A catalytic conversion method for preparing light olefins

Abstract

The present disclosure relates to a catalytic conversion method for producing light olefins. The method of the present disclosure comprises subjecting olefin-rich raw materials, heavy raw materials and organic oxygen-containing compound raw materials to catalytic conversion reactions in different reaction zones of a catalytic conversion reactor, and selectively returning the separated multiple products to the reactor for continued reaction. The present disclosure integrates the processes for producing light olefins by petroleum routes and non-petroleum routes into the same catalytic conversion method, giving full play to the advantages of processes of different routes, and increasing the yield and selectivity of light olefins, especially the yield and selectivity of ethylene and propylene; the present disclosure also introduces heavy raw materials into the production process, realizing the recycling of heavy oil and reducing costs.

Description

Technical Field

[0001] The present application relates to petroleum refining and petrochemical processing, and specifically to a catalytic conversion method for producing low-carbon olefins. Background Art

[0002] Low-carbon olefins, such as olefins with 4 or less carbon atoms, are important chemical raw materials in the modern chemical industry. Ethylene, propylene and butene are the representatives, playing an increasingly important role in modern life. On the one hand, with the continuous acceleration of economic development, the demand for light oil products and clean fuel oil in various industries has also increased rapidly. On the other hand, with the continuous increase in oil field production, the available output of conventional crude oil is decreasing, and the quality of crude oil is getting worse and worse, tending to be inferior and heavy. Although my country's light olefin production capacity has grown rapidly, it still cannot meet the domestic market demand for light olefins. Common industrial products obtained based on low-carbon olefins include: polyethylene, ethylene oxide, ethylene glycol, polyvinyl chloride, styrene, vinyl acetate, etc. produced by ethylene; acrylonitrile, propylene oxide, acetone, etc. produced by propylene; butadiene, methyl ethyl ketone, sec-butyl alcohol, butylene oxide and butene polymers and copolymers produced by butene; butyl rubber, polyisobutylene rubber and various plastics produced by isobutylene. It can be seen that the production processes of many important organic chemical raw materials involve the use of ethylene, propylene and butene.

[0003] The production of low-carbon olefins worldwide is divided into petroleum and non-petroleum routes. The traditional steam cracking route for producing ethylene and propylene has a large demand for light hydrocarbons, naphtha and other chemical light hydrocarbons. It is estimated that 700,000 tons of chemical light oil will be needed in 2025. However, domestic crude oil is generally heavy, and chemical light oil is difficult to meet the demand for the production of ethylene, propylene and butene raw materials. In the case of insufficient petroleum resources, the diversification of steam cracking raw materials has become the development trend of the ethylene and propylene industries. The main raw materials for steam cracking are light hydrocarbons (such as ethane, propane and butane), naphtha, diesel, condensate and hydrogenated tail oil. Among them, the mass fraction of naphtha accounts for more than 50%. The ethylene yield of typical naphtha steam cracking is about 29%-34%, and the propylene yield is 13%-16%. The low ethylene-propylene output ratio is difficult to meet the current demand for low-carbon olefins.

[0004] CN101092323A discloses a method for preparing ethylene and propylene by using a C4-C8 olefin mixture as a raw material, reacting at a reaction temperature of 400-600°C and an absolute pressure of 0.3-1.1 KPa, and recycling 30-90% by weight of the C4 fraction into a reactor through a separation device for further cracking. The method mainly improves the olefin conversion rate by recycling the C4 fraction, and the obtained ethylene and propylene are not less than 62% of the total amount of the raw olefins, but the ethylene / propylene ratio is relatively small, and cannot be flexibly adjusted according to market demand, and the reaction selectivity is low.

[0005] CN101239878A discloses a method of using a rich olefin mixture of C4 or higher olefins as a raw material, and carrying out the reaction at a reaction temperature of 400-680°C, a reaction pressure of -0.09-1.0 MPa, and a weight space velocity of 0.1 to 50 h-1. The product ethylene / propylene ratio is relatively low, less than 0.41. As the temperature rises, the ethylene / propylene ratio increases, and at the same time, the hydrogen, methane and ethane increase.

[0006] The non-petroleum route to produce low-carbon olefins is mainly based on organic oxygen-containing compounds represented by methanol or dimethyl ether as raw materials to produce low-carbon olefins mainly composed of ethylene and propylene. Methanol or dimethyl ether is a typical organic oxygen-containing compound. The reaction characteristics of producing low-carbon olefins are rapid reaction, strong heat release, low alcohol ratio and long reaction induction period, but the MTO process has the disadvantage of easy catalyst deactivation.

[0007] Therefore, the art still lacks a catalytic conversion mode that can integrate multiple catalytic conversion reaction forms and increase the production of high-value low-carbon olefins ethylene and propylene, and improve the selectivity of ethylene and propylene. Summary of the invention

[0008] The purpose of the present disclosure is to provide a catalytic conversion method for producing light olefins. The catalytic conversion method provided by the present disclosure can significantly improve the yield and selectivity of ethylene, propylene and butene.

[0009] In order to achieve the above-mentioned object, the present disclosure provides a catalytic conversion method for preparing light olefins, which method comprises the following steps: (1) under first catalytic conversion reaction conditions, contacting an olefin-rich raw material with a catalytic conversion catalyst at a temperature of above 650° C. in a first reaction zone of a catalytic conversion reactor and performing a first catalytic conversion reaction to obtain a first mixed stream; the olefin-rich raw material contains more than 50% by weight of olefins; (2) under second catalytic conversion reaction conditions, contacting a heavy raw material and an organic oxygen-containing compound raw material with the first mixed stream from the first reaction zone in a second reaction zone of the catalytic conversion reactor and performing a second catalytic conversion reaction to obtain reaction oil gas and a catalyst to be produced. (3) subjecting the reaction oil and gas to a first separation treatment to separate ethylene, propylene, butene, organic oxygen-containing compounds, a first catalytic cracking distillate oil and a second catalytic cracking distillate oil; the initial distillation point of the first catalytic cracking distillate oil is any temperature greater than 20°C and less than 140°C, the final distillation point of the second catalytic cracking distillate oil is any temperature less than 550°C and greater than 250°C, and the cut point between the first catalytic cracking distillate oil and the second catalytic cracking distillate oil is any temperature between 140-250°C; subjecting the first catalytic cracking distillate oil to a second separation treatment to separate an olefin-rich stream; (4) returning the olefin-rich stream to the catalytic conversion reactor for continued reaction.

[0010] Optionally, the method includes: allowing the reaction oil and gas to enter a product fractionation device for a first separation treatment to separate ethylene, propylene, butene, the organic oxygen-containing compounds, the first catalytic cracking distillate oil and the second catalytic cracking distillate oil; allowing the first catalytic cracking distillate oil to enter an olefin separation device for a second separation treatment to separate the olefin-rich stream; and returning the olefin-rich stream to the first reaction zone of the catalytic conversion reactor to continue reacting.

[0011] Optionally, the method includes: allowing the reaction oil and gas to enter a product fractionation device for a first separation treatment to separate ethylene, propylene, butene, the organic oxygen-containing compounds, the first catalytic cracking distillate oil and the second catalytic cracking distillate oil; allowing the first catalytic cracking distillate oil to enter an olefin separation device for a third separation treatment to separate a large molecular olefin flow and a small molecular olefin flow; returning the small molecular olefin flow as the olefin-rich flow to the first reaction zone of the catalytic conversion reactor for continued reaction; and returning the large molecular olefin flow to the second reaction zone of the catalytic conversion reactor for continued reaction.

[0012] Optionally, the method further comprises: returning the separated butene to the first reaction zone of the catalytic conversion reactor for further reaction; preferably, the butene returned to the catalytic conversion reactor for further reaction contacts the catalytic conversion catalyst before the olefin-rich logistics.

[0013] Optionally, the reaction conditions for returning the butene to the catalytic reactor for continued reaction include: a reaction temperature of 650-800°C, a reaction pressure of 0.05-1MPa, a reaction time of 0.01-10 seconds, and a weight ratio of the catalytic conversion catalyst to the returned butene of (20-200):1; preferably, the reaction temperature is 680-780°C, the reaction pressure is 0.1-0.8MPa, the reaction time is 0.05-8 seconds, and the weight ratio of the catalytic conversion catalyst to the returned butene of (30-180):1.

[0014] Optionally, the first catalytic conversion reaction conditions include: reaction temperature of 600-800°C, preferably 630-780°C; reaction pressure of 0.05-1MPa, preferably 0.1-0.8MPa; reaction time of 0.01-100 seconds, preferably 0.1-80 seconds; the weight ratio of the catalytic conversion catalyst to the olefin-rich feedstock is (1-200):1, preferably (3-180):1.

[0015] Optionally, the second catalytic conversion reaction conditions include: a reaction temperature of 300-650°C, preferably 400-600°C; a reaction pressure of 0.01-1MPa, preferably 0.05-1MPa; a reaction time of 0.01-100 seconds, preferably 0.1-80 seconds; a weight ratio of the catalytic conversion catalyst to the heavy raw material of (1-100):1, preferably (3-70):1; a weight ratio of the catalytic conversion catalyst to the organic oxygen-containing compound raw material of (1-100):1, preferably (3-50):1; the reaction temperature of the first catalytic conversion reaction is 30-380°C higher than the reaction temperature of the second catalytic conversion reaction.

[0016] Optionally, the second reaction zone is divided into a second reaction zone upstream and a second reaction zone downstream according to the flow direction of the reactants, with the feed position of the organic oxygen-containing compound raw material as the boundary, and the second reaction zone downstream is located after the feed position of the organic oxygen-containing compound raw material; the method also includes: making the first mixed material flow from the first reaction zone contact with the heavy raw material upstream of the second reaction zone and undergoing a catalytic conversion reaction to obtain a second mixed material flow; and then making the second mixed material flow contact with the organic oxygen-containing compound raw material downstream of the second reaction zone and undergoing a catalytic conversion reaction to obtain the reaction oil gas and the catalyst to be generated.

[0017] Optionally, the catalytic conversion reaction conditions of the heavy raw material and the first mixed stream in the upstream of the second reaction zone include: a reaction temperature of 400-650°C, preferably 450-600°C; a reaction pressure of 0.05-1MPa, preferably 0.1-0.8MPa; a reaction time of 0.01-100 seconds, preferably 0.1-80 seconds; a weight ratio of the catalytic conversion catalyst to the heavy raw material of (1-100):1, preferably (3-70):1; the organic oxygen-containing compound raw material and the second mixed stream in the second reaction zone are The catalytic conversion reaction conditions in the downstream of the zone include: reaction temperature of 300-550°C, preferably 400-530°C; reaction pressure of 0.01-1MPa, preferably 0.05-1MPa; reaction time of 0.01-100 seconds, preferably 0.1-80 seconds; the reaction temperature in the upstream of the second reaction zone is 0-200°C higher than the reaction temperature in the downstream of the second reaction zone, preferably 10-190°C higher; the weight ratio of the catalytic conversion catalyst to the organic oxygen-containing compound raw material is (1-100):1, preferably (3-50):1.

