CN111807919A

CN111807919A - Method and device for preparing ethylene and propylene by catalytic conversion of petroleum hydrocarbon

Info

Publication number: CN111807919A
Application number: CN202010658196.9A
Authority: CN
Inventors: 石宝珍; 李荻; 郭江伟
Original assignee: Qingdao Jingrun Petrochemical Design & Research Institute Co ltd
Current assignee: Qingdao Jingrun Petrochemical Design & Research Institute Co ltd
Priority date: 2020-07-09
Filing date: 2020-07-09
Publication date: 2020-10-23
Anticipated expiration: 2040-07-09
Also published as: CN111807919B

Abstract

The invention relates to a method for preparing ethylene and propylene by catalytic conversion of petroleum hydrocarbon, belonging to the technical field of catalytic conversion of petroleum hydrocarbon. The method comprises the steps of setting a reactor (R10) as a lower mild catalytic cracking lower reaction zone (R17) at the lower part and a catalytic cracking upper reaction zone (R18) at the upper part, reacting heavy petroleum hydrocarbon (R12) in a low-temperature catalytic cracking lower reaction zone (R17) and a high-temperature catalytic cracking upper reaction zone (R18) in sequence, enabling a catalyst of a regenerator (G10) to respectively enter the lower catalytic cracking reaction zone (R17) and the upper catalytic cracking reaction zone (R18), and realizing the fractional conversion from macromolecules to ethylene propylene in the reaction process in a fractional control mode. The invention also provides a device for realizing the method.

Description

Method and device for preparing ethylene and propylene by catalytic conversion of petroleum hydrocarbon

Technical Field

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

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. Natural gas or light petroleum distillationThe method is divided into raw materials, and low-carbon olefin is produced by adopting a steam cracking process in an ethylene combined device. 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 CO₂The 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 is used for preparing ethylene, and meanwhile, the by-products of chemical raw materials such as low-carbon olefins such as propylene, butylene and the like are new directions for solving the problems 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 low-carbon olefins such as ethylene, propylene, butylene and the like by catalytic conversion, 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 aromatics by catalytic cracking of crude oil, which comprises desalting and dehydrating crude oil, heating in a heating furnace, and then feeding into a distillation tower to separate the crude oil into light and heavy components with a cutting point of 150-300 ℃; 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 nature of the raw material, and different liquid reaction products from a fractionating tower are returned to a reactor from different positions to be converted again except for the target product. CN1215041A provides a method for preparing ethylene, propylene, aromatic hydrocarbon and the like by directly converting various feeding hydrocarbons, wherein a plurality of groups of feeding holes are arranged on a reactor, so that hydrocarbons with different properties enter a device from different feeding holes, and the cracking reaction is carried out under the same process conditions of all parts. CN104560154A provides a hydrocarbon catalytic conversion method for increasing the yield of light olefins and light aromatics, 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 upgrading gasoline by deeply reducing olefin and increasing octane number by catalytic conversion, wherein a catalytic upgrading reactor is added in a reaction-regeneration system of a heavy oil catalytic conversion device to perform catalytic upgrading 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 above technologies for reducing olefins by Fluidized Catalytic Conversion (FCC) and increasing the production of chemical feedstocks have some common drawbacks as follows:

1. different raw materials require different catalysts, heavy oil cracking requires high macromolecule cracking capability of the catalyst, and generally requires a larger aperture; c4 and C5 cracking need catalysts with low carbon olefin selectivity, and generally need smaller pore diameter; the prior art processes described above all use the same catalyst, i.e., only one catalyst. Although 5-8% of auxiliary agent can be added into the regenerator to further convert the small molecules in order to increase the yield of the low-carbon olefins, when the auxiliary agent is added into the FCC catalyst, the catalyst cracking activity is inevitably reduced due to the dilution effect on the catalyst. The heavy oil cracking conversion rate is reduced by 1 percentage point per 5% of the addition of the promoter, which is an important factor that seriously affects the economy of the FCC technology, and the improvement of the objective product is limited due to the low concentration of the promoter after mixing with the heavy oil cracking catalyst.

2. Because the second reaction system needs more reaction heat and generally has less coke formation, the heat generated by the regeneration of the coke formation can not provide the heat required by the reaction, and if the independent second reaction system is established by utilizing the prior art, the heat balance problem is restricted.

3. In all the recycling methods, the fraction is separated by a fractionating tower, cooled into liquid by heat exchange and then returned to the reactor, different fractions are firstly cooled into liquid by the heat exchange of the fractionating tower, and the liquid is returned to the original reactor or is further converted by another reactor directly after separation or after proper re-preheating (still liquid). Through the processes of cooling and heating, the investment of equipment and energy consumption is increased, and the economical efficiency of the process technology is greatly reduced.

4. The preparation of olefin from petroleum hydrocarbon requires higher reaction temperature, generally higher than 650 ℃; the reaction process of catalytically preparing olefin from catalytically cracked material oil, especially heavy material oil, 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 naturally carried out, and the selectivity of target products is influenced; how to allocate the reaction temperature and the molecular characteristics of petroleum hydrocarbon well, balance the catalytic cracking reaction and the thermal cracking reaction well, 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 and propylene by catalytic conversion of petroleum hydrocarbon, which can realize high-yield preparation of various low-carbon olefin products such as ethylene, propylene and the like, has low equipment investment and low energy consumption, and can be used for treating heavy petroleum hydrocarbon or simultaneously treating heavy petroleum hydrocarbon and light hydrocarbon raw materials to produce olefin products. The invention also provides a device for preparing ethylene and propylene by catalytic conversion of petroleum hydrocarbon.

