CA2571044C - Method of testing denitration catalyst - Google Patents
Method of testing denitration catalyst Download PDFInfo
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- CA2571044C CA2571044C CA2571044A CA2571044A CA2571044C CA 2571044 C CA2571044 C CA 2571044C CA 2571044 A CA2571044 A CA 2571044A CA 2571044 A CA2571044 A CA 2571044A CA 2571044 C CA2571044 C CA 2571044C
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- 239000003054 catalyst Substances 0.000 title claims abstract description 152
- 238000010998 test method Methods 0.000 title claims abstract description 16
- 239000007789 gas Substances 0.000 claims abstract description 85
- 238000012360 testing method Methods 0.000 claims abstract description 85
- 230000003197 catalytic effect Effects 0.000 claims abstract description 25
- 238000000034 method Methods 0.000 claims abstract description 23
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims abstract description 10
- 239000003546 flue gas Substances 0.000 claims abstract description 10
- 238000011156 evaluation Methods 0.000 claims description 9
- 230000007704 transition Effects 0.000 claims description 3
- 230000002459 sustained effect Effects 0.000 description 10
- 230000006866 deterioration Effects 0.000 description 5
- 239000012530 fluid Substances 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000004088 simulation Methods 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 230000002542 deteriorative effect Effects 0.000 description 2
- 238000013213 extrapolation Methods 0.000 description 2
- 238000011056 performance test Methods 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 239000003034 coal gas Substances 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000002737 fuel gas Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 239000003209 petroleum derivative Substances 0.000 description 1
- 238000009790 rate-determining step (RDS) Methods 0.000 description 1
- 239000012495 reaction gas Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N31/00—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/86—Catalytic processes
- B01D53/8621—Removing nitrogen compounds
- B01D53/8625—Nitrogen oxides
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N31/00—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods
- G01N31/10—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods using catalysis
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/20—Reductants
- B01D2251/206—Ammonium compounds
- B01D2251/2062—Ammonia
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T436/00—Chemistry: analytical and immunological testing
- Y10T436/17—Nitrogen containing
- Y10T436/173845—Amine and quaternary ammonium
- Y10T436/175383—Ammonia
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T436/00—Chemistry: analytical and immunological testing
- Y10T436/17—Nitrogen containing
- Y10T436/177692—Oxides of nitrogen
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T436/00—Chemistry: analytical and immunological testing
- Y10T436/17—Nitrogen containing
- Y10T436/177692—Oxides of nitrogen
- Y10T436/178459—Only nitrogen dioxide
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T436/00—Chemistry: analytical and immunological testing
- Y10T436/17—Nitrogen containing
- Y10T436/177692—Oxides of nitrogen
- Y10T436/179228—Both nitrogen oxide and dioxide
Abstract
The present invention provides a method of testing an NO x removal catalyst, which method enables assessment of actual catalytic performance in consideration of gas flow condition in the gas conduits of the NO x removal catalyst.
The method of testing a honeycomb-form NO x removal catalyst for use in a flue gas NO x removal apparatus, the catalyst having gas conduits for feeding a discharge gas from an inlet to an outlet of each conduit and performing NO x removal on the sidewalls of the conduit, wherein the method includes providing a first test piece, which is a portion of the catalyst having a length covering the entirety of a turbulent flow zone in which a gas to be treated that has been fed into the gas conduits through the inlet of the NO x removal catalyst forms a turbulent flow and further covering at least a portion of a laminar flow zone in which the turbulent flow is rectified to form a laminar flow; performing a first NO x removal test of the provided first test piece; subsequently, performing a second NO x removal test of a second test piece, which is obtained through cutting out a catalyst portion of a length covering the turbulent flow zone; and assessing, on the basis of the test results, catalytic performance of the turbulent flow zone and that of the laminar flow zone, whereby catalytic performance of the NO x removal catalyst is assessed.
The method of testing a honeycomb-form NO x removal catalyst for use in a flue gas NO x removal apparatus, the catalyst having gas conduits for feeding a discharge gas from an inlet to an outlet of each conduit and performing NO x removal on the sidewalls of the conduit, wherein the method includes providing a first test piece, which is a portion of the catalyst having a length covering the entirety of a turbulent flow zone in which a gas to be treated that has been fed into the gas conduits through the inlet of the NO x removal catalyst forms a turbulent flow and further covering at least a portion of a laminar flow zone in which the turbulent flow is rectified to form a laminar flow; performing a first NO x removal test of the provided first test piece; subsequently, performing a second NO x removal test of a second test piece, which is obtained through cutting out a catalyst portion of a length covering the turbulent flow zone; and assessing, on the basis of the test results, catalytic performance of the turbulent flow zone and that of the laminar flow zone, whereby catalytic performance of the NO x removal catalyst is assessed.
Description
Description Method of Testing Denitration Catalyst Technical Field [0001]
The present invention relates to a method of testing an NO, removal catalyst, which method is performed for the purpose of assessing performance of NO, removal catalysts employed in a flue gas NO, removal apparatus installed in a facility such as a thermal power station.
