COKE CONTROL REACTOR, AND DEVICE AND METHOD FOR PREPARING LOW-CARBON OLEFINS FROM OXYGEN-CONTAINING COMPOUND

Abstract

A coke control reactor, and a device and method for preparing low-carbon olefins from an oxygen-containing compound are provided. The coke control reactor includes a coke control reactor shell, a reaction zone I, and a coke controlled catalyst settling zone; a cross-sectional area at any position of the reaction zone I is less than that of the coke controlled catalyst settling zone; n baffles are arranged in a vertical direction in the reaction zone I; the n baffles divide the reaction zone I into m reaction zone I subzones; and a catalyst circulation hole is formed in each of the baffles, such that a catalyst flows in the reaction zone I in a preset manner. A catalyst charge in the present coke control reactor can be automatically adjusted, and an average residence time of a catalyst in the coke control reactor can be controlled by changing process operating conditions.

Claims

1. A coke control reactor, wherein the coke control reactor comprises a coke control reactor shell, a first reaction zone, and a coke controlled catalyst settling zone; the coke control reactor shell comprises an upper coke control reactor shell and a lower coke control reactor shell; the upper coke control reactor shell encloses the coke controlled catalyst settling zone; the lower coke control reactor shell encloses the first reaction zone; the first reaction zone communicates with the coke controlled catalyst settling zone; a cross-sectional area at any position of the first reaction zone is less than a cross-sectional area at any position of the coke controlled catalyst settling zone; n baffles are arranged in a vertical direction in the first reaction zone, bottoms of the n baffles are connected to a bottom of the coke control reactor, tops of the n baffles are located in the coke controlled catalyst settling zone, and the n baffles divide the first reaction zone into m subzones of the first reaction zone, wherein m and n are both integers; and a catalyst circulation hole is formed in each of the n baffles, such that a catalyst flows in the first reaction zone in a preset manner.

2. The coke control reactor according to claim 1, wherein 1≤n≤9; and 2≤m≤10; wherein a cross section of the first reaction zone and a cross section of each of the m subzones are all rectangular; the catalyst circulation hole is formed in each of the n baffles; and the catalyst circulation holes on two adjacent baffles are staggered up and down, such that the catalyst flows in the first reaction zone in a polyline manner; wherein the cross section of the first reaction zone is circular; the cross section of each of the m subzones is fan-shaped; and at least one catalyst circulation hole is formed in each of n−1 of the n baffles, such that the catalyst flows in the first reaction zone in an annular manner; or wherein the cross section of the first reaction zone is annular; the cross section of each of the m subzones is fan-shaped; and at least one catalyst circulation hole is formed in each of n−1 of the n baffles, such that the catalyst flows in the first reaction zone in the annular manner.

3-5. (canceled)

6. The coke control reactor according to claim 1, wherein a cross-sectional area of the coke controlled catalyst settling zone is 1.5 to 3 times a cross-sectional area of the first reaction zone; wherein the coke control reactor is a bubbling fluidized bed reactor.

7. The coke control reactor according to claim 1, wherein the coke control reactor further comprises a transition zone; the transition zone is located between the first reaction zone and the coke controlled catalyst settling zone; a cross-sectional area at any position of the transition zone is between the cross-sectional area at any position of the first reaction zone and the cross-sectional area at any position of the coke controlled catalyst settling zone; and the transition zone, the first reaction zone, and the coke controlled catalyst settling zone communicate with each other coaxially.

8. (canceled)

9. The coke control reactor according to claim 1, wherein the first reaction zone comprises a catalyst inlet, a coke controlled catalyst outlet, and a coke control raw material inlet; the m subzones of the first reaction zone comprise a 1.sup.st subzone, and a 2.sup.nd subzone to an m.sup.th subzone; the catalyst inlet is formed in the 1.sup.st subzone; the coke controlled catalyst outlet is formed in the m.sup.th subzone; the coke control raw material inlet is formed at a bottom of each of m subzones; the coke controlled catalyst settling zone comprises a coke control gas outlet; and the coke control gas outlet is formed at a top of the coke controlled catalyst settling zone; wherein a coke control reactor distributor is provided at the coke control raw material inlet.

10-20. (canceled)

21. A device for preparing low-carbon olefins from an oxygen-containing compound, wherein the device comprises a methanol conversion reactor and the coke control reactor according to claim 1.

22. The device according to claim 21, wherein the methanol conversion reactor comprises a methanol conversion reactor shell and a delivery pipe; the methanol conversion reactor shell comprises a lower methanol conversion reactor shell and an upper methanol conversion reactor shell; the lower methanol conversion reactor shell encloses a second reaction zone; the delivery pipe is located above the second reaction zone; the delivery pipe has a first end closed and a second end communicating with the second reaction zone; the upper methanol conversion reactor shell is arranged on a periphery of the delivery pipe; the upper methanol conversion reactor shell and a pipe wall of the delivery pipe enclose a cavity; the cavity is divided into a spent catalyst zone and a gas-solid separation zone from bottom to top, respectively; and the spent catalyst zone is provided with a spent catalyst zone gas distributor; wherein the gas-solid separation zone is provided with a first gas-solid separation unit of the methanol conversion reactor; an upper part of the delivery pipe is connected to an inlet of the first gas-solid separation unit of the methanol conversion reactor; a spent catalyst outlet of the first gas-solid separation unit of the methanol conversion reactor is formed in the spent catalyst zone; a gas outlet of the first gas-solid separation unit of the methanol conversion reactor communicates with a methanol conversion reactor gas collection chamber; and the methanol conversion reactor gas collection chamber communicates with a product gas delivery pipe; wherein the gas-solid separation zone is further provided with a second gas-solid separation unit of the methanol conversion reactor; a gas inlet of the second gas-solid separation unit of the methanol conversion reactor is formed in the gas-solid separation zone; a spent catalyst outlet of the second gas-solid separation unit of the methanol conversion reactor is formed in the spent catalyst zone; and a gas outlet of the second gas-solid separation unit of the methanol conversion reactor communicates with the methanol conversion reactor gas collection chamber.

