Methanol to olefin conversion process

Abstract

The present invention relates to a method for converting methanol to olefins, which comprises: allowing a raw material containing methanol to enter a fluidized bed reactor, contacting with a catalyst, and generating an olefin product, wherein the process causes the catalyst to be at least partially deactivated to form an at least partially deactivated catalyst; allowing a catalyst to be regenerated from the at least partially deactivated catalyst to enter a regenerator for regeneration, thereby forming a regenerated catalyst, and allowing an activated catalyst from the regenerated catalyst to return to the reactor via a regenerated catalyst pipeline; characterized in that, on the regenerated catalyst pipeline, the volume content of oxygen in the gas phase component at the outlet of the regenerated catalyst pipeline is controlled to be less than 0.1%, preferably less than 0.05%, and more preferably less than 0.01%.

Description

Technical Field

[0001] The present invention relates to a method for converting methanol to olefins. Background Art

[0002] Light olefins, defined here as ethylene and propylene, are two important basic chemical raw materials, and their demand is increasing. Ethylene is used to make various polyethylene plastics, vinyl chloride, ethylene oxide, ethylbenzene and ethanol. Propylene is used to make various polypropylene plastics, acrylonitrile and propylene oxide. In addition to cracking petroleum products to obtain light olefins, the preferred conversion process is the process of oxygenates to olefins. When methanol is the main oxygenate, the process is called MTO process.

[0003] In the MTO reactor, under certain conversion conditions, methanol or a mixture of methanol and a diluent is converted into light olefins by contacting with an MTO catalyst. The ideal MTO catalyst is a silicoaluminophosphate (SAPO) molecular sieve catalyst, especially SAPO-34, because it has high selectivity for ethylene and propylene. Document US4499327 has conducted a detailed study on the application of silicoaluminophosphate molecular sieve catalysts in the methanol conversion to olefins process, and believes that SAPO-34 is the preferred catalyst for the MTO process. SAPO-34 catalyst has a high selectivity for light olefins and a high activity, which can make the reaction time of methanol conversion to light olefins reach less than 10 seconds, and even reach the reaction time range of the riser.

[0004] Document US6166282 discloses a technology and reactor for converting methanol into light olefins. A fast fluidized bed reactor is used. After the gas phase completes the reaction in the dense phase reaction zone with a lower gas velocity, it rises to the fast partition with a rapidly decreasing inner diameter, and then a special gas-solid separation device is used to preliminarily separate most of the entrained catalyst. Since the product gas and the catalyst are quickly separated after the reaction, the occurrence of secondary reactions is effectively prevented. According to simulation calculations, compared with the traditional bubbling fluidized bed reactor, the inner diameter of the fast fluidized bed reactor and the required storage capacity of the catalyst are greatly reduced. The carbon-based yield of light olefins in this method is generally around 77%.

[0005] Document CN101357874B discloses a method for producing low-carbon olefins from methanol or dimethyl ether, comprising the following steps: a. providing a fast fluidized bed reactor; b. raw materials including methanol or dimethyl ether enter the fast bed reaction zone of the reactor to contact with a catalyst, and the raw materials are converted into a product stream including ethylene and propylene under effective conditions; c. after the product stream is separated, most of the catalyst enters the second dense phase stripping zone; d. the catalyst entering the second dense phase stripping zone is contacted with a stripping medium to remove the entrained product stream; e. the catalyst after stripping and heat removal is divided into at least two parts, at least the first part is returned to the bottom of the fast bed reaction zone, and at least the second part enters the regenerator.

[0006] Document CN1723262A discloses a multi-stage riser reaction device with a central catalyst loop for the process of converting oxides into light olefins. The device includes multiple riser reactors, a gas-solid separation zone, multiple offset elements, etc. Each riser reactor has a port for injecting catalysts, which are collected in a separation zone to separate the catalyst from the product gas. The carbon-based yield of light olefins in this method is generally between 75% and 80%.

