Quality determination method
The quality determination method for honeycomb catalysts involves polishing the catalyst's inner surface, recovering and analyzing the polishing powder, and determining the catalyst's quality without destruction, addressing the limitations of current methods by enabling high-precision and efficient quality assessment.
Patent Information
- Application Number
- JP2023202142
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-11-29
- Publication Date
- 2025-06-10
AI Technical Summary
Current methods for determining the quality of honeycomb catalysts require destroying the catalyst, making it impossible to inspect all catalysts and risking the overlook of poor quality catalysts.
A quality determination method that polishes the inner surface of the catalyst's through holes using an abrasive, recovers the polishing powder, analyzes its component concentration, and determines the catalyst's quality without destroying it.
Enables high-precision quality determination of catalysts without destruction, allowing for efficient and accurate assessment of catalyst quality.
Smart Images
Figure 2025087464000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a quality determination method.
Background Art
[0002] Conventionally, a catalyst having a honeycomb structure used for purifying exhaust gas is regenerated to recover its performance against performance degradation during use, and a technique for determining the quality of the honeycomb catalyst after regeneration is known. Patent Document 1 is cited as an example of this type of technique. In Patent Document 1, it is described that the deterioration of the honeycomb catalyst is evaluated by measuring the thickness of a coating layer containing particles having a particle size of 2 μm or less deposited on the surface of the honeycomb catalyst.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] By the way, when determining the quality of a catalyst with higher precision using surface observation with a microscope or the like and component analysis, etc., in order to obtain a sample from inside the through-holes of the catalyst, it is necessary to destroy the catalyst, and it is not possible to inspect all of the catalysts, and there is a risk of overlooking poor quality of the catalyst.
[0005] An object of the present invention is to provide a quality determination method capable of determining the quality of a catalyst with high precision without destroying the catalyst.
Means for Solving the Problems
[0006] (1) The quality determination method according to the present invention is a quality determination method in a catalyst polishing method for polishing the inner surface of through holes of a catalyst by flowing an abrasive through the through holes, the method including: a polishing step of flowing the abrasive through the through holes to polish the inner surface; a recovery step of recovering polishing powder generated by the polishing step; an analysis step of analyzing the polishing powder recovered in the recovery step; and a quality determination step of determining the quality of the catalyst based on the component concentration derived in the analysis step.
[0007] (1) The quality determination method can determine the quality of the catalyst with high precision without destroying the catalyst.
[0008] (2) In the quality determination method according to (1), the catalyst is a denitration catalyst, and in the quality determination step, the quality of the catalyst is determined based on the related information in which the component concentration of the polishing powder and the denitration rate are associated.
[0009] (2) The quality determination method can efficiently determine the quality of the catalyst with high precision without destroying the catalyst.
[0010] (3) In the quality determination method according to (1) or (2), the abrasive is white alumina, and in the analysis step, at least one of the component concentrations of Ti and S in the catalyst is measured by analysis, and in the quality determination step, the quality of the catalyst is determined based on at least one of the component concentrations of Ti and S measured in the analysis step.
[0011] (3) The quality determination method can simply determine the quality of the catalyst with high precision without destroying the catalyst.
[0012] (4) In the quality determination method according to (3), in the quality determination step, when the pass determination criterion for the quality of the catalyst is that the denitration rate is 74.0% or more, if at least one of the component concentration of Ti in terms of TiO 2 conversion is 82.0% or more and the component concentration of S in terms of SO 3 conversion is 2.0% or less, the quality of the catalyst is determined to be qualified.
[0013] The quality determination method of (4) can determine the quality of the catalyst more simply and with high precision without destroying the catalyst.
[0014] In the quality determination method of (5), (1) or (2), the abrasive is steel grit. In the analysis step, the concentration of at least one of Ti, Al, and S in the catalyst is measured by analysis. In the quality determination step, the quality of the catalyst is determined based on the concentration of at least one of Ti, Al, and S measured in the analysis step.
[0015] The quality determination method of (5) can determine the quality of the catalyst simply and with high precision without destroying the catalyst.
[0016] In the quality determination method of (6), (5), when the pass determination criterion for the quality of the catalyst is that the denitration rate is 74.0% or more, the TiO of Ti measured in the analysis step 2 The component concentration in terms of conversion is 81.9% or more, and the Al of Al 2 O 3 When the component concentration in terms of conversion is 1.0% or less, and at least one of the component concentrations of S in terms of SO 3 In the case of conversion being 2.0% or less, the quality of the catalyst is determined to be qualified.
[0017] The quality determination method of (6) can determine the quality of the catalyst more simply and with high precision without destroying the catalyst.
[0018] In the quality determination method of (7), (1) or (2), the abrasive is green silicon carbide. In the analysis step, the concentration of at least one of Ti, Al, and S in the catalyst is measured by analysis. In the quality determination step, the quality of the catalyst is determined based on the concentration of at least one of Ti, Al, and S measured in the analysis step.
[0019] The quality determination method of (7) can determine the quality of the catalyst simply and with high precision without destroying the catalyst.
[0020] (8)(7) In the quality determination method described above, in the quality determination step, when the pass standard for the quality of the catalyst is that the denitration rate is 74.0% or more, the TiO of Ti measured in the analysis step 2 The component concentration in terms of conversion is 85.5% or more, and the Al of Al 2 O 3 When the component concentration in terms of conversion is 1.0% or less and at least one of the component concentrations of S in terms of SO 3 is 2.0% or less, the quality of the catalyst is determined to be qualified.
[0021] (8) The quality determination method can more simply and accurately determine the quality of the catalyst without destroying the catalyst.
[0022] (9) In the quality determination method described in at least one of (1) to (8) above, in the recovery step, after classifying the abrasive material that has undergone the polishing step, the polishing powder is recovered.
[0023] (9) The quality determination method can more efficiently and accurately determine the quality of the catalyst without destroying the catalyst.
[0024] (10) In the quality determination method described in at least one of (1) to (9) above, in the analysis step, the component concentration of the polishing powder recovered in the recovery step is analyzed by an X-ray analyzer.
