Catalyst degradation estimation method, catalyst degradation estimation apparatus, and program
By calculating catalyst physical properties using a recurrence formula based on reaction time and temperature, the method accurately predicts catalyst degradation, addressing inaccuracies in existing methods that fail to account for temperature changes.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- RESONAC CORP
- Filing Date
- 2021-12-24
- Publication Date
- 2026-05-19
AI Technical Summary
Existing methods for estimating catalyst degradation in plants fail to accurately account for temperature changes over time, leading to inaccuracies in predicting catalyst deterioration.
A method and device that estimate catalyst degradation by calculating physical properties such as metal dispersion, specific surface area, and particle size using a recurrence formula based on reaction time and temperature, incorporating constants and activation energy to handle temperature fluctuations.
Improves the accuracy of catalyst degradation estimation by reflecting temperature changes, allowing for more precise prediction of catalyst deterioration.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a catalyst deterioration estimation method, a catalyst deterioration estimation device, and a program.
Background Art
[0002] Conventionally, catalysts have been used in various applications. For example, a catalyst is used to improve the yield and performance when producing a compound in a plant. The catalyst gradually deteriorates due to an increase in temperature and changes over time. Therefore, it is important to estimate the degree of catalyst deterioration in order to maintain the long-term operation of the plant.
[0003] As a method for estimating the degree of catalyst deterioration, the following equation of nth-order kinetics for obtaining the loss of the specific surface area of the catalyst is known (Non-Patent Document 1).
[0004]
Equation
[0005] S(t): Specific surface area at reaction time t S(0): Specific surface area at the time point of reaction time 0 hours n, b: Constants
Prior Art Documents
Non-Patent Documents
[0006]
Non-Patent Document 1
[0008] Therefore,
[0009]
number
[0010] So,
[0011]
number
[0012] k: constant E a Activation energy of catalyst degradation R: gaseous state T(t): Reaction temperature (K) at reaction time t This is the result.
[0013] However, in equation B above, a contradiction arises: when the temperature is lowered compared to the previous time, the specific surface area of the catalyst increases despite the catalyst degrading over time. Also, while it would be ideal to refer to past literature values for the activation energy of sintering used here, this is not always possible.
[0014] The present invention aims to improve the accuracy of estimating the degree of catalyst degradation. [Means for solving the problem]
[0015] [1] A method executed by a computer, comprising: successively estimating the degree of deterioration of the catalyst by calculating physical property values of the catalyst from the reaction time and reaction temperature of a chemical reaction as a recurrence formula of time. The method according to [1], wherein the physical property values of the catalyst include at least one of the metal dispersion degree of the catalyst, the specific surface area of the catalyst, and the particle size of the catalyst. [2] The method according to [1], wherein the physical property value of the catalyst is the metal dispersion degree of the catalyst. The physical property value of the catalyst is The physical property value of the catalyst is
[0016] [Number]
[0017] D(t i ): Metal dispersion degree at reaction time t i D(t i-1 ): Metal dispersion degree at reaction time t i-1 n, k: Constants E a : Activation energy of sintering R: Gas constant T(t i ): Reaction temperature (K) at reaction time t i The method according to [1] or [2], calculated using [4] The method according to [1], wherein the physical property value of the catalyst is the specific surface area of the catalyst. The physical property value of the catalyst is
[0018] [Number]
[0019] S(t i ): Specific surface area at reaction time t i S(t i-1 ): Specific surface area at reaction time t i-1 n, k: Constants E aActivation energy of sintering R: Gas state T(t i ): Reaction time t i Reaction temperature (K) The method described in [1] or [2], which is calculated using [1] or [2]. [5] The physical property value of the catalyst is the particle size of the catalyst, The physical properties of the catalyst are as follows:
[0020]
number
[0021] r(t i ): Reaction time t i Particle size r(t i-1 ): Reaction time t i-1 Particle size n,k: constant E a Activation energy of sintering R: Gas state T(t i ): Reaction time t i Reaction temperature (K) The method described in [1] or [2], which is calculated using [1] or [2]. [6] The method according to any one of [3] to [5], wherein the constants n and k are determined by the least squares method. [7] The method according to any one of [1] to [6], wherein the reaction temperature is the temperature of the raw materials introduced into the reactor in which the chemical reaction is carried out. [8] The method according to any one of [1] to [7], wherein the catalyst is a substance that promotes a chemical reaction in the production of a compound. [9] A catalyst degradation estimation device comprising an estimation unit configured to sequentially estimate the degree of catalyst degradation by calculating the physical properties of the catalyst from the reaction time and reaction temperature of a chemical reaction using a recurrence relation over time.