[0007] However, with the increasing market demand for ethylene and propylene, higher requirements are placed on low-carbon olefin production technology. Summary of the invention

[0008] The inventor of the present invention has found that in the reaction-regeneration process of methanol to light olefins, since the reaction and regeneration processes are in different environments, there is a circulation of the catalyst, and the catalyst is a porous solid material, it is inevitable that the medium of one side will be entrained to the other side, thereby affecting the reaction or regeneration process. For example, too much oxygen is brought into the reactor, which will cause the increase of byproducts such as alkynes, dienes, and oxygen-containing compounds. The excessive production of these impurities will seriously affect the separation process; and too much water vapor is brought into the high-temperature regenerator (the regeneration temperature is generally more than 650°C). Due to the existence of excessive temperature difference, the volume of water vapor in the catalyst pores will be sharply enlarged, causing the catalyst to break, increase the content of fine powder, and thus increase the catalyst loss. After a lot of research, the inventor of the present invention has found that by setting a catalyst flow control device on the catalyst pipeline to be regenerated and the regenerated catalyst pipeline connecting the reactor and the regenerator, and reasonably arranging the stripping or degassing equipment, backblowing or loosening the medium before the inlet of the catalyst flow control device, strengthening the stripping and degassing effects, and strictly controlling the amount of oxygen entering the reactor and the amount of water vapor entering the regenerator, the aforementioned problems can be solved. The present invention is completed based on these findings.

[0009] In general, the present invention provides, for example, a method for converting methanol to olefins, which comprises: allowing at least part of the deactivated catalyst produced in the conversion method to enter a regenerator for regeneration, and the regenerated catalyst thus formed is returned to the reactor via a regenerated catalyst pipeline; wherein a second catalyst flow control device is provided on the regenerated catalyst pipeline, and the second catalyst flow control device controls the oxygen volume content in the gas phase component at the outlet of the regenerated catalyst pipeline to be less than 0.1%.

[0010] Preferably, in the above method, the at least partially deactivated catalyst enters the regenerator for regeneration through the catalyst pipeline to be regenerated, and the catalyst pipeline to be regenerated is provided with a first catalyst flow control device, which controls the water vapor volume content in the gas phase component at the outlet of the device to be regenerated to be less than 0.1%.

[0011] Also preferably, in the above method, a stripping medium stripping branch line is provided on the pipeline between the inlet of the regenerated catalyst pipeline and the first catalyst flow control device; a degassing medium degassing branch line is provided on the pipeline between the inlet of the regenerated catalyst pipeline and the second catalyst flow control device.

[0012] For the purposes of the present invention, "at least partially deactivated catalyst" encompasses a fully deactivated catalyst and is therefore used interchangeably with the term "deactivated catalyst" in the present invention.

[0013] Specifically, the present invention provides embodiments such as the following aspects:

[0014] 1. A method for converting methanol to olefins, the method comprising: allowing a feedstock containing methanol to enter a fluidized bed reactor, contacting it with a catalyst, and generating an olefin product, wherein the process causes the catalyst to be at least partially deactivated to form an at least partially deactivated catalyst; allowing a catalyst to be regenerated from the at least partially deactivated catalyst to enter a regenerator for regeneration, thereby forming a regenerated catalyst, and allowing an activated catalyst from the regenerated catalyst to return to the reactor via a regenerated catalyst pipeline; characterized in that

[0015] On the regenerated catalyst pipeline, the volume content of oxygen in the gas phase component at the outlet of the regenerated catalyst pipeline is controlled to be less than 0.1%, preferably less than 0.05%, and more preferably less than 0.01%.

[0016] 2. The method according to embodiment 1, wherein the regenerated catalyst is regenerated in a regenerator through a regenerated catalyst pipeline, and the volume content of water vapor in the gas phase components at the outlet of the regenerated catalyst pipeline is controlled to be less than 0.1%, preferably less than 0.05%, and more preferably less than 0.01%.

[0017] 3. The method according to embodiment 2 is characterized in that additional stripping is performed on the pipeline between the inlet of the pipeline for the regenerated catalyst and the first catalyst flow control device; and / or additional degassing is performed on the pipeline between the inlet of the pipeline for the regenerated catalyst and the second catalyst flow control device.

[0018] 4. The method according to embodiment 3 is characterized in that the medium flow rate is adjusted on each of the stripping medium stripping branch line and the degassing medium degassing branch line, preferably by means of a regulating valve or an orifice plate.

[0019] 5. The method according to any one of the above embodiments, characterized in that:

[0020] The at least partially deactivated catalyst is stripped by at least one stage of stripping medium in a stripper to obtain the catalyst to be regenerated;

[0021] The catalyst to be regenerated enters the regenerator through the catalyst pipeline to be regenerated to obtain the regenerated catalyst;

[0022] The regenerated catalyst is degassed by at least one stage of degassing medium in a degassing tank to obtain the activated catalyst; the activated catalyst is returned to the reactor via the regenerated catalyst pipeline;

[0023] The stripping medium is water vapor, and the degassing medium is water vapor or nitrogen.

