Heavy hydrocarbon catalytic cracking method and device

Abstract

The invention discloses a heavy hydrocarbon catalytic cracking method and a heavy hydrocarbon catalytic cracking device, which are used for producing a carbon material raw material while increasing the yield of low-carbon olefin, improving the yield and selectivity of ethylene, propylene and butylene, reducing the yield of methane, reducing the content of ethanol in the product to the greatest extent and realizing low-cost conversion of ethanol into low-carbon olefin. The method can realize high-selectivity conversion of olefin and ethanol into low-carbon olefin, solves the problem of overhigh yield of ethanol cracking methane, maximally obtains ethylene and propylene, improves the selectivity of methane and coke, and realizes efficient utilization of ethanol and fossil resources.

Description

Technical Field

[0001] This application pertains to the field of petroleum processing, specifically relating to a method and apparatus for 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). Ethyl tert-butyl ether has a high octane number and is widely used globally as a gasoline octane number modifier. 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 ethers to produce olefins are used to produce high-purity olefins with four or more carbon atoms. For example, methyl tert-butyl ether is cracked 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 fuels. However, there are very few reports on the use of ethyl tert-butyl ether to produce low-carbon olefins such as ethylene and propylene, or 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 carbon material feedstocks while increasing the production of low-carbon olefins, improving the yield and selectivity of ethylene, propylene and butene, reducing the methane yield, and minimizing the ethanol content in the products, thereby achieving low-cost ethanol-to-low-carbon olefin conversion.

[0008] A first aspect of the present invention provides a method for catalytic cracking of heavy hydrocarbons, comprising:

[0009] (1) The feedstock containing heavy hydrocarbons is reacted with the catalytic cracking catalyst in a catalytic cracking reactor to obtain catalytic cracking reaction products;

[0010] (2) The catalytic cracking reaction products enter the separation unit for separation to obtain a first olefin stream containing butene;

[0011] (3) At least a portion of the first olefin stream and optional externally sourced olefins enter the etherification unit and react with ethanol to give recycled ethyl tert-butyl ether and post-etherified olefins;

[0012] (4) At least a portion of the recycled ethyl tert-butyl ether enters the ether catalytic conversion reactor and optionally at least a portion of the ether post-olefins enter the ether catalytic conversion reactor to react, and the ether reaction products enter the separation unit.

[0013] (5) 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 isomerized product is returned to the etherification unit for further reaction.

[0014] According to the method of the first aspect, 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.

[0015] According to the method of the first aspect, in step (1), the feed oil contains ethyl tert-butyl ether;

[0016] Preferably, the mass fraction of ethyl tert-butyl ether in the feedstock oil is not less than 20%, more preferably not less than 30%, more preferably not less than 50%, and most preferably not less than 80%.

[0017] According to the method of the first aspect, in step (1), the catalytic cracking reaction conditions include:

[0018] The reaction temperature is 460-750℃, preferably 480-700℃, more preferably 480-600℃, and most preferably 520-580℃;

[0019] Heavy hourly space velocity is 5-100 h -1 Preferably 10-70h -1 , more preferably 15-50h -1 The optimal time is 18-40 hours. -1 ;

[0020] The reaction time is 1-15 seconds, preferably 1.5-15 seconds, more preferably 2.0-15.0 seconds, and most preferably 5.0-10.0 seconds; and / or

[0021] The weight ratio of the agent to oil is 1-30, preferably 5-15, and more preferably 6-10.

[0022] According to the method of the first aspect, in step (1), the catalytic cracking catalyst includes zeolite, and the zeolite comprises 61-100 wt% mesoporous zeolite and 0-60 wt% macroporous zeolite by total weight, wherein the mesoporous zeolite has a high silica-alumina ratio of greater than 10, preferably greater than 50, and most preferably greater than 100.

[0023] Preferably, the mesoporous zeolite is selected from ZSM series zeolites and ZRP zeolites, and more preferably one or more of ZSM-5, ZSM-8 and ZSM-11; the macroporous zeolite is a Y series zeolite or a β series zeolite molecular sieve.

[0024] More preferably, the catalytic cracking catalyst includes a high-silica zeolite, which 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.

