High-density rapid fluidized bed reactor and use method thereof
By designing a high-density fast fluidized bed reactor in methanol to olefin technology, using a high-cycle strength catalyst circulation and rapid gas-solid separation structure, the problems of side reactions and bed density reduction are solved, and high-efficiency ethylene and propylene yields are achieved.
Patent Information
- Application Number
- CN202311753070.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-19
- Publication Date
- 2025-06-20
AI Technical Summary
In the methanol-to-olefin technology, increasing the yield of ethylene and propylene is affected by the side reaction caused by the conversion of small-molecular olefins to large-molecular olefins. When increasing the apparent linear velocity of the fluidized bed reactor, the bed density and catalyst storage volume decrease, resulting in a decrease in methanol conversion.
A high-density fast fluidized bed reactor is designed. By establishing a catalyst cycle with high circulation strength between the catalyst retention area and the reaction area, the bed density of the reaction area is increased, and a structure directly connected to the conveying pipe is adopted to achieve rapid separation of product gas and catalyst and inhibit side reactions.
It is achieved to obtain high bed density under high apparent linear velocity conditions, improve raw material conversion rate, inhibit side reactions such as polymerization, alkylation, aromatization of small molecule olefins, and improve the yields of ethylene and propylene.
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Figure CN120169264A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to a high-density fast fluidized bed reactor and a method for using the same, belonging to the field of chemical catalysis. Background Art
[0002] Lower olefins such as ethylene and propylene are important basic organic chemical raw materials and the cornerstone of the modern chemical industry. Traditional production technologies strongly rely on petroleum resources. Therefore, it is of great strategic significance to use China's relatively rich coal resources to replace petroleum resources.
[0003] The technical routes for olefin production mainly include steam cracking of naphtha to olefins, methanol to olefins, propane dehydrogenation to propylene, alkane cracking to olefins, etc. Lower olefins are very reactive and prone to polymerization, alkylation, aromatization and other reactions, generating by-products and reducing the yield of lower olefins.
[0004] Methanol to olefins (MTO) technology aims at ethylene and propylene as target products. Methanol is converted into a mixture containing components such as ethylene, propylene, butene, pentene and alkanes under the action of a molecular sieve catalyst. In 2010, the Shenhua Baotou methanol to olefins plant using the DMTO technology developed by the Dalian Institute of Chemical Physics, Chinese Academy of Sciences was completed and put into production. This is the world's first industrial application of MTO technology. As of 2023, 16 sets of DMTO industrial plants have been put into production, with a total low-carbon olefin production capacity of about 9.3 million tons / year. Taking the DMTO technology as an example, the carbon-based selectivity of ethylene and propylene is about 80% wt, and the selectivity of butene and pentene is about 15% wt.
[0005] Improving the yield of ethylene and propylene is a major goal in the progress of olefin production technology. Summary of the Invention
[0006] Methanol to olefins technology uses SAPO molecular sieve catalysts. According to the hydrocarbon pool mechanism, methanol is converted into products such as ethylene and propylene through the aromatic cycle or olefin cycle in the molecular sieve catalyst. The main reactions include:
[0007] CH3OH → C2H4 + C3H6 (1)
[0008] C2H4 + CH3OH → C3H6 (2)
[0009] C3H6 + CH3OH → C4H8 (3)
[0010] C4H8 + CH3OH → C5H 10 (4)
[0011] Reactions (1) and (2) produce ethylene and propylene. Reactions (2), (3), and (4) show that small-molecule olefins are relatively reactive and are further converted into large-molecule olefins, thereby reducing the yields of ethylene and propylene.
[0012] The methanol-to-olefins technology uses a fluidized-bed reactor. Improving the production capacity of a single reactor and suppressing the conversion of small-molecule olefins into large-molecule olefins are the core objectives in the development of methanol-to-olefins reactors. An effective way to increase the production capacity of a single reactor is to increase the superficial linear velocity of the fluidized-bed reactor to achieve the purpose of increasing the feedstock input. Additionally, increasing the superficial linear velocity of the fluidized-bed reactor and reducing the residence time of the product gas in the reactor can effectively inhibit the formation of large-molecule olefins. However, when increasing the superficial linear velocity, the bed density in the reaction zone of the fluidized-bed reactor usually decreases significantly, and the catalyst inventory also decreases significantly, which in turn leads to a decrease in the methanol conversion rate. That is, there is a negative correlation between the feedstock input and the bed density in the fluidized-bed reaction zone.
