Heating reduction method for preparing cyclohexanone catalyst through dehydrogenation of copper-silicon cyclohexanol

Abstract

The invention discloses a heating reduction method of a copper-silicon cyclohexanol dehydrogenation cyclohexanone catalyst. The method comprises the following steps: step 1, raising the temperature in a reactor to 170-190 DEG C and keeping the temperature for 2 hours; step 2, introducing reducing gas into the reactor to carry out reduction reaction on the catalyst in the reactor; the reduction reaction comprises an initial reduction stage, a middle reduction stage and a final reduction stage; the hot-spot temperature of a bed layer in the reactor at the initial stage of reduction, the middle stage of reduction and the final stage of reduction is controlled not to exceed 250 DEG C by adjusting the temperature and the flow speed of the heat transfer medium and / or the concentration of hydrogen in the reducing gas. According to the method, the reduction reaction process of the copper-silicon catalyst is divided into the initial reduction stage, the middle reduction stage and the final reduction stage, and accurate control is respectively performed according to different reaction stages and different modes, so that the technical effects of effectively controlling the reaction temperature in the reduction process of the copper-silicon catalyst and ensuring that the catalyst has excellent activity are realized.

Description

Technical Field

[0001] The invention belongs to the technical field of copper-silicon catalysts, and in particular relates to a temperature-raising reduction method for a copper-silicon cyclohexanol dehydrogenation catalyst to prepare cyclohexanone. Background Art

[0002] Cyclohexanone is an important organic chemical raw material, a saturated cyclic ketone with a carbonyl carbon atom in a six-membered ring. It is an important intermediate for the preparation of nylon-66 and nylon-6, and is widely used in the fields of pesticides, medicines, synthetic fibers, and organic solvents, with important industrial and economic value. At present, the production of cyclohexanone is mainly achieved through the catalytic dehydrogenation of cyclohexanol, among which how to obtain an efficient and stable catalyst is the key technology in the catalytic dehydrogenation of cyclohexanol to prepare cyclohexanone.

[0003] At present, the catalyst for the gas-phase dehydrogenation of cyclohexanol to cyclohexanone commonly used in industry is a copper-based catalyst. Compared with the red iron oxide catalyst and zinc-based catalyst used in the early stage, the copper-based catalyst can obtain a higher conversion rate selectivity at a lower catalytic temperature when used, so it is widely used. Copper-silicon-based catalysts are one of the copper-based catalysts. The active components of this type of catalyst are in the state of metal oxides before leaving the factory. Before use, CuO and Si must be reduced to form Cu-Si active centers. Different reduction conditions will generate different Cu-Si active centers. Therefore, the reduction control process of copper-silicon-based catalysts has a significant impact on their activity. Unlike copper-zinc-based catalysts, copper-silicon-based catalysts are heat-sensitive catalysts. If the temperature is improperly controlled or the concentration of the reducing agent is too high during the reduction process, the reaction process will be overheated locally, causing the copper grains to sinter, thereby reducing the active specific surface area of ​​the catalyst, and then the activity and life of the catalyst will be seriously damaged. Summary of the invention

[0004] The present invention aims to solve the technical problems in the prior art that, because copper-silicon based catalysts are heat-sensitive catalysts, they are prone to overheating of the catalyst locally due to improper reaction temperature control during the reduction process, causing copper grains to sinter and affecting the activity and life of the catalyst. A temperature-raising reduction method for a copper-silicon based cyclohexanol dehydrogenation catalyst to produce cyclohexanone is proposed, so as to achieve the technical effect of effectively controlling the reaction temperature during the reduction process of the copper-silicon based catalyst and ensuring that the catalyst has excellent activity.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme:

[0006] A temperature-raising reduction method for a copper-silicon-based cyclohexanol dehydrogenation catalyst to produce cyclohexanone comprises the following steps:

[0007] Step 1: Heating the bed inside the reactor

[0008] Raise the temperature in the reactor to 170-190°C and maintain for 2h;

[0009] Step 2: Reducing the catalyst on the bed inside the reactor

[0010] Introducing reducing gas into the reactor to perform a reduction reaction on the catalyst inside the reactor; the reduction reaction includes an initial reduction stage, a middle reduction stage and a final reduction stage;

[0011] In the initial stage of reduction, the hot spot temperature of the bed in the reactor is controlled by adjusting the temperature and flow rate of the heat transfer medium and the concentration of hydrogen in the reducing gas to ensure that the hot spot temperature does not exceed the maximum preset temperature;