[0018] Optionally, the method further comprises: returning the separated organic oxygen-containing compound to the second reaction zone of the catalytic conversion reactor for further reaction.

[0019] Optionally, the catalytic conversion reactor is a riser reactor, preferably a variable diameter riser reactor.

[0020] Optionally, the method further comprises: regenerating the spent catalyst by burning it to obtain a regenerated catalyst; and returning the regenerated catalyst to the first reaction zone of the catalytic conversion reactor as the catalytic conversion catalyst.

[0021] Optionally, the olefin content in the olefin-rich feedstock is 80% by weight or more, preferably 90% by weight or more, and more preferably a pure olefin feedstock; the heavy oil is selected from petroleum hydrocarbons and / or mineral oils; the petroleum hydrocarbons are selected from one or more of vacuum gas oil, atmospheric gas oil, coking gas oil, deasphalted oil, vacuum residue oil, atmospheric residue oil and heavy aromatic raffinate oil; the mineral oil is selected from one or more of coal liquefaction oil, oil sand oil and shale oil; optionally, the organic oxygen-containing compound feedstock comprises at least one of methanol, ethanol, dimethyl ether, methyl ethyl ether and ethyl ether.

[0022] Optionally, the olefin-rich feedstock comes from at least one of the C5 or higher fractions produced by an alkane dehydrogenation unit, the C5 or higher fractions produced by a catalytic cracking unit of an oil refinery, the C5 or higher fractions produced by a steam cracking unit of an ethylene plant, the C5 or higher olefin-rich fraction produced as a by-product of MTO, and the C5 or higher olefin-rich fraction produced as a by-product of MTP; optionally, the alkane feedstock of the alkane dehydrogenation unit comes from at least one of naphtha, aromatic raffinate and other light hydrocarbons.

[0023] Optionally, based on the total weight of the catalytic conversion catalyst, the catalytic conversion catalyst comprises 1-50 weight % of molecular sieves, 5-99 weight % of inorganic oxides and 0-70 weight % of clay; the molecular sieves include one or more of large-pore molecular sieves, medium-pore molecular sieves and small-pore molecular sieves; based on the total weight of the catalytic conversion catalyst, the catalytic conversion catalyst also includes 0.1 weight %-3 weight % of metal ions, and the metal ions are selected from one or more of Group VIII metals, Group IVA metals and rare earth metals.

[0024] Optionally, under hydrogenation reaction conditions, the second catalytic cracking distillate is contacted with a hydrogenation catalyst to react to obtain a hydrogenated second catalytic cracking distillate, and the hydrogenated second catalytic cracking distillate is returned to the catalytic conversion reactor for further reaction; wherein the hydrogenation reaction conditions include: a hydrogen partial pressure of 3.0-20.0 MPa, a reaction temperature of 300-450° C., a hydrogen-to-oil volume ratio of 300-2000, and a volume space velocity of 0.1-3.0 h -1, based on the total weight of the hydrogenation catalyst, the hydrogenation catalyst comprises 20-90 wt % of a carrier, 10-80 wt % of a supported metal and 0-10 wt % of an additive; wherein the carrier is alumina and / or amorphous silicon-alumina, the additive is selected from at least one of fluorine, phosphorus, titanium and platinum, and the supported metal is a VIB group metal and / or a VIII group metal; preferably, the VIB group metal is Mo or / and W, and the VIII group metal is Co or / and Ni.

[0025] Optionally, the olefins in the olefin-rich logistics are C5 or higher olefins; the content of C5 or higher olefins in the olefin-rich logistics is 50% by weight or more, preferably 80% by weight or more.

[0026] Through the above technical scheme, the present disclosure provides a catalytic conversion method for preparing low-carbon olefins. The method first subjects a raw material rich in olefins to a first catalytic conversion reaction, and then subjects the obtained first mixed stream to a heavy raw material and an organic oxygen-containing compound raw material for a second catalytic conversion reaction to generate reaction oil gas and a catalyst to be generated; after separation and treatment of the reaction oil gas, ethylene, propylene, butene, unconverted organic oxygen-containing compounds and a stream rich in olefins can be obtained. The method of the present disclosure integrates the processes for preparing low-carbon olefins by petroleum routes and non-petroleum routes into the same catalytic conversion method, giving full play to the advantages of processes of different routes, and improving the yield and selectivity of low-carbon olefins, especially the yield and selectivity of ethylene and propylene; the present disclosure also returns the separated olefin-rich stream to the catalytic conversion reactor for continued reaction, further improving the utilization rate of petrochemical resources; the present disclosure also introduces heavy raw materials into the production process, realizing the recycling of heavy oil and reducing costs.

[0027] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings: Figure 1 It is a schematic flow chart of a catalytic conversion method for producing light olefins provided in the first specific embodiment of the present disclosure. Figure 2 It is a schematic flow chart of a catalytic conversion method for producing light olefins provided in a second specific embodiment of the present disclosure. Figure 3 It is a schematic flow chart of a catalytic conversion method for producing light olefins provided in a third specific embodiment of the present disclosure. Figure 4 It is a schematic flow chart of a catalytic conversion method for producing light olefins provided in the fourth specific embodiment of the present disclosure.

[0029] BRIEF DESCRIPTION OF THE DRAWINGS

[0030] ⅠFirst reaction zone ⅡSecond reaction zone

[0031] 1 pipeline 2 reactor 3 pipeline

[0032] 4 pipelines 5 pipelines 6 pipelines

[0033] 7 pipeline 8 outlet section 9 settler

[0034] 10 Gas collecting chamber 11 Stripping section 12 Pipeline

[0035] 13 inclined tube 14 regenerator 15 pipeline

[0036] 16 pipeline 17 pipeline 18 pipeline

[0037] 19 Large oil and gas pipeline 20 Product separation unit 21 Pipeline

[0038] 22 pipeline 23 pipeline 24 pipeline

[0039] 25 pipeline 26 pipeline 27 pipeline

[0040] 28 pipeline 29 olefin separation unit 30 pipeline

[0041] 31 pipeline 32 hydroprocessing reactor 33 pipeline

[0042] 34 pipeline DETAILED DESCRIPTION

[0043] The specific embodiments of the present disclosure are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure, and are not used to limit the present disclosure.

[0044] The inventors of the present disclosure have conducted a large number of alkane and olefin catalytic cracking tests and unexpectedly found that the yield and selectivity of light olefins produced by olefin cracking are significantly better than those of alkanes when olefins and alkanes are reacted under the same catalytic cracking reaction conditions; and the difference in product distribution of olefin and alkane catalytic cracking is also obvious. The inventors also found that in the process of producing light olefins by petroleum route, the introduction of organic oxygen-containing compound raw materials from non-petroleum route processes to jointly produce light olefins can significantly improve the yield and selectivity of light olefins in the product.

[0045] The present disclosure provides a catalytic conversion method for preparing light olefins, which method comprises the following steps: (1) under first catalytic conversion reaction conditions, contacting an olefin-rich feedstock with a catalytic conversion catalyst at a temperature of more than 650° C. in a first reaction zone of a catalytic conversion reactor and performing a first catalytic conversion reaction to obtain a first mixed stream; the olefin-rich feedstock contains more than 50% by weight of olefins; (2) under second catalytic conversion reaction conditions, contacting a heavy feedstock and an organic oxygen-containing compound feedstock with the first mixed stream from the first reaction zone in a second reaction zone of the catalytic conversion reactor and performing a second catalytic conversion reaction to obtain reaction oil gas and a catalyst to be regenerated; (3) The reaction oil and gas are subjected to a first separation treatment to separate ethylene, propylene, butene, organic oxygen-containing compounds, a first catalytic cracking distillate oil and a second catalytic cracking distillate oil; the initial distillation point of the first catalytic cracking distillate oil is any temperature greater than 20°C and less than 140°C, the final distillation point of the second catalytic cracking distillate oil is any temperature less than 550°C and greater than 250°C, and the cut point between the first catalytic cracking distillate oil and the second catalytic cracking distillate oil is any temperature between 140-250°C; the first catalytic cracking distillate oil is subjected to a second separation treatment to separate an olefin-rich stream; (4) the olefin-rich stream is returned to the catalytic conversion reactor to continue the reaction.

[0046] The present disclosure provides a catalytic conversion method for producing low-carbon olefins. The method first subjects a raw material rich in olefins to a first catalytic conversion reaction, and then subjects the obtained first mixed stream to a heavy raw material and an organic oxygen-containing compound raw material for a second catalytic conversion reaction to generate reaction oil gas and a catalyst to be produced; after separation and treatment of the reaction oil gas, ethylene, propylene, butene, organic oxygen-containing compounds and olefin-rich logistics can be obtained. The method of the present disclosure integrates the processes for producing low-carbon olefins by petroleum routes and non-petroleum routes into the same catalytic conversion method, giving full play to the advantages of processes of different routes, and improving the yield and selectivity of low-carbon olefins, especially the yield and selectivity of ethylene and propylene; the present disclosure also returns the separated olefin-rich logistics to the catalytic conversion reactor for continued reaction, further improving the utilization rate of petrochemical resources; the present disclosure also introduces heavy raw materials into the production process, realizing the recycling of heavy oil and reducing costs.

[0047] In a preferred embodiment, the olefin content in the olefin-rich feedstock is 80% by weight or more, preferably 90% by weight or more, and more preferably a pure olefin feedstock; the olefins in the olefin-rich feedstock are selected from olefins with 4 or more carbon atoms or olefins with 5 or more carbon atoms. The inventors found in their research that increasing the olefin content in the olefin-rich feedstock is beneficial to increasing the yield and selectivity of light olefins in the product.

[0048] In the present disclosure, in one embodiment, the olefin-rich feedstock may come only from the olefin-containing logistics containing C5 or more olefins separated from the catalytic conversion product of the heavy oil feedstock, that is, the olefin-rich feedstock is the olefin recycled within the system; in another embodiment, the olefin-rich feedstock, in addition to the above-mentioned olefin-containing logistics containing C5 or more olefins, may also contain additional olefin feedstock, and there is no special requirement for the amount of the additional olefin feedstock.

[0049] In some embodiments of the present disclosure, the olefin-rich raw material may come from any one or more of the following sources: a C5 or higher fraction produced by an alkane dehydrogenation unit, a C5 or higher fraction produced by a catalytic cracking unit of an oil refinery, a C5 or higher fraction produced by a steam cracking unit of an ethylene plant, MTO (methanol to olefins) and a C5 or higher olefin-rich fraction produced as a byproduct, and a C5 or higher olefin-rich fraction produced as a byproduct of MTP (methanol to propylene). In a further embodiment, the alkane raw material used to produce the olefin-rich raw material by dehydrogenating the alkane may come from at least one of naphtha, aromatic raffinate and / or other light hydrocarbons. In actual production, alkane products produced by other different petrochemical units may also be used.

