Catalyst state determination method and catalyst state determination apparatus

Abstract

This invention provides a catalyst state determination method that can determine the future state of the catalyst. [Solution] The catalyst state determination method involves a reactor 12 that generates hydrocarbons by contacting a catalyst 15 with raw materials containing carbon dioxide and hydrogen, measuring the temperature of the catalyst 15 heated by the generation of hydrocarbons at multiple measurement positions PO along the direction in which the raw materials flow, and determining the state of the catalyst 15 based on the relationship between the multiple measurement positions PO and the temperatures of the catalyst 15 measured at the multiple measurement positions PO.

Description

Technical Field

[0001] The present disclosure relates to a catalyst state determination method and a catalyst state determination device.

Background Art

[0002] Hydrocarbons are widely used as an energy source and a raw material for chemical products, and many of them are produced from fossil fuels. However, when products derived from fossil fuels are burned, the concentration of carbon dioxide in the atmosphere, which is regarded as a cause of global warming, increases. On the other hand, hydrocarbons can be produced from raw materials containing carbon dioxide. For example, by producing hydrocarbons from carbon dioxide contained in exhaust gas from factories and the like, it is expected to suppress carbon dioxide emissions.

[0003] Patent Document 1 discloses a monitoring method for monitoring the state of a catalyst used in a methane production reaction in which carbon dioxide and hydrogen are continuously reacted in a reactor in the presence of a catalyst to produce methane. In this monitoring method, the amount of hydrogen supplied into the reactor is increased at predetermined intervals within a certain period of time, the change in the reaction efficiency of the methane production reaction with respect to the increase in the amount of hydrogen supplied is measured, and the state of the catalyst is monitored based on the change in the reaction efficiency.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] According to the monitoring method described in Patent Document 1, it is possible to grasp the factors causing a decrease in the reaction efficiency in the methane production reaction. However, with the conventional monitoring method, it is not possible to grasp the state of the catalyst in the future.

[0006] Therefore, the purpose of this disclosure is to provide a catalyst state determination method and a catalyst state determination apparatus capable of determining the future state of a catalyst. [Means for solving the problem]

[0007] The catalyst state determination method according to this disclosure involves a reactor that produces hydrocarbons by contacting a catalyst with raw materials containing carbon dioxide and hydrogen, and measuring the temperature of the catalyst heated by the production of hydrocarbons at multiple measurement positions along the direction in which the raw materials flow. The catalyst state determination method determines the state of the catalyst based on the relationship between the multiple measurement positions and the catalyst temperatures measured at the multiple measurement positions.

[0008] The catalyst state may include at least one selected from the group consisting of catalyst degradation state, remaining lifespan, and replacement timing.

[0009] The first peak top position in the current operating state, where the catalyst temperature is at its maximum in the direction of raw material flow, may be estimated based on the relationship between multiple measurement positions and the catalyst temperature measured at each of those positions. The state of the catalyst may be determined based on the first peak top position.

[0010] The state of the catalyst may also be determined based on the relationship between the first peak top position, the second peak top position where the catalyst temperature is at its maximum value at the start of catalyst use, and the third peak top position where the catalyst temperature is at its maximum value at the time of catalyst replacement.

[0011] The state of the catalyst may be determined based on the first peak top position and the time the catalyst is used to reach the first peak top position from the second peak top position.

[0012] The catalyst state determination device is used in a reactor that produces hydrocarbons by contacting a catalyst with raw materials containing carbon dioxide and hydrogen. It includes an input unit that receives the temperature of the catalyst, which is measured at multiple measurement positions along the direction of flow of the raw materials and heated by the production of hydrocarbons. The catalyst state determination device includes a controller that determines the state of the catalyst based on the relationship between the multiple measurement positions and the catalyst temperatures measured at the multiple measurement positions. [Effects of the Invention]

[0013] According to this disclosure, it is possible to provide a catalyst state determination method and a catalyst state determination apparatus that can determine the future state of the catalyst. [Brief explanation of the drawing]

[0014] [Figure 1] This is a block diagram showing a catalyst state determination device according to one embodiment. [Figure 2] This is a schematic diagram showing a reaction apparatus according to one embodiment. [Figure 3] This is a schematic diagram showing the state of the reactor and measurement unit according to one embodiment. [Figure 4] This graph shows how the peak temperature of the catalyst changes over time. [Figure 5] This graph illustrates a method for calculating the remaining lifespan and replacement timing of a catalyst. [Figure 6] This flowchart shows the procedure for determining the remaining lifespan of a catalyst. [Figure 7] This flowchart shows the procedure for determining when to replace the catalyst. [Modes for carrying out the invention]

[0015] Several exemplary embodiments will be described below with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from the actual ratios.

