CN112723969B

CN112723969B - Method for producing ethylene, propylene and aromatic hydrocarbon and catalytic conversion device

Info

Publication number: CN112723969B
Application number: CN201910974659.XA
Authority: CN
Inventors: 张执刚; 魏晓丽; 龚剑洪; 张策; 崔琰; 刘宪龙
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2019-10-14
Filing date: 2019-10-14
Publication date: 2023-06-09
Anticipated expiration: 2039-10-14
Also published as: CN112723969A

Abstract

A process for preparing ethylene, propylene and aromatic hydrocarbon includes such steps as contacting heavy oil with the first catalyst from regenerator in the first reactor to generate oil-gas and catalyst mixture, contacting the separated part of four carbon components with the regenerated catalyst from regenerator in the second reactor to generate oil-gas and catalyst mixture, loading the rest of four carbon components in aromatization reactor, and separating out dry gas, liquefied gas and gasoline rich in aromatic hydrocarbon from the reaction product of aromatization reactor. The method and the device provided by the invention solve the problem of accumulating the alkane of the four carbon cycles, can greatly increase the yields of ethylene, propylene and arene, and simultaneously greatly reduce the energy consumption and the operation cost of the four carbon cycles.

Description

Method for producing ethylene, propylene and aromatic hydrocarbon and catalytic conversion device

Technical Field

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

Technical Field

Ethylene, propylene and BTX aromatics are growing in demand annually as a large number of basic chemical feedstocks. Catalytic cracking, which is used as a device for producing gasoline by processing heavy oil, also produces a large amount of propylene as a byproduct, and is a main supplementary source in the propylene market. Wherein deep catalytic cracking (such as DCC process) using more shape selective molecular sieve (ZSM-5) as active center can produce propylene in large quantity and by-produce certain propylene and BTX aromatic hydrocarbon. 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 doped as a raw material.

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

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

CN1034586a discloses a method for producing low-carbon olefin from hydrocarbon oil, which uses gasoline, kerosene, diesel oil, vacuum wax oil, residual oil and mixture as raw materials, and uses Y-type molecular sieve and phosphorus-containing ZSM-5 molecular sieve as active centers; a fluidized bed or riser reactor is adopted; the operation conditions are that the pressure is 120 kPa-400 kPa, the reaction temperature is 480-680 ℃, the residence time is 0.1-6 seconds, the catalyst-to-oil ratio is 4-20, and the atomized water vapor accounts for 1-50% of the weight of the raw material. The method has similar problems as CN104878 in that the reaction temperature is high, methane byproducts are more, and a large amount of unusable carbon four and diesel oil are produced despite the modification of the catalyst.

CN1056595a discloses a process for low-carbon olefin production using multistage feed from ethane to resid as feedstock. The method uses an alkaline earth metal-containing molecular sieve as an active center; a riser reactor is adopted; the operation conditions are 130kPa to 400kPa of pressure, 600 ℃ to 900 ℃ of reaction temperature, 0.1 to 6 seconds of residence time and 5 to 100 of catalyst-oil ratio, and the cracking of the multi-stage feed is carried out from high to low according to different cracking difficulties. Although the method solves the problems of byproducts such as carbon four, the method also has the problems of more methane and coke byproducts for the raw materials with poor processing property,

CN1065963a discloses a method for producing low-carbon olefin by multi-stage feeding of hydrocarbon oil, which uses gasoline, vacuum wax oil and residual oil as raw materials and uses a Y-type molecular sieve and a ZSM-5 molecular sieve as active centers; a riser reactor and a fluidized bed reactor are adopted; the operation conditions are that the pressure is 130 kPa-400 kPa, the reaction temperature is 500-600 ℃, the retention time of the riser is 1-5 seconds, and the space velocity of the fluidized bed is 0.2-20hr ^-1 And the agent-oil ratio is 6-15, the atomized water vapor accounts for 1% -60% of the weight of the raw materials, wherein the mixture of the vacuum wax oil and the residual oil enters the bottom of the riser reactor, the gasoline component enters the fluidized bed reactor, and the riser reactor and the fluidized bed reactor are connected in series. The method can not solve the problem of more methane, carbon four and diesel byproducts.

