Vortex Layer Reactor, Device and Application

Description

TECHNICAL FIELD

[0001] The present application relates to a fluidized bed reactor, a device for preparing light olefins from an oxygen-containing compound, and use thereof, and belongs to the technical field of chemical equipment.BACKGROUND

[0002] Methanol-to-olefin technology (MTO) mainly includes DMTO (methanol-to-olefin) technology of Dalian Institute of Chemical Physics, Chinese Academy of Sciences and MTO technology of UOP Company of the United States. In 2010, the Shenhua Baotou methanol-to-olefin plant using DMTO technology was completed and put into operation. This is the world's first industrial application of MTO technology. As of the end of 2019, 14 DMTO industrial plants have been put into production, with a total production capacity of about 8 million tons of light olefins per year.

[0003] In recent years, DMTO technology has been further developed, and a new generation of DMTO catalyst with better performance have gradually begun industrial applications, creating higher benefits for DMTO plants. The new generation of DMTO catalyst has higher methanol processing capacity and light olefin selectivity. It is difficult for the existing DMTO industrial devices to take full advantage of the advantages of the new generation of DMTO catalyst. Therefore, it is necessary to develop a DMTO device and production method that can meet the needs of a new generation of DMTO catalyst with high methanol processing capacity and high selectivity of light olefins.

[0004] WO 2015 / 081489 A1 discloses a method for raising the light olefin yield in process of preparing a light olefin from an improved oxygen-containing compound, which primarily solves the problems in the prior art of the difficult control to catalyst carbon deposition and carbon content uniformity and low light olefin yield. While the present invention aims at providing a fluidized bed reactor, a device containing the reactor and a method for preparing light olefin, achieving reduced heat transfer to reaction zone, control over temperature, and thus direct use of regenerated catalyst in the preparation of light olefin as needed.SUMMARY

[0005] The invention is set out in the appended set of claims.

[0006] Possible beneficial effects of the present application: (1) A major characteristic of a DMTO catalyst is that the light olefin selectivity in a methanol conversion process increases with the increase of a coke content in the catalyst. The light olefins mentioned in the present application refer to ethylene and propylene. The applicants have found through research that main factors affecting the activity of a DMTO catalyst and the selectivity for light olefins include coke content, coke content distribution, and coke species in the catalyst. Under the same average coke content in catalysts, the narrower the coke content distribution, the higher the selectivity and activity of light olefins. Coke species in a catalyst may include polymethyl aromatic hydrocarbons, polymethyl cycloalkanes, and the like, where polymethylbenzene and polymethylnaphthalene can promote the formation of ethylene. Therefore, the control of the coke content, coke content distribution, and coke species in a catalyst is the key to control the activity of the DMTO catalyst and improve the selectivity of light olefins. The fluidized bed reactor in the present application is provided with a coke control zone, and the coke control zone is divided into a plurality of subzones by the baffles arranged in the coke control zone, such that a catalyst flows along the subzones one by one. A residence time distribution of the catalyst is controlled through the subzones to be narrow, such as to control a coke content distribution in the catalyst and make the coke content distribution narrow. Moreover, the coke content and coke species are also controlled. Therefore, the activity of the DMTO catalyst and the selectivity for light olefins are improved. (2) In the method of the present application, a catalyst can only flow from an upstream subzone to a downstream subzone through the catalyst circulation holes on the baffles in the coke control zone, such that an average residence time of a catalyst in the coke control zone can be controlled to control a coke content in the catalyst; and the structure of n coke control zone subzones is adopted to control a residence time distribution of a catalyst (the residence time distribution is similar to n serially-connected completely-mixed tank reactors), and a catalyst with a narrow coke content distribution is obtained. (3) The present application can control the conversion and generation of coke species in a catalyst. On the one hand, inactive large-molecule coke species remaining in a regenerated catalyst are converted into small-molecule coke species; and on the other hand, a coke control raw material can also enter the catalyst to generate highly-active small-molecule coke species, and the small-molecule coke species are mainly polymethylbenzene and polymethylnaphthalene, which can improve the selectivity for ethylene. (4) With the method for on-line modification of a DMTO catalyst through a coke control reaction in the present application, a coke controlled catalyst with high coke content, narrow coke content distribution, and polymethylbenzene and polymethylnaphthalene as main coke species components can be obtained, that is, the regenerated catalyst with low selectivity for light olefins is converted into a coke controlled catalyst with high selectivity for light olefins. (5) The regenerated catalyst in the present application can be directly used in the process of preparing light olefins from an oxygen-containing compound without a coke control treatment, and in this case, the selectivity for light olefins in an obtained product gas is 80 wt% to 83 wt%. When the regenerated catalyst in the present application is subjected to a coke control treatment and then used in the process of preparing light olefins from an oxygen-containing compound, the selectivity for light olefins in an obtained product gas is 93 wt% to 96 wt%. (6) In the method of the present application, a high-temperature regenerated catalyst from the regenerator is first cooled in the coke control zone and then enters the reaction zone, that is, there is no local high-temperature zone in the reaction zone; and thus the raw material with an oxygen-containing compound has a low coking rate. (7) The reaction zone of the fluidized bed reactor in the present application includes a fluidized bed reactor cooler, which can accurately control a temperature of the reaction zone. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 is a schematic diagram of a DMTO device for preparing light olefins from an oxygen-containing compound according to an embodiment of the present application; and FIG. 2 is a schematic diagram of a cross section of a coke control zone of the fluidized bed reactor according to an embodiment of the present application. List of reference numerals:

[0008] 1 represents a fluidized bed reactor; 1-1 represents a main shell; 1-2 represents a reaction zone distributor; 1-3 represents a fluidized bed reactor cooler; 1-4 represents a coke control zone distributor; 1-5 represents a baffle; 1-6 represents a first gas-solid separation unit; 1-7 represents a coke controlled catalyst delivery pipe; 1-8 represents a coke control zone gas delivery pipe; 1-9 represents a second gas-solid separation unit; 1-10 represents a first gas collection chamber; 1-11 represents a product gas delivery pipe; 1-12 represents a first stripper; 1-13 represents a spent catalyst slide valve; 1-14 represents a spent catalyst delivery pipe; 2 represents a fluidized bed regenerator; 2-1 represents a regenerator shell; 2-2 represents a regeneration zone distributor; 2-3 represents a third gas-solid separation unit; 2-4 represents a second gas collection chamber; 2-5 represents a flue gas delivery pipe; 2-6 represents a second stripper; 2-7 represents a regenerator cooler; 2-8 represents a regenerated catalyst slide valve; and 2-9 represents a regenerated catalyst delivery pipe. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0009] The present application will be described in detail below with reference to examples, but the present application is not limited to these examples.

[0010] Possible embodiments are described below.

[0011] In order to improve the performance of a DMTO catalyst, the present application provides a method for on-line modification of a DMTO catalyst through a coke control reaction, including the following steps: a) a regenerated catalyst is delivered to a coke control zone; b) a coke control raw material including hydrogen, methane, ethane, ethylene, propane, propylene, butane, butene, pentane, pentene, hexane, hexene, methanol, ethanol, and water is delivered to a coke control reactor; (c) the coke control raw material contacts and reacts with the regenerated catalyst in the coke control reactor, such that the coke control raw material is coked on the regenerated catalyst, where a coked catalyst is called a coke controlled catalyst; a coke content in the coke controlled catalyst is 4 wt% to 9 wt%; coke species include polymethylbenzene and polymethylnaphthalene, and a total mass of the polymethylbenzene and the polymethylnaphthalene accounts for greater than or equal to 70 wt% of a total mass of coke; and a mass of coke species with a molecular weight greater than 184 accounts for less than or equal to 25 wt% of the total mass of coke; and d) the coke controlled catalyst is delivered to a methanol conversion reactor.

[0012] The regenerated catalyst may be a DMTO catalyst with a coke content of less than or equal to 3 wt%, and an active component of the DMTO catalyst may be an SAPO molecular sieve.

[0013] The coke control raw material may be composed of 0 wt% to 20 wt% of hydrogen, 0 wt% to 50 wt% of methane, 0 wt% to 50 wt% of ethane, 0 wt% to 20 wt% of ethylene, 0 wt% to 50 wt% of propane, 0 wt% to 20 wt% of propylene, 0 wt% to 90 wt% of butane, 0 wt% to 90 wt% of butene, 0 wt% to 90 wt% of pentane, 0 wt% to 90 wt% of pentene, 0 wt% to 90 wt% of hexane, 0 wt% to 90 wt% of hexene, 0 wt% to 50 wt% of methanol, 0 wt% to 50 wt% of ethanol, and 0 wt% to 50 wt% of water, and a total content of methanol, ethanol, and water may be greater than or equal to 10 wt%.