[0012] In the initial stage of reduction, the volume concentration of hydrogen in the reducing gas is first increased, and then the hot spot temperature of the bed in the reactor is controlled by adjusting the temperature and flow rate of the heat transfer medium to ensure that the hot spot temperature does not exceed the maximum preset temperature; when the hot spot temperature of the bed in the reactor cannot be controlled to not exceed the maximum preset temperature by adjusting the temperature and flow rate of the heat transfer medium, the hot spot temperature in the reactor is controlled by intermittently introducing reducing gas into the reactor;

[0013] In the final stage of reduction, the hot spot temperature of the bed in the reactor is increased by increasing the hydrogen concentration in the reducing gas to perform deep reduction on the catalyst, until the bed temperature in the reactor rises to the set temperature and the hydrogen concentrations in the reducing gas at the inlet and outlet ends of the reactor are consistent, the temperature-raising reduction process of the catalyst is completed.

[0014] Furthermore, the temperature rise process of the reactor in step 1 is: from room temperature to 60°C in the first 2 hours, from 60°C to 120°C during 2 hours to 8 hours, and from 120°C to 170-190°C during 8 hours to 18 hours.

[0015] Furthermore, the reducing gas is a hydrogen-nitrogen mixed gas, and the volume concentration of hydrogen in the initial reducing gas introduced into the reactor is 2%.

[0016] Furthermore, the method for controlling the hot spot temperature of the bed in the reactor by adjusting the temperature and flow rate of the heat transfer medium and the concentration of hydrogen in the reducing gas at the initial stage of reduction is: when the hot spot temperature of the bed in the reactor is greater than a set value, the temperature of the heat transfer medium is lowered, the flow rate of the heat transfer medium is increased, and / or the concentration of hydrogen in the reducing gas is reduced until the hot spot temperature of the bed in the reactor drops to a set range; when it is necessary to increase the hot spot temperature of the bed in the reactor, the concentration of hydrogen in the reducing gas is increased and / or the flow rate of the heat transfer medium is reduced to increase the hot spot temperature of the bed in the reactor to a preset range.

[0017] Furthermore, the intermittent introduction of reducing gas into the reactor is as follows: when the hot spot temperature exceeds the maximum preset temperature, the introduction of reducing gas into the reactor should be stopped immediately; after the hot spot temperature in the reactor drops to the minimum preset temperature, reducing gas is introduced into the reactor at a rate of 1 to 2 minutes every 10 to 30 minutes, so that the hot spot temperature in the reactor does not exceed the maximum preset temperature.

[0018] Furthermore, in the initial stage of reduction, the hot spot temperature rise rate of the bed layer in the reactor is ≤20°C / h, and the temperature drift of the hot spot does not exceed 5°C.

[0019] Furthermore, the volume concentration of hydrogen in the reducing gas in the initial stage of reduction is 0.5-3%, and the volume concentration of hydrogen in the reducing gas in the middle stage of reduction is 3-4%.

[0020] Furthermore, in the middle stage of the reduction, the hot spot temperature rise rate of the bed layer in the reactor is ≤20°C / h, and the temperature drift of the hot spot does not exceed 10°C.

[0021] Furthermore, in the final stage of the reduction, the hot spot temperature rise rate of the bed layer in the reactor is ≤5°C / h, and the temperature drift of the hot spot does not exceed 2°C.

[0022] Furthermore, the volume concentration of hydrogen in the reducing gas at the final stage of the reduction is 4-25%, and the volume concentration of hydrogen in the reducing gas in the reactor accumulates to more than 25% when the reduction reaction is finished.

[0023] The beneficial effects of the present invention are:

[0024] The present invention divides the reduction reaction process of the copper-silicon catalyst into the initial reduction stage, the middle reduction stage and the final reduction stage, and then accurately controls the different reaction stages in different ways, thereby effectively controlling the reaction temperature during the reduction process of the copper-silicon catalyst and ensuring that the catalyst has excellent activity. Specifically:

[0025] For the conventionally used reactor in the prior art, the catalyst reduction state at the air inlet and outlet of the reactor is inconsistent during the reduction process (especially the initial stage and the mid-stage of reduction). In the initial stage of reduction, a large amount of reducing gas is introduced into the air inlet of the reactor. At this time, the reducing gas first undergoes a reduction reaction with the surface of the catalyst particles on the bed near the air inlet of the reactor. During the reaction, the exothermic area is concentrated, and overheating is prone to occur. Therefore, this area should be selected as the key temperature monitoring area when performing temperature control. In the mid-stage of reduction, since the reduction reaction on the surface of the catalyst particles on the bed near the air inlet of the reactor is coming to an end (the subsequent reducing gas will also undergo a deep reduction reaction with the catalyst in this area, but the deep reduction reaction will not generate too much heat), a large amount of reducing gas gradually enters the air outlet of the reactor and undergoes a reduction reaction with the surface of the catalyst particles on the bed in this area. In the mid-stage of reduction, this area is the main reduction reaction area, and the temperature of this area needs to be focused on. At the late stage of reduction, the surfaces of all catalysts in the reactor have completed the reduction reaction. At this time, it is necessary to increase the concentration of hydrogen in the reducing gas to increase the penetration of the reducing gas in the catalyst and improve the reduction reaction. Compared with the catalyst near the gas outlet of the reactor, the catalyst near the gas inlet of the reactor reacts more completely. Therefore, in the late stage of reduction, it is still necessary to focus on the reaction temperature of the catalyst area on the bed near the gas outlet of the reactor. Therefore, according to the existing temperature control method, it is impossible to accurately control the temperature of the reduction reaction of the copper-silicon system. Regardless of whether it is in the initial stage of reduction, the middle stage of reduction or the final stage of reduction, the hot spot temperature is the reaction temperature of the area with the most intense reaction. Based on this, the present invention uses the hot spot temperature as a parameter indicator of the temperature control process, and then cooperates with the temperature control methods of different stages to achieve accurate control of the reaction temperature of the catalyst reduction process in the reactor, effectively avoiding the sintering of copper grains due to excessive local temperature during the catalyst reduction process, and the catalyst activity specific surface area is reduced, thereby causing the activity and life of the catalyst to be seriously damaged. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a temperature-raising reduction curve diagram of each stage in the embodiment.

[0027] Figure 2 This is an electron microscope image of the catalyst obtained in Example. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be described more clearly and completely below. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meaning understood by people with general skills in the field to which the present invention belongs.

[0029] The words "first", "second" and similar words used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular forms of "one", "an" or "the" and similar words do not indicate a quantitative limitation, but indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before "include" or "comprise" cover the features, wholes, steps, operations, elements and / or components listed after "include" or "comprise", and do not exclude the existence or addition of one or more other features, wholes, steps, operations, elements, components and / or their collections. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0030] Example

[0031] A temperature-raising reduction method for a copper-silicon-based cyclohexanol dehydrogenation catalyst to produce cyclohexanone comprises the following steps:

[0032] Step 1: Heating the internal bed of the axial shell and tube reactor

[0033] The bed temperature inside the axial shell and tube reactor is raised to 180°C and maintained for 2h; wherein the heating process is as shown in Table 1: from room temperature to 60°C in the first 2h, from 60°C to 120°C during 2h to 8h, and from 120°C to 180°C during 8h to 18h. This embodiment adopts a vertical axial shell and tube reactor. After completing the heating process, it is necessary to observe that the temperature of the catalyst in the upper part of the axial shell and tube reactor (i.e., the position close to the air inlet end of the reactor) must be raised to 180°C to ensure that the hydrogen can fully react when passing through this area during the reduction process, so as to avoid the accumulation of hydrogen in the initial stage of reduction due to incomplete reaction, resulting in violent local reaction and overheating. During the heating process, the air velocity in the reduction area of ​​the reactor is 1000h-1.

[0034] Step 2: Reducing the catalyst on the inner bed of the axial shell and tube reactor

[0035] Reducing gas is introduced into the gas inlet at the top of the axial shell-and-tube reactor to carry out a reduction reaction on the catalyst inside the reactor; the reducing gas is a hydrogen-nitrogen mixed gas, and the hydrogen volume concentration in the initial reducing gas introduced into the axial shell-and-tube reactor is 2%. During the reduction reaction, the space velocity in the reduction zone of the reactor is always maintained at 1000h-1. In order to accurately control the temperature of the reduction process, the reduction reaction includes an initial reduction stage, a middle reduction stage and a final reduction stage; and the corresponding temperature control is performed on the above three stages respectively to adapt to the reaction state of the catalyst at different stages, so as to achieve the technical effect of accurately controlling the catalyst reduction reaction temperature and ensuring that the catalyst has excellent activity.