[0025] According to the method of the first aspect, in step (2), the catalytic cracking reaction product further includes a second olefin stream containing ethylene and propylene, gasoline and catalytic wax oil;

[0026] Preferably, the catalytic wax oil has a 10% distillation point of not less than 250°C and a final distillation point of not more than 550°C; and / or

[0027] The total content of tricyclic and tetracyclic aromatic hydrocarbons in the catalytic wax oil is not less than 35% by weight, preferably not less than 40%, and most preferably not less than 45%.

[0028] According to the method of the first aspect, in step (3), the etherification reaction conditions include:

[0029] The reaction temperature is 20-120℃, preferably 30-80℃, more preferably 35-75℃; and / or

[0030] The reaction pressure is 0-5.0 MPa, preferably 0.2-2.0 MPa, and more preferably 0.5-1.5 MPa.

[0031] According to the method of the first aspect, in step (5), the isomerization reaction conditions include:

[0032] The reaction temperature is 150-500℃, preferably 250-480℃, more preferably 300-450℃, and most preferably 350-450℃; and / or

[0033] Heavy hourly space velocity is 1-30 h -1 Preferably 2-20h -1 More preferably 5-15h -1 .

[0034] According to the method of the first aspect, in step (5), the isomerization catalyst includes a support and a modified oxide, wherein the support includes a zeolite molecular sieve and a binder;

[0035] Preferably, the molecular sieve in the carrier has a mass fraction of 50-99%, and the binder has a mass fraction of 1-50%.

[0036] Preferably, the molecular sieve is a molecular sieve having MFI, FER, TON, and AEL structures, and the binder is alumina; and / or

[0037] 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.

[0038] A second aspect of the present invention provides a heavy hydrocarbon catalytic cracking apparatus, comprising:

[0039] 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.

[0040] 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 butene.

[0041] An etherification unit, connected to the separation unit, wherein at least a portion of the first olefin stream from the separation unit and optionally an externally sourced olefin are reacted with ethanol in the etherification unit to yield a recycled ethyl tert-butyl ether and a post-etherified olefin.

[0042] An ether catalytic conversion reactor is connected to the etherification unit and the separation unit, such that at least a portion of the recycled ethyl tert-butyl ether from the etherification unit enters the ether catalytic conversion reactor and optionally at least a portion of the post-etherified olefins enter the ether catalytic conversion reactor for reaction, and the resulting ether reaction products enter the separation unit for separation.

[0043] 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 isomerized product is returned to the etherification unit for further reaction.

[0044] According to the apparatus of the second 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;

[0045] 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.

[0046] Specifically, the method of this application has at least one of the following technical effects compared with the prior art:

[0047] 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.

[0048] 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.

[0049] 3. This invention produces carbon materials as 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 ethanol content in the products, thus achieving low-cost ethanol-to-low-carbon olefin conversion. It enables highly selective conversion of olefins and ethanol into low-carbon olefins, while solving the problem of excessively high methane yield from ethanol cracking, maximizing the production of ethylene and propylene, and improving the selectivity of methane and coke, achieving efficient utilization of ethanol and fossil resources. Attached Figure Description

[0050] Figure 1 A heavy hydrocarbon catalytic cracking reactor of the present invention is shown.

[0051] Figure 2 A device diagram of one specific embodiment of the present invention is shown.

[0052] Explanation of reference numerals in the attached figures:

[0053] 100. Catalytic cracking reactor; 200. Separation unit; 300. Etherification unit; 400. Isomerization unit; 500. Ether catalytic conversion reactor; 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. Ethanol; 109. Recycled ethyl tert-butyl ether; 110. Post-etherification olefins; 111. Non-olefin components; 112. Isomeric olefins; 113. Ether reaction products;

[0054] 1. Pre-lifting medium pipeline; 2. Variable diameter fluidized bed reactor; 3. Ethyl tert-butyl ether mixture pipeline; 4. Atomizing steam pipeline; 5. Cooling agent 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. Large oil and gas pipeline; 17. Fractionation, absorption-stabilization unit; 18. Dry gas pipeline Lines; 19. Liquefied gas pipeline; 20. Gasoline pipeline; 21. Diesel pipeline; 22. Oil slurry pipeline; 23. Gas separation unit; 24. Propylene pipeline; 25. Butene pipeline; 26. Isomerization unit; 27. Isoolefin pipeline; 28. Ethanol; 29. ​​Etherification unit; 30. Non-olefin component pipeline; 31. Post-etherified olefin; 32. Circulating ethyl tert-butyl ether pipeline; 33. Atomized steam; 34. Ether catalytic conversion reactor; 35. Cooling medium pipeline. Detailed Implementation

[0055] 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.