[0025] (10) The quality determination method can more accurately determine the quality of the catalyst without destroying the catalyst.
Brief Description of the Drawings
[0026]
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Embodiments for Carrying Out the Invention
[0027] <Catalyst Polishing Device> Hereinafter, the catalyst polishing apparatus 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. As shown in FIGS. 1 and 2, the catalyst polishing apparatus 1 according to this embodiment is an apparatus that circulates abrasive A together with air through the through-holes C1 of the honeycomb catalyst C as a catalyst to polish and regenerate the inner surface C1a of the through-holes C1. The catalyst polishing apparatus is not limited to polishing for regenerating a used catalyst. For example, the catalyst polishing apparatus may polish to obtain a sample for determining the catalyst quality of an unused catalyst and confirming the performance of the catalyst, or may polish to obtain a sample for determining the catalyst quality of a catalyst during use and considering the timing of catalyst replacement. Examples of the form of the catalyst include known plate-shaped catalysts, lattice-shaped catalysts, corrugated catalysts, and the like. Any of the plate-shaped catalyst, lattice-shaped catalyst, and corrugated catalyst has through-holes penetrating in the exhaust gas flow direction. In this embodiment, the case where the honeycomb catalyst C is used as the lattice-shaped catalyst will be described. The honeycomb catalyst C is a catalyst having a honeycomb structure in which a plurality of through-holes C1 are formed. The through-holes C1, also referred to as cells, are, for example, small-diameter and long holes of 6 mm × 6 mm × 1000 mm.
[0028] The honeycomb catalyst according to this embodiment is a denitration catalyst used for purifying exhaust gas in a coal-fired power plant or the like. Examples of the material of the denitration catalyst include TiO 2Examples of such carriers include those supporting a catalyst component such as vanadium oxide. As the denitration catalyst is used for purifying exhaust gas, a coating layer about several micrometers thick with Si as a component is formed on the surface. When such a coating layer is formed, the performance of the denitration catalyst deteriorates. Therefore, regeneration is performed to remove the silica layer formed on the surface of the denitration catalyst and restore the performance. The quality of the catalyst in this case indicates the denitration performance of the regenerated catalyst, and is represented by, for example, the denitration rate. The catalyst is not limited to the denitration catalyst such as the honeycomb catalyst C according to the present embodiment, and is effective for catalysts that can be polished. For example, the catalyst polished by the catalyst polishing apparatus may be a catalyst used for blast furnace gas generated in a blast furnace of an ironworks, or a catalyst for purifying automobile exhaust gas. The three-way catalyst includes, for example, those in which a catalyst component of a noble metal such as Pt, Rh, and Pd is supported on a carrier such as ceramic. The quality of the catalyst in this case indicates the purification performance of the regenerated catalyst, and is represented by, for example, the purification rate.
[0029] As shown in FIG. 1, the catalyst polishing apparatus 1 includes a storage unit 10, an inflow path 20, an outflow path 30, a cyclone 40, a recovery unit 50, a bag filter 60, and a suction fan 70.
[0030] The honeycomb catalyst C to be polished by the catalyst polishing apparatus 1 is sandwiched between an upstream fixing member 22 in the inflow path 20 and a downstream fixing member 32 in the outflow path 30. The honeycomb catalyst C is fixed such that the flow path direction of the through holes C1 of the honeycomb catalyst C is substantially perpendicular to the horizontal plane. The abrasive A flows from below to above through the through holes C1 of the honeycomb catalyst C.
[0031] The storage unit 10 is a box-shaped member with an open upper part, and the abrasive A is stored inside.
[0032] The inflow path 20 is a flow path on the upstream side of the honeycomb catalyst C, and is a flow path through which the abrasive A is sucked and flows in together with air by the suction fan 70. The inflow path 20 includes a suction path 21 and an upstream fixing member 22.
[0033] The suction path 21 has an opening at its upstream end and has a vertically extending flow path through which abrasive A and air can flow. The upper end (downstream end) of the suction path 21 is connected to the upstream fixing member 22. The abrasive A stored in the storage portion 10 is sucked together with air by the suction force of the suction fan 70 as a suction portion and flows into the flow path of the inflow path 20 through the opening.
[0034] The upstream fixing member 22 has a vertically extending flow path through which abrasive A and air can flow, and the downstream side is connected to the lower end (upstream end) of the honeycomb catalyst C to fix the honeycomb catalyst C. The upstream side of the upstream fixing member 22 is connected to the suction path 21. The flow path of the upstream fixing member 22 and the flow path of the suction path 21 are vertically continuous flow paths. The abrasive A that has flowed in together with air from the suction path 21 flows into the through-hole C1 of the honeycomb catalyst C through the upstream fixing member 22.
[0035] In the flow path of the upstream fixing member 22, a regulating member for dispersing the abrasive A and a buffer member for reducing the flow rate of the abrasive A to prevent damage to the honeycomb catalyst C may be provided. On the other hand, in the catalyst polishing apparatus 1 according to the present embodiment, only the suction fan 70 as a suction portion is used as the power for sucking the abrasive A. The suction fan 70 sucks the abrasive A together with air in the vertical direction from the storage portion 10 through the suction path 21. Therefore, the abrasive A is sufficiently dispersed and flows into the upstream fixing member 22 in a state where the flow rate is low. For this reason, the catalyst polishing apparatus 1 can also be configured without providing the regulating member and the buffer member in the flow path of the upstream fixing member 22.
[0036] The outflow path 30 is a flow path on the downstream side of the honeycomb catalyst C. The outflow path 30 is a flow path through which the abrasive A and the polishing powder as the polished material generated by polishing the surface of the honeycomb catalyst C flow. The abrasive A and the polished material are sucked together with air by the suction fan 70 as a suction portion. A cyclone 40 is provided in the middle of the outflow path 30 to separate the abrasive A and the polished material.
[0037] The outflow path 30 includes a downstream fixing member 32 that is connected to the upper end (downstream end) of the honeycomb catalyst C to fix the honeycomb catalyst C, a downstream flow path 31 that connects the downstream fixing member 32 and the cyclone 40, and an abrasive supply path 33 that supplies the abrasive A separated by the cyclone 40 to the storage section 10.