Background Art [0002]
Conventionally, boilers provided in thermal power stations and a variety of large-scale boilers employing a fuel such as petroleum, coal, or fuel gas, waste incinerators, and similar apparatuses have been equipped with a flue gas NO,, removal apparatus which contains a plurality of NO,, removal catalyst layers.
The present invention relates to a method of testing an NO, removal catalyst, which method is performed for the purpose of assessing performance of NO, removal catalysts employed in a flue gas NO, removal apparatus installed in a facility such as a thermal power station.
Background Art [0002]
Conventionally, boilers provided in thermal power stations and a variety of large-scale boilers employing a fuel such as petroleum, coal, or fuel gas, waste incinerators, and similar apparatuses have been equipped with a flue gas NO,, removal apparatus which contains a plurality of NO,, removal catalyst layers.
[0003]
The above employed NO,, removal catalysts assume the form of honeycomb, plate, etc. During use, the catalytic performance of the catalysts is problematically deteriorated with elapse of time as a result of deposition, on the surface of the catalyst, of a substance which deteriorates the catalytic performance (hereinafter referred to as deteriorating substance) or through migration of the dissolved deteriorating substance into the catalyst.
The above employed NO,, removal catalysts assume the form of honeycomb, plate, etc. During use, the catalytic performance of the catalysts is problematically deteriorated with elapse of time as a result of deposition, on the surface of the catalyst, of a substance which deteriorates the catalytic performance (hereinafter referred to as deteriorating substance) or through migration of the dissolved deteriorating substance into the catalyst.
[0004]
Conventionally, the performance of the NOX removal catalysts has been managed by measuring NOX concentration and unreacted NH3 concentration on the inlet and outlet sides of respective catalysts. When a drop in total performance of a catalyst system is confirmed, old catalysts are replaced with new catalysts or regenerated catalysts in order of use age, and such replacement is carried out periodically.
Conventionally, the performance of the NOX removal catalysts has been managed by measuring NOX concentration and unreacted NH3 concentration on the inlet and outlet sides of respective catalysts. When a drop in total performance of a catalyst system is confirmed, old catalysts are replaced with new catalysts or regenerated catalysts in order of use age, and such replacement is carried out periodically.
[0005]
Generally, NO, removal catalysts are very expensive.
Thus, there has been proposed one approach for prolonging the service life of the NOX removal catalysts to as long a duration as possible by assessing the performance of each unit catalyst (see, for example, Patent Document 1).
Generally, NO, removal catalysts are very expensive.
Thus, there has been proposed one approach for prolonging the service life of the NOX removal catalysts to as long a duration as possible by assessing the performance of each unit catalyst (see, for example, Patent Document 1).
[0006]
In the aforementioned case, when the catalytic performance is evaluated by the percent contribution calculated on the basis of the NOX concentration, the catalyst(s) having actually deteriorated performance cannot be detected correctly. Thus, there has been proposed a performance assessment method which provides assessment results reflecting the actual state of the catalyst more acurately, the method including determining NH3 concentrations on the inlet and outlet sides of respective catalysts and taking into account the inlet mole ratio (i.e., inlet NH3/inlet NOX) (see, for example, Patent Document 2) [0007]
In an alternative performance evaluation method, instead of evaluating performance in an actual NO, removal apparatus, test pieces are cut out from an NO, removal catalyst, and the pieces are tested in a testing machine.
For example, SV values based on catalyst amount and reacted gas amount, AV values based on catalyst surface area and amount of reacted gas, and other parameters may be obtained.
In the aforementioned case, when the catalytic performance is evaluated by the percent contribution calculated on the basis of the NOX concentration, the catalyst(s) having actually deteriorated performance cannot be detected correctly. Thus, there has been proposed a performance assessment method which provides assessment results reflecting the actual state of the catalyst more acurately, the method including determining NH3 concentrations on the inlet and outlet sides of respective catalysts and taking into account the inlet mole ratio (i.e., inlet NH3/inlet NOX) (see, for example, Patent Document 2) [0007]
In an alternative performance evaluation method, instead of evaluating performance in an actual NO, removal apparatus, test pieces are cut out from an NO, removal catalyst, and the pieces are tested in a testing machine.
For example, SV values based on catalyst amount and reacted gas amount, AV values based on catalyst surface area and amount of reacted gas, and other parameters may be obtained.
[0008]
However, the aforementioned performance evaluation methods are developed without taking into account the flow of gas in the gas conduits, and overall catalytic performance of some NOX removal catalysts having a certain length cannot be fully evaluated.
However, the aforementioned performance evaluation methods are developed without taking into account the flow of gas in the gas conduits, and overall catalytic performance of some NOX removal catalysts having a certain length cannot be fully evaluated.
[0009]
Patent Document 1: Japanese Patent Publication (kokoku) No.