[0016] As shown in FIG. 1, the catalyst state determination device 1 according to the present embodiment includes a reactor 10, a measurement unit 20, an input unit 30, a controller 40, and an output unit 50. The measurement unit 20 and the input unit 30 are electrically communicably connected. Also, the input unit 30, the controller 40, and the output unit 50 are electrically communicably connected.

[0017] As shown in FIG. 2, the reactor 10 produces hydrocarbons from a raw material containing carbon dioxide and hydrogen. For example, as shown in the following reaction formula (1), the reactor 10 produces methane from a raw material containing carbon dioxide and hydrogen. CO2 + 4H2 → CH4 + 2H2O (1)

[0018] As shown in FIG. 2, the reactor 10 according to the present embodiment may include a heater 11, a reactor 12, a cooler 13, and a gas-liquid separator 14. The heater 11 heats the raw material supplied to the reactor 12. The reactor 12 produces hydrocarbons from a raw material containing carbon dioxide and hydrogen. The reactor 12 also produces water vapor as a by-product. The cooler 13 cools the product containing the hydrocarbons and water vapor produced in the reactor 12. The gas-liquid separator 14 separates the hydrocarbons produced in the reactor 12 from the water produced in the reactor 12 and condensed by cooling in the cooler 13.

[0019] As shown in FIG. 3, in the present embodiment, the reactor 12 includes a reaction tube 16, and the catalyst 15 is filled in the reaction tube 16. Thereby, the raw material passes through the reaction tube 16 and contacts the catalyst 15. Therefore, the reactor 12 generates hydrocarbons by bringing the raw material containing carbon dioxide and hydrogen into contact with the catalyst 15. The carbon dioxide supplied to the reactor 12 may contain carbon dioxide recovered from a power plant or a factory. By using such carbon dioxide as a raw material, not only can the amount of carbon dioxide discharged from the power plant or the factory be reduced, but the carbon dioxide can also be effectively utilized. Further, the hydrogen supplied to the reactor 12 may be obtained by electrolyzing water using renewable energy such as sunlight, wind power, and hydraulic power. By using such hydrogen, the carbon dioxide emission amount of the entire system can be reduced.

[0020] The reactor 12 may include a fixed bed reactor. The fixed bed reactor may be a single tube reactor or a multi-tube reactor such as a shell and tube reactor. The fixed bed reactor may include a reaction tube 16 and a shell (not shown) that houses the reaction tube 16. The reaction of generating hydrocarbons from a raw material containing carbon dioxide and hydrogen is an exothermic reaction. Therefore, by passing a heat medium such as oil through the shell, the reaction heat generated by generating hydrocarbons can be taken away, and the reaction can be promoted.

[0021] The hydrocarbons produced in reactor 12 may include at least one of alkanes and alkenes. These hydrocarbons can be produced by a methanation reaction or a Fischer-Tropsch (FT) reaction. The hydrocarbons produced in reactor 12 may be used as sustainable aviation fuel (SAF). At least one of the alkanes and alkenes may contain at least one hydrocarbon having 1 to 100 carbon atoms. At least one of the alkanes and alkenes may contain at least one hydrocarbon having 1 to 4 carbon atoms. The alkanes may include, for example, at least one selected from the group consisting of methane, ethane, propane, and butane. The alkenes may include, for example, at least one selected from the group consisting of ethylene, propylene, 1-butene, 2-butene, isobutene, and 1,3-butadiene. Methane, ethane, and propane can be used as fuel for city gas. In addition, alkenes with 2 to 4 carbon atoms are useful as raw materials for plastics. The reaction products generated in reactor 12 may also contain compounds other than those mentioned above.

[0022] Catalyst 15 may include at least one selected from the group consisting of, for example, nickel catalysts, ruthenium catalysts, iron catalysts, and cobalt catalysts. Catalyst 15 can be selected from the viewpoint of the type of hydrocarbon produced. Nickel catalysts or ruthenium catalysts can be used in methanation reactions to produce methane. Iron catalysts and cobalt catalysts can be used in FT reactions. Iron catalysts can mainly produce light hydrocarbons, and cobalt catalysts can mainly produce heavy hydrocarbons containing wax. Furthermore, iron catalysts can mainly produce alkenes and alkanes, and cobalt catalysts can mainly produce alkanes. Nickel catalysts are catalysts containing nickel as an active ingredient. Ruthenium catalysts are catalysts containing ruthenium as an active ingredient. Iron catalysts are catalysts containing iron as an active ingredient. Cobalt catalysts are catalysts containing cobalt as an active ingredient. The content of the active ingredient may be 20% by mass or more of the total catalyst.