[0013] To solve the above technical problems, the present application discloses a high-density fast fluidized-bed reactor, which achieves a high bed density under high superficial linear velocity conditions, improves the feedstock conversion rate, and simultaneously inhibits side reactions such as polymerization, alkylation, and aromatization of small-molecule olefins.
[0014] According to the first aspect of the present application, a high-density fast fluidized-bed reactor is provided.
[0015] A high-density fast fluidized-bed reactor, the high-density fast fluidized-bed reactor includes a reactor outer shell, a reactor inner shell, a delivery pipe, a first gas-solid separation device, and a second gas-solid separation device;
[0016] The reactor inner shell is located at the lower part of the reactor outer shell;
[0017] The delivery pipe is located in the central area of the upper-middle part of the high-density fast fluidized-bed reactor;
[0018] The area enclosed by the reactor inner shell is the reaction zone;
[0019] The bottom end of the delivery pipe is communicated with the top end of the reaction zone;
[0020] The annular area enclosed by the reactor outer shell and the reactor inner shell is the catalyst residence zone;
[0021] The bottom of the reaction zone is communicated with the bottom of the catalyst residence zone;
[0022] The area enclosed by the reactor outer shell and the delivery pipe is the gas-solid separation zone;
[0023] The catalyst residence zone is communicated with the gas-solid separation zone and is located below the gas-solid separation zone;
[0024] The first gas-solid separation device and the second gas-solid separation device are both located in the gas-solid separation zone;
[0025] The upper opening of the conveying pipe is connected to the inlet of the first gas-solid separation device;
[0026] The catalyst outlet of the first gas-solid separation device is located at the lower part of the gas-solid separation zone.
[0027] Optionally, the inlet of the second gas-solid separation device is located in the gas-solid separation zone, and the catalyst outlet of the second gas-solid separation device is located at the lower part of the gas-solid separation zone.
[0028] Optionally, the first gas-solid separation device and the second gas-solid separation device independently adopt one or more groups of gas-solid cyclone separators, and each group of gas-solid cyclone separators includes a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.
[0029] Optionally, the high-density fast fluidized bed reactor includes a reactor gas collection chamber and a product gas conveying pipe;
[0030] The reactor gas collection chamber is located at the top of the high-density fast fluidized bed reactor;
[0031] The product gas conveying pipe is connected to the top of the reactor gas collection chamber;
[0032] The gas outlet of the first gas-solid separation device and the gas outlet of the second gas-solid separation device are both connected to the reactor gas collection chamber.
[0033] Optionally, the high-density fast fluidized bed reactor includes a catalyst distribution pipe, a fluidizing steam distributor, a raw material distributor, a catalyst extraction pipe, and a catalyst input pipe;
[0034] The catalyst distribution pipe passes through the inner shell of the reactor to connect the catalyst residence zone and the reaction zone;
[0035] The fluidizing steam distributor is located at the bottom of the catalyst residence zone;
[0036] The raw material distributor is located at the bottom of the reaction zone;
[0037] The catalyst extraction pipe passes through the outer shell of the reactor and is located at the lower part of the catalyst residence zone;
[0038] The catalyst input pipe passes through the outer shell of the reactor and is located at the lower part of the gas-solid separation zone.
[0039] Optionally, the lower surface of the catalyst distribution pipe is provided with openings.
[0040] As a preferred embodiment, the high-density fast fluidized bed reactor comprises: a reactor outer shell, a reactor inner shell, a conveying pipe, a raw material distributor, a first gas-solid separation device, a gas collecting chamber, a fluidizing steam distributor, a catalyst distribution pipe, a second gas-solid separation device, a product gas conveying pipe, a catalyst input pipe, and a catalyst extraction pipe.