23-24. (canceled)

25. The device according to claim 22, wherein the spent catalyst zone gas distributor is located below the first gas-solid separation unit of the methanol conversion reactor and the second gas-solid separation unit of the methanol conversion reactor.

26. The device according to claim 22, wherein a spent catalyst circulation pipe and a spent catalyst inclined pipe are further arranged outside the spent catalyst zone; the spent catalyst circulation pipe is configured to connect the spent catalyst zone and the second reaction zone; and the spent catalyst inclined pipe is configured to output a spent catalyst.

27. The device according to claim 22, wherein the second reaction zone communicates with the first reaction zone through a coke controlled catalyst delivery pipe.

28. The device according to claim 26, wherein the device further comprises a regenerator; the regenerator is connected to the spent catalyst inclined pipe, such that the spent catalyst is able to be delivered to the regenerator; the regenerator is connected to a regenerated catalyst delivery pipe, such that a regenerated catalyst is able to be delivered to the coke control reactor; and an inner bottom of the regenerator is provided with a regenerator distributor; wherein a bottom of the regenerator is further provided with a regenerator stripper; an upper section of the regenerator stripper is arranged inside the regenerator, and an inlet of the upper section of the regenerator stripper is formed above the regenerator distributor; and a lower section of the regenerator stripper is arranged outside the regenerator, and an outlet of the lower section of the regenerator stripper is connected to the regenerated catalyst delivery pipe; wherein the regenerator is connected to the spent catalyst inclined pipe through a spent catalyst delivery pipe and a methanol conversion reactor stripper; and the regenerator is connected to the regenerated catalyst delivery pipe through the regenerator stripper; wherein the regenerator is further provided with a regenerator gas-solid separation unit and a regenerator gas collection chamber; a regenerated catalyst outlet of the regenerator gas-solid separation unit is formed above the regenerator distributor; a gas outlet of the regenerator gas-solid separation unit is connected to the regenerator gas collection chamber; and the regenerator gas collection chamber is connected to a flue gas delivery pipe located outside the regenerator.

29-31. (canceled)

32. A method for preparing low-carbon olefins from an oxygen-containing compound, comprising a method for on-line modification of a dimethyl ether/methanol to olefins (DMTO) catalyst using the coke regulation reactor according to claim 1.

33. The method according to claim 32, wherein the method further comprises: feeding a coke control product gas into a gas-solid separation zone of a methanol conversion reactor; and feeding a coke controlled catalyst into a second reaction zone of the methanol conversion reactor; wherein in the second reaction zone, a raw material with the oxygen-containing compound contacts and reacts with the coke controlled catalyst to generate a first stream with low-carbon olefins and a spent catalyst wherein the first stream is separated into a first gas-phase stream and a first solid-phase stream after being subjected to gas-solid separation in the gas-solid separation zone of the methanol conversion reactor; the first gas-phase stream enters a methanol conversion reactor gas collection chamber; the first solid-phase stream enters a spent catalyst zone; and the first gas-phase stream comprises the low-carbon olefins, and the first solid-phase stream comprises the spent catalyst wherein a spent catalyst zone fluidizing gas is fed into the spent catalyst zone; the spent catalyst zone fluidizing gas and the coke control product gas are mixed and carry a part of the spent catalyst to produce a second stream; the second stream is separated into a second gas-phase stream and a second solid-phase stream after being subjected to gas-solid separation; the second gas-phase stream enters the methanol conversion reactor gas collection chamber; the second solid-phase stream enters the spent catalyst zone; the second gas-phase stream is a mixed gas of the spent catalyst zone fluidizing gas and the coke control product gas; and the second solid-phase stream is the spent catalyst wherein the first gas-phase stream and the second gas-phase stream are mixed in the methanol conversion reactor gas collection chamber to produce a product gas, and the product gas enters a downstream working section through a product gas delivery pipe; wherein a part of the spent catalyst in the spent catalyst zone is returned to a bottom of the second reaction zone through a spent catalyst circulation pipe; and a remaining part of the spent catalyst is discharged through a spent catalyst inclined pipe; wherein the remaining part of the spent catalyst discharged through the spent catalyst inclined pipe is fed into a regenerator; and a regeneration gas is fed into the regenerator to contact and react with the spent catalyst to obtain a third stream with a flue gas and a regenerated catalyst wherein the third stream is subjected to gas-solid separation; a separated flue gas enters a regenerator gas collection chamber, and then enters a downstream flue gas treatment system through a flue gas delivery pipe; and a separated regenerated catalyst is stripped and cooled, and then enters a coke control reactor.

34-40. (Canceled)

41. The method according to claim 33, wherein the oxygen-containing compound comprises methanol and/or dimethyl ether (DME); wherein a coke content in the spent catalyst is 9 wt % to 13 wt %.

42. (canceled)

43. The method according to claim 33, wherein the spent catalyst zone fluidizing gas comprises nitrogen and/or water vapor; 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.

44. (canceled)

45. The method according to claim 33, wherein process operating conditions of the second reaction zone of the methanol conversion reactor are as follows: apparent gas linear velocity: 0.5 m/s to 7.0 m/s; reaction temperature: 350° C. to 550° C.; reaction pressure: 100 kPa to 500 kPa; and bed density: 100 kg/m.sup.3 to 500 kg/m.sup.3; wherein process operating conditions of the spent catalyst zone of the methanol conversion reactor are as follows: apparent gas linear velocity: 0.1 m/s to 1.0 m/s; reaction temperature: 350° C. to 550° C.; reaction pressure: 100 kPa to 500 kPa; and bed density: 200 kg/m.sup.3 to 800 kg/m.sup.3.

46. (canceled)

47. The method according to claim 33, wherein process operating conditions of the regenerator 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/m.sup.3 to 700 kg/m.sup.3.