CN102337148A discloses a method for producing low-carbon olefin by using gasoline rich in four to eight carbon atoms as raw material. The method uses Y-type molecular sieve and ZSM-5 molecular sieve as active centers; a riser reactor and a fluidized bed reactor are adopted; the operation conditions are that the pressure is 150 kPa-300 kPa, the reaction temperature is 480-680 ℃, the retention time of the riser is 1-5 seconds, and the space velocity of the fluidized bed is 0.2-30hr ^-1 The agent-oil ratio is 8-40. The method can not solve the accumulation of alkane components despite the cyclic utilization of the C four-to C eight-alkene.

CN101362961a discloses a process for producing low-carbon olefines and aromatic hydrocarbons by using hydrocarbons at 160-270 deg.c as raw material. The method uses Y-type molecular sieve and ZSM-5 molecular sieve as active centers; a riser reactor or a fluidized bed reactor is adopted; the operation conditions are that the pressure is 100 kPa-1000 kPa, the reaction temperature is 450-750 ℃, and the airspeed is 1-150hr ^-1 Ratio of agent to oil of 1-150. The method solves the problem of partial diesel oil outlet.

CN101747928A discloses a method for producing low-carbon olefin and aromatic hydrocarbon by using vacuum wax oil and residual oil as raw materials. The method uses Y-type molecular sieve and ZSM-5 molecular sieve as active centers; a riser reactor or a fluidized bed reactor is adopted; the feed reactor and the product recycle reactor for C4 olefins at-250℃ share a regenerator. The method solves the problem of partial diesel oil outlet, but cannot solve the problem of accumulation of alkane components and polycyclic aromatic hydrocarbon components.

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 hydrotreating 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 carbon four. The liquid circulation feed is C5-C6, heavy gasoline aromatic raffinate oil, LCO, HCO and slurry oil. Although the method solves the outlet of most byproducts, the method can not solve the accumulation problem of alkane components and polycyclic aromatic hydrocarbon components.

CN101747928A discloses a method for producing low-carbon olefin and aromatic hydrocarbon by using vacuum wax oil and residual oil as raw materials. The method combines catalytic cracking and steam cracking. The method comprises the steps of separating alkane from c2 to gasoline from a catalytic cracking product, feeding the alkane into a steam cracking reactor, and returning butene, recycle oil and slurry oil into the catalytic cracking reactor. Aromatic hydrocarbons are produced by an aromatic hydrocarbon extraction process. The method solves the problem of accumulation of alkane components and polycyclic aromatic hydrocarbon components. But the separation of the alkene and alkane of each component above C4 has high energy consumption and is not reimbursed.

In the method, the reaction speed of the carbon tetraalkyl alkane is obviously slower than that of the carbon tetraalkyl alkane, so that the conversion rate of the carbon tetraalkyl alkane is higher in the process of mixing the carbon tetraalkyl alkane in the riser reactor, and the conversion rate of the carbon tetraalkyl alkane is extremely low. In the cyclic reaction process of the four-carbon components in the prior art, unreacted four-carbon alkane is reserved in the four-carbon components, and alkane generated by raw oil is accumulated in a circulating material flow continuously. The problem is that if the carbon four recycle ratio is not increased, the propylene yield is lowered due to the decrease in the olefin content in the carbon four. If the carbon four-cycle proportion is increased, the energy consumption is greatly increased.

Disclosure of Invention

One of the technical problems to be solved by the invention is to solve the problems in the process of preparing the low-carbon olefin from the hydrocarbon oil in the prior art, and provides a method for producing ethylene, propylene and aromatic hydrocarbon from heavy oil with high product yield by reducing the accumulation of alkane components.

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

The method for producing ethylene, propylene and aromatic hydrocarbon provided by the invention comprises the following steps:

(1) The heavy oil raw material enters a first reactor to be in contact reaction with a first strand of regenerated catalyst from a regenerator, the oil gas and catalyst mixture obtained by the reaction is subjected to gas-solid separation, and the separated spent catalyst is burnt and regenerated in the regenerator and is heated; the separated reaction oil gas is separated into dry gas, liquefied gas, gasoline, diesel oil and slurry oil by a first separation system, and ethylene, propylene, aromatic hydrocarbon products and four carbon components are further separated;

(2) Introducing a part of the carbon four components into a second reactor singly or together with external carbon four components, carrying out contact reaction with a second strand of regenerated catalyst from a regenerator, and allowing the oil gas and catalyst mixture obtained by the reaction to enter a settler of a first reactor for gas-solid separation;

(3) The rest of the four carbon components enter an aromatization reactor to contact and react with an aromatization catalyst, and the reaction product is separated into dry gas, liquefied gas and gasoline rich in aromatic hydrocarbon by a second separation system to further separate ethylene, propylene and aromatic hydrocarbon products.