[0041] The area enclosed by the reactor inner shell is the reaction zone, and the annular area enclosed by the reactor outer shell and the reactor inner shell is the catalyst residence zone. The bottom of the reaction zone is communicated with the bottom of the catalyst residence zone. The area enclosed by the reactor outer shell and the conveying pipe is the gas-solid separation zone. The catalyst residence zone is communicated with the gas-solid separation zone and is located below the gas-solid separation zone.
[0042] The raw material distributor is located at the bottom of the reaction zone. The conveying pipe is located in the central area of the middle and upper parts of the high-density fast fluidized bed reactor. The bottom end of the conveying pipe is connected to the top end of the reaction zone, and the upper part of the conveying pipe is connected to the inlet of the first gas-solid separation device.
[0043] The first gas-solid separation device is located in the gas-solid separation zone. The gas outlet of the first gas-solid separation device is connected to the gas collecting chamber, and the catalyst outlet of the first gas-solid separation device is located in the lower part of the gas-solid separation zone.
[0044] The fluidizing steam distributor is located at the bottom of the catalyst residence zone.
[0045] The catalyst distribution pipe passes through the reactor inner shell to communicate the catalyst residence zone and the reaction zone, and the lower surface of the catalyst distribution pipe is provided with openings.
[0046] The second gas-solid separation device is located in the gas-solid separation zone. The inlet of the second gas-solid separation device is located in the gas-solid separation zone. The gas outlet of the second gas-solid separation device is connected to the gas collecting chamber, and the catalyst outlet of the second gas-solid separation device is located in the lower part of the gas-solid separation zone.
[0047] The gas collecting chamber is located at the top of the high-density fast fluidized bed reactor, and the product gas conveying pipe is connected to the top of the gas collecting chamber.
[0048] The catalyst input pipe passes through the reactor outer shell and is located in the lower part of the gas-solid separation zone.
[0049] The catalyst extraction pipe passes through the reactor outer shell and is located in the lower part of the catalyst residence zone.
[0050] According to the second aspect of the present application, a method for using the above-mentioned high-density fast fluidized bed reactor is provided.
[0051] The method for using the above-mentioned high-density fast fluidized bed reactor includes:
[0052] (S-1) The catalyst enters the gas-solid separation zone through the catalyst input pipe and then enters the catalyst residence zone;
[0053] (S-2) The gasified raw material enters the reaction zone from the raw material distributor, contacts the catalyst to generate product gas, and the product gas carries the catalyst through the transfer pipe into the first gas-solid separation device. After gas-solid separation, the catalyst enters the catalyst residence zone;
[0054] (S-3) Steam enters the catalyst residence zone from the fluidizing steam distributor. The steam carries a small amount of catalyst and enters the second gas-solid separation device in the gas-solid separation zone. After gas-solid separation, the catalyst returns to the catalyst residence zone;
[0055] (S-4) The catalyst in the catalyst residence zone enters the reaction zone through the catalyst distribution pipe; the catalyst in the catalyst residence zone enters the bottom of the reaction zone through the bottom of the catalyst residence zone;
[0056] (S-5) The catalyst in the catalyst residence zone is discharged through the catalyst extraction pipe.
[0057] Optionally, the product gas in step (S-2) and the steam in step (S-3) enter the reactor gas collection chamber and enter the downstream section through the product gas transfer pipe.
[0058] Optionally, the process operating conditions of the reaction zone are: the gas superficial linear velocity is 1.5 - 7.0 m / s, the temperature is 350 - 700 °C, the pressure is 50 - 500 kPa, the bed density is 100 - 500 kg / m 3 , and the reaction contact time is 0.5 - 4 s.
[0059] Optionally, the process operating conditions of the catalyst residence zone are: the gas superficial linear velocity is 0.02 - 0.2 m / s, the temperature is 350 - 700 °C, and the bed density is 500 - 900 kg / m 3 .
