阅读说明：本技术 一种生产乙烯、丙烯和芳烃的方法及催化反应系统 (Method for producing ethylene, propylene and aromatic hydrocarbon and catalytic reaction system ) 是由 张执刚 龚剑洪 李�东 魏晓丽 张策 崔琰 刘宪龙 陈昀 于 2020-05-08 设计创作，主要内容包括：一种生产乙烯、丙烯和芳烃的方法及催化反应系统,包括：(1)来自催化裂化分馏塔的碳四组分引入催化裂化反应器,与再生器来的再生催化剂接触反应,反应得到的油气和催化剂混合物进入沉降器进行气固分离,分离出的反应油气经分离系统分离出乙烯、丙烯、芳烃产品和碳四组分；(2)分离出的碳四组分进入芳构化反应器与芳构化催化剂接触反应,反应产物经分离系统分离出乙烯、丙烯和芳烃产品；(3)步骤(1)(2)中干气和液化气中分离得到乙烷、丙烷进入蒸汽裂解炉进行蒸汽裂解,生成乙烯和丙烯。本发明提供的方法乙烯、丙烯、芳烃的产率高,能耗低。(A method for producing ethylene, propylene and aromatic hydrocarbon and a catalytic reaction system, comprising: (1) introducing four carbon components from a catalytic cracking fractionating tower into a catalytic cracking reactor, carrying out contact reaction with a regenerated catalyst from a regenerator, allowing a mixture of oil gas and the catalyst obtained by the reaction to enter a settler for gas-solid separation, and separating the separated reaction oil gas into four carbon components including ethylene, propylene and aromatic hydrocarbon products through a separation system; (2) the separated four carbon components enter an aromatization reactor to contact and react with an aromatization catalyst, and ethylene, propylene and aromatic hydrocarbon products are separated from reaction products through a separation system; (3) and (2) separating the dry gas and the liquefied gas in the step (1) and (2) to obtain ethane and propane, and introducing the ethane and the propane into a steam cracking furnace for steam cracking to generate ethylene and propylene. The method provided by the invention has the advantages of high yield of ethylene, propylene and aromatic hydrocarbon and low energy consumption.)

1. A process for producing ethylene, propylene and aromatic hydrocarbons comprising:

(1) introducing the four carbon components into a catalytic cracking reactor, carrying out contact reaction with a regenerated catalytic cracking catalyst from a regenerator, allowing an oil gas and catalyst mixture obtained by the reaction to enter a settler for gas-solid separation, separating the separated reaction oil gas into dry gas, liquefied gas, gasoline, diesel oil and oil slurry through a first oil-gas separation system, and further separating propylene, propane and four carbon components from the liquefied gas;

(2) the separated four carbon components enter an aromatization reactor to contact and react with an aromatization catalyst, and dry gas, liquefied gas and gasoline rich in aromatic hydrocarbon are separated from reaction products through a second oil-gas separation system, so that ethylene, ethane, propylene, propane and aromatic hydrocarbon products are further separated;

(3) and (3) in the step (1) and the step (2), the propane and the ethane enter a steam cracking furnace for steam cracking to generate ethylene and propylene.

2. The process for producing ethylene, propylene and aromatic hydrocarbons according to claim 1, wherein said four carbon components are from a catalytic cracking unit and comprise C4 olefins and C4 alkanes, wherein the olefin content is greater than 20 wt%.

3. The process for producing ethylene, propylene and aromatic hydrocarbons according to claim 2, wherein the olefin content in said carbon four component is from 40 wt% to 80 wt%.

4. The process for producing ethylene, propylene and aromatic hydrocarbons according to any one of claims 1 to 3, wherein the catalytic cracking catalyst in the step (1) comprises an MFI structure molecular sieve, a Y-type molecular sieve, clay and a binder, and the MFI structure molecular sieve is contained in an amount of 5 to 60 wt%, preferably 10 to 50 wt%, the Y-type molecular sieve is contained in an amount of 1 to 40 wt%, preferably 1 to 30 wt%, the clay is contained in an amount of 10 to 70 wt%, preferably 15 to 45 wt%, and the binder is contained in an amount of 5 to 40 wt%, preferably 5 to 30 wt%, based on the total weight of the catalyst.