The catalytic conversion device for producing ethylene, propylene and aromatic hydrocarbon provided by the invention is used for the catalytic cracking method for producing ethylene, propylene and aromatic hydrocarbon, and comprises the following steps: the device comprises a first reactor, a second reactor, gas-solid separation equipment, a regenerator, a first oil-gas separation system, an aromatization reactor and a second oil-gas separation system; the regeneration agent outlet of the regenerator is communicated with the bottoms of the first reactor and the second reactor, the first reactor and the second reactor share one set of gas-solid separation equipment, the spent agent outlet of the gas-solid separation equipment is communicated with the regenerator, the oil-gas outlet of the gas-solid separation equipment is communicated with the first separation system, the C4 outlet of the first separation system is respectively communicated with the second reactor and the aromatization reactor, and the outlet of the aromatization reactor is communicated with the second separation system.

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

the method is used for producing ethylene, propylene and aromatic hydrocarbon by taking heavy oil as a raw material, and can produce the ethylene, the propylene and the aromatic hydrocarbon in the maximum quantity. The method solves the problem of accumulating alkane of four carbon cycles, greatly increases ethylene, propylene and arene, and greatly reduces the energy consumption and the operation cost of four carbon cycles; the method reduces the coke yield of the catalytic cracking device required by meeting the heat balance; the method can also reduce the heat-taking load of the aromatization device and reduce the energy consumption of the aromatization device; the method can utilize heavy oil to provide more high-quality cracking raw materials of ethane, propane and n-butane for steam cracking, thereby greatly increasing the yield of ethylene and propylene.

Drawings

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

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

Wherein:

202-a first reactor; 206-a regenerator; 210-a second reactor; 222-stripper; 224-settler; 226-a fractionation column; 230-a post light hydrocarbon separation system; 233-gas separation device; 237-aromatization reactor; the balance being the pipeline.

Detailed Description

The following describes specific embodiments of the present invention:

a process for producing ethylene, propylene and aromatics comprising:

In the method provided by the invention, the heavy oil raw material is selected from one or a mixture of more than 16 organic compounds of wax oil, atmospheric residuum, vacuum residuum and carbon number.

In the method provided by the invention, the catalyst in the step (1) and the step (2) is a catalytic cracking catalyst, and comprises an MFI structure molecular sieve, a Y-type molecular sieve, clay and a binder, wherein 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 5-35 wt%, based on the total weight of the catalyst.

Preferably, the extraneous carbon four component is a carbon four component having an olefin content greater than 20%.

In the method provided by the invention, the first reactor is one or a combination of a riser reactor, a turbulent bed reactor and a rapid bed reactor; the operating conditions of the first reactor were: 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

The invention providesIn the method, the second reactor is one or a combination of a riser reactor, a turbulent bed reactor and a rapid bed reactor; the operating conditions of the 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 process provided by the invention, the carbon four component separated in step (1) contains C4 olefins and C4 paraffins, and typically has an olefin content of greater than 20wt%, preferably an olefin content of 40 to 90wt%.

In the method provided by the invention, the operating 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, 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 and VIB, VIII, IIB, VIIB elements, and the heat-resistant inorganic oxide is preferably silicon oxide and aluminum oxide.

In the method provided by the invention, the gas-solid separation in the step (1) and the step (2) is carried out in a settler, a cyclone gas-solid separator is adopted to separate the catalyst and the reaction oil gas, the separated catalyst is stripped in a stripper, and the oil gas adsorbed on the catalyst is removed.

In the method provided by the invention, the arene obtained in the step (3) is C6-C10 monocyclic arene.

A catalytic conversion device for producing ethylene, propylene and aromatic hydrocarbon, which is used for the catalytic cracking method for producing ethylene, propylene and aromatic hydrocarbon, and comprises the following steps: the device comprises a first reactor, a second reactor, gas-solid separation equipment, a regenerator, a first oil-gas separation system, an aromatization reactor and a second oil-gas separation system; the regeneration agent outlet of the regenerator is communicated with the bottoms of the first reactor and the second reactor, the first reactor and the second reactor share one set of gas-solid separation equipment, the spent agent outlet of the gas-solid separation equipment is communicated with the regenerator, the oil-gas outlet of the gas-solid separation equipment is communicated with the first separation system, the C4 outlet of the first separation system is respectively communicated with the second reactor and the aromatization reactor, and the outlet of the aromatization reactor is communicated with the second separation system.

