Fischer-Tropsch synthesis catalyst gas-solid phase continuous activation system, method and application

Abstract

The present invention relates to the field of Fischer-Tropsch synthesis catalysts, and in particular to a gas-solid phase continuous activation system for Fischer-Tropsch synthesis catalysts, comprising: a main reactor and at least two auxiliary reactors in parallel; wherein the auxiliary reactors are used to perform temperature activation on an unactivated catalyst to obtain an intermediate catalyst; the main reactor is used to perform constant temperature activation on the intermediate catalyst to obtain an activated catalyst; wherein the main reactor is connected to only one of the auxiliary reactors at a time, and when connected, the main reactor has completed the constant temperature activation of the previous intermediate catalyst and inputs the next intermediate catalyst into the main reactor to continuously perform the next constant temperature activation; wherein the previous intermediate catalyst and the next intermediate catalyst come from different auxiliary reactors. The system can realize uninterrupted and continuous activation of the Fischer-Tropsch synthesis catalyst, significantly shorten the activation cycle, improve the activation effect, and reduce catalyst wear during the activation process.

Description

Technical Field

[0001] The present invention relates to the field of Fischer-Tropsch synthesis catalysts, and in particular to a gas-solid phase continuous activation system, method and application of Fischer-Tropsch synthesis catalysts. Background Art

[0002] The Fischer-Tropsch synthesis reaction is a core step in the indirect coal liquefaction process. It involves the synthesis of hydrocarbon liquid fuels from synthesis gas (H2 + CO) in the presence of a catalyst at a certain temperature and pressure. In industry, the Fischer-Tropsch synthesis reaction is typically carried out in a slurry bed reactor with a three-phase gas-liquid-solid system, where the solid phase is a catalyst, including iron-based and cobalt-based catalysts. Fischer-Tropsch synthesis catalysts are in an oxidized state upon leaving the factory and lack catalytic activity. They require activation treatment with hydrogen, carbon monoxide, or a mixture of the two to form a stable active phase and achieve catalytic performance.

[0003] The current activation process of gas-solid fluidized bed Fischer-Tropsch catalysts is performed in batches intermittently, making it impossible to achieve continuous activation operation of the reactor. The main reason is that the activation reaction of fresh catalyst requires a heating process of more than 10 hours. Since the activation reaction is generally carried out in a separate reactor, the catalyst undergoes a heating process after entering the reactor. After activation is completed and the catalyst is unloaded, the reactor must undergo a cooling process to receive the next batch of catalyst. Therefore, after each batch of catalyst is activated, the heating process will cause insufficient reactor utilization, and the cooling process will cause the reactor to be idle and waiting for cooling. Therefore, it is impossible to achieve seamless continuous activation between batches of catalysts. In addition, the gas flow rate must be adjusted during the heating and cooling processes, which increases the complexity of the operation and may cause reaction instability.

[0004] CN103551207A discloses a fixed fluidized bed or gas-solid bubbling bed Fischer-Tropsch catalyst reduction activation system, comprising: at least one fixed fluidized bed reactor or gas-solid bubbling bed reactor in which the Fischer-Tropsch catalyst is reduced and activated; and at least one cyclone separator for separating fine particles and / or dust of the Fischer-Tropsch catalyst and tail gas generated by the reduction and activation from the reduced and activated Fischer-Tropsch catalyst. The activation process of this system is an intermittent operation carried out in batches, and a continuous operation method is not mentioned.

[0005] CN106669857A discloses a method for activating a precipitated iron Fischer-Tropsch catalyst, which comprises: transporting the precipitated iron Fischer-Tropsch catalyst to be activated to an activation reactor in the form of a fluidized bed through an inert carrier gas, and contacting and reducing it with a reducing gas under reducing conditions. This method uses an independent gas-solid fluidized bed reactor, but the pressure of the reduction reaction is in the range of 0.1-0.5 MPa. In actual industrial applications, low pressure is not conducive to high-quality activation. This method also does not provide a heating rate curve for the heating process and a device operation process for the heating stage. At the same time, its activation process is still an intermittent operation carried out in batches, and no method for continuous operation is mentioned.

[0006] CN111450780A discloses a fluidized bed activation reaction system comprising a storage tank, a fluidized bed activation reactor, a gas separator, and a gas compressor. The effectiveness of this system relies on the specific structure of the fluidized bed activation reactor. Furthermore, the activation process is performed intermittently in batches, with no mention of continuous operation.

[0007] CN107149948A discloses a reduction method for a Fischer-Tropsch synthesis iron-based catalyst, wherein the reduction reaction pressure used in the method is in the range of 0.5-2 MPa, which is low for the overall pressure of a gas-solid fluidized bed; the superficial gas velocity of the reducing gas is 0.04-0.12 m / s, which is within the range of a bubbling fluidized bed, has a low flow rate, and has poor mass transfer and heat transfer effects. In this method, the entire reaction process of the catalyst from room temperature to a final temperature of 260-280°C is carried out in stages according to a temperature gradient, but the total reaction time is relatively long, and the total constant temperature reaction time of each temperature stage alone requires at least 10 hours. At the same time, the activation process is still an intermittent operation carried out in batches, and no continuous operation method is mentioned.