5. The process for producing ethylene, propylene and aromatic hydrocarbons according to any one of claims 1 to 3, wherein the catalytic cracking reactor is a reactor in which one or more of a riser reactor, a turbulent bed reactor and a fast bed reactor are combined; the operating conditions of the catalytic cracking reactor were: the average temperature is 550-700 ℃, the reaction pressure is 0.15-0.5 MPa, and the reaction space velocity is 2-600 h^-1。

6. A process for the production of ethylene, propylene and aromatic hydrocarbons according to any one of claims 1 to 3, characterised in that the aromatization catalyst comprises a molecular sieve, a metallic active component selected from one or more of the rare earth elements, elements of groups VIB, VIII, IIB, VIIB and a refractory inorganic oxide support, preferably silica and alumina.

7. The process for producing ethylene, propylene and aromatic hydrocarbons according to any one of claims 1 to 3, wherein the aromatization reactor is a fixed bed reactor.

8. The process for producing ethylene, propylene and aromatic hydrocarbons according to claim 7, wherein the aromatization reactor is operated under the following conditions: the reaction temperature is 350-450 DEG CThe reaction pressure is 0.20MPa to 2.0MPa, and the reaction space velocity is 0.2 to 2h^-1。

9. The process for producing ethylene, propylene and aromatic hydrocarbons according to any one of claims 1 to 3, wherein the steam cracking in the step (3) is carried out under the conditions of a reaction temperature of 780 to 850 ℃ and a residence time of 0.01 to 3 seconds.

10. The process for producing ethylene, propylene and aromatic hydrocarbons according to claim 9, wherein in the step (3), propane is fed into the propane steam cracking furnace to react, and ethane is fed into the ethane steam cracking furnace to react, thereby producing ethylene and propylene.

11. The process for producing ethylene, propylene and aromatic hydrocarbons according to any one of claims 1 to 3, wherein the dry gas and the liquefied gas in step (1) (2) are fed into the same gas separation apparatus to separate ethylene, ethane, propylene and propane, and the separation system employs a combination of a plurality of rectification columns.

12. A catalytic conversion system for producing ethylene, propylene and aromatic hydrocarbons, comprising a reaction unit, a catalyst, and a reactant stream; the reaction device comprises a catalytic cracking reactor, a regenerator, a first oil-gas separation system, an aromatization reactor, a second oil-gas separation system and a gas separation device which are sequentially communicated, wherein a regenerant outlet of the regenerator is communicated with the bottom of the catalytic cracking reactor, a settler and a gas-solid separation device are arranged at the upper part of the catalytic cracking reactor, a spent regenerant outlet of the gas-solid separation device is communicated with the regenerator, an oil-gas outlet of the gas-solid separation device is communicated with the first oil-gas separation system, a component C4 outlet of the first oil-gas separation system is communicated with the aromatization reactor, an outlet of the aromatization reactor is communicated with the second oil-gas separation system, and dry gas outlets of the first oil-gas separation system and the second oil-gas separation system are connected with the gas separation device; the catalytic cracking catalyst circularly flows in the catalytic cracking reactor and the regenerator, the aromatization catalyst is filled in the aromatization reactor, and light hydrocarbon raw materials are introduced through the raw material inlet and react in the reaction device.

Technical Field

The invention relates to a method and a system for producing chemical raw materials from petroleum raw materials, in particular to a method and a reaction system for producing ethylene, propylene and aromatic hydrocarbon from heavy oil.

Technical Field

Ethylene, propylene and BTX aromatics are growing in demand each year as a large group of basic chemical feedstocks. The catalytic cracking is used as a device for processing heavy oil to produce gasoline, and a large amount of propylene is also produced as a byproduct, so that the catalytic cracking is a main supplement source of the propylene market. Wherein, the deep catalytic cracking (such as DCC process) using more selective molecular sieve (ZSM-5) as an active center can produce propylene in large quantity and produce certain propylene and BTX aromatic hydrocarbon as byproducts. At present, wax oil or hydrogenated wax oil is generally adopted in the process, and a small amount of residual oil or paraffin-based atmospheric residual oil is mixed as a raw material.

The technology for preparing propylene from liquefied gas rich in olefin takes liquefied gas with lower added value as raw material, and the carbon tetraolefin in the liquefied gas is cracked under the action of catalyst to generate propylene and ethylene with high added value and aromatic hydrocarbon-rich gasoline component with high octane value, for example, in the DCC family technology, C4 olefin is returned to a catalytic cracking device for cyclic cracking to generate ethylene and propylene. Meanwhile, ethanol gasoline is popularized nationwide in 2020, so that etherified C4 or etherified light gasoline products are limited to be added into finished gasoline, a large number of C4 etherifying devices are idle, and reprocessing and utilization of C4 olefins are concerned.

