A system and method for conveying regenerated catalyst

Abstract

The application discloses a system and method for conveying regenerated catalyst, and the system comprises: a regenerator for regenerating reaction catalyst from a reactor; a heat exchanger for balancing the temperature of the reaction catalyst and the regenerated catalyst; a cyclone separation unit for removing catalyst particles entrained in regenerated flue gas of the regenerator and returning the catalyst particles to the regenerator; a conveying cyclone separator for gas-solid separation of the regenerated catalyst from the heat exchanger; the application reduces the temperature of the regenerated catalyst before returning to the reactor, reduces the gas phase pressure in the regenerated catalyst conveying pipe, facilitates the degassing of the regenerated catalyst in the subsequent process, and enables the stable conveying of the regenerated catalyst; meanwhile, the high-temperature difference catalyst heat exchange between the two devices eliminates the impact of the high-temperature regenerated catalyst on the reaction environment, and is favorable for improving the product distribution in the reactor and the charring in the regenerator, so that the fluidization between the reactor and the regenerator is more uniform and effective.

Description

Technical Field

[0001] This invention belongs to the field of catalyst regeneration technology and relates to a system and method for transporting regenerated catalysts. It is applicable to fluidized bed regeneration systems, and is particularly applicable to coal chemical, methanol-to-hydrocarbon and catalytic cracking processes. Background Technology

[0002] In the chemical industry, coal chemical, methanol chemical and catalytic cracking processes often adopt continuous "reaction-regeneration" circulating fluidized bed technology as an important means of producing chemical products. It is also an important link in realizing the production of hydrocarbons by replacing petroleum with other resources.

[0003] With the rapid development of catalyst technology, the selectivity of catalysts to products is increasing, production efficiency is gradually improving, the carbon content of catalysts increases in the continuous "reaction-regeneration" process, the catalyst circulation volume decreases accordingly, and the catalyst delivery method is further changing.

[0004] In traditional continuous "reaction-regeneration" circulating fluidized bed processes, the regenerated catalyst is mostly transported back to the reactor via gravity through a regeneration riser. A loosening medium inlet is typically installed in the regeneration riser to ensure the catalyst is transported in a fluidized state. A regeneration slide valve is also installed on the regeneration riser to control the flow rate of the regenerated catalyst. However, when the catalyst properties or production requirements change, or when the gas phase flow rate cannot be effectively controlled, the regenerated catalyst transport method will change with the varying transport volume under different operating conditions. When the regenerated catalyst transport method in the regeneration riser transitions between dilute and dense phase transport, or when there is a significant difference in transport density, fluctuations in the pressure difference before and after the regeneration slide valve can easily lead to catalyst blockage near the regeneration slide valve. This also causes fluctuations in the amount of regenerated catalyst returned to the reactor, thus affecting the main reaction and product distribution. In some processes, although degassing lines or degassing tanks are introduced between the regeneration risers to attempt to eliminate the impact of gas phase changes on catalyst transport, the improvement in catalyst transport is very limited due to insufficient degassing space or short degassing time.

[0005] On the other hand, since the temperature difference between the regeneration temperature and the reaction temperature is often between 150 and 190°C, the high-temperature regeneration catalyst, upon entering the reactor, will impact the reaction environment, causing localized high temperatures in the reactor and affecting the normal reaction process. In some processes, although external heat exchangers are used to recover the heat from the high-temperature regeneration catalyst, water or steam is introduced as the heat exchange medium. This not only increases long-term operating costs, but also necessitates immediate shutdown and repair in the event of leaks, dry burning, or other accidents. Delayed shutdown can lead to the escalation of the accident. Conversely, the lower-temperature reaction catalyst, upon entering the regenerator, cannot immediately reach the regeneration temperature, affecting regeneration and coking, and negatively impacting the fluidization of both reactors. Summary of the Invention

[0006] The purpose of this invention is to provide a system and method for transporting regenerated catalysts, so as to enable the smooth transport of regenerated catalysts.

[0007] To achieve one aspect of the above-mentioned objective, the system for transporting regenerated catalyst provided by the present invention adopts the following technical solution:

[0008] A system for delivering a regenerated catalyst, comprising:

[0009] A regenerator, connected to a reaction catalyst inlet and a regenerated catalyst outlet, is used to regenerate the reaction catalyst from the reactor; the reaction catalyst inlet is used to feed the reaction catalyst into the regenerator, and the regenerated catalyst outlet is used to feed the regenerated catalyst out of the regenerator.