[0008] Therefore, there is an urgent need to develop a system and method that can achieve continuous gas-solid phase activation of Fischer-Tropsch synthesis catalysts to improve the efficiency and stability of the activation reaction, shorten the reaction cycle, and obtain catalyst products with better performance. Summary of the Invention

[0009] The purpose of the present invention is to overcome the problems of the prior art in the activation of Fischer-Tropsch synthesis catalysts, such as long reaction cycle, unsatisfactory activation efficiency, poor reaction process stability and large catalyst wear, and to provide a gas-solid phase continuous activation system, method and application of Fischer-Tropsch synthesis catalysts.

[0010] In order to achieve the above-mentioned object, the first aspect of the present invention provides a gas-solid phase continuous activation system for Fischer-Tropsch synthesis catalyst, comprising: a main reactor and at least two auxiliary reactors connected in parallel; wherein,

[0011] The auxiliary reactor is used to activate the unactivated catalyst by increasing the temperature to obtain an intermediate catalyst;

[0012] The main reactor is used to activate the intermediate catalyst at a constant temperature to obtain an activated catalyst;

[0013] The main reactor is connected to only one auxiliary reactor at a time, and when connected, the main reactor has completed the constant temperature activation of the previous intermediate catalyst, and the next intermediate catalyst is input into the main reactor to continue the next constant temperature activation;

[0014] Wherein, the first stream of intermediate catalyst and the second stream of intermediate catalyst come from different auxiliary reactors.

[0015] A second aspect of the present invention provides a method for gas-solid phase continuous activation of a Fischer-Tropsch synthesis catalyst, comprising:

[0016] activating multiple strands of inactivated catalyst by increasing the temperature to obtain multiple strands of intermediate catalyst, and then continuously activating the multiple strands of intermediate catalyst by constant temperature in succession to obtain activated catalyst;

[0017] The process of the constant temperature activation includes the following steps: when the first stream of the intermediate catalyst completes the first constant temperature activation, the second stream of the intermediate catalyst begins the second constant temperature activation.

[0018] The third aspect of the present invention provides the application of the system described in the first aspect and the method described in the second aspect in a Fischer-Tropsch synthesis reaction.

[0019] Through the above technical solution, the present invention has the following beneficial effects:

[0020] (1) The constant temperature activation and temperature activation of the Fischer-Tropsch synthesis catalyst are distributed in different reactors, and the main reactor used for the constant temperature activation is used as the core equipment in the activation process, which can ensure that the reaction pressure, temperature and superficial gas velocity of the activation are constant, and solve the problem of insufficient reactor utilization or even vacancy during the heating and cooling processes in the existing use of a single reactor for activation. Therefore, the main reactor can continuously carry out the activation reaction without interruption, and the activation of the catalyst between batches is seamlessly connected, which significantly shortens the reaction cycle and improves the activation effect;

[0021] (2) The operation in the main reactor is only catalyst transfer, and the reaction process does not require adjustment of temperature, pressure and gas volume, which greatly improves the stability of the reaction process; the temperature rise activation and cooling processes are set to be carried out in the bubbling fluidized bed reactor, which can reduce the loss of non-main reaction processes and reduce the wear of the catalyst during the temperature rise activation reaction;

[0022] (3) The constant temperature activation in the main reactor adopts a high-pressure turbulent fluidized bed reaction process, which can shorten the reaction time of constant temperature activation to 1-6 hours;

[0023] (4) The continuous activation operation can provide activated catalysts to the subsequent Fischer-Tropsch synthesis unit at any time, thereby reducing the single replacement amount of the Fischer-Tropsch synthesis unit, ensuring the stable operation of the Fischer-Tropsch synthesis reactor, and even providing conditions for realizing the continuous replacement operation of the Fischer-Tropsch synthesis unit;

[0024] (5) The improvement of activation effect can reduce the volume and scale of activation reactor and related process equipment, which can significantly reduce the investment cost of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0026] Figure 1 It is a schematic diagram of a gas-solid phase continuous activation system for a Fischer-Tropsch synthesis catalyst according to one embodiment of the present invention.

[0027] Description of Reference Numerals

[0028] 1-Feeding tank 2-Auxiliary reactor 3-Auxiliary reactor

[0029] 4- Main reactor 5- Gas-solid separation device 6- First heat exchanger

[0030] 7-Oil washing tower 8-Gas compression device 9-Second heat exchanger DETAILED DESCRIPTION

[0031] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0032] The following is a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0033] The first aspect of the present invention provides a gas-solid phase continuous activation system for a Fischer-Tropsch synthesis catalyst, comprising: a main reactor and at least two auxiliary reactors connected in parallel; wherein,

[0034] The auxiliary reactor is used to activate the unactivated catalyst by increasing the temperature to obtain an intermediate catalyst;

[0035] The main reactor is used to activate the intermediate catalyst at a constant temperature to obtain an activated catalyst;

[0036] The main reactor is connected to only one auxiliary reactor at a time, and when connected, the main reactor has completed the constant temperature activation of the previous intermediate catalyst, and the next intermediate catalyst is input into the main reactor to continue the next constant temperature activation;

[0037] Wherein, the first stream of intermediate catalyst and the second stream of intermediate catalyst come from different auxiliary reactors.