[0038] The abrasive supply path 33 is one or a plurality of flow paths whose upstream end is connected to the cyclone 40. The abrasive supply path 33 is inclined or hangs downward from the cyclone 40 toward the storage section 10, and the downstream end of the abrasive supply path 33 opens above the storage section 10.
[0039] With the above configuration, the abrasive A that has flowed into the abrasive supply path 33 from the cyclone 40 falls by its own weight and is supplied to the storage section 10 from the opening at the downstream end.
[0040] The cyclone 40 is a known cyclone classifier and is arranged at a position higher than the storage section 10. The upstream end of the cyclone 40 is connected to the downstream flow path 31. The abrasive supply path 33 is connected to the lower part of the cyclone 40, and the abrasive A separated by the cyclone 40 flows through it. The downstream end of the cyclone 40 is connected to the transport pipe 41, and the downstream end of the transport pipe 41 is connected to the recovery section 50. The workpiece to be polished separated by the cyclone flows into the recovery section 50 through the transport pipe 41 together with air. The abrasive powder as the workpiece to be polished may contain a small amount of abrasive.
[0041] The recovery section 50 collects the workpiece to be polished of the honeycomb catalyst C. The recovery section 50 is constituted by, for example, a filter. The collected workpiece to be polished is stored in a storage section (not shown) provided at the lower part of the recovery section 50 and is recovered at a predetermined timing. The downstream end of the recovery section is connected to the connection pipe 51. The downstream end of the connection pipe 51 is connected to the bag filter 60. After the workpiece to be polished is recovered by the recovery section 50, the dust and the like flow into the bag filter 60 through the transport pipe 41 together with air.
[0042] The bag filter 60 is a known dust collection device. The bag filter 60 collects the dust in the air after the abrasive of the honeycomb catalyst C has been recovered. The collected dust is stored in a storage part (not shown) provided at the lower part of the bag filter 60 and is recovered at a predetermined timing. The downstream end of the bag filter 60 is connected to a connection pipe 61. The downstream end of the connection pipe 61 is connected to a suction fan 70 as a suction part. The clean air from which the dust has been removed by passing through the bag filter 60 is sucked by the suction fan 70 and discharged into the atmosphere through an exhaust duct 71.
[0043] <Quality determination method> Next, a quality determination method according to an embodiment of the present invention will be described with reference to FIG. 3. The quality determination method according to this embodiment is a method executed in the above-described catalyst polishing apparatus 1, and is a quality determination method in a polishing method in which the abrasive A is circulated through the through-holes C1 of the honeycomb catalyst C to polish the inner surface C1a of the through-holes C1. The quality determination method includes a polishing step (step S10), a recovery step (step S12), an analysis step (step S13), and a quality determination step (step S14). The quality determination method may include a classification step (step S11) between the polishing step (step S10) and the recovery step (step S12).
[0044] The quality determination method is not limited to determining the quality of the catalyst after regeneration. For example, the quality determination method may determine the quality of an unused catalyst to confirm the performance of the unused catalyst, or may determine the catalyst quality of a catalyst during use to consider the replacement timing of the catalyst during use. Further, the polishing in the polishing step is not limited to polishing for the purpose of catalyst regeneration. For example, the polishing in the polishing step may be performed not only on the regenerated catalyst but also on an unused catalyst or a catalyst during use. Also, the polishing in the polishing step may be performed to obtain a quality determination sample for confirming the performance of the catalyst or considering the replacement timing.
[0045] The polishing process (step S10) is a process of flowing the abrasive A through the through-hole C1 using the above-described catalyst polishing apparatus 1 to polish the inner surface C1a. The classification process (step S11) is a process of classifying the abrasive that has undergone the polishing process (step S10) in the cyclone 40.
[0046] The recovery process (step S12) is a process of recovering the polishing powder as the object to be polished generated by the polishing process (step S10). In the catalyst polishing apparatus 1 according to the present embodiment, as shown in FIG. 1, a recovery unit 50 is arranged on the downstream side of the cyclone 40 so that the polishing powder can be recovered after the abrasive A after the polishing process (step S10) is classified in the classification process (step S11). The recovery unit 50 collects the object to be polished of the honeycomb catalyst C flowing together with the air. The object to be polished collected in the recovery unit 50 is stored in a storage unit (not shown) provided at the lower part of the recovery unit 50, and is recovered at a predetermined timing, and the recovery process (step S12) is completed.
[0047] The analysis process (step S13) is a process of analyzing the polishing powder recovered in the recovery process (step S12). Specifically, in the analysis process (step S13), the component concentration of the polishing powder recovered in the recovery process (step S12) is measured and analyzed by a fluorescent X-ray analyzer. In addition, when pretreatment of the polishing powder as a sample is required for the analysis in the analysis process (step S13), the pretreatment of the sample may be performed. In the analysis process (step S13), the component concentration of the substance used for determination in the quality determination process (step S14) is derived. That is, in the analysis process (step S13), at least the component concentration of any one of the catalyst component, the binder / ash component, and the poisoning component is measured from at least the sample collected from the honeycomb catalyst C by the analysis. The substance used for determination in the quality determination process (step S14) is set according to the type of the abrasive A.
[0048] For example, when the abrasive A is white alumina, TiO in the quality determination process (step S14) 2 and SO 3is used to determine the component concentration. In this case, in the analysis step (step S13), at least the component concentration of at least one of Ti and S in the honeycomb catalyst C is measured by analysis, and TiO as a catalyst component 2 and SO as a binder - ash component 3 component concentration is derived. For example, in the analysis step (step S13), the component concentrations of Ti and S are measured by analysis. The component concentrations of Ti and S measured in the analysis step are converted into the component concentrations of TiO 2 and SO 3 respectively.