[0024] 6. The method according to embodiment 5 is characterized in that the operating conditions of the catalyst pipeline to be regenerated include: temperature 200-500° C., preferably 250-450° C.; catalyst density 50-500 kg / m3, preferably 150-400 kg / m3; volume ratio of water vapor to catalyst to be regenerated 0.001-0.5, preferably 0.01-0.1;

[0025] The operating conditions of the regenerated catalyst pipeline include: temperature 300-700°C, preferably 400-650°C; catalyst density 50-500 kg / m3, preferably 150-400 kg / m3; volume ratio of deaerated medium to regenerated catalyst 0.001-0.5, preferably 0.01-0.1.

[0026] 7. The method according to embodiment 1 is characterized in that the catalyst active component is a silicon-aluminum-phosphorus molecular sieve, and the silicon-aluminum-phosphorus molecular sieve includes SAPO-34.

[0027] 8. An apparatus for implementing the method for converting methanol to olefins according to any one of the preceding embodiments, comprising:

[0028] a fluidized bed reactor for receiving a methanol feedstock and contacting the feedstock with a catalyst to produce an olefin product, wherein the process at least partially deactivates the catalyst to produce an at least partially deactivated catalyst;

[0029] A regenerator, used to regenerate the catalyst to be regenerated from the fluidized bed reactor to obtain a regenerated catalyst;

[0030] a regenerated catalyst line for returning activated catalyst therethrough to the reactor; and

[0031] The second catalyst flow control device disposed on the regenerated catalyst pipeline is configured to control the oxygen volume content in the gas phase component at the outlet of the regenerated catalyst pipeline to be less than 0.1%, preferably less than 0.05%, and more preferably less than 0.01%.

[0032] 9. The device according to embodiment 1 further comprises a catalyst pipeline to be regenerated, which is used to allow the deactivated catalyst to enter the regenerator for regeneration. A first catalyst flow control device is provided on the catalyst pipeline to be regenerated, and the device is configured to control the volume content of water vapor in the gas phase component at the outlet of the catalyst pipeline to be regenerated to be less than 0.1%, preferably less than 0.05%, and more preferably less than 0.01%.

[0033] 10. The device according to embodiment 9 is characterized in that a stripping medium stripping branch line is provided on the pipeline between the inlet of the pipeline for the regenerated catalyst and the first catalyst flow control device for additional stripping; a degassing medium degassing branch line is provided on the pipeline between the inlet of the pipeline for the regenerated catalyst and the second catalyst flow control device for additional degassing.

[0034] 11. The device according to embodiment 9, further comprising:

[0035] A stripper, used for performing at least one stage of stripping of the at least partially deactivated catalyst with a stripping medium to obtain the spent catalyst;

[0036] A degassing tank, used for degassing the regenerated catalyst through at least one stage of degassing medium in the degassing tank to obtain the activated catalyst;

[0037] It is characterized in that the stripper inlet is connected to the separation zone of the reactor, and the stripper outlet is connected to the inlet of the pipeline for the regenerated catalyst; the degassing tank inlet is connected to the dilute phase section of the regenerator, and the degassing tank outlet is connected to the inlet of the pipeline for the regenerated catalyst.

[0038] In an exemplary embodiment of the present invention, the stripper is disposed inside the reactor. In another exemplary embodiment of the present invention, the stripper is disposed outside the reactor.

[0039] In an exemplary embodiment of the present invention, the degassing tank is disposed inside the regenerator. In another exemplary embodiment of the present invention, the degassing tank is disposed outside the regenerator.

[0040] In a preferred embodiment of the present invention, at least one layer of baffles is provided in the stripper, at least one layer of baffles is provided in the degassing tank, and the degassing medium enters the degassing tank in sections.

[0041] 12. The device according to embodiment 11 is characterized in that a gas phase outlet is provided at the top of the stripper and is connected to the separation zone of the reactor, and a gas phase outlet is provided at the top of the degassing tank and is connected to the dilute phase section of the regenerator or the flue gas duct of the regenerator outlet.

[0042] 13. The device according to embodiment 9 is characterized in that the first catalyst flow control device and the second catalyst flow control device are each independently a pneumatic or hydraulic one-way slide valve.

[0043] 14. The device according to embodiment 8 is characterized in that the fluidized bed reactor is a dense phase, turbulent or fast fluidization type.