[0050] Furthermore, in an embodiment of recycling butene products, the olefins in the hydrocarbon oil feedstock come from the C4 and above fractions produced by dehydrogenation of alkane feedstocks, the C4 and above fractions produced by a catalytic cracking unit in a refinery, the C4 and above fractions produced by a steam cracking unit in an ethylene plant, the C4 and above olefin-rich fractions produced as a by-product of MTO, and the C4 and above olefin-rich fractions produced as a by-product of MTP; and the alkane feedstock is selected from at least one of naphtha, aromatic raffinate and light hydrocarbons of other units.

[0051] In a specific embodiment, the following method can be used to carry out alkane dehydrogenation: under dehydrogenation reaction conditions, the alkane is contacted with a dehydrogenation catalyst in a dehydrogenation reactor to react to obtain a feedstock rich in olefins.

[0052] The dehydrogenation reaction conditions include: the inlet temperature of the dehydrogenation treatment reactor is 400-700°C, the volume space velocity of the alkane is 500-5000 hours -1 , the pressure of the contact reaction is 0.04-1.1 bar.

[0053] The dehydrogenation catalyst is composed of a carrier, an active component and an auxiliary agent supported on the carrier; optionally, based on the total weight of the dehydrogenation catalyst, the content of the carrier is 60-90% by weight, the content of the active component is 8-35% by weight, and the content of the auxiliary agent is 0.1-5% by weight; optionally, the carrier is alumina containing a modifier; wherein, based on the total weight of the dehydrogenation catalyst, the content of the modifier is 0.1-2% by weight, wherein the modifier may be La and / or Ce; optionally, the active component is chromium; optionally, the auxiliary agent may be a bismuth and alkali metal composition or a bismuth and alkaline earth metal component composition; wherein the molar ratio of bismuth to the active component is 1:(5-50); the molar ratio of bismuth to the alkali metal component is 1:(0.1-5); the molar ratio of bismuth to the alkaline earth metal component is 1:(0.1-5); the alkali metal component may be selected from one or more of Li, Na and K; the alkaline earth metal component may be selected from one or more of Mg, Ca and Ba.

[0054] In a preferred embodiment, the heavy oil used in the present disclosure is selected from petroleum hydrocarbons and / or mineral oils; the petroleum hydrocarbons are selected from one or more of vacuum gas oil, atmospheric gas oil, coker gas oil, deasphalted oil, vacuum residue oil, atmospheric residue oil and heavy aromatic raffinate oil; the mineral oil is selected from one or more of coal liquefaction oil, oil sand oil and shale oil.

[0055] In one embodiment, the organic oxygen-containing compound raw material comprises at least one of methanol, ethanol, dimethyl ether, methyl ethyl ether and ethyl ether. In a specific embodiment, the organic oxygen-containing compound raw material can be from a synthesis gas to oxygen-containing compound process, such as a synthesis gas to methanol process, a synthesis gas to ethanol process, wherein the synthesis gas is, for example, coal-based synthesis gas and / or natural gas-based synthesis gas.

[0056] In a specific embodiment, the first catalytic conversion reaction conditions include: a reaction temperature of 600-800°C, preferably 630-780°C; a reaction pressure of 0.05-1MPa, preferably 0.1-0.8MPa; a reaction time of 0.01-100 seconds, preferably 0.1-80 seconds; a weight ratio of the catalytic conversion catalyst to the olefin-rich feedstock of (1-200):1, preferably (3-180):1; the second catalytic conversion reaction conditions include: a reaction temperature of 600-800°C, preferably 630-780°C; a reaction pressure of 0.05-1MPa, preferably 0.1-0.8MPa; a reaction time of 0.01-100 seconds, preferably 0.1-80 seconds; a weight ratio of the catalytic conversion catalyst to the olefin-rich feedstock of (1-200):1, preferably (3-180):1; The reaction temperature is 300-650°C, preferably 400-600°C; the reaction pressure is 0.01-1MPa, preferably 0.05-1MPa; the reaction time is 0.01-100 seconds, preferably 0.1-80 seconds; the weight ratio of the catalytic conversion catalyst to the heavy raw material is (1-100):1, preferably (3-70):1; the weight ratio of the catalytic conversion catalyst to the organic oxygen-containing compound raw material is (1-100):1, preferably (3-50):1. Optionally, the reaction temperature of the first catalytic conversion reaction is 30-380°C higher than the reaction temperature of the second catalytic conversion reaction.

[0057] In the present disclosure, the reaction temperature of the first catalytic conversion refers to the outlet temperature of the first reaction zone; the reaction temperature of the second catalytic conversion refers to the outlet temperature of the second reaction zone.

[0058] In the present disclosure, the heavy feedstock and the organic oxygen-containing compound feedstock are contacted with the first mixed stream from the first reaction zone in the second reaction zone of the catalytic conversion reactor and subjected to the second catalytic conversion reaction, including the following situations: 1) the heavy feedstock and the organic oxygen-containing compound feedstock enter the second reaction zone together, contact with the first mixed stream and react, for example Figure 4 As shown, the mixed raw material obtained by mixing the heavy raw material and the organic oxygen-containing compound raw material is sent to the second reaction zone to contact and react with the first mixed material flow; 2) as Figure 3 As shown, the first mixed stream is first contacted with a heavy raw material to react, and then the obtained mixed stream is contacted with an organic oxygen-containing compound raw material to react; 3) the first mixed stream is first contacted with an organic oxygen-containing compound raw material to react, and then the obtained mixed stream is contacted with a heavy raw material to react.

[0059] In a preferred embodiment, Figure 3 As shown, the second reaction zone is divided into a second reaction zone upstream and a second reaction zone downstream according to the flow direction of the reactants, with the feed position of the organic oxygen-containing compound raw material as the boundary, and the second reaction zone downstream is located after the feed position of the organic oxygen-containing compound raw material; the method also includes:

[0060] The first mixed stream from the first reaction zone is contacted with the heavy feedstock upstream of the second reaction zone and subjected to a catalytic conversion reaction to obtain a second mixed stream, and then the second mixed stream is contacted with the organic oxygen-containing compound feedstock downstream of the second reaction zone and subjected to a catalytic conversion reaction to obtain reaction oil gas and spent catalyst. This embodiment can further improve the yield and selectivity of ethylene and propylene.

[0061] In the present disclosure, the second reaction zone upstream and the second reaction zone downstream are defined according to the flow direction of the material flow in the catalytic conversion reactor.

[0062] In this specific embodiment, further, the catalytic conversion reaction conditions of the heavy raw material and the first mixed stream in the upstream of the second reaction zone include: reaction temperature of 400-650°C, preferably 450-600°C; reaction pressure of 0.05-1MPa, preferably 0.1-0.8MPa; reaction time of 0.01-100 seconds, preferably 0.1-80 seconds; weight ratio of the catalytic conversion catalyst to the heavy raw material is (1-100):1, preferably (3-70):1; the organic oxygen-containing compound raw material and the second mixed stream in the upstream of the second reaction zone are: The catalytic conversion reaction conditions in the downstream of the second reaction zone include: reaction temperature of 300-550°C, preferably 400-530°C; reaction pressure of 0.01-1MPa, preferably 0.05-1MPa; reaction time of 0.01-100 seconds, preferably 0.1-80 seconds; the reaction temperature in the upstream of the second reaction zone is 0-200°C higher than the reaction temperature in the downstream of the second reaction zone, preferably 10-190°C higher; the weight ratio of the catalytic conversion catalyst to the organic oxygen-containing compound raw material is (1-100):1, preferably (3-50):1.

[0063] Specifically, in the present disclosure, the reaction temperature in the upstream of the second reaction zone refers to the outlet temperature of the upstream of the second reaction zone, and the reaction temperature in the downstream of the second reaction zone refers to the outlet temperature of the downstream of the second reaction zone.

[0064] In one embodiment, the method may further include: returning the separated organic oxygen-containing compound to the second reaction zone of the catalytic conversion reactor for further reaction.

[0065] In one specific embodiment, the separated organic oxygen-containing compound is returned to the downstream of the second reaction zone to continue the reaction.

[0066] In a specific embodiment, the catalytic conversion method provided by the present disclosure further comprises: allowing the reaction oil gas to enter a product fractionation device for a first separation treatment to separate ethylene, propylene, butene, the organic oxygen-containing compound, the first catalytic cracking distillate oil, and the second catalytic cracking distillate oil;

[0067] allowing the first catalytic cracking fraction oil to enter an olefin separation unit for a second separation treatment to separate the olefin-rich stream;

[0068] The olefin-rich stream is returned to the first reaction zone of the catalytic conversion reactor to continue the reaction.

[0069] In another specific embodiment, the catalytic conversion method provided by the present disclosure also includes: allowing the reaction oil gas to enter the product fractionation device for a first separation treatment to separate ethylene, propylene, butene, the organic oxygen-containing compound, the first catalytic cracking distillate oil and the second catalytic cracking distillate oil; allowing the first catalytic cracking distillate oil to enter the olefin separation device for a third separation treatment to separate a large molecular olefin flow and a small molecular olefin flow; allowing the small molecular olefin flow to return to the first reaction zone of the catalytic conversion reactor as the olefin-rich flow to continue to react; allowing the large molecular olefin flow to return to the second reaction zone of the catalytic conversion reactor to continue to react. This embodiment separates the first catalytic cracking distillate oil into a large molecular olefin flow and a small molecular olefin flow, and returns the two olefin flows to different positions of the catalytic conversion reactor for continued reaction, which can make full use of the properties of the olefin flows of different molecules themselves, improve the reaction conversion rate, and avoid the occurrence of side reactions.

[0070] In the present disclosure, the large molecular olefin logistics refers to olefins with larger molecules contained in the first catalytic cracking distillate oil, such as C10 and above olefins; the small molecular olefin logistics refers to olefins with smaller molecules contained in the first catalytic cracking distillate oil, such as C5-C9 olefins.

[0071] In the present disclosure, the second separation treatment and the third separation treatment are separation methods conventionally selected in the art.

[0072] In one embodiment, the catalytic conversion method provided by the present disclosure further comprises: returning the separated butene to the first reaction zone of the catalytic conversion reactor for further reaction.

[0073] In a preferred embodiment, the butene returned to the catalytic conversion reactor for continued reaction contacts the catalytic conversion catalyst before the olefin-rich logistics. In this embodiment, in the catalytic conversion reactor, the high-temperature catalytic conversion catalyst contacts and reacts with the butene returned to the reactor first, and then contacts and reacts with the olefin-rich logistics. The difficulty of hydrocarbon cracking increases with the decrease of carbon number, and the energy required for butene cracking is relatively high. Therefore, the present disclosure allows butene to contact with the high-temperature catalytic conversion catalyst first, and then allows olefins above C4 to contact with the catalytic conversion catalyst. This can not only improve the butene conversion rate and the selectivity of the products ethylene and propylene, but also avoid the generation of more by-products by feeding olefins at the same time, thereby achieving efficient utilization of resources.

