Method and device for producing low-carbon olefin by catalytic cracking of heavy hydrocarbon

Abstract

The invention discloses a method and a device for producing low-carbon olefin by catalytic cracking of heavy hydrocarbon, which can produce high-yield low-carbon olefin and carbon raw materials at the same time, improve the yield and selectivity of ethylene, propylene and butylene, reduce the yield of methane, reduce the alcohol content in the product to the greatest extent, and realize conversion of low-cost alcohol into low-carbon olefin. The method can realize high-selectivity conversion of olefin and alcohol into low-carbon olefin, solves the problem of overhigh yield of methanol cracking methane, maximally obtains ethylene and propylene, improves the selectivity of methane and coke, and realizes high-efficiency utilization of alcohol and fossil resources.

Description

Method and apparatus for producing low-carbon olefins by catalytic cracking of heavy hydrocarbons Technical Field

[0001] This application relates to the field of petroleum processing, specifically to a method and apparatus for producing low-carbon olefins by catalytic cracking of heavy hydrocarbons. Background Technology

[0002] With the rapid development of the national economy, environmental pollution has received increasing attention, and environmental regulations have become increasingly stringent, leading to a continued slowdown in the growth rate of refined oil demand. In the near future, demand for low-carbon olefins will remain strong, making the transformation of oil refining towards chemical production inevitable. Ethylene and propylene are two high-value basic organic chemical raw materials. Ethylene is an important basic organic chemical raw material, mainly used in the production of polyethylene, ethylene propylene rubber, polyvinyl chloride, ethanol, ethylene oxide, ethylene glycol, acetaldehyde, acetic acid, propionaldehyde, propionic acid and their derivatives, and other basic organic synthetic raw materials; it is widely used in the pharmaceutical and chemical industries. Propylene is an important basic chemical raw material for the production of propylene derivatives (such as polypropylene, acrylonitrile, and propylene oxide). Methyl tert-butyl ether has a high octane number and is widely used globally as a gasoline octane number blender. Similarly, catalytic light gasoline ether chemistry reacts reactive C5 and C6 olefins in catalytic cracking light gasoline with alcohols to produce alkyl tert-alkyl ethers, reducing the olefin content and vapor pressure of catalytic gasoline, while simultaneously converting low-value methanol into high-value gasoline products. This is a clean gasoline production process with considerable economic benefits.

[0003] CN102451674B discloses a catalyst for the cracking of methyl tert-butyl ether to isobutylene, its preparation method, and its application, with the aim of producing high-purity isobutylene. This method utilizes a catalyst prepared for the cracking of methyl tert-butyl ether to isobutylene, enabling the reaction to be completed under relatively high pressure, achieving high conversion and selectivity, and extending the equipment's operating cycle.

[0004] CN109225349A discloses a method for preparing a catalyst for the cracking of methyl tert-butyl ether to isobutylene. The catalyst prepared by this method can reduce the temperature required for the cracking reaction of methyl tert-butyl ether, has high selectivity for isobutylene and methanol, and also has a high conversion rate. It does not require the addition of inert substances such as water to the reaction system, has low energy consumption, and high equipment utilization.

[0005] CN109722303A discloses a method for producing low-sulfur marine fuel oil blending components from high-sulfur heavy oil. The method includes the following steps: a) high-sulfur heavy oil feedstock is fed into a viscous cracking unit for viscous cracking to obtain viscous residue oil; b) a composite modifier is added to the viscous residue oil obtained in step a), and the mixture is then subjected to continuous settling, resulting in overflow material at the top and underflow material at the bottom; c) the overflow material obtained in step b) is fed into a fixed-bed residue oil hydrotreating unit for hydrodesulfurization to obtain low-sulfur marine fuel oil blending components.

[0006] Most of the catalysts or processes disclosed in existing patents or literature for the cracking of methyl tert-butyl ether to produce olefins are used to produce high-purity olefins with four or more carbon atoms. For example, methyl tert-butyl ether cracking is used to produce high-purity isobutylene. Existing patents or literature disclose the cracking of heavy hydrocarbons to produce gasoline, low-carbon olefins, or low-sulfur marine fuel. However, there are very few reports on the use of ethers to produce low-carbon olefins such as ethylene and propylene, and the preparation of carbon material feedstocks from heavy hydrocarbons. Summary of the Invention

[0007] One objective of this application is to provide a method for maximizing the production of low-carbon olefins and carbon material feedstocks, which can simultaneously produce gasoline and carbon material feedstocks while increasing the production of low-carbon olefins, improving the yield and selectivity of ethylene, propylene and butene, and reducing the methane yield.

[0008] A first aspect of the present invention provides a method for producing low-carbon olefins by catalytic cracking of heavy hydrocarbons, comprising:

[0009] (1) A feedstock containing heavy hydrocarbons and ethers is reacted with a catalytic cracking catalyst in a catalytic cracking reactor to obtain catalytic cracking products, wherein the ethers have C n H 2n+1 -OC m H 2m+1 The structural formula is given, where m and n are integers greater than or equal to 1, preferably 1-10, more preferably 1-6, and most preferably 1-4;

[0010] (2) The catalytic cracking reaction products enter the separation unit for separation to obtain a first olefin stream containing ethylene and propylene, a second olefin stream containing butene, a gasoline stream, and catalytic wax oil.

[0011] (3) At least a portion of the second olefin stream, gasoline stream and optional external olefins enter the etherification unit to react with alcohol feedstock to produce recycled ethers and post-etherified olefins;

[0012] (4) At least a portion of the etherified olefins and optional externally sourced olefins enter the isomerization unit and react with the isomerization catalyst. The resulting isomerization product is returned to the etherification unit for further reaction.

[0013] (5) At least a portion of the recycled ethers and optional externally sourced ethers are returned to the catalytic cracking reactor for reaction.

[0014] A second aspect of the present invention provides a method for producing low-carbon olefins by catalytic cracking of heavy hydrocarbons, comprising:

[0015] (1) A feedstock containing heavy hydrocarbons and ethers is reacted with a catalytic cracking catalyst in a catalytic cracking reactor to obtain catalytic cracking products, wherein the ethers have C n H 2n+1 -OC m H 2m+1 The structural formula is given, where m and n are integers greater than or equal to 1, preferably 1-10, more preferably 1-6, and most preferably 1-4;

[0016] (2) The catalytic cracking reaction products enter the separation unit for separation to obtain a first olefin stream containing ethylene and propylene, a second olefin stream containing butene, a gasoline stream, and catalytic wax oil.

[0017] (3) At least a portion of the second olefin stream, gasoline stream and optional external olefins enter the etherification unit to react with alcohol feedstock to produce recycled ethers and post-etherified olefins;

[0018] (4) At least a portion of the etherified olefins and optional externally sourced olefins enter the isomerization unit and react with the isomerization catalyst. The resulting isomerization product is returned to the etherification unit for further reaction.

[0019] (5) At least a portion of the recycled ether material and optional externally sourced ether material enter the ether catalytic conversion reactor to react and obtain ether reaction products, which are then separated in a separation unit.