[0038] The present invention adopts a method of separating the temperature-raising activation stage and the constant temperature activation stage in the catalyst activation process into different reactors, wherein the number of the main reactor is one and the number of the auxiliary reactors is not less than two, so as to meet the requirement of inputting the intermediate catalyst material into the main reactor in a coordinated manner, thereby realizing the continuous constant temperature activation of multiple streams of the intermediate catalyst in the main reactor.

[0039] According to the present invention, the auxiliary reactors are independent of each other and are connected to the main reactor in a parallel manner. Different auxiliary reactors are started at intervals to perform the temperature-raising activation. Specifically, the first auxiliary reactor is fed with a first strand of unactivated catalyst and subjected to temperature-raising activation (this operation is defined as the previous temperature-raising activation), and based on the start-up time of the previous temperature-raising activation, after a certain time interval, the second auxiliary reactor is fed with a second strand of unactivated catalyst and subjected to the next temperature-raising activation. By analogy, different auxiliary reactors successively carry out the above process to achieve temperature-raising activation of multiple strands of the unactivated catalyst to obtain multiple strands of the intermediate catalyst.

[0040] According to the present invention, different auxiliary reactors take turns to cooperate in conveying the intermediate catalyst material to the main reactor. Specifically, the first auxiliary reactor completes the temperature activation while being connected to the main reactor and conveying the intermediate catalyst to the main reactor. The connection between the two is immediately disconnected after the delivery is completed. The intermediate catalyst from the first auxiliary reactor is subjected to constant temperature activation in the main reactor (this operation is defined as the previous constant temperature activation). At the same time, the first auxiliary reactor after unloading continues to feed a new stream of unactivated catalyst after the cooling process and performs temperature activation on it. The previous constant temperature activation is completed and the activated catalyst obtained is removed from the main reactor. At the same time, the second auxiliary reactor has completed the temperature activation and is connected to the main reactor, conveying the intermediate catalyst to the main reactor to take over the next constant temperature activation. By analogy, different auxiliary reactors take turns to carry out the above process, so as to realize the continuous constant temperature activation of multiple streams of the intermediate catalyst to obtain activated catalysts.

[0041] In the present invention, the main reactor serves as the core equipment in the activation process flow, and its operations are only the feeding of intermediate catalyst, constant temperature activation and discharge of activated catalyst. The cooling process before taking over the next batch of catalyst after the temperature increase activation and the constant temperature activation is completed is carried out in the auxiliary reactor, thereby effectively solving the problem of insufficient reactor utilization or even vacancy during the temperature increase and temperature decrease processes when using a single reactor for activation, which can greatly shorten the reaction cycle of catalyst activation and improve the activation efficiency and catalyst performance.

[0042] According to the present invention, the two or more auxiliary reactors are of the same type, preferably a bubbling fluidized bed reactor, which can effectively reduce the wear of the catalyst during the activation process; more preferably, the two or more auxiliary reactors have the same specifications and sizes.

[0043] According to the present invention, the main reactor is preferably a turbulent fluidized bed reactor, and the reaction time of the constant temperature activation can be further shortened by a high-pressure turbulent fluidized bed reaction process.

[0044] According to the present invention, the gas-solid phase continuous activation system for Fischer-Tropsch synthesis catalysts further comprises a feeding tank for heating the unactivated catalyst and feeding it in batches to the auxiliary reactor. The feeding tank is equipped with a heating coil. After the unactivated catalyst is fed into the feeding tank, it is heated to the starting temperature of the temperature-raising activation and fed to different auxiliary reactors in the order in which the temperature-raising activation is subsequently started.

[0045] According to the present invention, the gas-solid phase continuous activation system for Fischer-Tropsch synthesis catalyst further comprises a gas-solid separation device, a first heat exchanger, a second heat exchanger, an oil washing tower and a gas compression device; wherein,

[0046] The gas-solid separation device is connected to the main reactor and is used to remove dust from the reaction tail gas discharged from the main reactor, remove fine catalyst particles and / or dust therein, and obtain dust-removed reaction tail gas;

[0047] The first heat exchanger is used to perform heat exchange between the reaction tail gas after dust removal and the reducing gas required for activation;

[0048] The second heat exchanger is connected to the auxiliary reactor and is used to perform heat exchange between the reaction tail gas discharged from the auxiliary reactor and the reducing gas required for activation;

[0049] The oil washing tower is connected to the first heat exchanger, the second heat exchanger and the gas compression device respectively, and is used to further wash and remove the catalyst fine particles and / or dust entrained in the reaction tail gas after heat exchange, and divide the washed gas into two streams, one as circulating gas and the other as purge gas;

[0050] The gas compression device is used to increase the pressure of the circulating gas, and then mix it with fresh synthesis gas to form reducing gas, which continues to circulate and participate in the temperature-raising activation and constant temperature activation.

[0051] In the present invention, the gas-solid separation device may be a conventional device in the art for separating fine particles and / or dust from gas, and preferably a cyclone separator.

[0052] In the present invention, the first heat exchanger and the second heat exchanger can be conventional heat exchange equipment in the art, and this application has no special limitation on them.

[0053] In the present invention, there is no particular limitation on the gas compression device, and conventional options in the art, such as a compressor, may be used.