48. The method according to claim 32, wherein the method for on-line modification of the DMTO catalyst at least comprises feeding a catalyst and a coke control raw material into the first reaction zone to allow a reaction to generate a product with a coke controlled catalyst; wherein the catalyst flows in the preset manner through the catalyst circulation holes on the n baffles; wherein the coke control raw material comprises C.sub.1-C.sub.6 hydrocarbon compounds; wherein the C.sub.1-C.sub.6 hydrocarbon compounds are at least one selected from the group consisting of C.sub.1-C.sub.6 alkanes and C.sub.1-C.sub.6 olefins; wherein the coke control raw material further comprises at least one from the group consisting of hydrogen, alcohol compound, and water; and a proportion of a total mass of the alcohol compound and the water in a mass of the coke control raw material is greater than or equal to 10% and less than or equal to 50%; wherein the alcohol compound is at least one selected from the group consisting of methanol and ethanol; wherein the coke control raw material comprises 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 % to50 wt % of ethanol, and 0 wt % to 50 wt % of water; and a content of the hydrocarbon compounds is greater than 0%.

49. The method according to claim 48, wherein the catalyst comprises an SAPO-34 molecular sieve; a coke content in the catalyst is less than or equal to 3 wt %; a coke content in the coke controlled catalyst is 4 wt % to 9 wt %; a quartile deviation of a coke content distribution in the coke controlled catalyst is less than 1 wt %; coke species in the coke controlled catalyst comprise polymethylbenzene and polymethylnaphthalene; a total mass of the polymethylbenzene and the polymethylnaphthalene accounts for greater than or equal to 70 wt % of a total mass of coke; 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 the total mass of the coke refers to a total mass of the coke species.

50. The method according to claim 48, wherein process operating conditions of the first reaction zone of the coke control reactor are as follows: apparent gas linear velocity: 0.1 m/s to 0.5 m/s; reaction temperature: 300° C. to 700° C.; reaction pressure: 100 kPa to 500 kPa; and bed density: 400 kg/m.sup.3 to 800 kg/m.sup.3; wherein the method comprises: feeding a coke control raw material and the catalyst into the first reaction zone to allow a reaction to generate a coke controlled catalyst and a coke control product gas; allowing the coke controlled catalyst to pass through the m subzones of the first reaction zone in sequence through the catalyst circulation holes on the n baffles and then flow out through a coke controlled catalyst outlet; and allowing the coke control product gas to flow out through a coke control gas outlet.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0150] FIG. 1 is a schematic diagram of a DMTO device for preparing low-carbon olefins from an oxygen-containing compound according to an embodiment of the present application.

[0151] Reference numerals in FIG. 1:

[0152] 1 represents a coke control reactor; 1-1 represents a coke control reactor shell; 1-2 represents a coke control reactor distributor; 1-3 represents a baffle; 1-4 represents a coke controlled catalyst delivery pipe; 1-5 represents a coke controlled catalyst slide valve; 1-6 represents a coke control product gas delivery pipe; 2 represents a methanol conversion reactor; 2-1 represents a methanol conversion reactor shell; 2-2 represents a methanol conversion reactor distributor; 2-3 represents a delivery pipe; 2-4 represents a first gas-solid separation unit of the methanol conversion reactor; 2-5 represents a methanol conversion reactor gas collection chamber; 2-6 represents a spent catalyst zone gas distributor; 2-7 represents a methanol conversion reactor cooler; 2-8 represents a second gas-solid separation unit of the methanol conversion reactor; 2-9 represents a product gas delivery pipe; 2-10 represents a spent catalyst circulation pipe; 2-11 represents a spent catalyst circulation slide valve; 2-12 represents a spent catalyst inclined pipe; 2-13 represents a methanol conversion reactor stripper; 2-14 represents a spent catalyst slide valve; 2-15 represents a spent catalyst delivery pipe; 3 represents a regenerator; 3-1 represents a regenerator shell; 3-2 represents a regenerator distributor; 3-3 represents a regenerator gas-solid separation unit; 3-4 represents a regenerator gas collection chamber; 3-5 represents a flue gas delivery pipe; 3-6 represents a regenerator stripper; 3-7 represents a regenerator cooler; 3-8 represents a regenerated catalyst slide valve; and 3-9 represents a regenerated catalyst delivery pipe.

[0153] FIG. 2 is a schematic diagram of cross sections of a structure of the reaction zone of the coke control reactor of an embodiment of the present application, where a cross section of the reaction zone I of the coke control reactor of the embodiment is circular, and a cross section of a reaction zone subzone is fan-shaped; and the 1.sup.st to 4.sup.th reaction zone subzones are arranged concentrically in a counterclockwise direction, and a baffle shared by the 1.sup.st reaction zone subzone and the 4th reaction zone subzone of the coke control reactor does not have catalyst circulation holes.

[0154] Reference numerals in FIG. 2:

[0155] 1 represents a coke control reactor; 1-1 represents a coke control reactor shell; 1-3 represents a baffle; 1-4 represents a coke controlled catalyst delivery pipe; and 3-9 represents a regenerated catalyst delivery pipe.

[0156] FIG. 3 is a schematic diagram of cross sections of a structure of the reaction zone of the coke control reactor of an embodiment of the present application, where a cross section of the reaction zone I of the coke control reactor of the embodiment is annular, and a cross section of a reaction zone subzone is sector-annular; and the 1.sup.st to 6.sup.th reaction zone subzones are arranged concentrically in a clockwise direction, and a baffle shared by the 1.sup.st reaction zone subzone and the 6.sup.th reaction zone subzone of the coke control reactor does not have catalyst circulation holes.

[0157] Reference numerals in FIG. 3: 1 represents a coke control reactor; 1-1 represents a coke control reactor shell; 1-3 represents a baffle; 1-4 represents a coke controlled catalyst delivery pipe; and 3-9 represents a regenerated catalyst delivery pipe.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0158] The present application will be described in detail below with reference to examples, but the present application is not limited to these examples.

[0159] Unless otherwise specified, the raw materials and catalysts in the examples of the present application are all purchased from commercial sources.

