Low-carbon olefin production device and production method

Abstract

The invention discloses a low-carbon olefin production device and a production method, which can realize high-selectivity conversion of olefin and ethanol into low-carbon olefin, solve the problem of overhigh yield of ethanol cracking methane, furthest obtain ethylene and propylene, improve the selectivity of methane and coke and realize efficient utilization of ethanol and fossil resources.

Description

A low-carbon olefin production apparatus and production method Technical Field

[0001] This application pertains to the field of petroleum processing, specifically relating to a low-carbon olefin production apparatus and production method. 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] 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. There are very few reports on the use of ethyl tert-butyl ether to produce low-carbon olefins such as ethylene and propylene. Summary of the Invention

[0006] One objective of this application is to provide a method for maximizing the production of low-carbon olefins from ethyl tert-butyl ether, which can convert ethyl tert-butyl ether into low-carbon olefins, improve the yield and selectivity of ethylene and propylene, reduce the yield of methane, and minimize the ethanol content in the product, thereby achieving low-cost ethanol-to-low-carbon olefin conversion.

[0007] A first aspect of the present invention provides a low-carbon olefin production apparatus, comprising:

[0008] The catalytic conversion unit is used to react ethyl tert-butyl ether with a catalytic conversion catalyst to obtain the catalytic conversion reaction product, including a catalytic conversion reactor, a settling tank, and a regenerator;

[0009] A separation unit, connected to the catalytic conversion unit, is used to separate the catalytic conversion reaction products obtained from the catalytic conversion unit, yielding ethylene, propylene, a first-cycle olefin stream containing butene, and a C5-containing olefin stream. + The second-cycle olefin stream;

[0010] An etherification unit is connected to the separation unit, wherein at least a portion of the first recycled olefin stream enters the etherification unit and contacts ethanol to obtain recycled ethyl tert-butyl ether, post-etherified olefin and non-olefin streams;

[0011] At least a portion of the recycled ethyl tert-butyl ether, at least a portion of the post-ether olefins, and / or at least a portion of the second recycled olefin stream are returned to the catalytic conversion reactor for catalytic conversion reaction.

[0012] According to the low-carbon olefin production apparatus of the first aspect, the apparatus further includes:

[0013] An isomerization unit is connected to the etherification unit. At least a portion of the post-etherified olefins and / or olefins from other sources enter the isomerization unit and come into contact with the isomerization catalyst to undergo an isomerization reaction, resulting in isomerized olefins. The isomerized olefins are then returned to the etherification unit for an etherification reaction.

[0014] According to the low-carbon olefin production apparatus of the first aspect, the catalytic conversion reactor is selected from any one and / or a combination of two or more reactor types, namely, fixed-bed, moving-bed and fluidized-bed reactors;

[0015] Preferably, the fixed bed reactor consists of two or more reactors connected in series or parallel, and the fluidized bed reactor consists of one or more reactors connected in series or parallel, such as equal diameter riser, constant linear velocity riser, variable diameter riser, fluidized bed, composite reactor composed of equal diameter riser and fluidized bed, upward conveyor line, and downward conveyor line.

[0016] A second aspect of the present invention provides a method for producing low-carbon olefins, the method using the low-carbon olefin production apparatus of the first aspect, comprising:

[0017] (1) Methyl tert-butyl ether is brought into contact with the catalytic conversion catalyst in the catalytic conversion reactor to carry out the catalytic conversion reaction, and the catalytic conversion reaction product is obtained. The catalytic conversion catalyst after the reaction is settled by the settler and then entered the regenerator for regeneration and returned to the catalytic conversion reactor.

[0018] (2) Separate the products of the catalytic conversion reaction to obtain ethylene, propylene, a first-cycle olefin stream containing butene, and a C5-containing olefin stream. + The second-cycle olefin stream;

[0019] (3) At least a portion of the first cycle olefin stream enters the etherification unit and is contacted with ethanol under etherification conditions to obtain a cycle ethyl tert-butyl ether, post-etherified olefin and non-olefin streams;

[0020] (4) At least a portion of the recycled ethyl tert-butyl ether, at least a portion of the non-olefin stream and / or at least a portion of the second recycled olefin stream are returned to the catalytic conversion reactor for catalytic conversion reaction.