[0020] According to the method of the first or second aspect, in step (1), the heavy hydrocarbon is selected from petroleum hydrocarbons, mineral oils, or combinations thereof, wherein the petroleum hydrocarbon is selected from one or more of vacuum gas oil, atmospheric gas oil, coking gas oil, deasphalted oil, vacuum residue, atmospheric residue, and hydrotreated heavy oil, and the mineral oil is selected from one or more of coal liquefaction oil, oil sands oil, and shale oil; and / or

[0021] The ether raw material is selected from one or more of methyl tert-butyl ether, methyl tert-pentyl ether, methyl tert-hexyl ether, methyl tert-heptyl ether, methyl sec-butyl ether, methyl sec-pentyl ether, methyl sec-hexyl ether, methyl sec-heptyl ether, ethyl tert-butyl ether, ethyl tert-pentyl ether, ethyl tert-hexyl ether, ethyl tert-heptyl ether, ethyl sec-butyl ether, ethyl sec-pentyl ether, ethyl sec-hexyl ether, dimethyl ether, methyl ethyl ether, and diethyl ether; preferably, the ether raw material comes from an etherification unit, which is selected from a methyl tert-butyl ether unit, a light gasoline etherification unit, an ethyl tert-butyl ether unit, and combinations thereof.

[0022] According to the method of the first or second aspect, in step (1), the catalytic cracking reaction conditions include:

[0023] The reaction temperature is 460-750℃, preferably 500-700℃, more preferably 520-700℃, and most preferably 550-680℃;

[0024] The reaction time is 0.01-15 seconds, preferably 0.05-10 seconds, more preferably 0.1-8.0 seconds, and most preferably 0.15-7.0 seconds; and / or

[0025] The weight ratio of the agent to oil is 1-50, preferably 5-40, and more preferably 6-30.

[0026] According to the method of the first or second aspect, in step (1), the catalytic cracking reaction products include:

[0027] The mass fraction of methane is not greater than 5.0%, preferably not greater than 2.0%, and most preferably not greater than 1.0%.

[0028] The mass ratio of ethylene to methane is not less than 4.0, preferably not less than 8.0, and most preferably not less than 12; and / or

[0029] The mass fraction ratio of propylene to propane is not less than 10, preferably not less than 15, and most preferably not less than 30.

[0030] According to the method of the first or second aspect, in step (1), the catalytic cracking catalyst includes zeolite, and the zeolite comprises 20-100 wt% mesoporous zeolite and 0-80 wt% macroporous zeolite by total weight.

[0031] Preferably, the mesoporous zeolite is selected from ZSM series zeolites and ZRP zeolites, and the ZSM-type molecular sieve is preferably selected from ZSM-5, ZSN-8, ZSM-11 molecular sieves and hierarchical porous molecular sieves. The silicon-aluminum molar ratio (SiO2 / AlO3) of the molecular sieve is 50-1000, preferably 80-800, and most preferably 100-800; and / or

[0032] Preferably, the macroporous zeolite is a Y-series zeolite and / or a β-series zeolite molecular sieve;

[0033] More preferably, in the catalytic cracking catalyst, the mesoporous zeolite is a high-silica zeolite containing phosphorus and transition metals, and its anhydrous chemical expression, based on the mass of oxides, is (0-0.3)Na₂O·(0.3-5)Al₂O₃·(1-10)P₂O₅·(0.7-20)M x O y ·(70-95)SiO2, where element M is selected from one or more of rare earth elements, alkali metals and alkaline earth metals, Fe, Co, Ni, Cu, Zn, Mo and Mn, x is the oxidation state of oxygen, and y is the oxidation state of transition metal.

[0034] According to the method of the first or second aspect, in step (2), the 10% distillation point of the catalytic wax oil is not less than about 250°C, and the final distillation point is not greater than about 550°C; and / or

[0035] The total content of tricyclic and tetracyclic aromatic hydrocarbons in the catalytic wax oil is not less than about 35% by weight, preferably not less than 40%, and most preferably not less than 45%.

[0036] According to the method of the first or second aspect, in step (3), the etherification reaction conditions include:

[0037] The reaction temperature is 20-120℃, preferably 30-80℃, more preferably 35-75℃; and / or

[0038] The reaction pressure is 0-5.0 MPa, preferably 0.2-2.0 MPa, and more preferably 0.5-1.5 MPa;

[0039] Preferably, the alcohol raw material is selected from one or more of methanol, ethanol, propanol, butanol, and pentanol; more preferably, it is methanol, ethanol, or a combination thereof.

[0040] According to the method of the first or second aspect, in step (4), the isomerization reaction conditions include:

[0041] The reaction temperature is 150-500℃, preferably 250-480℃, more preferably 300-450℃, and most preferably 350-450℃; and / or

[0042] Heavy hourly space velocity is 1-30 h -1 Preferably 2-20h -1 More preferably 5-15h -1 .

[0043] According to the method of the first or second aspect, in step (4), the isomerization catalyst includes a support and a modified oxide, wherein the support includes a zeolite molecular sieve and a binder;

[0044] Preferably, the molecular sieve in the carrier has a mass fraction of 50-99%, and the binder has a mass fraction of 1-50%.

[0045] Preferably, the molecular sieve is a molecular sieve having MFI, FER, TON, and AEL structures, and the binder is alumina; and / or

[0046] Preferably, the modified oxide is a polyol, which is a C2 to C7 polyol selected from one or more of ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, glycerol, trimethylolethane, pentaerythritol, xylitol and sorbitol, and the mass ratio of the modified oxide to the carrier is preferably 0.01 to 0.3:1.

[0047] A third aspect of the present invention provides a heavy hydrocarbon catalytic cracking reactor, comprising:

[0048] A catalytic cracking reactor is used to react feedstock containing heavy hydrocarbons with a catalytic cracking catalyst in the reactor to obtain catalytic cracking products.

[0049] A separation unit, connected to a catalytic cracking reactor, is used to separate the catalytic cracking reaction products from the catalytic cracking reactor to obtain a first olefin stream containing ethylene and propylene, a second olefin stream containing butene, a gasoline stream, and catalytic wax oil.

[0050] An etherification unit, connected to the separation unit, wherein at least a portion of the second olefin stream, gasoline stream, and optionally externally sourced olefins from the separation unit react with an alcohol feedstock in the etherification unit to produce recycled ethers and post-etherified olefins.

[0051] An isomerization unit is connected to the etherification unit, such that at least a portion of the post-etherified olefin and optionally an externally sourced olefin enters the isomerization unit and reacts with the isomerization catalyst, and the resulting isomerization product is returned to the etherification unit for further reaction.

[0052] The etherification unit is also connected to the catalytic cracking reactor, so that at least a portion of the recycled ether material from the etherification unit and optionally externally sourced ether material enter the catalytic cracking reactor for reaction.

[0053] A fourth aspect of the present invention provides a heavy hydrocarbon catalytic cracking reactor, comprising:

[0054] A catalytic cracking reactor is used to react feedstock containing heavy hydrocarbons with a catalytic cracking catalyst in the reactor to obtain catalytic cracking products.

[0055] A separation unit, connected to a catalytic cracking reactor, is used to separate the catalytic cracking reaction products from the catalytic cracking reactor to obtain a first olefin stream containing ethylene and propylene, a second olefin stream containing butene, a gasoline stream, and catalytic wax oil.

[0056] An etherification unit, connected to the separation unit, wherein at least a portion of the second olefin stream, gasoline stream, and optionally externally sourced olefins from the separation unit react with an alcohol feedstock in the etherification unit to produce recycled ethers and post-etherified olefins.