7-47108 (p. 2 to 3 and FIG. 1) Patent Document 2: Japanese Patent Application Laid-Open (kokai) No. 2004-066228 (Claims and other sections) Disclosure of the Invention Problems to be Solved by the Invention [0010]
Under such circumstances, an object of the present invention is to provide a method of testing an NOX removal catalyst, which method enables assessment of actual catalytic performance in consideration of gas flow conditions in the gas conduits of the NOX removal catalyst.
Means for Solving the Problems [00111 Accordingly, a first mode of the present invention for attaining the aforementioned object provides a method of testing a honeycomb-form NO,, removal catalyst for use in a flue gas NO., removal apparatus, the catalyst having gas conduits for feeding a discharge gas from an inlet to an outlet of each conduit and performing NO, removal on the sidewalls of the conduit, characterized in that the method comprises providing a first test piece, which is a portion of the catalyst having a length covering the entirety of a turbulent flow zone in which a gas to be treated that has been fed into the gas conduits through the inlet of the NO,, removal catalyst forms a turbulent flow and further covering at least a portion of a laminar flow zone in which the turbulent flow is rectified to form a laminar flow;
performing a first NO, removal test of the provided first test piece;
subsequently, performing a second NO, removal test of a second test piece, which is obtained through cutting out a catalyst portion of a length covering the turbulent flow zone; and assessing, on the basis of the test results, catalytic performance of the turbulent flow zone and that of the laminar flow zone, whereby catalytic performance of the NO,t removal catalyst is assessed.
[00121 According to the first mode, catalytic performance is evaluated in consideration of zone-dependent variation in gas flow condition in the gas conduits of the No, removal catalyst, to thereby enable the user to recognize in an actual state of use more accurately.
[0013]
A second mode of the present invention is drawn to a specific embodiment of the method of the first mode, wherein the turbulent flow zone has a length Lb (mm) represented by equation (A):
[0014]
(Fl) Lb = a (Ly/Lys) 220035(Ly=vin) (A) [0015]
(wherein Uin (m/s) represents a gas inflow rate, the aperture size Ly (mm) is an arbitrary parameter, Lys is an aperture size of 6 mm (constant value), and "a" is a constant failing within a range of 3 to 6, when the aperture size (Ly) is 6 mm and the gas inflow rate is 6 m/s).
(0016]
According to the second mode, the catalyst performance can be assessed more accurately by virtue of accurate determination of the length of the turbulent flow zone.
[0017]
A third mode of the present invention is drawn to a specific embodiment of the method of the first or second mode, wherein the first or second NO, removal test is performed while a model gas having a composition simulating the gas treated in an actual NO, removal apparatus is fed at a gas inflow rate equivalent to that employed in an actual NO.
removal apparatus, thereby determining catalyst performance.
[0018]
According to the third mode, the catalyst performance can be assessed accurately by virtue of test conditions reflecting those employed in an actual NOX removal apparatus.
[0019]
A fourth mode of the present invention is drawn to a specific embodiment of the method of the first or second mode, wherein the first or second NO, removal test is performed while a model gas having a composition simulating the gas treated in an actual NO,, removal apparatus is fed at a flow rate differing from that employed in an actual NO, removal apparatus, thereby determining catalyst performance in consideration of the relationship between gas inflow rate and reacted NO,.
[0020]
According to the fourth mode, the relationship between gas inflow rate and reacted NO, is taken into account.
Therefore, the catalyst performance can be assessed accurately, even though the model gas is fed at a flow rate differing from that employed in an actual NO, removal apparatus.
[0021]
A fifth mode of the present invention is drawn to a specific embodiment of the method of any of the first to fourth modes, wherein the first or second NO, removal test comprises determining NO, concentrations on the inlet and outlet sides of respective test pieces; determining NH3 concentrations on the inlet and outlet sides of respective test pieces; and determining percent NO,, removal (Ii) on the basis of an inlet mole ratio (i.e., inlet NH3/inlet NO,).
[0022]
According to the fifth mode, NOX concentrations and NH3 concentrations are determined on the inlet and outlet sides of respective NO, removal catalysts, and the percent NO, removal (i) is determined on the basis of an inlet mole ratio.
Therefore, the percent NO, removal, which is enhanced with increased mole ratio, can be evaluated accurately on an absolute basis.
[0023]
A sixth mode of the present invention is drawn to a specific embodiment of the method of the fifth mode, wherein the percent NOX removal (1) is determined on the basis of NH3 concentrations.
[0024]
According to the sixth mode, the percent NO, removal (Ti) of respective NOX removal catalysts is determined on the basis of NH3 concentrations rather than on the basis of NOX
concentrations. Therefore, the catalytic performance can be more reliably assessed.
[0025]
A seventh mode of the present invention is drawn to a specific embodiment of the method of the sixth mode, wherein the percent NO, removal (ii) is determined on the basis of the following equation (1).
[0026]
[F2]
~1 = {(inlet NH3 - outlet NH3)/(inlet NH3 - outlet NH3 + outlet NO.)}x100x(evaluation mole ratio/inlet mole ratio) (1) [0027]
According to the seventh mode, the percent NO, removal of each NOX removal catalyst can be accurately detected without variation.