[0054] According to the present invention, preferably, the Fischer-Tropsch synthesis catalyst gas-solid phase continuous activation system may further include a heater for further heating the reducing gas exiting the first heat exchanger and the second heat exchanger so that its temperature meets the requirements of the activation reaction.

[0055] A second aspect of the present invention provides a method for gas-solid phase continuous activation of a Fischer-Tropsch synthesis catalyst, comprising:

[0056] activating multiple strands of inactivated catalyst by increasing the temperature to obtain multiple strands of intermediate catalyst, and then continuously activating the multiple strands of intermediate catalyst by constant temperature in succession to obtain activated catalyst;

[0057] The process of the constant temperature activation includes the following steps: when the first stream of the intermediate catalyst completes the first constant temperature activation, the second stream of the intermediate catalyst begins the second constant temperature activation.

[0058] According to the present invention, the unactivated catalyst is an iron-based catalyst or a cobalt-based catalyst for Fischer-Tropsch synthesis, wherein the active component is in an oxidized state. Preferably, the unactivated catalyst has an average particle size of 70-80 μm, which falls within the Geldart A particle range in the field of gas-solid fluidization and exhibits excellent gas-solid fluidization properties.

[0059] According to the present invention, in order to realize continuous activation, shorten the activation cycle and improve the utilization rate of the activation reactor, preferably, the interval between the unactivated catalysts of multiple strands is started to carry out the temperature-raising activation. The specific process can be that the first strand of unactivated catalyst is subjected to temperature-raising activation (this operation is defined as the previous temperature-raising activation), and with the starting moment of the previous temperature-raising activation as a benchmark, after a certain time interval, the second strand of unactivated catalyst is subjected to the next temperature-raising activation. By analogy, the unactivated catalysts of multiple strands successively carry out the above process to obtain the intermediate catalysts of multiple strands. The time interval between the starting time of the previous temperature-raising activation and the next temperature-raising activation satisfies the intermediate catalysts of multiple strands to realize the continuous constant temperature activation by taking over, which can be determined according to the specific temperature-raising activation time and the constant temperature activation time.

[0060] According to a preferred embodiment of the present invention, during the constant temperature activation process, while the first stream of intermediate catalyst completes the previous constant temperature activation, the second stream of intermediate catalyst is just completed and starts to take over the next constant temperature activation.

[0061] According to the present invention, the temperature-raising activation is carried out under bubbling fluidization (in the present invention, the bubbling fluidization refers to the flow state of the gas-solid two-phase system in the bubbling fluidized bed reactor), and the conditions for the temperature-raising activation may include: a pressure of 1.5-7 MPa, preferably 2.5-5 MPa; an apparent gas velocity of the reducing gas of 0.06-0.1 m / s, preferably 0.06-0.08 m / s; a heating rate of 10-40°C / h, preferably 20-30°C / h.

[0062] According to the present invention, preferably, before the temperature-raising activation, the temperature of the plurality of strands of the unactivated catalyst is heated to 160-180° C., which is the same as the starting temperature of the temperature-raising activation.

[0063] According to the present invention, the constant temperature activation is carried out under turbulent fluidization (in the present invention, the turbulent fluidization refers to the flow state of the gas-solid two-phase system in the turbulent fluidized bed reactor). The conditions for the constant temperature activation may include: a pressure of 1-6 MPa, preferably 2-4 MPa; an apparent gas velocity of the reducing gas of 0.3-0.9 m / s, preferably 0.4-0.7 m / s; a temperature of 240-450°C, preferably 260-350°C; and a time of 1-6 hours, preferably 3-4 hours. The present invention adopts a high-pressure turbulent fluidized bed reaction process, which can shorten the reaction time of the constant temperature activation and thus significantly shorten the cycle of the entire activation process.

[0064] In the present invention, preferably, the pressure of the temperature-raising activation is 0.5-1 MPa higher than the pressure of the constant temperature activation, which is beneficial to the catalyst transfer operation.

[0065] In the present invention, the temperature to which the temperature-raising activation finally reaches is the same as the temperature of the constant-temperature activation.

[0066] According to the present invention, the gas-solid phase continuous activation method of the Fischer-Tropsch synthesis catalyst further comprises:

[0067] Heat exchange is performed between the reaction tail gas activated by heating and the reducing gas required for activation;

[0068] The reaction tail gas activated at constant temperature is dedusted, and the dedusted reaction tail gas is heat exchanged with the reducing gas required for activation;

[0069] The reaction tail gas after the above heat exchange is oil washed to further remove the fine catalyst particles and / or dust entrained therein, and the washed gas is divided into two streams, one of which is released as purge gas, and the other is mixed with fresh synthesis gas as circulating gas to become reducing gas, which continues to circulate and participate in the above temperature-raising activation and constant temperature activation.

[0070] In the present invention, the synthesis gas is a mixed gas containing CO and hydrogen produced by coal gasification, and is a conventional gas used for reduction activation of Fischer-Tropsch synthesis catalysts.

[0071] In the present invention, the dust removal is used to remove the catalyst fine particles and / or dust in the constant temperature activated reaction tail gas to obtain the dust-removed reaction tail gas.