In the catalytic conversion device for producing ethylene, propylene and aromatic hydrocarbon, the first reactor and the second reactor are one or a combination of a riser reactor, a turbulent bed reactor and a rapid bed reactor, and the aromatization reactor is a fixed bed reactor.

The regenerator is a form of regenerator in the art that uses air or an air-mixed oxygen-enriched gas to react with coke on the spent catalyst, burns the coke off the spent catalyst to restore the activity of the spent catalyst (referred to as 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 device provided by the invention, the first reactor and the second reactor share one set of settler and stripper. The first separation system and the second separation system can adopt one or more of a fractionating tower, a rectifying tower, an absorbing tower and a desorber.

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

FIG. 1 is a schematic flow chart of the method provided by the invention, as shown in FIG. 1, heavy oil raw oil is preheated and then enters a first reactor 202 through a pipeline 201 to contact and react with regenerated catalyst heated by a regenerator 206 through a regenerated catalyst inclined pipe 209, the first reactor is a riser reactor, generated oil gas and catalyst enter a settler 224, the oil gas and the catalyst in the settler 224 are separated, the separated regenerated catalyst with carbon enters a stripping section 222 to be stripped, enters the regenerator 206 through the regenerated catalyst inclined pipe 223, the air in the regenerator 206 through a pipeline 301 burns coke on the regenerated catalyst to restore activity, and then enters the bottom of the first reactor 202 through the regenerated catalyst inclined pipe 209 to be recycled; the separated oil and gas enters fractionation column 226 via line 225. Product diesel 227 is withdrawn from the middle of the fractionation column 226. Product slurry 228 is withdrawn from the bottom. The following products of gasoline obtained from the top of the fractionating tower 226 enter a rear light hydrocarbon separation system 230 through a pipeline 229 to separate product gasoline 304, dry gas 231 and liquefied gas 232, and the liquefied gas 232 enters a gas separation device 233 to separate propylene 234, propane 235 and four carbon components 236.

A portion of the carbon four component 236 enters the second reactor 210 via line 221 and contacts the regenerated catalyst heated from the regenerator 206 via the regenerator diagonal 200, the resulting oil and gas and catalyst enter a settler 224 where the oil and gas and catalyst are separated and the separated char-bearing catalyst is burned via stripping section 222 from line 223 into the regenerator 206. The air from line 301 in regenerator 206 burns off the catalyst to restore activity and then enters the bottom loop of reactor 210 via line 200 to participate in the reaction, and the separated oil and gas enter fractionation column 226 via line 204.

The remaining four carbon components enter the four carbon aromatization unit 237 via line 240. The product is separated to obtain gasoline 239 rich in aromatic hydrocarbon, dry gas 305 and liquefied gas 238.

The dry gas 231 and the dry gas 305 separate ethylene and ethane, as well as other gases.

The effect of the method for producing ethylene, propylene and aromatic hydrocarbon from heavy oil provided by the present invention is described below by way of examples and comparative examples, but the present invention is not limited thereto.

In the comparative examples and examples, heavy oil feedstock A was used as a hydrogenated residue, obtained from a petroleum refinery, shijia, china petrochemical Co., ltd; the heavy oil raw material B is straight run wax oil, and is obtained from Yanshan division of China petrochemical industry Co., ltd. The properties of the heavy oil feedstock A, B are shown in table 1. The catalyst used was DMMC-1 catalyst manufactured by catalyst division of China petrochemical Co., ltd. The properties are shown in Table 2.

Comparative examples 1 to 2

Comparative examples 1-2A schematic flow diagram of a process for producing ethylene and propylene by catalytic cracking of heavy oil as shown in FIG. 2 is shown in FIG. 2, in which heavy oil feed oil is preheated and then enters a catalytic cracking riser reactor 102 via a line 101 to contact with regenerated catalyst heated from a regenerator 106 via a line 109, the produced oil gas and catalyst enter a settler 103, the oil gas and catalyst are separated in the settler 103, and the separated catalyst with carbon is burned by entering the regenerator 106 via a line 105 after being stripped by a stripper 402. The air from line 108 in regenerator 106 burns off the catalyst to restore activity and then enters the bottom cycle of reactor 102 via line 109 to participate in the reaction and separated oil and gas enters fractionation column 111 via line 104. Product diesel 112 is withdrawn from the middle of fractionation column 111. Product slurry 113 is withdrawn from the bottom. The following products of gasoline obtained from the top of the fractionating tower 111 enter a post-absorption stabilizing system 115 through a pipeline 114, and products of gasoline 116, dry gas 401 and liquefied gas 117 separated by the stabilizing system, and the liquefied gas 117 enters a gas separation device 118 to separate propylene 119, propane 120 and four carbon components 121.