[0056] 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.

[0057] 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.

[0058] This invention provides a method for catalytic cracking of heavy hydrocarbons, comprising:

[0059] (1) The feedstock containing heavy hydrocarbons is reacted with the catalytic cracking catalyst in a catalytic cracking reactor to obtain catalytic cracking reaction products;

[0060] (2) The catalytic cracking reaction products enter the separation unit for separation to obtain a first olefin stream containing butene;

[0061] (3) At least a portion of the first olefin stream and optional externally sourced olefins enter the etherification unit and react with ethanol to give recycled ethyl tert-butyl ether and post-etherified olefins;

[0062] (4) At least a portion of the recycled ethyl tert-butyl ether enters the ether catalytic conversion reactor and optionally at least a portion of the ether post-olefins enter the ether catalytic conversion reactor to react, and the ether reaction products enter the separation unit.

[0063] (5) 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 isomerized product is returned to the etherification unit for further reaction.

[0064] 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 further converted into corresponding ether compounds as part of the olefin feedstock supplied to the etherification unit. 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, thereby maximizing the production of low-carbon olefins and carbon material feedstocks.

[0065] In one embodiment, 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.

[0066] In one embodiment, in step (1), the feed oil contains ethyl tert-butyl ether;

[0067] Preferably, the mass fraction of ethyl tert-butyl ether in the feedstock oil is not less than 20%, more preferably not less than 30%, more preferably not less than 50%, and most preferably not less than 80%.

[0068] In one embodiment, the catalytic cracking reaction conditions in step (1) include:

[0069] The reaction temperature is 460-750℃, preferably 480-700℃, more preferably 480-600℃, and most preferably 520-580℃;

[0070] Heavy hourly space velocity is 5-100 h -1 Preferably 10-70h -1 , more preferably 15-50h -1 The optimal time is 18-40 hours. -1 ;

[0071] The reaction time is 1-15 seconds, preferably 1.5-15 seconds, more preferably 2.0-15.0 seconds, and most preferably 5.0-10.0 seconds; and / or

[0072] The weight ratio of the agent to oil is 1-30, preferably 5-15, and more preferably 6-10.

[0073] 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.

[0074] 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 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.

[0075] In one embodiment, in step (1), the catalytic cracking catalyst includes zeolite, and the zeolite comprises 61-100 wt% mesoporous zeolite and 0-60 wt% macroporous zeolite by total weight, wherein the mesoporous zeolite has a high silica-alumina ratio of greater than 10, preferably greater than 50, and most preferably greater than 100.

[0076] Preferably, the mesoporous zeolite is selected from ZSM series zeolites and ZRP zeolites, and more preferably one or more of ZSM-5, ZSM-8 and ZSM-11; the macroporous zeolite is a Y series zeolite or a β series zeolite molecular sieve.

[0077] More preferably, the catalytic cracking catalyst includes a high-silica zeolite, which 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.

[0078] In one specific embodiment, the ZSM-type series molecular sieve is preferably selected from ZSM-5 or ZSM-11 molecular sieves, and the silicon-aluminum molar ratio of the molecular sieve, SiO2 / Al2O3, is 50-1000, preferably 80-800, and most preferably 100-800.

[0079] In one embodiment, in step (2), the catalytic cracking reaction product further includes a second olefin stream containing ethylene and propylene, gasoline, and catalytic wax oil;

[0080] Preferably, the catalytic wax oil has a 10% distillation point of not less than 250°C and a final distillation point of not more than 550°C; and / or

[0081] The total content of tricyclic and tetracyclic aromatic hydrocarbons in the catalytic wax oil is not less than 35% by weight, preferably not less than 40%, and most preferably not less than 45%. In one embodiment, the etherification reaction conditions in step (3) include:

[0082] The reaction temperature is 20-120℃, preferably 30-80℃, more preferably 35-75℃; and / or

[0083] The reaction pressure is 0-5.0 MPa, preferably 0.2-2.0 MPa, and more preferably 0.5-1.5 MPa.