Effects of the Invention [0028]
According to the present invention, catalytic performance is evaluated in consideration of the turbulent flow zone on the inlet side of a NO, removal catalyst and the laminar flow zone on the downstream side. Thus, actual performance of the catalyst can be assessed accurately.
According to one aspect of the invention there is provided a method of testing a honeycomb-form NO,, removal catalyst for use in a flue gas NO,, removal apparatus, the catalyst comprising gas conduits for feeding a discharge gas from an inlet to an outlet of each conduit and performing NO,, removal on the sidewalls of the conduit, the method comprising providing a first test piece comprising a portion of the catalyst having a first length, the first length comprising a turbulent flow zone sustaining turbulent flow and where a gas to be treated is fed into the gas conduits from the inlet and at least a portion of a laminar flow zone downstream of the turbulent flow zone where transition from turbulent flow and laminar flow occurs; performing a first NO,, removal test with the first test piece; subsequently, performing a second NO,, removal test with a second test piece, which is obtained by cutting out a second length of a catalyst portion covering the turbulent flow zone; and determining on the basis of test results, a catalytic performance of the turbulent flow zone and the laminar flow zone, whereby catalytic performance of the NO, removal catalyst is obtained.
Brief description of the Drawings [FIG. 11 A graph showing the results of Preliminary Test 1.
[FIG. 2]
A graph showing the results of Preliminary Test 2.
8a [FIG. 31 A graph showing the results of Preliminary Test 3.
[FIG. 4]
A graph showing the results of Preliminary Test 3.
[FIG. 5]
A graph showing the results of Performance Test of the present invention.
[FIG. 6]
A graph showing the results of Performance Test of the present invention.
[FIG. 7]
A graph showing the results of Example 1 of the present invention.
[FIG. 8]
A graph showing the results of Example 2 of the present invention.
[FIG. 91 A graph showing the results of Example 3 of the present invention.
Best Modes for Carrying Out the Invention [0030]
The present invention is applicable to any type of conventionally employed dust-through type NOX removal catalysts such as honeycomb catalysts. As used herein, the term "honeycomb catalyst" or "dust-through catalyst" refers to a catalyst unit including gas conduits having a cross-section of a polygon such as square, hexagon, or triangle, and performing catalytic reaction on the sidewalls of the gas conduits. No particular limitation is imposed on the form of the honeycomb catalyst, and typical forms include a cylinder containing gas conduits each having a hexagonal cross-section, and a rectangular prism containing gas conduits each having a square cross-section and arranged in a lattice-like form.
[00311 Conventionally, typical honeycomb NOX removal catalysts have a gas conduit pitch of 7 mm (aperture size: about 6 mm) and a length of about 700 mm to 1,000 mm. The present inventors have investigated the deterioration status of such catalysts after use along a longitudinal direction, and have found that the catalysts are more deteriorated on the inlet side than on the outlet side; the deterioration status is virtually unchanged in a portion ranging from the 300 mm site from the inlet to the outlet; and particularly, the catalysts are less involved in NOX removal reaction in a portion ranging from the outlet to the 300 mm site (from the outlet) than in a portion on the inlet side. The present invention has been accomplished on the basis of these findings. In other words, the present invention has been accomplished on the basis of the following finding by the inventors.
Specifically, an exhaust gas is fed into an NOX removal catalyst through gas conduits as a turbulent flow, and NOX
removal reaction is performed through contact of the gas with the sidewalls of the gas conduits. However, the flow of the thus-reacted exhaust gas is gradually straightened. Contact of the straightened gas flows (laminar flows) with the sidewalls of the conduits is minimized, thereby failing to attain effective NOR removal. Thus, catalytic performance cannot accurately assessed, if the reaction state in the turbulent flow zone and that of the laminar flow zone are not taken into account.
[0032]
Furthermore, one conceivable mechanism that explains reduction in NOR- or NH3-removal efficiency is as follows.
When an exhaust gas is fed from a wide space on the upstream side of the NOR removal catalyst to gas conduits of the catalyst, percent space of the gas is reduced from 1 to 0.6 to 0.7. The exhaust gas passes through the gas conduits while being in contact with the sidewalls of the conduits (catalyst surfaces) in a considerably turbulent state (in the turbulent flow zone). However, during the course of passage through the conduits, the gas flows are gradually regulated and straightened and mass transfer is controlled through diffusion only. After straightening, NOR molecules and NH3 molecules which are to collide with the sidewalls decrease in number considerably. Thus, catalytic performance must be evaluated in consideration of sustained turbulent flow distance (i.e., index for the depth of a portion where the gas flow remains in a turbulent state) of the catalyst.
[0033]
<Preliminary Test 1>
From a flue gas NOR removal catalyst which had been used for 50,000 hours in an actual flue gas NO, removal apparatus, catalyst portions (20 mm site to 850 mm site, from the inlet) were sampled in the longitudinal direction. TiO2 concentration and concentrations of catalyst deterioration substances (CaO and SO3) on the surface of each catalyst sample were determined.