[0060] Optionally, the catalyst circulation intensity flowing from the catalyst residence zone to the reaction zone is 500 - 1000 kg / (m 2 ·s).
[0061] Optionally, the product gas is a product gas containing olefins.
[0062] Optionally, the raw material includes methanol and / or dimethyl ether.
[0063] When the raw material includes methanol and / or dimethyl ether, the catalyst is a SAPO molecular sieve.
[0064] Optionally, the SAPO molecular sieve is selected from SAPO-34 and / or SAPO-18 molecular sieves
[0065] Optionally, the raw material includes C3+ hydrocarbons.
[0066] Specifically, the raw material is mixed C4 or naphtha.
[0067] When the raw material includes C3+ hydrocarbons, the catalyst is ZSM-5 molecular sieve.
[0068] Among them, C3+ hydrocarbons refer to hydrocarbons with the number of carbon atoms in the molecule greater than or equal to 3.
[0069] As a preferred embodiment, the method for using the high-density fast fluidized bed reactor includes:
[0070] a. The catalyst enters the gas-solid separation zone through the catalyst input pipe and then enters the catalyst residence zone;
[0071] b. The gasified raw material enters the reaction zone from the raw material distributor, contacts with the catalyst, generates product gas containing olefins, and the product gas carries the catalyst through the conveying pipe into the first gas-solid separation device. After gas-solid separation, the product gas enters the gas collection chamber, and the catalyst enters the catalyst residence zone;
[0072] c. Steam enters the catalyst residence zone from the fluidizing steam distributor. The steam carries a small amount of catalyst from the catalyst residence zone into the second gas-solid separation device in the gas-solid separation zone. After gas-solid separation, the steam enters the gas collection chamber, and the catalyst returns to the catalyst residence zone;
[0073] d. The product gas and steam enter the downstream section through the product gas conveying pipe;
[0074] f. The catalyst in the catalyst residence zone enters the reaction zone through the catalyst distribution pipe; the catalyst in the catalyst residence zone enters the bottom of the reaction zone from the bottom of the catalyst residence zone;
[0075] g. The catalyst in the catalyst residence zone is discharged through the catalyst extraction pipe.
[0076] The beneficial effects that this application can produce include:
[0077] (1) The high-density fast fluidized bed reactor provided by this application mainly includes a reaction zone, a catalyst residence zone and a gas-solid separation zone. The catalyst circulation intensity flowing from the catalyst residence zone to the reaction zone is as high as 500-1000 kg / (m 2 ·s), thereby increasing the bed density of the reaction zone, achieving a high bed density under high apparent linear velocity conditions, and overcoming the negative correlation between the raw material feed rate and the bed density of the fluidized bed reaction zone.
[0078] (2) The high-density fast fluidized bed reactor provided by this application adopts a structure in which the first gas-solid separation device is directly connected to the conveying pipe, achieving rapid separation of the product gas and the catalyst, greatly shortening the gas-solid contact time, and suppressing side reactions.
[0079] (3) The high-density fast fluidized bed reactor provided by this application is suitable for the molecular sieve catalytic reaction process with small molecule olefins as the target product. Brief Description of the Drawings
[0080] Figure 1 It is a schematic diagram of the high-density fast fluidized bed reactor of an embodiment of this application.
[0081] Figure 1 The descriptions of the reference numerals in the drawings are as follows:
[0082] 1 - Reactor outer shell 2 - Reactor inner shell 3 - Conveying pipe
[0083] 4 - Feed distributor 5 - First gas-solid separation device 6 - Gas collection chamber
[0084] 7 - Fluidizing steam distributor 8 - Catalyst distribution pipe 9 - Second gas-solid separation device
[0085] 10 - Product gas conveying pipe 11 - Catalyst input pipe 12 - Catalyst extraction pipe. Detailed Description of the Embodiment
[0086] The following describes this application in detail with reference to the embodiments, but this application is not limited to these embodiments.
[0087] Unless otherwise specified, the raw materials and catalysts in the embodiments of this application are all purchased through commercial channels.