[0010] A heat exchanger is used to balance the temperatures of the reaction catalyst and the regenerated catalyst. The heat exchanger includes a tube side and a shell side. The tube side inlet is connected to the reactor via a reaction catalyst delivery pipe, and a reaction slide valve is installed on the reaction catalyst delivery pipe. The tube side outlet is connected to the regenerator via the reaction catalyst inlet. The shell side inlet is connected to the regenerator via the regenerated catalyst outlet. The shell side outlet is connected to a conveying cyclone separator via a first branch pipe, and a conveying inlet valve is installed on the first branch pipe. The shell side of the heat exchanger is also connected to a nitrogen source via a fluidized nitrogen inlet.

[0011] A cyclone separation unit is provided inside the regenerator to remove catalyst particles entrained in the regenerated flue gas of the regenerator and return it to the regenerator.

[0012] A conveying cyclone separator is provided, wherein the inlet of the conveying cyclone separator is connected to the shell-side outlet via the first branch pipe, and is used to perform gas-solid separation on the regenerated catalyst from the heat exchanger; the catalyst outlet of the conveying cyclone separator is connected to a regenerated catalyst conveying pipe, a regeneration slide valve is provided on the regenerated catalyst conveying pipe, and the nitrogen source is connected to the regenerated catalyst conveying pipe downstream of the regeneration slide valve via a nitrogen inlet.

[0013] According to the system of the present invention, preferably, the gas phase outlet of the conveying cyclone separator is connected to the cyclone separation unit so as to send the gas phase separated by the conveying cyclone separator and the regenerated flue gas of the regenerator together into the cyclone separation unit for gas-solid separation.

[0014] According to the system of the present invention, preferably, the cyclone separation unit includes a primary cyclone separator and a secondary cyclone separator; wherein, the primary cyclone separator is connected to the interior of the regenerator and the gas phase outlet of the conveying cyclone separator via the primary cyclone separator inlet, and the gas phase outlet of the primary cyclone separator is connected to the secondary cyclone separator via the secondary cyclone separator inlet.

[0015] According to the system of the present invention, preferably, the shell-side outlet of the heat exchanger is also connected via a second branch pipe to the regeneration catalyst delivery pipe between the conveying cyclone separator and the regeneration slide valve, and a bypass valve is provided on the second branch pipe.

[0016] According to the system of the present invention, preferably, the heat exchanger is arranged longitudinally, and a built-in multi-nozzle annulus is provided in the lower part of its shell side, and the fluidizing nitrogen inlet is connected to the multi-nozzle annulus; preferably, one or more radial baffles are also provided in the shell side, and the multi-nozzle annulus is disposed at the connection between the baffle and the shell side wall to improve the heat exchange fluidization effect.

[0017] To achieve the aforementioned objective, the present invention also provides a method for transporting a regenerated catalyst using the aforementioned system, the method comprising:

[0018] The reaction catalyst from the reaction catalyst delivery pipe first exchanges heat with the regenerated catalyst in a heat exchanger, and then enters the regenerator for regeneration. The regenerated catalyst obtained after regeneration enters the heat exchanger from the regenerator, is atomized by nitrogen gas from the fluidizing nitrogen inlet and exchanges heat with the reaction catalyst, and then enters the conveying cyclone separator for gas-solid separation. The separated regenerated catalyst enters the regenerated catalyst delivery pipe and is atomized by nitrogen gas from the conveying nitrogen inlet before being sent out.

[0019] According to the method of the present invention, preferably, the method further includes: sending the gas phase separated from the conveying cyclone separator and the regenerated flue gas from the regenerator together into the cyclone separation unit for gas-solid separation, so as to remove the catalyst particles entrained therein and send them back to the regenerator.

[0020] According to the method of the present invention, preferably, the regenerator is a continuous circulating fluidized bed regenerator; the diameter of the reaction catalyst is 1-500 μm, preferably 5-150 μm; the regeneration temperature is 550-750℃, preferably 630-690℃; and the regeneration pressure is 0.03-0.18 MPa, preferably 0.05-0.1 MPa.