[0034]
Catalyst portions (50 mm x 50 mm x 100 mm in length) were cut from a catalyst included in each catalyst layer, and set in a performance testing machine. Portions at the 100 mm site, the 450 mm site, and the 800 mm site were tested. The test gas was fed at a mole ratio (inlet mole ratio = inlet NH3/inlet NO,) of 0.82 and an AV (amount of treatable gas per unit surface area of the catalyst) of 6.5, and percent NO, removal 11 was calculated on the basis of the aforementioned formula employing NH3 concentration.
[0035]
The results are shown in FIG. 1. As a reference product, a new (unused) catalyst was also measured in terms of percent NO, removal r) .
[0036]
The results indicate that the catalyst was severely deteriorated in a portion ranging from the inlet to the 300 mm site, and that a portion ranging from the 450 mm to the outlet exhibits percent NOX removal almost equal to that of a new catalyst product.
[0037]
Patent Document 1: Japanese Patent Publication (kokoku) No.
7-47108 (p. 2 to 3 and FIG. 1) Patent Document 2: Japanese Patent Application Laid-Open (kokai) No. 2004-066228 (Claims and other sections) Disclosure of the Invention Problems to be Solved by the Invention [0010]
Under such circumstances, an object of the present invention is to provide a method of testing an NOX removal catalyst, which method enables assessment of actual catalytic performance in consideration of gas flow conditions in the gas conduits of the NOX removal catalyst.
Means for Solving the Problems [00111 Accordingly, a first mode of the present invention for attaining the aforementioned object provides a method of testing a honeycomb-form NO,, removal catalyst for use in a flue gas NO., removal apparatus, the catalyst having gas conduits for feeding a discharge gas from an inlet to an outlet of each conduit and performing NO, removal on the sidewalls of the conduit, characterized in that the method comprises providing a first test piece, which is a portion of the catalyst having a length covering the entirety of a turbulent flow zone in which a gas to be treated that has been fed into the gas conduits through the inlet of the NO,, removal catalyst forms a turbulent flow and further covering at least a portion of a laminar flow zone in which the turbulent flow is rectified to form a laminar flow;
performing a first NO, removal test of the provided first test piece;
subsequently, performing a second NO, removal test of a second test piece, which is obtained through cutting out a catalyst portion of a length covering the turbulent flow zone; and assessing, on the basis of the test results, catalytic performance of the turbulent flow zone and that of the laminar flow zone, whereby catalytic performance of the NO,t removal catalyst is assessed.
[00121 According to the first mode, catalytic performance is evaluated in consideration of zone-dependent variation in gas flow condition in the gas conduits of the No, removal catalyst, to thereby enable the user to recognize in an actual state of use more accurately.
[0013]
A second mode of the present invention is drawn to a specific embodiment of the method of the first mode, wherein the turbulent flow zone has a length Lb (mm) represented by equation (A):
[0014]
(Fl) Lb = a (Ly/Lys) 220035(Ly=vin) (A) [0015]
(wherein Uin (m/s) represents a gas inflow rate, the aperture size Ly (mm) is an arbitrary parameter, Lys is an aperture size of 6 mm (constant value), and "a" is a constant failing within a range of 3 to 6, when the aperture size (Ly) is 6 mm and the gas inflow rate is 6 m/s).
(0016]
According to the second mode, the catalyst performance can be assessed more accurately by virtue of accurate determination of the length of the turbulent flow zone.
[0017]
A third mode of the present invention is drawn to a specific embodiment of the method of the first or second mode, wherein the first or second NO, removal test is performed while a model gas having a composition simulating the gas treated in an actual NO, removal apparatus is fed at a gas inflow rate equivalent to that employed in an actual NO.
removal apparatus, thereby determining catalyst performance.
[0018]
According to the third mode, the catalyst performance can be assessed accurately by virtue of test conditions reflecting those employed in an actual NOX removal apparatus.
[0019]
A fourth mode of the present invention is drawn to a specific embodiment of the method of the first or second mode, wherein the first or second NO, removal test is performed while a model gas having a composition simulating the gas treated in an actual NO,, removal apparatus is fed at a flow rate differing from that employed in an actual NO, removal apparatus, thereby determining catalyst performance in consideration of the relationship between gas inflow rate and reacted NO,.
[0020]
According to the fourth mode, the relationship between gas inflow rate and reacted NO, is taken into account.
Therefore, the catalyst performance can be assessed accurately, even though the model gas is fed at a flow rate differing from that employed in an actual NO, removal apparatus.
[0021]
A fifth mode of the present invention is drawn to a specific embodiment of the method of any of the first to fourth modes, wherein the first or second NO, removal test comprises determining NO, concentrations on the inlet and outlet sides of respective test pieces; determining NH3 concentrations on the inlet and outlet sides of respective test pieces; and determining percent NO,, removal (Ii) on the basis of an inlet mole ratio (i.e., inlet NH3/inlet NO,).