[0088] In a specific embodiment, the schematic diagram of the high-density fast fluidized bed reactor described in this application is as Figure 1 shown, mainly including a reaction zone (A), a catalyst residence zone (B), and a gas-solid separation zone (C), which are described as follows:
[0089] 1. The high-density fast fluidized bed reactor comprises: a reactor outer shell (1), a reactor inner shell (2), a conveying pipe (3), a raw material distributor (4), a first gas-solid separation device (5), a gas collecting chamber (6), a fluidizing steam distributor (7), a catalyst distribution pipe (8), a second gas-solid separation device (9), a product gas conveying pipe (10), a catalyst input pipe (11) and a catalyst extraction pipe (12); the area enclosed by the reactor inner shell (2) is the reaction zone (A), the annular area enclosed by the reactor outer shell (1) and the reactor inner shell (2) is the catalyst residence zone (B), the bottom of the reaction zone (A) is communicated with the bottom of the catalyst residence zone (B), the area enclosed by the reactor outer shell (1) and the conveying pipe (3) is the gas-solid separation zone (C), the catalyst residence zone (B) is communicated with the gas-solid separation zone (C) and is located below the gas-solid separation zone (C).
[0090] 2. The raw material distributor (4) is located at the bottom of the reaction zone (A), the conveying pipe (3) is located in the central area of the middle and upper parts of the high-density fast fluidized bed reactor, the bottom end of the conveying pipe (3) is connected to the top end of the reaction zone (A), and the upper part of the conveying pipe (3) is connected to the inlet of the first gas-solid separation device (5); the first gas-solid separation device (5) is located in the gas-solid separation zone (C), the gas outlet of the first gas-solid separation device (5) is connected to the gas collecting chamber (6), and the catalyst outlet of the first gas-solid separation device (5) is located in the lower part of the gas-solid separation zone (C); the fluidizing steam distributor (7) is located at the bottom of the catalyst residence zone (B); the catalyst distribution pipe (8) passes through the reactor inner shell (2) to communicate the catalyst residence zone (B) and the reaction zone (A), and the lower surface of the catalyst distribution pipe (8) is provided with openings; the second gas-solid separation device (9) is located in the gas-solid separation zone (C), the inlet of the second gas-solid separation device (9) is located in the gas-solid separation zone (C), the gas outlet of the second gas-solid separation device (9) is connected to the gas collecting chamber (6), and the catalyst outlet of the second gas-solid separation device (9) is located in the lower part of the gas-solid separation zone (C); the gas collecting chamber (6) is located at the top of the high-density fast fluidized bed reactor, the product gas conveying pipe (10) is connected to the top of the gas collecting chamber (6), the catalyst input pipe (11) passes through the reactor outer shell (1) and is located in the lower part of the gas-solid separation zone (C); the catalyst extraction pipe (12) passes through the reactor outer shell (1) and is located in the lower part of the catalyst residence zone (B).
[0091] Specifically, the first gas-solid separation device (5) adopts multiple groups of gas-solid cyclone separators, and each group of gas-solid cyclone separators comprises a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.
[0092] Specifically, the second gas-solid separation device (9) adopts multiple groups of gas-solid cyclone separators, and each group of gas-solid cyclone separators includes a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.
[0093] In a specific embodiment, a method for using a high-density fast fluidized bed reactor according to the present application includes the following steps:
[0094] a. The catalyst enters the gas-solid separation zone (C) through the catalyst input pipe (11), and then enters the catalyst residence zone (B);
[0095] b. The gasified raw material enters the reaction zone (A) from the raw material distributor (4), contacts with the catalyst to generate product gas containing olefins, the product gas carries the catalyst and enters the first gas-solid separation device (5) through the conveying pipe (3). After gas-solid separation, the product gas enters the gas collection chamber (6), and the catalyst enters the catalyst residence zone (B);
[0096] c. Steam enters the catalyst residence zone (B) from the fluidizing steam distributor (7), and the steam carries a small amount of catalyst and enters the second gas-solid separation device (9) in the gas-solid separation zone (C) from the catalyst residence zone (B). After gas-solid separation, the steam enters the gas collection chamber (6), and the catalyst returns to the catalyst residence zone (B);
[0097] d. The product gas and steam enter the downstream section through the product gas conveying pipe (10);
[0098] e. The catalyst in the catalyst residence zone (B) enters the reaction zone (A) through the catalyst distribution pipe (8); the catalyst in the catalyst residence zone (B) enters the bottom of the reaction zone (A) from the bottom of the catalyst residence zone (B);
[0099] f. The catalyst in the catalyst residence zone (B) is discharged through the catalyst extraction pipe (12).