[0074] In a specific embodiment, the reaction conditions for returning the butene to the catalytic reactor for continued reaction include: a reaction temperature of 650-800°C, a reaction pressure of 0.05-1MPa, a reaction time of 0.01-10 seconds, and a weight ratio of the catalytic conversion catalyst to the returned butene of (20-200):1.

[0075] Preferably, the reaction temperature is 680-780° C., the reaction pressure is 0.1-0.8 MPa, the reaction time is 0.05-8 seconds, and the weight ratio of the catalytic conversion catalyst to the returned butene is (30-180):1.

[0076] In one embodiment, the catalytic conversion method of the present disclosure further includes: returning the separated organic oxygen-containing compound to the second reaction zone of the catalytic conversion reactor for further reaction, thereby further improving the feedstock conversion rate and the ethylene and propylene yields.

[0077] In one embodiment, the catalytic conversion method provided by the present disclosure may further include: under hydrogenation reaction conditions, contacting and reacting the second catalytic cracking distillate with a hydrogenation catalyst to obtain a hydrogenated second catalytic cracking distillate, and returning the hydrogenated second catalytic cracking distillate to the catalytic conversion reactor for further reaction. The second catalytic cracking distillate can be used as a catalytic cracking feedstock for further reaction after being hydrogenated in the present disclosure, thereby expanding the source of raw materials, improving resource utilization, and further improving the yield of light olefins.

[0078] In a specific embodiment, the hydrogenation reaction conditions include: hydrogen partial pressure of 3.0-20.0 MPa, reaction temperature of 300-450°C, hydrogen-oil volume ratio of 300-2000, volume space velocity of 0.1-3.0 hours -1 .

[0079] In a specific embodiment, the catalytic conversion method provided by the present disclosure includes: returning the hydrogenated second catalytic cracking distillate oil to the upstream of the second reaction zone of the catalytic conversion reactor for further reaction. In this embodiment, the high-temperature catalytic conversion catalyst is first contacted and reacted with the olefin-rich logistics returned to the reactor, and then contacted and reacted with the hydrogenated second catalytic cracking distillate oil returned to the catalytic conversion reactor, so that the saturated hydrocarbons with a larger carbon number contained in the hydrogenated second catalytic cracking distillate oil are first cracked into C5-C9 olefins under relatively mild reaction conditions, and then the obtained olefins are returned to the catalytic cracking reactor for high-temperature cracking again, thereby further improving the ethylene yield.

[0080] In a specific embodiment, the catalytic conversion reactor used in the present disclosure can be selected from one or a series combination of a riser, a fluidized bed with a constant linear velocity, a fluidized bed with a constant diameter, an upward conveying line and a downward conveying line, wherein the riser can be a constant diameter riser reactor or a variable diameter fluidized bed reactor, and the fluidized bed reactor can be a fluidized bed with a constant linear velocity or a fluidized bed with a constant diameter.

[0081] In a preferred embodiment, the present disclosure uses a riser reactor as a catalytic conversion reactor; in a more preferred embodiment, the catalytic conversion reactor is a variable diameter riser reactor.

[0082] In a preferred embodiment, the present disclosure can also regenerate the spent catalyst by burning it to obtain a regenerated catalyst; and return the regenerated catalyst to the first reaction zone of the catalytic conversion reactor as the catalytic conversion catalyst, thereby realizing the recycling of the catalytic conversion catalyst.

[0083] In a specific embodiment, based on the total weight of the catalytic conversion catalyst, the catalytic conversion catalyst comprises 1-50 wt% of molecular sieve, 5-99 wt% of inorganic oxide and 0-70 wt% of clay.

[0084] The molecular sieve, as an active component of the catalytic conversion catalyst, can be selected from one or more of the molecular sieves including large-pore molecular sieves, medium-pore molecular sieves and small-pore molecular sieves.

[0085] In one embodiment, the mesoporous molecular sieve may be a ZSM molecular sieve, and further, the ZSM molecular sieve may be selected from one or more of ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-35, and ZSM-48.

[0086] In one embodiment, the small pore molecular sieve may be a SAPO molecular sieve and / or a SSZ molecular sieve, further, the SAPO molecular sieve may be selected from one or more of SAPO-34, SAPO-11, and SAPO-47, and the SSZ molecular sieve may be selected from one or more of SSZ-13, SSZ-39, and SSZ-62. In a further embodiment, the medium pore molecular sieve accounts for 50% to 100% by weight of the total weight of the molecular sieve, preferably 70% to 100% by weight, and the small pore molecular sieve accounts for 0% to 50% by weight of the total weight of the molecular sieve, preferably 0% to 30% by weight.

[0087] In one embodiment, the macroporous molecular sieve can be selected from one or a mixture of rare earth Y molecular sieve, rare earth hydrogen Y molecular sieve, ultrastable Y molecular sieve, high silicon Y molecular sieve, Beta molecular sieve and other molecular sieves of similar structure.

[0088] In a preferred embodiment, metal ions can also be loaded on the molecular sieve, and the metal ions can be selected from one or more of Group VIII metals, Group IVA metals and rare earth metals; in a more preferred embodiment, based on the total weight of the catalytic conversion catalyst, the weight content of the loaded metal ions is 0.1%-3%, which can further improve the catalytic capacity of the catalytic conversion catalyst.

[0089] In a preferred embodiment, the inorganic oxide is selected from silicon dioxide (SiO2) and / or aluminum oxide (Al2O3) as the binder; and the clay is selected from kaolin and / or halloysite as the matrix (ie, carrier).

[0090] In one embodiment, the hydrogenation catalyst comprises a carrier, a metal component supported on the carrier, and an optional additive, wherein the carrier is alumina and / or amorphous silicon aluminum, the metal component is a VIB group metal and / or a VIII group metal, and the additive is selected from at least one of fluorine, phosphorus, titanium and platinum. The VIB group metal is Mo or / and W, and the VIII group metal is Co or / and Ni; based on the total weight of the hydrogenation catalyst, the content of the additive is 0-10% by weight, the content of the VIB group metal is 12-39% by weight, and the content of the VIII group metal is 1-9% by weight.

[0091] In one embodiment, the olefins in the olefin-rich stream are C5 or higher olefins; the content of C5 or higher olefins in the olefin-rich stream is 50 wt% or more, preferably 80 wt% or more.

[0092] In a specific embodiment, the olefin-containing logistics separated by the separation system can be further separated by the olefin separation system, thereby achieving the effect of concentrating the olefin-containing logistics, thereby increasing the olefin content in the olefin-containing logistics returned to the catalytic conversion reactor, and also increasing the yield and selectivity of light olefins.

[0093] See also Figure 1 In a first specific embodiment, the catalytic conversion method for producing light olefins comprises the following steps:

[0094] In the first reaction zone I, the pre-lifting medium enters from the bottom of the catalytic conversion reactor 2 through pipeline 1, and the regenerated catalytic conversion catalyst from pipeline 17 moves upward along the catalytic conversion reactor 2 under the lifting effect of the pre-lifting medium. The olefin-rich feedstock (olefin content ≥ 50%) is injected into the bottom of the first reaction zone I of the reactor 2 through pipeline 3 together with the atomized steam from pipeline 4, and contacts and reacts with the catalytic conversion catalyst at a temperature above 650° C., thereby obtaining a first mixed stream and continuing to move upward;

[0095] In the second reaction zone II, heavy crude oil is injected into the bottom of the second reaction zone II of the catalytic conversion reactor 2 together with atomized steam from pipeline 6 via pipeline 5, and an organic oxygen-containing compound raw material (such as methanol) is introduced into the bottom of the second reaction zone II via pipeline 7. The heavy crude oil and the organic oxygen-containing compound raw material respectively contact and react with the first mixed material flow from the first reaction zone I already in the catalytic conversion reactor 2.

[0096] The generated reaction products and the deactivated catalyst to be regenerated enter the cyclone separator in the settler 9 through the outlet section 8 to separate the catalyst to be regenerated from the reaction products. The reaction products enter the gas collecting chamber 10, and the catalyst fine powder returns to the settler from the feed leg. The catalyst to be regenerated in the settler flows to the stripping section 11 and contacts with the stripping steam from the pipeline 12. The oil and gas stripped from the catalyst to be regenerated enters the gas collecting chamber 10 after passing through the cyclone separator. The stripped catalyst to be regenerated enters the regenerator 14 through the inclined pipe 13, and the main air enters the regenerator through the pipeline 16 to burn off the coke on the catalyst to be regenerated, so as to regenerate the deactivated catalyst to be regenerated. The flue gas enters the smoke exhaust fan through the pipeline 15. The regenerated catalyst enters the riser through the pipeline 17.

[0097] The reaction product (reaction oil and gas) enters the subsequent product separation device 20 through the large oil and gas pipeline 19 for the first separation treatment, the separated hydrogen, methane and ethane are led out through the pipeline 21, ethylene is led out through the pipeline 22, propylene is led out through the pipeline 23, butene is led out through the pipeline 24, butene can be returned to the bottom of the first reaction zone I of the catalytic conversion reactor 2 or not to continue the reaction, propane and butane are led out through the pipeline 25, and the unconverted organic oxygen-containing compounds are led out through the pipeline 26, which can be returned to the bottom of the second reaction zone of the catalytic conversion reactor or not to continue the reaction; the first catalytic cracking distillate oil with an initial boiling point of any temperature greater than 20°C and less than 140°C is introduced into the olefin separation device 29 through the pipeline 27 for the third separation treatment, and the olefin-free stream, the small molecule olefin stream and the large molecule olefin stream are separated. Hydrocarbon stream: the olefin-free stream is led out through pipeline 31, the small molecular olefin stream is introduced as the olefin-rich stream into the bottom of the first reaction zone I of the catalytic conversion reactor through pipeline 30 for further reaction, and the large molecular olefin stream is returned to the bottom of the second reaction zone of the catalytic conversion reactor 2 through pipeline 34 for further reaction; the second catalytic cracking distillate oil with a final distillation point of any temperature less than 550°C and greater than 250°C is introduced into the hydrotreatment reactor 32 through pipeline 28 (the cut point between the first catalytic cracking distillate oil and the second catalytic cracking distillate oil is any temperature between 140-250°C), and light components and hydrocatalytic cracking second distillate oil are obtained after hydrotreatment: the light components are led out through pipeline 18, and the hydrocatalytic cracking second distillate oil is introduced into the bottom of the second reaction zone of the catalytic conversion reactor 2 through pipeline 33 for further reaction.