[0044] Technical Effects

[0045] According to the method of the present invention, the product has less impurities.

[0046] According to the method of the present invention, the catalyst loss is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of the process of the present invention.

[0048] Figure 1 middle,

[0049] 1 is the reactor raw material feed;

[0050] 2 is the reaction zone of the reactor;

[0051] 3 is the gas-solid rapid separation zone;

[0052] 4 is a stripper;

[0053] 5 is an inclined tube for external circulation of the reactor;

[0054] 6 is a raw material distribution plate;

[0055] 7 is a regeneration zone of the regenerator;

[0056] 8 is a gas-solid cyclone separator for the reactor;

[0057] 9 is a reactor separation zone;

[0058] 10 is a gas collecting chamber;

[0059] 11 is a product gas outlet pipeline;

[0060] 12 is a dilute phase section of the regenerator;

[0061] 13 is a regeneration medium inlet pipeline;

[0062] 14 is a pipeline for the catalyst to be produced (or an inclined pipe to be produced);

[0063] 15 is a regenerator external heat exchanger;

[0064] 16 is a gas-solid cyclone separator of the regenerator;

[0065] 17 is a regeneration flue gas outlet pipeline;

[0066] 18 is a heat collector outside the reactor;

[0067] 19 is a regeneration catalyst pipeline (or a regeneration inclined tube);

[0068] 20 is a pipeline for water vapor to enter the reactor;

[0069] 21 is a regenerator;

[0070] 22 is a reactor;

[0071] 23 is a combustion oil inlet pipeline;

[0072] 24 is a catalyst inlet / outlet pipeline at the bottom of the regenerator;

[0073] 25 is an auxiliary heating furnace;

[0074] 26 is a second catalyst flow control device (regeneration inclined tube slide valve);

[0075] 27 is a first catalyst flow control device (a slide valve of an inclined tube to be produced);

[0076] 28 degassing tank;

[0077] 29 stripping medium stripping branch line;

[0078] 30 Degassing medium degassing branch line. DETAILED DESCRIPTION

[0079] The specific embodiments of the present invention are described in detail below, but it should be pointed out that the protection scope of the present invention is not limited by these specific embodiments, but is determined by the claims in the appendix.

[0080] All publications, patent applications, patents and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings conventionally understood by those skilled in the art. In the event of a conflict, the definitions in this specification shall prevail.

[0081] When this specification uses the prefix "well-known to those skilled in the art", "prior art" or similar terms to introduce materials, substances, methods, steps, devices or components, etc., the objects introduced by the prefix cover those commonly used in the art when this application is filed, but also include those that are not commonly used at present but will become recognized in the art as being suitable for similar purposes.

[0082] In the context of this specification, the preparation method of SAPO molecular sieve or SAPO molecular sieve catalyst is well known in the art.

[0083] In the context of the present specification, the term "at least partially deactivated catalyst" or "deactivated catalyst" as used herein refers to a catalyst whose reaction activity has at least partially decreased after passing through a reaction zone.

[0084] In the context of this specification, the term "spent catalyst" as used herein refers to the catalyst that is taken from the reactor and sent (eg, via a spent catalyst line) to the regenerator for regeneration.

[0085] In the context of this specification, the term "regenerated catalyst" is used to refer to the catalyst obtained after regeneration in the regeneration zone of a regenerator, for example by combustion of coke.

[0086] In the context of this specification, the term "activated catalyst" is used to refer to the catalyst which, after regeneration and optional other treatments in the regenerator (ie, regeneration is complete), is sent (eg, via a regenerated catalyst line) to the reactor for reaction.

[0087] Unless otherwise specified, all percentages, parts, ratios, etc. mentioned in this specification are based on weight and pressure is gauge pressure.

[0088] In the context of this specification, any two or more embodiments of the present invention may be arbitrarily combined, and the technical solutions thus formed belong to part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0089] An exemplary embodiment A of the present invention is as follows Figure 1 See Figure 1, the logistics including methanol raw material enters the reaction zone 2 of the reactor 22 through the feed pipeline 1 and optionally passes through the raw material distribution plate 6, contacts with the molecular sieve catalyst, and reacts to generate products containing light olefins, wherein the catalyst is at least partially deactivated. The at least partially deactivated catalyst enters the reactor separation zone 9 through the gas-solid rapid separation zone 3, wherein most of the at least partially deactivated catalyst separated by the gas-solid rapid separation device 3 enters the stripper 4, and the gas phase product separated by the gas-solid rapid separation device 3 and part of the at least partially deactivated catalyst not separated by the gas-solid rapid separation device enter the cyclone separator 8 for separation and re-separation. The at least partially deactivated catalyst separated by the cyclone separator 8 is also returned to the stripper 4 through the feed leg of the cyclone separator 8. The gas phase product separated by the gas-solid rapid separation device 3 and the gas phase product separated by the cyclone separator 8 enter the subsequent separation section through the gas collecting chamber 10 and the outlet pipeline 11.