[0072] In the present invention, the washing liquid used in the oil washing can be selected from conventional ones in the art, for example, heavy diesel oil, liquid wax, etc.

[0073] In the present invention, the quantity ratio of the purge gas to the recycle gas can be flexibly adjusted according to the needs of the activation reaction, and the present invention does not impose any limitation thereto.

[0074] The third aspect of the present invention provides the application of the system described in the first aspect and the method described in the second aspect in a Fischer-Tropsch synthesis reaction.

[0075] According to the present invention, the activation of the Fischer-Tropsch synthesis catalyst by the system and method of the present invention can significantly improve the performance of the activated catalyst, increase the conversion rate of the Fischer-Tropsch synthesis reaction, extend the service life of the catalyst, and reduce the amount of catalyst used. At the same time, it can reduce the blockage of the wax filter element in the Fischer-Tropsch synthesis device, reduce the frequency of shutdowns and maintenance, and improve the overall economic benefits of the device.

[0076] The following combination Figure 1 , further illustrating the application process of the activation method provided by the present invention in the gas-solid phase continuous activation system of the Fischer-Tropsch synthesis catalyst of the present invention. Figure 1 The system shown in the figure includes two auxiliary reactors and one main reactor. The specific working process is as follows:

[0077] The synthesis gas is introduced into the entire system including the auxiliary reactor 2, the auxiliary reactor 3 and the main reactor 4 to achieve normal operation of the synthesis gas in the system;

[0078] An unactivated catalyst is loaded into a feeding tank 1 and heated to a temperature of 160-180°C; then, one stream of the unactivated catalyst is fed into the auxiliary reactor 2 and subjected to temperature activation under conditions including a pressure of 1.5-7 MPa, a superficial velocity of the reducing gas of 0.06-0.1 m / s, and a heating rate of 10-40°C / h; when the temperature reaches 240-450°C required for constant temperature activation, the temperature activation is completed, and the auxiliary reactor 2 is connected to the main reactor 4 and the prepared intermediate catalyst is transported to the main reactor 4. The connection between the two is immediately disconnected after the transport is completed;

[0079] According to the temperature rise activation time of the auxiliary reactor 2 and the constant temperature activation time of the main reactor 4, the start-up time interval of the auxiliary reactor 3 and the auxiliary reactor 2 is determined, and according to this time interval, another stream of unactivated catalyst in the feeding tank 1 is fed into the auxiliary reactor 3, and the temperature rise activation is carried out under the same reaction conditions as above, and the temperature is raised to the same target temperature; the temperature rise activation pressure of the auxiliary reactor 2 and the auxiliary reactor 3 is 0.5-1MPa higher than the constant temperature activation pressure of the main reactor 4;

[0080] The intermediate catalyst from the auxiliary reactor 2 enters the main reactor 4 and is activated at a constant temperature for 1-6 hours under the conditions of a pressure of 1-6MPa, an apparent gas velocity of the reducing gas of 0.3-0.9m / s, and a temperature of 240-450°C. After the activation is completed, the activated catalyst is removed from the main reactor 4. At the same time, the auxiliary reactor 3 is heated to the temperature required for constant temperature activation and connected to the main reactor 4. The intermediate catalyst produced is transported to the main reactor 4 through a pressure difference to take over the next constant temperature activation. After unloading, the auxiliary reactor 2 and the auxiliary reactor 3 must first be cooled to 160-180°C, and then continue to receive a new stream of unactivated catalyst from the feeding tank 1 and perform temperature activation under the same reaction conditions as mentioned above. The auxiliary reactor 2 and the auxiliary reactor 3 repeat the above process, taking turns to input the required intermediate catalyst into the main reactor 4, so that the main reactor 4 can operate continuously without interruption, and the activated catalyst can be produced and continuously provided.

[0081] In the above process, the reaction tail gas discharged from the auxiliary reactor 2 and the auxiliary reactor 3 enters the second heat exchanger 9 for heat exchange with the reducing gas; the reaction tail gas discharged from the main reactor 4 first enters the gas-solid separation device 5 for dust removal, and then the reaction tail gas after dust removal enters the first heat exchanger 6 for heat exchange with the reducing gas; the reaction tail gas after the above heat exchange is combined and enters the oil washing tower 7, and is further washed to remove the fine catalyst particles and / or dust entrained therein. The washed gas is divided into two streams, one as circulating gas and the other as released purge gas; the circulating gas enters the gas compression device 8, and after being pressurized, it is mixed with fresh synthesis gas to become reducing gas, and is re-circulated into the system to participate in the activation process.

[0082] The present invention will be described in detail below by way of examples.

[0083] The unactivated catalyst is an iron-based catalyst for Fischer-Tropsch synthesis reaction (the weight ratio of the active material and the carrier in the catalyst is Fe2O3:Cu:K:SiO2=100:2:3:20), and the average particle size is 70-80 μm.

[0084] Example 1

[0085] use Figure 1 The Fischer-Tropsch synthesis catalyst gas-solid phase continuous activation system of the present invention is used to activate the catalyst.