[0021] According to the production method of the second aspect, the method further includes:

[0022] (5) At least a portion of the etherified olefins and / or other source olefins obtained in step (3) enter the isomerization unit and come into contact with the isomerization catalyst to undergo an isomerization reaction to obtain isomerized olefins, and the isomerized olefins are returned to the etherification unit for etherification reaction.

[0023] According to the production method of the second aspect, in step (1), the catalytic conversion reaction conditions include:

[0024] The reaction temperature is 460-750℃, preferably 500-700℃, more preferably 520-700℃, and most preferably 550-680℃;

[0025] 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

[0026] The weight ratio of the agent to oil is 1-50, preferably 5-40, and more preferably 6-30.

[0027] According to the production method of the second aspect, in step (1), the catalytic conversion catalyst is selected from amorphous silica-alumina catalyst and / or zeolite catalyst, and the zeolite in the zeolite catalyst is selected from Y-type series macroporous molecular sieves, β-type macroporous zeolite molecular sieves, ZSM-type series mesoporous molecular sieves, and SAPO-type series small-pore molecular sieves.

[0028] Preferably, the zeolite in the catalytic conversion catalyst is selected from ZSM-type molecular sieves, more preferably from ZSM-5, ZSM-11 molecular sieves and hierarchical porous molecular sieves, wherein the silicon-aluminum molar ratio SiO2 / AlO3 of the molecular sieve is 50-1000, more preferably 80-800, and most preferably 100-800;

[0029] More preferably, the ZSM-type molecular sieve in the catalytic conversion catalyst is a high-silica zeolite containing phosphorus and transition metals, and its anhydrous chemical expression, based on the mass of the oxide, 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 element M.

[0030] According to the production method of the second aspect, the catalytic conversion reaction product obtained in step (1) has the following characteristics:

[0031] The product contains no more than about 5.0% methane by mass, preferably no more than about 2.0%, and most preferably no more than 1.0%.

[0032] The mass ratio of ethylene to methane is not less than 4.0, preferably not less than about 8.0, and most preferably not less than 12.0;

[0033] The mass fraction ratio of propylene to propane in the product is not less than 10, preferably not less than 15, and most preferably not less than 30.

[0034] According to the production method of the second aspect, in step (3), the etherification conditions include:

[0035] The reaction temperature is 20-120℃, preferably 30-80℃, more preferably 35-75℃; and / or

[0036] The reaction pressure is 0-5.0 MPa, preferably 0.2-2.0 MPa, and more preferably 0.5-1.5 MPa.

[0037] According to the production method of the second aspect, in step (5), the isomerization reaction conditions include:

[0038] The reaction temperature is 150-500℃, preferably 250-480℃, more preferably 300-450℃, and most preferably 350-450℃; and / or

[0039] Heavy hourly space velocity is 1-30 h -1 Preferably 2-20h -1 More preferably 5-15h-1 .

[0040] According to the production method of the second aspect, in step (5), the isomerization catalyst comprises a support and a modified oxide, wherein:

[0041] The carrier comprises a zeolite molecular sieve and a binder. Preferably, the carrier comprises 50-99% by mass of molecular sieve and 1-50% by mass of binder. The molecular sieve is a molecular sieve with MFI, FER, TON and AEL structures, and the binder is alumina.

[0042] The modified oxide is a polyol, and the mass ratio of the modified oxide to the carrier is preferably 0.01 to 0.3:1. Preferably, the polyol is a C2 to C7 polyol, and more preferably one or more of ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, glycerol, trimethylolethane, pentaerythritol, xylitol and sorbitol.

[0043] Specifically, the method of this application has at least one of the following technical effects compared with the prior art:

[0044] 1. Ethyl tert-butyl ether is 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 wood, organic waste, etc.), thereby achieving low-cost production of low-carbon olefins.

[0045] 2. Biomass is the process by which plants fix carbon dioxide using solar energy and store it in the form of chemical energy. It can be used to produce alcohols, further obtain ethyl tert-butyl ether, and finally convert into low-carbon olefins, thus realizing the recycling of carbon resources.