The invention adopts the following technical scheme:

a method for preparing ethylene and propylene by catalytic conversion of petroleum hydrocarbon comprises the following reaction processes: heavy oil macromolecules are subjected to catalytic cracking conversion under mild conditions to form intermediate molecules with C5-C12 as main components, and then the intermediate molecules are subjected to catalytic cracking and thermal cracking combined conversion under high-severity conditions to produce ethylene and propylene; the heavy oil catalytic cracking and cracking conversion of the method are carried out in a reactor, the reactor is divided into two stages of heat supply and catalyst circulation from top to bottom, the reactor is divided into two reaction zones from top to bottom, namely a catalytic cracking lower reaction zone and a catalytic cracking upper reaction zone from an upper regenerant (namely an upper catalyst) and a heat supply position (namely an upper regenerant inlet from the bottom), the lower part of the reactor is the catalytic cracking lower reaction zone, or a heavy petroleum hydrocarbon low-temperature catalytic cracking reaction zone or a low-temperature reaction zone with high boiling point, heavy component macromolecules are carried out to carry out the catalytic cracking reaction of converting the heavy component macromolecules into intermediate components from C5 to C12, and intermediate raw materials are provided for preparing ethylene and propylene; the upper part of the reactor is a catalytic cracking upper reaction zone, or a high-temperature cracking olefin preparation reaction zone or a high-temperature reaction zone, a catalyst (namely an upper regenerant) entering from an entry point above the reactor provides heat to further improve the reaction temperature of the catalytic cracking upper reaction zone to form the high-temperature reaction zone, and the middle component mainly containing C5-C12 is subjected to catalytic cracking and thermal cracking combined reaction under the harsher conditions of higher temperature and larger catalyst-to-oil ratio to convert the petroleum hydrocarbon raw material into ethylene and propylene; the selective reaction of heavy petroleum hydrocarbon with high boiling point in the upper and lower reactors with two-stage heat supply and two-stage catalyst supply is realized, the gradually-increased reaction mode of the reaction temperature is adapted to the gradually-decreased molecular structure of the molecular weight of reactants and the change of the requirement on the reaction condition, and the efficiency of preparing olefin and the selectivity of target products are improved;

heavy petroleum hydrocarbon sequentially enters a lower catalytic cracking reaction zone with lower temperature and an upper catalytic cracking reaction zone with high temperature to sequentially realize low-temperature catalytic cracking reaction and high-temperature olefin cracking reaction, and a catalyst of a regenerator respectively enters the lower catalytic cracking reaction zone and the upper catalytic cracking reaction zone to realize gradual temperature rise in the reaction process in a graded heat supply mode; heavy petroleum hydrocarbon is firstly subjected to catalytic cracking reaction of high-boiling-point heavy components in a low-temperature reaction zone, catalytic cracking conversion, decarburization and demetalization of the heavy components and macromolecules are preliminarily completed, intermediate components mainly comprising high-olefin gasoline and diesel oil components are generated, the intermediate products and a catalyst upwards enter a high-temperature reaction zone above a reactor, heat and the catalyst are continuously provided for the zone through another path of the catalyst from a regenerator, the temperature of a reactant and the ratio of the reactant to the gasoline are improved, and the catalytic cracking reaction of the heavy components and the cracking conversion of the intermediate components and the micromolecules are realized; the reaction process comprises the following steps:

(1) the heavy petroleum hydrocarbon is atomized by steam and then enters a lower catalytic cracking reaction zone at the lower part of the reactor, and the catalytic cracking reaction is carried out under the environment of a lower regenerant introduced from the regenerator through a lower regeneration vertical pipe; the reaction zone under the catalytic cracking, namely the low-temperature reaction zone, is carried out under the condition favorable for catalytic conversion of high-boiling-point heavy components, the reaction temperature is 525-620 ℃, and the reaction time is 0.5-5.0 s; the actual reaction temperature and the catalyst oil ratio are controlled by the amount of catalyst entering the low temperature reaction zone from the lower regeneration standpipe;

(2) after the heavy petroleum hydrocarbon finishes the low-temperature catalytic cracking reaction, the product and the catalyst generated in the lower catalytic cracking reaction zone flow upwards and enter the upper catalytic cracking reaction zone, the upper regenerant introduced from the regenerator through the upper regeneration vertical pipe enters the upper catalytic cracking reaction zone, heat is provided for the upper catalytic cracking reaction zone, the temperature and the catalyst-oil ratio are increased, and the combined reaction of catalytic cracking and thermal cracking is continuously carried out to generate an olefin product; the reaction temperature of the catalytic cracking upper reaction zone is 550-750 ℃, the reaction time is 0.1-5.0 s, the absolute pressure of the reaction pressure is 0.20-0.40 MPa, and the actual reaction temperature and the catalyst-oil ratio are controlled by the amount of the catalyst entering the catalytic cracking upper reaction zone from the upper regeneration vertical pipe;

(3) and the reacted material flow enters a settler for gas-solid separation to obtain a reaction product, and the separated catalyst enters a regenerator for regeneration after steam stripping in a steam stripping section for recycling.

In the above method for preparing ethylene and propylene by catalytic conversion of petroleum hydrocarbon, further, the heavy petroleum hydrocarbon is one or a mixture of vacuum wax oil, (atmospheric) residual oil, coker wax oil, deasphalted oil, hydrogenated wax oil (hydrotreated wax oil), hydrogenated residual oil (hydrotreated residual oil), and crude oil; the boiling point is higher than 320 ℃.

In the above method for preparing ethylene and propylene by catalytic conversion of petroleum hydrocarbon, further, the petroleum hydrocarbon raw material further comprises independent light hydrocarbon;

when independent light hydrocarbon raw materials in the petroleum hydrocarbon raw materials need to be processed in a reactor, the light hydrocarbon directly or after being heated enters the reactor to be subjected to catalytic conversion to prepare olefin, or the light hydrocarbon enters an additional second reactor, the second reactor and the reactor share a settler and a regenerator, and material flow formed by the reaction of the light hydrocarbon in the second reactor R20 enters the settler.

Preferably, the light hydrocarbon is one or a mixture of naphtha, C4, C5 and hydrocatalytic (cracked) diesel components, the boiling point is lower than 360 ℃, or the light hydrocarbon is hydrocracked tail oil.

Preferably, when the light hydrocarbon reacts in the reactor, the light hydrocarbon reacts in the catalytic cracking upper reaction zone, i.e. the light hydrocarbon directly enters the high-temperature reaction zone of the reactor to perform catalytic cracking reaction with the reaction product stream from the low-temperature reaction zone, and is converted into ethylene and propylene under high-severity conditions.

Preferably, when the light hydrocarbon reacts in the second reactor, the heavy oil or recycle oil is supplemented at the downstream of the second reactor for increasing the heat supplement of coke formation and oil gas temperature reduction.