[0057] An isomerization unit is connected to the etherification unit, such that at least a portion of the post-etherified olefin and optionally an externally sourced olefin enters the isomerization unit and reacts with the isomerization catalyst, and the resulting isomerization product is returned to the etherification unit for further reaction.

[0058] An ether catalytic conversion reactor is connected to the etherification unit, such that at least a portion of the recycled ether material and optionally externally sourced ether material enter the ether catalytic conversion reactor for reaction to obtain ether reaction products; the ether catalytic conversion reactor is also connected to the separation unit, such that the ether reaction products from the ether catalytic conversion reactor enter the separation unit for separation.

[0059] According to the apparatus of the third or fourth aspect, the catalytic cracking reactor is a fluidized bed reactor, which is a single fluidized bed reactor or a composite reactor obtained by connecting multiple fluidized bed reactors in series or in parallel;

[0060] Preferably, the catalytic cracking reactor is a constant diameter riser reactor or a variable diameter fluidized bed reactor, more preferably a variable diameter fluidized bed reactor.

[0061] Specifically, the method of this application has at least one of the following technical effects compared with the prior art:

[0062] 1. Ethers are prepared from olefins and alcohols, and alcohols can be produced at low cost from coal, low-quality high-sulfur coal and coke oven gas, as well as biomass (such as forest trees, organic waste, etc.), thereby achieving low-cost production of low-carbon olefins.

[0063] 2. Biomass is the process by which plants fix carbon dioxide using solar energy and store it in the form of chemical energy. Alcohols can be produced from biomass energy, which can then be reacted with alkenes to obtain ethers, and finally converted into low-carbon alkenes, thus enabling the recycling of carbon resources.

[0064] 3. This invention produces carbon material feedstock while simultaneously generating high yields of low-carbon olefins, increasing the yield and selectivity of ethylene, propylene, and butene, reducing methane yield, and minimizing the alcohol content in the products, thus achieving low-cost alcohol-to-olefin conversion. It enables highly selective conversion of olefins and alcohols into low-carbon olefins, while solving the problem of excessively high methane yield from alcohol cracking, maximizing the production of ethylene and propylene, and improving the selectivity of methane and coke, thereby achieving efficient utilization of alcohols and fossil resources. Attached Figure Description

[0065] Figure 1 shows a schematic diagram of a heavy hydrocarbon catalytic cracking reactor according to the present invention.

[0066] Figure 2 shows a schematic diagram of a heavy hydrocarbon catalytic cracking reactor according to the present invention.

[0067] Figure 3 shows a device diagram of a specific embodiment of the present invention.

[0068] Explanation of reference numerals in the attached figures:

[0069] 100. Catalytic cracking reactor; 200. Separation unit; 300. Etherification unit; 400. Isomerization unit; 101. Feedstock; 102. Catalytic cracking reaction products; 103. First olefin stream; 104. Second olefin stream; 105. Gasoline stream; 106. Catalytic wax oil; 107. Externally sourced olefins; 108. Alcohol feedstock; 109. Recycled ether feedstock; 110. Post-etherification olefins; 111. Non-olefin components; 112. Iso-olefins; 113. Ether reaction products;

[0070] 1. Pre-lifting medium pipeline; 2. Atomizing steam pipeline; 3. Ether pipeline; 4. Feed oil pipeline; 5. Second reaction zone condensate pipeline; 6. Settler; 7. First reaction zone; 8. Second reaction zone; 9. Stripping section; 10. Stripping steam pipeline; 11. Regenerator inclined tube; 12. Regenerator; 13. Main air pipeline; 14. Flue gas pipeline; 15. Regeneration inclined tube; 16. Main oil and gas pipeline; 17. Fractionation, absorption-stabilization unit; 18. Dry gas pipeline; 19. Liquefied petroleum gas pipeline; 20. Gasoline pipeline; 21. Diesel fuel. Pipeline; 22. Catalytic wax oil pipeline; 23. Gas separation unit; 24. Propylene pipeline; 25. Butene pipeline; 26. Isomerization unit; 27. Isoolefin pipeline; 28. Methanol; 29. ​​Gasoline separation unit; 30. <90℃ light gasoline pipeline; 31. Post-etherification olefins; 32. Etherification unit; 33. Post-etherification olefins pipeline; 34. Non-olefin component pipeline; 35. Recycled ether pipeline; 36. Other source ether pipeline; 37. Ether catalytic conversion reactor; 38. Second reaction zone of ether catalytic conversion reactor. Detailed Implementation

[0071] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. Through these descriptions, the features and advantages of the present application will become clearer and more apparent.

[0072] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0073] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0074] This invention provides a method for producing low-carbon olefins by catalytic cracking of heavy hydrocarbons, comprising:

[0075] (1) A feedstock containing heavy hydrocarbons and ethers is reacted with a catalytic cracking catalyst in a catalytic cracking reactor to obtain catalytic cracking products, wherein the ethers have C n H 2n+1 -OC m H 2m+1 The structural formula is given, where m and n are integers greater than or equal to 1, preferably 1-10, more preferably 1-6, and most preferably 1-4;

[0076] (2) The catalytic cracking reaction products enter the separation unit for separation to obtain a first olefin stream containing ethylene and propylene, a second olefin stream containing butene, a gasoline stream, and catalytic wax oil.

[0077] (3) At least a portion of the second olefin stream, gasoline stream and optional external olefins enter the etherification unit to react with alcohol feedstock to produce recycled ethers and post-etherified olefins;

[0078] (4) At least a portion of the etherified olefins and optional externally sourced olefins enter the isomerization unit and react with the isomerization catalyst. The resulting isomerization product is returned to the etherification unit for further reaction.

[0079] (5) At least a portion of the recycled ethers and optional externally sourced ethers are returned to the catalytic cracking reactor for reaction.

[0080] This invention provides a method for producing low-carbon olefins by catalytic cracking of heavy hydrocarbons, comprising:

[0081] (1) A feedstock containing heavy hydrocarbons and ethers is reacted with a catalytic cracking catalyst in a catalytic cracking reactor to obtain catalytic cracking products, wherein the ethers have C n H 2n+1 -OC m H 2m+1 The structural formula is given, where m and n are integers greater than or equal to 1, preferably 1-10, more preferably 1-6, and most preferably 1-4;

[0082] (2) The catalytic cracking reaction products enter the separation unit for separation to obtain a first olefin stream containing ethylene and propylene, a second olefin stream containing butene, a gasoline stream, and catalytic wax oil.

[0083] (3) At least a portion of the second olefin stream, gasoline stream and optional external olefins enter the etherification unit to react with alcohol feedstock to produce recycled ethers and post-etherified olefins;

[0084] (4) At least a portion of the etherified olefins and optional externally sourced olefins enter the isomerization unit and react with the isomerization catalyst. The resulting isomerization product is returned to the etherification unit for further reaction.

[0085] (5) At least a portion of the recycled ether material and optional externally sourced ether material enter the ether catalytic conversion reactor to react and obtain ether reaction products, which are then separated in a separation unit.