[0022]
According to the fifth mode, NOX concentrations and NH3 concentrations are determined on the inlet and outlet sides of respective NO, removal catalysts, and the percent NO, removal (i) is determined on the basis of an inlet mole ratio.
Therefore, the percent NO, removal, which is enhanced with increased mole ratio, can be evaluated accurately on an absolute basis.
[0023]
A sixth mode of the present invention is drawn to a specific embodiment of the method of the fifth mode, wherein the percent NOX removal (1) is determined on the basis of NH3 concentrations.
[0024]
According to the sixth mode, the percent NO, removal (Ti) of respective NOX removal catalysts is determined on the basis of NH3 concentrations rather than on the basis of NOX
concentrations. Therefore, the catalytic performance can be more reliably assessed.
[0025]
A seventh mode of the present invention is drawn to a specific embodiment of the method of the sixth mode, wherein the percent NO, removal (ii) is determined on the basis of the following equation (1).
[0026]
[F2]
~1 = {(inlet NH3 - outlet NH3)/(inlet NH3 - outlet NH3 + outlet NO.)}x100x(evaluation mole ratio/inlet mole ratio) (1) [0027]
According to the seventh mode, the percent NO, removal of each NOX removal catalyst can be accurately detected without variation.
Effects of the Invention [0028]
According to the present invention, catalytic performance is evaluated in consideration of the turbulent flow zone on the inlet side of a NO, removal catalyst and the laminar flow zone on the downstream side. Thus, actual performance of the catalyst can be assessed accurately.
According to one aspect of the invention there is provided a method of testing a honeycomb-form NO,, removal catalyst for use in a flue gas NO,, removal apparatus, the catalyst comprising gas conduits for feeding a discharge gas from an inlet to an outlet of each conduit and performing NO,, removal on the sidewalls of the conduit, the method comprising providing a first test piece comprising a portion of the catalyst having a first length, the first length comprising a turbulent flow zone sustaining turbulent flow and where a gas to be treated is fed into the gas conduits from the inlet and at least a portion of a laminar flow zone downstream of the turbulent flow zone where transition from turbulent flow and laminar flow occurs; performing a first NO,, removal test with the first test piece; subsequently, performing a second NO,, removal test with a second test piece, which is obtained by cutting out a second length of a catalyst portion covering the turbulent flow zone; and determining on the basis of test results, a catalytic performance of the turbulent flow zone and the laminar flow zone, whereby catalytic performance of the NO, removal catalyst is obtained.
Brief description of the Drawings [FIG. 11 A graph showing the results of Preliminary Test 1.
[FIG. 2]
A graph showing the results of Preliminary Test 2.
8a [FIG. 31 A graph showing the results of Preliminary Test 3.
[FIG. 4]
A graph showing the results of Preliminary Test 3.
[FIG. 5]
A graph showing the results of Performance Test of the present invention.
[FIG. 6]
A graph showing the results of Performance Test of the present invention.
[FIG. 7]
A graph showing the results of Example 1 of the present invention.
[FIG. 8]
A graph showing the results of Example 2 of the present invention.
[FIG. 91 A graph showing the results of Example 3 of the present invention.
Best Modes for Carrying Out the Invention [0030]
The present invention is applicable to any type of conventionally employed dust-through type NOX removal catalysts such as honeycomb catalysts. As used herein, the term "honeycomb catalyst" or "dust-through catalyst" refers to a catalyst unit including gas conduits having a cross-section of a polygon such as square, hexagon, or triangle, and performing catalytic reaction on the sidewalls of the gas conduits. No particular limitation is imposed on the form of the honeycomb catalyst, and typical forms include a cylinder containing gas conduits each having a hexagonal cross-section, and a rectangular prism containing gas conduits each having a square cross-section and arranged in a lattice-like form.
[00311 Conventionally, typical honeycomb NOX removal catalysts have a gas conduit pitch of 7 mm (aperture size: about 6 mm) and a length of about 700 mm to 1,000 mm. The present inventors have investigated the deterioration status of such catalysts after use along a longitudinal direction, and have found that the catalysts are more deteriorated on the inlet side than on the outlet side; the deterioration status is virtually unchanged in a portion ranging from the 300 mm site from the inlet to the outlet; and particularly, the catalysts are less involved in NOX removal reaction in a portion ranging from the outlet to the 300 mm site (from the outlet) than in a portion on the inlet side. The present invention has been accomplished on the basis of these findings. In other words, the present invention has been accomplished on the basis of the following finding by the inventors.
Specifically, an exhaust gas is fed into an NOX removal catalyst through gas conduits as a turbulent flow, and NOX
removal reaction is performed through contact of the gas with the sidewalls of the gas conduits. However, the flow of the thus-reacted exhaust gas is gradually straightened. Contact of the straightened gas flows (laminar flows) with the sidewalls of the conduits is minimized, thereby failing to attain effective NOR removal. Thus, catalytic performance cannot accurately assessed, if the reaction state in the turbulent flow zone and that of the laminar flow zone are not taken into account.