[0098] See also Figure 2In a second specific embodiment, the catalytic conversion method for preparing light olefins comprises the following steps:

[0099] In the first reaction zone I, the pre-lifting medium enters from the bottom of the catalytic conversion reactor 2 through pipeline 1, and the regenerated catalytic conversion catalyst from pipeline 17 moves upward along the catalytic conversion reactor 2 under the lifting effect of the pre-lifting medium. The olefin-rich feedstock (olefin content ≥ 50%) is injected into the bottom of the first reaction zone of the reactor 2 through pipeline 3 together with the atomized steam from pipeline 4, and contacts and reacts with the catalytic conversion catalyst at a temperature above 650° C., thereby obtaining a first mixed stream and continuing to move upward;

[0100] In the second reaction zone II, heavy crude oil is injected into the upstream of the second reaction zone of the catalytic conversion reactor 2 through pipeline 5 together with atomized steam from pipeline 6, so that the heavy crude oil contacts and reacts with the first mixed stream from the first reaction zone, and a second mixed stream is obtained and continues to move upward; an organic oxygen-containing compound feedstock (such as methanol) is introduced into the downstream of the second reaction zone through pipeline 7, so that the organic oxygen-containing compound feedstock contacts and reacts with the second mixed stream.

[0101] The generated reaction products and the deactivated catalyst to be regenerated enter the cyclone separator in the settler 9 through the outlet section 8 to separate the catalyst to be regenerated from the reaction products. The reaction products enter the gas collecting chamber 10, and the catalyst fine powder returns to the settler from the feed leg. The catalyst to be regenerated in the settler flows to the stripping section 11 and contacts with the stripping steam from the pipeline 12. The oil and gas stripped from the catalyst to be regenerated enters the gas collecting chamber 10 after passing through the cyclone separator. The stripped catalyst to be regenerated enters the regenerator 14 through the inclined pipe 13, and the main air enters the regenerator through the pipeline 16 to burn off the coke on the catalyst to be regenerated, so as to regenerate the deactivated catalyst to be regenerated. The flue gas enters the smoke exhaust fan through the pipeline 15. The regenerated catalyst enters the riser through the pipeline 17.

[0102] The reaction product (reaction oil and gas) enters the subsequent product separation device 20 through the large oil and gas pipeline 19 for the first separation treatment. The separated hydrogen, methane and ethane are led out through the pipeline 21, ethylene is led out through the pipeline 22, propylene is led out through the pipeline 23, butene is led out through the pipeline 24, butene can be returned to the bottom of the first reaction zone I of the catalytic conversion reactor 2 or not to continue the reaction, propane and butane are led out through the pipeline 25, and the unconverted organic oxygen-containing compounds are led out through the pipeline 26, which can be returned to the downstream of the second reaction zone of the catalytic conversion reactor or not to continue the reaction; the first catalytic cracking distillate oil with an initial boiling point of any temperature greater than 20°C and less than 140°C is introduced into the olefin separation device 29 through the pipeline 27 for the third separation treatment, and the olefin-free logistics, small molecular olefin logistics and large molecular olefin logistics are separated. Logistics: The olefin-free logistics is led out from pipeline 31, and the small molecular olefin logistics is introduced as the olefin-rich logistics into the bottom of the first reaction zone I of the catalytic conversion reactor through pipeline 30 for further reaction, and the large molecular olefin logistics is returned to the upstream of the second reaction zone of the catalytic conversion reactor 2 through pipeline 34 for further reaction; the second catalytic cracking distillate oil with a final distillation point of any temperature less than 550°C and greater than 250°C is introduced into the hydrotreatment reactor 32 through pipeline 28 (the cutting point between the first catalytic cracking distillate oil and the second catalytic cracking distillate oil is any temperature between 140-250°C), and light components and hydrocatalytic cracking second distillate oil are obtained after hydrotreatment: the light components are led out from pipeline 18, and the hydrocatalytic cracking second distillate oil is introduced into the upstream of the second reaction zone of the catalytic conversion reactor 2 through pipeline 33 for further reaction.

[0103] See also Figure 3 In a third specific embodiment, the catalytic conversion method for producing light olefins comprises the following steps:

[0104] In the first reaction zone I, the pre-lifting medium enters from the bottom of the catalytic conversion reactor 2 through pipeline 1, and the regenerated catalytic conversion catalyst from pipeline 17 moves upward along the catalytic conversion reactor 2 under the lifting effect of the pre-lifting medium. The olefin-rich feedstock (olefin content ≥ 50%) is injected into the bottom of the first reaction zone of the reactor 2 through pipeline 3 together with the atomized steam from pipeline 4, and contacts and reacts with the catalytic conversion catalyst at a temperature above 650° C., thereby obtaining a first mixed stream and continuing to move upward;

[0105] In the second reaction zone II, heavy crude oil is injected into the upstream of the second reaction zone of the catalytic conversion reactor 2 through pipeline 5 together with atomizing steam from pipeline 6, and contacts with the first mixed stream from the first reaction zone I already in the catalytic conversion reactor 2. The heavy crude oil reacts on the hot catalyst to obtain a second mixed stream and moves upward. Organic oxygen-containing compounds (such as methanol) are introduced into the downstream of the second reaction zone through pipeline 7, contact with and react with the second mixed stream from the upstream of the second reaction zone.

[0106] The generated reaction products and the deactivated catalyst to be regenerated enter the cyclone separator in the settler 9 through the outlet section 8 to separate the catalyst to be regenerated from the reaction products. The reaction products enter the gas collecting chamber 10, and the catalyst fine powder returns to the settler from the feed leg. The catalyst to be regenerated in the settler flows to the stripping section 11 and contacts with the stripping steam from the pipeline 12. The oil and gas stripped from the catalyst to be regenerated enters the gas collecting chamber 10 after passing through the cyclone separator. The stripped catalyst to be regenerated enters the regenerator 14 through the inclined pipe 13, and the main air enters the regenerator through the pipeline 16 to burn off the coke on the catalyst to be regenerated, so as to regenerate the deactivated catalyst to be regenerated. The flue gas enters the smoke exhaust fan through the pipeline 15. The regenerated catalyst enters the riser through the pipeline 17.

[0107] The reaction product (reaction oil and gas) enters the subsequent product separation device 20 through the large oil and gas pipeline 19 for the first separation treatment, the separated hydrogen, methane and ethane are led out through the pipeline 21, ethylene is led out through the pipeline 22, propylene is led out through the pipeline 23, butene is led out through the pipeline 24, butene can be returned to the bottom of the first reaction zone I of the catalytic conversion reactor 2 or not to continue the reaction, propane and butane are led out through the pipeline 25, the separated unconverted organic oxygen-containing compounds are led out through the pipeline 26, and can be returned to the downstream of the second reaction zone of the catalytic conversion reactor 2 or not to continue the reaction; the first catalytic cracking distillate oil with an initial boiling point of any temperature greater than 20°C and less than 140°C is introduced into the olefin separation device 29 through the pipeline 27 for the second Separation treatment is performed to obtain a logistics containing no olefins and a logistics rich in olefins: the logistics containing no olefins is drawn out through pipeline 31, and the logistics rich in olefins is introduced into the bottom of the first reaction zone I of the catalytic conversion reactor through pipeline 30 for continued reaction; the second catalytic cracking distillate oil with a final distillation point of any temperature less than 550°C and greater than 250°C is introduced into the hydrotreatment reactor 32 through pipeline 28 (the cut point between the first catalytic cracking distillate oil and the second catalytic cracking distillate oil is any temperature between 140-250°C), and after hydrogenation treatment, a light component and a hydrocatalytic cracking second distillate oil are obtained: the light component is drawn out through pipeline 18, and the hydrocatalytic cracking second distillate oil is introduced into the upstream of the second reaction zone of the catalytic conversion reactor 2 through pipeline 33 for continued reaction.

[0108] See also Figure 4 In a fourth specific embodiment, the catalytic conversion method for producing light olefins comprises the following steps:

[0109] In the first reaction zone I, the pre-lifting medium enters from the bottom of the catalytic conversion reactor 2 via pipeline 1, and the regenerated catalytic conversion catalyst from pipeline 17 is accelerated upward along the catalytic conversion reactor 2 under the lifting effect of the pre-lifting medium. The olefin-rich feedstock (olefin content ≥ 50%) is injected into the bottom of the first reaction zone of the reactor 2 via pipeline 3 together with the atomized steam from pipeline 4, and contacts and reacts with the catalytic conversion catalyst at a temperature above 650° C., thereby obtaining a first mixed stream and continuing to move upward;

[0110] In the second reaction zone II, heavy crude oil is injected into the bottom of the second reaction zone II of the catalytic conversion reactor 2 through pipeline 5 together with atomizing steam from pipeline 6, and organic oxygen-containing compound raw material (such as methanol) enters the bottom of the second reaction zone II through pipeline 7 together with the heavy crude oil, and contacts and reacts with the first mixed material flow from the first reaction zone I.

[0111] The generated reaction flow and the deactivated catalyst to be regenerated enter the cyclone separator in the settler 9 through the outlet section 8 to separate the catalyst to be regenerated from the reaction flow. The reaction flow enters the gas collecting chamber 10, and the catalyst fine powder returns to the settler from the feed leg. The catalyst to be regenerated in the settler flows to the stripping section 11 and contacts with the stripping steam from the pipeline 12. The oil and gas stripped from the catalyst to be regenerated enters the gas collecting chamber 10 after passing through the cyclone separator. The stripped catalyst to be regenerated enters the regenerator 14 through the inclined pipe 13, and the main air enters the regenerator through the pipeline 16 to burn off the coke on the catalyst to be regenerated, so as to regenerate the deactivated catalyst to be regenerated. The flue gas enters the smoke exhaust fan through the pipeline 15. The regenerated catalyst enters the riser through the pipeline 17.

[0112] The reaction product (reaction oil and gas) enters the subsequent separation device 20 through the large oil and gas pipeline 19 for the first separation treatment. The separated hydrogen, methane and ethane are led out through the pipeline 21, ethylene is led out through the pipeline 22, propylene is led out through the pipeline 23, butene is led out through the pipeline 24, butene can be returned to the bottom of the first reaction zone I of the catalytic conversion reactor 2 or not to continue the reaction, propane and butane are led out through the pipeline 25, and the unconverted organic oxygen-containing compounds are led out through the pipeline 26, which can be returned to the bottom of the second reaction zone II of the catalytic conversion reactor 2 or not to continue the reaction; the first catalytic cracking distillate oil with an initial boiling point of any temperature greater than 20°C and less than 140°C is introduced into the olefin separation device 29 through the pipeline 27 for the second separation treatment, Separate to obtain an olefin-free stream and an olefin-rich stream: the olefin-free stream is drawn out through pipeline 31, and the olefin-rich stream is introduced into the bottom of the first reaction zone I of the catalytic conversion reactor 2 through pipeline 30 for continued reaction; the second catalytic cracking distillate oil with a final distillation point of any temperature less than 550°C and greater than 250°C is introduced into a hydroprocessing reactor 32 through pipeline 28 (the cut point between the first catalytic cracking distillate oil and the second catalytic cracking distillate oil is any temperature between 140-250°C); after hydroprocessing, a light component and a hydrogenated second catalytic cracking distillate oil are obtained: the light component is drawn out through pipeline 18, and the hydrogenated second catalytic cracking distillate oil is introduced into the bottom of the second reaction zone II of the catalytic conversion reactor 2 through pipeline 33 for continued reaction.