[0086] The method of this application includes: introducing at least a portion of the post-etherified olefins into an isomerization unit for isomerization in the presence of an isomerization catalyst to obtain isomerized olefins. The inventors of this application have discovered that, compared to isomerized olefins, the conversion rate of normal olefins to ethers via condensation reactions with alcohols is lower, resulting in a higher proportion of normal olefins in the post-etherified olefins after etherification. Simultaneously, ethers generated from the condensation reaction of isomerized olefins with alcohols are more readily converted into low-carbon olefins such as ethylene and propylene in catalytic conversion reactions. Therefore, at least a portion of the post-etherified olefins can be introduced into an isomerization unit for isomerization in the presence of an isomerization catalyst to obtain isomerized olefins; and as described above, these isomerized olefins are used as part of the olefin feedstock supplied to the etherification unit, further converting these isomerized olefins into corresponding ether compounds. The method of this invention produces low-carbon olefins such as ethylene and propylene, as well as catalytic wax oil for carbon materials, through the blending of heavy hydrocarbons and ethyl tert-butyl ether, maximizing the production of low-carbon olefins and carbon material feedstocks.

[0087] This invention provides a method for maximizing the production of low-carbon olefins and carbon material raw materials, comprising the following steps:

[0088] Ethers and feedstock oil react with catalytic cracking catalyst in a catalytic cracking reactor to obtain reaction products containing ethylene, propylene, butene, gasoline, and catalytic wax oil, wherein the total content of tricyclic and tetracyclic aromatic hydrocarbons in the catalytic wax oil is not less than 40%.

[0089] The butene, gasoline and / or other olefins are fed into an etherification unit to obtain ethers and post-etherified olefins. The post-etherified olefins and / or other olefins are fed into an isomerization unit to obtain isomerized olefins and then returned to the etherification unit.

[0090] The ethers and / or post-ether olefins enter the ether catalytic conversion reactor or are returned to the catalytic cracking reactor.

[0091] In one embodiment, in step (1), the heavy hydrocarbon is selected from petroleum hydrocarbons, mineral oils, or combinations thereof, wherein the petroleum hydrocarbon is selected from one or more of vacuum gas oil, atmospheric gas oil, coking gas oil, deasphalted oil, vacuum residue, atmospheric residue, and hydrotreated heavy oil, and the mineral oil is selected from one or more of coal liquefaction oil, oil sands oil, and shale oil; and / or

[0092] The ether raw material is selected from one or more of methyl tert-butyl ether, methyl tert-pentyl ether, methyl tert-hexyl ether, methyl tert-heptyl ether, methyl sec-butyl ether, methyl sec-pentyl ether, methyl sec-hexyl ether, methyl sec-heptyl ether, ethyl tert-butyl ether, ethyl tert-pentyl ether, ethyl tert-hexyl ether, ethyl tert-heptyl ether, ethyl sec-butyl ether, ethyl sec-pentyl ether, ethyl sec-hexyl ether, dimethyl ether, methyl ethyl ether, and diethyl ether; preferably, the ether raw material comes from an etherification unit, which is selected from a methyl tert-butyl ether unit, a light gasoline etherification unit, an ethyl tert-butyl ether unit, and combinations thereof.

[0093] In one embodiment, the catalytic cracking reaction conditions in step (1) include:

[0094] The reaction temperature is 460-750℃, preferably 500-700℃, more preferably 520-700℃, and most preferably 550-680℃;

[0095] The reaction time is 0.01-15 seconds, preferably 0.05-10 seconds, more preferably 0.1-8.0 seconds, and most preferably 0.15-7.0 seconds; and / or

[0096] The weight ratio of the agent to oil is 1-50, preferably 5-40, and more preferably 6-30.

[0097] In this application, reaction time refers to the residence time of the feedstock oil in the reactor. The catalyst-to-oil weight ratio refers to the weight ratio of the catalyst to the feedstock oil entering the reactor.

[0098] The inventors of this application have discovered that the reaction temperature of ether-based catalytic cracking significantly affects the compositional distribution of the catalytic conversion reaction products. When the temperature is below 200°C, etherified gasoline is converted into alcohols and olefins, with a low selectivity for low-carbon olefins (total ethylene and propylene), below 10%, which is not conducive to maximizing the production of low-carbon olefins. However, when the reaction temperature is increased to above 460°C, especially above 550°C, the selectivity for low-carbon olefins (total ethylene and propylene) in the products increases significantly, particularly the ethylene selectivity, and the ethylene / methane mass ratio decreases significantly, thereby maximizing the production of high-value-added low-carbon olefins.

[0099] The inventors of this application have discovered that, under appropriate catalytic conversion conditions, ether feedstocks can be readily cracked into C2 and C3 olefins (i.e., ethylene and propylene), as well as C4 or C5 olefins. + The above-mentioned alkenes. As described later, these are C4 or C5. + The above-mentioned alkenes can be converted into corresponding ether compounds through etherification reactions. These ether compounds can then undergo repeated catalytic conversion reactions to convert C4 or C5 alkenes into C5 alkenes. + The above olefins are further converted into low-carbon olefins such as ethylene and propylene.

[0100] The catalytic conversion products obtained above can be divided into dry gas components (mainly including ethylene, methane, ethane, etc.), liquefied petroleum gas components (mainly including propylene, as well as propane, butane, butene, etc.) and gasoline components (mainly including C5) according to their distillation range. + (The above-mentioned olefins, etc.). In this application, the proportion of non-olefin products such as methane, ethane, and propane in the catalytic conversion reaction products is low.

[0101] In one embodiment, in step (1), the catalytic cracking reaction products include:

[0102] The mass fraction of methane is not greater than 5.0%, preferably not greater than 2.0%, and most preferably not greater than 1.0%.

[0103] The mass ratio of ethylene to methane is not less than 4.0, preferably not less than 8.0, and most preferably not less than 12; and / or

[0104] The mass fraction ratio of propylene to propane is not less than 10, preferably not less than 15, and most preferably not less than 30.

[0105] In one embodiment, in step (1), the catalytic cracking catalyst includes zeolite, and the zeolite comprises 20-100 wt% mesoporous zeolite and 0-80 wt% macroporous zeolite by total weight.

[0106] Preferably, the mesoporous zeolite is selected from ZSM series zeolites and ZRP zeolites, and the ZSM-type molecular sieve is preferably selected from ZSM-5, ZSN-8, ZSM-11 molecular sieves and hierarchical porous molecular sieves. The silicon-aluminum molar ratio (SiO2 / AlO3) of the molecular sieve is 50-1000, preferably 80-800, and most preferably 100-800; and / or

[0107] Preferably, the macroporous zeolite is a Y-series zeolite and / or a β-series zeolite molecular sieve;

[0108] More preferably, in the catalytic cracking catalyst, the mesoporous zeolite is a high-silica zeolite containing phosphorus and transition metals, and its anhydrous chemical expression, based on the mass of oxides, is (0-0.3)Na₂O·(0.3-5)Al₂O₃·(1-10)P₂O₅·(0.7-20)M x O y ·(70-95)SiO2, where element M is selected from one or more of rare earth elements, alkali metals and alkaline earth metals, Fe, Co, Ni, Cu, Zn, Mo and Mn, x is the oxidation state of oxygen, and y is the oxidation state of transition metal.

[0109] In one embodiment, in step (2), the 10% distillation point of the catalytic wax oil is not less than about 250°C, and the final distillation point is not greater than about 550°C; and / or

[0110] The total content of tricyclic and tetracyclic aromatic hydrocarbons in the catalytic wax oil is not less than about 35% by weight, preferably not less than 40%, and most preferably not less than 45%.