CN104878A discloses a method for producing low-carbon olefin, which takes gasoline, kerosene, diesel oil, vacuum wax oil, residual oil and a mixture as raw materials, and takes a Y-shaped molecular sieve and a ZSM-5 molecular sieve as active centers; a fluidized bed or a moving bed reactor is adopted; the operating conditions are that the pressure is 150 kPa-300 kPa, the reaction temperature is 550 ℃ and 650 ℃, and the space velocity is 0.2-20hr^-1And the agent-oil ratio is 2-12. The method has high reaction temperature, more methane byproducts and large amount of unusable carbon four and diesel oil.

CN1056595A discloses a method for producing carbon olefin by using multi-stage feeding from ethane to residual oil as raw material. The method uses a molecular sieve containing alkaline earth metal as an active center; a riser reactor is adopted; the operation conditions are that the pressure is 130 kPa-400 kPa, the reaction temperature is 600-900 ℃, the residence time is 0.1-6 seconds and the catalyst-oil ratio is 5-100, and the multi-stage feeding cracking is carried out from high to low according to different cracking difficulties. Although the method solves the problem of byproducts such as carbon four, the method also has the problem of more byproducts such as methane and coke for raw materials with poor processing property,

CN1065963A discloses a method for producing low-carbon olefin by hydrocarbon oil multi-stage feeding, which takes gasoline, vacuum wax oil and residual oil as raw materials and takes a Y-shaped molecular sieve and a ZSM-5 molecular sieve as active centers; adopting a riser reactor and a fluidized bed reactor; the operating conditions are that the pressure is 130 kPa-400 kPa, the reaction temperature is 500-600 ℃, the riser residence time is 1-5 seconds, and the space velocity of the fluidized bed is 0.2-20hr^-1And the agent-oil ratio is 6-15, the atomized water vapor accounts for 1-60% of the weight of the raw material, wherein the mixture of the vacuum wax oil and the residual oil enters the bottom of the riser reactor,the gasoline component enters a fluidized bed reactor, and the riser reactor and the fluidized bed reactor are connected in series. The method can not solve the problem that the by-products of methane, carbon four and diesel oil are more.

CN102337148A discloses a method for producing low-carbon olefins by using gasoline rich in four to eight carbon atoms as a raw material. The method uses a Y-type molecular sieve and a ZSM-5 molecular sieve as active centers; adopting a riser reactor and a fluidized bed reactor; the operating conditions are that the pressure is 150 kPa-300 kPa, the reaction temperature is 480-^-1And the agent-oil ratio is 8-40. The method cannot solve the problem of accumulation of alkane components despite cyclic utilization of four-carbon to eight-carbon olefins.

CN101362961A discloses a method for producing low-carbon olefin and aromatic hydrocarbon by using hydrocarbons with the temperature of 160-270 ℃ as raw materials. The method uses a Y-type molecular sieve and a ZSM-5 molecular sieve as active centers; a riser reactor or a fluidized bed reactor is adopted; the operating conditions are that the pressure is 100 kPa-1000 kPa, the reaction temperature is 450 ℃ and 750 ℃, and the space velocity is 1-150hr^-1And the agent-oil ratio is 1-150. The method solves the problem of the export of part of diesel oil.

CN 1667089A discloses a method for producing low-carbon olefin by using gasoline, kerosene, diesel oil, vacuum wax oil, residual oil and mixture as raw materials. The method comprises the steps of firstly carrying out hydrotreating on a raw material and a circulating material flow, and then feeding the material flows into a catalytic cracking reactor. Wherein the gas recycle is ethane, propane and C4. The liquid circulation feed is C5-C6, heavy gasoline aromatic raffinate oil, LCO, HCO and oil slurry. Although the method solves the problem of the output of most by-products, the method cannot solve the problem of the accumulation of alkane components and polycyclic aromatic hydrocarbon components.

The method has the problems of high carbon four-component cycle ratio, low propylene yield and high energy consumption.