[10] Computers, A program that functions as an estimation unit that sequentially estimates the degree of catalyst degradation by calculating the physical properties of the catalyst from the reaction time and reaction temperature of a chemical reaction using a time recurrence relation. [Effects of the Invention]
[0022] According to the present invention, the accuracy of estimating the degree of catalyst degradation can be improved. [Brief explanation of the drawing]
[0023] [Figure 1] This is an overall configuration diagram of one embodiment of the present invention. [Figure 2] This is a hardware configuration diagram of a catalyst degradation estimation device according to one embodiment of the present invention. [Figure 3] This is a functional block diagram of a catalyst degradation estimation device according to one embodiment of the present invention. [Figure 4] This is a flowchart showing the parameter determination process related to one embodiment of the present invention. [Figure 5] This is a flowchart showing the catalyst degradation estimation process according to one embodiment of the present invention. [Figure 6] This figure compares the calculation of metal dispersion according to one embodiment of the present invention with the calculation of metal dispersion using the conventional technology. [Figure 7] This figure shows a comparison of the degree of metal dispersion when the temperature changes and when the temperature is constant, according to one embodiment of the present invention. [Modes for carrying out the invention]
[0024] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant descriptions will be omitted.
[0025] <Overall structure> Figure 1 is an overall configuration diagram of one embodiment of the present invention. The catalyst degradation estimation device 10 is operated by an operator 20.
[0026] The catalyst degradation estimation device 10 is a device for estimating the degree of catalyst degradation. The catalyst degradation estimation device 10 consists of one or more computers (for example, a personal computer operated by operator 20, or a personal computer operated by operator 20 and a server). The catalyst degradation estimation device 10 will be described in detail later with reference to Figures 2 and 3.
[0027] <Hardware Configuration> Figure 2 is a hardware configuration diagram of a catalyst degradation estimation device 10 according to one embodiment of the present invention. The catalyst degradation estimation device 10 has a CPU (Central Processing Unit) 1, a ROM (Read Only Memory) 2, and a RAM (Random Access Memory) 3. The CPU 1, ROM 2, and RAM 3 form a so-called computer. The catalyst degradation estimation device 10 may also have an auxiliary storage device 4, a display device 5, an operating device 6, an I / F (Interface) device 7, and a drive device 8. The hardware components of the catalyst degradation estimation device 10 are interconnected via a bus B.
[0028] CPU1 is a computing device that executes various programs installed on auxiliary storage device 4.
[0029] ROM2 is non-volatile memory. ROM2 functions as a main memory device that stores various programs, data, etc., necessary for the CPU1 to execute the various programs installed on the auxiliary storage device 4. Specifically, ROM2 functions as a main memory device that stores boot programs such as BIOS (Basic Input / Output System) and EFI (Extensible Firmware Interface).
[0030] RAM3 is a volatile memory such as DRAM (Dynamic Random Access Memory) or SRAM (Static Random Access Memory). RAM3 functions as a main memory device that provides a working area that is expanded when various programs installed on auxiliary storage device 4 are executed by CPU 1.
[0031] The auxiliary storage device 4 is an auxiliary storage device that stores various programs and information used when various programs are executed.
[0032] Display device 5 is a display device that displays the internal state of the catalyst degradation estimation device 10, etc.