[0023] The measuring unit 20 measures the temperature of the catalyst 15, which has been heated by the generation of hydrocarbons, at a plurality of measurement positions PO along the direction in which the raw materials flow. The measuring unit 20 may include a plurality of temperature sensors. For example, the measuring unit 20 may include a multi-point temperature sensor having a plurality of thermocouples. The measuring unit 20 can measure the temperature of the catalyst 15 at the plurality of measurement positions PO. In this embodiment, the plurality of measurement positions PO include measurement positions PO1 to PO5, and the temperature of the catalyst 15 is measured at each measurement position PO. Specifically, the measuring unit 20 measures the current temperature of the catalyst 15 at each of the measurement positions PO1 to PO5. However, the number of plurality of measurement positions PO measured by the measuring unit 20 is not particularly limited. The number of plurality of measurement positions PO may be, for example, 4 or more.

[0024] The input unit 30 receives the temperature of the catalyst 15, which has been heated by the generation of hydrocarbons, measured at multiple measurement positions PO along the direction in which the raw material flows. Specifically, the input unit 30 receives the temperatures of measurement positions PO1 to PO5, which have been measured at the measurement unit 20.

[0025] The controller 40 is a computer that includes a CPU (Central Processing Unit), memory, and an input / output unit. The controller 40 stores a program for determining the state of the catalyst 15 and data such as the temperatures of measurement positions PO1 to PO5 that are referenced during the execution of the program. The controller 40 then determines the state of the catalyst 15.

[0026] Catalyst 15 deteriorates over time due to sintering, carbon deposition, and catalyst poisoning, resulting in a decrease in the performance of catalyst 15. Sintering is a phenomenon in which the active metal particles in catalyst 15 aggregate when catalyst 15 is used at high temperatures, reducing the specific surface area of ​​the active metal and thus decreasing the performance of catalyst 15. Carbon deposition is a phenomenon in which hydrocarbons generated from raw materials containing carbon dioxide coat the surface of the active metal of catalyst 15, thereby decreasing the performance of catalyst 15. Catalyst poisoning is a phenomenon in which catalyst poisons, such as sulfur components contained in the raw materials, chemically react with the active metal, thereby decreasing the performance of catalyst 15.

[0027] Figure 4 is a graph showing the change in the temperature peak of catalyst 15 as it is heated by hydrocarbon generation. As shown in Figure 4, the reaction that generates hydrocarbons from raw materials containing carbon dioxide is an exothermic reaction, and the heat generated by the reaction causes the temperature of catalyst 15 to rise. The temperature peak of catalyst 15 is located upstream of catalyst 15 in year 0, when catalyst 15 is first put into use. This is thought to be because, at the start of use of catalyst 15, the reaction mainly occurs upstream of catalyst 15 where the concentration of reaction raw materials is high. On the other hand, the peak of catalyst 15 shifts downstream of catalyst 15 as the length of time catalyst 15 is used increases. This is thought to be because the performance of catalyst 15 on the upstream side deteriorates due to sintering, carbon deposition, and catalyst poisoning, and the region where the reaction mainly occurs shifts downstream.

[0028] Therefore, in the catalyst state determination device 1 according to this embodiment, the controller 40 determines the state of the catalyst 15 based on the relationship between multiple measurement positions PO and the temperature of the catalyst 15 measured at the multiple measurement positions PO. As described above, the peak temperature of the catalyst 15 shifts downstream of the catalyst 15 according to the usage time of the catalyst 15. Therefore, the state of the catalyst 15 can be determined from the relationship between the multiple measurement positions PO and the temperature of the catalyst 15.