[0090] The at least partially deactivated catalyst separated by the gas-solid rapid separation zone 3 and the cyclone separator 8 is stripped to obtain a regenerated catalyst, which is divided into two parts, one part is returned to the bottom of the reaction zone 2 through the catalyst external circulation inclined pipe 5; the other part enters the regenerator 21 through the regenerated catalyst pipeline 14. The regenerated catalyst pipeline 14 is provided with a first catalyst flow control device 27, which is configured to control the water vapor volume content in the gas phase component at the outlet of the regenerated catalyst pipeline to be less than 0.1%, preferably less than 0.05%, and more preferably less than 0.01%.

[0091] The catalyst to be regenerated is regenerated in the regeneration zone 7 of the regenerator 21. The regeneration medium used can be those conventionally used in the art, such as air, oxygen, etc., and the regeneration is preferably carried out by burning coke to obtain a regenerated catalyst. The flue gas generated by the combustion of coke passes through the cyclone separator 16 and enters the subsequent energy recovery system through the flue gas outlet pipeline 17. The regenerated catalyst enters the degassing tank 28 connected to the dilute phase section 12 at the top of the regenerator 21, and is degassed by at least one stage of degassing medium in the degassing tank 28 to obtain the activated catalyst. The activated catalyst returns to the reaction zone 2 of the reactor through the regenerated catalyst pipeline 19. A second catalyst flow control device 26 is provided on the regenerated catalyst pipeline 19, which is configured to control the oxygen volume content in the gas phase component at the outlet of the regenerated catalyst pipeline to be less than 0.1%, preferably less than 0.05%, and more preferably less than 0.01%.

[0092] In the above embodiment A, preferably, the steam entering the reactor pipeline 20 is equipped with an auxiliary heating furnace 25, and the pipeline is merged with the feed pipeline 1 and enters the reactor 22. According to the present invention, for example, one of the functions of the steam entering the steam pipeline 20 is to be used for start-up heating; accordingly, the auxiliary heat furnace 25 assists in reaching the reaction start-up temperature when feeding.

[0093] In the above-mentioned embodiment A, preferably, the catalyst external circulation inclined tube 5 of the reactor 22 is equipped with a reactor external heat extractor 5 for removing the heat released by the reaction in the reactor to achieve the purpose of controlling the reaction temperature required in the reaction zone.

[0094] In the above-mentioned embodiment A, preferably, the bottom of the regenerator 21 is equipped with a catalyst inlet / outlet pipeline 24 for introducing the catalyst into the regenerator during startup or normal operation or for exporting the catalyst from the regenerator during shutdown.

[0095] In the above embodiment A, preferably, the regeneration medium is added to the regenerator 21 through the regeneration medium inlet pipeline 13 ; and the combustion oil is added to the regenerator 21 through the combustion oil inlet pipeline 23 .

[0096] In the above-mentioned embodiment A, preferably, the regenerator 21 is equipped with a regenerator external heat extractor 15 for removing the heat released by the reaction in the regenerator 21, so as to achieve the purpose of controlling the required regeneration temperature of the regenerator.

[0097] In one embodiment of the present invention, optionally, a group of steam stripping branches are provided at intervals on the pipeline between the inlet of the catalyst pipeline to be generated and the catalyst flow control device, and each group of steam stripping branches is arranged around the pipeline.

[0098] In one embodiment of the present invention, optionally, a group of degassing medium degassing branches are provided at intervals on the pipeline between the regeneration catalyst pipeline inlet and the catalyst flow control device, and each group of degassing medium degassing branches is arranged around the pipeline.

[0099] In one embodiment of the present invention, optionally, orifice plates are provided on both the steam stripping branch line and the degassing medium degassing branch line, and the orifice plate size is selected according to the design to fix the medium flow of each branch line without manual adjustment, and a switch valve is provided on each branch line.

[0100] In one embodiment of the present invention, optionally, the stripping medium stripping branch line and the degassing medium degassing branch line not only have a loosening effect, but also have an additional stripping or degassing effect.