[0111] In one embodiment, the etherification reaction conditions in step (3) include:

[0112] The reaction temperature is 20-120℃, preferably 30-80℃, more preferably 35-75℃; and / or

[0113] The reaction pressure is 0-5.0 MPa, preferably 0.2-2.0 MPa, and more preferably 0.5-1.5 MPa;

[0114] Preferably, the alcohol raw material is selected from one or more of methanol, ethanol, propanol, butanol, and pentanol; more preferably, it is methanol, ethanol, or a combination thereof.

[0115] The alcohol feedstock used in this application can be obtained at low cost from coal, low-quality high-sulfur coal and coke oven gas, as well as biomass (such as forest trees, organic waste, etc.), thereby achieving low-cost etherification reaction; biomass is the carbon dioxide fixed by plants through solar energy and stored in the form of chemical energy. Alcohols are prepared through biomass energy, further ethers are obtained, and finally converted into low-carbon olefins, which can realize the recycling of carbon resources and the low-cost production of low-carbon olefins.

[0116] Through this etherification reaction and etherification unit, higher olefins (such as butene) generated from the catalytic conversion of ether feedstocks, as well as isomerized olefins and external olefins described later, can be converted into corresponding ether compounds. These ether compounds can be fed as part of the feedstock into the catalytic conversion reactor for catalytic conversion, thereby converting C4 or C5 olefins into ether compounds. + The above olefins are further converted into low-carbon olefins such as ethylene and propylene. This can increase the yield of low-carbon olefins such as ethylene and propylene.

[0117] In one embodiment, the isomerization reaction conditions in step (4) include:

[0118] The reaction temperature is 150-500℃, preferably 250-480℃, more preferably 300-450℃, and most preferably 350-450℃; and / or

[0119] Heavy hourly space velocity is 1-30 h -1 Preferably 2-20h -1 More preferably 5-15h -1 .

[0120] In one embodiment, in step (4), the isomerization catalyst includes a support and a modified oxide, wherein the support includes a zeolite molecular sieve and a binder;

[0121] Preferably, the molecular sieve in the carrier has a mass fraction of 50-99%, and the binder has a mass fraction of 1-50%.

[0122] Preferably, the molecular sieve is a molecular sieve having MFI, FER, TON, and AEL structures, and the binder is alumina; and / or

[0123] Preferably, the modified oxide is a polyol, which is a C2 to C7 polyol selected from one or more of ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, glycerol, trimethylolethane, pentaerythritol, xylitol and sorbitol, and the mass ratio of the modified oxide to the carrier is preferably 0.01 to 0.3:1.

[0124] The present invention also provides a heavy hydrocarbon catalytic cracking reactor, comprising:

[0125] A catalytic cracking reactor is used to react feedstock containing heavy hydrocarbons with a catalytic cracking catalyst in the reactor to obtain catalytic cracking products.

[0126] A separation unit, connected to a catalytic cracking reactor, is used to separate the catalytic cracking reaction products from the catalytic cracking reactor to obtain a first olefin stream containing ethylene and propylene, a second olefin stream containing butene, a gasoline stream, and catalytic wax oil.

[0127] An etherification unit, connected to the separation unit, wherein at least a portion of the second olefin stream, gasoline stream, and optionally externally sourced olefins from the separation unit react with an alcohol feedstock in the etherification unit to produce recycled ethers and post-etherified olefins.

[0128] An isomerization unit is connected to the etherification unit, such that at least a portion of the post-etherified olefin and optionally an externally sourced olefin enters the isomerization unit and reacts with the isomerization catalyst, and the resulting isomerization product is returned to the etherification unit for further reaction.

[0129] The etherification unit is also connected to the catalytic cracking reactor, so that at least a portion of the recycled ether material from the etherification unit and optionally externally sourced ether material enter the catalytic cracking reactor for reaction.

[0130] The present invention further provides a heavy hydrocarbon catalytic cracking reactor, comprising:

[0131] A catalytic cracking reactor is used to react feedstock containing heavy hydrocarbons with a catalytic cracking catalyst in the reactor to obtain catalytic cracking products.

[0132] A separation unit, connected to a catalytic cracking reactor, is used to separate the catalytic cracking reaction products from the catalytic cracking reactor to obtain a first olefin stream containing ethylene and propylene, a second olefin stream containing butene, a gasoline stream, and catalytic wax oil.

[0133] An etherification unit, connected to the separation unit, wherein at least a portion of the second olefin stream, gasoline stream, and optionally externally sourced olefins from the separation unit react with an alcohol feedstock in the etherification unit to produce recycled ethers and post-etherified olefins.

[0134] An isomerization unit is connected to the etherification unit, such that at least a portion of the post-etherified olefin and optionally an externally sourced olefin enters the isomerization unit and reacts with the isomerization catalyst, and the resulting isomerization product is returned to the etherification unit for further reaction.

[0135] An ether catalytic conversion reactor is connected to the etherification unit, such that at least a portion of the recycled ether material and optionally externally sourced ether material enter the ether catalytic conversion reactor for reaction to obtain ether reaction products; the ether catalytic conversion reactor is also connected to the separation unit, such that the ether reaction products from the ether catalytic conversion reactor enter the separation unit for separation.

[0136] In one embodiment, the catalytic cracking reactor is a fluidized bed reactor, which is a single fluidized bed reactor or a composite reactor obtained by connecting multiple fluidized bed reactors in series or in parallel;

[0137] Preferably, the catalytic cracking reactor is a constant diameter riser reactor or a variable diameter fluidized bed reactor, more preferably a variable diameter fluidized bed reactor.

[0138] In this invention, the catalytic cracking reactor is selected from any one and / or a combination of two or more reactor types, such as fixed bed, moving bed, and fluidized bed reactors; preferably, the fixed bed reactor is selected from two or more reactors connected in series or parallel; optionally, the fluidized bed reactor is selected from one or more reactors connected in series or parallel, such as constant diameter riser, constant linear velocity riser, variable diameter riser, fluidized bed and composite reactor composed of constant diameter riser and fluidized bed, upward conveying line, and downward conveying line.

[0139] In one embodiment, the catalytic cracking reactor can be a fluidized bed reactor of various forms, such as a single fluidized bed reactor or a composite reactor obtained by combining multiple fluidized bed reactors in series or parallel. In some preferred embodiments, the fluidized bed reactor can be a constant-diameter riser reactor or a fluidized bed reactor of various variable diameter forms, such as the reactor disclosed in Chinese Patent CN112569875A.

[0140] The separation unit of the present invention can be a common separation device in the art, such as a fractionation tower, which can separate the components into different components according to their distillation range. For example, catalytic cracking reaction products can be separated into dry gas components, liquefied petroleum gas components, gasoline components, diesel components, and slurry components in a fractionation tower, and then ethylene components can be separated from the dry gas components in another separation device, propylene components can be separated from the liquefied petroleum gas components in another separation device, and FGO components can be separated from the slurry components.

[0141] In the etherification unit of this invention, olefin feedstock and alcohol feedstock can react in the presence of a catalyst to obtain the corresponding ether. This etherification reaction can be carried out using processes known in the art.

[0142] For example, in the presence of an acid catalyst, olefin feedstocks can be brought into contact with alcohol feedstocks to undergo a condensation reaction, thereby generating the corresponding ethers. Commonly used acid catalysts include sulfuric acid, phosphoric acid, and aluminum trichloride.

[0143] In the presence of an alkaline catalyst, olefin feedstocks can be brought into contact with alcohol feedstocks to undergo a condensation reaction, thereby generating the corresponding ethers. Commonly used alkaline catalysts include sodium hydroxide, potassium hydroxide, and sodium carbonate.