[0160] The DMTO catalyst used in the examples of the present application is from Zhongke Catalysis (Dalian) Co., Ltd.

[0161] 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:

[0162] (a) a regenerated catalyst is delivered to a coke control reactor 1;

[0163] (b) a coke control raw material is delivered to a coke control reactor 1;

[0164] (c) the coke control raw material contacts and reacts with the regenerated catalyst in the coke control reactor 1, 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

[0165] (d) the coke controlled catalyst is delivered to a methanol conversion reactor 2.

[0166] A reaction temperature of the coke control reaction may be 300° C. to 700° C.

[0167] The present application also provides a method for preparing low-carbon 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 coke control reactor 1, a methanol conversion reactor 2, and a regenerator 3.

[0168] The coke control reactor 1 can realize the on-line modification of a DMTO catalyst through a coke control reaction, including: a coke control reactor shell 1-1, a coke control reactor distributor 1-2, a baffle 1-3, a coke controlled catalyst delivery pipe 1-4, a coke controlled catalyst slide valve 1-5, and a coke control product gas delivery pipe 1-6; the coke control reactor 1 is divided into a reaction zone I, a transition zone, and a coke controlled catalyst settling zone from bottom to top, respectively; n baffles 1-3 are arranged in the reaction zone I, bottoms of the baffles 1-3 are connected to a bottom of the coke controlled reactor shell 1-1, and tops of the baffles 1-3 are located in the transition zone, where n is an integer and 1≤n≤9; the baffles 1-3 divide the reaction zone I into m reaction zone I subzones, where m is an integer and 2≤m≤10; a bottom of each of the reaction zone I subzones is independently provided with a coke control reactor distributor 1-2, and m coke control reactor distributors 1-2 are arranged in the reaction zone I; an outlet of the regenerated catalyst delivery pipe 3-9 is connected to the 1st reaction zone I subzone of the coke controlled reactor 1, and an inlet of the coke controlled catalyst delivery pipe 1-4 is connected to the m.sup.th reaction zone I subzone of the coke control reactor 1; a catalyst circulation hole is formed in each of the baffles 1-3, and catalyst circulation holes on adjacent upper and lower baffles 1-3 are staggered; a coke controlled catalyst slide valve 1-5 is arranged in the coke controlled catalyst delivery pipe 1-4, and an outlet of the coke controlled catalyst delivery pipe 1-4 is connected to a lower part of the methanol conversion reactor 2; and an inlet of the coke control product gas delivery pipe 1-6 is connected to a top of the coke control reactor 1, and an outlet of the coke control product gas delivery pipe 1-6 is connected to an upper part of the methanol conversion reactor 2.

[0169] In a preferred embodiment, a cross section of the reaction zone I of the coke control reactor 1 may be rectangular, a cross section of the reaction zone I subzone may be rectangular, and the 1.sup.st to m.sup.th reaction zone I subzones may be arranged from left to right in sequence.

[0170] In a preferred embodiment, a cross section of the reaction zone I of the coke control reactor 1 may be circular, and a cross section of a reaction zone I subzone may be fan-shaped; and the 1.sup.st to m.sup.th reaction zone I subzones may be arranged concentrically in a clockwise or counterclockwise direction, and a baffle 1-3 shared by the 1.sup.st reaction zone I subzone and the m.sup.th reaction zone I subzone of the coke control reactor 1 may not have catalyst circulation holes.

[0171] In a preferred embodiment, a cross section of the reaction zone I of the coke control reactor 1 may be annular, and a cross section of a reaction zone I subzone may be sector-annular; and the 1.sup.st to m.sup.th reaction zone I subzones may be arranged concentrically in a clockwise or counterclockwise direction, and a baffle 1-3 shared by the 1.sup.st reaction zone I subzone and the m.sup.th reaction zone I subzone of the coke control reactor 1 may not have catalyst circulation holes.

[0172] The coke control reactor 1 may be a bubbling fluidized bed reactor.

[0173] The methanol conversion reactor 2 includes a methanol conversion reactor shell 2-1, a methanol conversion reactor distributor 2-2, a delivery pipe 2-3, a first gas-solid separation unit 2-4 of the methanol conversion reactor, a methanol conversion reactor gas collection chamber 2-5, a spent catalyst zone gas distributor 2-6, a methanol conversion reactor cooler 2-7, a second gas-solid separation unit 2-8 of the methanol conversion reactor, a product gas delivery pipe 2-9, a spent catalyst circulation pipe 2-10, a spent catalyst circulation slide valve 2-11, a spent catalyst inclined pipe 2-12, a methanol conversion reactor stripper 2-13, a spent catalyst slide valve 2-14, and a spent catalyst delivery pipe 2-15.

[0174] A lower part of the methanol conversion reactor 2 is a reaction zone II, a middle part thereof is a spent catalyst zone, and an upper part thereof is a gas-solid separation zone.

[0175] The methanol conversion reactor distributor 2-2 is located at a bottom of the reaction zone II of the methanol conversion reactor 2; the delivery pipe 2-3 is located in central zones of the middle and upper parts of the methanol conversion reactor 2; and a bottom end of the delivery pipe 2-3 is connected to a top end of the reaction zone II, and an upper part of the delivery pipe 2-3 is connected to an inlet of the first gas-solid separation unit 2-4 of the methanol conversion reactor.

[0176] The first gas-solid separation unit 2-4 of the methanol conversion reactor is located in the gas-solid separation zone of the methanol conversion reactor; and a gas outlet of the first gas-solid separation unit 2-4 of the methanol conversion reactor is connected to the methanol conversion reactor gas collection chamber 2-5, and a catalyst outlet of the first gas-solid separation unit 2-4 of the methanol conversion reactor is formed in the spent catalyst zone.

[0177] The spent catalyst zone gas distributor 2-6 is located at a bottom of the spent catalyst zone, and the methanol conversion reactor cooler 2-7 is located in the spent catalyst zone.