[0021] According to the method of the present invention, preferably, the amount of nitrogen introduced into the shell side of the heat exchanger through the fluidized nitrogen inlet is 50-1000 Nm³. 3 / h, preferably 80~400Nm 3 / h;

[0022] According to the method of the present invention, preferably, the linear velocity of the regenerated catalyst entering the conveying cyclone separator is 5 to 25 m / s, more preferably 12 to 22 m / s;

[0023] According to the method of the present invention, preferably, the separated regenerated catalyst is fed from the lower part of the conveying cyclone separator to a reactor, such as a methanol-to-olefins reactor, via the regenerated catalyst conveying pipe, wherein the conveying density of the regenerated catalyst in the regenerated catalyst conveying pipe is 100–400 kg / m³. 3 The preferred value is 150–350 kg / m³. 3 .

[0024] According to the method of the present invention, preferably, a cascade automatic control is provided between the regeneration slide valve and the delivery inlet valve, and a density meter is installed on the first branch pipe after the delivery inlet valve. When the delivery density of the regeneration catalyst in the first branch pipe is between 150 and 350 kg / m³, a density meter is installed. 3 When the flow rate varies within a certain range, the opening degree of the regeneration slide valve and the delivery inlet valve is automatically controlled inversely between 95% and 5% to control the flow rate and delivery density of the regenerated catalyst.

[0025] According to the method of the present invention, preferably, in the case of shutdown, the inlet valve is closed and the bypass valve is opened, so that the regenerated catalyst, after leaving the shell side of the heat exchanger, enters the regenerated catalyst delivery pipe through the second branch pipe and finally returns to the reactor, until the reactor and regenerator discharge all the catalyst.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] This invention first adds a heat exchange process between the regenerated catalyst and the reaction catalyst during the transport process. By taking advantage of the large temperature difference between the two catalysts, the temperature at the end point of each catalyst is balanced, which can not only ensure the stability of the reaction environment, but also improve the regeneration coking situation. Then, by using the principle of cyclone separation, the gas-solid separation of the regenerated catalyst is controlled during the cyclone separation process, so that the regenerated catalyst can be stably and continuously transported back to the reactor, improving the fluidization state of the two reactors.

[0028] By introducing equipment and processes to control the catalyst delivery rate and density in the regeneration riser, the influence of unstable catalyst and gas phase density on the delivery method during the regeneration catalyst delivery process is eliminated. By reducing the temperature of the regenerated catalyst before it returns to the reactor, the gas phase pressure in the regenerated catalyst delivery pipe is reduced, facilitating degassing of the regenerated catalyst in subsequent processes and ensuring stable delivery of the regenerated catalyst. Simultaneously, through high-temperature catalyst heat exchange between the two reactors, the temperature of the regenerated catalyst is balanced, eliminating the impact of high-temperature regenerated catalyst on the reaction environment, improving product distribution in the reactor and reducing coking in the regenerator, resulting in more uniform and efficient fluidization in both reactors.

[0029] Compared with traditional conveying methods, this invention has the advantages of stable conveying density, balanced conveying temperature, controllable degassing degree, and high operational flexibility. At the same time, it can also realize automatic control of conveying volume according to different working conditions and production conditions. Compared with traditional conveying processes, this method can effectively reduce product consumption by 0.5-1% and catalyst consumption by 6-10%. Attached Figure Description

[0030] Figure 1 This is a schematic diagram illustrating one embodiment of the system of the present invention;

[0031] Figure 2 A schematic diagram of the system for comparison;

[0032] Explanation of reference numerals in the attached figures:

[0033] 1-Regenerator; 2-Heat Exchanger; 3-Conveying Cyclone Separator; 4-First-Stage Cyclone Separator; 5-Second-Stage Cyclone Separator; 6-Reaction Catalyst Delivery Pipe; 7-Reaction Catalyst Inlet; 8-Regenerated Catalyst Outlet; 9-Shell-Side Outlet; 10-Nitrogen Source; 11-Regenerated Catalyst Delivery Pipe; 12-Gas Phase Outlet; 13-Second-Stage Cyclone Separator Inlet; 14-Second-Stage Cyclone Separator Outlet; 15-Reaction Slide Valve; 16-Regeneration Slide Valve; 17-First-Stage Cyclone Separator Inlet; 18-Conveying Inlet Valve; 19-Bypass Valve;

[0034] 91-First branch pipe; 92-Second branch pipe; 101-Fluidized nitrogen inlet; 102-Nitrogen delivery inlet. Detailed Implementation

[0035] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0036] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of the invention described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0037] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0038] like Figure 1 As shown, the system of the present invention includes a regenerator 1, a cyclone separation unit, a heat exchanger 2, and a conveying cyclone separator 3; wherein, the regenerator 1 is connected to a reaction catalyst inlet 7 and a regenerated catalyst outlet 8, and is used to regenerate the reaction catalyst from the reactor; the reaction catalyst inlet 7 is used to convey the reaction catalyst into the regenerator, and the regenerated catalyst outlet 8 is used to convey the regenerated catalyst out of the regenerator 1.