In the present invention, it is preferable that the upper and lower regeneration zones, i.e., the lower regeneration zone and the upper regeneration zone, are disposed below the dilute phase zone of the regenerator, and the regenerant is supplied to the reactor through the upper regeneration zone.

In the invention, preferably, an upper regeneration zone and a lower regeneration zone, namely a lower regeneration zone and an upper regeneration zone, are arranged below a dilute phase zone of a regenerator of the regenerator, the upper regeneration zone is a dense-phase fluidized bed regeneration zone, and the carbon content and the temperature of catalysts in the two regeneration zones are adjusted by adjusting the catalyst amount and the distribution of the regenerated oxygen amount or air amount of the lower regeneration zone and the upper regeneration zone; the spent catalyst from the stripping section enters an upper regeneration zone, the catalyst, namely a lower regeneration agent, is provided to a lower catalytic cracking reaction zone through a lower regeneration zone, and the catalyst, namely an upper regeneration agent, is provided to an upper catalytic cracking reaction zone through an upper regeneration zone (a fluidized bed regeneration zone). During specific implementation, the carbon content and the temperature of the catalysts in the two regeneration zones are adjusted by adjusting the amount of the catalysts in the two regeneration zones of the regenerator and the distribution of the amount of the regenerated oxygen or the amount of air, so that heat is supplied to the high-temperature reaction zone and the catalysts with different carbon contents are supplied to the two reaction zones; when catalysts having different carbon contents are supplied to the reactor, a catalyst having a high carbon content is supplied to the upper pyrolysis reaction zone.

The method for preparing ethylene and propylene by catalytic conversion of petroleum hydrocarbon further comprises the following steps that the temperature of the lower regenerant is 660-750 ℃, and the carbon content of the catalyst is lower than 0.10%; the temperature of the upper regenerant is 700-780 ℃, and the carbon content of the catalyst is lower than 0.5%.

The method for preparing ethylene and propylene by catalytic conversion of petroleum hydrocarbon further supplements heavy oil or recycle oil at the downstream of the catalytic cracking upper reaction zone or/and the stripping section for increasing coke formation heat supplement and oil gas temperature reduction.

In the present invention, different regeneration methods are required according to the requirements of the reaction on the temperature and carbon content of the catalyst. When the catalysts entering different reaction zones of the reactor do not need to control the carbon content respectively or do not need to use the catalysts with different carbon contents in different reaction zones for reaction or the temperatures of the catalysts entering different reaction zones are obviously different, the regenerator adopts a conventional coke-burning tank regeneration mode, the lower regeneration zone is a fast fluidized bed, the upper regeneration zone is a dense-phase fluidized bed, and the catalysts are provided for the reactor from the dense-phase fluidized bed;

when the catalysts entering different reaction zones of the reactor need to respectively control the carbon content or need different reaction zones to use catalysts with different carbon contents for reaction, or the temperatures of the catalysts entering different reaction zones are obviously different, the regenerator adopts a regeneration form of an upper and a lower double-phase fluidized bed, the catalyst amount of the two fluidized bed regeneration zones or the entering amount of burnt oxygen or air is adjusted and controlled, so that the catalyst temperature and the carbon content of the two regeneration zones are different, and the catalysts with different carbon contents and temperatures are provided for the reactor from the dense-phase fluidized bed according to the needs;

the stripped spent catalyst enters an upper regeneration zone, the catalyst in the upper regeneration zone is a semi-regenerant containing carbon moderately, the catalyst in the lower regeneration zone is a regenerated catalyst, and the temperature of the upper regeneration zone is higher than that of the lower regeneration zone; providing catalyst from the upper regeneration zone to the upper catalytic cracking reaction zone of the reactor, and providing catalyst from the lower regeneration zone to the lower catalytic cracking reaction zone;

the reaction zone under catalytic cracking is mainly used for catalytic conversion of macromolecular heavy oil; the catalytic cracking upper reaction zone mainly performs the reaction of cracking to prepare ethylene, propylene and aromatic hydrocarbon.

In the method, the circulating oil separated from the reaction product in the fractionating tower, including heavy circulating oil and light circulating oil, can be hydrogenated and then returned to the reactor; after hydrogenation, heavy cycle oil is firstly reacted in a catalytic cracking lower reaction zone; the light cycle oil is firstly reacted in a lower catalytic cracking reaction zone, or directly reacted in an upper catalytic cracking reaction zone, or reacted in a second reactor.

The invention also provides a device for realizing the method, and the adopted scheme is as follows:

a device for preparing ethylene and propylene by catalytic conversion of petroleum hydrocarbon is provided with a reactor, a regenerator, a settler and a stripping section, wherein the regenerator and the settler are arranged in parallel, the reactor is arranged in the form of an upper-lower subarea reactor with upper and lower catalyst circulation paths and twice heat supply, and comprises a lower catalytic cracking reaction zone at the lower part and an upper catalytic cracking reaction zone at the upper part, the lower catalytic cracking reaction zone is used for low-temperature catalytic cracking reaction, and the upper catalytic cracking reaction zone is used for high-temperature olefin cracking reaction; a heavy petroleum hydrocarbon inlet is arranged at the lower part of the catalytic cracking lower reaction zone; the lower regenerant inlet at the lower part of the lower catalytic cracking reaction zone is communicated with the lower regenerant outlet of the regenerator through a lower regeneration vertical pipe, and the upper regenerant inlet at the lower part of the upper catalytic cracking reaction zone is communicated with the upper regenerant outlet of the regenerator through an upper regeneration vertical pipe.

When the device for preparing ethylene and propylene by catalytic conversion of petroleum hydrocarbon is specifically implemented, the regenerator adopts two regions arranged in series from top to bottom for regeneration, the upper regeneration region is in a fluidized bed form, the upper and lower regeneration regions, namely the lower regeneration region and the upper regeneration region, are arranged below the dilute phase region of the regenerator, and the lower regenerant outlet and the upper regenerant outlet are both arranged in the upper regeneration region, so that a regenerant is provided for the reactor through the upper regeneration region; or an upper regeneration zone and a lower regeneration zone, namely a lower regeneration zone and an upper regeneration zone, are arranged below a dilute phase zone of the regenerator, and the upper regeneration zone is a dense-phase fluidized bed regeneration zone; the lower regenerant outlet is arranged in the lower regeneration zone to supply the catalyst, namely the lower regenerant, to the catalytic cracking lower reaction zone through the lower regeneration zone, and the upper regenerant outlet is arranged in the upper regeneration zone to supply the catalyst, namely the upper regenerant, to the catalytic cracking upper reaction zone through the fluidized bed regeneration zone of the upper regeneration zone.