[0049] When the abrasive A is steel grit, in the quality determination step (step S14), TiO 2 , Al 2 O 3 and SO 3 component concentrations are used for determination. In this case, in the analysis step (step S13), at least the component concentration of at least one of Ti, Al, and S in the honeycomb catalyst C is measured by analysis, and TiO as a catalyst component 2 , Al as a binder - ash component 2 O 3 and SO 3 component concentrations are derived. For example, in the analysis step (step S13), the component concentrations of Ti, Al, and S are measured by analysis. The component concentrations of Ti, Al, and S measured in the analysis step are converted into the component concentrations of TiO 2 , Al 2 O 3 and SO 3 respectively.
[0050] When the abrasive A is green silicon carbide, in the quality determination step (step S14), TiO 2 , Al 2 O 3 and SO 3 component concentrations are used for determination. In this case, in the analysis step (step S13), at least the component concentration of at least one of Ti, Al, and S in the honeycomb catalyst C is measured by analysis, and TiO as a catalyst component 2 , Al as a binder - ash component2 O 3 and SO 3 to derive the component concentrations of. For example, in the analysis step (step S13), the component concentrations of Ti, Al, and S are measured by analysis. The component concentrations of Ti, Al, and S measured in the analysis step are respectively converted to the component concentrations of TiO 2 、Al 2 O 3 and SO 3 . Details will be described in the confirmation results of the relationship between the component concentration of the polishing powder and the denitration rate of the catalyst. When the honeycomb catalyst C is a three-way catalyst for automobiles, for example, in the analysis step (step S13), at least one of the component concentrations of Pt, Rh, and Pd as catalyst components is measured by analysis.
[0051] The quality determination step (step S14) is a step of determining the quality of the honeycomb catalyst C based on the component concentrations derived in the analysis step (step S13). More specifically, in the quality determination step (step S14), the quality of the honeycomb catalyst C is determined based on the related information in which the component concentration of the polishing powder and the denitration rate are associated. In the quality determination step (step S14), the quality of the honeycomb catalyst may be determined based on the related information in which the component concentration of the polishing powder and the denitration rate are associated.
[0052] More specifically, in the quality determination step (step S14), when the abrasive is white alumina, the quality of the honeycomb catalyst is determined based on the related information in which at least one of the component concentrations of TiO 2 and SO 3 derived by the analysis in the analysis step (step S13) and the denitration rate are associated. In the quality determination step (step S14), when the abrasive is steel grit or green silicon carbide, TiO 2 、Al 2 O 3 and SO 3The quality of the honeycomb catalyst may be determined based on the related information in which at least any of the component concentrations and the denitration rate are associated. When the honeycomb catalyst C is a three-way catalyst for an automobile, in the quality determination step (step S14), for example, based on the related information in which the component concentrations of catalyst components such as Pt, Rh, Pd, etc. and the components of the coating layer described above and the purification rate are associated, the quality of the honeycomb catalyst may be determined.
[0053] First, the relationship between the component concentration of the polishing powder and the denitration rate of the catalyst will be described using Tables 1 to 3 and Figures 4 to 11. Polishing was performed on a plurality of used catalysts using three types of abrasives, and five types of used catalysts with different denitration rates were prepared for each type of abrasive. Analysis was performed on the surface of each of the five types of used catalysts with different denitration rates prepared using the analyzer described later. Since it is presumed that the polishing powder of the same components is generated when the catalyst surface components are polished, the surface components of the catalyst were analyzed.
[0054] The denitration rates of the five types of used catalysts were measured by a method known in advance. As five types of used catalysts with different qualities of the catalyst, catalyst a which is a catalyst before regeneration and has a denitration rate of 37.0% at a molar ratio of 1.0, catalyst b which is a catalyst after regeneration and has a denitration rate of 76.6% at a molar ratio of 1.0, catalyst c with the same denitration rate of 68.2%, catalyst d with the same denitration rate of 68.9%, and catalyst e with the same denitration rate of 74.4% were confirmed.
[0055] The analysis by the analyzer was performed on three measurement points, namely, the inlet portion M1, the intermediate portion M2, and the outlet portion M3 of the through-hole C1.
[0056] In the analysis by the analyzer, the component concentrations of the related components were obtained, and the relationship between the component concentrations of the related components and the denitration rate was confirmed. The related components are the catalyst component, the binder-ash component, and the poisoning component. The catalyst component is a component constituting the catalyst. The binder-ash component is a component derived from the catalyst and coal ash. The poisoning component is a component of the exhaust gas that reduces the catalyst activity. Specifically, the catalyst component is TiO 2 , WO 3 and V2 O 5 is. The binder - ash component is SiO 2 and Al 2 O 3 CaO and SO 3 is. The poisoned component is Na 2 O, K 2 O and As 2 O 3 is. In the analysis, the component concentration of the elemental form is measured and converted into the related components to obtain the component concentration of the related components. For example, if the related components are TiO 2 or Al 2 O 3 SO 3 is, the component concentrations of Ti, Al, and S are measured respectively. The obtained component concentration of the elemental form is converted into the component concentration of the oxide.
[0057] As the analyzer, the measurement was carried out by the "Scanning Fluorescent X - ray Analyzer ZSX Primus IV" manufactured by Rigaku Corporation. The measurement methods were qualitative analysis and simple quantification (quantitative calculation by the FP method (Fundamental Parameter method)).
[0058] In the recovery part 50 of the catalyst grinding device 1, the grinding powder may also contain a part of the abrasive A used for grinding. In that case, it is considered to affect the analysis result. Therefore, in order to confirm the influence of the abrasive contained in the recovered grinding powder, the analysis of the grinding powder during the grinding of the above - mentioned 5 types of used catalysts was carried out and confirmed for each of the 3 types of abrasives. The measurement results for each of the 3 types of abrasives are shown in Tables 1 - 3 below respectively. As described above, the component concentrations of the compounds in Tables 1 - 3 are the values obtained by converting the component concentrations of the elemental form into oxides.
[0059]
Table 1
[0060] Table 1 shows the proportions (mass %) of the catalyst components, binder - ash components, poisoning components, and other components for each of catalysts a to e when abrasive A is white alumina, for the inlet portion M1, intermediate portion M2, outlet portion M3 of through - hole C1, and their average value AVE. The right - most column of Table 1 shows the denitration rates for catalysts a to e. When the component concentration cannot be detected, etc., it is indicated by a hyphen.