[0100] For the method described in the present application, the calculation methods of the single-pass conversion rate of the raw material and the product selectivity are as follows:
[0101] Single-pass conversion rate of raw material = (1 - mass flow rate of raw material in product gas / mass flow rate of raw material feed) × 100%
[0102] Selectivity of "target product" = mass flow rate of "target product" in product gas / (mass flow rate of product gas - mass flow rate of raw material in product gas - mass flow rate of water in product gas) × 100%
[0103] Example 1
[0104] This embodiment uses Figure 1 the device shown.
[0105] In this embodiment, the raw material is methanol. The catalyst is a SAPO-34 molecular sieve catalyst. The process operating conditions in the reaction zone (A) are as follows: the superficial gas linear velocity is 7.0 m / s, the temperature is 450 °C, the pressure is 50 kPa, and the bed density is 100 kg / m 3 , and the reaction contact time is 0.8 s. The process operating conditions in the catalyst residence zone (B) are as follows: the superficial gas linear velocity is 0.2 m / s, the temperature is 450 °C, and the bed density is 500 kg / m 3 . The catalyst circulation intensity flowing from the catalyst residence zone (B) to the reaction zone (A) is 1000 kg / (m 2 ·s).
[0106] In Example 1 of this embodiment, the single-pass conversion rate of methanol is 99.9%, and the product composition is 50% wt ethylene, 41% wt propylene, and 9% wt of other components. The other components are methane, ethane, propane, butane, butene, C5+ hydrocarbons, hydrogen, CO, CO2, and coke, etc.
[0107] Example 2
[0108] This embodiment uses the device shown in Figure 1 .
[0109] In this embodiment, the raw material is methanol. The catalyst is a SAPO-18 molecular sieve catalyst. The process operating conditions in the reaction zone (A) are as follows: the superficial gas linear velocity is 5.0 m / s, the temperature is 360 °C, the pressure is 100 kPa, and the bed density is 200 kg / m 3 , and the reaction contact time is 1.1 s. The process operating conditions in the catalyst residence zone (B) are as follows: the superficial gas linear velocity is 0.1 m / s, the temperature is 360 °C, and the bed density is 740 kg / m 3 . The catalyst circulation intensity flowing from the catalyst residence zone (B) to the reaction zone (A) is 860 kg / (m 2 ·s).
[0110] In Example 2 of this embodiment, the single-pass conversion rate of methanol is 99.6%, and the product composition is 38% wt ethylene, 51% wt propylene, and 11% wt of other components. The other components are methane, ethane, propane, butane, butene, C5+ hydrocarbons, hydrogen, CO, CO2, and coke, etc.
[0111] Example 3
[0112] This embodiment uses the device shown in Figure 1 .
[0113] In this embodiment, the raw material is dimethyl ether. The catalyst is a SAPO-34 molecular sieve catalyst. The process operating conditions in the reaction zone (A) are as follows: the superficial gas linear velocity is 3.0 m / s, the temperature is 410 °C, the pressure is 180 kPa, and the bed density is 270 kg / m 3 , and the reaction contact time is 1.8 s. The process operating conditions in the catalyst residence zone (B) are as follows: the superficial gas linear velocity is 0.08 m / s, the temperature is 410 °C, and the bed density is 620 kg / m 3 . The catalyst circulation intensity flowing from the catalyst residence zone (B) to the reaction zone (A) is 710 kg / (m 2 ·s).