[0086] The synthesis gas is introduced into the entire system, and the pressure of the auxiliary reactor 2 and the auxiliary reactor 3 is controlled to be 3.5 MPa, and the pressure of the main reactor 4 is controlled to be 3 MPa, so as to achieve normal operation of the synthesis gas in the system;

[0087] An unactivated catalyst was placed in the feeding tank 1 and heated to 180° C.; then, a 16 kg stream of the unactivated catalyst was fed into the auxiliary reactor 2 and subjected to temperature activation for 4 hours under the conditions of a pressure of 3.5 MPa, a superficial velocity of the reducing gas of 0.08 m / s, and a heating rate of 20° C. / h; when the temperature reached 260° C., the temperature activation was completed, and the auxiliary reactor 2 was connected to the main reactor 4, and the prepared intermediate catalyst was transported to the main reactor 4 by pressure difference, and the connection between the two was immediately disconnected after the transport was completed;

[0088] After the auxiliary reactor 2 was activated for 3 hours, another 16 kg of unactivated catalyst in the feed tank 1 was fed into the auxiliary reactor 3 and activated under the same reaction conditions as above, and the temperature was raised to the same target temperature of 260°C.

[0089] The intermediate catalyst from the auxiliary reactor 2 enters the main reactor 4 and is activated at a constant temperature for 3 hours under the conditions of a pressure of 3 MPa, an apparent gas velocity of 0.5 m / s for the reducing gas, and a temperature of 260°C. After the activation, the activated catalyst is removed from the main reactor 4. At the same time, the auxiliary reactor 3 is heated to 260°C after 4 hours of reaction and is connected to the main reactor 4. The intermediate catalyst produced is transported to the main reactor 4 to take over the next constant temperature activation. The auxiliary reactors 2 and 3 must first be cooled to 180°C after unloading, and then a new stream of 16 kg of unactivated catalyst is collected from the feeding tank 1 and subjected to temperature activation under the same reaction conditions as above.

[0090] Auxiliary reactor 2 and auxiliary reactor 3 repeat the above process, and take turns to input the required intermediate catalyst into main reactor 4, so that main reactor 4 can operate continuously without interruption, and activated catalyst can be prepared and continuously provided;

[0091] In the above process, the reaction tail gas discharged from the auxiliary reactor 2 and the auxiliary reactor 3 enters the second heat exchanger 9 for heat exchange with the reducing gas; the reaction tail gas discharged from the main reactor 4 first enters the gas-solid separation device 5 for dust removal, which is a cyclone separator, and then the reaction tail gas after dust removal enters the first heat exchanger 6 for heat exchange with the reducing gas; the reaction tail gas after the above heat exchange is combined and enters the oil washing tower 7, and is further washed to remove the fine catalyst powder particles entrained therein. The washed gas is divided into two streams, one as circulating gas and the other as released gas; the circulating gas enters the gas compression device 8, and after being pressurized, it is mixed with fresh synthesis gas to become reducing gas, and is re-circulated into the system to participate in the activation process.

[0092] In this example, the activation period of a single batch of 16 kg of catalyst is 3 h, and the activated catalyst obtained is recorded as S1 (the yield of S1 is shown in Table 1).

[0093] Example 2

[0094] use Figure 1 The Fischer-Tropsch synthesis catalyst gas-solid phase continuous activation system of the present invention is used to activate the catalyst.

[0095] The operation was carried out according to the method of Example 1, except that: the unactivated catalyst was heated to 160°C in the feeding tank 1; the conditions for temperature activation included: a pressure of 1.5 MPa, an apparent gas velocity of the reducing gas of 0.06 m / s, a heating rate of 40°C / h, a time of 2 h, and a temperature increase to 240°C; the conditions for constant temperature activation included: a pressure of 1 MPa, an apparent gas velocity of the reducing gas of 0.4 m / s, a temperature of 240°C, and a time of 1 h; 1 h after the auxiliary reactor 2 started the temperature increase activation, another 16 kg of unactivated catalyst in the feeding tank 1 was fed into the auxiliary reactor 3, and temperature activation was carried out under the same temperature increase activation reaction conditions as mentioned above, and the temperature was increased to the same target temperature of 240°C; the auxiliary reactor 2 and the auxiliary reactor 3 were both required to be cooled to 160°C after unloading.

[0096] The other operating procedures are the same as those in Example 1, and the main reactor 4 is operated continuously without interruption to prepare and continuously provide the activated catalyst.

[0097] In this example, the activation period of a single batch of 16 kg of catalyst is 1 hour, and the activated catalyst obtained is recorded as S2 (the yield of S2 is shown in Table 1).

[0098] Example 3

[0099] use Figure 1 The Fischer-Tropsch synthesis catalyst gas-solid phase continuous activation system of the present invention is used to activate the catalyst.

[0100] The operation was carried out according to the method of Example 1, except that: the unactivated catalyst was heated to 170°C in the feeding tank 1; the conditions for temperature activation included: pressure of 6.5 MPa, apparent gas velocity of the reducing gas of 0.1 m / s, heating rate of 40°C / h, time of 7 hours, and temperature rising to 450°C; the conditions for constant temperature activation included: pressure of 6 MPa, apparent gas velocity of the reducing gas of 0.7 m / s, temperature of 450°C, and time of 6 hours; after the auxiliary reactor 2 started temperature activation for 6 hours, another 16 kg of unactivated catalyst in the feeding tank 1 was fed into the auxiliary reactor 3, and temperature activation was carried out under the same temperature activation reaction conditions as mentioned above, and the temperature was raised to the same target temperature of 450°C; the auxiliary reactor 2 and the auxiliary reactor 3 were both required to be cooled to 170°C after unloading.