[0039] The cyclone separation unit is disposed within the regenerator 1 and is used to remove catalyst particles entrained in the regenerated flue gas of the regenerator 1 and return them to the regenerator 1. In one embodiment, the cyclone separation unit includes a primary cyclone separator 4 and a secondary cyclone separator 5; wherein the primary cyclone separator 4 is connected to the interior 312 of the regenerator 1 via a primary cyclone separator inlet 17, and the gas phase outlet of the primary cyclone separator 4 is connected to the secondary cyclone separator 5 via a secondary cyclone separator inlet 13. In some embodiments, the internal space of the regenerator 1 is provided with multiple sets, such as 12 to 16 sets, of primary cyclone separators 4 and secondary cyclone separators 5 connected in series, for recovering catalyst from the regenerated flue gas.

[0040] The heat exchanger 2 is used to balance the temperature of the reaction catalyst and the regenerated catalyst (i.e., reduce the temperature difference between them); the heat exchanger 2 includes a tube side (or the heated side) and a shell side (or the heating side). Its tube side inlet is connected to the reactor via the reaction catalyst delivery pipe 6. A reaction slide valve 15 is installed on the reaction catalyst delivery pipe 6. Its tube side outlet is connected to the regenerator 1 via the reaction catalyst inlet 7. Its shell side inlet is connected to the regenerator 1 via the regenerated catalyst outlet 8. Its shell side outlet 9 is connected to the conveying cyclone separator 3 via a first branch pipe 91. A conveying inlet valve 18 is installed on the first branch pipe 91. The shell side of the heat exchanger 2 is also connected to the nitrogen source 10 via the fluidized nitrogen inlet 101.

[0041] It is understood in the art that, in addition to shell-and-tube heat exchangers, ceramic heat exchangers or plate heat exchangers can also be used for the heat exchanger 2 in this invention. In this invention, the tube side of the heat exchanger 2 can be selected from one or more of finned tubes, finned tubes, and bare tubes (all referring to the outer side of the tube wall), preferably finned tubes; the materials of all components inside the heat exchanger 2 that come into contact with the catalyst can be wear-resistant materials that are readily available in the prior art.

[0042] The regenerated catalyst outlet 8 is connected to the shell-side outlet 9 and the fluidizing nitrogen inlet 101 via the internal space of the shell side of the heat exchanger 2. Preferably, one or more axial baffles may be provided in the shell side of the heat exchanger 2 to facilitate full fluidization and heat exchange. The reaction catalyst delivery pipe 6 is connected to the reaction catalyst inlet 7 via the tube side within the heat exchanger 2.

[0043] The fluidizing nitrogen inlet 101 should be located in the shell-side space of the heat exchanger 2, and one or more nitrogen nozzles can be provided according to the fluidization and heat exchange requirements. In a preferred embodiment, the heat exchanger 2 is arranged longitudinally, and its lower shell-side is provided with a built-in multi-nozzle annular pipe. The fluidizing nitrogen inlet 101 is connected to the multi-nozzle annular pipe to facilitate better fluidization.

[0044] The inlet of the conveying cyclone separator 3 is connected to the shell-side outlet 9 via the first branch pipe 91, for gas-solid separation of the regenerated catalyst from the heat exchanger 2; the catalyst outlet of the conveying cyclone separator 3 is connected to the regenerated catalyst conveying pipe 11, and a regeneration slide valve 16 is provided on the regenerated catalyst conveying pipe 11; the nitrogen source 10 is connected to the regenerated catalyst conveying pipe 11 downstream of the regenerated slide valve 16 via a nitrogen inlet 102; it is understood in the art that "downstream" refers to the direction of material flow in the regenerated catalyst conveying pipe.

[0045] In this invention, the conveying cyclone separator 3 can be one or more of a single-stage cyclone separator or a multi-stage cyclone separator. It can be one or more of the above-mentioned cyclone separators in a single unit, multiple units in series or in parallel. It can have one or more of a particle collector, a buffer section or a catalyst storage tank attached or not attached to the lower outlet of the cyclone separator. In some embodiments, the conveying cyclone separator 3 can be selected as multiple cyclone separators connected in parallel and can be further equipped with a catalyst buffer section or storage tank.