[0029] Figure 5 is an explanatory diagram showing a method for calculating the replacement timing of catalyst 15. In Figure 5, the current temperature peak of catalyst 15 is shown as the first peak P1, the temperature peak at the start of use of catalyst 15 is shown as the second peak P2, and the temperature peak at the time of catalyst 15 replacement is shown as the third peak P3. In Figure 5, the current usage time of catalyst 15 is Tc, the time at the start of use of catalyst 15 is Ts=0, and the time at the time of catalyst 15 replacement is Te. Also in Figure 5, the peak top of the first peak P1 is shown as the first peak top PT1, the peak top of the second peak P2 is shown as the second peak top PT2, and the peak top of the third peak P3 is shown as the third peak top PT3. Also in Figure 5, the position at the first peak top PT1 is shown as the first peak top position Xc, the position at the second peak top PT2 is shown as the second peak top position Xs, and the position at the third peak top PT3 is shown as the third peak top position Xe. In this context, "peak top" refers to the point among the peaks where the temperature is highest. Furthermore, "peak top position" refers to the position of the catalyst 15 at the peak top in the direction of raw material flow.

[0030] Each peak can be derived from the current temperature of the catalyst 15 measured at multiple measurement positions PO by the measurement unit 20. Each peak top can be obtained by estimating the point where the temperature is highest among the peaks. The first peak top position Xc may be determined, for example, as the position where the temperature of the catalyst 15 reverses from an upward trend to a downward trend as one moves from the upstream to the downstream of the catalyst 15. Each peak top position can be obtained by determining the position of the peak top at each peak. The second peak P2 may be the temperature peak at the start of use of the catalyst 15 when the first peak P1 was measured. However, if the same or similar peak progression is observed, such as when using the same type of catalyst 15, the second peak P2 may be obtained by measuring a catalyst 15 from a different lot. Furthermore, the third peak P3 is the temperature peak at the time of catalyst 15 replacement and therefore cannot be measured at the current time. For this reason, the third peak P3 is the temperature peak at the time of catalyst 15 replacement, which has been previously measured using a catalyst 15 that shows the same or similar peak progression.

[0031] Here, the current remaining lifespan of catalyst 15 can be calculated using the following formula (1). Remaining life (%)=(Xe-Xc) / (Xe-Xs)×100 (1) In the above formula (1), Xc represents the first peak top position, Xs represents the second peak top position, and Xe represents the third peak top position. The remaining life of catalyst 15 is assumed to be 100% at the start of use and 0% at the time of catalyst replacement.

[0032] As can be seen from the above formula (1), the current remaining life of catalyst 15 can be determined based on the first peak top position Xc. Specifically, the current remaining life of catalyst 15 can be determined based on the first peak top position Xc, the second peak top position Xs, and the third peak top position Xe.

[0033] Thus, the controller 40 may estimate the first peak top position Xc in the current operating state, where the temperature of the catalyst 15 is at its maximum in the direction of the raw material flow, based on the relationship between the multiple measurement positions PO and the temperature of the catalyst 15 measured at each of the multiple measurement positions PO. The controller 40 may then determine the state of the catalyst 15 based on the first peak top position Xc.

[0034] Specifically, the controller 40 may determine the state of the catalyst 15 based on the relationship between the first peak top position Xc, the second peak top position Xs where the temperature of the catalyst 15 is at its maximum value when it is first put into use, and the third peak top position Xe where the temperature of the catalyst 15 is at its maximum value when it is time to replace the catalyst 15. In the above formula (1), the current remaining life of the catalyst 15 is determined using the first peak top position Xc, the second peak top position Xs, and the third peak top position Xe. However, if the first peak top position Xc is known, the current state of the catalyst 15 can be roughly understood. Therefore, the state of the catalyst 15 may be determined based only on the first peak top position Xc.

[0035] Furthermore, the replacement timing for catalyst 15 can be calculated using the following formula (2). Te=Tc+(Tc-Ts)×(Xe-Xc) / (Xc-Xs) (2) In the above formula (2), Te represents the replacement time (or time) of catalyst 15, Ts represents the time when catalyst 15 is first used, Tc represents the current usage time of catalyst 15, Xc represents the first peak top position, Xs represents the second peak top position, and Xe represents the third peak top position.

[0036] As can be seen from the above formula (2), the current replacement timing for catalyst 15 can be determined based on the first peak top position Xc. Specifically, the current replacement timing for catalyst 15 can be determined based on the first peak top position Xc, the second peak top position Xs, the third peak top position Xe, the current usage time of catalyst 15 Tc, the time Ts when catalyst 15 was first used, and the replacement timing Te of catalyst 15.

[0037] Thus, the controller 40 may determine the state of the catalyst 15 based on the first peak top position Xc and the usage time of the catalyst 15 from the second peak top position Xs to the first peak top position Xc. In addition, the controller 40 may determine the replacement time Te of the catalyst 15 based on the first peak top position Xc, similar to when the current remaining life of the catalyst 15 is determined.