[0101] The other operating procedures are the same as those in Example 1, and the main reactor 4 is operated continuously without interruption to prepare and continuously provide the activated catalyst.

[0102] In this example, the activation period of a single batch of 16 kg of catalyst is 6 h, and the activated catalyst obtained is recorded as S3 (the yield of S3 is shown in Table 1).

[0103] Comparative Example 1

[0104] The unactivated catalyst is loaded into the feeding tank and heated to a temperature of 180°C; then, 16 kg of the unactivated catalyst is fed into a separate activation reactor and temperature activation is carried out for 4 hours under the conditions of a pressure of 3.5 MPa, an apparent gas velocity of the reducing gas of 0.5 m / s, and a heating rate of 20°C / h; when the temperature is raised to 260°C, the temperature activation is completed, and constant temperature activation is continued for 3 hours under the conditions of a pressure of 3 MPa, an apparent gas velocity of the reducing gas of 0.5 m / s, and a temperature of 260°C. After the end, the obtained activated catalyst is removed from the reactor. After unloading, the reactor needs to be cooled down to 180°C at a temperature reduction rate of 20°C / h for 4 hours before a new 16 kg of unactivated catalyst can be fed from the feeding tank and temperature activation and constant temperature activation are carried out in sequence under the same reaction conditions as mentioned above.

[0105] In this comparative example, the activation period of a single batch of 16 kg of catalyst was 11 h, and the activated catalyst obtained was recorded as D1 (the yield of D1 is shown in Table 1).

[0106] Test Case

[0107] The activated catalysts S1-S3 and D1 prepared in Examples 1-3 and Comparative Example 1 were used in Fischer-Tropsch synthesis reaction experiments to evaluate the performance of the catalysts.

[0108] The activated catalysts S1-S3 and D1 were added to a slurry bed Fischer-Tropsch synthesis reactor to carry out Fischer-Tropsch synthesis reaction. The carbon monoxide conversion rate was examined, and the product of the carbon monoxide conversion rate and the catalyst yield in the above embodiment was used as a comprehensive performance index. The performance of the catalysts obtained by different activation methods was compared. The results are shown in Table 1.

[0109] The reaction conditions of the Fischer-Tropsch synthesis are as follows: reaction temperature of 275°C, reaction pressure of 2.8 MPa, inlet gas velocity of 0.18 m / s, and hydrogen-to-carbon ratio (i.e., the molar ratio of hydrogen to carbon monoxide in the inlet gas of the Fischer-Tropsch synthesis reactor) of 4.

[0110] Table 1

[0111] catalyst Carbon monoxide conversion rate / % Catalyst yield / % Comprehensive performance S1 98.7％ 96％ 94.75％ S2 96.5％ 97％ 93.61％ S3 97.2％ 95％ 92.34％ D1 92.8％ 90％ 83.52％

[0112] It can be seen from Table 1 and the above embodiments and comparative examples that the gas-solid phase continuous activation system and method for the Fischer-Tropsch synthesis catalyst provided by the present invention can realize uninterrupted continuous activation reaction, significantly shorten the reaction cycle, and the activated catalyst exhibits better catalytic activity in the Fischer-Tropsch synthesis reaction, a higher carbon monoxide conversion rate, and a higher time-averaged activation capacity of the reactor under the same conditions, and has obvious comprehensive performance advantages, compared with the case of activation using a single activation reactor in the prior art.

[0113] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A method for gas-solid phase continuous activation of a Fischer-Tropsch synthesis catalyst, characterized in that: The method comprises: activating multiple strands of inactivated catalyst by increasing the temperature to obtain multiple strands of intermediate catalyst, and then continuously activating the multiple strands of intermediate catalyst by constant temperature in succession to obtain activated catalyst; The constant temperature activation process includes the following steps: when the first intermediate catalyst completes the previous constant temperature activation, the second intermediate catalyst starts the next constant temperature activation; The system used in the method includes: a main reactor and at least two auxiliary reactors connected in parallel; wherein, The auxiliary reactor is used to heat and activate the unactivated catalyst to obtain an intermediate catalyst; The main reactor is used to activate the intermediate catalyst at a constant temperature to obtain an activated catalyst; The main reactor is connected to only one auxiliary reactor at a time, and when connected, the main reactor has completed the constant temperature activation of the previous intermediate catalyst, and the next intermediate catalyst is input into the main reactor to continue the next constant temperature activation; Wherein, the first stream of intermediate catalyst and the second stream of intermediate catalyst come from different auxiliary reactors; The auxiliary reactor is a bubbling fluidized bed reactor; the main reactor is a high-pressure turbulent fluidized bed reactor.

2. The method according to claim 1, wherein The system further comprises a feeding tank for heating the unactivated catalyst and feeding the unactivated catalyst into the auxiliary reactor in batches.