[0113] The Disclosure Figure 1-Figure 4 In the figure, the dotted line represents that the component may be returned to the catalytic conversion reactor to continue the reaction or may not be returned to the catalytic conversion reactor.

[0114] The present disclosure is further described in detail by way of examples. The raw materials used in the examples can all be obtained through commercial sources.

[0115] (1) The raw materials I and II used in the examples of the present disclosure are heavy raw oils (heavy oils I and II), and their properties are shown in Tables 1-1 and 1-2 below.

[0116] Table 1-1 (Heavy Oil I)

[0117]

[0118] Table 1-2 (Heavy Oil II)

[0119]

[0120]

[0121] (2) The catalyst i used in the present disclosure is prepared by the following preparation method:

[0122] 969 g of kaolinite (product of China Kaolin Company, solid content 73%) was slurried with 4300 g of decationized water, and then 781 g of pseudo-boehmite (product of Shandong Zibo aluminum stone factory, solid content 64%) and 144 ml of hydrochloric acid (concentration 30%, specific gravity 1.56) were added and stirred evenly, and aged at 60 ° C for 1 hour, keeping the pH at 2-4, and then cooled to room temperature, and then 5000 g of slurry prepared in advance was added, including 1600 g of medium-pore ZSM-5 molecular sieve and large-pore Y-type molecular sieve (produced by Sinopec Catalyst Qilu Branch), with a weight ratio of 9:1. Stir evenly, spray dry, and wash away free Na + The catalyst was aged at 800°C and 100% water vapor. The aged catalyst is called catalyst i. The properties of catalyst i are shown in Table 2.

[0123] (3) The catalyst ii used in the present disclosure has a trade name of CEP-1, which is an industrial product produced by Sinopec Catalyst Qilu Branch. The catalyst properties are shown in Table 2.

[0124] (4) The catalyst iii used in the present disclosure has a trade name of CHP-1, which is an industrial product produced by Sinopec Catalyst Qilu Branch. The catalyst properties are shown in Table 2.

[0125] The properties of the above catalysts i-iii are shown in Table 2 below:

[0126] Table 2

[0127]

[0128]

[0129] (4) The catalyst iv used in the present disclosure is prepared by the following preparation method:

[0130] Weigh ammonium metatungstate ((NH4)2W4O 13 ·18H2O, chemically pure) and nickel nitrate (Ni(NO3)2·18H2O, chemically pure) were prepared into 200 ml solution with water. The solution was added to 50 g of alumina support and impregnated for 3 hours at room temperature. During the impregnation process, the impregnation solution was treated with ultrasound for 30 minutes, cooled, filtered, and dried in a microwave oven for about 15 minutes. The composition of the catalyst ⅳ was: 30.0 wt% WO3, 3.1 wt% NiO and the balance alumina.

[0131] (5) The catalyst V used in the present disclosure is prepared by the following preparation method:

[0132] Weigh 1000 g of pseudo-boehmite produced by Sinopec Catalyst Changling Branch, then add 1000 ml of an aqueous solution containing 10 ml of nitric acid (chemically pure), extrude into strips on a twin-screw extruder, dry at 120°C for 4 hours, and calcine at 800°C for 4 hours to obtain a catalyst carrier. The catalyst was immersed in 900 ml of an aqueous solution containing 120 g of ammonium fluoride for 2 hours, dried at 120° C. for 3 hours, and calcined at 600° C. for 3 hours; after cooling to room temperature, immersed in 950 ml of an aqueous solution containing 133 g of ammonium metamolybdate for 3 hours, dried at 120° C. for 3 hours, and calcined at 600° C. for 3 hours; after cooling to room temperature, immersed in 900 ml of an aqueous solution containing 180 g of nickel nitrate and 320 g of ammonium metatungstate for 4 hours; the fluorine-containing alumina carrier was immersed in a mixed aqueous solution of 0.1 wt % of ammonium metamolybdate (chemically pure) relative to the catalyst carrier and 0.1 wt % of nickel nitrate (chemically pure) relative to the catalyst carrier for 4 hours, dried at 120° C. for 3 hours, and calcined at 600° C. for 4 hours to obtain Catalyst V.

[0133] Example 1

[0134] See also Figure 3 The process shown was tested on a pilot scale unit with a riser reactor.

[0135] The 1-pentene and the high temperature (≥650°C) catalytic conversion catalyst i are contacted at the bottom of the first reaction zone, and a catalytic conversion reaction is carried out under the conditions of a reaction temperature of 700°C, a reaction pressure of 0.1 MPa, a reaction time of 5 seconds, and a weight ratio of the catalytic conversion catalyst i to the 1-pentene of 40:1;

[0136] The heavy oil I is contacted with the first mixed stream from the first reaction zone upstream of the second reaction zone to obtain a second reaction stream. The reaction temperature upstream of the second reaction zone is 530°C, the reaction pressure is 0.1 MPa, the reaction time is 6 seconds, and the weight ratio of the catalytic conversion catalyst I to the heavy oil I is 5:1.

[0137] Methanol is contacted with the second reaction stream downstream of the second reaction zone to obtain reaction oil gas and a catalyst to be generated. The reaction temperature downstream of the second reaction zone is 500°C, the reaction pressure is 0.1 MPa, the reaction time is 3 seconds, the weight ratio of catalytic conversion catalyst I to methanol is 40:1, and the weight ratio of 1-pentene, heavy oil I to methanol is 1:8:1.

[0138] The reaction products and the catalyst to be regenerated of the separation reaction are introduced into a regenerator together for charring and regeneration. The reaction products are introduced into a combined separation system together, and a first separation treatment is first performed to obtain products including ethylene, propylene, butene, unconverted methanol, a first catalytic cracking distillate oil (initial distillation point 35°C, final distillation point 180°C) and a second catalytic cracking distillate oil (initial distillation point 180°C, final distillation point 510°C) and other components; then the first catalytic cracking distillate oil is subjected to a second separation treatment to separate a stream rich in olefins, and the second catalytic cracking distillate oil and a hydrogenation catalyst IV are heated at 350°C, a hydrogen partial pressure of 18 MPa, and a volume space velocity of 1.5 hours. -1 , and the hydrogenated second catalytic cracking distillate oil is obtained by reaction under the condition of hydrogen-to-oil volume ratio of 1500.

[0139] The separated olefin-rich stream (containing 80% by weight of C5 and above olefins) was introduced into the bottom of the first reaction zone for re-cracking, the reaction temperature was 700°C, and the reaction time was 5 seconds; the hydrogenated second catalytic cracking distillate oil was mixed with heavy oil I, and then returned to the upstream of the second reaction zone for further reaction. The reaction conditions and product distribution are listed in Table 3.

[0140] Comparative Example 1

[0141] See also Figure 3 The process shown was tested on a pilot scale unit with a riser reactor.

[0142] A reaction process similar to that of Example 1 was used to conduct the test on a medium-sized device of a riser reactor. The difference is that the reaction raw materials do not contain 1-pentene and methanol, and the olefin-rich logistics do not return to the device. The heavy oil I and the catalytic conversion catalyst i are contacted at the bottom of the second reaction zone, and a catalytic conversion reaction occurs at a reaction temperature of 530°C, a reaction pressure of 0.1MPa, a reaction time of 6 seconds, and a weight ratio of catalytic conversion catalyst i to heavy oil I of 5:1. The reaction product of the separation reaction and the catalyst to be regenerated are introduced together into the regenerator for charring and regeneration, and the reaction product is introduced together into the combined separation system, and the first separation treatment is first performed to obtain products including ethylene, propylene, butene, the first catalytic cracking distillate oil (initial boiling point 35°C, final boiling point 180°C) and the second catalytic cracking distillate oil (initial boiling point 180°C, final boiling point 510°C) and other components. Then the second catalytic cracking distillate oil and the hydrogenation catalyst iv are heated at 350°C, a hydrogen partial pressure of 18MPa, and a volume space velocity of 1.5 hours. -1 , the hydrogen-oil volume ratio was 1500 to obtain the hydrogenated second catalytic cracking distillate oil. The obtained hydrogenated second catalytic cracking distillate oil was mixed with heavy oil I and then returned to the upstream of the second reaction zone for reaction. The reaction conditions and product distribution are listed in Table 3.

[0143] Example 2

[0144] See also Figure 3 The process shown was tested on a pilot plant of a riser reactor. A reaction process similar to that of Example 1 was used, except that no 1-pentene was added.

[0145] The heavy oil I and the catalytic conversion catalyst i are contacted upstream of the second reaction zone, and a catalytic conversion reaction is carried out at a reaction temperature of 530°C, a reaction pressure of 0.1 MPa, a reaction time of 6 seconds, and a weight ratio of the catalytic conversion catalyst i to the heavy oil I of 5:1 to obtain a second reaction stream. Methanol is contacted with the second reaction stream downstream of the second reaction zone, and a catalytic conversion reaction is carried out at a reaction temperature of 500°C, a reaction pressure of 0.1 MPa, a reaction time of 3 seconds, and a weight ratio of the catalytic conversion catalyst i to methanol of 40:1, and the weight ratio of the heavy oil I to the methanol is 8:1.

[0146] The reaction products and the catalyst to be regenerated of the separation reaction are introduced into a regenerator together for charring and regeneration. The reaction products are introduced into a combined separation system together, and a first separation treatment is first performed to obtain products including ethylene, propylene, butene, unconverted methanol, a first catalytic cracking distillate oil (initial distillation point 35°C, final distillation point 180°C) and a second catalytic cracking distillate oil (initial distillation point 180°C, final distillation point 510°C) and other components; then the first catalytic cracking distillate oil is subjected to a second separation treatment to separate a stream rich in olefins, and the second catalytic cracking distillate oil and a hydrogenation catalyst IV are heated at 350°C, a hydrogen partial pressure of 18 MPa, and a volume space velocity of 1.5 hours. -1 , and the hydrogenated second catalytic cracking distillate oil is obtained by reaction under the condition of hydrogen-to-oil volume ratio of 1500.

[0147] The unconverted methanol obtained by separation is introduced into the downstream of the second reaction zone for further reaction; the olefin-rich stream obtained by separation (containing 80% by weight of C5 or higher olefins) is introduced into the bottom of the first reaction zone for further cracking, the reaction temperature is 700°C, and the reaction time is 5 seconds; the hydrogenated second catalytic cracking distillate oil is mixed with heavy oil I, and then returned to the upstream of the second reaction zone for further reaction. The reaction conditions and product distribution are listed in Table 3.