[0084] In one embodiment, the isomerization reaction conditions in step (5) include:

[0085] The reaction temperature is 150-500℃, preferably 250-480℃, more preferably 300-450℃, and most preferably 350-450℃; and / or

[0086] Heavy hourly space velocity is 1-30 h -1 Preferably 2-20h -1 More preferably 5-15h -1 .

[0087] In one embodiment, in step (5), the isomerization catalyst includes a support and a modified oxide, wherein the support includes a zeolite molecular sieve and a binder;

[0088] Preferably, the molecular sieve in the carrier has a mass fraction of 50-99%, and the binder has a mass fraction of 1-50%.

[0089] Preferably, the molecular sieve is a molecular sieve having MFI, FER, TON, and AEL structures, and the binder is alumina; and / or

[0090] 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.

[0091] The present invention also provides a heavy hydrocarbon catalytic cracking device, comprising:

[0092] 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.

[0093] 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 butene.

[0094] An etherification unit, connected to the separation unit, wherein at least a portion of the first olefin stream from the separation unit and optionally an externally sourced olefin are reacted with ethanol in the etherification unit to yield a recycled ethyl tert-butyl ether and a post-etherified olefin.

[0095] An ether catalytic conversion reactor is connected to the etherification unit and the separation unit, such that at least a portion of the recycled ethyl tert-butyl ether from the etherification unit enters the ether catalytic conversion reactor and optionally at least a portion of the post-etherified olefins enter the ether catalytic conversion reactor for reaction, and the resulting ether reaction products enter the separation unit for separation.

[0096] 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 isomerized product is returned to the etherification unit for further reaction.

[0097] 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;

[0098] 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.

[0099] 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.

[0100] In one specific 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.

[0101] 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 oil 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 catalytic wax oil components can be separated from the slurry oil components.

[0102] In the etherification unit of this invention, olefin feedstock and ethanol 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.

[0103] For example, in the presence of an acid catalyst, olefin feedstock can be contacted with ethanol to undergo a condensation reaction, thereby generating the corresponding ether. Commonly used acid catalysts include sulfuric acid, phosphoric acid, and aluminum trichloride.

[0104] In the presence of a base catalyst, olefin feedstocks can be contacted with ethanol to undergo a condensation reaction, thereby generating the corresponding ethers. Commonly used base catalysts include sodium hydroxide, potassium hydroxide, and sodium carbonate.

[0105] In the presence of a metal catalyst, olefins can be contacted with ethanol to undergo a condensation reaction, thereby producing the corresponding ethers. Commonly used metal catalysts include copper, iron, and palladium.

[0106] Figure 1 A heavy hydrocarbon catalytic cracking reactor of the present invention is shown, comprising:

[0107] 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.

[0108] 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 butene, a second olefin stream containing ethylene and propylene, a gasoline stream, and catalytic wax oil.

[0109] Etherification unit 300, which is connected to separation unit 100, such that a first olefin stream from separation unit and optional externally sourced olefins react with ethanol in etherification unit to give recycled ethyl tert-butyl ether and post-etherified olefins.

[0110] 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.

[0111] 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;

[0112] Feedstock oil 101 containing heavy hydrocarbons is fed into catalytic cracking reactor 100 and reacted 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 butene, a second olefin stream 104 containing the target products ethylene and propylene, gasoline stream 105, and the target product catalytic wax oil 106. The first olefin stream 103 containing butene and optional externally sourced olefins 107 are fed into etherification unit 300 and reacted with ethanol 108 to obtain recycled ethyl tert-butyl ether 109 and post-etherified olefins 110. Post-etherified olefins 110 are fed into isomerization unit 400 for isomerization reaction, and the resulting isomerized olefins 112 are returned to the etherification unit for further reaction, while non-olefin components 111 are sent downstream. Recycled ethyl tert-butyl ether 109 is fed into ether catalytic conversion reactor 500 to obtain ether reaction product 113, which is then separated in separation unit 200.