[0178] The second gas-solid separation unit 2-8 of the methanol conversion reactor is located in the gas-solid separation zone of the methanol conversion reactor; an inlet of the second gas-solid separation unit 2-8 of the methanol conversion reactor is formed in the gas-solid separation zone of the methanol conversion reactor, a gas outlet of the second gas-solid separation unit 2-8 of the methanol conversion reactor is connected to the methanol conversion reactor gas collection chamber 2-5, and a catalyst outlet of the second gas-solid separation unit 2-8 of the methanol conversion reactor is formed in the spent catalyst zone; the methanol conversion reactor gas collection chamber 2-5 is located at a top of the methanol conversion reactor 2, and the product gas delivery pipe 2-9 is connected to a top of the methanol conversion reactor gas collection chamber 2-5; an inlet of the spent catalyst circulation pipe 2-10 is connected to the spent catalyst zone, and an outlet of the spent catalyst circulation pipe 2-10 is connected to the bottom of the reaction zone II of the methanol conversion reactor; the spent catalyst circulation slide valve 2-11 is arranged in the spent catalyst circulation pipe 2-10; an outlet of the coke controlled catalyst delivery pipe 1-4 is connected to the bottom of the reaction zone II of the methanol conversion reactor 2, an inlet of the spent catalyst inclined pipe 2-12 is connected to the spent catalyst zone, and an outlet of the spent catalyst inclined pipe 2-12 is connected to an upper part of the methanol conversion reactor stripper 2-13; the methanol conversion reactor stripper 2-13 is arranged outside the methanol conversion reactor shell 2-1; and an inlet of the spent catalyst slide valve 2-14 is connected to a bottom of the methanol conversion reactor stripper 2-13 through a pipeline, an outlet of the spent catalyst slide valve 2-14 is connected to an inlet of the spent catalyst delivery pipe 2-15 through a pipeline, and an outlet of the spent catalyst delivery pipe 2-15 is connected to a middle part of the regenerator 3.

[0179] In a preferred embodiment, the first gas-solid separation unit 2-4 of the methanol conversion reactor 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.

[0180] In a preferred embodiment, the second gas-solid separation unit 2-8 of the methanol conversion reactor 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.

[0181] The methanol conversion reactor 2 may be a fluidized bed reactor.

[0182] The regenerator 3 includes a regenerator shell 3-1, a regenerator distributor 3-2, a regenerator gas-solid separation unit 3-3, a regenerator gas collection chamber 3-4, a flue gas delivery pipe 3-5, a regenerator stripper 3-6, a regenerator cooler 3-7, a regenerated catalyst slide valve 3-8, and a regenerated catalyst delivery pipe 3-9. The regenerator distributor 3-2 is located at a bottom of the regenerator 3, and the regenerator gas-solid separation unit 3-3 is located at an upper part of the regenerator 3; an inlet of the regenerator gas-solid separation unit 3-3 is formed at an upper part of the regenerator 3, a gas outlet of the regenerator gas-solid separation unit 3-3 is connected to the regenerator gas collection chamber 3-4, and a catalyst outlet of the regenerator gas-solid separation unit 3-3 is formed at a lower part of the regenerator 3; the regenerator gas collection chamber 3-4 is located at a top of the regenerator 3, and the flue gas delivery pipe 3-5 is connected to a top of the regenerator gas collection chamber 3-4; the regenerator stripper 3-6 is located outside the regenerator shell 3-1, and an inlet pipe of the regenerator stripper 3-6 penetrates through the regenerator shell 3-1 and is opened above the regenerator distributor 3-2; the regenerator cooler 3-7 is located in the regenerator stripper 3-6; and an inlet of the regenerated catalyst slide valve 3-8 is connected to a bottom of the regenerator stripper 3-6 through a pipeline, an outlet of the regenerated catalyst slide valve 3-8 is connected to an inlet of the regenerated catalyst delivery pipe 3-9 through a pipeline, and an outlet of the regenerated catalyst delivery pipe 3-9 is connected to the coke control reactor 1.

[0183] In a preferred embodiment, the regenerator gas-solid separation unit 3-3 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.

[0184] The regenerator 3 may be a fluidized bed reactor.

[0185] The present application also provides an MTO method including the method for on-line modification of a DMTO catalyst through a coke control reaction, including the following steps:

[0186] a. a coke control raw material is fed into the reaction zone I of the coke control reactor 1 from the coke control reactor distributor 1-2, and a regenerated catalyst is fed into the reaction zone I of the coke control reactor 1 from the regenerated catalyst delivery pipe 3-9, where in the reaction zone I of the coke control reactor 1, the coke control raw material contacts the regenerated catalyst to allow a chemical reaction to generate a coke controlled catalyst and a coke control product gas; the coke controlled catalyst passes through the m reaction zone I subzones in sequence through the catalyst circulation holes on the baffles 1-3, and then enters the reaction zone II of the methanol conversion reactor 2 through the coke controlled catalyst delivery pipe 1-4 and the coke controlled catalyst slide valve 1-5; and the coke control product gas enters the gas-solid separation zone of the methanol conversion reactor 2 through the coke control product gas delivery pipe 1-6;