[0144] In the presence of a metal catalyst, olefin feedstocks can be brought into contact with alcohol feedstocks to undergo a condensation reaction, thereby generating the corresponding ethers. Commonly used metal catalysts include copper, iron, and palladium.

[0145] Figure 1 shows a schematic diagram of a heavy hydrocarbon catalytic cracking reactor according to the present invention, comprising:

[0146] Catalytic cracking reactor 100 is used to contact and react feedstock containing heavy hydrocarbons with catalytic cracking catalyst in the catalytic cracking reactor to obtain catalytic cracking reaction products.

[0147] Separation unit 200, which is connected to catalytic cracking reactor 100, is used to separate catalytic cracking reaction products from catalytic cracking reactor to obtain a first olefin stream containing ethylene and propylene, a second olefin stream containing butene, a gasoline stream, and catalytic wax oil.

[0148] Etherification unit 300, which is connected to separation unit 200, so that the second olefin stream and gasoline stream from separation unit react with alcohol feedstock in etherification unit to obtain recycled ether material and etherified olefin;

[0149] Isomerization unit 400 is connected to etherification unit 300, so that the etherified olefin enters the isomerization unit and reacts with the isomerization catalyst, and the resulting isomerization product is returned to etherification unit 300 for further reaction.

[0150] The etherification unit 300 is also connected to the catalytic cracking reactor 100, so that the recycled ether material from the etherification unit enters the catalytic cracking reactor for reaction.

[0151] Feedstock oil 101 containing heavy hydrocarbons is fed into catalytic cracking reactor 100 and reacts with catalytic cracking catalyst to obtain catalytic cracking product 102. Catalytic cracking product 102 is then separated in separation unit 200 to obtain a first olefin stream 103 containing the target products ethylene and propylene, a second olefin stream 104 containing butene, a gasoline stream 105, and the target product catalytic wax oil 106. The second olefin stream 104 containing butene, the gasoline stream 105, and optional externally sourced olefins 107 are fed into etherification unit 300 and react with alcohol feedstock 108 to obtain recycled ether material 109 and post-etherified olefins 110. Recycled ether material 109 is returned to catalytic cracking reactor 100 for further reaction, and post-etherified olefins 110 are fed into isomerization unit 400 for isomerization reaction. The resulting isomerized olefins 112 are returned to the etherification unit for further reaction, and non-olefin components 111 are sent downstream.

[0152] Figure 2 shows a schematic diagram of a heavy hydrocarbon catalytic cracking reactor according to the present invention, comprising:

[0153] Catalytic cracking reactor 100 is used to contact and react feedstock containing heavy hydrocarbons with catalytic cracking catalyst in the catalytic cracking reactor to obtain catalytic cracking reaction products.

[0154] Separation unit 200, which is connected to catalytic cracking reactor 100, is used to separate catalytic cracking reaction products from catalytic cracking reactor to obtain a first olefin stream containing ethylene and propylene, a second olefin stream containing butene, a gasoline stream, and catalytic wax oil.

[0155] Etherification unit 300, which is connected to separation unit 100, allows a second olefin stream, a gasoline stream and optional externally sourced olefins from the separation unit to react with alcohol feedstock in the etherification unit to produce recycled ethers and post-etherified olefins.

[0156] Isomerization unit 400 is connected to etherification unit 300, so that the etherified olefin enters the isomerization unit and reacts with the isomerization catalyst, and the resulting isomerization product is returned to the etherification unit for further reaction.

[0157] An ether catalytic conversion reactor 500 is connected to the etherification unit 300, allowing recycled ether materials and optionally externally sourced ether materials to enter the ether catalytic conversion reactor for reaction to obtain ether reaction products; the ether catalytic conversion reactor 500 is also connected to the separation unit 200, allowing the ether reaction products from the ether catalytic conversion reactor to enter the separation unit for separation;

[0158] Feedstock oil 101 containing heavy hydrocarbons is fed into catalytic cracking reactor 100 and reacts with catalytic cracking catalyst to obtain catalytic cracking product 102. Catalytic cracking product 102 is then separated in separation unit 200 to obtain a first olefin stream 103 containing the target products ethylene and propylene, a second olefin stream 104 containing butene, gasoline stream 105, and catalytic wax oil 106 containing the target product. The second olefin stream 104 containing butene, gasoline stream 105, and optional externally sourced olefins 107 are then fed into etherification unit 300 and reacted with alcohol feedstock 108 to obtain recycled ether material 109 and post-etherified olefins 110. Post-etherified olefins 110 are then fed into isomerization unit 400 for isomerization, and the resulting isomerized olefins 112 are returned to the etherification unit for further reaction, while non-olefin components 111 are sent downstream. Recycled ether material 109 is then fed into ether catalytic conversion reactor 500 to obtain ether reaction product 113, which is then separated in separation unit 200.

[0159] The following description, in conjunction with Figure 3, illustrates a specific implementation of the method of this application, but does not limit the scope of this application.

[0160] The pre-lifting medium enters from the bottom of the variable-diameter fluidized bed reactor (e.g., the reactor disclosed in Chinese Patent CN112569875A) via pipeline 1. Ethers, along with atomized steam from pipeline 2, are injected into the bottom of the first reaction zone 7 of the variable-diameter fluidized bed reactor via pipeline 3 and nozzles. They contact the regenerated catalyst from the regeneration inclined tube 15 within the reactor, then contact the feed oil from pipeline 4 and move upwards into the second reaction zone 8 of the variable-diameter fluidized bed reactor to continue the reaction. The generated oil and gas, along with the deactivated catalyst, enter the cyclone separator in the settling tank 6 to separate the catalyst from the oil and gas. The reacted oil and gas enter the main oil and gas pipeline 16, while the catalyst powder returns to the settling tank 6 via the cyclone separator feed leg. The catalyst in the settling tank 6 flows to the stripping section 9, where it contacts the stripping steam from pipeline 10. The oil and gas stripped from the catalyst enters the main oil and gas pipeline 16 after passing through the cyclone separator. After stripping, the spent catalyst enters the regenerator 12 through the spent catalyst inclined tube 11. The main air enters the regenerator through pipeline 13 to burn off the coke on the spent catalyst, thus regenerating the deactivated spent catalyst. The flue gas is then led out through pipeline 14. The regenerated catalyst enters the variable diameter fluidized bed reactor for recycling through the first regeneration inclined tube 15. The reacted oil and gas enter the fractionation, absorption-stabilization unit 17 via the main oil and gas pipeline 16. The separated dry gas is led out via pipeline 18 and separated to obtain ethylene. The liquefied gas is introduced into the gas separation unit 23 via pipeline 19 and separated into propylene, which is then sent out via pipeline 24. The gasoline from pipeline 20 is sent to the separation unit 29 to obtain light gasoline with a temperature of <90°C. The gasoline, along with butene from pipeline 25 and methanol from pipeline 28, is sent to the etherification unit 32 via pipeline 30. The unreacted non-olefin components are sent to the downstream unit via pipeline 34. The unreacted components containing n-olefins are sent to the isomerization unit 26 via pipeline 33 to obtain isoolefins. The isoolefins are recycled to the etherification unit 32 via pipeline 27. In one embodiment (not shown in the figure), ethers are sent via pipeline 35 and other ethers from other sources to the catalytic cracking reactor to react and increase the production of low-carbon olefins. In another embodiment (as shown in Figure 3), ethers are fed into the ether catalytic conversion reactor 37 via pipeline 35 and other ethers from other sources via pipeline 36. The resulting ether reaction products and the spent catalyst enter a settling tank for separation. The separated ether reaction products enter the fractionation, absorption-stabilization unit 17 via the main oil and gas pipeline 16 for further separation and recycling. The spent catalyst, after stripping, enters the regenerator via the spent catalyst inclined tube 11. The regenerated regenerant returns to the ether catalytic conversion reactor 37 via the second regeneration inclined tube. Diesel fuel and catalytic wax oil are led out via pipelines 21 and 22, respectively.