[0014] A reaction temperature of the coke control reaction may be 300°C to 700°C.

[0015] The present application also provides a method for preparing light olefins from an oxygen-containing compound that includes the method for on-line modification of a DMTO catalyst through a coke control reaction described above, and a device used thereby. The device includes a fluidized bed reactor 1 and a fluidized bed regenerator 2.

[0016] The fluidized bed reactor 1 is divided into a reaction zone, a coke control zone, and a gas-solid separation zone from bottom to top; the fluidized bed reactor 1 includes a fluidized bed reactor main shell 1-1, a reaction zone distributor 1-2, a fluidized bed reactor cooler 1-3, a coke control zone distributor 1-4, a baffle 1-5, a first gas-solid separation unit 1-6, a coke controlled catalyst delivery pipe 1-7, a coke control zone gas delivery pipe 1-8, a second gas-solid separation unit 1-9, a first gas collection chamber 1-10, a product gas delivery pipe 1-11, a first stripper 1-12, a spent catalyst slide valve 1-13, and a spent catalyst delivery pipe 1-14; and the spent catalyst slide valve 1-13 is configured to control a circulation volume of a spent catalyst.

[0017] The reaction zone distributor 1-2 is located at a bottom of the reaction zone of the fluidized bed reactor 1, and the fluidized bed reactor cooler 1-3 is located in the reaction zone.

[0018] The coke control zone is located in an annular zone above the reaction zone, n baffles 1-5 are arranged in the coke control zone, and the baffles 1-5 divide the coke control zone into n coke control zone subzones, where n is an integer and 2 ≤ n ≤ 10; a bottom of each of the coke control zone subzones is independently provided with a coke control zone distributor 1-4; a cross section of the coke control zone is annular, and a cross section of each of the coke control zone subzones is sector-annular; the 1 st< to n th< coke control zone subzones are concentrically arranged in sequence; and a catalyst circulation hole is formed in the baffles 1-5, but no catalyst circulation hole is formed in a baffle shared by the 1 st< coke control zone subzone and the n th< coke control zone subzone.

[0019] The first gas-solid separation unit 1-6 is located in the gas-solid separation zone of the fluidized bed reactor 1; an inlet of the first gas-solid separation unit 1-6 is connected to an outlet of the regenerated catalyst delivery pipe 2-9, a gas outlet of the first gas-solid separation unit 1-6 is formed in the gas-solid separation zone, and a catalyst outlet of the first gas-solid separation unit 1-6 is formed in the 1 st< coke control zone subzone; and an inlet of the coke controlled catalyst delivery pipe 1-7 is connected to the n th< coke control zone subzone, and an outlet of the coke controlled catalyst delivery pipe 1-7 is formed in the reaction zone.

[0020] A top of each of the coke control zone subzones is independently provided with a coke control zone gas delivery pipe 1-8, and an outlet of the coke control zone gas delivery pipe 1-8 is formed in the gas-solid separation zone; the second gas-solid separation unit 1-9 and the first gas collection chamber 1-10 are located in the gas-solid separation zone of the fluidized bed reactor 1; an inlet of the second gas-solid separation unit 1-9 is formed in the gas-solid separation zone of the fluidized bed reactor 1, a gas outlet of the second gas-solid separation unit 1-9 is connected to the first gas collection chamber 1-10, and a catalyst outlet of the second gas-solid separation unit 1-9 is formed in the reaction zone; the product gas delivery pipe 1-11 is connected to a top of the first gas collection chamber 1-10; the first stripper 1-12 is located below the fluidized bed reactor 1, an inlet pipe of the first stripper 1-12 penetrates through a lower fluidized bed reactor shell through the bottom of the fluidized bed reactor 1 and is opened above the reaction zone distributor 1-2; and an inlet of the spent catalyst slide valve 1-13 is connected to an outlet pipe at a bottom of the first stripper 1-12, an outlet of the spent catalyst slide valve 1-13 is connected to an inlet of the spent catalyst delivery pipe 1-14 through a pipeline, and an outlet of the spent catalyst delivery pipe 1-14 is connected to a middle part of the fluidized bed regenerator 2.