[0187] b. a raw material with an oxygen-containing compound is fed into the reaction zone II of the methanol conversion reactor from the methanol conversion reactor distributor 2-2, and contacts the coke controlled catalyst to generate a stream A with low-carbon olefins and a spent catalyst; the stream A enters the first gas-solid separation unit 2-4 of the methanol conversion reactor through the delivery pipe 2-3 to undergo gas-solid separation to obtain a gas-phase stream B and a solid-phase stream C, where the gas-phase stream B is a gas with low-carbon olefins and the solid-phase stream C is a spent catalyst; the gas-phase stream B enters the methanol conversion reactor gas collection chamber 2-5, and the solid-phase stream C enters the spent catalyst zone; a spent catalyst zone fluidizing gas is fed into the spent catalyst zone from the spent catalyst zone gas distributor 2-6 and contacts the spent catalyst, and the spent catalyst zone fluidizing gas and the coke control product gas are mixed and carry a part of the spent catalyst to produce a stream D; the stream D enters the second gas-solid separation unit 2-8 of the methanol conversion reactor to undergo gas-solid separation to obtain a gas-phase stream E and a solid-phase stream F, where the gas-phase stream E is a mixed gas of the spent catalyst zone fluidizing gas and the coke control product gas and the solid-phase stream F is the spent catalyst; the gas-phase stream E enters the methanol conversion reactor gas collection chamber (2-5), and the solid-phase stream F enters the spent catalyst zone; the gas-phase stream B and the gas-phase stream E are mixed in the methanol conversion reactor gas collection chamber (2-5) to produce a product gas, and the product gas enters a downstream working section through the product gas delivery pipe 2-9; a part of the spent catalyst in the spent catalyst zone is returned to a bottom of the reaction zone II of the methanol conversion reactor 2 through the spent catalyst circulation pipe 2-10 and the spent catalyst circulation slide valve 2-11, and the remaining part of the spent catalyst enters the methanol conversion reactor stripper 2-13 through the spent catalyst inclined pipe 2-12 to undergo stripping, and then enters a middle part of the regenerator 3 through the spent catalyst slide valve 2-14 and the spent catalyst delivery pipe 2-15; and

[0188] c. a regeneration gas is fed from the regenerator distributor 3-2 to the bottom of the regenerator, and in the regenerator, the regeneration gas contacts the spent catalyst to allow a chemical reaction, such that a part of coke in the spent catalyst is burned and eliminated to generate a stream G with a flue gas and a regenerated catalyst; the stream G enters the regenerator gas-solid separation unit 3-3 to undergo gas-solid separation to obtain a flue gas and a regenerated catalyst; the flue gas enters the regenerator gas collection chamber 3-4, and then enters a downstream flue gas treatment system through the flue gas delivery pipe 3-5; the regenerated catalyst is returned to the bottom of the regenerator 3; and the regenerated catalyst in the regenerator 3 enters the regenerator stripper 3-6 to be stripped and cooled, and then enters the coke control reactor 1 through the regenerated catalyst slide valve 3-8 and the regenerated catalyst delivery pipe 3-9.

[0189] In the method of the present application, the product gas may be composed of 37 wt % to 60 wt % of ethylene, 33 wt % to 57 wt % of propylene, less than or equal to 5 wt % of C.sub.4-C.sub.6 hydrocarbon compounds, and less than or equal to 4 wt % of other components; and the other components may be methane, ethane, propane, hydrogen, CO, CO.sub.2, and the like, and the total selectivity of ethylene and propylene in the product gas may be 93 wt % to 96 wt %.

[0190] In the present application, when the unit consumption of production 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 unit consumption of production is ton of methanol/ton of low-carbon olefins.

[0191] In the method of the present application, the unit consumption of production may be 2.50 to 2.58 tons of methanol/ton of low-carbon olefins.

[0192] In order to well illustrate the present application and facilitate the understanding of the technical solutions of the present application, typical but non-limiting examples of the present application are as follows:

EXAMPLE 1

[0193] In this example, the device shown in FIG. 1 is adopted, where a cross section of the reaction zone I of the coke control reactor 1 is rectangular; a cross section of the reaction zone I subzone is rectangular; n=1 and m=2; and the 1.sup.st and 2.sup.nd reaction zone I subzones are arranged from left to right in sequence.

[0194] 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 spent catalyst zone fluidizing gas is nitrogen; 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 86 wt % of a total mass of coke, a mass of coke species with a molecular weight greater than 184 accounts for about 11 wt % of a total mass of coke, and a quartile deviation of coke content distribution in the coke controlled catalyst is about 0.9 wt %; a coke content in the spent catalyst is about 9 wt %; process operating conditions of the reaction zone I of the coke control reactor 1 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.sup.3; process operating conditions of the reaction zone II of the methanol conversion reactor 2 are as follows: apparent gas linear velocity: about 7.0 m/s, reaction temperature: about 550° C., reaction pressure: about 100 kPa, and bed density: about 100 kg/m.sup.3; process operating conditions of the spent catalyst zone of the methanol conversion reactor 2 are as follows: apparent gas linear velocity: about 1.0 m/s, reaction temperature: about 550° C., reaction pressure: about 100 kPa, and bed density: about 200 kg/m.sup.3; and process operating conditions of the regenerator 3 are as follows: apparent gas linear velocity: about 0.5 m/s, regeneration temperature: about 750° C., regeneration pressure: about 100 kPa, and bed density: about 700 kg/m.sup.3.

[0195] In this example, a WHSV of the oxygen-containing compound in the methanol conversion reactor is about 20 h.sup.−1; the product gas is composed of 60 wt % of ethylene, 33 wt % of propylene, 3 wt % of C.sub.4-C.sub.6 hydrocarbon compounds, and 4 wt % of other components, where the other components include methane, ethane, propane, hydrogen, CO, CO.sub.2, and the like; and the unit consumption of production is 2.58 tons of methanol/ton of low-carbon olefins.

EXAMPLE 2

[0196] In this example, the device shown in FIG. 1 is adopted, where a cross section of the reaction zone I of the coke control reactor 1 is rectangular; a cross section of the reaction zone I subzone is rectangular; n=9 and m=10; and the 1.sup.st to 10.sup.th reaction zone I subzones are arranged from left to right in sequence.

[0197] 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 spent catalyst zone fluidizing gas is water vapor; 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 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 70 wt % of a total mass of coke, a mass of coke species with a molecular weight greater than 184 accounts for about 25 wt % of a total mass of coke, and a quartile deviation of coke content distribution in the coke controlled catalyst is about 0.2 wt %; a coke content in the spent catalyst is about 13 wt %; process operating conditions of the reaction zone I of the coke control reactor 1 are as follows: apparent gas linear velocity: about 0.2 m/s, reaction temperature: about 300° C., reaction pressure: about 500 kPa, and bed density: about 700 kg/m.sup.3; process operating conditions of the reaction zone II of the methanol conversion reactor 2 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.sup.3; process operating conditions of the spent catalyst zone of the methanol conversion reactor 2 are as follows: apparent gas linear velocity: about 0.1 m/s, reaction temperature: about 350° C., reaction pressure: about 500 kPa, and bed density: about 800 kg/m.sup.3; and process operating conditions of the regenerator 3 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.sup.3.