[0033] The operating device 6 is an input device in which the manager of the catalyst degradation estimation device 10 inputs various instructions to the catalyst degradation estimation device 10.
[0034] The I / F device 7 is a communication device that connects to a network and communicates with other devices.
[0035] The drive device 8 is a device for setting the storage medium 9. The storage medium 9 here includes media that record information optically, electrically, or magnetically, such as CD-ROMs, flexible disks, and magneto-optical disks. The storage medium 9 may also include semiconductor memories that record information electrically, such as EPROMs (Erasable Programmable Read Only Memory) and flash memory.
[0036] The various programs to be installed on the auxiliary storage device 4 are installed, for example, when the distributed storage medium 9 is set in the drive device 8 and the various programs recorded on the storage medium 9 are read by the drive device 8. Alternatively, the various programs to be installed on the auxiliary storage device 4 may be installed by downloading them from the network via the I / F device 7.
[0037] <Function Block> Figure 3 is a functional block diagram of a catalyst degradation estimation device 10 according to one embodiment of the present invention. The catalyst degradation estimation device 10 may include an acquisition unit 101, an estimation unit 102, an output unit 103, and a parameter determination unit 104. Furthermore, the catalyst degradation estimation device 10 can function as the acquisition unit 101, estimation unit 102, output unit 103, and parameter determination unit 104 by executing a program.
[0038] The acquisition unit 101 acquires information necessary to estimate the degree of catalyst degradation. Below are the reaction time and reaction temperature, and the parameters n, k and the sintering activation energy E. a I will explain it in separate sections.
[0039] <<Reaction time and reaction temperature>> The acquisition unit 101 acquires the reaction time and reaction temperature of the chemical reaction. Specifically, the acquisition unit 101 acquires the reaction time and the reaction temperature at that reaction time. The reaction time and reaction temperature will be described in detail below.
[0040] "Reaction time" refers to the time elapsed since the start of a chemical reaction.
[0041] "Reaction temperature" refers to the reaction temperature at each reaction time. For example, the reaction temperature is the temperature of the catalyst surface where the chemical reaction takes place, or, if the reaction temperature is controlled by the temperature of the raw materials introduced into the reactor, the temperature of the introduced raw materials may be used as the reaction temperature. Furthermore, the reactor is, for example, a reactor in which reaction tubes are arranged inside and raw materials are introduced from the top or bottom, but is not limited to this.
[0042] Thus, in one embodiment of the present invention, since the reaction time and the reaction temperature during that reaction time are used, the degree of catalyst degradation, which changes by controlling the temperature, can be estimated.
[0043] <<Parameters n, k and sintering activation energy E a>> The acquisition unit 101 acquires the parameters n, k and the sintering activation energy E a The acquisition unit 101 obtains the parameters n, k and the sintering activation energy E determined by the parameter determination unit 104. a Obtain the following parameters n, k and the sintering activation energy E. a I will explain this in detail.
[0044] "n,k" are values used in the calculation of the catalyst's physical properties using the following equations (1) to (3).
[0045] "Activation energy of sintering E a This value is used in the calculation of the catalyst's physical properties using the following equations (1) to (3).
[0046] The estimation unit 102 sequentially estimates the degree of catalyst degradation by calculating the physical properties of the catalyst from the reaction time and reaction temperature of the chemical reaction using a time recurrence relation.
[0047] Here, we will explain the physical properties of catalysts. For example, a catalyst is a substance that accelerates chemical reactions in the production of compounds. For instance, the physical properties of a catalyst include at least one of the following: the degree of metal dispersion of the catalyst, the specific surface area of the catalyst, and the particle size of the catalyst. The following will explain this in three parts: <<Calculation of the degree of metal dispersion of the catalyst>>, <<Calculation of the specific surface area of the catalyst>>, and <<Calculation of the particle size of the catalyst>>.