[0101] The present invention will be described illustratively by way of examples below, but they do not limit the scope of protection of the present invention.

[0102] [Example 1]

[0103] See also Figure 1 , using exemplary embodiment A of the present invention.

[0104] The active component of the catalyst is a silicon-aluminum-phosphorus molecular sieve, and the silicon-aluminum-phosphorus molecular sieve includes SAPO-34. The fluidized bed reactor is a fast fluidized type. The catalyst flow control device is a pneumatic one-way slide valve. The catalyst in the reactor that is at least partially deactivated is stripped by a primary stripping medium. The catalyst to be regenerated enters the regenerator through the catalyst pipeline to be regenerated for regeneration. The regenerated catalyst is degassed by a degassing medium. The activated catalyst that has been regenerated returns to the reactor through the regenerated catalyst pipeline. The stripping medium is water vapor, and the degassing medium is water vapor. The stripping process is completed in the stripper, the stripper inlet is connected to the reactor, and the stripper outlet is connected to the inlet of the catalyst pipeline to be regenerated. The degassing process is completed in the degassing tank, and the degassing tank is arranged inside the regenerator. The inlet of the degassing tank is connected to the regenerator, and the outlet of the degassing tank is connected to the inlet of the regenerated catalyst pipeline. A steam stripping branch line is provided on the pipeline between the inlet of the catalyst pipeline to be regenerated and the catalyst flow control device, and the steam stripping branch line is arranged around the pipeline. A degassing medium degassing branch line is provided on the pipeline between the inlet of the regenerated catalyst pipeline and the catalyst flow control device, and the degassing medium degassing branch line is arranged around the pipeline. Orifice plates are provided on the steam stripping branch line and the degassing medium degassing branch line, and each branch line is provided with a switch valve. There are 5 layers of baffles in the stripper, which are arranged in a staggered manner. There are 2 layers of baffles in the degassing tank, and the degassing medium enters the degassing tank in two sections. A gas phase outlet is provided at the top of the stripper to connect to the reactor body, and a gas phase outlet is provided at the top of the degassing tank to connect to the dilute phase section of the regenerator.

[0105] The operating conditions of the regenerated catalyst pipeline are: temperature 200°C, catalyst density 50 kg / m3, and volume ratio of water vapor to regenerated catalyst 0.5; the operating conditions of the regenerated catalyst pipeline are: temperature 300°C, catalyst density 50 kg / m3, and volume ratio of deaerated medium to regenerated catalyst 0.5. The volume content of water vapor in the gas phase component at the outlet of the catalyst flow control device on the regenerated catalyst pipeline is 0.05%, and the volume content of oxygen in the gas phase component at the outlet of the catalyst flow control device on the regenerated catalyst pipeline is 0.005%.

[0106] After analysis, the mass fraction of oxygen-containing compounds (the sum of aldehydes, ketones, and acids) in the reactor outlet product gas was less than 100 ppm, the mass fraction of acetylene was less than 1 ppm, and the catalyst loss was reduced by 4% within 3 months.

[0107] [Example 2]

[0108] Except as specifically noted below, the conditions and steps described in [Example 1] are basically followed. The fluidized bed reactor is a dense phase fluidization type. The catalyst flow control device is a hydraulic one-way slide valve. The catalyst in the reactor that is at least partially deactivated is stripped by a two-stage stripping medium. The degassing medium is nitrogen. The stripper is provided with two layers of baffles, which are arranged in a staggered manner. The degassing tank is provided with four layers of baffles, and the degassing medium enters the degassing tank in two sections. A gas phase outlet is provided at the top of the degassing tank, which is connected to the flue gas duct at the outlet of the regenerator.

[0109] The operating conditions of the regenerated catalyst pipeline are: temperature 490°C, catalyst density 480 kg / m3, and volume ratio of water vapor to regenerated catalyst 0.002; the operating conditions of the regenerated catalyst pipeline are: temperature 680°C, catalyst density 460 kg / m3, and volume ratio of deaerated medium to regenerated catalyst 0.003. The volume content of water vapor in the gas phase component at the outlet of the catalyst flow control device on the regenerated catalyst pipeline is 0.03%, and the volume content of oxygen in the gas phase component at the outlet of the catalyst flow control device on the regenerated catalyst pipeline is 0.008%.

[0110] After analysis, the mass fraction of oxygen-containing compounds in the reactor outlet product gas was less than 50ppm, the mass fraction of acetylene was less than 1ppm, and the catalyst loss was reduced by 6% within 3 months.