[0198] In this example, a WHSV of the oxygen-containing compound in the methanol conversion reactor is about 5 h.sup.−1; the product gas is composed of 37 wt % of ethylene, 57 wt % of propylene, 5 wt % of C.sub.4-C.sub.6 hydrocarbon compounds, and 1 wt % of other components, where the other components include methane, ethane, propane, hydrogen, CO, CO.sub.2, and the like; and the unit consumption of production is 2.55 tons of methanol/ton of low-carbon olefins.

EXAMPLE 3

[0199] In this example, the device shown in FIG. 1 is adopted, where a structure of the coke control reactor 1 is shown in FIG. 2; a cross section of the reaction zone I of the coke control reactor of this example is circular, and a cross section of a reaction zone I subzone is fan-shaped; n=4 and m=4; and the 1.sup.st to 4.sup.th reaction zone I subzones are arranged concentrically in a counterclockwise direction, and a baffle 1-3 shared by the 1.sup.st reaction zone I subzone and the 4.sup.th reaction zone I subzone of the coke control reactor does not have catalyst circulation holes.

[0200] 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 spent catalyst zone fluidizing gas is nitrogen; 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 1 wt %; a coke content in the coke controlled catalyst is about 6 wt %, where a total mass of polymethylbenzene and polymethylnaphthalene accounts for about 80 wt % of a total mass of coke, a mass of coke species with a molecular weight greater than 184 accounts for about 14 wt % of a total mass of coke, and a quartile deviation of coke content distribution in the coke controlled catalyst is about 0.5 wt %; a coke content in the spent catalyst is about 11 wt %; process operating conditions of the reaction zone I of the coke control reactor 1 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.sup.3; process operating conditions of the reaction zone II of the methanol conversion reactor 2 are as follows: apparent gas linear velocity: about 3.0 m/s, reaction temperature: about 450° C., reaction pressure: about 300 kPa, and bed density: about 230 kg/m.sup.3; process operating conditions of the spent catalyst zone of the methanol conversion reactor 2 are as follows: apparent gas linear velocity: about 0.2 m/s, reaction temperature: about 450° C., reaction pressure: about 300 kPa, and bed density: about 600 kg/m.sup.3; and process operating conditions of the regenerator 3 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.sup.3.

[0201] In this example, a WHSV of the oxygen-containing compound in the methanol conversion reactor is about 9 h.sup.−1; the product gas is composed of 51 wt % of ethylene, 43 wt % of propylene, 2 wt % of C.sub.4-C.sub.6 hydrocarbon compounds, and 4 wt % of other components, where the other components include methane, ethane, propane, hydrogen, CO, CO.sub.2, and the like; and the unit consumption of production is 2.55 tons of methanol/ton of low-carbon olefins.

EXAMPLE 4

[0202] In this example, the device shown in FIG. 1 is adopted, where a structure of the coke control reactor 1 is shown in FIG. 2; a cross section of the reaction zone I of the coke control reactor of this example is circular, and a cross section of a reaction zone I subzone is fan-shaped; n=6 and m=6; and the 1.sup.st to 6.sup.th reaction zone I subzones are arranged concentrically in a counterclockwise direction, and a baffle 1-3 shared by the 1.sup.st reaction zone I subzone and the 6th reaction zone I subzone of the coke control reactor does not have catalyst circulation holes.

[0203] 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 spent catalyst zone fluidizing gas is water vapor; 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 82 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 a total mass of coke, and a quartile deviation of coke content distribution in the coke controlled catalyst is about 0.3 wt %; a coke content in the spent catalyst is about 12 wt %; process operating conditions of the reaction zone I of the coke control reactor 1 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.sup.3; process operating conditions of the reaction zone II of the methanol conversion reactor 2 are as follows: apparent gas linear velocity: about 4.0 m/s, reaction temperature: about 500° C., reaction pressure: about 200 kPa, and bed density: about 160 kg/m.sup.3; process operating conditions of the spent catalyst zone of the methanol conversion reactor 2 are as follows: apparent gas linear velocity: about 0.5 m/s, reaction temperature: about 500° C., reaction pressure: about 200 kPa, and bed density: about 300 kg/m.sup.3; and process operating conditions of the regenerator 3 are as follows: apparent gas linear velocity: about 1.5 m/s, regeneration temperature: about 650° C., regeneration pressure: about 200 kPa, and bed density: about 280 kg/m.sup.3.

[0204] In this example, a WHSV of the oxygen-containing compound in the methanol conversion reactor is about 13 h.sup.−1; the product gas is composed of 53 wt % of ethylene, 42 wt % of propylene, 4 wt % of C.sub.4-C.sub.6 hydrocarbon compounds, and 1 wt % of other components, where the other components include methane, ethane, propane, hydrogen, CO, CO.sub.2, and the like; and the unit consumption of production is 2.52 tons of methanol/ton of low-carbon olefins.

EXAMPLE 5

[0205] In this example, the device shown in FIG. 1 is adopted, where a structure of the coke control reactor 1 is shown in FIG. 3; a cross section of the reaction zone I of the coke control reactor of this example is annular, and a cross section of a reaction zone I subzone is sector-annular; n=6 and m=6; and the 1.sup.st to 6.sup.th reaction zone I subzones are arranged concentrically in a clockwise direction, and a baffle 1-3 shared by the 1.sup.st reaction zone I subzone and the 6.sup.th reaction zone I subzone of the coke control reactor does not have catalyst circulation holes.