[0114] In Example 3 of this embodiment, the single-pass conversion rate of methanol is 99.8%, and the product composition is 44% wt ethylene, 46% wt propylene, and 10% wt of other components. The other components are methane, ethane, propane, butane, butene, C5+ hydrocarbons, hydrogen, CO, CO2, and coke, etc.
[0115] Example 4
[0116] This embodiment uses the device shown in Figure 1 .
[0117] In this embodiment, the raw material is mixed C4, which contains 34% wt butane, 63% wt butene, 1% wt pentane, and 2% wt pentene. The catalyst is a ZSM-5 molecular sieve catalyst. The process operating conditions in the reaction zone (A) are as follows: the superficial gas linear velocity is 2.0 m / s, the temperature is 690 °C, the pressure is 500 kPa, and the bed density is 390 kg / m 3 , and the reaction contact time is 2.7 s. The process operating conditions in the catalyst residence zone (B) are as follows: the superficial gas linear velocity is 0.05 m / s, the temperature is 690 °C, and the bed density is 830 kg / m 3 . The catalyst circulation intensity flowing from the catalyst residence zone (B) to the reaction zone (A) is 660 kg / (m 2 ·s).
[0118] In Example 4 of this embodiment, the single-pass conversion rate of mixed C4 is 77%, and the product composition is 17% wt ethylene, 65% wt propylene, and 18% wt of other components. The other components are methane, ethane, propane, butane, butene, C5+ hydrocarbons, hydrogen, CO, CO2, and coke, etc.
[0119] Example 5
[0120] This embodiment uses the device shown in Figure 1 .
[0121] In this embodiment, the raw material is naphtha. The catalyst is a ZSM-5 molecular sieve catalyst. The process operating conditions in the reaction zone (A) are as follows: the apparent gas linear velocity is 1.5 m / s, the temperature is 650 °C, the pressure is 300 kPa, and the bed density is 500 kg / m 3 , and the reaction contact time is 3.7 s. The process operating conditions in the catalyst residence zone (B) are as follows: the apparent gas linear velocity is 0.02 m / s, the temperature is 650 °C, and the bed density is 900 kg / m 3 . The catalyst circulation intensity flowing from the catalyst residence zone (B) to the reaction zone (A) is 500 kg / (m 2 ·s).
[0122] In Example 5 of this embodiment, the single-pass conversion rate of naphtha is 83%, and the product composition is 12 wt% ethylene, 56 wt% propylene, 19 wt% butene, and 13 wt% other components. The other components are methane, ethane, propane, butane, hydrogen, CO, CO2, and coke, etc.
[0123] As described above, these are only several embodiments of the present application and do not impose any form of limitation on the present application. Although the present application is disclosed with preferred embodiments as above, it is not intended to limit the present application. Any person skilled in the art, without departing from the scope of the technical solution of the present application, making some changes or modifications using the disclosed technical content is equivalent to equivalent implementation cases and all fall within the scope of the technical solution.
Claims
1. A high-density fast fluidized bed reactor, characterized in that, The high-density fast fluidized bed reactor includes a reactor outer shell, a reactor inner shell, a delivery pipe, a first gas-solid separation device, and a second gas-solid separation device; The reactor inner shell is located in the lower part of the reactor outer shell; The delivery pipe is located in the central area in the upper-middle part of the high-density fast fluidized bed reactor; The area enclosed by the reactor inner shell is the reaction zone; The bottom end of the delivery pipe communicates with the top end of the reaction zone; The annular area enclosed by the reactor outer shell and the reactor inner shell is the catalyst residence zone; The bottom of the reaction zone communicates with the bottom of the catalyst residence zone; The area enclosed by the reactor outer shell and the delivery pipe is the gas-solid separation zone; The catalyst residence zone communicates with the gas-solid separation zone and is located below the gas-solid separation zone; Both the first gas-solid separation device and the second gas-solid separation device are located in the gas-solid separation zone; The upper opening of the delivery pipe is connected to the inlet of the first gas-solid separation device; The catalyst outlet of the first gas-solid separation device is located in the lower part of the gas-solid separation zone.