The device for preparing ethylene and propylene by catalytic conversion of petroleum hydrocarbon is further provided with a second reactor, and the second reactor and the reactor share a settler, a stripping section and a regenerator; a light hydrocarbon inlet is arranged at the lower part of the second reactor; a third regenerant inlet at the lower portion of the second reactor is communicated with a third regenerant outlet of the regenerator through a third regeneration riser; in particular embodiments, the third regenerant outlet is preferably located in the upper regeneration zone. The second reactor is used for realizing independent reaction of light hydrocarbon.

In the invention, the mass ratio of the steam in the low-temperature reaction zone to the heavy petroleum hydrocarbon is 5-30%, and the mass ratio of the steam in the high-temperature reaction zone to the heavy petroleum hydrocarbon is 15-50%.

During specific implementation, a steam generator can be arranged behind a product outlet of the reaction settler, steam is generated by utilizing heat of high-temperature product material flow, the product material flow is cooled or quenched, and the engineering design unit of the steam generator is mastered.

Effects of the invention

The invention provides a method for preparing olefin by gradually raising temperature and converting with two-stage temperature gradient from 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 (C18 or more) are firstly cracked to generate middle molecular (C5-C12) products such as gasoline, diesel oil and the like, and the lower cracking temperature can highlight the catalytic cracking reaction, generally 490-530 ℃; part of gasoline and diesel oil is cracked into C3-C8 at 525-600 deg.c; at higher temperature, 600-750 ℃, C3-C8 will further crack into C1, C2, C3 small molecule products. The invention follows the reaction rule and arranges two stages of temperature gradients which are gradually heated in series: low temperature zone, high temperature zone. The invention reduces the yield of low-value target products such as coke and dry gas on the premise of lower energy consumption; the yield of high value target products, such as ethylene, is increased.

The method of the invention controls the ratio of the catalyst to the oil and the temperature in the reaction process, particularly realizes the reaction along with the reaction, the ratio of the catalyst to the oil and the temperature are gradually increased, and the reaction severity is gradually increased, so that the reaction conditions are adapted to the reaction chemical conditions that the petroleum hydrocarbon molecules are gradually reduced and the required reaction severity is gradually increased in the cracking process of the heavy petroleum hydrocarbon; the invention also well optimizes the common conversion effect of heavy components and light hydrocarbon raw materials with different properties, avoids over-cracking of small molecular light hydrocarbon, and ensures both the cracking conditions of the heavy components and the light hydrocarbon; the method improves efficiency and increases selectivity of target products.

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;

the numbering in the figures illustrates:

an R10 reactor; r11 catalyst pre-lift gas; R11A catalyst pre-lift gas inlet, R12 heavy petroleum hydrocarbon; an inlet of R12A heavy petroleum hydrocarbon, atomized steam of R13 raw material, a regeneration slide valve under R14, a regenerant inlet under R14A, steam supplemented in a reaction zone under R15A, steam supplemented in a reaction zone above R15B, a reaction zone under R17 catalytic cracking, an upper reaction zone of R18 catalytic cracking, heavy oil or recycle oil supplemented in a reactor of R19, a second reactor of R20 or a light hydrocarbon reactor, and pre-lift gas of a second catalyst of R21; r22 light hydrocarbons; r23 light hydrocarbon atomizing steam; r24 on the regeneration slide valve, R24A on the regenerant inlet; r29 second reactor make-up heavy oil or recycle oil, R34 third regeneration slide valve, R34A third regenerant inlet;

an S10 stripping section, S11 stripping means; s12 spent catalyst slide valve, S12A spent riser or spent catalyst conveying pipe, and S13 steam stripping; s19 stripping make-up heavy oil or recycle oil;

a D10 settler, a D11 settling cyclone; d12 reaction product, D12A reaction settler product outlet;

a G10 regenerator, a G11 catalyst regeneration gas, a G11A regeneration gas inlet, a G12 upper regeneration zone, a G12A spent agent inlet, G13 fuel oil, a G14 lower regeneration vertical pipe or lower regeneration agent conveying pipe, a G14A lower regeneration agent outlet, a G15 regenerator dilute phase zone, a G16 regeneration cyclone separator, G17 burnt flue gas, a G17A flue gas outlet, a G18 second regeneration gas and a G19 lower regeneration zone;

g24, a regeneration vertical pipe or a regeneration agent conveying pipe, and G24A, a regeneration agent outlet; g34 third regenerant riser, G34A third regenerant outlet;

an A0 heating furnace, an A1 heat exchanger, a T10 fractionating tower and a T20 hydrogenation reactor; HCO heavy cycle oil, LCO light cycle oil and CO-H hydrogenated cycle oil; h₂Hydrogen gas;

TIC temperature display control; controlling the outlet temperature of the lower reaction zone of TIC-1, controlling the outlet temperature of the upper reaction zone of TIC-2, and controlling the outlet temperature of the second reactor of TIC-3.

Detailed Description

The technical solutions of the present invention are described below in the following embodiments and examples, but the scope of the present invention is not limited thereto.