[0046] 3. It can achieve 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, thus achieving efficient utilization of ethanol and fossil resources. Attached Figure Description

[0047] Figure 1 shows a schematic diagram of an apparatus for preparing low-carbon olefins according to the present invention.

[0048] Figure 2 shows a schematic diagram of an apparatus for preparing low-carbon olefins according to the present invention.

[0049] Figure 3 shows a diagram of the apparatus for preparing low-carbon olefins according to an embodiment of the present invention.

[0050] Figure 4 shows a diagram of the apparatus for the comparative preparation of low-carbon olefins according to the present invention.

[0051] Explanation of reference numerals in the attached figures:

[0052] 100. Catalytic conversion reactor; 200. Separation unit; 300. Etherification unit; 400. Isomerization unit; 101. Ethyl tert-butyl ether; 102. Catalytic conversion reaction product; 103. Ethylene; 104. Propylene; 105. First recycled olefin stream; 106. Second recycled olefin stream; 107. Externally sourced olefins; 108. Ethanol; 109. Recycled ethyl tert-butyl ether; 110. Post-etherification olefins; 111. Non-olefin components; 112. Isomerized olefins;

[0053] 1. Pre-lifting medium pipeline; 2. Variable diameter fluidized bed reactor; 3. Methyl tert-butyl ether stream; 4. Atomized steam; 5. Coolant stream; 6. Settler; 7. First reaction zone; 8. Second reaction zone; 9. Stripping section; 10. Stripping steam; 11. Regenerator inclined tube; 12. Regenerator; 13. Main air pipeline; 14. Flue gas pipeline; 15. Regeneration inclined tube; 16. Large oil and gas stream pipeline; 17. Fractionation, absorption-stabilization unit; 18. Dry gas stream Pipelines; 19. Liquefied gas pipeline; 20. Gasoline pipeline; 21. Diesel pipeline; 22. Heavy oil pipeline; 23. Gas separation unit; 24. Propylene pipeline; 25. Other olefins pipeline; 26. Etherification unit; 27. Post-etherification olefins pipeline; 28. Alcohols pipeline (e.g., methanol); 29. ​​Non-olefin components pipeline; 30. Isomerization unit; 31. Ethers pipeline; 32. Ethers pipeline. 2. Variable diameter fluidized bed reactor; 3. Methyl tert-butyl ether stream; 4. Atomized steam; 5. Coolant stream; 6. Settler; 7. First reaction zone; 8. Second reaction zone; 9. Stripping section; 10. Stripping steam; 11. Regenerator inclined tube; 12. Regenerator; 13. Main air pipeline; 14. Flue gas pipeline; 15. Regenerator inclined tube; 16. Large oil and gas stream pipeline; 17. Fractionation, absorption-stabilization unit; 18. Dry gas stream pipeline; 19. Liquefied gas stream pipeline Line; 20. Gasoline feed line; 21. Diesel feed line; 22. Heavy oil feed line; 23. Gas separation unit; 24. Propylene feed line; 25. Other olefin feed line; 26. Etherification unit; 27. Olefin feed line; 28. Alcohol feed line (e.g., methanol); 29. ​​Post-etherification non-olefin component feed line; 30. Isomerization unit; 31. Ether feed return line; 32. Post-etherification olefin return line; 33. Return feed line. Detailed Implementation

[0054] 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.

[0055] 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.

[0056] 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.

[0057] This invention provides a low-carbon olefin production apparatus, comprising:

[0058] The catalytic conversion unit is used to react ethyl tert-butyl ether with a catalytic conversion catalyst to obtain the catalytic conversion reaction product, including a catalytic conversion reactor, a settling tank, and a regenerator;

[0059] A separation unit, connected to the catalytic conversion unit, is used to separate the catalytic conversion reaction products obtained from the catalytic conversion unit, yielding ethylene, propylene, a first-cycle olefin stream containing butene, and a C5-containing olefin stream. + The second-cycle olefin stream;

[0060] An etherification unit is connected to the separation unit, wherein at least a portion of the first recycled olefin stream enters the etherification unit and contacts ethanol to obtain recycled ethyl tert-butyl ether, post-etherified olefin and non-olefin streams;

[0061] At least a portion of the recycled ethyl tert-butyl ether, at least a portion of the post-ether olefins, and / or at least a portion of the second recycled olefin stream are returned to the catalytic conversion reactor for catalytic conversion reaction.