[0161] The present application will be further described below with reference to the embodiments, but this does not limit the present application. The properties of the feedstock oils used in the embodiments and comparative examples are shown in Table 1. The catalysts used in the embodiments and comparative examples are commercially available catalytic conversion catalysts with the brand name TCC-1, manufactured by Sinopec Catalyst Qilu Branch. The isomerization catalysts used in the embodiments are commercially available catalysts with the brand name FI-15, manufactured by Sinopec Petrochemical Research Institute. The catalysts used in the etherification units in the embodiments are consistent with the catalysts used in the embodiments, namely CN101245255B.

[0162] Table 1. Properties of raw materials in examples and comparative examples.

[0163]

[0164]

[0165] Example 1

[0166] The experiment was conducted according to the catalytic cracking unit flow chart shown in Figure 3 (the specific structure of the variable-diameter fluidized bed reactor is shown in Example 1 of CN112569875A). The feedstock, VGO, entered the heavy hydrocarbon reactor, while 50% of the feedstock, methyl tert-butyl ether, entered the ether catalytic conversion reactor, using TCC-1 as the catalyst. Target products such as ethylene, propylene, and catalytic wax oil were obtained. The reaction conditions and product distribution are listed in Table 2.

[0167] Comparative Example 1

[0168] The experiment was conducted according to the catalytic cracking unit flow chart shown in Figure 3 (the specific structure of the variable-diameter fluidized bed reactor is shown in Example 1 of CN112569875A). The feedstock, VGO, entered the heavy hydrocarbon reactor, while 50% of the feedstock, methyl tert-butyl ether, entered the ether catalytic conversion reactor, using TCC-1 as the catalyst. Target products such as ethylene, propylene, and catalytic wax oil were obtained. The reaction conditions and product distribution are listed in Table 2. The difference from the example is that the reaction temperature of the ether catalytic conversion reactor was 450°C.

[0169] Example 2

[0170] The experiment was conducted according to the catalytic cracking unit flow chart shown in Figure 3 (the specific structure of the variable-diameter fluidized bed reactor is shown in Example 1 of CN112569875A). The feedstock was hydrotreated heavy oil, which entered the heavy hydrocarbon reactor. Methyl tert-butyl ether, which accounted for 50% of the feedstock, entered the ether catalytic conversion reactor, using TCC-1 as the catalyst. Target products such as ethylene, propylene, and catalytic wax oil were obtained. The reaction conditions and product distribution are listed in Table 3.

[0171] The properties of the target product carbon material raw material catalytic wax oil obtained in the examples and comparative examples are shown in Table 4.

[0172] Table 2. Reaction conditions and product distribution of the examples and comparative examples.

[0173]

[0174]

[0175] Table 3 Reaction conditions and product distribution in Example 2

[0176]

[0177]

[0178] Table 4 shows the properties of carbon material feedstock (catalytic wax oil) in the examples.

[0179]

[0180] The preferred embodiments of this application have been described in detail above. However, this application is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this application, various simple modifications can be made to the technical solution of this application, and these simple modifications all fall within the protection scope of this application.

[0181] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this application will not describe the various possible combinations separately.

[0182] Furthermore, various embodiments of this application can be combined arbitrarily, as long as they do not violate the spirit of this application, and should also be considered as the content disclosed in this application. The above description of this application is based on preferred embodiments; however, these embodiments are merely exemplary and illustrative. Based on this, various substitutions and improvements can be made to this application, all of which fall within the protection scope of this application.

Claims

1. A method for producing low-carbon olefins by catalytic cracking of heavy hydrocarbons, comprising: (1) A feedstock containing heavy hydrocarbons and ethers is reacted with a catalytic cracking catalyst in a catalytic cracking reactor to obtain catalytic cracking products, wherein the ethers have C n H 2n+1 -OC m H 2m+1 The structural formula is given, wherein m and n are integers greater than or equal to 1, preferably 1-10, more preferably 1-6, and most preferably 1-4; (2) the catalytic cracking reaction products enter the separation unit for separation to obtain a first olefin stream containing ethylene and propylene, a second olefin stream containing butene, a gasoline stream, and catalytic wax oil; (3) at least a portion of the second olefin stream, gasoline stream, and optional externally sourced olefins enter the etherification unit to react with alcohol feedstock to obtain recycled ether materials and post-etherified olefins; (4) at least a portion of the post-etherified olefins and optional externally sourced olefins enter the isomerization unit to react with the isomerization catalyst, and the obtained isomerization products are returned to the etherification unit for reaction; (5) at least a portion of the recycled ether materials and optional externally sourced ether materials are returned to the catalytic cracking reactor for reaction.

2. A method for producing low-carbon olefins by catalytic cracking of heavy hydrocarbons, comprising: (1) A feedstock containing heavy hydrocarbons and ethers is reacted with a catalytic cracking catalyst in a catalytic cracking reactor to obtain catalytic cracking products, wherein the ethers have C n H 2n+1 -OC m H 2m+1 The structural formula is given, wherein m and n are integers greater than or equal to 1, preferably 1-10, more preferably 1-6, and most preferably 1-4; (2) the catalytic cracking reaction products enter the separation unit for separation to obtain a first olefin stream containing ethylene and propylene, a second olefin stream containing butene, a gasoline stream, and catalytic wax oil; (3) at least a portion of the second olefin stream, gasoline stream, and optional externally sourced olefins enter the etherification unit to react with alcohol feedstock to obtain recycled ether materials and post-etherified olefins; (4) at least a portion of the post-etherified olefins and optional externally sourced olefins enter the isomerization unit to react with the isomerization catalyst, and the obtained isomerization products are returned to the etherification unit for reaction; (5) at least a portion of the recycled ether materials and optional externally sourced ether materials enter the ether catalytic conversion reactor for reaction to obtain ether reaction products, and the ether reaction products enter the separation unit for separation.

3. The method according to claim 1 or 2, characterized in that, In step (1), the heavy hydrocarbon is selected from petroleum hydrocarbons, mineral oils, or combinations thereof, wherein the petroleum hydrocarbon is selected from one or more of vacuum gas oil, atmospheric gas oil, coking gas oil, deasphalted oil, vacuum residue, atmospheric residue, and hydrotreated heavy oil, and the mineral oil is selected from one or more of coal liquefaction oil, oil sands oil, and shale oil; and / or the ether feedstock is selected from one or more of methyl tert-butyl ether, methyl tert-amyl ether, methyl tert-hexyl ether, methyl tert-heptyl ether, methyl sec-butyl ether, methyl sec-amyl ether, methyl sec-hexyl ether, methyl sec-heptyl ether, ethyl tert-butyl ether, ethyl tert-amyl ether, ethyl tert-hexyl ether, ethyl tert-heptyl ether, ethyl sec-butyl ether, ethyl sec-amyl ether, ethyl sec-hexyl ether, ethyl sec-heptyl ether, dimethyl ether, methyl ethyl ether, and diethyl ether; preferably, the ether feedstock comes from an etherification unit, and the etherification unit is selected from a methyl tert-butyl ether unit, a light gasoline etherification unit, an ethyl tert-butyl ether unit, or combinations thereof.