The carbon four component 121 enters the catalytic cracking riser reactor 110 and contacts the regenerated catalyst heated by the regenerator 106 via line 100, the produced oil gas and catalyst enter the settler 124 where the oil gas and catalyst are separated, and the separated catalyst with char is burned by the stripping section 402 via line 123 into the regenerator 206. The air from line 108 in regenerator 106 burns off the catalyst to restore activity and then enters the bottom loop of reactor 110 via line 100 to participate in the reaction. The dry gas 401 enters the separation system 124 to separate ethylene 125, other components 126 and ethane 123.

The reaction operating conditions of comparative examples 1 to 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) a heavy oil raw material enters a first reactor to contact and react with a first strand of regenerated catalyst from a regenerator, oil gas and catalyst mixture obtained by the reaction are subjected to gas-solid separation, and the separated spent catalyst is burnt and regenerated by the regenerator and is heated; the separated reaction oil gas is separated into dry gas, liquefied gas, gasoline, diesel oil and slurry oil by a first separation system, and ethylene, propylene, aromatic hydrocarbon products and four carbon components are further separated;

(2) Introducing a part of the carbon four components into a second reactor, carrying out contact reaction with a second strand of regenerated catalyst from the regenerator, and allowing the oil gas and catalyst mixture obtained by the reaction to enter a settler of the first reactor for gas-solid separation;

(3) The rest of the separated carbon four components enter an aromatization reactor to contact and react with an aromatization catalyst, and the reaction product is separated into dry gas, liquefied gas and gasoline rich in aromatic hydrocarbon by a second separation system to further separate ethylene, propylene and aromatic hydrocarbon products.

The reaction operating conditions for 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 feeds/feeds of the examples of feedstock a and feedstock B were reduced by 0.05 and 0.10, respectively, ethylene was increased by 0.33 and 0.48 percent, propylene was increased by 0.60 and 0.97 percent, respectively, and BTX was increased by 1.18 and 2.95 percent, respectively, as compared to the comparative examples.

TABLE 1

Raw oil	Raw material A	Raw material B
			Density (20 ℃ C.)/(kg/m) ³ )	934	862
C/wt％	87.15	86.3
			H/wt％	12.15	13.63
S/wt％	0.42	0.08
			N/wt％	0.22	0.05
Carbon residue value/wt%	5.58	0.10
			Distillation range/. Degree.C
5％	365	343
			10％	403	368
30％	479	410
			50％	545	437
70％	617	465
			Metal mass fraction/(μg/g)
Ni	9	0.1
			V	8	0.1

TABLE 2

TABLE 3 Table 3

Project	Comparative example 1	Example 1	Comparative example 2	Example 2
					Raw oil	Raw material A	Raw material A	Raw material B	Raw materialsB
Operating parameters of the feed reaction
					Catalyst	DMCC-1	DMCC-1	DMCC-1	DMCC-1
First reactor operating conditions
					Reaction pressure/MPa	0.2	0.2	0.28	0.28
Reaction temperature/. Degree.C	555	555	620	620
					Regenerator temperature/°c	690	690	710	710
Ratio of agent to oil	10	10	15	15
					Reaction space velocity/h ^-1	14	14	5	5
Atomizing steam/%	25	25	15	15
					Second reactor operating conditions
Carbon four feed/feedstock	0.25	0.20	0.40	0.3
					Reaction pressure/MPa	0.2	0.2	0.28	0.28
Reaction temperature/. Degree.C	600	600	640	640
					Regenerator temperature/°c	690	690	710	710
Ratio of agent to oil	8	8	12	12
					Reaction space velocity/h ^-1	50	50	8	8
Atomizing steam/%	10	10	25	25

TABLE 4 Table 4

Example numbering	Comparative example 1	Example 1	Comparative example 2	Example 2
					Product yield, wt%
H2-C2	13.69	13.98	16.11	17.01
					C3-C4	22.93	21.85	39.25	37.25
C5+ gasoline	29.44	30.16	26.89	27.85
					Diesel oil	16.30	16.35	8.68	8.74
Heavy oil	5.70	5.71	2.18	2.20
					Coke	11.94	11.95	6.89	6.95
Ethylene	8.00	8.33	10.67	11.15
					Propylene	19.05	19.65	30.26	31.23
BTX	9.35	10.53	7.5	10.45

Claims

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

2. The process for producing ethylene, propylene and aromatic hydrocarbons according to claim 1, wherein said heavy oil feedstock is selected from the group consisting of wax oil, atmospheric residue, vacuum residue and mixtures of one or more of organic compounds having a carbon number greater than 16.