Disclosure of Invention

The invention aims to solve the technical problems of high cycle ratio of the four carbon components, low propylene yield and high energy consumption in the prior art, and provides a method for producing ethylene, propylene and aromatic hydrocarbon with high product yield.

The second technical problem to be solved by the invention is to provide a catalytic conversion reaction system for producing ethylene, propylene and aromatic hydrocarbon.

The invention provides a method for producing ethylene, propylene and aromatic hydrocarbon, which comprises the following steps:

(1) introducing the four carbon components into a catalytic cracking reactor, carrying out contact reaction with a regenerated catalytic cracking catalyst from a regenerator, allowing an oil gas and catalyst mixture obtained by the reaction to enter a settler for gas-solid separation, separating the separated reaction oil gas into dry gas, liquefied gas and gasoline through a first oil-gas separation system, and further separating propylene, propane and four carbon components from the liquefied gas;

(2) the separated four carbon components enter an aromatization reactor to contact and react with an aromatization catalyst, and dry gas, liquefied gas and gasoline rich in aromatic hydrocarbon are separated from reaction products through a separation system, so that ethylene, ethane, propylene, propane and aromatic hydrocarbon products are further separated;

(3) and (3) in the step (1) and the step (2), the propane and the ethane enter a steam cracking furnace for steam cracking to generate ethylene and propylene.

A catalytic conversion system for producing ethylene, propylene and aromatic hydrocarbons, comprising a reaction unit, a catalyst, and a reactant stream; the reaction device comprises a catalytic cracking reactor, a regenerator, a first oil-gas separation system, an aromatization reactor, a second oil-gas separation system and a gas separation device which are sequentially communicated, wherein a regenerant outlet of the regenerator is communicated with the bottom of the catalytic cracking reactor, a settler and a gas-solid separation device are arranged at the upper part of the catalytic cracking reactor, a spent regenerant outlet of the gas-solid separation device is communicated with the regenerator, an oil-gas outlet of the gas-solid separation device is communicated with the first oil-gas separation system, a component C4 outlet of the first oil-gas separation system is communicated with the aromatization reactor, an outlet of the aromatization reactor is communicated with the second oil-gas separation system, and dry gas and liquefied gas outlets of the second oil-gas separation system are connected with the gas separation device; the catalytic cracking catalyst circularly flows in the catalytic cracking reactor and the regenerator, the aromatization catalyst is filled in the aromatization reactor, and light hydrocarbon raw materials are introduced through the raw material inlet and react in the reaction device.

The method for producing ethylene, propylene and aromatic hydrocarbon and the catalytic conversion reaction system provided by the invention have the beneficial effects that:

in the prior art method for producing low-carbon olefins by further catalytically cracking carbon four components in a catalytic cracking reactor, the reaction speed of the tetracarbon is obviously slower than that of the tetracarbon, so that the conversion rate of the tetracarbon is higher and the conversion rate of the tetracarbon is extremely low in the reaction process. In the prior art, four carbon components obtained from catalytic cracking products are recycled to a catalytic cracking reactor, so that the carbon tetralkyl hydrocarbon in a recycle stream is continuously accumulated. If the carbon four cycle ratio is not increased, the propylene yield is reduced due to the decrease in the olefin content in carbon four. If the carbon four cycle ratio is increased, the energy consumption is greatly increased.

According to the method for producing ethylene, propylene and aromatic hydrocarbon, the problem of accumulation of the carbon tetrane in the carbon four-component circulating flow is solved by aromatizing the carbon four components, and the energy consumption and the operation cost in the carbon four-component catalytic cracking are greatly reduced. Meanwhile, the yield of ethylene, propylene and aromatic hydrocarbon is greatly increased. The method for producing the ethylene, the propylene and the aromatic hydrocarbon can also reduce the heat load of an aromatization device and reduce the energy consumption of the aromatization device. The method for producing the ethylene, the propylene and the aromatic hydrocarbon can provide more high-quality cracking raw materials of the ethane and the propane for steam cracking, thereby greatly increasing the yield of the ethylene and the propylene.

Drawings

FIG. 1 is a schematic flow diagram of a process for producing ethylene, propylene and aromatic hydrocarbons according to the present invention.

FIG. 2 is a schematic flow chart of a process for producing ethylene and propylene from the heavy oil in comparative examples 1 and 2.