[0046] In a preferred embodiment, the gas phase outlet 12 of the conveying cyclone separator 3 is connected to the cyclone separation unit so that the gas phase separated by the conveying cyclone separator 3 and the exhaust gas to be discharged from the regenerator 1 are sent to the cyclone separation unit for gas-solid separation; further, the interior of the regenerator 1 and the gas phase outlet 12 of the conveying cyclone separator 3 are connected to the first-stage cyclone separator 4 through the first-stage cyclone separator inlet 17.

[0047] In some embodiments, the shell-side outlet 9 of the heat exchanger 2 is also connected via a second branch pipe 92 to the regeneration catalyst delivery pipe 11 between the conveying cyclone separator 3 and the regeneration slide valve 16. A bypass valve 19 is installed on the second branch pipe 92. During shutdown, the regeneration catalyst, along with the fluidized nitrogen, enters the regeneration catalyst delivery pipe 11 from the second branch pipe 91 through the shell-side outlet 9 and eventually returns to the reactor. At this time, the bypass valve 19 is fully open, and the delivery inlet valve 18 is fully closed.

[0048] During operation, the reaction catalyst from the reaction catalyst delivery pipe 6 first exchanges heat with the regenerated catalyst in the heat exchanger 2, and then enters the regenerator 1 for regeneration. The regenerated catalyst obtained after regeneration enters the heat exchanger 2 from the regenerator 1, is atomized by nitrogen gas from the fluidizing nitrogen inlet 101 and exchanges heat with the reaction catalyst, and then enters the conveying cyclone separator 3 for gas-solid separation. The separated regenerated catalyst enters the regenerated catalyst delivery pipe 11 and is sent out after being atomized by nitrogen gas from the conveying nitrogen inlet 102.

[0049] Specifically, the cooled regenerated catalyst, along with fluidized nitrogen, enters the conveying cyclone separator 3 from the first branch pipe 91 through the shell-side outlet 9. At this time, the conveying inlet valve 18 is fully open, and the bypass valve 19 is closed. The regenerated catalyst is partially degassed in the conveying cyclone separator 3. The catalyst linear velocity can be 5 to 25 m / s, such as 8, 10, 15 or 20 m / s, preferably 12 to 22 m / s.

[0050] The separated gas phase enters the first-stage cyclone separator 4 from the upper part of the conveying cyclone separator 3 through the gas phase outlet 12 and the first-stage cyclone separator inlet 17. After recovering catalyst particles with a diameter of 5μm or larger in the first and second-stage cyclone separators, it enters the subsequent process through the outlet 14 of the second-stage cyclone separator. The separated solid catalyst is finally sent back to the reactor from the lower part of the conveying cyclone separator 3 through the regenerated catalyst conveying pipe 11. During this process, the conveying density of the regenerated catalyst in the regenerated catalyst conveying pipe 11 (i.e., the density of the overall material conveyed by the conveying pipe) is 100-400 kg / m³. 3 The preferred value is 150–350 kg / m³. 3 .

[0051] In this invention, the regenerator 1 is a continuous circulating fluidized bed regenerator; in some embodiments, the diameter of the incoming reaction catalyst can be 1-500 μm, preferably 5-150 μm; the regeneration temperature is 550-750℃, preferably 630-690℃; the regeneration pressure is 0.03-0.18 MPa, preferably 0.05-0.1 MPa; the "reaction-regeneration" process is completed between the reactor and the regenerator in a continuous circulating fluidized bed manner.

[0052] In some embodiments, the amount of nitrogen introduced into the shell side of the heat exchanger 2 through the fluidized nitrogen inlet 101 can be 50–1000 Nm³. 3 / h, preferably 80~400Nm 3 / h, enters the heat exchanger 2, and is back-mixed and fluidized with the regenerated catalyst that enters the shell side of the heat exchanger 2 through the regenerated catalyst outlet 8. This promotes sufficient heat exchange between the regenerated catalyst and the reaction catalyst that enters the heat exchanger 2 through the reaction catalyst delivery pipe 6, achieving temperature equilibrium. This ensures that the regenerated catalyst sent to the subsequent process through the shell side outlet 9 does not impact the reaction environment, while avoiding reducing the thermal fluidity of the regenerated catalyst in the shell side of the heat exchanger 2 and at the shell side outlet 9.