[0062] In one embodiment, the device further includes:

[0063] An isomerization unit is connected to the etherification unit. At least a portion of the post-etherified olefins and / or olefins from other sources enter the isomerization unit and come into contact with the isomerization catalyst to undergo an isomerization reaction, resulting in isomerized olefins. The isomerized olefins are then returned to the etherification unit for an etherification reaction.

[0064] In one embodiment, the catalytic conversion reactor is selected from any one and / or a combination of two or more reactor types, namely fixed bed, moving bed and fluidized bed reactors;

[0065] Preferably, the fixed bed reactor consists of two or more reactors connected in series or parallel, and the fluidized bed reactor consists of one or more reactors connected in series or parallel, such as equal diameter riser, constant linear velocity riser, variable diameter riser, fluidized bed, composite reactor composed of equal diameter riser and fluidized bed, upward conveyor line, and downward conveyor line.

[0066] According to this application, the catalytic conversion 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 a composite reactor composed of constant diameter riser and fluidized bed, upward conveying line, and downward conveying line.

[0067] In one specific embodiment, the catalytic conversion 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] The present invention also provides a method for producing low-carbon olefins, the method using the aforementioned low-carbon olefin production apparatus, comprising:

[0074] (1) Methyl tert-butyl ether is brought into contact with the catalytic conversion catalyst in the catalytic conversion reactor to carry out the catalytic conversion reaction, and the catalytic conversion reaction product is obtained. The catalytic conversion catalyst after the reaction is settled by the settler and then entered the regenerator for regeneration and returned to the catalytic conversion reactor.

[0075] (2) Separate the products of the catalytic conversion reaction to obtain ethylene, propylene, a first-cycle olefin stream containing butene, and a C5-containing olefin stream. + The second-cycle olefin stream;

[0076] (3) At least a portion of the first cycle olefin stream enters the etherification unit and is contacted with ethanol under etherification conditions to obtain a cycle ethyl tert-butyl ether, post-etherified olefin and non-olefin streams;

[0077] (4) At least a portion of the recycled ethyl tert-butyl ether, at least a portion of the non-olefin stream and / or at least a portion of the second recycled olefin stream are returned to the catalytic conversion reactor for catalytic conversion reaction.

[0078] In one embodiment, the method further includes:

[0079] (5) At least a portion of the etherified olefins and / or other source olefins obtained in step (3) enter the isomerization unit and come into contact with the isomerization catalyst to undergo an isomerization reaction to obtain isomerized olefins, and the isomerized olefins are returned to the etherification unit for etherification reaction.

[0080] In this application, low-carbon olefins refer to ethylene and propylene. The method and apparatus of this application can produce ethylene and propylene with relatively few other byproducts such as methane and propane.

[0081] The method of this application may include the following steps: 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-type olefins to ethers via condensation reactions with alcohols is lower, resulting in a higher proportion of normal-type 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, by producing low-carbon olefins such as ethylene and propylene from ethyl tert-butyl ether, can maximize the production of low-carbon olefins.

[0082] In one embodiment, the catalytic conversion reaction conditions in step (1) include:

[0083] The reaction temperature is 460-750℃, preferably 500-700℃, more preferably 520-700℃, and most preferably 550-680℃;

[0084] 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

[0085] The weight ratio of the agent to oil is 1-50, preferably 5-40, and more preferably 6-30.

[0086] 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.

[0087] The inventors of this application have discovered that when the temperature is below 200°C, ethers are converted into alcohols and olefins, with a low selectivity for low-carbon olefins (the total amount of 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 (the total amount of ethylene and propylene) in the product 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.

