaction time is 0.5-5.0 s, the reaction temperature of the upper reaction zone (R18) is 550-720 ℃, and the reaction pressure gauge pressure is 0.10-0.30 Mpa; the crude oil light component (F0G) directly enters the upper reaction zone (R18) for cracking reaction, or reacts in a second reactor (R20), a catalyst II is introduced from a regenerator (G10) through a second regeneration vertical pipe (G15), and the reaction temperature of the second reactor (R20) is 640-720 ℃;

or the heavy component (R12) of the crude oil directly enters a second reactor (R20) and reacts in the environment of a catalyst II introduced from a regenerator (G10) through a second regeneration vertical pipe (G15), and the reaction temperature is 550-700 ℃; the crude oil light component (F0G) is reacted in a first reactor (R10), and the crude oil light component (F0G) enters an upper reaction zone (R18) directly or is subjected to cracking reaction; or the light components (FOG) of the crude oil firstly enter the lower reaction zone (R17) to carry out catalytic cracking reaction mainly under the environment of the catalyst I from the regenerator (G10), then the reaction products and the catalyst I upwards enter the upper reaction zone (R18) to continue catalytic cracking and thermal cracking reaction, and the catalyst III enters the first reactor (R10) again to supply heat to the upper reaction zone (R18); when the crude oil light component (F0G) firstly enters the lower reaction zone (R17) for reaction, the reaction temperature of the lower reaction zone (R17) is 560-620 ℃, the reaction time is 0.5-5.0 s, the reaction temperature of the upper reaction zone (R18) is 560-720 ℃, and the reaction pressure gauge pressure is 0.13-0.40 Mpa;

(3) The material flow after the reaction of the second reactor (R20) and the first reactor (R10) enters a settler (D10) for gas-solid separation to obtain a reaction product (R14), and the separated catalyst enters a regenerator (G10) for regeneration after being stripped in a stripping section (S10) for recycling;

the boiling point of the crude oil light component (F0G) is lower than 360 ℃, or the crude oil light component is non-condensable gas and naphtha component, or the crude oil light component is non-condensable gas and light naphtha component, or the crude oil light component is non-condensable gas, naphtha and light diesel component, or the crude oil light component is non-condensable gas, light naphtha and light diesel component;

the crude oil heavy component (R12) is a mixture of a diesel component, a wax oil component and a heavy oil component in the crude oil, and has a boiling point higher than 145 ℃.

2. The method for preparing ethylene by catalytic conversion of crude oil as claimed in claim 1, wherein the heavy crude oil component (R12) and/or the light crude oil component (F0G) are heated and then enter a reactor to participate in the reaction, and the heating temperature of the light crude oil component (F0G) is 160-600 ℃; the heating temperature of the heavy components (R12) of the crude oil is 200-370 ℃.

3. The method for producing ethylene by catalytic conversion of crude oil according to claim 1, wherein the light fraction (F0G) of crude oil is added to one or a mixture of steam (R23), an exogenous C4 and/or naphtha fraction (R16) and mixed to form the light fraction (R22) introduced into the reactor, and the light fraction (R22) is heated and then introduced into the reactor to participate in the reaction; the amount of steam (R23) added is 0% to 50% of the light fraction (R22) introduced into the reactor.

4. The method for producing ethylene by catalytic conversion of crude oil according to claim 3, wherein the reaction product (R14) is separated into a reaction product gas component (R14G) in the fractionating tower T10, and the obtained reaction product liquid component (R14L) is hydrogenated to form a reaction product liquid component hydrogenated component (R14H);

the reaction product liquid component hydrogenation component (R14H) returns to the catalytic conversion ethylene production device to participate in reaction, and the reaction product liquid component hydrogenation component (R14H) reacts with the crude oil heavy component (R12) in the same reactor or reacts with the crude oil light component (F0G) in the same reactor;

when the crude oil light component (F0G) or the light component (R22) introduced into the reactor is reacted in the second reactor (R20), the reaction product liquid component hydrogenation component (R14H) enters the second reactor (R20) at the downstream of the crude oil light component (F0G) or the light component (R22) introduced into the reactor, and the catalytic cracking reaction is mainly carried out by utilizing the catalyst and heat after the reaction of the crude oil light component (FOG) or the light component (R22) introduced into the reactor; when the reaction product liquid component hydrogenation component (R14H) reacts with the crude oil light component (FOG) or the light component (R22) introduced into the reactor in the first reactor (R10), the crude oil light component (F0G) or the light component (R22) introduced into the reactor reacts in the upper reaction zone (R18), and the reaction product liquid component hydrogenation component (R14H) reacts in the lower reaction zone (R17) first and then reacts in the upper reaction zone (R18) together with the crude oil light component (F0G) or the light component (R22) introduced into the reactor.