[0048] <<Calculation of the degree of metal dispersion in the catalyst>> The "metal dispersion of a catalyst" is a value that indicates how much of the metal contained in a metal-supported catalyst, such as a precious metal, contributes to the surface, and can be measured by a pulse measurement method utilizing chemiadsorption. More specifically, the metal dispersion can be calculated by pulse measurement using a gas (such as CO or H2) that selectively chemiadsorbs onto the metal surface. As the catalyst deteriorates, the metal dispersion decreases.
[0049] The estimation unit 102 is,
[0050]
number
[0051] D(t i ): Reaction time t i Degree of metal dispersion D(t i-1 ): Reaction time t i-1 Degree of metal dispersion n,k: constant E a Activation energy of sintering R: Gas state T(t i ): Reaction time t i Reaction temperature (K) The degree of metal dispersion of the catalyst can be calculated using this method.
[0052] <<Calculation of Specific Surface Area of Catalyst>> The "specific surface area of a catalyst" is the surface area per unit mass or per unit volume of the catalyst. For example, the BET specific surface area can be calculated based on the BET theory by cooling a sample to liquid nitrogen temperature under a helium-diluted nitrogen gas flow, then returning it to room temperature and measuring the amount of nitrogen desorbed. As the catalyst degrades, the specific surface area decreases.
[0053] The estimation unit 102 is,
[0054]
number
[0055] <<Calculation of catalyst particle size>> "Catalyst particle size" is the average diameter of each catalyst particle, assuming each particle is a perfect sphere. It can be measured by direct observation of particles using a transmission electron microscope (TEM), crystallite size distribution measurement using X-ray diffraction (XRD), or particle size distribution measurement using small-angle X-ray scattering (SAXS). As the catalyst degrades, the particle size increases.
[0056] The estimation unit 102 is,
[0057]
number
[0058] In this way, the estimation unit 102 sequentially estimates the degree of catalyst degradation by calculating the physical properties of the catalyst at each time point (that is, it sequentially estimates the degree of catalyst degradation at t=0,...,i-1,i,i+1,...).
[0059] In one embodiment of the present invention, time recurrence relations such as Equations 1 to 3 are used (that is, the physical properties of the catalyst at a certain time are calculated using the physical properties of the catalyst at a time earlier than that time). Since Equations 1 to 3 reflect past thermal history, they can also handle temperature changes in the plant.
[0060] The output unit 103 outputs the degree of catalyst degradation estimated by the estimation unit 102. For example, the output unit 103 displays the degree of catalyst degradation on the display device 5 of the catalyst degradation estimation device 10.
[0061] The parameter determination unit 104 determines the parameters n, k and the sintering activation energy E a To decide.
[0062] <Method> The parameter determination process will be explained below with reference to Figure 4, and the catalyst degradation estimation process will be explained with reference to Figure 5.
[0063] <<Parameter determination process>> Figure 4 is a flowchart showing the parameter determination process according to one embodiment of the present invention.
[0064] In step 201 (S201), the catalyst degradation estimation device 10 (parameter determination unit 104) acquires experimental data. Specifically, the catalyst degradation estimation device 10 (parameter determination unit 104) acquires experimental data of the reaction time, the reaction temperature during the reaction time, and the physical properties of the catalyst during the reaction time.
[0065] In step 202 (S202), the catalyst degradation estimation device 10 (parameter determination unit 104) obtains an appropriate value that will be a candidate for the activation energy.
[0066] In step 203 (S203), the catalyst degradation estimation device 10 (parameter determination unit 104) determines the reaction time t used to calculate the physical properties of the catalyst. i and reaction temperature T(t i ) obtain.
[0067] In step 204 (S204), the catalyst degradation estimation device 10 (parameter determination unit 104) calculates the physical properties of the catalyst from the reaction time and reaction temperature obtained in S203 using a time recurrence relation (for example, equations 1 to 3).