[0038] The output unit 50 outputs data indicating the state of the catalyst 15 obtained by the controller 40. The output unit 50 may output at least one selected from the group consisting of the degradation state of the catalyst 15, the remaining lifespan, and the replacement time. The state of the catalyst 15 output from the output unit 50 may be displayed on a display device such as a monitor (not shown).

[0039] In this embodiment, the controller 40 estimates the first peak top PT1 of the first peak P1 and determines the state of the catalyst 15 based on the first peak top position Xc. However, the controller 40 may also determine that the catalyst 15 is degraded if a measurement position among the multiple measurement positions PO where the temperature is higher than a threshold is located downstream of a predetermined measurement position. Therefore, it is not always necessary to use the first peak top PT1.

[0040] Next, the procedure for determining the remaining lifespan of catalyst 15 will be explained using the flowchart in Figure 6.

[0041] In step S1, the controller 40 acquires the temperature of the catalyst 15, which is measured at multiple measurement positions by the measurement unit 20 and input via the input unit 30.

[0042] In step S2, the controller 40 estimates, for example, the first peak top position Xc. In addition to the first peak top position Xc, the controller 40 may also estimate the second peak top position Xs.

[0043] In step S3, the controller 40 determines the state of the catalyst 15 based on the first peak top position Xc. The controller 40 determines the remaining lifespan of the catalyst 15 based on, for example, the first peak top position Xc, the second peak top position Xs, and the third peak top position Xe. Specifically, the controller 40 determines the remaining lifespan of the catalyst 15 based on the above formula (1).

[0044] Next, the procedure for determining when to replace catalyst 15 will be explained using the flowchart in Figure 7.

[0045] First, as described above, the controller 40 acquires the temperature in step S1 and estimates the peak top position in step S2.

[0046] In step S4, the controller 40 determines the state of the catalyst 15 based on the first peak top position Xc. The controller 40 determines the timing for replacing the catalyst 15 based, for example, on the first peak top position Xc and the usage time of the catalyst 15. Specifically, the controller 40 determines the timing for replacing the catalyst 15 based on the above formula (2).

[0047] In this embodiment, a method was described for the controller 40 to determine the remaining lifespan of the catalyst 15 and the timing of its replacement. However, the degradation state of the catalyst 15 may also be determined based on the first peak top position Xc of the catalyst 15, using an indicator of degradation status such as the degree of degradation or the progression of degradation. Therefore, the state of the catalyst 15 may include at least one selected from the group consisting of the degradation state of the catalyst 15, the remaining lifespan, and the timing of its replacement.

[0048] Next, the operation and effects of the catalyst state determination device 1 according to this embodiment will be described.

[0049] The catalyst state determination method involves measuring the temperature of the catalyst 15, which is heated by the generation of hydrocarbons, at multiple measurement positions PO along the direction of the flow of the raw materials in a reactor 12 that generates hydrocarbons by bringing raw materials containing carbon dioxide and hydrogen into contact with the catalyst 15. The catalyst state determination method determines the state of the catalyst 15 based on the relationship between the multiple measurement positions PO and the temperatures of the catalyst 15 measured at the multiple measurement positions PO.

[0050] The catalyst state determination device 1 is located in a reactor 12 that generates hydrocarbons by bringing a raw material containing carbon dioxide and hydrogen into contact with a catalyst 15. The device includes an input unit 30 to which the temperature of the catalyst 15, which has been heated by the generation of hydrocarbons and measured at multiple measurement positions PO along the direction in which the raw material flows, is input. The catalyst state determination device 1 also includes a controller 40 that determines the state of the catalyst 15 based on the relationship between the multiple measurement positions PO and the temperature of the catalyst 15 measured at the multiple measurement positions PO.

[0051] The temperature peak of the catalyst 15 shifts along the direction of the raw material flow as the catalyst 15 is used over time. Therefore, the controller 40 can determine the state of the catalyst 15 based on the temperatures measured at multiple measurement locations along the direction of the raw material flow. Thus, the catalyst state determination method and catalyst state determination device 1 can determine the future state of the catalyst.