[0061] When abrasive A is white alumina (Al 2 O 3 ), to eliminate the influence of abrasive A remaining in the abrasive powder, Al 2 O 3 is excluded from the analysis results.
[0062] A graph with the denitration rates of catalysts a to e on the vertical axis and the component concentration (mass %) of TiO 2 in the catalyst components of catalysts a to e on the horizontal axis is shown in Fig. 4. As the component concentration of TiO 2 in the graph of Fig. 4, the average value AVE of the component concentrations at measurement points M1 to M3 is used. As shown in Table 1 and Fig. 4, it can be seen that the component concentration of TiO 2 increases as the denitration rate increases.
[0063] A graph with the denitration rates of catalysts a to e on the vertical axis and the component concentration (mass %) of SO 3 in the binder - ash components of catalysts a to e on the horizontal axis is shown in Fig. 5. As the component concentration of SO 3 in the graph of Fig. 5, the average value AVE of the component concentrations at measurement points M1 to M3 is used. As shown in Table 1 and Fig. 5, when the component concentration of SO 3 is 4.0 or more, it can be seen that the component concentration of SO 3 decreases as the denitration rate increases.
[0064] Therefore, the denitration rate of the used catalyst, and TiO 2 and SO 3The component concentration can be said to be correlated. Therefore, the quality of the catalyst indicated by the denitration rate can be determined based on the concentration of at least one of the components of the polishing powder, TiO 2 and SO 3 . The quality of the honeycomb catalyst can be determined in the quality determination step (step S14) based on the related information derived in advance, which associates at least one of the component concentrations of TiO 2 and SO 3 with the denitration rate.
[0065] In this embodiment, the related information associating the component concentrations of TiO 2 and SO 3 with the denitration rate has been derived in advance. Also, the quality of the catalyst indicated by the denitration rate is determined based on the related information associating the component concentrations of TiO 2 and SO 3 with the denitration rate.
[0066] In the quality determination step (step S14), the quality of the honeycomb catalyst C is determined based on the component concentrations of the polishing powder analyzed in the analysis step (step S13). For example, when the abrasive A is white alumina, in the quality determination step (step S14), the quality of the honeycomb catalyst C can be determined based on the related information associating at least one of the component concentrations of TiO 2 and SO 3 with the denitration rate.
[0067] In this embodiment, when the abrasive A is white alumina, in the quality determination step (step S14), the quality of the honeycomb catalyst C is determined based on the related information associating the component concentrations of TiO 2 and SO 3 with the denitration rate.
[0068] More specifically, in the quality determination step (step S14), when the pass determination criterion for the quality of the catalyst is set such that the denitration rate is 74.0% or more, if at least one of the component concentration of TiO 2 is 82.0% or more and the component concentration of SO 3 is 2.0% or less, the quality of the honeycomb catalyst C can be determined to be qualified.
[0069] In this embodiment, in the quality determination step (step S14), when the pass determination criterion for the quality of the catalyst is set such that the denitration rate is 74.0% or more, if the component concentration of TiO 2 is 82.0% or more and the component concentration of SO 3 is 2.0% or less, the quality of the honeycomb catalyst C is determined to be qualified.
[0070]
Table 2
[0071] Table 2 shows the ratios (mass %) of the catalyst components, binder - ash components, poisoning components, and other components for each of catalysts a to e when the abrasive A is steel grit, for the inlet portion M1, intermediate portion M2, outlet portion M3 of the through - hole C1, and their average value AVE. The denitration rates for catalysts a to e are shown in the right - most column of Table 1. When the component concentration cannot be detected, etc., it is indicated by a hyphen.
[0072] A graph with the denitration rates of catalysts a to e on the vertical axis and the component concentration (mass %) of TiO 2 in the catalyst components of catalysts a to e on the horizontal axis is shown in FIG. 6. As the component concentration of TiO 2 in the graph of FIG. 6, the average value AVE of the component concentrations at the measurement points M1 to M3 is used. As shown in Table 2 and FIG. 6, it can be seen that the component concentration of TiO 2 increases as the denitration rate increases.
[0073] The denitration rate of catalysts a to e is plotted on the vertical axis, and the Al content concentration (mass %) of the binder-ash components of catalysts a to e is plotted on the horizontal axis in the graph shown in Fig. 7. As the Al content concentration in the graph of Fig. 7, the average value AVE of the component concentrations at measurement points M1 to M3 is used. As shown in Table 2 and Fig. 7, it can be seen that the Al content of the binder-ash component decreases as the denitration rate increases. 2 O 3 content concentration. The graph shown in Fig. 7 uses the average value AVE of the component concentrations at measurement points M1 to M3 as the Al content concentration. As shown in Table 2 and Fig. 7, it can be seen that the Al content of the binder-ash component decreases as the denitration rate increases. 2 O 3 content concentration. As shown in Table 2 and Fig. 7, it can be seen that the Al content of the binder-ash component decreases as the denitration rate increases. 2 O 3 content concentration. As shown in Table 2 and Fig. 7, it can be seen that the Al content of the binder-ash component decreases as the denitration rate increases.
[0074] The denitration rate of catalysts a to e is plotted on the vertical axis, and the SO content concentration (mass %) of the binder-ash components of catalysts a to e is plotted on the horizontal axis in the graph shown in Fig. 8. As the SO content concentration in the graph of Fig. 8, the average value AVE of the component concentrations at measurement points M1 to M3 is used. As shown in Table 2 and Fig. 8, when the SO content concentration is 4.0 or more, it can be seen that the SO content concentration decreases as the denitration rate increases. 3 content concentration. The graph shown in Fig. 8 uses the average value AVE of the component concentrations at measurement points M1 to M3 as the SO content concentration. As shown in Table 2 and Fig. 8, when the SO content concentration is 4.0 or more, it can be seen that the SO content concentration decreases as the denitration rate increases. 3 content concentration. As shown in Table 2 and Fig. 8, when the SO content concentration is 4.0 or more, it can be seen that the SO content concentration decreases as the denitration rate increases. 3 content concentration. As shown in Table 2 and Fig. 8, when the SO content concentration is 4.0 or more, it can be seen that the SO content concentration decreases as the denitration rate increases. 3 content concentration. As shown in Table 2 and Fig. 8, when the SO content concentration is 4.0 or more, it can be seen that the SO content concentration decreases as the denitration rate increases.