5. The method for producing ethylene by catalytic conversion of crude oil according to claim 4, wherein the reaction product liquid component hydrogenation component (R14H) is either a product obtained by hydrotreating a fraction having a boiling range of 280 ℃ or more separated from the reaction product (R14) or a product obtained by hydrotreating a fraction having a naphtha and diesel components separated from the reaction product (R14).

6. The method for producing ethylene by catalytic conversion of crude oil according to claim 3, wherein one or more of the heavy crude oil fraction (R12), the light crude oil fraction (F0G) and the light crude oil fraction (R22) introduced into the reactor are heat-exchanged with the reaction product (R14) flowing out of the settler (D10), heated and then introduced into the reactor, and the reaction product (R14) is quenched and cooled.

7. The process for the catalytic conversion of crude oil to ethylene according to claim 1, characterized in that the regenerator (G10) is supplemented with fuel (G18).

8. The process for the catalytic conversion of crude oil to ethylene according to claim 1, wherein the heavy oil is replenished or the oil or fuel oil is recycled at any 1 to 3 of the three positions of the outlet of the first reactor (R10), the outlet of the second reactor (R20) and the stripping section (S10).

9. The method for preparing ethylene by catalytic conversion of crude oil as claimed in claim 1, wherein the crude oil heavy component (R12) is hydrotreated, and the obtained crude oil heavy component hydrogenated component (R12H) is introduced into the catalytic conversion ethylene preparation device for catalytic conversion.

10. The device for preparing ethylene by catalytic conversion of crude oil is characterized in that:

a reaction system and a catalyst regeneration system are arranged at the downstream of the heating furnace or the heat exchanger (A0) and the crude oil separation tower or the flash tower (T00);

the reaction system is provided with a first reactor (R10) and a second reactor (R20); the catalyst regeneration system is provided with a regenerator (G10), a settler (D10) and a stripping section (S10);

the first reactor (R10) comprises a lower reaction zone (R17) at the lower part and an upper reaction zone (R18) at the upper part, the lower reaction zone (R17) is used for low-temperature catalytic cracking reaction, and the upper reaction zone (R18) is used for high-temperature ethylene preparation cracking reaction; a first regenerant inlet (R14A) at the lower portion of the lower reaction zone (R17) is in communication with a first regenerant outlet (G14A) of the regenerator (G10) through a first regeneration riser (G14), and a third regenerant inlet (R24A) at the lower portion of the upper reaction zone (R18) is in communication with a third regenerant outlet (G24A) of the regenerator (G10) through a third regeneration riser (G24); a second regenerant inlet (R15A) at the lower part of the second reactor (R20) is communicated with a second regenerant outlet (G15A) of the regenerator (G10) through a second regeneration riser (G15);

a heavy component inlet is arranged at the lower part of the first reactor (R10), and a light component inlet (R22A) is arranged at the lower part of the second reactor (R20); or a heavy component inlet is arranged at the lower part of the second reactor (R20), and a light component inlet (R22A) is arranged at the lower part of the first reactor (R10); or a heavy component inlet is arranged at the lower part of the second reactor (R20), and a light component inlet (R22A) is arranged at the lower part of the upper reaction zone (R18) of the first reactor (R10); a material flow pipeline is arranged between the heavy component inlet and the bottom of the crude oil separation tower or the flash tower (T00) to introduce the heavy component (R12) of the crude oil separated by the crude oil separation tower or the flash tower (T00), and a material flow pipeline is arranged between the light component inlet (R22A) and the top of the crude oil separation tower or the flash tower (T00) to introduce the light component (F0G) of the crude oil separated by the crude oil separation tower or the flash tower (T00);

the first reactor (R10) and the second reactor (R20) are selected from the group consisting of a riser, a fluidized bed, a single or a composite reactor.

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