[0088] In one embodiment, in step (1), the catalytic conversion catalyst is selected from amorphous silica-alumina catalysts and / or zeolite catalysts. The zeolite in the zeolite catalyst is selected from Y-type macroporous molecular sieves, β-type macroporous zeolite molecular sieves, ZSM-type mesoporous molecular sieves, and SAPO-type microporous molecular sieves. SAPO-type molecular sieve catalysts include, but are not limited to, SAPO-34 and SAPO-18 molecular sieve catalysts.

[0089] Preferably, the zeolite in the catalytic conversion catalyst is selected from ZSM-type molecular sieves, more preferably from ZSM-5, ZSM-11 molecular sieves and hierarchical porous molecular sieves, wherein the silicon-aluminum molar ratio SiO2 / AlO3 of the molecular sieve is 50-1000, more preferably 80-800, and most preferably 100-800;

[0090] More preferably, the ZSM-type molecular sieve in the catalytic conversion catalyst is a high-silica zeolite containing phosphorus and transition metals, and its anhydrous chemical expression, based on the mass of the oxide, 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 element M.

[0091] 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.

[0092] 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.

[0093] In one embodiment, the catalytic conversion product obtained in step (1) has the following characteristics:

[0094] The product contains no more than about 5.0% methane by mass, preferably no more than about 2.0%, and most preferably no more than 1.0%.

[0095] The mass ratio of ethylene to methane is not less than 4.0, preferably not less than about 8.0, and most preferably not less than 12.0;

[0096] The mass fraction ratio of propylene to propane in the product is not less than 10, preferably not less than 15, and most preferably not less than 30.

[0097] In one embodiment, step (3) includes the following etherification conditions:

[0098] The reaction temperature is 20-120℃, preferably 30-80℃, more preferably 35-75℃; and / or

[0099] The reaction pressure is 0-5.0 MPa, preferably 0.2-2.0 MPa, and more preferably 0.5-1.5 MPa.

[0100] In one embodiment, the isomerization reaction conditions in step (5) include:

[0101] The reaction temperature is 150-500℃, preferably 250-480℃, more preferably 300-450℃, and most preferably 350-450℃; and / or

[0102] Heavy hourly space velocity is 1-30 h -1Preferably 2-20h -1 More preferably 5-15h -1 .

[0103] In one embodiment, in step (5), the isomerization catalyst comprises a support and a modified oxide, wherein:

[0104] The carrier comprises a zeolite molecular sieve and a binder. Preferably, the carrier comprises 50-99% by mass of molecular sieve and 1-50% by mass of binder. The molecular sieve is a molecular sieve with MFI, FER, TON and AEL structures, and the binder is alumina.

[0105] The modified oxide is a polyol, and the mass ratio of the modified oxide to the carrier is preferably 0.01 to 0.3:1. Preferably, the polyol is a C2 to C7 polyol, and more preferably one or more of ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, glycerol, trimethylolethane, pentaerythritol, xylitol and sorbitol.

[0106] Figure 1 shows a schematic diagram of a low-carbon olefin production apparatus according to the present invention, including:

[0107] Catalytic conversion reactor 100 is used to react ethyl tert-butyl ether with a catalytic conversion catalyst in the catalytic conversion reactor to obtain the catalytic conversion reaction product;

[0108] Separation unit 200, connected to catalytic conversion reactor 100, is used to separate the catalytic conversion reaction products from the reactor, yielding ethylene, propylene, a first recycled olefin stream containing butene, and a C5-containing olefin stream. + The second-cycle olefin stream;

[0109] Etherification unit 300, which is connected to separation unit 200, such that a first circulating olefin stream from separation unit reacts with ethanol in etherification unit to obtain circulating ethyl tert-butyl ether and post-etherified olefin;

[0110] The etherification unit 300 is also connected to the catalytic conversion reactor 100, so that the recycled ethyl tert-butyl ether and the etherified olefin from the etherification unit enter the catalytic conversion reactor for reaction.