[0021] In a preferred embodiment, the first gas-solid separation unit 1-6 may be a gas-solid cyclone separator.

[0022] In a preferred embodiment, the first gas-solid separation unit 1-6 may be a gas-solid rapid separator.

[0023] In a preferred embodiment, the second gas-solid separation unit 1-9 may adopt one or more sets of gas-solid cyclone separators, and each set of gas-solid cyclone separators may include a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.

[0024] A device for preparing light olefins from an oxygen-containing compound is provided, where the device includes a fluidized bed regenerator 2 for regenerating a catalyst; the fluidized bed regenerator 2 includes a regenerator shell 2-1, a regeneration zone distributor 2-2, a third gas-solid separation unit 2-3, a second gas collection chamber 2-4, a flue gas delivery pipe 2-5, a second stripper 2-6, a regenerator cooler 2-7, a regenerated catalyst slide valve 2-8, and a regenerated catalyst delivery pipe 2-9; the regeneration zone distributor 2-2 is located at a bottom of the fluidized bed regenerator 2, and the third gas-solid separation unit 2-3 is located at an upper part of the fluidized bed regenerator 2; an inlet of the third gas-solid separation unit 2-3 is formed in an upper part of the fluidized bed regenerator 2, a gas outlet of the third gas-solid separation unit 2-3 is connected to the second gas collection chamber 2-4, and a catalyst outlet of the third gas-solid separation unit 2-3 is formed in a lower part of the fluidized bed regenerator 2; the second gas collection chamber 2-4 is located at a top of the fluidized bed regenerator 2, and the flue gas delivery pipe 2-5 is connected to a top of the second gas collection chamber 2-4; the second stripper 2-6 is located outside the regenerator shell 2-1, and an inlet pipe of the second stripper 2-6 penetrates through the regenerator shell 2-1 and is opened above the regeneration zone distributor 2-2; the regenerator cooler 2-7 is located in the second stripper 2-6; and an inlet of the regenerated catalyst slide valve 2-8 is connected to a bottom of the second stripper 2-6 through a pipeline, an outlet of the regenerated catalyst slide valve 2-8 is connected to an inlet of the regenerated catalyst delivery pipe 2-9 through a pipeline, and an outlet of the regenerated catalyst delivery pipe 2-9 is connected to an inlet of the first gas-solid separation unit 1-6. The regenerated catalyst slide valve 2-8 is configured to control a circulation volume of a regenerated catalyst.

[0025] In a preferred embodiment, the third gas-solid separation unit 2-3 may adopt one or more sets of gas-solid cyclone separators, and each set of gas-solid cyclone separators may include a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.

[0026] In the method of the present application, the product gas may be composed of 38 wt% to 57 wt% of ethylene, 37 wt% to 55 wt% of propylene, less than or equal to 5 wt% of C 4 -C 6 hydrocarbon compounds, and less than or equal to 3 wt% of other components; and the other components may be methane, ethane, propane, hydrogen, CO, CO 2 , and the like, and the total selectivity of ethylene and propylene in the product gas may be 93 wt% to 96 wt%.

[0027] In the present application, when the production unit consumption is expressed, a mass of DME in the oxygen-containing compound is equivalently converted into a mass of methanol based on a mass of the element C, and a unit of the production unit consumption is ton of methanol / ton of light olefins.

[0028] In the method of the present application, the production unit consumption may be 2.50 to 2.58 tons of methanol / ton of light olefins.Example 1

[0029] The device shown in FIG. 1 and FIG. 2 is adopted in this example, where 2 baffles are arranged in the coke control zone in the fluidized bed reactor, that is, n = 2; the coke control zone includes 2 coke control zone subzones; and the first gas-solid separation unit is a gas-solid cyclone separator.

[0030] Specifically, as shown in FIG. 1, a diameter of a junction between the lower shell and the upper shell gradually increases from bottom to top, such that a diameter of the gas-solid separation zone is larger than a diameter of the reaction zone. The coke control zone is located at the junction of the lower shell and the upper shell. A longitudinal cross section of each of the baffles is in a parallelogram.