3. The method according to claim 2, wherein: The system further includes a gas-solid separation device, a first heat exchanger, a second heat exchanger, an oil washing tower and a gas compression device; wherein, The gas-solid separation device is connected to the main reactor and is used to remove dust from the reaction tail gas discharged from the main reactor, remove fine catalyst particles and / or dust therein, and obtain dust-removed reaction tail gas; The first heat exchanger is used to perform heat exchange between the reaction tail gas after dust removal and the reducing gas required for activation; The second heat exchanger is connected to the auxiliary reactor and is used to perform heat exchange between the reaction tail gas discharged from the auxiliary reactor and the reducing gas required for activation; The oil washing tower is connected to the first heat exchanger, the second heat exchanger and the gas compression device respectively, and is used to further wash and remove the catalyst fine particles and / or dust entrained in the reaction tail gas after heat exchange, and divide the washed gas into two streams, one as circulating gas and the other as purge gas; The gas compression device is used to increase the pressure of the circulating gas, and then mix it with fresh synthesis gas to form reducing gas, which continues to circulate and participate in the temperature-raising activation and constant temperature activation.

4. The method according to any one of claims 1 to 3, wherein: The temperature-raising activation is carried out under bubbling fluidization, and the conditions of the temperature-raising activation include: a pressure of 1.5-7 MPa; a superficial velocity of the reducing gas of 0.06-0.1 m / s; and a heating rate of 10-40° C. / h.

5. The method according to claim 4, wherein The temperature-raising activation is carried out under bubbling fluidization, and the conditions of the temperature-raising activation include: a pressure of 2.5-5 MPa; an apparent gas velocity of the reducing gas of 0.06-0.08 m / s; and a heating rate of 20-30° C. / h.

6. The method according to any one of claims 1 to 3, wherein before the temperature-raising activation, the temperature of the unactivated catalyst is heated to 160-180°C; And / or, the constant temperature activation is carried out under turbulent fluidization, and the conditions of the constant temperature activation include: The pressure is 1-6MPa; The superficial velocity of the reducing gas is 0.3-0.9 m / s; The temperature is 240-450℃; the time is 1-6h; And / or, the pressure of the temperature-raising activation is 0.5-1 MPa higher than the pressure of the constant temperature activation; And / or, the temperature finally raised to by the temperature-raising activation is the same as the temperature of the constant-temperature activation.

7. The method according to claim 6, wherein the constant temperature activation is carried out under turbulent fluidization, and the conditions of the constant temperature activation include: The pressure is 2-4 MPa; The superficial velocity of the reducing gas is 0.4-0.7 m / s; The temperature is 260-350℃; the time is 3-4h.

8. The method according to any one of claims 1 to 3, 5 and 7, wherein: The method further comprises: Heat exchange is performed between the reaction tail gas activated by heating and the reducing gas required for activation; The reaction tail gas activated at constant temperature is dedusted, and the dedusted reaction tail gas is heat exchanged with the reducing gas required for activation; The reaction tail gas after the above heat exchange is oil washed to further remove the fine catalyst particles and / or dust entrained therein, and the washed gas is divided into two streams, one of which is released as purge gas, and the other is mixed with fresh synthesis gas as circulating gas to become reducing gas, which continues to circulate and participate in the above temperature-raising activation and constant temperature activation.

9. The method according to claim 4, wherein: The method further comprises: Heat exchange is performed between the reaction tail gas activated by heating and the reducing gas required for activation; The reaction tail gas activated at constant temperature is dedusted, and the dedusted reaction tail gas is heat exchanged with the reducing gas required for activation; The reaction tail gas after the above heat exchange is oil washed to further remove the fine catalyst particles and / or dust entrained therein, and the washed gas is divided into two streams, one of which is released as purge gas, and the other is mixed with fresh synthesis gas as circulating gas to become reducing gas, which continues to circulate and participate in the above temperature-raising activation and constant temperature activation.

10. The method according to claim 6, wherein: The method further comprises: Heat exchange is performed between the reaction tail gas activated by heating and the reducing gas required for activation; The reaction tail gas activated at constant temperature is dedusted, and the dedusted reaction tail gas is heat exchanged with the reducing gas required for activation; The reaction tail gas after the above heat exchange is oil washed to further remove the fine catalyst particles and / or dust entrained therein, and the washed gas is divided into two streams, one of which is released as purge gas, and the other is mixed with fresh synthesis gas as circulating gas to become reducing gas, which continues to circulate and participate in the above temperature-raising activation and constant temperature activation.

11. The method according to any one of claims 1-3, 5, 7, 9-10, wherein: The unactivated catalyst is an iron-based catalyst or a cobalt-based catalyst for Fischer-Tropsch synthesis reaction in which the active components are in an oxidized state.

12. The method according to claim 4, wherein: The unactivated catalyst is an iron-based catalyst or a cobalt-based catalyst for Fischer-Tropsch synthesis reaction in which the active components are in an oxidized state.

13. The method according to claim 6, wherein: The unactivated catalyst is an iron-based catalyst or a cobalt-based catalyst for Fischer-Tropsch synthesis reaction in which the active components are in an oxidized state.

14. The method according to claim 8, wherein The unactivated catalyst is an iron-based catalyst or a cobalt-based catalyst for Fischer-Tropsch synthesis reaction in which the active components are in an oxidized state.

15. Use of the method according to any one of claims 1 to 14 in Fischer-Tropsch synthesis reaction.

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