[0111] Ethyl tert-butyl ether 101 is fed into catalytic conversion reactor 100 and reacted with catalytic conversion catalyst to obtain catalytic conversion product 102. Catalytic conversion product 102 is then separated in separation unit 200 to obtain ethylene 103 (the target product), propylene 104, a first recycled olefin stream 105 (containing butene), and a C5... +First cycle olefin stream 106 containing olefins; first cycle olefin stream 105 containing butene, containing C5 + The first recycled olefin stream 106 and optional externally sourced olefins 107 enter the etherification unit 300 and react with ethanol 108 to produce recycled ethyl tert-butyl ether 109 and post-etherified olefins 110; recycled ethyl tert-butyl ether 109 and post-etherified olefins 110 are returned to the catalytic conversion reactor for further reaction, while non-olefin components 111 are sent downstream.

[0112] Figure 2 shows a schematic diagram of a low-carbon olefin production apparatus according to the present invention, including:

[0113] Catalytic conversion reactor 100 is used to react ethyl tert-butyl ether with a catalytic conversion catalyst in the catalytic conversion reactor to obtain the catalytic conversion reaction product;

[0114] Separation unit 200, connected to catalytic conversion reactor 100, is used to separate the catalytic conversion reaction products from the reactor, yielding ethylene, propylene, a first recycled olefin stream containing butene, and a C5-containing olefin stream. + The second-cycle olefin stream;

[0115] Etherification unit 300, which is connected to separation unit 200, such that a first circulating olefin stream from separation unit reacts with ethanol in etherification unit to obtain circulating ethyl tert-butyl ether and post-etherified olefin;

[0116] Isomerization unit 400 is connected to etherification unit 300, such that at least a portion of the post-etherified olefin enters the isomerization unit to react with the isomerization catalyst, and the resulting isomerization product is returned to etherification unit 300 for further reaction.

[0117] The etherification unit 300 is also connected to the catalytic conversion reactor 100, so that the recycled ethyl tert-butyl ether from the etherification unit and at least a portion of the etherified olefins enter the catalytic conversion reactor for reaction.

[0118] Ethyl tert-butyl ether 101 is fed into catalytic conversion reactor 100 and reacted with catalytic conversion catalyst to obtain catalytic conversion product 102. Catalytic conversion product 102 is then separated in separation unit 200 to obtain ethylene 103 (the target product), propylene 104, a first recycled olefin stream 105 (containing butene), and a C5... + First cycle olefin stream 106 containing olefins; first cycle olefin stream 105 containing butene, containing C5 +The first recycled olefin stream 106 and optional externally sourced olefins 107 enter the etherification unit 300 and react with ethanol 108 to obtain recycled ethyl tert-butyl ether 109 and post-etherified olefins 110. At least a portion of the post-etherified olefins 110 enters the isomerization unit 400 for isomerization, and the resulting isomerized olefins 112 are returned to the etherification unit 300 for further reaction. The recycled ethyl tert-butyl ether 109 is returned to the catalytic conversion reactor for further reaction, and at least a portion of the post-etherified olefins are returned to the catalytic conversion reactor via the post-etherified olefin return line 113 for further reaction. The non-olefin component 111 is sent downstream. A specific embodiment of the method of this application is described below with reference to Figure 3, but this does not limit the scope of this application.

[0119] 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.

[0120] The reaction oil and gas pass through the large oil and gas pipeline 16 and enter the fractionation, absorption-stabilization unit 17. The separated dry gas is drawn out through pipeline 18 and separated to obtain ethylene. The liquefied gas is drawn out through pipeline 19 and separated into propylene through the gas separation unit 23 and sent out through pipeline 24. Other olefins are sent to the etherification unit 26 through pipeline 25, gasoline from pipeline 20 and ethanol from pipeline 28. The ethyl tert-butyl ether obtained from etherification is returned to reactor 2 through pipelines 31 and 33 to react. The olefins that have not reacted are returned to reactor 2 through pipelines 32 and 33 to increase the production of low carbon olefins or sent to the isomerization unit 30 through pipeline 27. The isomerized olefin stream is returned to the etherification unit 26 through pipeline 34. The non-olefin components that have not reacted are sent to the downstream unit through pipeline 29.