[0031] In this example, the coke control raw material is a mixture of 6 wt% of butane, 81 wt% of butene, 2 wt% of methanol, and 11 wt% of water; the oxygen-containing compound is methanol; the regeneration gas is air; an active component in the catalyst is an SAPO-34 molecular sieve; a coke content in the regenerated catalyst is about 1 wt%; a coke content in the coke controlled catalyst is about 4 wt%, where a total mass of polymethylbenzene and polymethylnaphthalene accounts for about 85 wt% of a total mass of coke, a mass of coke species with a molecular weight greater than 184 accounts for about 6 wt% of the total mass of coke, and a quartile deviation of a coke content distribution in the coke controlled catalyst is about 0.9 wt%; and a coke content in the spent catalyst is about 9 wt%.

[0032] Process operating conditions of the coke control zone of the fluidized bed reactor are as follows: apparent gas linear velocity: about 0.3 m / s, reaction temperature: about 500°C, reaction pressure: about 100 kPa, and bed density: about 600 kg / m 3< .

[0033] Process operating conditions of the reaction zone of the fluidized bed reactor are as follows: apparent gas linear velocity: about 2.0 m / s, reaction temperature: about 550°C, reaction pressure: about 100 kPa, and bed density: about 150 kg / m 3< .

[0034] Process operating conditions of the fluidized bed regenerator are as follows: apparent gas linear velocity: about 0.5 m / s; regeneration temperature: about 700°C; regeneration pressure: about 100 kPa; and bed density: about 700 kg / m 3< .

[0035] In this example, the product gas is composed of 57 wt% of ethylene, 37 wt% of propylene, 3 wt% of C 4 -C 6 hydrocarbon compounds, and 3 wt% of other components, where the other components include methane, ethane, propane, hydrogen, CO, CO 2 , and the like; and the production unit consumption is 2.55 tons of methanol / ton of light olefins.Example 2

[0036] The device shown in FIG. 1 and FIG. 2 is adopted in this example, where 10 baffles are arranged in the coke control zone in the fluidized bed reactor, that is, n = 10; the coke control zone includes 10 coke control zone subzones; and the first gas-solid separation unit is a gas-solid cyclone separator.

[0037] In this example, the coke control raw material is a mixture of 22 wt% of methane, 24 wt% of ethane, 3 wt% of ethylene, 28 wt% of propane, 4 wt% of propylene, 7 wt% of hydrogen, and 12 wt% of water; the oxygen-containing compound is a mixture of 82 wt% of methanol and 18 wt% of DME; the regeneration gas is a mixture of 50 wt% of air and 50 wt% of water vapor; an active component in the catalyst is an SAPO-34 molecular sieve; a coke content in the regenerated catalyst is about 3 wt%; a coke content in the coke controlled catalyst is about 9 wt%, where a total mass of polymethylbenzene and polymethylnaphthalene accounts for about 78 wt% of a total mass of coke, a mass of coke species with a molecular weight greater than 184 accounts for about 13 wt% of the total mass of coke, and a quartile deviation of a coke content distribution in the coke controlled catalyst is about 0.2 wt%; and a coke content in the spent catalyst is about 13 wt%.

[0038] Process operating conditions of the coke control zone of the fluidized bed reactor are as follows: apparent gas linear velocity: about 0.1 m / s, reaction temperature: about 300°C, reaction pressure: about 500 kPa, and bed density: about 800 kg / m 3< .

[0039] Process operating conditions of the reaction zone of the fluidized bed reactor are as follows: apparent gas linear velocity: about 0.5 m / s, reaction temperature: about 350°C, reaction pressure: about 500 kPa, and bed density: about 500 kg / m 3< .

[0040] Process operating conditions of the fluidized bed regenerator are as follows: apparent gas linear velocity: about 2.0 m / s; regeneration temperature: about 600°C; regeneration pressure: about 500 kPa; and bed density: about 150 kg / m 3< .

[0041] In this example, the product gas is composed of 38 wt% of ethylene, 55 wt% of propylene, 5 wt% of C 4 -C 6 hydrocarbon compounds, and 2 wt% of other components, where the other components include methane, ethane, propane, hydrogen, CO, CO 2 , and the like; and the production unit consumption is 2.58 tons of methanol / ton of light olefins.Example 3

[0042] The device shown in FIG. 1 and FIG. 2 is adopted in this example, where 4 baffles are arranged in the coke control zone in the fluidized bed reactor, that is, n = 4; the coke control zone includes 4 coke control zone subzones; and the first gas-solid separation unit is a gas-solid rapid separator.