The first implementation mode comprises the following steps:

in the method for preparing ethylene and propylene by catalytic conversion of petroleum hydrocarbon according to the embodiment, the catalytic conversion device shown in fig. 1 is adopted, the reactor R10, the regenerator G10, the settler D10 and the stripping section S10 are arranged, and the heavy petroleum hydrocarbon is used as a raw material, and in the specific implementation, the heavy petroleum hydrocarbon can be one or a mixture of vacuum wax oil, residual oil, coking wax oil, deasphalted oil, hydrotreated wax oil, hydrotreated residual oil and crude oil, and in the specific implementation, the boiling point of the heavy petroleum hydrocarbon is preferably higher than 320 ℃;

the regenerator G10 and the settler D10 are arranged in parallel, the outlet of the reactor R10 is communicated with a settling cyclone D11 in the settler D10, the stripping section S10 is arranged below the settler D10, a stripping component S11 is arranged in the stripping section S10, and stripping steam S13 is introduced into the stripping section S10 to realize the stripping of the catalyst;

the reactor R10 is set into the form of upper and lower subarea reactors with upper and lower catalyst circulation and twice heat supply, and comprises a lower catalytic cracking reaction zone R17 at the lower part and an upper catalytic cracking reaction zone R18 at the upper part, wherein the lower catalytic cracking reaction zone R17 is used for low-temperature catalytic cracking reaction, and the upper catalytic cracking reaction zone R18 is used for high-temperature olefin cracking reaction; a lower regenerant inlet R14A at the lower part of the lower catalytic cracking reaction zone R17 is communicated with a lower regenerant outlet G14A of a regenerator G10 through a lower regeneration riser G14, and an upper regenerant inlet R24A at the lower part of the upper catalytic cracking reaction zone R18 is communicated with an upper regenerant outlet G24A of the regenerator G10 through an upper regeneration riser G24; a heavy petroleum hydrocarbon inlet R12A is arranged at the lower part of the reactor R10 to introduce the heavy petroleum hydrocarbon R12 and the raw material atomizing steam R13, and a catalyst pre-lifting gas inlet R11A is arranged at the bottom of the reactor R10 to introduce a catalyst pre-lifting gas R11; the top of the settler D10 was provided with a reaction settler product outlet D12A to withdraw reaction product D12;

in specific implementation, the regenerator G10 adopts two-zone regeneration arranged in series from top to bottom, an upper regeneration zone G19 and an upper regeneration zone G12 are arranged below a dilute phase zone G15 of the regenerator, in specific implementation, the lower regeneration zone G19 adopts a form of a fast fluidized bed of a coking tank, the upper regeneration zone G12 adopts a form of a dense-phase fluidized bed, namely the regenerator G10 adopts a form of serial regeneration of the fast fluidized bed of the coking tank and the dense-phase fluidized bed, and a lower regenerant outlet G14A and an upper regenerant outlet G24A are arranged in an upper regeneration zone G12, so that a regenerant is supplied to a reactor R10 through the upper regeneration zone G12; the lower part of the stripping section S10 is communicated with a lower regeneration zone G19 of a regenerator G10 through a spent riser S12A from a spent agent inlet G12A, and a spent catalyst slide valve S12 is arranged on a spent riser S12A;

in specific implementation, an upper regeneration zone G12 of the regenerator G10 is communicated with a lower regeneration agent inlet R14A at the lower part of a catalytic cracking lower reaction zone R17 through a lower regeneration standpipe G14 from a lower regeneration agent outlet G14A, and a lower regeneration slide valve R14 is arranged on a lower regeneration standpipe G14;

the upper regeneration zone G12 is communicated with an upper regenerant inlet R24A at the lower part of the catalytic cracking upper reaction zone R18 through an upper regenerant outlet G24A and an upper regeneration riser G24, and an upper regeneration slide valve R24 is arranged on an upper regeneration riser G24;

a regenerator cyclone separator G16 is arranged in a regenerator dilute phase zone G15 of the regenerator G10, flue gas G17 after the regenerator is burnt is discharged from a flue gas outlet G17A at the top of the regenerator G10, and catalyst regeneration gas G11 is introduced from a regeneration gas inlet G11A at the bottom of the regenerator G10; second regeneration gas G18 is introduced into regenerator G10 from the lower portion of upper regeneration zone G12;

introducing lower reaction zone make-up steam R15A above a lower regenerant inlet R14A in the lower portion of the lower catalytic cracking reaction zone R17 and upper reaction zone make-up steam R15B above an upper regenerant inlet R24A in the lower portion of the upper catalytic cracking reaction zone R18; introducing a reactor supplement heavy oil or recycle oil R19 at the downstream of the catalytic cracking upper reaction zone R18, introducing a stripping supplement heavy oil or recycle oil S19 at a stripping section S10, and realizing the increase of green coke heat supplement and oil gas temperature reduction; the lower part of the lower regeneration zone G19 was fed with fuel oil G13.

In the invention, the catalyst of the regenerator G10 enters a lower catalytic cracking reaction zone R17 and an upper catalytic cracking reaction zone R18 respectively, and the gradual temperature rise in the reaction process is realized in a graded heat supply mode; the specific implementation process comprises the following steps:

(1) the preheated heavy petroleum hydrocarbon R12 is atomized by raw material atomizing steam R13 and then enters a catalytic cracking lower reaction zone R17 at the lower part of a reactor R10, a lower catalyst from a lower regeneration vertical pipe G14 and an upper regeneration zone G12 of a regenerator enters a catalytic cracking lower reaction zone R17 from a lower regenerant inlet R14A, is conveyed upwards to contact with the raw material under the action of catalyst pre-lifting gas R11, and the heavy petroleum hydrocarbon R12 is subjected to catalytic cracking conversion under mild conditions in the catalyst environment to form an intermediate product mainly comprising C5-C12; the reaction temperature of the R17 reaction zone under catalytic cracking is 525-620 ℃, and the reaction time is 0.5-5.0 s;

(2) after the low-temperature catalytic cracking reaction of heavy petroleum hydrocarbon R12 is completed, a product generated in a lower catalytic cracking reaction zone R17 and a catalyst flow upwards together to enter an upper catalytic cracking reaction zone R18, a new catalyst, namely an upper regenerant introduced from a regenerator G10 through an upper regeneration vertical pipe G24 enters an upper catalytic cracking reaction zone R18 and is conveyed to an upper catalytic cracking reaction zone R28 by a material flow from the lower catalytic cracking reaction zone R17, the new catalyst further provides heat for the upper catalytic cracking reaction zone R18 and improves the material flow temperature and oil ratio to form a high-temperature cracking reaction condition with higher severity, the product from the lower catalytic cracking reaction zone continues to perform the combined reaction of catalytic cracking and thermal cracking, and low-carbon-number small-molecule products such as ethylene, propylene and the like; the reaction temperature of the upper catalytic cracking reaction zone R18 is 550-750 ℃, the reaction time is 0.1-5.0 s, the absolute pressure of the reaction pressure is 0.20-0.40 MPa, and the actual reaction temperature is controlled by the catalyst amount entering the upper catalytic cracking reaction zone R18;

(3) the reacted material flow enters a precipitator D10 for gas-solid separation to obtain a reaction product D12, and the reaction product D12 is sent out from a product outlet D12A of the reaction precipitator and enters a subsequent treatment part; after being separated by a settling cyclone separator D11, the reacted catalyst is stripped in a stripping section S10 and then enters a lower regeneration area G19 of a regenerator G10 through a spent riser S12A and a spent agent inlet G12A for regeneration and recycling.