[0113] Of course, the device also includes a regenerator for regenerating the catalyst. Figure 1 (Not shown), used to enable the catalyst to be recycled during the reaction. This will not be elaborated further here.

[0114] The following is combined with Figure 2 One specific implementation of the method of this application is described, but this does not limit the scope of this application.

[0115] The pre-lifting medium enters from the bottom of the variable-diameter fluidized bed reactor 2 (e.g., the reactor disclosed in Chinese Patent CN112569875A) via pipeline 1. The ethyl tert-butyl ether mixture, along with atomized steam from pipeline 4, is injected through pipeline 3 into the bottom of the first reaction zone 7 of the variable-diameter fluidized bed reactor 2 via nozzles. It contacts the regenerated catalyst from the regeneration inclined tube 15 within the reactor and moves upwards into the second reaction zone 8 of the variable-diameter fluidized bed reactor 2 to continue the reaction. The generated oil and gas, along with the deactivated catalyst, enters the cyclone separator in the settling tank 6 to separate the catalyst from the oil and gas. The reacted oil and gas enters the main oil and gas pipeline 16, while the catalyst fines are returned 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 2 through the regeneration inclined tube 15 for recycling.

[0116] 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 led out via pipeline 19 and separated into propylene via gas separation unit 23, which is then sent out via pipeline 24. Butene from pipeline 25 and ethanol from pipeline 28 are sent to the etherification unit 29. Unreacted etherified olefins are sent via pipeline 31 to the isomerization unit 26 to obtain isoolefins. The isoolefins are mixed with butene from pipeline 25 and returned to the etherification unit 29 via pipeline 27. The alkane components are sent to the downstream unit via the non-olefin components pipeline 30. The components containing ethyl tert-butyl ether are returned via pipeline 32 with other ethyl tert-butyl ethers from other sources to the ether catalytic conversion reactor 34 to react and increase the production of low-carbon olefins. Cooling medium from pipeline 35 is used to cool the reacted oil and gas. Gasoline, diesel, and slurry are led out via pipelines 20, 21, and 22, respectively.

[0117] 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.

[0118] Table 1. Properties of raw materials in examples and comparative examples.

[0119]

[0120] Example 1

[0121] according to Figure 2 The catalytic cracking unit process shown was tested (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, with 50% of the feedstock being ethyl tert-butyl ether, which entered the ether catalytic conversion reactor. TCC-1 was used as the catalyst. Target products such as ethylene, propylene, and catalytic wax oil (carbon material feedstock) were obtained. The reaction conditions and product distribution are listed in Table 2.

[0122] Comparative Example 1

[0123] according to Figure 2The catalytic cracking unit process shown was tested (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, with 50% of the feedstock being methyl tert-butyl ether (MTBE), which 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.

[0124] Example 2

[0125] according to Figure 2 The catalytic cracking unit process shown was tested (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. Ethyl tert-butyl ether, comprising 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 (carbon material feedstock) were obtained. The reaction conditions and product distribution are listed in Table 3.

[0126] Table 2. Reaction conditions and product distribution of the examples and comparative examples.

[0127]

[0128]

[0129] Table 3 Reaction conditions and product distribution in Example 2

[0130]

[0131]

[0132]

[0133] 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.

[0134] 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.

[0135] Furthermore, various different implementations of this application can be combined in any way, as long as they do not violate the spirit of this application, they should also be regarded as the content disclosed in this application.

[0136] The present application has been described above with reference to preferred embodiments; however, these embodiments are merely exemplary and illustrative. Various substitutions and modifications can be made to the present application based on these embodiments, all of which fall within the protection scope of the present application.

Claims

1. A method for catalytic cracking of heavy hydrocarbons, comprising: (1) The feedstock containing heavy hydrocarbons is reacted with the catalytic cracking catalyst in a catalytic cracking reactor to obtain catalytic cracking reaction products; (2) The catalytic cracking reaction products enter the separation unit for separation to obtain a first olefin stream containing butene; (3) At least a portion of the first olefin stream and optional externally sourced olefins enter the etherification unit and react with ethanol to give recycled ethyl tert-butyl ether and post-etherified olefins; (4) At least a portion of the recycled ethyl tert-butyl ether enters the ether catalytic conversion reactor and optionally at least a portion of the ether post-olefins enter the ether catalytic conversion reactor to react, and the ether reaction products enter the separation unit. (5) 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 isomerized product is returned to the etherification unit for further reaction.