[0075] Therefore, it can be said that there is a correlation between the denitration rate of the used catalyst and the component concentrations of TiO, Al, 2 Al 2 O 3 and SO. 3 Therefore, the quality of the catalyst indicated by the denitration rate can be determined based on the component concentration of at least one of TiO, Al, 2 Al 2 O 3 and SO. 3 By deriving in advance the relevant information in which the component concentration of at least one of TiO, Al, 2 Al 2 O 3 and SO, 3 is associated with the denitration rate, it is possible to determine the quality of the honeycomb catalyst based on the derived relevant information in the quality determination step (step S14).
[0076] In this embodiment, TiO, Al, 2 Al2 O 3 and SO 3 has previously derived the associated information related to the component concentrations of and the denitration rate. Further, the quality of the catalyst indicated by the denitration rate is TiO of the polishing powder 2 Al 2 O 3 and SO 3 is determined based on the associated information related to the component concentrations of and the denitration rate.
[0077] When the abrasive A is steel grit, in the quality determination step (step S14), based on the associated information related to at least any one of the component concentrations of TiO 2 Al 2 O 3 and SO 3 derived by the analysis in the analysis step (step S13) and the denitration rate, the quality of the honeycomb catalyst C can be determined.
[0078] In this embodiment, when the abrasive A is steel grit, in the quality determination step (step S14), based on the associated information related to at least any one of the component concentrations of TiO 2 Al 2 O 3 and SO 3 derived by the analysis in the analysis step (step S13) and the denitration rate, the quality of the honeycomb catalyst C is determined.
[0079] More specifically, in the quality determination step (step S14), when the pass determination criterion for the quality of the catalyst is that the denitration rate is 74.0% or more, the component concentration of TiO 2 derived by the analysis in the analysis step (step S13) is 81.9% or more, the component concentration of Al 2 O 3 is 1.0% or less, and the component concentration of SO 3 is 2.0% or less, in at least any one of the cases, the quality of the honeycomb catalyst C can be determined as qualified.
[0080] In this embodiment, when the pass / fail criterion for the quality of the catalyst is set such that the denitration rate is 74.0% or higher in the quality determination step (step S14), the TiO 2 component concentration is 81.9% or higher, the Al 2 O 3 component concentration is 1.0% or lower, and the SO 3 component concentration is 2.0% or lower as derived from the analysis in the analysis step (step S13), the quality of the honeycomb catalyst C is determined to be acceptable.
[0081]
Table 3
[0082] Table 3 shows the ratios (mass %) of the catalyst components, binder - ash components, poisoning components, and other components for each of catalysts a to e when abrasive A is green silicon carbide, for the inlet portion M1, intermediate portion M2, outlet portion M3 of the through - hole C1, and their average value AVE respectively. The denitration rates for catalysts a to e are shown in the right - most column of Table 1. When the component concentration cannot be detected, etc., it is indicated by a hyphen.
[0083] Since abrasive A is green silicon carbide (SiC), abrasive A may contain a small amount of SiO 2 derived from green silicon carbide. To eliminate the influence in this case, the SiO 2 in the binder - ash components is excluded from the analysis results.
[0084] A graph with the denitration rates of catalysts a to e on the vertical axis and the TiO 2 component concentration (mass %) of the catalyst components of catalysts a to e on the horizontal axis is shown in FIG. 9. As the TiO 2 component concentration in the graph of FIG. 9, the average value AVE of the component concentrations at measurement points M1 to M3 is used. As shown in Table 3 and FIG. 9, it can be seen that the TiO 2 component concentration increases as the denitration rate increases.
[0085] The denitration rates of catalysts a to e are plotted on the vertical axis, and the Al content concentration (mass %) of the binder-ash components of catalysts a to e is plotted on the horizontal axis in the graph shown in Fig. 10. As the Al content concentration in the graph of Fig. 10, the average value AVE of the component concentrations at measurement points M1 to M3 is used. As shown in Table 3 and Fig. 10, it can be seen that the Al content concentration of the binder-ash component decreases as the denitration rate increases. 2 O 3 The graph with the denitration rates of catalysts a to e on the vertical axis and the Al content concentration (mass %) of the binder-ash components of catalysts a to e on the horizontal axis is shown in Fig. 10. As the Al content concentration in the graph of Fig. 10, the average value AVE of the component concentrations at measurement points M1 to M3 is used. As shown in Table 3 and Fig. 10, it can be seen that the Al content concentration of the binder-ash component decreases as the denitration rate increases. 2 O 3 As the Al content concentration in the graph of Fig. 10, the average value AVE of the component concentrations at measurement points M1 to M3 is used. As shown in Table 3 and Fig. 10, it can be seen that the Al content concentration of the binder-ash component decreases as the denitration rate increases. 2 O 3 It can be seen that the Al content concentration of the binder-ash component decreases as the denitration rate increases.
[0086] The graph with the denitration rates of catalysts a to e on the vertical axis and the SO content concentration (mass %) of the binder-ash components of catalysts a to e on the horizontal axis is shown in Fig. 11. As the SO content concentration in the graph of Fig. 11, the average value AVE of the component concentrations at measurement points M1 to M3 is used. As shown in Table 3 and Fig. 11, when the SO content concentration is 4.0 or more, it can be seen that the SO content concentration decreases as the denitration rate increases. 3 The graph with the denitration rates of catalysts a to e on the vertical axis and the SO content concentration (mass %) of the binder-ash components of catalysts a to e on the horizontal axis is shown in Fig. 11. As the SO content concentration in the graph of Fig. 11, the average value AVE of the component concentrations at measurement points M1 to M3 is used. As shown in Table 3 and Fig. 11, when the SO content concentration is 4.0 or more, it can be seen that the SO content concentration decreases as the denitration rate increases. 3 As the SO content concentration in the graph of Fig. 11, the average value AVE of the component concentrations at measurement points M1 to M3 is used. As shown in Table 3 and Fig. 11, when the SO content concentration is 4.0 or more, it can be seen that the SO content concentration decreases as the denitration rate increases. 3 When the SO content concentration is 4.0 or more, 3 it can be seen that the SO content concentration decreases as the denitration rate increases.