[0121] Example

[0122] 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 oil used in the embodiments and comparative examples are as follows: the catalyst used in the embodiments and comparative examples is a commercially available catalytic conversion catalyst with the brand name TCC-1, manufactured by Sinopec Catalyst Qilu Branch; the isomerization catalyst used in the embodiments is a commercially available catalyst with the brand name FI-15, manufactured by Sinopec Petrochemical Research Institute; the catalyst used in the etherification unit in the embodiments is CN101245255B, which is consistent with the catalyst used in the embodiments.

[0123] Table 1. Properties of raw materials in examples and comparative examples.

[0124]

[0125]

[0126] Comparative Example 1

[0127] The experiment was conducted according to the flow chart shown in Figure 4. The specific structure of the variable-diameter fluidized bed reactor is shown in Example 1 of CN112569875A. The feedstock was ethyl tert-butyl ether, and TCC-1 was used as the catalyst. The experiment was carried out on a variable-diameter fluidized bed reactor catalytic cracking unit. The unit did not include an etherification unit, and other olefin components and gasoline components obtained from liquefied gas separation were not etherified. The target products, ethylene and propylene, were obtained. The reaction conditions and product distribution are listed in Table 2.

[0128] Comparative Example 2

[0129] The experiment was conducted using the variable-diameter fluidized bed reactor (specifically, as shown in Example 1 of CN112569875A) according to the flow chart in Figure 4. The feedstock was ethyl tert-butyl ether, and TCC-1 was used as the catalyst. The experiment was carried out on a variable-diameter fluidized bed reactor catalytic cracking unit, which did not include an etherification unit. Other olefin components and gasoline components obtained from liquefied petroleum gas separation were not etherified. The target products, ethylene and propylene, were obtained. The reaction conditions and product distribution are listed in Table 2. The difference from Example 1 is that the reaction temperature was 450°C.

[0130] Example 1

[0131] The experiment was conducted according to the flow chart shown in Figure 3. The specific structure of the variable-diameter fluidized bed reactor is as described in Example 1 of CN112569875A. The feedstock was ethyl tert-butyl ether, and TCC-1 was used as the catalyst. The experiment was carried out on a variable-diameter fluidized bed reactor catalytic cracking unit. The target products, ethylene and propylene, were obtained. The reaction conditions and product distribution are listed in Table 2. The difference from Example 1 is that after the isobutylene product underwent etherification and isomerization, the ethers were returned to the variable-diameter fluidized bed reactor catalytic cracking unit.

[0132] Table 2 Reaction conditions and product distribution of the examples

[0133]

[0134]

[0135] The results above show that the method of the present invention can achieve 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, thus achieving efficient utilization of ethanol and fossil resources.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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 low-carbon olefin production apparatus, comprising: The catalytic conversion unit is used to react ethyl tert-butyl ether with a catalytic conversion catalyst to obtain the catalytic conversion reaction product, including a catalytic conversion reactor, a settling tank, and a regenerator; A separation unit, connected to the catalytic conversion unit, is used to separate the catalytic conversion reaction products obtained from the catalytic conversion unit, yielding ethylene, propylene, a first-cycle olefin stream containing butene, and a C5-containing olefin stream. + The second-cycle olefin stream; An etherification unit is connected to the separation unit. At least a portion of the first recycled olefin stream enters the etherification unit and contacts ethanol to obtain recycled ethyl tert-butyl ether, post-etherified olefins, and non-olefin streams. At least a portion of the recycled ethyl tert-butyl ether, at least a portion of the post-etherified olefins, and / or at least a portion of the second recycled olefin stream are returned to the catalytic conversion reactor for catalytic conversion reaction.

2. The low-carbon olefin production apparatus according to claim 1, characterized in that, The apparatus further includes an isomerization unit connected to the etherification unit, wherein at least a portion of the post-etherified olefins and / or olefins from other sources enter the isomerization unit and come into contact with the isomerization catalyst to undergo an isomerization reaction to obtain isomerized olefins, and the isomerized olefins are returned to the etherification unit for an etherification reaction.

3. The low-carbon olefin production apparatus according to claim 1 or 2, characterized in that, The catalytic conversion reactor is selected from any one and / or a combination of two or more reactor types, including 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, and the fluidized bed reactor is selected from one or more reactors connected in series or parallel, including constant diameter riser, constant linear velocity riser, variable diameter riser, fluidized bed, and a composite reactor composed of constant diameter riser and fluidized bed, upward conveying line, and downward conveying line.