4. The method according to claim 1 or 2, characterized in that, In step (1), the catalytic cracking reaction conditions include: a reaction temperature of 460-750℃, preferably 500-700℃, more preferably 520-700℃, and most preferably 550-680℃; a reaction time of 0.01-15 seconds, preferably 0.05-10 seconds, more preferably 0.1-8.0 seconds, and most preferably 0.15-7.0 seconds; and / or an additive-to-oil weight ratio of 1-50, preferably 5-40, and more preferably 6-30.

5. The method according to claim 1 or 2, characterized in that, In step (1), the catalytic cracking reaction products contain: methane with a mass fraction of not more than 5.0%, preferably not more than 2.0%, and most preferably not more than 1.0%; ethylene to methane mass ratio of not less than 4.0, preferably not less than 8.0, and most preferably not less than 12; and / or propylene to propane mass fraction ratio of not less than 10, preferably not less than 15, and most preferably not less than 30.

6. The method according to claim 1 or 2, characterized in that, In step (1), the catalytic cracking catalyst includes zeolite, which, by total weight, comprises 20-100 wt% mesoporous zeolite and 0-80 wt% macroporous zeolite; preferably, the mesoporous zeolite is selected from ZSM series zeolite and ZRP zeolite, and the ZSM type molecular sieve is preferably selected from ZSM-5, ZSN-8, ZSM-11 molecular sieve and hierarchical porous molecular sieve, wherein the silicon-aluminum molar ratio of the molecular sieve is SiO2 / Al. The O3 concentration is 50-1000, preferably 80-800, and most preferably 100-800; and / or preferably, the macroporous zeolite is a Y-series zeolite and / or a β-series zeolite molecular sieve; more preferably, in the catalytic cracking catalyst, the mesoporous zeolite is a high-silica zeolite containing phosphorus and transition metals, and its anhydrous chemical expression, based on the mass of oxides, is (0-0.3)Na2O·(0.3-5)Al2O3·(1-10)P2O5·(0.7-20)M x O y ·(70-95)SiO2, where element M is selected from one or more of rare earth elements, alkali metals and alkaline earth metals, Fe, Co, Ni, Cu, Zn, Mo and Mn, x is the oxidation state of oxygen, and y is the oxidation state of transition metal.

7. The method according to claim 1 or 2, characterized in that, In step (2), the 10% distillation point of the catalytic wax oil is not less than about 250°C and the final distillation point is not greater than about 550°C; and / or the total content of tricyclic and tetracyclic aromatic hydrocarbons in the catalytic wax oil is not less than about 35% by weight, preferably not less than 40%, and most preferably not less than 45%.

8. The method according to claim 1 or 2, characterized in that, In step (3), the etherification reaction conditions include: a reaction temperature of 20-120℃, preferably 30-80℃, more preferably 35-75℃; and / or a reaction pressure of 0-5.0MPa, preferably 0.2-2.0MPa, more preferably 0.5-1.5MPa; preferably, the alcohol raw material is selected from one or more of methanol, ethanol, propanol, butanol, and pentanol; more preferably, methanol, ethanol, or a combination thereof.

9. The method according to claim 1 or 2, characterized in that, In step (4), the isomerization reaction conditions include: a reaction temperature of 150-500℃, preferably 250-480℃, more preferably 300-450℃, and most preferably 350-450℃; and / or a heavy hourly space velocity of 1-30 h⁻¹. -1 Preferably 2-20h -1 More preferably 5-15h -1 .

10. The method according to claim 1 or 2, characterized in that, In step (4), the isomerization catalyst includes a support and a modified oxide, wherein the support includes a zeolite molecular sieve and a binder; preferably, the mass fraction of the molecular sieve in the support is 50-99%, and the mass fraction of the binder is 1-50%; preferably, the molecular sieve is a molecular sieve with an MFI structure, FER structure, TON structure and AEL structure, and the binder is alumina; and / or preferably, the modified oxide is a polyol, the polyol is a C2-C7 polyol, selected from one or more of ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, glycerol, trimethylolethane, pentaerythritol, xylitol and sorbitol, and the mass ratio of the modified oxide to the support is preferably 0.01-0.3:

1.

11. A heavy hydrocarbon catalytic cracking reactor, comprising: A catalytic cracking reactor is used to react feedstock containing heavy hydrocarbons with a catalytic cracking catalyst in the reactor to obtain catalytic cracking products. A separation unit, connected to a catalytic cracking reactor, is used to separate the catalytic cracking reaction products from the catalytic cracking reactor to obtain a first olefin stream containing ethylene and propylene, a second olefin stream containing butene, a gasoline stream, and catalytic wax oil. An etherification unit, connected to the separation unit, wherein at least a portion of the second olefin stream, gasoline stream, and optionally externally sourced olefins from the separation unit react with an alcohol feedstock in the etherification unit to produce recycled ethers and post-etherified olefins. An isomerization unit is connected to the etherification unit, such that at least a portion of the post-etherified olefins and optionally externally sourced olefins enter the isomerization unit to react with the isomerization catalyst, and the resulting isomerization product is returned to the etherification unit for further reaction; wherein, the etherification unit is also connected to the catalytic cracking reactor, such that at least a portion of the recycled ethers from the etherification unit and optionally externally sourced ethers enter the catalytic cracking reactor for further reaction.

12. A heavy hydrocarbon catalytic cracking reactor, comprising: A catalytic cracking reactor is used to react feedstock containing heavy hydrocarbons with a catalytic cracking catalyst in the reactor to obtain catalytic cracking products. A separation unit, connected to a catalytic cracking reactor, is used to separate the catalytic cracking reaction products from the catalytic cracking reactor to obtain a first olefin stream containing ethylene and propylene, a second olefin stream containing butene, a gasoline stream, and catalytic wax oil. An etherification unit, connected to the separation unit, wherein at least a portion of the second olefin stream, gasoline stream, and optionally externally sourced olefins from the separation unit react with an alcohol feedstock in the etherification unit to produce recycled ethers and post-etherified olefins. An isomerization unit is connected to the etherification unit, such that at least a portion of the post-etherified olefin and optionally an externally sourced olefin enters the isomerization unit and reacts with the isomerization catalyst, and the resulting isomerization product is returned to the etherification unit for further reaction. An ether catalytic conversion reactor is connected to the etherification unit, such that at least a portion of the recycled ether material and optionally externally sourced ether material enter the ether catalytic conversion reactor for reaction to obtain ether reaction products; the ether catalytic conversion reactor is also connected to the separation unit, such that the ether reaction products from the ether catalytic conversion reactor enter the separation unit for separation.

13. The apparatus according to claim 11 or 12, characterized in that, The catalytic cracking reactor is a fluidized bed reactor, which can be a single fluidized bed reactor or a composite reactor obtained by connecting multiple fluidized bed reactors in series or in parallel; preferably, the catalytic cracking reactor is a constant diameter riser reactor or a variable diameter fluidized bed reactor, more preferably a variable diameter fluidized bed reactor.

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