[0043] In this example, the coke control raw material is a mixture of 1 wt% of propane, 1 wt% of propylene, 3 wt% of butane, 51 wt% of butene, 3 wt% of pentane, 22 wt% of pentene, 1 wt% of hexane, 7 wt% of hexene, 2 wt% of methanol, and 9 wt% of water; the oxygen-containing compound is DME; the regeneration gas is a mixture of 50 wt% of air and 50 wt% of oxygen; an active component in the catalyst is an SAPO-34 molecular sieve; a coke content in the regenerated catalyst is about 2 wt%; a coke content in the coke controlled catalyst is about 6 wt%, where a total mass of polymethylbenzene and polymethylnaphthalene accounts for about 81 wt% of a total mass of coke, a mass of coke species with a molecular weight greater than 184 accounts for about 15 wt% of the total mass of coke, and a quartile deviation of a coke content distribution in the coke controlled catalyst is about 0.6 wt%; and a coke content in the spent catalyst is about 11 wt%.

[0044] Process operating conditions of the coke control zone of the fluidized bed reactor are as follows: apparent gas linear velocity: about 0.4 m / s, reaction temperature: about 700°C, reaction pressure: about 300 kPa, and bed density: about 500 kg / m 3< .

[0045] Process operating conditions of the reaction zone of the fluidized bed reactor are as follows: apparent gas linear velocity: about 1.0 m / s, reaction temperature: about 450°C, reaction pressure: about 300 kPa, and bed density: about 300 kg / m 3< .

[0046] Process operating conditions of the fluidized bed regenerator are as follows: apparent gas linear velocity: about 1.0 m / s; regeneration temperature: about 750°C; regeneration pressure: about 300 kPa; and bed density: about 360 kg / m 3< .

[0047] In this example, the product gas is composed of 48 wt% of ethylene, 47 wt% of propylene, 3 wt% of C 4 -C 6 hydrocarbon compounds, and 2 wt% of other components, where the other components include methane, ethane, propane, hydrogen, CO, CO 2 , and the like; and the production unit consumption is 2.53 tons of methanol / ton of light olefins.Example 4

[0048] The device shown in FIG. 1 and FIG. 2 is adopted in this example, where 6 baffles are arranged in the coke control zone in the fluidized bed reactor, that is, n = 6; the coke control zone includes 6 coke control zone subzones; and the first gas-solid separation unit is a gas-solid rapid separator.

[0049] In this example, the coke control raw material is a mixture of 5 wt% of butane, 72 wt% of butene, 8 wt% of methanol, and 15 wt% of water; the oxygen-containing compound is methanol; the regeneration gas is a mixture of 50 wt% of air and 50 wt% of nitrogen; an active component in the catalyst is an SAPO-34 molecular sieve; a coke content in the regenerated catalyst is about 2 wt%; a coke content in the coke controlled catalyst is about 6 wt%, where a total mass of polymethylbenzene and polymethylnaphthalene accounts for about 70 wt% of a total mass of coke, a mass of coke species with a molecular weight greater than 184 accounts for about 24 wt% of the total mass of coke, and a quartile deviation of a coke content distribution in the coke controlled catalyst is about 0.3 wt%; and a coke content in the spent catalyst is about 12 wt%.

[0050] Process operating conditions of the coke control zone of the fluidized bed reactor are as follows: apparent gas linear velocity: about 0.5 m / s, reaction temperature: about 600°C, reaction pressure: about 200 kPa, and bed density: about 400 kg / m 3< .

[0051] Process operating conditions of the reaction zone of the fluidized bed reactor are as follows: apparent gas linear velocity: about 1.5 m / s, reaction temperature: about 500°C, reaction pressure: about 200 kPa, and bed density: about 200 kg / m 3< .

[0052] Process operating conditions of the fluidized bed regenerator are as follows: apparent gas linear velocity: about 1.5 m / s; regeneration temperature: about 680°C; regeneration pressure: about 200 kPa; and bed density: about 280 kg / m 3< .

[0053] In this example, the product gas is composed of 53 wt% of ethylene, 43 wt% of propylene, 3 wt% of C 4 -C 6 hydrocarbon compounds, and 1 wt% of other components, where the other components include methane, ethane, propane, hydrogen, CO, CO 2 , and the like; and the production unit consumption is 2.50 tons of methanol / ton of light olefins.Comparative Example

[0054] This comparative example is different from Example 4 in that, the coke control reaction is not used for on-line modification of the DMTO catalyst; and the raw material fed into the coke control zone is nitrogen, which is an inert gas and does not change the properties of the regenerated catalyst in the coke control zone, that is, a catalyst entering the reaction zone is the regenerated catalyst.