[0148] Comparative Example 2

[0149] The test was conducted on a medium-sized device of a riser reactor. Heavy oil I and catalytic conversion catalyst II were in contact at the bottom of the riser. The catalytic conversion reaction occurred at a reaction temperature of 610°C, a weight ratio of catalytic conversion catalyst II to heavy oil I of 16.9:1, a reaction pressure of 0.1 MPa, and a reaction time of 6 seconds. The product was not subjected to hydrogenation treatment and continued to react. The reaction conditions and product distribution are listed in Table 3.

[0150] Example 3

[0151] The second catalytic cracking fraction obtained by the first separation treatment (initial boiling point 180°C, final boiling point 510°C) was not subjected to deep hydrogenation treatment, but was contacted with a hydrodesulfurization catalyst V in a hydrodesulfurization reactor at a reaction pressure of 6.0 MPa, a reaction temperature of 350°C, a hydrogen-to-oil volume ratio of 350, and a volume space velocity of 2.0 h / min. -1 The reaction is carried out to obtain a low-sulfur hydrogenated second catalytic cracking distillate oil, which is mixed with heavy oil II and returned to the upstream of the second reaction zone for further reaction. The reaction conditions and product distribution are listed in Table 3.

[0152] Comparative Example 3

[0153] The test was conducted on a medium-sized device of a riser reactor, where heavy oil II and catalytic conversion catalyst III contacted at the bottom of the riser, and catalytic conversion reaction occurred at a reaction temperature of 530°C, a weight ratio of catalytic conversion catalyst III to heavy oil II of 5:1, a reaction pressure of 0.1 MPa, and a reaction time of 6 seconds, and the hydrodesulfurization treatment was basically the same as in Example 3. The reaction conditions and product distribution are listed in Table 3.

[0154] Example 4

[0155] See also Figure 1 The process shown was tested on a pilot scale unit with a riser reactor.

[0156] The 1-pentene and the high temperature (≥650°C) catalytic conversion catalyst i are contacted at the bottom of the first reaction zone, and a catalytic conversion reaction is carried out under the conditions of a reaction temperature of 600°C, a reaction pressure of 0.1 MPa, a reaction time of 5 seconds, and a weight ratio of the catalytic conversion catalyst i to the 1-pentene of 40:1;

[0157] The heavy oil I and methanol are contacted with the first mixed stream from the first reaction zone at the bottom of the second reaction zone, and the heavy oil I and methanol are reacted with the catalytic conversion catalyst i at a reaction temperature of 530°C, a reaction pressure of 0.1 MPa, a reaction time of 6 seconds, a weight ratio of the catalytic conversion catalyst i to the heavy oil I of 5:1, and a weight ratio of the catalyst to the methanol of 40:1 to undergo a catalytic conversion reaction. The weight ratio of the heavy oil I to the methanol is 8:1.

[0158] The reaction products and the catalyst to be regenerated of the separation reaction are introduced into a regenerator for charring and regeneration. The reaction products are introduced into a combined separation system. A first separation treatment is first performed to obtain products including ethylene, propylene, butene, unconverted methanol, a first catalytic cracking distillate oil (initial distillation point 35°C, final distillation point 300°C) and a second catalytic cracking distillate oil (initial distillation point 300°C, final distillation point 510°C) and other components; then the first catalytic cracking distillate oil is subjected to a third separation treatment to separate a small molecular olefin stream (initial distillation point 35°C, final distillation point 160°C) and a large molecular olefin stream (initial distillation point 160°C, final distillation point 300°C), and the second catalytic cracking distillate oil and a hydrogenation catalyst IV are heated at 350°C, a hydrogen partial pressure of 18 MPa, and a volume space velocity of 1.5 hours. -1 , and hydrogenation treatment is carried out under the condition of a hydrogen-to-oil volume ratio of 1500 to obtain a hydrogenated second catalytic cracking distillate oil.

[0159] The separated small molecule olefin stream (containing 80 wt% of C5-C9 olefins) is introduced into the bottom of the first reaction zone for further cracking, the reaction temperature is 600°C, and the reaction time is 5 seconds; the separated large molecule olefin stream (containing 80 wt% of C10-C18 olefins) is mixed with the unconverted methanol and then returned to the bottom of the second reaction zone for further reaction; the hydrogenated second catalytic cracking distillate oil is mixed with heavy oil I and then introduced into the bottom of the second reaction zone of the catalytic conversion reactor for further reaction. The reaction conditions and product distribution are listed in Table 3.

[0160] Example 5

[0161] See also Figure 2 The process shown was tested on a pilot scale unit with a riser reactor.

[0162] The 1-pentene and the high temperature (≥650°C) catalytic conversion catalyst i are contacted at the bottom of the first reaction zone, and the catalytic conversion reaction occurs under the conditions of a reaction temperature of 700°C, a reaction pressure of 0.1 MPa, a reaction time of 5 seconds, and a weight ratio of the catalyst to the 1-pentene of 40:1;

[0163] The heavy oil I is contacted with the first mixed stream from the first reaction zone upstream of the second reaction zone, and the heavy oil I and the catalytic conversion catalyst i undergo a catalytic conversion reaction under the conditions of a reaction temperature of 530°C, a reaction pressure of 0.1 MPa, a reaction time of 6 seconds, and a weight ratio of the catalyst to the heavy oil I of 5:1 to obtain a second mixed stream.

[0164] Methanol is contacted with the second mixed stream downstream of the second reaction zone, and a catalytic conversion reaction is carried out with the catalytic conversion catalyst i at a reaction temperature of 500°C, a reaction pressure of 0.1 MPa, a reaction time of 3 seconds, and a weight ratio of the catalytic conversion catalyst i to methanol of 40:1. The weight ratio of 1-pentene, heavy oil I and methanol is 1:8:1.

[0165] The reaction products and the catalyst to be regenerated of the separation reaction are introduced into a regenerator for charring and regeneration. The reaction products are introduced into a combined separation system. A first separation treatment is first performed to obtain products including ethylene, propylene, butene, unconverted methanol, a first catalytic cracking distillate oil (initial distillation point 35°C, final distillation point 300°C) and a second catalytic cracking distillate oil (initial distillation point 300°C, final distillation point 510°C) and the like; then the first catalytic cracking distillate oil is subjected to a third separation treatment to separate a small molecular olefin stream (initial distillation point 35°C, final distillation point 160°C) and a large molecular olefin stream (initial distillation point 160°C, final distillation point 300°C); the second catalytic cracking distillate oil and a hydrogenation catalyst IV are heated at 350°C, a hydrogen partial pressure of 18 MPa, and a volume space velocity of 1.5 hours. -1 , and hydrogenation treatment is carried out under the condition of a hydrogen-to-oil volume ratio of 1500 to obtain a hydrogenated second catalytic cracking distillate oil.

[0166] The separated small molecule olefin stream (containing 80 wt% of C5-C9 olefins) is introduced into the bottom of the first reaction zone for re-cracking, the reaction temperature is 700°C, and the reaction time is 5 seconds; the separated unconverted methanol is returned to the downstream of the second reaction zone for further reaction; the large molecule olefin stream (containing 80 wt% of C10-C18 olefins) is returned to the upstream of the second reaction zone for further reaction; the hydrogenated second catalytic cracking distillate oil is mixed with heavy oil I and then returned to the upstream of the second reaction zone for further reaction. The reaction conditions and product distribution are listed in Table 3.

[0167] Table 3

[0168]

[0169] It can be seen from Table 3 that compared with comparative examples 1-3, the catalytic conversion methods provided in Examples 1-5 of the present application have higher yields of ethylene, propylene and butene, and the total yield of the three olefins can reach more than 60%; and the higher the olefin content of the raw material, the better the effect. When 1-pentene with 100% olefin content is used as the olefin-rich raw material, the ethylene content of the product obtained in Example 1 is 15.31%, the propylene content is 29.26%, and the butene content is 22.00%. The total content of the three is as high as 66.57%.

[0170] Furthermore, when using Figure 2According to the catalytic conversion method shown, the product obtained in Example 5 has an ethylene content of 17.48%, a propylene content of 31.66%, and a butene content of 19.96%, and the total content of the three is as high as 69.10%.

[0171] Example 6

[0172] See also Figure 4 The process shown was tested on a pilot scale unit with a riser reactor.

[0173] The heavy oil I and methanol are contacted with the first mixed stream from the first reaction zone at the bottom of the second reaction zone, and the heavy oil I and methanol are reacted with the catalytic conversion catalyst i at a reaction temperature of 530°C, a reaction pressure of 0.1 MPa, a reaction time of 4 seconds, a weight ratio of the catalytic conversion catalyst i to the heavy oil I of 5:1, and a weight ratio of the catalytic conversion catalyst i to the methanol of 40:1 to cause a catalytic conversion reaction. The weight ratio of the heavy oil I to the methanol is 8:1.

[0174] The reaction product and the catalyst to be regenerated of the separation reaction are introduced into a regenerator together for charring and regeneration; the reaction product is introduced into a combined separation system together, and a first separation treatment is first performed to obtain products including ethylene, propylene, butene, unconverted methanol, a first catalytic cracking distillate oil (initial distillation point 35°C, final distillation point 180°C) and a second catalytic cracking distillate oil (initial distillation point 180°C, final distillation point 510°C) and other components; the first catalytic cracking distillate oil is then introduced into an olefin separation device for a second separation treatment to separate a stream rich in olefins; the second catalytic cracking distillate oil and a hydrogenation catalyst IV are heated at 350°C, a hydrogen partial pressure of 18 MPa, and a volume space velocity of 1.5 hours. -1 , and hydrogenation treatment is carried out under the condition of a hydrogen-to-oil volume ratio of 1500 to obtain a hydrogenated second catalytic cracking distillate oil.

[0175] The separated olefin-rich stream (containing 80% by weight of C5 or higher olefins) is introduced into the bottom of the first reaction zone for re-cracking, the reaction temperature is 700°C, and the reaction time is 5 seconds; the hydrogenated second catalytic cracking distillate is mixed with heavy oil I, and then returned to the bottom of the second reaction zone for further reaction. The separated butene is introduced into the bottom of the first reaction zone for re-cracking (along the material flow direction, the introduction position of butene is located upstream of the introduction position of the olefin-rich stream), the reaction temperature is 650°C, the weight ratio of catalyst i to butene is 100:1, and the reaction time is 0.2s.

[0176] In the product obtained in this example, the ethylene yield is 24.44%, the propylene yield is 31.87%, and the hydrogen+methane+ethane yield is only 3.91%, which further increases the ethylene and propylene yields.