[0068] In step 205 (S205), the catalyst degradation estimation device 10 (parameter determination unit 104) determines whether the calculation of the catalyst's physical properties for all reaction times has been completed. If the calculation of the catalyst's physical properties for all reaction times has been completed, the process proceeds to step 206. If the calculation of the catalyst's physical properties for all reaction times has not been completed, the process returns to step 203 to obtain the next reaction time and reaction temperature.
[0069] In step 206 (S206), the catalyst degradation estimation device 10 (parameter determination unit 104) determines the values of n and k by the least squares method using experimental data and the physical properties of the catalyst calculated in S203 to S205. For example, the calculation is performed with constraints so that n is a value between 1 and 15.
[0070] In step 207 (S207), the catalyst degradation estimation device 10 (parameter determination unit 104) stores the values of n and k and the sum of squared errors determined in S206.
[0071] In step 208 (S208), the catalyst degradation estimation device 10 (parameter determination unit 104) determines whether the calculation of n and k for all candidate activation energies has been completed. If the calculation of the constants n and k for all candidate activation energies has been completed, the device proceeds to step 209. If the calculation of the constants n and k for all candidate activation energies has not been completed, the device returns to step 202 to obtain the next candidate activation energies.
[0072] In step 209 (S209), the catalyst degradation estimation device 10 (parameter determination unit 104) determines the activation energy value, the value of n, and the value of k as parameters, which are the values when the sum of squared errors is smallest.
[0073] <<Catalyst Degradation Estimation Process>> Figure 5 is a flowchart showing the catalyst degradation estimation process according to one embodiment of the present invention.
[0074] In step 101 (S101), the catalyst degradation estimation device 10 (acquisition unit 101) calculates the parameters n, k and the sintering activation energy E a Obtain the value (for example, the value determined in Figure 4).
[0075] In step 102 (S102), the catalyst degradation estimation device 10 (acquisition unit 101) calculates the reaction time t of the chemical reaction. i and reaction temperature T(t i ) obtain.
[0076] In step 103 (S103), the catalyst degradation estimation device 10 (estimation unit 102) uses the parameter values obtained in S101 to calculate the physical properties of the catalyst from the reaction time and reaction temperature obtained in S102 using a time recurrence relation.
[0077] In step 104 (S104), the catalyst degradation estimation device 10 (estimation unit 102) determines whether the calculation of the catalyst's physical properties for all reaction times has been completed. If the calculation of the catalyst's physical properties for all reaction times has been completed, the process proceeds to step 105. If the calculation of the catalyst's physical properties for all reaction times has not been completed, the process returns to step 102 to obtain the next reaction time and reaction temperature.
[0078] Thus, in steps S102 to S104, the catalyst degradation estimation device 10 (estimation unit 102) sequentially estimates the degree of catalyst degradation by calculating the physical properties of the catalyst at each time point.
[0079] In step 105 (S105), the catalyst degradation estimation device 10 (output unit 103) outputs the degree of catalyst degradation estimated in S102 to S104.
[0080] Figure 6 is a diagram for comparing the calculation of metal dispersion according to one embodiment of the present invention with the calculation of metal dispersion using the conventional technology.
[0081] The broken line labeled "Temperature (K)" shows the reaction temperature at each reaction time.
[0082] The curve for "Relative Metallic Dispersion (D / D0) - This Invention" shows the relative metallic dispersion calculated by the formula of one embodiment of the present invention (specifically, formula 1 below).
[0083]
number
[0084] n=5.82, k=1.66×10 9 ,E a = 100 kJ / mol.
[0085] The curve labeled "Relative Metallic Dispersion (D / D0) - Conventional Technology" shows the relative metallic dispersion calculated using the conventional technology formula (specifically, formula A below).
[0086]
number
[0087] n=5.82 and b=0.564 were used. Note that the temperature changes shown in Figure 6 are obtained.
[0088]
number
[0089] From the average value, we derived b = 0.564.