[0036] As shown in Table 1 and Figure 1 As shown, in this embodiment, the initial reduction stage is the first 57 hours after the reduction reaction, the mid-reduction stage is the 57th to 77th hour of the reduction reaction, and the final reduction stage is the 77th to 89th hour of the reduction reaction. However, it should be noted that in actual application, the specific time of the initial reduction stage, the mid-reduction stage and the final reduction stage is not limited to the above time. Technicians in this field determine the specific reduction stage according to the reduction state of the catalyst during actual operation. The specific determination and control process of the above three stages are as follows:

[0037] In the initial stage of reduction, a large amount of reducing gas is introduced into the air inlet of the axial shell and tube reactor. At this time, the reducing gas first reacts with the surface of the catalyst particles on the bed near the air inlet of the reactor. At this time, this area is the main area of ​​the reduction reaction. The heat released during the reaction is also mainly concentrated in this area, so this area is prone to overheating. Therefore, this area should be selected as the main temperature monitoring area when temperature control is performed in the initial stage of reduction. When reducing gas with a hydrogen volume concentration of 2% is introduced into the air inlet at the top of the axial shell and tube reactor, the reduction energy density per unit volume of the reducing gas is 77.32 kJ / Nm 3 (gas), with the space velocity in the reduction zone as 1000h -1 The calculated heat of reaction per unit volume of catalyst per unit time is 77,320 kJ / (m 3cat.h). In the first 38 hours after the reduction reaction begins, the hotspot temperature in the reactor can be controlled between 180°C and 190°C by increasing the amount of steam released from the drum to increase the vaporization heat transfer capacity and increasing the circulating gas flow rate under the system pressure to improve the heat transfer efficiency. The temperature of the hotspot in the reactor continues to rise during the 38-57 hours of the reduction reaction. At this time, the volume concentration of hydrogen in the reducing gas is reduced to between 0.5% and 1% to further reduce the rate of the reduction reaction and control the hotspot temperature in the reactor between 190 and 220°C. At the same time, in the above control process, it is also necessary to ensure that the hotspot temperature increase rate of the bed in the reactor in the initial stage of the reduction is ≤20°C / h, and the temperature drift of the hotspot does not exceed 5°C.

[0038] After the above-mentioned initial stage of reduction, the surface reduction reaction of the catalyst particles on the bed near the air inlet end of the reactor comes to an end (the subsequent reducing gas will also undergo a deep reduction reaction with the catalyst in this area, but the deep reduction reaction will not generate too much heat), and a large amount of reducing gas gradually enters the outlet end of the reactor and undergoes a reduction reaction with the surface of the catalyst particles on the bed in this area. At this time, it enters the middle stage of reduction. Since the surface reduction reaction of the catalyst particles on the bed has come to an end, it is difficult for the reducing gas to enter the deep layer of the catalyst particles, the reaction rate gradually decreases, the heat release decreases, and the reduction reaction time is prolonged, affecting the catalyst performance. To this end, at this stage, the volume concentration of hydrogen in the reducing gas should first be increased to 3-4% to ensure that the reducing gas near the air inlet end of the reactor can be deeply reduced. However, since the main reduction reaction area is located near the outlet end of the reactor at this time, the reaction temperature in this area should be focused on. By increasing the release of drum steam to increase the vaporization heat transfer capacity and increasing the circulating gas under system pressure to improve the heat transfer efficiency, the hot spot temperature is ensured not to exceed 220°C. When the method of increasing the release of drum steam to increase the vaporization heat transfer capacity and increasing the circulating gas flow rate under the system pressure to improve the heat transfer efficiency cannot ensure that the hot spot temperature does not exceed 220°C, the temperature should be further adjusted by intermittently introducing reducing gas into the reactor. That is, when the temperature exceeds 220°C, the introduction of reducing gas into the reactor should be stopped immediately. After the hot spot temperature in the reactor drops to 190°C, the reducing gas should be introduced into the reactor every 10 to 30 minutes for 1 to 2 minutes to ensure that the hot spot temperature in the reactor does not exceed 220°C. It should be noted that after each interval of introducing reducing gas, it is necessary to wait until the hot spot temperature in the reactor drops to 190°C before the next reduction gas compensation. At the same time, in the above control process, it is also necessary to ensure that the hot spot temperature increase rate of the bed in the reactor in the middle of the reduction period is ≤20°C / h, and the temperature drift of the hot spot does not exceed 10°C.