[0055] In this example, the product gas is composed of 43 wt% of ethylene, 39 wt% of propylene, 12 wt% of C 4 -C 6 hydrocarbon compounds, and 6 wt% of other components, where the other components include methane, ethane, propane, hydrogen, CO, CO 2 , and the like; and the production unit consumption is 2.91 tons of methanol / ton of light olefins.

[0056] This comparative example shows that the on-line modification of a DMTO catalyst through a coke control reaction can greatly improve the performance of the catalyst and reduce the production unit consumption.

Claims

1. A fluidized bed reactor (1), wherein the fluidized bed reactor comprises a main shell (1-1); the main shell comprises an upper shell, a lower shell, and a junction connected between the upper shell and the lower shell, a diameter of the junction gradually increases from a lower end of the junction that is connected with the lower shell to an upper end of the junction that is connected with the upper shell; the upper shell encloses a gas-solid separation zone that ends at the upper end of the junction, and the lower shell encloses a reaction zone that ends at the lower end of the junction, such that a diameter of the gas-solid separation zone is larger than a diameter of the reaction zone; the reaction zone axially communicates with the gas-solid separation zone; characterized in that the fluidized bed reactor further comprises a coke control zone shell, the coke control zone shell is circumferentially arranged on an outer wall of the junction and a part of the lower shell to enclose an annular cavity, and the annular cavity is a coke control zone; n baffles (1-5) are radially arranged in the coke control zone, and the n baffles divide the coke control zone into n coke control zone subzones, where n is an integer; the coke control zone subzones are provided with a coke control raw material inlet; and a catalyst circulation hole is formed in each of n-1 of the baffles, such that a catalyst and a coke control raw material entering the coke control zone flow in an annular direction.

2. The fluidized bed reactor according to claim 1, wherein in the coke control zone, the n baffles comprise a 1st baffle, and a 2nd baffle to an nth baffle; no catalyst circulation hole is formed in the 1st baffle; the catalyst circulation hole is formed in each of the 2nd baffle to the nth baffle; a coke control zone catalyst inlet is formed in a 1st coke control zone subzone formed through division by the 1st baffle and the 2nd baffle; a coke controlled catalyst delivery pipe (1-7) is arranged in an nth coke control zone subzone formed through division by the 1st baffle and the nth baffle, and an outlet of the coke controlled catalyst delivery pipe is formed in the reaction zone; the coke control raw material inlet is formed at bottoms of the coke control zone subzones, and the coke control raw material inlet is a coke control zone distributor (1-4); and a coke control zone gas delivery pipe (1-8) is arranged at tops of the coke control zone subzones, and an outlet of the coke control zone gas delivery pipe is formed in the gas-solid separation zone.

3. The fluidized bed reactor according to claim 1, wherein n has a value range of 2 ≤ n ≤ 10.

4. The fluidized bed reactor according to claim 1, wherein a reaction zone distributor (1-2) is further arranged at a bottom of the reaction zone; and the reaction zone distributor is configured to feed a reaction raw material.

5. The fluidized bed reactor according to claim 4, wherein the reaction zone is provided with a fluidized bed reactor cooler (1-3), and the bottom of the reaction zone is provided with a first stripper (1-12); an inlet of the first stripper is formed inside the lower shell; an outlet of the first stripper is formed outside the lower shell; an open end of the inlet of the first stripper is located above an outlet end of the coke controlled catalyst delivery pipe; and the outlet end of the coke controlled catalyst delivery pipe is located above the reaction zone distributor.

6. The fluidized bed reactor according to claim 1, wherein the gas-solid separation zone is provided with a first gas-solid separation unit (1-6) and a second gas-solid separation unit (1-9); a catalyst outlet pipe of the first gas-solid separation unit penetrates through a top of the coke control zone and is inserted in the 1st coke control zone subzone; a gas outlet of the first gas-solid separation unit is formed in the gas-solid separation zone; an inlet of the second gas-solid separation unit is formed in the gas-solid separation zone; a catalyst outlet end of the second gas-solid separation unit is located in the reaction zone; preferably, a first gas collection chamber (1-10) is further arranged in an upper part of the gas-solid separation zone; a gas outlet of the second gas-solid separation unit communicates with the first gas collection chamber; and the first gas collection chamber further communicates with a product gas delivery pipe (1-11).