[0053] In some embodiments, the inlet valve 18 and the regeneration slide valve 16 can be configured for cascade automatic control. A density meter can also be installed on the first branch pipe 91 downstream of the inlet valve 18 to automatically control the valve opening based on density changes, thereby controlling the catalyst flow rate and delivery density. Preferably, when the delivery density of the regenerated catalyst in the first branch pipe 91 is between 150 and 350 kg / m³... 3 When the flow rate varies within a certain range, the opening degree of the regeneration slide valve 16 and the delivery inlet valve 18 is automatically controlled inversely between 95% and 5% to control the flow rate and delivery density of the regenerated catalyst. That is, when the delivery density is 150 kg / m³, the flow rate is controlled accordingly. 3 Control the opening degree to 95% when the conveying density is 350 kg / m³ 3 The opening is controlled at 5%, and adjusted continuously and evenly in proportion during the period.

[0054] Those skilled in the art will understand that since the reaction catalyst delivery pipe 6, the reaction catalyst inlet 7, the regenerated catalyst outlet 8, the shell-side outlet 9, the branch pipe 91, the second branch pipe 92, and the regenerated catalyst delivery pipe 11 are all catalyst pipelines, when their delivery direction changes, the corresponding pipelines should adopt smooth elbow pipelines; preferably, the bending radius of the elbow pipeline should be as large as possible.

[0055] The present invention will be further illustrated below with reference to embodiments / comparative examples.

[0056] Example

[0057] For example, a methanol-to-olefins (MTO) unit of a certain scale with an annual processing capacity of 1.8 million tons of methanol and an operating load of 80-110% would be equipped with such a unit. Figure 1 The system shown is an example:

[0058] The device employs a continuous reaction-regeneration method. The regeneration pressure of regenerator 1 is 0.06–0.085 MPa, and the regeneration temperature is 640–670 °C. The internal space of regenerator 1 is equipped with multiple sets of series-connected primary cyclone separators 4 and secondary cyclone separators 5 to recover the catalyst from the regenerated flue gas. The recovered catalyst, along with the catalyst in the regenerator bed, enters the shell side of heat exchanger 2 through regenerated catalyst outlet 8, where it is reacted with 100–300 Nm³ of nitrogen from nitrogen source 10 via fluidized nitrogen inlet 101. 3 The nitrogen gas is thoroughly backmixed and heats the catalyst from the reactor, which enters the tube side of the heat exchanger 2 via the catalyst delivery pipe 6. This reduces the volume and pressure of the gas phase components at the regenerated catalyst outlet 8, initially reducing gas resistance during the regenerated catalyst delivery process. The nitrogen gas is then delivered to the first branch pipe 91 via the shell-side outlet 9 and enters the delivery cyclone separator 3 for gas-solid separation (degassing). The delivered nitrogen gas increases the linear velocity of the catalyst in the delivery cyclone separator 3 to 14-20 m / s. Some of the flue gas that has not been completely de-catalyzed (where the catalyst diameter is <20 μm) enters the inlet 17 of the first-stage cyclone separator from the gas phase outlet 12 at the top of the delivery cyclone separator 3, where it participates again in the recovery and regeneration of the catalyst in the regenerator. After being heat-exchanged at the heat exchanger 2 via the regenerated catalyst outlet 8, the regenerated catalyst is separated by the delivery cyclone separator 3. 95% of the regenerated catalyst enters the regenerated catalyst delivery pipe 11 from the bottom of the delivery cyclone separator 3 and is then transported back to the reactor by nitrogen from the nitrogen source 10 via the nitrogen delivery inlet 102. The aforementioned reaction catalyst enters the regenerator 1 from the reaction catalyst inlet 7, completing the entire circulation fluidization and transport process of the catalyst.

[0059] During normal production, a density meter is installed on the first branch pipe 91 after the inlet valve 18 to measure the density of the catalyst being transported, which is between 150 and 350 kg / m³. 3 When the flow rate varies within a certain range, the opening degree of the regeneration slide valve 16 and the delivery inlet valve 18 is automatically controlled inversely between 95% and 5% to control the catalyst flow rate and delivery density.