[0111] [Example 3]

[0112] According to the conditions and steps described in [Example 1], the operating conditions of the catalyst pipeline to be regenerated are: temperature 400°C, catalyst density 380 kg / m3, and the volume ratio of water vapor to the catalyst to be regenerated is 0.01; the operating conditions of the regenerated catalyst pipeline are: temperature 630°C, catalyst density 380 kg / m3, and the volume ratio of the deaerated medium to the regenerated catalyst is 0.01. The volume content of water vapor in the gas phase component at the outlet of the catalyst flow control device on the catalyst pipeline to be regenerated is 0.01%, and the volume content of oxygen in the gas phase component at the outlet of the catalyst flow control device on the catalyst pipeline to be regenerated is 0.01%.

[0113] After analysis, it was found that the mass fraction of oxygen-containing compounds in the reactor outlet product gas was less than 150ppm, the mass fraction of acetylene was less than 1ppm, and the catalyst loss was reduced by 10% within 3 months.

[0114] [Example 4]

[0115] According to the conditions and steps described in [Example 1], the operating conditions of the catalyst pipeline to be regenerated are: temperature 480°C, catalyst density 450 kg / m3, and the volume ratio of water vapor to the catalyst to be regenerated is 0.005; the operating conditions of the regenerated catalyst pipeline are: temperature 670°C, catalyst density 380 kg / m3, and the volume ratio of the deaerated medium to the regenerated catalyst is 0.005. The volume content of water vapor in the gas phase component at the outlet of the catalyst flow control device on the catalyst pipeline to be regenerated is 0.001%, and the volume content of oxygen in the gas phase component at the outlet of the catalyst flow control device on the catalyst pipeline to be regenerated is 0.0004%.

[0116] After analysis, the mass fraction of oxygen-containing compounds in the reactor outlet product gas was less than 40ppm, the mass fraction of acetylene was less than 1ppm, and the catalyst loss was reduced by 15% within 3 months.

[0117] [Comparative Example 1]

[0118] According to the steps described in [Example 1], the volume content of water vapor in the gas phase components at the outlet of the catalyst flow control device on the pipeline for regenerated catalyst is 0.21%, and the volume content of oxygen in the gas phase components at the outlet of the catalyst flow control device on the pipeline for regenerated catalyst is 0.18%.

[0119] The mass fraction of oxygen-containing compounds in the product gas at the reactor outlet reached 308ppm, and the mass fraction of acetylene reached 3ppm.

[0120] Obviously, the method of the present invention can achieve the purpose of increasing the yield of light olefins, and can be used in the industrial production of light olefins.

Claims

1. A method for converting methanol to olefins, the method comprising: Passing a feedstock comprising methanol into a fluidized bed reactor and contacting the feedstock with a catalyst to produce an olefin product, wherein the process at least partially deactivates the catalyst to form an at least partially deactivated catalyst; The catalyst to be regenerated from the at least partially deactivated catalyst is allowed to enter the regenerator for regeneration, thereby forming a regenerated catalyst, and the activated catalyst from the regenerated catalyst is returned to the reactor via a regenerated catalyst pipeline; characterized in that, The catalyst to be regenerated is allowed to enter the regenerator through the catalyst pipeline to be regenerated, a first catalyst flow control device is arranged on the catalyst pipeline to be regenerated, and a stripping medium stripping branch line is arranged on the pipeline between the inlet of the catalyst pipeline to be regenerated and the first catalyst flow control device, and the volume content of water vapor in the gas phase component at the outlet of the catalyst pipeline to be regenerated is controlled to be less than 0.05%, a second catalyst flow control device is arranged on the regenerated catalyst pipeline, and a degassing medium degassing branch line is arranged on the pipeline between the inlet of the regenerated catalyst pipeline and the second catalyst flow control device, so as to control the volume content of oxygen in the gas phase component at the outlet of the regenerated catalyst pipeline to be less than 0.01%.

2. The method according to claim 1, wherein the volume content of water vapor in the gas phase components at the outlet of the spent catalyst pipeline is controlled to be less than 0.01%.

3. The method according to claim 2, characterized in that Additional stripping is performed on the pipeline between the inlet of the pipeline for the regenerated catalyst and the first catalyst flow control device; and / or additional degassing is performed on the pipeline between the inlet of the pipeline for the regenerated catalyst and the second catalyst flow control device.