[0039] As the reduction reaction proceeds, it gradually enters the final stage of reduction. The surfaces of all catalysts in the reactor complete the reduction reaction, and the reduction reaction begins to weaken. At this time, it is necessary to increase the concentration of hydrogen in the reducing gas to increase the temperature of the bed in the reactor and thereby increase the penetration of the reducing gas in the catalyst, and ultimately increase the reduction reaction to improve the reduction effect of the catalyst. In this stage, the volume concentration of hydrogen in the reducing gas is 4-25%, and the hot spot temperature increase rate of the bed in the reactor is controlled to be ≤5°C / h, and the temperature drift of the hot spot does not exceed 2°C. At the end of the reduction reaction, the volume concentration of hydrogen in the reducing gas in the reactor accumulates to more than 25%. When the hydrogen concentrations in the reducing gas at the air inlet and outlet ends of the reactor are the same, the temperature increase reduction process of the catalyst ends. Figure 2 As shown, the Cu grain size in the reduced catalyst obtained in this example is 12.4 nm.

[0040] Table 1 Hot spot temperature at each stage of the catalyst reduction reaction and the volume concentration of hydrogen introduced

[0041]

[0042] Verification test

[0043] In order to verify the catalytic effect of the catalyst obtained in the above example, the above reduced catalyst was used in the reaction of dehydrogenating cyclohexanol to prepare cyclohexanone, wherein the catalyst loading in the reaction was 50 ml and the liquid space velocity of the raw material cyclohexanol was 0.60 h -1 , the reducing gas is H2 gas, the reaction temperature is 230°C, and the reaction results are shown in Table 2 below.

[0044] Table 2 Reaction results of the embodiment applied to cyclohexanol dehydrogenation to prepare cyclohexanone

[0045] Cyclohexanol conversion ≥50％ Cyclohexanone selectivity ≥99％ <![CDATA[Output, t 环己酮 / m 3 cat > ≥0.72

[0046] As can be seen from Table 2, the catalyst prepared by the present invention can obtain a higher conversion rate, selectivity and yield in the reaction of preparing cyclohexanone by dehydrogenation of cyclohexanol, which shows that the catalyst has excellent activity and good catalytic effect.

[0047] In this regard, in-situ EXAFS technology was used to study the reduction of Cu-Si catalysts with a certain composition structure in a hydrogen atmosphere. The structure around the copper atoms has different assumed forms as the reaction temperature increases. This can be explained by the following three structures:

[0048] When the reaction temperature is lower than 154°C, a quasi-two-dimensional structure of copper is epitaxially grown on the surface of the Si support;

[0049] When the reaction temperature is between 154 and 270 °C, small clusters of copper atoms begin to disperse on the Si surface;

[0050] When the reaction temperature is higher than 270°C, the copper grains dispersed on the Si surface grow.

[0051] In a strong reducing atmosphere, the coordination number of Cu-Si is the smallest and the catalyst activity is the highest. However, under very harsh conditions (>300°C), the single substance structure of Cu will be reduced, resulting in a decrease in the activity of the catalyst. Therefore, in application, the copper-silicon catalyst requires the apparent hot spot temperature not to exceed 250°C during reduction. The present invention adopts the above-mentioned temperature increase reduction control method to ensure that the hot spot temperature of the catalyst does not exceed 250°C during the entire reduction process, so that the active center of the catalyst can be generated at a lower temperature, thereby giving full play to the catalytic performance of the catalyst.

[0052] Finally, it should be noted that these embodiments are only used to illustrate the present invention and do not limit the scope of the present invention. In addition, for those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. The obvious changes or modifications derived from them are still within the scope of protection of the present invention.

Claims

1. A temperature-raising reduction method for a copper-silicon-based cyclohexanol dehydrogenation catalyst to produce cyclohexanone, characterized in that: The steps include: Step 1: Heating the bed inside the reactor Raise the temperature in the reactor to 170-190°C and maintain for 2h; Step 2: Reducing the catalyst on the bed inside the reactor Introducing reducing gas into the reactor to perform a reduction reaction on the catalyst inside the reactor; the reduction reaction includes an initial reduction stage, a middle reduction stage and a final reduction stage; In the initial stage of reduction, the hot spot temperature of the bed in the reactor is controlled by adjusting the temperature and flow rate of the heat transfer medium and the concentration of hydrogen in the reducing gas to ensure that the hot spot temperature does not exceed the maximum preset temperature; In the initial stage of reduction, the volume concentration of hydrogen in the reducing gas is first increased, and then the hot spot temperature of the bed in the reactor is controlled by adjusting the temperature and flow rate of the heat transfer medium to ensure that the hot spot temperature does not exceed the maximum preset temperature; when the hot spot temperature of the bed in the reactor cannot be controlled to not exceed the maximum preset temperature by adjusting the temperature and flow rate of the heat transfer medium, the hot spot temperature in the reactor is controlled by intermittently introducing reducing gas into the reactor; In the final stage of reduction, the hot spot temperature of the bed in the reactor is increased by increasing the hydrogen concentration in the reducing gas to perform deep reduction on the catalyst, until the bed temperature in the reactor rises to the set temperature and the hydrogen concentrations in the reducing gas at the inlet and outlet ends of the reactor are consistent, the temperature-raising reduction process of the catalyst is completed.