In specific implementation, after the reaction product D12 leaves the catalytic conversion device shown in FIG. 1, quenching and cooling are firstly carried out, the continuous reaction is stopped, the subsequent treatment and the coking of a conveying pipeline are avoided, and then the product fractionation is carried out; the product gas can be quenched by directly generating steam, or quenched by directly mixing other heat exchange and low-temperature media; quenching and fractionation, etc., are well known to the skilled engineer.

In specific implementation, the raw oil can be heated by a heating furnace.

Example 1

The device and the process are shown in figure 1, and the implementation parameters are as follows: the heavy petroleum hydrocarbon is vacuum wax oil, the density is 0.89, the hydrogen content is 13.2 percent (weight), the carbon residue is 4.0 percent, and the saturated hydrocarbon is 60 percent;

the preheating temperature of raw oil is 220 ℃;

the reaction device is a settler and a regenerator which are arranged in parallel, the regenerator adopts a serial regeneration form of a fast fluidized bed and a dense-phase fluidized bed of a coke burning tank, and the reactor is a riser reactor;

reaction conditions of a reaction zone under catalytic cracking: the reaction temperature TIC-1 is controlled to 530 ℃, and the reaction time is 1.1s (second); the catalyst conveying gas is steam, the amount of the steam is 3% of the heavy petroleum hydrocarbon, and the raw material atomized steam is 7% of the raw material; the catalyst (namely the lower regenerant) entering from the inlet of the lower regenerant is used as the regenerant, the carbon content is 0.02 percent, and the temperature of the lower regenerant is 720 ℃;

reaction conditions in the catalytic cracking upper reaction zone: the catalyst (namely the upper regenerant) entering from the upper regenerant inlet is the regenerant, the carbon content is 0.02 percent, the temperature is 725 ℃, the reaction temperature TIC-2 is controlled to be 665 ℃, the reaction time is 1.2 seconds, the steam proportion is 30 percent, and the supplementary steam is 20 percent of the raw material;

the reaction process is as follows:

atomizing the raw materials by using steam, then feeding the atomized raw materials into a lower catalytic cracking reaction zone, and carrying out heavy oil catalytic cracking conversion under the heat provided by a lower regenerant and a catalyst environment to realize the cracking conversion of heavy oil macromolecules to intermediate molecules, so as to obtain an intermediate component raw material with the molecular weight of 100-200 as far as possible and provide an intermediate raw material for further conversion into propylene and ethylene; the gas material flow and the catalyst generated in the reaction zone under the catalytic cracking continuously flow upwards and enter the high-temperature reaction zone; the high-temperature catalyst from the regenerator, namely the upper catalyst, enters the catalytic cracking upper reaction zone, is conveyed upwards by the gas from the low-temperature reaction zone to enter the high-temperature reaction zone, further provides heat for the high-temperature reaction zone, improves the reaction temperature in the high-temperature reaction zone, and realizes the conversion reaction to olefin by combining the catalytic reaction and the thermal reaction of the intermediate component; the reaction material flow in the high-temperature reaction zone is subjected to gas-solid separation in a settler through a gas-solid separator, and the gas with the separated catalyst flows out of the settler and enters a subsequent treatment system;

the catalyst to be regenerated separated from the settler enters a regenerator for catalyst regeneration after being stripped in a stripping section, enters a lower regeneration zone firstly, and then is conveyed to an upper regeneration zone by coke-burning gas, and the catalyst enters a reactor after being regenerated for recycling;

regeneration of the catalyst, gas-solid separation, and subsequent oil and gas treatment are common techniques, well known to the skilled artisan and not described further.

Example 1 the product distribution is shown in table 1:

table 1 example 1 product distribution

Components	Unit% (weight)
		Dry gas	34.75
Wherein:
		H	0.14
methane	11.70
		Ethane (III)	4.75
Ethylene	17.00
		Liquefied gas	30.67
Wherein:
		propane	2.11
Propylene (PA)	18.61
		Butane	1.39
Butene (butylene)	8.55
		Gasoline (gasoline)	13.45
Diesel oil	9.1
		Heavy oil	3.2
Coke	8.83

The second embodiment:

the method for producing ethylene and propylene by catalytic conversion of petroleum hydrocarbon according to the present embodiment employs the catalytic converter shown in fig. 2, which is provided with a reactor R10, a regenerator G10, a settler D10 and a stripping section S10, and uses heavy petroleum hydrocarbon as a raw material;

the regenerator G10 adopts two regions arranged in series up and down for regeneration, the lower regeneration region G19 and the upper regeneration region G12 both adopt a dense-phase fluidized bed form, the lower part of a stripping section S10 is communicated with the upper regeneration region G12 of the regenerator G10 through a spent riser S12A and a spent agent inlet G12A, spent catalyst firstly enters the upper dense-phase fluidized bed regeneration region, namely the upper regeneration region G12, and then enters the lower dense-phase fluidized bed regeneration region, namely the lower regeneration region G19 for regeneration;

a lower regeneration zone G19 of the regenerator G10 is communicated with a lower regenerant inlet R14A at the lower part of a lower catalytic cracking reaction zone R17 through a lower regeneration vertical pipe G14 from a lower regenerant outlet G14A, and a catalyst is supplied to the lower catalytic cracking reaction zone R17 from a lower regeneration zone G19, wherein the temperature of the catalyst is 700 ℃, and carbon content is 0.02%; the upper regeneration zone G12 is communicated with an upper regenerant inlet R24A at the lower part of the catalytic cracking upper reaction zone R18 through an upper regenerant outlet G24A and an upper regeneration vertical pipe G24, and catalyst is supplied to the catalytic cracking upper reaction zone R18 from the upper regeneration zone G12, the temperature of the catalyst is 740 ℃, and carbon content is 0.15%; introducing fuel oil G13 into the lower part of the upper regeneration zone G12;