3. The process for producing ethylene, propylene and aromatic hydrocarbons according to claim 1, wherein the catalyst in the steps (1) (2) is a catalytic cracking catalyst comprisingComprises an MFI structure molecular sieve, a Y-type molecular sieve, clay and a binder, wherein the content of the MFI structure molecular sieve is 5-60 based on the total weight of the catalystwt%The content of the Y-type molecular sieve is 1-40wtThe content of clay is 10-70 percentwtThe content of the binder is 5-40 percentwt%。

4. The method for producing ethylene, propylene and aromatic hydrocarbon according to claim 3, wherein the MFI structure molecular sieve is contained in an amount of 10 to 50 based on the total weight of the catalystwtThe content of the Y-type molecular sieve is 1-30 percentwtPercent, the clay content is 15-45 percentwtThe content of the binder is 5-30 percentwt%。

5. The process for producing ethylene, propylene and aromatic hydrocarbons according to claim 1, wherein said extrinsic carbon four components are carbon four components having an olefin content greater than 20%.

6. The process for producing ethylene, propylene and aromatic hydrocarbons according to claim 1, wherein said first reactor is one or a combination of a riser reactor, a turbulent bed reactor and a rapid bed reactor; the operating conditions of the first reactor were: 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 。

7. The process for producing ethylene, propylene and aromatic hydrocarbons according to claim 1, wherein said second reactor is one or a combination of a riser reactor, a turbulent bed reactor and a rapid bed reactor; the operating conditions of the 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 。

8. The process for producing ethylene, propylene and aromatic hydrocarbons according to claim 1, wherein said carbon four component separated in step (1) contains C4 olefins and C4 paraffins having an olefin content greater than20wt%。

9. The process for producing ethylene, propylene and aromatic hydrocarbons according to claim 8, wherein said olefin content in the carbon four component separated in step (1) is 40 to 90wt%。

10. The process for producing ethylene, propylene and aromatic hydrocarbons according to claim 1, wherein the operating conditions of the aromatization reactor in step (3) are: 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 。

11. The method for producing ethylene, propylene and aromatic hydrocarbons according to claim 1, wherein said aromatization catalyst comprises a molecular sieve, a metal active component and a refractory inorganic oxide support, said metal active component being selected from one or more of rare earth elements, VIB, VIII, IIB, VIIB group elements.

12. The process for producing ethylene, propylene and aromatic hydrocarbons according to claim 11, wherein said refractory inorganic oxide is selected from the group consisting of silica and alumina.

13. The process for producing ethylene, propylene and aromatic hydrocarbons according to claim 1, wherein the gas-solid separation in the steps (1) and (2) is carried out in a settler, the catalyst and the reaction oil-gas are separated by a cyclone gas-solid separator, and the separated catalyst is stripped in a stripper.

14. A catalytic conversion unit for producing ethylene, propylene and aromatics, for use in the process for producing ethylene, propylene and aromatics of any one of claims 1-13, comprising: the device comprises a first reactor, a second reactor, gas-solid separation equipment, a regenerator, a first oil-gas separation system, an aromatization reactor and a second oil-gas separation system; the regeneration agent outlet of the regenerator is communicated with the bottoms of the first reactor and the second reactor, the first reactor and the second reactor share one set of gas-solid separation equipment, the spent agent outlet of the gas-solid separation equipment is communicated with the regenerator, the oil-gas outlet of the gas-solid separation equipment is communicated with the first separation system, the C4 outlet of the first separation system is respectively communicated with the second reactor and the aromatization reactor, and the outlet of the aromatization reactor is communicated with the second separation system.

15. The catalytic conversion device for producing ethylene, propylene and aromatic hydrocarbons according to claim 14, wherein the first reactor, the second reactor are one or a combination of a riser reactor, a turbulent bed reactor and a fast bed reactor, and the aromatization reactor is a fixed bed reactor.