Wherein:

1-a catalytic cracking reactor; 2-an aromatization reactor; 4-a regenerator; 5-a first oil-gas separation system; 6-a second oil-gas separation system; 8-regenerated catalyst inclined tube; 9-spent catalyst inclined tube; 10-a stripping section; 11-a settler; a 32-propane cracking furnace; a 33-ethane cracking furnace; 35-a gas separation device; 31. 34-dry gas line, 37-ethane line; 7-feed line; 12. 14, 18, 19, 20, 21, 22, 23, 29, 30-lines.

Detailed Description

The following specifically describes embodiments of the present invention:

the invention provides a method for producing ethylene, propylene and aromatic hydrocarbon, which comprises the following steps:

(1) introducing the four carbon components into a catalytic cracking reactor, carrying out contact reaction with a regenerated catalytic cracking catalyst from a regenerator, allowing an oil gas and catalyst mixture obtained by the reaction to enter a settler for gas-solid separation, separating the separated reaction oil gas into dry gas, liquefied gas and gasoline through a separation system, and further separating ethylene, ethane, propylene, propane and four carbon components from the liquefied gas;

(2) the separated four carbon components enter an aromatization reactor to contact and react with an aromatization catalyst, and dry gas, liquefied gas and gasoline rich in aromatic hydrocarbon are separated from reaction products through a separation system, so that ethylene, ethane, propylene, propane and aromatic hydrocarbon products are further separated;

(3) and (3) in the step (1) and the step (2), the propane and the ethane enter a steam cracking furnace for steam cracking to generate ethylene and propylene.

In the method provided by the invention, the four-carbon component comes from a catalytic cracking unit and contains C4 olefin and C4 alkane, wherein the content of the olefin is more than 20 wt%. Preferably, the olefin content in the carbon four-component is 40 wt% to 80 wt%.

In the method provided by the invention, the catalytic cracking catalyst in the step (1) contains an MFI structure molecular sieve, a Y-type molecular sieve, clay and a binder, wherein based on the total weight of the catalyst, the content of the MFI structure molecular sieve is 5-60 wt%, preferably 10-50 wt%, the content of the Y-type molecular sieve is 1-40 wt%, preferably 1-30 wt%, the content of the clay is 10-70 wt%, preferably 15-45 wt%, and the content of the binder is 5-40 wt%, preferably 5-30 wt%.

In the method provided by the invention, the catalytic cracking reactor is one or a combination of more of a riser reactor, a turbulent bed reactor and a fast bed reactorThe reactor of (4); the operating conditions of the catalytic cracking reactor were: the average temperature is 550-700 ℃, the reaction pressure is 0.15-0.5 MPa, and the reaction space velocity is 2-600 h^-1

In the method provided by the invention, the gas-solid separation in the step (1) is carried out in a settler, a cyclone gas-solid separator is adopted to separate the catalyst and the reaction oil gas, and the separated catalyst is subjected to steam stripping in a steam stripper.

In the method provided by the invention, the aromatization reactor is a fixed bed reactor.

In the method provided by the invention, the aromatization catalyst contains a molecular sieve, a metal active component and a heat-resistant inorganic oxide carrier, wherein the metal active component is selected from one or more of rare earth elements, VIB, VIII, IIB and VIIB group elements, and the heat-resistant inorganic oxide is preferably silicon oxide and aluminum oxide.

In the method provided by the invention, the operation conditions of the aromatization reactor are as follows: the reaction temperature is 350-450 ℃, the reaction pressure is 0.20-2.0 MPa, and the reaction space velocity is 0.2-2 h^-1。

In the method provided by the invention, in the step (3), propane enters a propane steam cracking furnace for reaction, and ethane enters an ethane steam cracking furnace for reaction to generate ethylene and propylene.

The steam cracking in the step (3) is carried out under the operating conditions that the reaction temperature is 780-850 ℃ and the retention time is 0.01-3 seconds.

In the method provided by the invention, preferably, in the step (1) and (2), the dry gas enters the same gas separation device to separate ethylene, ethane, propylene and propane, and the gas separation device adopts a combination of a plurality of rectifying towers. The separation system comprises a fractionating tower, an absorption stabilizing system and a gas separation device. Specifically, the separated reaction oil gas enters a catalytic cracking fractionating tower, and the middle part of the fractionating tower is pumped with product gasoline. Gasoline and rich gas obtained from the top of the fractionating tower enter an absorption stabilizing system, product gasoline, dry gas and liquefied gas separated by the stabilizing system enter a gas separating device, and four components of propylene, propane and carbon are separated from the liquefied gas. The dry gas enters a split separation device to separate ethylene, ethane and other gases.