[0052] For example, even if the catalyst 15 has a set replacement cycle of 2 years, the actual degradation state of the catalyst 15 will vary depending on how the catalyst 15 is used, so it will not necessarily reach the end of its lifespan in 2 years. However, according to the catalyst state determination method and catalyst state determination device 1 of this embodiment, it is possible to determine the future state of the catalyst, and therefore, depending on the state of the catalyst 15, it is possible to use the catalyst 15 beyond the replacement period.

[0053] The state of the catalyst 15 may include at least one selected from the group consisting of the degradation state of the catalyst 15, the remaining lifespan, and the replacement timing. With this configuration, the degradation state, remaining lifespan, and replacement timing can be determined, allowing for efficient use of the catalyst 15 and reducing the operating costs of the catalyst 15.

[0054] The controller 40 may estimate the first peak top position Xc in the current operating state, where the temperature of the catalyst 15 is at its maximum in the direction of raw material flow, based on the relationship between multiple measurement positions PO and the temperature of the catalyst 15 measured at each of the multiple measurement positions PO. The controller may then determine the state of the catalyst 15 based on the first peak top position Xc. By estimating the first peak top position Xc and determining the state of the catalyst 15 based on the position of the first peak top position Xc, the current state of the catalyst 15 can be grasped more accurately.

[0055] The state of the catalyst 15 may be determined based on the relationship between the first peak top position Xc, the second peak top position Xs where the temperature of the catalyst 15 is at its maximum value at the start of use, and the third peak top position Xe where the temperature of the catalyst 15 is at its maximum value when it is time to replace the catalyst 15. This configuration allows for a more accurate determination of the state of the catalyst 15, such as its remaining lifespan. As a result, the catalyst 15 can be used more efficiently, and a further reduction in the operating costs of the catalyst 15 can be expected.

[0056] The state of the catalyst 15 may be determined based on the first peak top position Xc and the usage time of the catalyst 15 from the second peak top position Xs to the first peak top position Xc. This configuration allows for more accurate determination of the state of the catalyst 15, such as when it is time to replace it. As a result, the catalyst 15 can be used more efficiently, and a further reduction in the operating costs of the catalyst 15 can be expected.

[0057] Although several embodiments have been described, it is possible to modify or transform the embodiments based on the above disclosure. All components of the above embodiments, and all features described in the claims, may be taken individually and combined, provided that they do not conflict with each other.

[0058] This disclosure can contribute, for example, to United Nations Sustainable Development Goal (SDG) 13, "Take urgent action to combat climate change and its impacts." [Explanation of Symbols]

[0059] 1. Catalyst state determination device 12 Reactors 15 Catalyst 20 Measuring part 30 Input section 40 controllers PO measurement position Xc First peak top position Xs Second Peak Top Position Xe's third peak top position

Claims

1. In a reactor that produces hydrocarbons by contacting a catalyst with raw materials containing carbon dioxide and hydrogen, the temperature of the catalyst, which is heated by the production of the hydrocarbons, is measured at multiple measurement positions along the direction in which the raw materials flow. A catalyst state determination method for determining the state of a catalyst based on the relationship between the plurality of measurement positions and the temperature of the catalyst measured at the plurality of measurement positions.

2. The catalyst state determination method according to claim 1, wherein the catalyst state includes at least one selected from the group consisting of the catalyst degradation state, remaining lifespan, and replacement time.

3. Based on the relationship between the plurality of measurement positions and the temperature of the catalyst measured at each of the plurality of measurement positions, the first peak top position in the current operating state where the temperature of the catalyst is at its maximum in the direction in which the raw material flows is estimated. A catalyst state determination method according to claim 1 or 2, wherein the state of the catalyst is determined based on the first peak top position.

4. The catalyst state determination method according to claim 3, wherein the state of the catalyst is determined based on the relationship between the first peak top position, the second peak top position where the temperature of the catalyst at the start of use is at its maximum value, and the third peak top position where the temperature of the catalyst at the time of replacement is at its maximum value.

5. The catalyst state determination method according to claim 4, wherein the state of the catalyst is determined based on the first peak top position and the usage time of the catalyst from the second peak top position to the first peak top position.

6. In a reactor that produces hydrocarbons by contacting a catalyst with raw materials containing carbon dioxide and hydrogen, an input unit is provided to which the temperature of the catalyst, heated by the production of hydrocarbons, is input, and which is measured at multiple measurement positions along the direction in which the raw materials flow. A controller that determines the state of the catalyst based on the relationship between the plurality of measurement positions and the temperature of the catalyst measured at the plurality of measurement positions, A catalyst state determination device equipped with the following features.

Images