[0032]
Furthermore, one conceivable mechanism that explains reduction in NOR- or NH3-removal efficiency is as follows.
When an exhaust gas is fed from a wide space on the upstream side of the NOR removal catalyst to gas conduits of the catalyst, percent space of the gas is reduced from 1 to 0.6 to 0.7. The exhaust gas passes through the gas conduits while being in contact with the sidewalls of the conduits (catalyst surfaces) in a considerably turbulent state (in the turbulent flow zone). However, during the course of passage through the conduits, the gas flows are gradually regulated and straightened and mass transfer is controlled through diffusion only. After straightening, NOR molecules and NH3 molecules which are to collide with the sidewalls decrease in number considerably. Thus, catalytic performance must be evaluated in consideration of sustained turbulent flow distance (i.e., index for the depth of a portion where the gas flow remains in a turbulent state) of the catalyst.
[0033]
<Preliminary Test 1>
From a flue gas NOR removal catalyst which had been used for 50,000 hours in an actual flue gas NO, removal apparatus, catalyst portions (20 mm site to 850 mm site, from the inlet) were sampled in the longitudinal direction. TiO2 concentration and concentrations of catalyst deterioration substances (CaO and SO3) on the surface of each catalyst sample were determined.
[0034]
Catalyst portions (50 mm x 50 mm x 100 mm in length) were cut from a catalyst included in each catalyst layer, and set in a performance testing machine. Portions at the 100 mm site, the 450 mm site, and the 800 mm site were tested. The test gas was fed at a mole ratio (inlet mole ratio = inlet NH3/inlet NO,) of 0.82 and an AV (amount of treatable gas per unit surface area of the catalyst) of 6.5, and percent NO, removal 11 was calculated on the basis of the aforementioned formula employing NH3 concentration.
[0035]
The results are shown in FIG. 1. As a reference product, a new (unused) catalyst was also measured in terms of percent NO, removal r) .
[0036]
The results indicate that the catalyst was severely deteriorated in a portion ranging from the inlet to the 300 mm site, and that a portion ranging from the 450 mm to the outlet exhibits percent NOX removal almost equal to that of a new catalyst product.
[0037]
<Preliminary Test 2>
An NO., removal catalyst which had been used in an actual flue gas NO,, removal apparatus was cut at the 600 mm site from the inlet (along the longitudinal direction), and the cut catalyst piece was set in a performance testing machine.
Percent NO, removal fl was determined at a plurality of sites at intervals of 100 mm under the following conditions: mole ratios (i.e., inlet mole ratio = inlet NH3/inlet NO,) of 0.6, 0.8, 1.0, and 1.2; 360 C; and fluid inflow rate of 6 m/s.
The results are shown in Table 1 and FIG. 2.
[0038]
As is clear from Table 1 and FIG. 2, percent NO, removal tends to increase in proportion to the distance from the inlet (i.e., length of the catalyst) and that the increase in percent NO, removal tends to be suppressed when the catalyst length exceeds a certain value. The tendency is attributable to the flow of exhaust gas being gradually straightened.
[0039]
[Table 1]
100 mm 200 mm 300 mm 400 mm 500 mm 600 mm Mole ratio 17.7 30.4 39.5 46.1 50.8 54.2 0.6 Mole ratio 21.3 36.9 48.3 56.7 62.9 67.4 0.8 Mole ratio 23.2 40.5 53.5 63.2 70.5 75.9 1.0 Mole ratio 24.0 42.0 55.4 65.4 73.0 78.6 1.2 [0040]
<Preliminary test 3>
A honeycomb catalyst (600 mm x 6 mm x 6 mm, aperture size: 6 mm (pitch: 7 mm)) was subjected to simulation under the following conditions: 350 C and fluid inflow rate (Uin):
4, 6, and 10 m/s.
[0041]
Through simulation, Uin and the distance from the inlet to a site where turbulent flow energy is lost in the course of transition from turbulent flow to laminar flow (hereinafter referred to as sustained turbulent flow distance (Lts)) were found to have the relationship shown in FIG. 3.
Specifically, sustained turbulent flow distance (Lts) values at fluid inflow rates (Uin) of 4, 6, and 10 m/s were calculated as 50, 80, and 180 mm, respectively.
[0042]
Theoretically, conditions of fluid are generally determined from inflow rate (Uin) and Reynolds number Re;
i.e., a parameter employing aperture size Ly (Re = Uin=Ly/v, v = 5.67 x 10-5 m2/S; constant).
[0043]
In a honeycomb catalyst having an aperture size of 6 mm, sustained turbulent flow distance Lts (mm) is derived from a product of inflow rate Uins (m/s) and aperture size Lys (mm).
Thus, the relationship between sustained turbulent flow distance Lts and a product of inflow rate Uins (Uin) and aperture size Lys (Ly), as shown in FIG. 3, was obtained.
An NO., removal catalyst which had been used in an actual flue gas NO,, removal apparatus was cut at the 600 mm site from the inlet (along the longitudinal direction), and the cut catalyst piece was set in a performance testing machine.