The aromatic hydrocarbon obtained in the step (2) is C6-C10 monocyclic aromatic hydrocarbon.

In the method provided by the invention, the C4 component from the catalytic cracking fractionating tower is a C4 component produced by a catalytic cracking unit, the catalytic cracking unit contacts a heavy oil raw material with a catalytic cracking catalyst, and the heavy oil raw material is subjected to cracking reaction under the catalytic cracking condition to obtain dry gas, liquefied gas, gasoline, diesel oil and oil slurry, wherein the liquefied gas is further separated to obtain a C4 component. The heavy oil raw material is selected from one or a mixture of several of wax oil and atmospheric residue vacuum residue, or other organic compounds or hydrocarbons with carbon number more than 16. The catalytic cracking catalyst comprises an MFI structure molecular sieve, a Y-type molecular sieve, clay and a binder, wherein based on the total weight of the catalyst, the MFI structure molecular sieve accounts for 5-60 wt%, preferably 10-50 wt%, the Y-type molecular sieve accounts for 1-40 wt%, preferably 1-30 wt%, the clay accounts for 10-70 wt%, preferably 15-45 wt%, and the binder accounts for 5-40 wt%, preferably 5-35 wt%.

The operation conditions of the reactor in the catalytic cracking device are as follows: the average temperature is 500-700 ℃, the reaction pressure is 0.15-0.5 MPa, and the reaction space velocity is 2-600 h^-1。

A catalytic conversion system for producing ethylene, propylene and aromatics comprising a reaction unit, a catalyst, and a reactant stream; the reaction device comprises a catalytic cracking reactor, a regenerator, a first oil-gas separation system, an aromatization reactor, a second oil-gas separation system and a gas separation device which are sequentially communicated, wherein a regenerant outlet of the regenerator is communicated with the bottom of the catalytic cracking reactor, a settler and a gas-solid separation device are arranged at the upper part of the catalytic cracking reactor, a spent regenerant outlet of the gas-solid separation device is communicated with the regenerator, an oil-gas outlet of the gas-solid separation device is communicated with the first oil-gas separation system, a component C4 outlet of the first oil-gas separation system is communicated with the aromatization reactor, an outlet of the aromatization reactor is communicated with the second oil-gas separation system, and a dry gas outlet and a liquefied gas outlet of the second oil-gas separation system are connected with the gas separation device; the catalytic cracking catalyst circularly flows in the catalytic cracking reactor and the regenerator, the aromatization catalyst is filled in the aromatization reactor, and light hydrocarbon raw materials, preferably four components of carbon, are introduced through a raw material inlet and react in a reaction device.

In the catalytic conversion system provided by the invention, the catalytic cracking reactor is selected from one or a combination of a riser reactor, a turbulent bed reactor and a fast bed reactor; preferably a riser reactor, and the aromatization reactor is a fixed bed reactor.

The regenerator is a regenerator of various forms in the art that uses air or air mixed oxygen-rich gas to react with coke on the spent catalyst, burns off the coke on the spent catalyst to restore the activity of the spent catalyst, called regenerated catalyst, and raises the catalyst temperature to 600 ℃ to 760 ℃ in order to return to the reactor to bring heat and catalytic media to the reaction.

In the method and the system provided by the invention, the products of the catalytic cracking reactor and the aromatization reactor are separated by adopting an oil-gas separation system, and the oil-gas separation system can adopt one or more of a fractionating tower, a rectifying tower, an absorption tower and a desorption tower.

The method is described below with reference to the accompanying drawings, but the invention is not limited thereto.