[0090] Figure 6 shows that catalyst degradation is suppressed while the reaction temperature in [1] is being lowered. On the other hand, while the reaction temperature in [2] is being raised, catalyst degradation is rapidly progressing. The conventional formula shows that the catalyst is degrading exponentially, but it cannot express the detailed nature of the degradation.
[0091] Figure 7 is a diagram for comparing the relative metal dispersion when the temperature changes and when the temperature is constant, according to one embodiment of the present invention.
[0092] The broken line for "Temperature (K)" and the straight line for "493 (K)" show the reaction temperature at each reaction time. The broken line for "Temperature (K)" represents the case where the temperature changes, and the straight line for "493 (K)" represents the case where the temperature is constant. The curve for "Relative Metallic Dispersion (D / D0)_(Temperature Change)" shows the relative metallic dispersion (calculated using Equation 1) when the temperature changes, and the curve for "Relative Metallic Dispersion (D / D0)_493K" shows the relative metallic dispersion (calculated using Equation 1) when the temperature is constant. Note that n=5.82, k=1.66×10 9 ,E a = 100 kJ / mol.
[0093] The comparison results in Figure 7 show that when the temperature changes, the catalyst degrades more slowly than when the temperature is constant, especially when the reaction temperature is below 493K. On the other hand, when the reaction temperature is further increased above 493K, the catalyst degrades more rapidly than when the temperature is constant, and the degradation is also accelerated.
[0094] <Effects> Thus, in one embodiment of the present invention, it is possible to predict the degradation curve corresponding to temperature changes, and it is possible to see that degradation is suppressed during periods when the temperature is decreasing, while degradation is accelerated during periods when the temperature is rapidly increasing.
[0095] Although embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments described above, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims. [Explanation of symbols]
[0096] 1 CPU 2 ROM 3 RAM 4 Auxiliary storage 5 Display device 6 Operating device 7 I / F device 8 Drive unit 9 Storage medium 10. Catalyst Degradation Estimation Device 20 Operator 101 Acquisition Department 102 Estimation part 103 Output section 104 Parameter Determination Unit
Claims
1. A method by which a computer performs an action. A method comprising sequentially estimating the degree of degradation of a catalyst by calculating the degree of metal dispersion of the catalyst or the specific surface area of the catalyst using a recurrence relation over time, based on the reaction time and reaction temperature of a chemical reaction.
2. The degree of metal dispersion of the catalyst is [Math 1] D(t ｉ ): Reaction time t ｉ Metal dispersion in D(t ｉ-1 ): Reaction time t ｉ-1 Metal dispersion in n, k: constant E ａ Activation energy of sintering R: Number of gaseous states T(t ｉ ): Reaction time t ｉ Reaction temperature (K) The method according to claim 1, calculated using
3. The specific surface area of the catalyst is [Math 2] S(t ｉ ): Specific surface area at reaction time t ｉ S(t ｉ-1 ): Reaction time t ｉ-1 specific surface area n, k: constant E ａ Activation energy of sintering R: Number of gaseous states T(t ｉ ): Reaction time t ｉ Reaction temperature (K) The method according to claim 1, calculated using
4. The method according to claim 2 or 3, wherein the constants n and k are determined using the least squares method.
5. The method according to any one of claims 1 to 4, wherein the reaction temperature is the temperature of the raw materials introduced into the reactor in which the chemical reaction is carried out.
6. The method according to any one of claims 1 to 5, wherein the catalyst is a substance that promotes a chemical reaction in the production of a compound.
7. A catalyst degradation estimation device comprising an estimation unit configured to sequentially estimate the degree of catalyst degradation by calculating the degree of metal dispersion of the catalyst or the specific surface area of the catalyst from the reaction time and reaction temperature of a chemical reaction using a recurrence relation over time.
8. Computers, A program that functions as an estimation unit that sequentially estimates the degree of catalyst degradation by calculating the degree of metal dispersion of the catalyst or the specific surface area of the catalyst using a recurrence relation over time, based on the reaction time and reaction temperature of a chemical reaction.