[0177] The preferred embodiments of the present disclosure are described in detail above; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0178] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0179] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A catalytic conversion method for preparing light olefins, the method comprising the following steps: (1) contacting an olefin-rich feedstock with a catalytic conversion catalyst at a temperature of 650° C. or higher in a first reaction zone of a catalytic conversion reactor under first catalytic conversion reaction conditions and performing a first catalytic conversion reaction to obtain a first mixed stream; the olefin-rich feedstock contains more than 50% by weight of olefins; The olefin-rich raw material is at least one of a C5+ fraction produced by an alkane dehydrogenation unit, a C5+ fraction produced by a catalytic cracking unit of an oil refinery, a C5+ fraction produced by a steam cracking unit of an ethylene plant, a C5+ olefin-rich fraction produced as a by-product of MTO, and a C5+ olefin-rich fraction produced as a by-product of MTP; the alkane raw material of the alkane dehydrogenation unit is at least one of naphtha, aromatic raffinate and other light hydrocarbons; the conditions of the first catalytic conversion reaction include: The reaction temperature is 600-800°C, the reaction pressure is 0.05-1MPa, the reaction time is 0.01-100 seconds, and the weight ratio of the catalytic conversion catalyst to the olefin-rich raw material is (1-200): 1; Based on the total weight of the catalytic conversion catalyst, the catalytic conversion catalyst comprises 1-50 wt% of a molecular sieve, 5-99 wt% of an inorganic oxide and 0-70 wt% of clay; the molecular sieve comprises one or more of a large-pore molecular sieve, a medium-pore molecular sieve and a small-pore molecular sieve; based on the total weight of the catalytic conversion catalyst, the catalytic conversion catalyst further comprises 0.1 wt%-3 wt% of a metal ion, and the metal ion is selected from one or more of a Group VIII metal, a Group IVA metal and a rare earth metal; (2) under the second catalytic conversion reaction conditions, the heavy feedstock and the organic oxygen-containing compound feedstock are contacted with the first mixed stream from the first reaction zone in the second reaction zone of the catalytic conversion reactor and subjected to a second catalytic conversion reaction to obtain reaction oil gas and a catalyst to be produced; wherein the heavy feedstock is selected from petroleum hydrocarbons and / or mineral oils; the petroleum hydrocarbons are selected from one or more of vacuum gas oil, atmospheric gas oil, coking gas oil, deasphalted oil, vacuum residue oil, atmospheric residue oil and heavy aromatic raffinate oil; the mineral oil is selected from one or more of coal liquefaction oil, oil sand oil and shale oil; the The organic oxygen-containing compound raw material comprises at least one of methanol, ethanol, dimethyl ether, methyl ethyl ether and ethyl ether; the conditions of the second catalytic conversion reaction include: a reaction temperature of 300-650°C, a reaction pressure of 0.01-1MPa, a reaction time of 0.01-100 seconds, a weight ratio of the catalytic conversion catalyst to the heavy raw material of (1-100): 1; a weight ratio of the catalytic conversion catalyst to the organic oxygen-containing compound raw material of (1-100): 1; the reaction temperature of the first catalytic conversion reaction is 30-380°C higher than the reaction temperature of the second catalytic conversion reaction; (3) subjecting the reaction oil gas to a first separation treatment to separate ethylene, propylene, butene, organic oxygen-containing compounds, a first catalytic cracking distillate oil and a second catalytic cracking distillate oil; the initial distillation point of the first catalytic cracking distillate oil is any temperature greater than 20° C. and less than 140° C., the final distillation point of the second catalytic cracking distillate oil is any temperature less than 550° C. and greater than 250° C., and the cut point between the first catalytic cracking distillate oil and the second catalytic cracking distillate oil is any temperature between 140° C. and 250° C.; subjecting the first catalytic cracking fraction to a second separation treatment to separate an olefin-rich stream; (4) returning the olefin-rich stream to the catalytic conversion reactor for further reaction, wherein the olefins in the olefin-rich stream are C5 or higher olefins; and the content of C5 or higher olefins in the olefin-rich stream is 50 wt % or more; The method further comprises: contacting the second catalytic cracking distillate with a hydrogenation catalyst under hydrogenation reaction conditions to obtain a hydrogenated second catalytic cracking distillate, and returning the hydrogenated second catalytic cracking distillate to the catalytic conversion reactor for further reaction; The hydrogenation reaction conditions include: hydrogen partial pressure of 3.0-20.0 MPa, reaction temperature of 300-450°C, hydrogen-oil volume ratio of 300-2000, volume space velocity of 0.1-3.0 h -1 , based on the total weight of the hydrogenation catalyst, the hydrogenation catalyst comprises 20-90 wt % of a carrier, 10-80 wt % of a supported metal and 0-10 wt % of an additive; wherein the carrier is alumina and / or amorphous silica-alumina, the additive is selected from at least one of fluorine, phosphorus, titanium and platinum, and the supported metal is a VIB group metal and / or a VIII group metal.

2. The method according to claim 1, wherein: The method comprises: allowing the reaction oil gas to enter a product fractionation device for a first separation treatment to separate ethylene, propylene, butene, the organic oxygen-containing compound, the first catalytic cracking distillate oil and the second catalytic cracking distillate oil; allowing the first catalytic cracking fraction oil to enter an olefin separation unit for a second separation treatment to separate the olefin-rich stream; The olefin-rich stream is returned to the first reaction zone of the catalytic conversion reactor to continue the reaction.

3. The method according to claim 1, wherein: The method comprises: allowing the reaction oil gas to enter a product fractionation device for a first separation treatment to separate ethylene, propylene, butene, the organic oxygen-containing compound, the first catalytic cracking distillate oil and the second catalytic cracking distillate oil; The first catalytic cracking fraction oil enters an olefin separation unit for a third separation treatment to separate a large molecular olefin stream and a small molecular olefin stream; The small molecule olefin stream is returned as the olefin-rich stream to the first reaction zone of the catalytic conversion reactor for further reaction; and the large molecule olefin stream is returned to the second reaction zone of the catalytic conversion reactor for further reaction.

4. The method according to claim 1 or 3, wherein: The method further comprises: returning the separated butene to the first reaction zone of the catalytic conversion reactor for further reaction.

5. The method according to claim 4, wherein: The method further comprises: the butene returned to the catalytic conversion reactor for further reaction contacts the catalytic conversion catalyst before the olefin-rich stream.

6. The method according to claim 4, wherein: The reaction conditions for returning the butene to the catalytic reactor for continued reaction include: reaction temperature of 650-800°C, reaction pressure of 0.05-1MPa, reaction time of 0.01-10 seconds, and a weight ratio of the catalytic conversion catalyst to the returned butene of (20-200):

1.

7. The method according to claim 6, wherein: The reaction conditions for returning the butene to the catalytic reactor for continued reaction include: a reaction temperature of 680-780°C, a reaction pressure of 0.1-0.8MPa, a reaction time of 0.05-8 seconds, and a weight ratio of the catalytic conversion catalyst to the returned butene of (30-180):

1.

8. The method according to claim 1, wherein: The first catalytic conversion reaction conditions include: reaction temperature of 630-780° C.; reaction pressure of 0.1-0.8 MPa; reaction time of 0.1-80 seconds; and a weight ratio of the catalytic conversion catalyst to the olefin-rich raw material of (3-180):

1.

9. The method according to claim 1, wherein: The second catalytic conversion reaction conditions include: reaction temperature of 400-600°C; reaction pressure of 0.05-1MPa; reaction time of 0.1-80 seconds; weight ratio of the catalytic conversion catalyst to the heavy raw material of (3-70):1; weight ratio of the catalytic conversion catalyst to the organic oxygen-containing compound raw material of (3-50):

1.

10. The method according to claim 1, wherein: Taking the feeding position of the organic oxygen-containing compound raw material as the boundary, the second reaction zone is divided into a second reaction zone upstream and a second reaction zone downstream according to the flow direction of the reactants, and the second reaction zone downstream is located after the feeding position of the organic oxygen-containing compound raw material; The method further includes: The first mixed stream from the first reaction zone is brought into contact with the heavy feedstock upstream of the second reaction zone and subjected to a catalytic conversion reaction to obtain a second mixed stream; and then the second mixed stream is brought into contact with the organic oxygen-containing compound feedstock downstream of the second reaction zone and subjected to a catalytic conversion reaction to obtain the reaction oil gas and the catalyst to be generated.

11. The method according to claim 10, wherein: The catalytic conversion reaction conditions of the heavy feedstock and the first mixed stream in the upstream of the second reaction zone include: The reaction temperature is 400-650°C; the reaction pressure is 0.05-1MPa; the reaction time is 0.01-100 seconds; the weight ratio of the catalytic conversion catalyst to the heavy raw material is (1-100): 1; The catalytic conversion reaction conditions of the organic oxygen-containing compound feedstock and the second mixed stream in the downstream of the second reaction zone include: The reaction temperature is 300-550°C; the reaction pressure is 0.01-1MPa; the reaction time is 0.01-100 seconds; The reaction temperature in the upstream of the second reaction zone is 0-200° C. higher than the reaction temperature in the downstream of the second reaction zone; The weight ratio of the catalytic conversion catalyst to the organic oxygen-containing compound raw material is (1-100):

1.

12. The method according to claim 11, wherein: The catalytic conversion reaction conditions of the heavy feedstock and the first mixed stream in the upstream of the second reaction zone include: The reaction temperature is 450-600°C; the reaction pressure is 0.1-0.8MPa; the reaction time is 0.1-80 seconds; The weight ratio of the catalytic conversion catalyst to the heavy raw material is (3-70): 1; The catalytic conversion reaction conditions of the organic oxygen-containing compound feedstock and the second mixed stream in the downstream of the second reaction zone include: The reaction temperature is 400-530°C; the reaction pressure is 0.05-1MPa; the reaction time is 0.1-80 seconds; The reaction temperature in the upstream of the second reaction zone is 10-190° C. higher than the reaction temperature in the downstream of the second reaction zone; The weight ratio of the catalytic conversion catalyst to the organic oxygen-containing compound raw material is (3-50):

1.

13. The method according to claim 1, wherein: The method further comprises: returning the separated organic oxygen-containing compound to the second reaction zone of the catalytic conversion reactor for further reaction.

14. The method according to claim 1, wherein: The catalytic conversion reactor is a riser reactor.

15. The method according to claim 14, wherein: The catalytic conversion reactor is a variable diameter riser reactor.

16. The method according to claim 1, wherein: The method further comprises: regenerating the spent catalyst by burning it to obtain a regenerated catalyst; and returning the regenerated catalyst as the catalytic conversion catalyst to the first reaction zone of the catalytic conversion reactor.

17. The method according to claim 1, wherein: The olefin content in the olefin-rich feedstock is greater than 80% by weight.

18. The method according to claim 17, wherein: The olefin content in the olefin-rich feedstock is greater than 90% by weight.

19. The method according to claim 18, wherein: The olefin-rich feedstock is a pure olefin feedstock.

20. The method according to claim 1, wherein: In the hydrogenation catalyst, the VIB group metal is Mo and / or W, and the VIII group metal is Co and / or Ni.

21. The method according to claim 1, wherein: The content of C5 and above olefins in the olefin-rich stream is greater than 80 wt %.

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