FIG. 1 is a schematic flow diagram of a process for producing ethylene, propylene and aromatic hydrocarbons according to the present invention, as shown in FIG. 1: the method comprises the following steps that four components of raw carbon enter a catalytic cracking reactor 1 after being preheated through a pipeline 7 to be in contact reaction with a hot regenerated catalyst from a regenerator 4 through a regenerated catalyst inclined pipe 8, the catalytic cracking reactor 1 is a riser reactor, oil gas and the catalyst after reaction enter a settler 11, a gas-solid separation device is arranged in the settler 11, the oil gas and the catalyst are separated in the settler 11, a separated spent catalyst with carbon enters a stripping section 10 for stripping, the separated spent catalyst enters the regenerator 4 through a spent catalyst inclined pipe 9, coke on the spent catalyst is burnt by air from a pipeline 25 in the regenerator 4 to restore activity, and the air enters the bottom of the catalytic cracking reactor 1 through the regenerated catalyst inclined pipe 8 to be recycled; the separated oil and gas enters the first oil and gas separation system 5 through a pipeline 12. The first oil-gas separation system 5 leads out gasoline through a pipeline 15, diesel oil through a pipeline 16, oil slurry through a pipeline 26, propylene through a pipeline 27 and propane through a pipeline 13 and enters a propane cracking furnace 32; the dry gas enters a gas separation device 35 through a pipeline 31, the gas separation device 35 consists of a plurality of rectifying towers, H2-CH4 is led out through a pipeline 28 after being separated by the rectifying towers, ethylene is led out through a pipeline 36, and ethane is led out through a pipeline 37 and enters an ethane cracking furnace 33; a second carbon four component is withdrawn via line 14 and a portion of the second carbon four component is recycled via line 28 back to the catalytic cracking reactor 1.

The other part of the second carbon four-component enters an aromatization reactor 2 through a pipeline 14, wherein the aromatization reactor is a fixed bed reactor. In the aromatization reactor, the second carbon four-component and aromatization catalyst are contacted and reacted, the reaction product is fed into second oil-gas separation system 6 by means of pipeline 17, after separation, the obtained gasoline rich in aromatic hydrocarbon is led out by means of pipeline 21, propylene is led out by means of pipeline 18, propane is led out by means of pipeline 19 and fed into propane cracking furnace 32, the dry gas is led out by means of pipeline 34 and fed into gas separation device 35, and the separated carbon four-component is led out by means of pipeline 20.

The effects of the method for producing ethylene, propylene and aromatic hydrocarbons according to the present invention will be illustrated below by examples and comparative examples, but the present invention is not limited thereto.

Comparative example and example, a C4 component as a raw material was used in a catalytic cracking separation column from Shijiazhuang, a division of petrochemical Co., Ltd., China, and the properties thereof are shown in Table 1. The catalytic cracking catalyst used was DMMC-1 catalyst produced by catalyst division of petrochemical Co., Ltd, China, and its properties are shown in Table 2. The aromatization catalyst used is sold under the trademark DLP-XA and is produced by Shandong Daqi chemical technology Co.

Comparative examples 1 to 2

Comparative examples 1-2 adopt the process for producing ethylene and propylene by C4 recycle catalytic cracking as shown in figure 2, raw material carbon four components enter a catalytic cracking riser reactor through a line 7 after being preheated to contact with a thermal regeneration catalytic catalyst from a regenerator 4 through a regeneration catalyst inclined tube 8 for catalytic cracking reaction, the generated oil gas and catalyst flow upwards to enter a settler 11, a gas-solid separation device is arranged in the settler 11, the reaction oil gas and catalyst are separated in the settler 11, the separated spent catalyst with carbon enters the regenerator 4 through a spent catalyst inclined tube 9 after being stripped by a stripping section 10, coke on the spent catalyst is burnt by air from a line 25 in the regenerator 4 to restore the activity, and then the air enters the bottom of the riser reactor through the spent catalyst inclined tube 8 to circularly participate in the reaction. The separated oil and gas enters the first oil and gas separation system 5 through a pipeline 12. The first oil-gas separation system consists of a fractionating tower, a rectifying tower, an absorption tower and a desorption tower, gasoline obtained after separation is led out through a pipeline 15, diesel oil is led out through a pipeline 16, oil slurry is led out through a pipeline 26, propylene is led out through a pipeline 27, and propane is led out through a pipeline 13 and enters a propane cracking furnace 32 to generate propylene 23 and ethylene 22. The resulting dry gas is withdrawn via line 31 and passed to a gas separation unit 35, separated ethylene 28, other gases 36 and ethane 37, which is withdrawn via line 37 and passed to an ethane cracking furnace 33 to produce ethylene and propylene. The four carbon components are withdrawn via line 14, a portion of the four carbon components are returned to the catalytic cracking reactor via line 28, and the remaining four carbon components are withdrawn from the unit via line 20 as product.

The reaction conditions of comparative examples 1-2 are shown in Table 3, and the product yields are shown in Table 4.