[0087] Therefore, it can be said that there is a correlation between the denitration rate of the used catalyst and the component concentrations of TiO, Al, O, and SO. Thus, the quality of the catalyst indicated by the denitration rate can be determined based on the component concentration of at least one of TiO, Al, O, and SO in the polishing powder. By deriving in advance the related information in which the component concentration of at least one of TiO, Al, O, and SO is associated with the denitration rate, in the quality determination step (step S14), it is possible to determine the quality of the honeycomb catalyst based on the derived related information. 2 Al 2 O 3 and SO 3 Therefore, it can be said that there is a correlation between the denitration rate of the used catalyst and the component concentrations of TiO, Al, O, and SO. Thus, the quality of the catalyst indicated by the denitration rate can be determined based on the component concentration of at least one of TiO, Al, O, and SO in the polishing powder. By deriving in advance the related information in which the component concentration of at least one of TiO, Al, O, and SO is associated with the denitration rate, in the quality determination step (step S14), it is possible to determine the quality of the honeycomb catalyst based on the derived related information. 2 Al 2 O 3 and SO 3 Therefore, it can be said that there is a correlation between the denitration rate of the used catalyst and the component concentrations of TiO, Al, O, and SO. Thus, the quality of the catalyst indicated by the denitration rate can be determined based on the component concentration of at least one of TiO, Al, O, and SO in the polishing powder. By deriving in advance the related information in which the component concentration of at least one of TiO, Al, O, and SO is associated with the denitration rate, in the quality determination step (step S14), it is possible to determine the quality of the honeycomb catalyst based on the derived related information. 2 Al 2 O 3 and SO 3 Therefore, it can be said that there is a correlation between the denitration rate of the used catalyst and the component concentrations of TiO, Al, O, and SO. Thus, the quality of the catalyst indicated by the denitration rate can be determined based on the component concentration of at least one of TiO, Al, O, and SO in the polishing powder. By deriving in advance the related information in which the component concentration of at least one of TiO, Al, O, and SO is associated with the denitration rate, in the quality determination step (step S14), it is possible to determine the quality of the honeycomb catalyst based on the derived related information.
[0088] In this embodiment, TiO 2, Al 2 O 3 and SO 3 The related information associating the component concentrations of and the denitration rate has been derived in advance. Also, the quality of the catalyst indicated by the denitration rate is determined based on the related information associating the component concentrations of TiO 2 , Al 2 O 3 and SO 3 with the denitration rate.
[0089] When the abrasive A is silicon carbide green, in the quality determination step (step S14), the quality of the honeycomb catalyst C can be determined based on the related information associating at least any one of the component concentrations of TiO 2 , Al 2 O 3 and SO 3 with the denitration rate.
[0090] In this embodiment, when the abrasive is silicon carbide green, in the quality determination step (step S14), the quality of the honeycomb catalyst C is determined based on the related information associating the component concentrations of TiO 2 , Al 2 O 3 and SO 3 with the denitration rate.
[0091] More specifically, in the quality determination step (step S14), when the pass criterion for the quality of the catalyst is that the denitration rate is 74.0% or more, the quality of the honeycomb catalyst C can be determined to be qualified when at least any one of the component concentrations of TiO 2 is 85.5% or more, the component concentration of Al 2 O 3 is 1.0% or less, and the component concentration of SO 3 is 2.0% or less.
[0092] In this embodiment, in the quality determination step (step S14), when the pass determination criterion for the quality of the catalyst is set such that the denitration rate is 74.0% or more, the TiO 2 component concentration derived from the analysis in the analysis step (step S13) is 85.5% or more, and the Al 2 O 3 component concentration is 1.0% or less, and the SO 3 component concentration is 2.0% or less, the quality of the honeycomb catalyst C is determined to be acceptable.
[0093] The catalyst targeted by this quality determination method is not limited to the denitration catalyst as described above, and can also be applied to catalysts used in blast furnaces of steelworks, three-way catalysts of automobiles, etc. In the quality determination step (step S14), when the honeycomb catalyst C is a three-way catalyst of an automobile, a process for determining the quality of the honeycomb catalyst C based on components such as Pt, Rh, Pd, etc. as components of the honeycomb catalyst C is executed. In the quality determination step (step S14), for example, the quality of the honeycomb catalyst may be determined based on the related information in which the component concentrations of the above-mentioned catalyst components such as Pt, Rh, Pd, etc. and the component of the coating layer are associated with the purification rate. In this case, when the catalyst components such as Pt, Rh, Pd, etc. are less than the determination reference value as the related information, it is determined as non-conforming, assuming that the purification performance has deteriorated due to the coating layer formed on the catalyst. Also, when the catalyst components such as Pt, Rh, Pd, etc. are equal to or more than the determination reference value as the related information, the catalyst is determined as conforming, assuming that the formed coating layer is thin and has the required purification performance.
[0094] According to the quality determination method according to the present embodiment described above, the following effects can be obtained. Since the denitration catalyst of a coal-fired power plant deteriorates in performance when used continuously, it has been necessary to replace it with a new catalyst or to restore the performance such as regenerating the used catalyst. As a catalyst regeneration technology, mainly methods of washing with water or chemicals, methods of impregnating the used catalyst with the catalyst active component again, and polishing as a method of physically scraping off the coating on the catalyst surface are known.
[0095] As for the quality control of the regeneration operation, in the case of the method of cleaning or the method of impregnating the used catalyst with the catalytic active component, it is managed by performing reliable process control, visual inspection, extracting several catalysts as samples for inspection such as denitration rate, observation and component analysis of the catalyst surface, and component analysis of the catalyst itself. In the case of the method by polishing, in addition to the above quality control, the wall thickness is measured at the timing before and after regeneration by polishing for all the catalysts to grasp and manage the polishing state.