[0060] Comparative Example

[0061] Taking a typical methanol-to-olefins regeneration and regeneration catalyst delivery system as an example (see...) Figure 2In this comparative example, the conventional regenerator 1' (which has the same cyclone separation unit as in the embodiment) is equipped with a catalyst delivery inlet 7' and a regenerated catalyst delivery outlet 6'. Each inlet and outlet is equipped with a regeneration slide valve 8' and a waiting slide valve 9'. From the nitrogen source 5' to the two slide valves, there are outlet-feeding loose nitrogen 51' and inlet-feeding loose nitrogen 52' to loosen the catalyst during the delivery process. In this comparative example, the temperature of the regenerated catalyst is often above 650°C. Before the latent heat is recovered, it is delivered to the reactor, resulting in a local temperature in the reactor exceeding the optimal product distribution temperature, which easily leads to side reactions and reduces the reaction yield. Furthermore, based on long-term actual operation of plants using this type of delivery method, the large variation in catalyst delivery density in this comparative example easily leads to catalyst bridging, blockage, and other delivery problems, resulting in poor circulation fluidization of the reaction regeneration system and reduced production efficiency.

[0062] Under the condition that other production conditions remain unchanged, comparing the above examples with the comparative examples, when the product consumption in the comparative examples is 2.95 to 3.00 t / t (tons of product / tons of raw materials), the product consumption in the examples is 2.92 to 2.97 t / t (tons of product / tons of raw materials) because the reaction-regeneration system is more uniformly fluidized, the catalyst carbon set rate range is narrower, and the selectivity of the target product is increased. Compared with the comparative examples, the product consumption in the examples is reduced by 1%.

[0063] Meanwhile, because the embodiments reduced the occurrence of catalyst delivery obstruction and lowered the catalyst operating temperature difference, thereby reducing catalyst loss, under the condition that other production conditions remain unchanged, compared with the comparative example catalyst consumption of 0.8-0.9 kg / t (kg catalyst / ton of product), the catalyst consumption of the embodiments is 0.75-0.81 kg / t (kg catalyst / ton of product), which is a reduction of 6-10%.

Claims

1. A system for delivering a regenerated catalyst, comprising: The regenerator (1) is connected to the reaction catalyst inlet (7) and the regenerated catalyst outlet (8) and is used to regenerate the reaction catalyst from the reactor; the reaction catalyst inlet (7) is used to deliver the reaction catalyst into the regenerator and the regenerated catalyst outlet (8) is used to deliver the regenerated catalyst out of the regenerator (1). A heat exchanger (2) is used to balance the temperature of the reaction catalyst and the regenerated catalyst. The heat exchanger (2) includes a tube side and a shell side. Its tube side inlet is connected to the reactor via a reaction catalyst delivery pipe (6). A reaction slide valve (15) is provided on the reaction catalyst delivery pipe (6). Its tube side outlet is connected to the regenerator (1) via the reaction catalyst inlet (7). Its shell side inlet is connected to the regenerator (1) via the regenerated catalyst outlet (8). Its shell side outlet (9) is connected to the conveying cyclone separator (3) via a first branch pipe (91). A conveying inlet valve (18) is provided on the first branch pipe (91). The shell side of the heat exchanger (2) is also connected to the nitrogen source (10) via a fluidized nitrogen inlet (101). Cyclone separation unit, which is located in the regenerator (1), is used to remove catalyst particles entrained in the regenerated flue gas of the regenerator (1) and send them back to the regenerator (1). A conveying cyclone separator (3) is provided, the inlet of which is connected to the shell-side outlet (9) via the first branch pipe (91) for gas-solid separation of the regenerated catalyst from the heat exchanger (2); the catalyst outlet of the conveying cyclone separator (3) is connected to the regenerated catalyst conveying pipe (11), a regeneration slide valve (16) is provided on the regenerated catalyst conveying pipe (11), and the nitrogen source (10) is connected to the regenerated catalyst conveying pipe (11) downstream of the regenerated slide valve (16) via a nitrogen inlet (102); A cascade automatic control is set between the regeneration slide valve (16) and the delivery inlet valve (18), and a density meter is set on the first branch pipe (91) after the delivery inlet valve (18).

2. The system according to claim 1, characterized in that, The gas phase outlet (12) of the conveying cyclone separator (3) is connected to the cyclone separation unit so that the gas phase separated by the conveying cyclone separator (3) and the regenerated flue gas of the regenerator (1) are sent together into the cyclone separation unit for gas-solid separation.