2. The method according to claim 1, characterized in that, The heavy hydrocarbons are selected from petroleum hydrocarbons, mineral oils, or combinations thereof, wherein the petroleum hydrocarbons are 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 oils are selected from one or more of coal liquefaction oil, oil sands oil, and shale oil.

3. The method according to claim 1, characterized in that, In step (1), the feedstock oil contains ethyl tert-butyl ether; Preferably, the mass fraction of ethyl tert-butyl ether in the feedstock oil is not less than 20%, more preferably not less than 30%, more preferably not less than 50%, and most preferably not less than 80%.

4. The method according to claim 1, characterized in that, In step (1), the catalytic cracking reaction conditions include: The reaction temperature is 460-750℃, preferably 480-700℃, more preferably 480-600℃, and most preferably 520-580℃; Heavy hourly space velocity is 5-100 h -1 Preferably 10-70h -1 , more preferably 15-50h -1 The optimal time is 18-40 hours. -1 ; The reaction time is 1-15 seconds, preferably 1.5-15 seconds, more preferably 2.0-15.0 seconds, and most preferably 5.0-10.0 seconds; and / or The weight ratio of the agent to oil is 1-30, preferably 5-15, and more preferably 6-10.

5. The method according to claim 1, characterized in that, In step (1), the catalytic cracking catalyst includes zeolite, and by total weight of the zeolite, the zeolite includes 61-100 wt% mesoporous zeolite and 0-60 wt% macroporous zeolite, wherein the mesoporous zeolite has a high silica-alumina ratio of greater than 10, preferably greater than 50, and most preferably greater than 100. Preferably, the mesoporous zeolite is selected from ZSM series zeolites and ZRP zeolites, and more preferably one or more of ZSM-5, ZSM-8 and ZSM-11; the macroporous zeolite is a Y series zeolite or a β series zeolite molecular sieve. More preferably, the catalytic cracking catalyst includes a high-silica zeolite, which 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.

6. The method according to claim 1, characterized in that, In step (2), the catalytic cracking reaction products also include a second olefin stream containing ethylene and propylene, gasoline, and catalytic wax oil; Preferably, the catalytic wax oil has a 10% distillation point of not less than 250°C and a final distillation point of not more than 550°C; and / or The total content of tricyclic and tetracyclic aromatic hydrocarbons in the catalytic wax oil is not less than 35% by weight, preferably not less than 40%, and most preferably not less than 45%.

7. The method according to claim 1, characterized in that, In step (3), the etherification reaction conditions include: The reaction temperature is 20-120℃, preferably 30-80℃, more preferably 35-75℃; and / or The reaction pressure is 0-5.0 MPa, preferably 0.2-2.0 MPa, and more preferably 0.5-1.5 MPa.

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

9. The method according to claim 1, characterized in that, In step (5), the isomerization catalyst includes a support and a modified oxide, wherein the support includes a zeolite molecular sieve and a binder; Preferably, the molecular sieve in the carrier has a mass fraction of 50-99%, and the binder has a mass fraction of 1-50%. Preferably, the molecular sieve is a molecular sieve having MFI, FER, TON, and AEL structures, and the binder is alumina; and / or 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.

10. A heavy hydrocarbon catalytic cracking unit, 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 butene. An etherification unit, connected to the separation unit, wherein at least a portion of the first olefin stream from the separation unit and optionally an externally sourced olefin are reacted with ethanol in the etherification unit to yield a recycled ethyl tert-butyl ether and a post-etherified olefin. An ether catalytic conversion reactor is connected to the etherification unit and the separation unit, such that at least a portion of the recycled ethyl tert-butyl ether from the etherification unit enters the ether catalytic conversion reactor and optionally at least a portion of the post-etherified olefins enter the ether catalytic conversion reactor for reaction, and the resulting ether reaction products enter the separation unit for separation. 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 isomerized product is returned to the etherification unit for further reaction.

11. The apparatus according to claim 10, 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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