4. The method according to claim 3, characterized in that The medium flow rates are adjusted on the stripping medium stripping branch line and the degassing medium degassing branch line respectively.

5. A method according to any one of the preceding claims, characterised in that The at least partially deactivated catalyst is stripped by at least one stage of stripping medium in a stripper to obtain the catalyst to be regenerated; The catalyst to be regenerated enters the regenerator through the catalyst pipeline to be regenerated to obtain the regenerated catalyst; The regenerated catalyst is degassed by at least one stage of degassing medium in a degassing tank to obtain the activated catalyst; the activated catalyst is returned to the reactor via the regenerated catalyst pipeline; The stripping medium is water vapor, and the degassing medium is water vapor or nitrogen.

6. The method according to claim 5, characterized in that The operating conditions of the catalyst pipeline to be regenerated include: temperature 200-500°C; catalyst density 50-500 kg / m3; volume ratio of water vapor to catalyst to be regenerated 0.001-0.5; The operating conditions of the regenerated catalyst pipeline include: temperature of 300-700° C.; catalyst density of 50-500 kg / m 3 ; and volume ratio of deaerated medium to regenerated catalyst of 0.001-0.

5.

7. The method according to claim 1, characterized in that The catalyst active component is a silicon-aluminum-phosphorus molecular sieve, and the silicon-aluminum-phosphorus molecular sieve includes SAPO-34.

8. The method according to claim 1, characterized in that The operating conditions of the catalyst pipeline to be regenerated include: temperature 250-450°C; catalyst density 150-400 kg / m3; volume ratio of water vapor to catalyst to be regenerated 0.01-0.1; The operating conditions of the regenerated catalyst pipeline include: temperature of 400-650° C.; catalyst density of 150-400 kg / m 3 ; and volume ratio of deaerated medium to regenerated catalyst of 0.01-0.

1.

9. An apparatus for implementing the methanol to olefin conversion method according to any one of claims 1 to 8, comprising: a fluidized bed reactor for receiving a methanol feedstock and contacting the feedstock with a catalyst to produce an olefin product, wherein the process at least partially deactivates the catalyst to produce an at least partially deactivated catalyst; A regenerator, used to regenerate the catalyst to be regenerated from the fluidized bed reactor to obtain a regenerated catalyst; a regenerated catalyst pipeline for returning the activated catalyst to the reactor; and A second catalyst flow control device is arranged on the regenerated catalyst pipeline, and a degassing medium degassing branch line for additional degassing is arranged on the pipeline between the inlet of the regenerated catalyst pipeline and the second catalyst flow control device, and the device is configured to control the oxygen volume content in the gas phase component at the outlet of the regenerated catalyst pipeline to be less than 0.01%, It further comprises a catalyst pipeline to be regenerated, which is used to allow the deactivated catalyst to enter the regenerator for regeneration. A first catalyst flow control device is arranged on the catalyst pipeline to be regenerated, and a stripping medium stripping branch line is arranged on the pipeline between the inlet of the catalyst pipeline to be regenerated and the first catalyst flow control device. The device is configured to control the volume content of water vapor in the gas phase component at the outlet of the catalyst pipeline to be regenerated to be less than 0.05%.

10. The device according to claim 9, further comprising: A stripper, used for performing at least one stage of stripping of the at least partially deactivated catalyst with a stripping medium to obtain the spent catalyst; A degassing tank, used for degassing the regenerated catalyst through at least one stage of degassing medium in the degassing tank to obtain the activated catalyst; It is characterized in that The stripper inlet is connected to the separation zone of the reactor, and the stripper outlet is connected to the inlet of the catalyst pipeline to be regenerated; the degassing tank inlet is connected to the dilute phase section of the regenerator, and the degassing tank outlet is connected to the inlet of the regenerated catalyst pipeline.

11. The device according to claim 10, characterized in that The stripper has a gas phase outlet at the top connected to the separation zone of the reactor, and the degassing tank has a gas phase outlet at the top connected to the dilute phase section of the regenerator or the flue gas duct at the regenerator outlet.

12. The device according to claim 9, characterized in that The first catalyst flow control device and the second catalyst flow control device are each independently a pneumatic or hydraulic one-way slide valve.

13. The device according to claim 9, characterized in that The fluidized bed reactor is of dense phase, turbulent or fast fluidization type.

14. The device according to claim 9, characterized in that The device is configured to control the water vapor volume content in the gas phase components at the outlet of the spent catalyst pipeline to be less than 0.01%.

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