4. A method for producing low-carbon olefins, the method using the low-carbon olefin production apparatus according to any one of claims 1 to 3, comprising: (1) Methyl tert-butyl ether is brought into contact with a catalytic conversion catalyst in a catalytic conversion reactor to carry out a catalytic conversion reaction, and the catalytic conversion reaction product is obtained. The spent catalytic conversion catalyst is settled in a settling tank and then regenerated in a regenerator before being returned to the catalytic conversion reactor; (2) The catalytic conversion reaction product is separated to obtain ethylene, propylene, a first circulating olefin stream containing butene, and a C5-containing olefin stream. + The second-cycle olefin stream; (3) At least a portion of the first cycle olefin stream enters the etherification unit and is contacted with ethanol under etherification conditions to obtain a cycle ethyl tert-butyl ether, post-etherified olefin and non-olefin streams; (4) At least a portion of the recycled ethyl tert-butyl ether, at least a portion of the non-olefin stream and / or at least a portion of the second recycled olefin stream are returned to the catalytic conversion reactor for catalytic conversion reaction.

5. The production method according to claim 4, characterized in that, The method further includes: (5) at least a portion of the etherified olefins and / or other source olefins obtained in step (3) enter the isomerization unit and contact with the isomerization catalyst to undergo an isomerization reaction to obtain isomerized olefins, and the isomerized olefins are returned to the etherification unit for etherification reaction.

6. The production method according to claim 4 or 5, characterized in that, In step (1), the catalytic conversion 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 agent-oil weight ratio of 1-50, preferably 5-40, and more preferably 6-30.

7. The production method according to claim 4 or 5, characterized in that, In step (1), the catalytic conversion catalyst is selected from amorphous silica-alumina catalysts and / or zeolite catalysts. The zeolite in the zeolite catalyst is selected from Y-type macroporous molecular sieves, β-type macroporous zeolite molecular sieves, ZSM-type mesoporous molecular sieves, and SAPO-type microporous molecular sieves. Preferably, the zeolite in the catalytic conversion catalyst is selected from ZSM-type molecular sieves, more preferably from ZSM-5, ZSM-11 molecular sieves, and hierarchical molecular sieves, wherein the silica-alumina molar ratio SiO2 / AlO3 of the molecular sieve is 50-1000, preferably 80-800, and most preferably 100-800. More preferably, the ZSM-type molecular sieve in the catalytic conversion catalyst 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 element M.

8. The production method according to claim 4 or 5, characterized in that, In step (1), the obtained catalytic conversion reaction product has the following characteristics: the mass percentage of methane in the product is not greater than about 5.0%, preferably not greater than about 2.0%, and most preferably not greater than 1.0%; the mass ratio of ethylene to methane is not less than 4.0, preferably not less than about 8.0, and most preferably not less than 12.0; the mass fraction ratio of propylene to propane in the product is not less than 10, preferably not less than 15, and most preferably not less than 30.

9. The production method according to claim 4 or 5, characterized in that, In step (3), the etherification conditions include: a reaction temperature of 20-120°C, preferably 30-80°C, more preferably 35-75°C; and / or a reaction pressure of 0-5.0 MPa, preferably 0.2-2.0 MPa, more preferably 0.5-1.5 MPa.

10. The production method according to claim 5, characterized in that, In step (5), 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 .

11. The production method according to claim 5, characterized in that, In step (5), the isomerization catalyst comprises a support and a modified oxide, wherein: the support comprises a zeolite molecular sieve and a binder, preferably, the support comprises 50-99% by mass of molecular sieve and 1-50% by mass of binder; the molecular sieve is a molecular sieve having an MFI structure, FER structure, TON structure and AEL structure, and the binder is alumina; the modified oxide is a polyol, and the mass ratio of the modified oxide to the support is preferably 0.01-0.3:1, preferably, the polyol is a C2-C7 polyol, more preferably one or more of ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, glycerol, trimethylolethane, pentaerythritol, xylitol and sorbitol.

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