2. The high-density fast fluidized bed reactor according to claim 1, characterized in that, The inlet of the second gas-solid separation device is located in the gas-solid separation zone, and the catalyst outlet of the second gas-solid separation device is located in the lower part of the gas-solid separation zone; Preferably, the first gas-solid separation device and the second gas-solid separation device each independently employ one or more groups of gas-solid cyclone separators, and each group of gas-solid cyclone separators includes a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.
3. The high-density fast fluidized bed reactor according to claim 1, characterized in that, The high-density fast fluidized bed reactor includes a reactor gas collection chamber and a product gas delivery pipe; The reactor gas collection chamber is located at the top of the high-density fast fluidized bed reactor; The product gas delivery pipe is connected to the top of the reactor gas collection chamber; The gas outlet of the first gas-solid separation device and the gas outlet of the second gas-solid separation device are both connected to the reactor gas collection chamber.
4. The high-density fast fluidized bed reactor according to claim 1, characterized in that, The high-density fast fluidized bed reactor includes a catalyst distribution pipe, a fluidizing steam distributor, a raw material distributor, a catalyst extraction pipe, and a catalyst input pipe; The catalyst distribution pipe passes through the reactor inner shell to communicate the catalyst residence zone and the reaction zone; The fluidizing steam distributor is located at the bottom of the catalyst residence zone; The raw material distributor is located at the bottom of the reaction zone; The catalyst extraction pipe passes through the reactor outer shell and is located in the lower part of the catalyst residence zone; The catalyst input pipe passes through the reactor outer shell and is located in the lower part of the gas-solid separation zone; Preferably, the lower surface of the catalyst distribution pipe is perforated.
5. A method for using the high-density fast fluidized bed reactor according to any one of claims 1-4, characterized in that, The method includes: (S-1) The catalyst enters the gas-solid separation zone through the catalyst input pipe and then enters the catalyst residence zone; (S-2) The gasified raw material enters the reaction zone from the raw material distributor, contacts the catalyst to generate product gas, and the product gas carries the catalyst through the delivery pipe into the first gas-solid separation device. After gas-solid separation, the catalyst enters the catalyst residence zone; (S-3) Steam enters the catalyst residence zone from the fluidizing steam distributor, and the steam carries a small amount of catalyst from the catalyst residence zone into the second gas-solid separation device in the gas-solid separation zone. After gas-solid separation, the catalyst returns to the catalyst residence zone; (S-4) The catalyst in the catalyst residence zone enters the reaction zone through the catalyst distribution pipe; the catalyst in the catalyst residence zone enters the bottom of the reaction zone through the bottom of the catalyst residence zone. (S-5) The catalyst in the catalyst residence zone is discharged through the catalyst extraction pipe.
6. The method according to claim 5, characterized in that, The product gas in step (S-2) and the steam in step (S-3) enter the reactor gas collection chamber and enter the downstream section through the product gas transfer pipe.
7. The method according to claim 5, wherein The process operating conditions of the reaction zone are as follows: the apparent gas linear velocity is 1.5 - 7.0 m / s, the temperature is 350 - 700 °C, the pressure is 50 - 500 kPa, and the bed density is 100 - 500 kg / m 3 , and the reaction contact time is 0.5 - 4 s; Preferably, the process operating conditions in the catalyst residence zone are as follows: the superficial gas linear velocity is 0.02 - 0.2 m / s, the temperature is 350 - 700 °C, and the bed density is 500 - 900 kg / m 3 ; Preferably, the catalyst circulation intensity flowing from the catalyst residence zone to the reaction zone is 500 - 1000 kg / (m 2 ·s).
8. The method according to claim 5, wherein The product gas is a product gas containing olefins.
9. The method according to claim 5, wherein The raw materials include methanol and / or dimethyl ether; Preferably, the catalyst is SAPO molecular sieve.
10. The method according to claim 5, wherein The raw materials include C3+ hydrocarbons; Preferably, the catalyst is ZSM-5 molecular sieve.