[0206] In this example, the coke control raw material is a mixture of 34 wt % of pentane, 46 wt % of pentene, 3 wt % of ethanol, and 17 wt % of water; the oxygen-containing compound is methanol; the spent catalyst zone fluidizing gas is a mixture of 5 wt % of nitrogen and 95 wt % of water vapor; 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 2 wt %; a coke content in the coke controlled catalyst is about 7 wt %, where a total mass of polymethylbenzene and polymethylnaphthalene accounts for about 74 wt % of a total mass of coke, a mass of coke species with a molecular weight greater than 184 accounts for about 10 wt % of a total mass of coke, and a quartile deviation of coke content distribution in the coke controlled catalyst is about 0.3 wt %; a coke content in the spent catalyst is about 12 wt %; process operating conditions of the reaction zone I of the coke control reactor 1 are as follows: apparent gas linear velocity: about 0.4 m/s, reaction temperature: about 400° C., reaction pressure: about 300 kPa, and bed density: about 500 kg/m.sup.3; process operating conditions of the reaction zone II of the methanol conversion reactor 2 are as follows: apparent gas linear velocity: about 3.0 m/s, reaction temperature: about 400° C., reaction pressure: about 300 kPa, and bed density: about 230 kg/m.sup.3; process operating conditions of the spent catalyst zone of the methanol conversion reactor 2 are as follows: apparent gas linear velocity: about 0.3 m/s, reaction temperature: about 400° C., reaction pressure: about 300 kPa, and bed density: about 450 kg/m.sup.3; and process operating conditions of the regenerator 3 are as follows: apparent gas linear velocity: about 0.8 m/s, regeneration temperature: about 680° C., regeneration pressure: about 300 kPa, and bed density: about 500 kg/m.sup.3.

[0207] In this example, a WHSV of the oxygen-containing compound in the methanol conversion reactor is about 9 h.sup.−1; the product gas is composed of 41 wt % of ethylene, 55 wt % of propylene, 2 wt % of C.sub.4-C.sub.6 hydrocarbon compounds, and 2 wt % of other components, where the other components include methane, ethane, propane, hydrogen, CO, CO.sub.2, and the like; and the unit consumption of production is 2.50 tons of methanol/ton of low-carbon olefins.

EXAMPLE 6

[0208] In this example, the device shown in FIG. 1 is adopted, where a structure of the coke control reactor 1 is shown in FIG. 3; a cross section of the reaction zone I of the coke control reactor of this example is annular, and a cross section of a reaction zone I subzone is sector-annular; n=9 and m=9; and the 1.sup.st to 9.sup.th reaction zone I subzones are arranged concentrically in a clockwise direction, and a baffle 1-3 shared by the 1.sup.st reaction zone I subzone and the 9.sup.th reaction zone I subzone of the coke control reactor does not have catalyst circulation holes.

[0209] In this example, the coke control raw material is a mixture of 26 wt % of hexane, 23 wt % of hexene, 2 wt % of methanol, 1 wt % of ethanol, and 48 wt % of water; the oxygen-containing compound is methanol; the spent catalyst zone fluidizing gas is a mixture of 73 wt % of nitrogen and 27 wt % of water vapor; the regeneration gas is a mixture of 85 wt % of air, 12 wt % of water vapor, and 3 wt % of nitrogen; 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 8 wt %, where a total mass of polymethylbenzene and polymethylnaphthalene accounts for about 79 wt % of a total mass of coke, a mass of coke species with a molecular weight greater than 184 accounts for about 17 wt % of a total mass of coke, and a quartile deviation of coke content distribution in the coke controlled catalyst is about 0.1 wt %; a coke content in the spent catalyst is about 12 wt %; process operating conditions of the reaction zone I of the coke control reactor 1 are as follows: apparent gas linear velocity: about 0.1 m/s, reaction temperature: about 650° C., reaction pressure: about 400 kPa, and bed density: about 800 kg/m.sup.3; process operating conditions of the reaction zone II of the methanol conversion reactor 2 are as follows: apparent gas linear velocity: about 2.0 m/s, reaction temperature: about 500° C., reaction pressure: about 400 kPa, and bed density: about 350 kg/m.sup.3; process operating conditions of the spent catalyst zone of the methanol conversion reactor 2 are as follows: apparent gas linear velocity: about 0.3 m/s, reaction temperature: about 500° C., reaction pressure: about 400 kPa, and bed density: about 450 kg/m.sup.3; and process operating conditions of the regenerator 3 are as follows: apparent gas linear velocity: about 0.8 m/s, regeneration temperature: about 700° C., regeneration pressure: about 400 kPa, and bed density: about 500 kg/m.sup.3.

[0210] In this example, a WHSV of the oxygen-containing compound in the methanol conversion reactor is about 7 h.sup.−1; the product gas is composed of 50 wt % of ethylene, 43 wt % of propylene, 4 wt % of C.sub.4-C.sub.6 hydrocarbon compounds, and 3 wt % of other components, where the other components include methane, ethane, propane, hydrogen, CO, CO.sub.2, and the like; and the unit consumption of production is 2.58 tons of methanol/ton of low-carbon olefins.

COMPARATIVE EXAMPLE

[0211] This example is a comparative example and is different from Example 5 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 reactor is nitrogen, which is an inert gas and does not change the properties of the regenerated catalyst in the coke control reactor, that is, a catalyst entering the reaction zone II of the methanol conversion reactor is the regenerated catalyst.

[0212] In this example, the product gas is composed of 36 wt % of ethylene, 44 wt % of propylene, 13 wt % of C.sub.4-C.sub.6 hydrocarbon compounds, and 7 wt % of other components, where the other components include methane, ethane, propane, hydrogen, CO, CO.sub.2, and the like; and the unit consumption of production is 2.99 tons of methanol/ton of low-carbon olefins.

[0213] 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 unit consumption of production.

[0214] The above examples are merely few examples of the present application, and do not limit the present application in any form. Although the present application is disclosed as above with preferred examples, the present application is not limited thereto. Some changes or modifications made by any technical personnel familiar with the profession using the technical content disclosed above without departing from the scope of the technical solutions of the present application are equivalent to equivalent implementation cases and fall within the scope of the technical solutions.