a gas lead-out pipeline of the reaction product D12 is provided with a heat exchanger A1, a fractionating tower T10 and a hydrogenation reactor T20; the heavy petroleum hydrocarbon R12 and a reaction product D12 exchange heat in a heat exchanger A1, the heavy petroleum hydrocarbon R12 enters a reactor R10 to participate in catalytic conversion after being preheated, the reaction product D12 is subjected to heat exchange and temperature reduction by a heat exchanger A1, then sequentially passes through a fractionating tower T10 and a hydrogenation reactor T20, heavy cycle oil HCO obtained by separation in a fractionating tower T10 is sent out of a device, and light cycle oil LCO is hydrogenated to hydrogenated cycle oil CO-H which returns to the reactor R10 from the upper part of a heavy petroleum hydrocarbon inlet R12A to be subjected to catalytic conversion again.

The other parts of the device structure are the same as the first embodiment. The separation of components and the hydrogenation of the fractionating tower and the cycle oil are well known to the skilled person and will not be described in detail.

The third embodiment is as follows:

the method for preparing ethylene and propylene by catalytic conversion of petroleum hydrocarbon in the embodiment adopts the catalytic conversion device shown in fig. 3, is provided with a reactor R10, a regenerator G10, a settler D10 and a stripping section S10, adopts heavy petroleum hydrocarbon and light hydrocarbon as reaction raw materials, the light hydrocarbon is one or a mixture of naphtha, hydrogenated catalytic cracking diesel oil, C4 and C5 components, and the boiling point is lower than 360 ℃;

the lower regeneration zone G19 of the regenerator G10 is communicated with a lower regenerant inlet R14A at the lower part of the lower catalytic cracking reaction zone R17 through a lower regenerant outlet G14A via a lower regeneration riser G14, and catalyst is supplied to the lower catalytic cracking reaction zone R17 from a lower regeneration zone G19; the upper regeneration zone G12 is communicated with an upper regenerant inlet R24A at the lower part of the catalytic cracking upper reaction zone R18 through an upper regenerant outlet G24A via an upper regeneration standpipe G24, and catalyst is supplied to the catalytic cracking upper reaction zone R18 from an upper regeneration zone G12;

introducing fuel oil G13 into the lower part of the upper regeneration zone G12;

a light hydrocarbon inlet is arranged above an upper regenerant inlet R24A of the catalytic cracking upper reaction zone R18; a heat exchanger A1 was provided on the gas outlet line of the reaction product D12;

the light hydrocarbon R22 and the reaction product D12 exchange heat in a heat exchanger A1, the light hydrocarbon R22 directly enters a catalytic cracking upper reaction area R18 after being preheated to participate in the reaction in a reactor R10, and the light hydrocarbon R22 is atomized by light hydrocarbon atomization steam R23;

in specific implementation, heavy petroleum hydrocarbon R12 firstly enters a catalytic cracking lower reaction zone R17 for low-temperature reaction; the product of the catalytic cracking lower reaction zone R17 and the catalyst flow upwards to enter the catalytic cracking upper reaction zone R18, and flow upwards together with the light hydrocarbon R22 to perform high-temperature reaction with increased temperature;

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

The fourth embodiment:

in the method for preparing ethylene and propylene by catalytic conversion of petroleum hydrocarbon according to the embodiment, the catalytic conversion device shown in fig. 3 is adopted, the reactor R10, the regenerator G10, the settler D10 and the stripping section S10 are arranged, heavy petroleum hydrocarbon and light hydrocarbon are used as reaction raw materials, and the light hydrocarbon is hydrocracking tail oil; hydrocracking tail oil is a fixed and well-known technical term in the field, and it is known that after crude oil is subjected to hydrocracking treatment, the tail oil, namely hydrocracking tail oil saturated hydrocarbon (mainly C20-C30 normal paraffin) content is up to above 96.8%, aromatic hydrocarbon content is less than 1%, sulfur, nitrogen and other impurities are low, and the tail oil is high-quality oil, and the nature of the hydrocracking tail oil is related to raw oil adopted during hydrocracking, in the invention, during specific implementation, the BMCI value of the hydrocracking tail oil capable of performing catalytic conversion is less than or equal to 20;

the regenerator G10 is a type of regeneration in which a quick fluidized bed and a dense-phase fluidized bed of a coke burning tank are connected in series;

providing a second reactor R20, the second reactor R20 sharing a settler D10, a stripping section 10 and a regenerator G10 with reactor R10; a third regenerant inlet R34A at the lower portion of the second reactor R20 is in communication with a third regenerant outlet G34A of the regenerator G10 through a third regeneration standpipe G34; a third regenerant outlet G34A was provided in the upper regeneration zone G12; a light hydrocarbon inlet is arranged at the lower part of the second reactor R20 to introduce light hydrocarbon R22, and a second catalyst pre-lift gas R21 is introduced at the lower part of the second reactor R20;

the second reactor R20 is used for realizing independent reaction of light hydrocarbon R22, and the second reactor R20 is introduced downstream to supplement heavy oil or recycle oil R29;

a heating furnace A0 is arranged, a light hydrocarbon R22 enters a second reactor R20 after being preheated in the heating furnace A0 to realize independent catalytic conversion, material flow formed by reaction in the second reactor R20 and material flow formed by reaction in the reactor R10 enter a settler D10 together to separate out a catalyst, and then a reaction product D12 is obtained;

heavy petroleum hydrocarbon R12 is preheated in a heating furnace A0 and enters a reactor R10 to participate in catalytic conversion;

in the present embodiment, the density of the hydrocracked tail oil is 0.82, and the BMCI value is 10.6; the hydrocracking tail oil accounts for 10% of the heavy petroleum hydrocarbon; the other parts of the device structure are the same as the first embodiment.