3. The system according to claim 1, characterized in that, The cyclone separation unit includes a primary cyclone separator (4) and a secondary cyclone separator (5); wherein the primary cyclone separator (4) is connected to the interior of the regenerator (1) and the gas phase outlet (12) of the conveying cyclone separator (3) via the primary cyclone separator inlet (17), and the gas phase outlet of the primary cyclone separator (4) is connected to the secondary cyclone separator (5) via the secondary cyclone separator inlet (13).

4. The system according to claim 1, characterized in that, The shell-side outlet (9) of the heat exchanger (2) is also connected to the regeneration catalyst delivery pipe (11) between the conveying cyclone separator (3) and the regeneration slide valve (16) via a second branch pipe (92), and a bypass valve (19) is provided on the second branch pipe (92).

5. The system according to any one of claims 1-4, characterized in that, The heat exchanger (2) is arranged longitudinally, and its shell side is provided with a built-in multi-nozzle ring pipe. The fluidized nitrogen inlet (101) is connected to the multi-nozzle ring pipe.

6. The system according to claim 5, characterized in that, The shell side is also provided with one or more radial baffles, and the multi-nozzle annular tube is disposed at the connection between the baffle and the shell side wall.

7. A method for delivering a regenerated catalyst using the system of any one of claims 1-6, the method comprising: The reaction catalyst from the reaction catalyst delivery pipe (6) first exchanges heat with the regenerated catalyst in the heat exchanger (2) and then enters the regenerator (1) for regeneration. The regenerated catalyst obtained after regeneration enters the heat exchanger (2) from the regenerator (1), is circulated by nitrogen gas from the fluidized nitrogen inlet (101) and exchanges heat with the reaction catalyst, and then enters the conveying cyclone separator (3) for gas-solid separation. The separated regenerated catalyst enters the regenerated catalyst delivery pipe (11), is circulated by nitrogen gas from the conveying nitrogen inlet (102) and then sent out.

8. The method according to claim 7, characterized in that, The method further includes: the gas phase separated from the conveying cyclone separator (3) and the regenerated flue gas from the regenerator (1) are fed together into the cyclone separation unit for gas-solid separation, so as to remove the catalyst particles entrained therein and send them back to the regenerator (1).

9. The method according to claim 7, characterized in that, The regenerator (1) is a continuous circulating fluidized bed regenerator; the diameter of the reaction catalyst is 1-500 μm; the regeneration temperature is 550-750℃; and the regeneration pressure is 0.03-0.18 MPa. The amount of nitrogen gas introduced into the shell side of the heat exchanger (2) through the fluidized nitrogen gas inlet (101) is 50-1000 Nm 3 / h; The linear velocity of the regenerated catalyst entering the conveying cyclone separator (3) is 5-25 m / s; The separated regenerated catalyst is sent from the lower part of the transport cyclone (3) to the reactor through the regenerated catalyst transport pipe (11), and the transport density of the regenerated catalyst in the regenerated catalyst transport pipe (11) is 100-400 kg / m 3 .

10. The method according to claim 9, characterized in that, The reaction catalyst has a diameter of 5–150 μm; the regeneration temperature is 630–690 °C; and the regeneration pressure is 0.05–0.1 MPa.

11. The method according to claim 9, characterized in that, The amount of nitrogen introduced into the shell side of the heat exchanger (2) through the fluidized nitrogen inlet (101) is 80-400 Nm³. 3 / h.

12. The method according to claim 9, characterized in that, The linear velocity of the regenerated catalyst entering the conveying cyclone separator (3) is 12-22 m / s.

13. The method according to claim 9, characterized in that, The separated regenerated catalyst is fed from the lower part of the conveying cyclone separator (3) to the reactor through the regenerated catalyst conveying pipe (11). During this process, the conveying density of the regenerated catalyst in the regenerated catalyst conveying pipe (11) is 150-350 kg / m³. 3 .

14. The method according to any one of claims 7-13, characterized in that, When the transport density of the regenerated catalyst in the first branch pipe (91) is 150-350 kg / m³ 3 When the flow rate changes within the specified range, the opening degree of the regeneration slide valve (16) and the delivery inlet valve (18) is automatically controlled inversely between 95% and 5% to control the flow rate and delivery density of the regeneration catalyst.

15. The method according to claim 14, characterized in that, In the shutdown condition, close the inlet valve (18) and open the bypass valve (19) so that the regenerated catalyst enters the regenerated catalyst delivery pipe (11) through the second branch pipe (92) after leaving the shell side of the heat exchanger (2) and finally returns to the reactor until the reactor and regenerator discharge all the catalyst.

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