Examples 1 to 2

The embodiment 1-2 adopts a reaction flow shown in the attached figure 1, specifically, (1) four components of raw material carbon are introduced into a catalytic cracking reactor and contact with a regenerated catalyst from a regenerator for reaction, an oil gas and catalyst mixture obtained by the reaction enters a settler for gas-solid separation, and dry gas, liquefied gas and gasoline are separated from separated reaction oil gas through a first oil-gas separation system, and ethylene, propylene, aromatic hydrocarbon products and four components of carbon are further separated; (2) the separated four carbon components enter an aromatization reactor to contact and react with an aromatization catalyst, and dry gas, liquefied gas and gasoline rich in aromatic hydrocarbon are separated from reaction products through a second oil-gas separation system, so that ethylene, propylene and aromatic hydrocarbon products are further separated; (3) and (2) separating the dry gas and the liquefied gas in the step (1) and (2) to obtain ethane and propane, and introducing the ethane and the propane into an ethane-propane steam cracking furnace and a propane steam cracking furnace for steam cracking to generate ethylene and propylene.

The reaction conditions of examples 1-2 are shown in Table 3, and the product yields are shown in Table 4.

As can be seen from table 4, the carbon four cycle ratios (carbon four feed/feed) of the examples starting with C4 component a and C4 component B were reduced by 0.2 and 0.3, respectively, ethylene by 0.36 and 1.05 percentage points, propylene by 1.10 and 1.70 percentage points, and aromatic hydrocarbon (BTX) by 7.86 and 16.38 percentage points, respectively, compared to the comparative examples.

TABLE 1 raw materials carbon four Components

Raw materials	Carbon four component A	Carbon four component B
			Isobutane	26.18	38.75
N-butane	6.35	9.97
			Butene-1	10.01	11.18
Isobutene	28.90	12.92
			Cis-butenediol	16.52	14.06
Butene of trans-butene	12.03	13.12

TABLE 2 catalytic cracking catalyst composition and Properties

RE2O3	0.56
		Al2O3	54
Physical Properties
		Specific surface area, m2/g	100
Pore volume, cm3/g	0.176
		Micropore volume, cm3/g	0.026
Apparent density, g/cm3	0.91
		Sieving, according to
0-20μm	0.8
		0-40μm	10.4
0-80μm	70.8
		0-110μm	88.5
0-149μm	97.8
		>149μm	2.2
APS,μm	64.3
		Slightly antagonistic activity, w% (520 ℃ C.)	55

TABLE 3

Item	Comparative example 1	Example 1	Comparative example 2	Example 2
					Catalytic cracking reactor
C4 raw material	Carbon four component A	Carbon four component A	Carbon four component B	Carbon four component B
					Reaction pressure/MPa	0.2	0.2	0.28	0.28
Reaction temperature/. degree.C	620	620	650	650
					Regenerator temperature/. degree.C	690	690	710	710
Ratio of agent to oil	15	15	20	20
					Reaction space velocity/h-1	10	10	50	50
Atomized steam/%)	25	25	15	15
					Carbon to four cycle ratio	0.5	0.2	0.4	0.2
Aromatization reactor
					Reaction pressure/MPa	/	1.1	/	1.3
Reaction temperature/. degree.C	/	380	/	420
					Reaction space velocity/h-1	/	1.0	/	1.3
Ethane steam cracking furnace
					Temperature/. degree.C	/	830	/	830
pressure/MPa	/	0.13	/	0.13
					Atomized steam/%)	/	60	/	60
Propane steam cracking furnace
					Temperature/. degree.C	/	815	/	815
pressure/MPa	/	0.13	/	0.13
					Atomized steam/%)	/	60	/	60

TABLE 4

Example numbering	Comparative example 1	Example 1	Comparative example 2	Example 2
					Product yield
H2-C2	5.77	7.99	7.94	8.74
					C3-C4	76.38	59.67	86.26	75.01
C5+ gasoline	13.51	27.03	3.04	13.19
					Diesel oil	0.77	1.20	0.42	0.68
Oil slurry	0.02	0.25	0.12	0.26
					Coke	3.36	3.58	2.02	2.11
Wherein:
					ethylene	3.47	4.52	3.99	4.35
Propylene (PA)	16.59	17.69	8.58	10.28
					BTX	1.26	17.64	1.34	9.20