[0096] To ensure a certain level of quality, as a quality control method for the regenerated catalyst, simple inspections such as visual inspection and wall thickness measurement, and detailed inspections such as confirmation of the denitration rate, surface observation, and component analysis are carried out. However, since the detailed inspection is a destructive inspection, it cannot be carried out for all the regenerated catalysts. Therefore, the simple inspection is carried out for all, and the detailed inspection is carried out by sampling. It may be difficult to perform a simple inspection and it may not be possible to detect at the inner back side such as the central part of the through hole C1.
[0097] Also, more precise quality control of the catalyst is assumed to be applicable not only to the quality control of the regenerated catalyst as described above, but also to catalysts that can be polished, such as unused catalysts and catalysts during use.
[0098] From the above, in order to improve the quality control accuracy of the catalyst, it was necessary to establish a simple inspection method that can be implemented for all with the same accuracy as the detailed inspection. The quality determination method according to the present invention can determine the quality of the catalyst with high precision without destroying the honeycomb catalyst.
[0099] <Other Modifications> In the above embodiment, the quality of the catalyst was determined by the catalytic component, binder - ash component, etc. of the polishing powder, but it is not limited to this, and it may be determined by the poisoning component of the polishing powder. In the above embodiment, the components were measured separately after collecting the polishing powder after cyclone classification, but it is not limited to this, and the components may be measured continuously as they are after collection.
[0100] In the above-described embodiment, in the quality determination step (step S14), the quality of the honeycomb catalyst C is determined based on the related information in which the component concentration of the polishing powder and the denitration rate are associated. The quality determination step (step S14) may determine the quality of the honeycomb catalyst C based on the related information in which the component concentration of the polishing powder and the surface observation result are associated. Specifically, the surface observation result is the observation result of the reflected electron composite image (COMPO image) of a scanning electron microscope (SEM). Analyze and derive in advance the component concentration of the catalyst when it can be determined that the quality of the catalyst is qualified based on the surface observation result. The pass result of the quality of the catalyst as the surface observation result and the derived component concentration can be associated to obtain a determination reference value as the related information.
[0101] As described above, some embodiments of the present invention have been described. However, these embodiments are merely examples and do not limit the technical scope of the present invention. The present invention can take various other embodiments, and furthermore, various changes such as omission and substitution can be made without departing from the gist of the present invention. These embodiments and their modifications are included in the scope and gist of the invention described in this specification and the like, and are also included in the invention described in the claims and its equivalent scope.
Explanation of Reference Numerals
[0102] A Abrasive C Honeycomb catalyst (catalyst) C1 Through-hole C1a Inner surface S10 Polishing step S12 Recovery step S13 Analysis step S14 Quality determination step
Claims
1. A quality determination method in a method for polishing a catalyst by flowing an abrasive through a through-hole of the catalyst to polish the inner surface of the through-hole, comprising: a polishing step of flowing the abrasive through the through-hole to polish the inner surface; a recovery step of recovering abrasive powder generated by the polishing step; an analysis step of analyzing the abrasive powder recovered in the recovery step; a quality determination step of determining the quality of the catalyst based on the component concentration derived in the analysis step.
2. The catalyst is a denitration catalyst, and in the quality determination step, the quality of the catalyst is determined based on the related information in which the component concentration of the abrasive powder is associated with the denitration rate. The quality determination method according to claim 1.
3. The abrasive is white alumina, and in the analysis step, the component concentration of at least one of Ti and S in the catalyst is measured by analysis, and in the quality determination step, the quality of the catalyst is determined based on the component concentration of at least one of Ti and S measured in the analysis step. The quality determination method according to claim 1 or 2.
4. In the quality determination step, when the pass determination criterion for the quality of the catalyst is that the denitration rate is 74.0% or more, the TiO of Ti measured in the analysis step ２ The component concentration in terms of conversion is 82.0% or more, and the SO of S ３ The quality determination method according to claim 3, wherein when at least one of the component concentrations in terms of conversion is 2.0% or less, the quality of the catalyst is determined to be qualified.
5. The abrasive is steel grit, and in the analysis step, the component concentration of at least one of Ti, Al, and S in the catalyst is measured by analysis, and in the quality determination step, the quality of the catalyst is determined based on the component concentration of at least one of Ti, Al, and S measured in the analysis step. The quality determination method according to claim 1 or 2.
6. In the quality determination step, when the pass determination criterion for the quality of the catalyst is that the denitration rate is 74.0% or more, the TiO of Ti measured in the analysis step ２ The component concentration in terms of conversion is 81.9% or more, and the Al of Al ２ O ３ When the component concentration in terms of conversion is 1.0% or less and the component concentration in terms of conversion of S to SO ３ is 2.0% or less, the quality of the catalyst is determined to be qualified. The quality determination method according to claim 5.
7. The abrasive is green silicon carbide, and in the analysis step, the component concentration of at least one of Ti, Al, and S in the catalyst is measured by analysis, and in the quality determination step, the quality of the catalyst is determined based on the component concentration of at least one of Ti, Al, and S measured in the analysis step. The quality determination method according to claim 1 or 2.
8. In the quality determination step, when the pass criterion for the quality of the catalyst is that the denitration rate is 74.0% or more, the component concentration of Ti in terms of TiO ２ measured in the analysis step is 85.5% or more, and the component concentration of Al in terms of Al ２ O ３ is 1.0% or less, and the component concentration of S in terms of SO ３ is 2.0% or less, in at least any one of the cases, the quality of the catalyst is determined to be qualified. The quality determination method according to claim 7.
9. In the recovery step, the abrasive powder is recovered after classifying the abrasive that has undergone the polishing step. The quality determination method according to claim 1 or 2.
10. In the analysis step, the component concentration of the abrasive powder recovered in the recovery step is analyzed by an X-ray analyzer. The quality determination method according to claim 1 or 2.