Claims

1. A method for preparing ethylene and propylene by catalytic conversion of petroleum hydrocarbon is characterized in that a reactor (R10) is provided with an upper reaction zone and a lower reaction zone, namely a lower catalytic cracking reaction zone (R17) and an upper catalytic cracking reaction zone (R18), heavy petroleum hydrocarbon (R12) sequentially enters a lower catalytic cracking reaction zone (R17) at a low temperature and an upper catalytic cracking reaction zone (R18) at a high temperature to sequentially realize the low-temperature catalytic cracking reaction and the high-temperature cracking reaction, a catalyst of a regenerator (G10) respectively enters the lower catalytic cracking reaction zone (R17) and the upper catalytic cracking reaction zone (R18) to realize gradual temperature rise in the reaction process in a graded heat supply mode; the reaction process comprises the following steps:

(1) the heavy petroleum hydrocarbon (R12) is atomized by steam and then enters a lower catalytic cracking reaction zone (R17) at the lower part of the reactor (R10) to carry out catalytic cracking reaction under the environment of a lower regenerant introduced from a regenerator (G10) through a lower regeneration riser (G14); the reaction temperature of the catalytic cracking lower reaction zone (R17) is 525-620 ℃, the reaction temperature is controlled by the regeneration dosage from the lower regeneration vertical pipe (G14), and the reaction time is 0.5-5.0 s;

(2) after the heavy petroleum hydrocarbon (R12) finishes low-temperature catalytic cracking reaction, products and catalyst generated in a lower catalytic cracking reaction zone (R17) flow upwards to enter an upper catalytic cracking reaction zone (R18), an upper regenerant introduced from a regenerator (G10) through an upper regeneration vertical pipe (G24) enters an upper catalytic cracking reaction zone (R18), heat is provided for the upper catalytic cracking reaction zone (R18), the temperature and the catalyst-to-oil ratio are increased, and the combined reaction of catalytic cracking and thermal cracking is continuously carried out; the reaction temperature of the catalytic cracking upper reaction zone (R18) is 550-750 ℃, the reaction time is 0.1-5.0 s, and the absolute pressure of the reaction pressure is 0.20-0.40 MPa; the reaction temperature is controlled by the amount of catalyst from the upper regeneration standpipe (G24);

(3) and the reacted material flow enters a settler (D10) for gas-solid separation to obtain a reaction product (D12), and the separated catalyst enters a regenerator (G10) for regeneration after being stripped in a stripping section (S10) for recycling.

2. The process for the catalytic conversion of petroleum hydrocarbons to ethylene and propylene as claimed in claim 1, wherein the heavy petroleum hydrocarbon (R12) is one or a mixture of vacuum wax oil, residual oil, coker wax oil, deasphalted oil, hydrotreated wax oil, hydrotreated residual oil, and crude oil.

3. The process for the catalytic conversion of petroleum hydrocarbons to ethylene and propylene as claimed in claim 1, wherein the petroleum hydrocarbon feedstock further comprises a separate light hydrocarbon (R22);

or the light hydrocarbon (R22) directly or after being heated enters a reactor (R10) for catalytic conversion to prepare ethylene and propylene, or the light hydrocarbon (R22) enters an additional second reactor (R20), the second reactor (R20) and the reactor (R10) share a settler (D10) and a regenerator (G10), and the light hydrocarbon (R22) reacts in the second reactor (R20) to form a material flow which enters the settler (D10).

4. The method for preparing ethylene and propylene by catalytic conversion of petroleum hydrocarbon as claimed in claim 3, wherein the light hydrocarbon (R22) is one or a mixture of naphtha, hydrogenated catalytic cracking diesel oil, C4 and C5 components, and the boiling point is lower than 360 ℃; or the light hydrocarbon (R22) is hydrocracking tail oil.

5. The process for the catalytic conversion of petroleum hydrocarbons to ethylene and propylene as claimed in claim 3, wherein when the light hydrocarbon (R22) is reacted in the reactor (R10), the light hydrocarbon (R22) is reacted in the catalytic cracking upper reaction zone (R18).

6. The process for the catalytic conversion of petroleum hydrocarbons to ethylene and propylene as claimed in claim 3, wherein the light hydrocarbon (R22) is reacted in the second reactor (R20) and the heavy oil or recycle oil is replenished downstream of the second reactor (R20).

7. The process of claim 1, wherein the lower regenerant temperature is 660 ℃ to 750 ℃ and the catalyst carbon content is less than 0.10%; the temperature of the upper regenerant is 700-780 ℃, and the carbon content of the catalyst is lower than 0.5%.

8. The process for the catalytic conversion of petroleum hydrocarbons to ethylene and propylene as claimed in claim 1, wherein the heavy oil or recycle oil is replenished downstream of the catalytic cracking upper reaction zone (R18) or/and the stripping section (S10).

9. An apparatus for producing ethylene and propylene by catalytic conversion of petroleum hydrocarbon, comprising a reactor (R10), a regenerator (G10), a settler (D10) and a stripping section (S10), wherein the regenerator (G10) and the settler (D10) are arranged in parallel, characterized in that:

the reactor (R10) comprises a lower catalytic cracking reaction zone (R17) at the lower part and an upper catalytic cracking reaction zone (R18) at the upper part, the lower catalytic cracking reaction zone (R17) is used for low-temperature catalytic cracking reaction, and the upper catalytic cracking reaction zone (R18) is used for high-temperature olefin cracking reaction; a heavy petroleum hydrocarbon inlet (R12A) is arranged at the lower part of the catalytic cracking lower reaction zone (R17);

a lower regenerant inlet (R14A) at the lower portion of the lower catalytic cracking reaction zone (R17) is in communication with a lower regenerant outlet (G14A) of the regenerator (G10) through a lower regeneration riser (G14), and an upper regenerant inlet (R24A) at the lower portion of the upper catalytic cracking reaction zone (R18) is in communication with an upper regenerant outlet (G24A) of the regenerator (G10) through an upper regeneration riser (G24).

10. The apparatus for the catalytic conversion of petroleum hydrocarbons to ethylene and propylene according to claim 9, wherein a second reactor (R20) is provided, said second reactor (R20) sharing a settler (D10), a stripping section (S10) and a regenerator (G10) with the reactor (R10); a light hydrocarbon inlet is arranged at the lower part of the second reactor (R20);

a third regenerant inlet (R34A) at the lower portion of the second reactor (R20) is in communication with a third regenerant outlet (G34A) of the regenerator (G10) through a third regeneration standpipe (G34).