7. A device for preparing light olefins from an oxygen-containing compound, wherein the device comprises a fluidized bed regenerator (2) and the fluidized bed reactor according to claim 1.

8. The device according to claim 7, wherein the fluidized bed regenerator comprises a regenerator shell (2-1); the regenerator shell comprises an upper regenerator shell and a lower regenerator shell; the upper regenerator shell encloses a gas-solid separation zone, and the lower regenerator shell encloses a regeneration zone; a spent catalyst inlet is formed in the regenerator shell; and the spent catalyst inlet communicates with a first stripper outlet pipe through a spent catalyst delivery pipe (1-14).

9. The device according to claim 7, wherein a regeneration zone distributor (2-2) is further arranged at a bottom of the regeneration zone; the regeneration zone distributor is configured to feed a regeneration gas; preferably, a second stripper (2-6) is arranged at the bottom of the regeneration zone; an inlet of the second stripper is formed inside the regenerator shell; an outlet of the second stripper is formed outside the regenerator shell; the second stripper communicates with a first gas-solid separation unit through a regenerated catalyst delivery pipe (2-9); and an open end of the inlet of the second stripper is located above the regeneration zone distributor.

10. The device according to claim 7, wherein a third gas-solid separation unit (2-3) and a second gas collection chamber (2-4) are further arranged in the regenerator shell; the second gas collection chamber is located at an inner top of the regenerator shell; a gas outlet of the third gas-solid separation unit communicates with the second gas collection chamber; the second gas collection chamber communicates with a flue gas delivery pipe (2-5); and a catalyst outlet end of the third gas-solid separation unit is located above an open end of a second stripper inlet pipe.

11. A method for preparing light olefins, wherein the method for preparing light olefins comprises preparing light olefins using the device according to claim 7; the method for preparing light olefins comprises preparing light olefins from an oxygen-containing compound, wherein an on-line modification of a dimethyl ether / methanol to olefins (DMTO) catalyst through a coke control reaction is performed using the fluidized bed reactor; wherein the method comprises the following step: feeding a catalyst and a coke control raw material into the coke control zone, wherein the catalyst reacts with the coke control raw material while flowing in an annular direction along the coke control zone subzones to generate a product comprising a coke controlled catalyst, and the coke controlled catalyst is a modified DMTO catalyst; and the method for preparing light olefins further comprises the following steps: allowing a spent catalyst in the reaction zone of the fluidized bed reactor to enter the fluidized bed regenerator and undergo a regeneration treatment to generate a regenerated catalyst, and allowing the regenerated catalyst to enter the coke control zone of the fluidized bed reactor and to contact and react with the coke control raw material.

12. The method according to claim 11, wherein the method for preparing light olefins comprises: allowing the spent catalyst in the reaction zone to enter the fluidized bed regenerator through the first stripper and the spent catalyst delivery pipe, and to contact and react with the regeneration gas to obtain a stream E with a flue gas and a regenerated catalyst; allowing the stream E to enter the third gas-solid separation unit to separate the flue gas and the regenerated catalyst; and allowing the separated regenerated catalyst to enter the coke control zone of the fluidized bed reactor through the second stripper, the regenerated catalyst delivery pipe, and the first gas-solid separation unit, and to contact and react with the coke control raw material.

13. The method according to claim 11, wherein a coke content in the regenerated catalyst is less than or equal to 3 wt%.

14. The method according to claim 12, wherein the regeneration gas comprises 0 wt% to 100 wt% of air, 0 wt% to 50 wt% of oxygen, 0 wt% to 50 wt% of nitrogen, and 0 wt% to 50 wt% of water vapor; and contents of the air, the oxygen, the nitrogen, and the water vapor are not simultaneously zero.

15. The method according to claim 11, wherein process conditions of the regeneration zone are as follows: apparent gas linear velocity: 0.5 m / s to 2.0 m / s; regeneration temperature: 600°C to 750°C; regeneration pressure: 100 kPa to 500 kPa; and bed density: 150 kg / m3 to 700 kg / m3.