2. The temperature-raising reduction method of a copper-silicon-based cyclohexanol dehydrogenation catalyst to cyclohexanone according to claim 1, characterized in that: The temperature rise process of the reactor in step 1 is as follows: from room temperature to 60°C in the first 2 hours, from 60°C to 120°C during 2 hours to 8 hours, and from 120°C to 170-190°C during 8 hours to 18 hours.

3. The temperature-raising reduction method of a copper-silicon-based cyclohexanol dehydrogenation catalyst to cyclohexanone according to claim 1, characterized in that: The reducing gas is a hydrogen-nitrogen mixed gas, and the volume concentration of hydrogen in the initial reducing gas introduced into the reactor is 2%.

4. The temperature-raising reduction method of a copper-silicon-based cyclohexanol dehydrogenation catalyst to cyclohexanone according to claim 1, characterized in that: The method for controlling the hot spot temperature of the bed in the reactor by adjusting the temperature and flow rate of the heat transfer medium and the concentration of hydrogen in the reducing gas in the initial stage of reduction is as follows: when the hot spot temperature of the bed in the reactor is greater than a set value, the temperature of the heat transfer medium is reduced, the flow rate of the heat transfer medium is increased, and / or the concentration of hydrogen in the reducing gas is reduced until the hot spot temperature of the bed in the reactor drops to a set range; when it is necessary to increase the hot spot temperature of the bed in the reactor, the concentration of hydrogen in the reducing gas is increased and / or the flow rate of the heat transfer medium is reduced to increase the hot spot temperature of the bed in the reactor to a preset range.

5. The temperature-raising reduction method of a copper-silicon-based cyclohexanol dehydrogenation catalyst to cyclohexanone according to claim 1, characterized in that: The method of intermittently introducing reducing gas into the reactor is as follows: when the hot spot temperature exceeds the maximum preset temperature, the introduction of reducing gas into the reactor should be stopped immediately. After the hot spot temperature in the reactor drops to the minimum preset temperature, the reducing gas is introduced into the reactor at a ventilation time of 1 to 2 minutes every 10 to 30 minutes, so that the hot spot temperature in the reactor does not exceed the maximum preset temperature.

6. The temperature-raising reduction method of a copper-silicon-based cyclohexanol dehydrogenation catalyst to cyclohexanone according to claim 1, characterized in that: In the initial stage of reduction, the hot spot temperature rise rate of the bed layer in the reactor is ≤20°C / h, and the temperature drift of the hot spot does not exceed 5°C.

7. The temperature-raising reduction method of a copper-silicon-based cyclohexanol dehydrogenation catalyst to cyclohexanone according to claim 1, characterized in that: In the initial stage of reduction, the volume concentration of hydrogen in the reducing gas is 0.5-3%, and in the middle stage of reduction, the volume concentration of hydrogen in the reducing gas is 3-4%.

8. The temperature-raising reduction method of a copper-silicon-based cyclohexanol dehydrogenation catalyst to cyclohexanone according to claim 1, characterized in that: In the middle stage of the reduction, the temperature rise rate of the hot spot of the bed in the reactor is ≤20°C / h, and the temperature drift of the hot spot does not exceed 10°C.

9. The temperature-raising reduction method of a copper-silicon-based cyclohexanol dehydrogenation catalyst to cyclohexanone according to claim 1, characterized in that: The hot spot temperature rise rate of the bed layer in the reactor in the final stage of the reduction is ≤5°C / h, and the temperature drift of the hot spot does not exceed 2°C.

10. The temperature-raising reduction method of a copper-silicon-based cyclohexanol dehydrogenation catalyst to cyclohexanone according to claim 1, characterized in that: The volume concentration of hydrogen in the reducing gas is 4-25% in the final stage of the reduction, and the volume concentration of hydrogen in the reducing gas in the reactor accumulates to more than 25% when the reduction reaction is finished.

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