Percent NO, removal fl was determined at a plurality of sites at intervals of 100 mm under the following conditions: mole ratios (i.e., inlet mole ratio = inlet NH3/inlet NO,) of 0.6, 0.8, 1.0, and 1.2; 360 C; and fluid inflow rate of 6 m/s.
The results are shown in Table 1 and FIG. 2.
[0038]
As is clear from Table 1 and FIG. 2, percent NO, removal tends to increase in proportion to the distance from the inlet (i.e., length of the catalyst) and that the increase in percent NO, removal tends to be suppressed when the catalyst length exceeds a certain value. The tendency is attributable to the flow of exhaust gas being gradually straightened.
[0039]
[Table 1]
100 mm 200 mm 300 mm 400 mm 500 mm 600 mm Mole ratio 17.7 30.4 39.5 46.1 50.8 54.2 0.6 Mole ratio 21.3 36.9 48.3 56.7 62.9 67.4 0.8 Mole ratio 23.2 40.5 53.5 63.2 70.5 75.9 1.0 Mole ratio 24.0 42.0 55.4 65.4 73.0 78.6 1.2 [0040]
<Preliminary test 3>
A honeycomb catalyst (600 mm x 6 mm x 6 mm, aperture size: 6 mm (pitch: 7 mm)) was subjected to simulation under the following conditions: 350 C and fluid inflow rate (Uin):
4, 6, and 10 m/s.
[0041]
Through simulation, Uin and the distance from the inlet to a site where turbulent flow energy is lost in the course of transition from turbulent flow to laminar flow (hereinafter referred to as sustained turbulent flow distance (Lts)) were found to have the relationship shown in FIG. 3.
Specifically, sustained turbulent flow distance (Lts) values at fluid inflow rates (Uin) of 4, 6, and 10 m/s were calculated as 50, 80, and 180 mm, respectively.
[0042]
Theoretically, conditions of fluid are generally determined from inflow rate (Uin) and Reynolds number Re;
i.e., a parameter employing aperture size Ly (Re = Uin=Ly/v, v = 5.67 x 10-5 m2/S; constant).
[0043]
In a honeycomb catalyst having an aperture size of 6 mm, sustained turbulent flow distance Lts (mm) is derived from a product of inflow rate Uins (m/s) and aperture size Lys (mm).
Thus, the relationship between sustained turbulent flow distance Lts and a product of inflow rate Uins (Uin) and aperture size Lys (Ly), as shown in FIG. 3, was obtained.
Through the least squares method, sustained turbulent flow distance Lts at an aperture size (Lys) of 6 mm is approximately represented by the following equation (1).
[0044]
[F3]
Lts = 22e0.035(Lys-Uins) (1) [0045]
When the aperture size Lys is 6 mm (constant value), the aperture size Ly (mm) is an arbitrary parameter, and Uin (m/s) represents a gas inflow rate, sustained turbulent flow distance Lt can be represented by the following formula (2), which is a general equation.
[0046]
[F4]
Lt = (Ly/Lys) =22e0035(Ly-Uin) (2) (0047) The simulation results were compared with the approximate length (optimum length) of the actual catalyst, the length being such that the flow of the exhaust gas fed into the gas conduits is straightened. Specifically, the relationship between sustained turbulent flow distance Lt and the optimum length of an actual catalyst (i.e., the length of a stained-portion of the catalyst (stain length), which is an index for detecting straightening) was investigated. As shown in FIG. 4, in an actual stage of the employed apparatus, turbulent flow is maintained over a portion of the catalyst having a distance longer than the sustained turbulent flow distance Lt, which is derived through simulation. One possible reason of this phenomenon is that inflow rate is varied and flow of the fluid is disturbed.
[0048]
Accordingly, in an actual catalyst unit, the distance from the inlet to a site where straightening starts (i.e., the length of the turbulent flow zone) must be determined from the above stain length and a certain safety length.
Specifically, equation (2) must be multiplied by a constant "a," and the length of the turbulent flow zone of the actual catalyst Lb is considered to be represented by the following equation (3). Note that "a" is a constant falling within a range of 3 to 6, when the aperture size of a honeycomb catalyst is 6 mm (pitch: 7 mm) and the gas inflow rate is 6 m/s.
[0049]
[F5]
Lb = a=Lt (3) [0050]
In the aforementioned Test Example 1, a honeycomb catalyst having an aperture size of 6 mm (pitch: 7 mm) was used at a gas inflow rate of 6 m/s. Thus, Lt is 80 mm. When the constant "a" is adjusted to about 3.8, Lt is about 300 mm, which corresponds to the length of a severely deteriorated portion of the catalyst, whereas when the constant "a" is adjusted to about 5.6, Lt is about 450 mm, which corresponds to the length of a portion of the catalyst including a portion exhibiting catalytic performance equivalent to that of a new catalyst product.
[0051]
In the same honeycomb catalyst, when "a" falls within a range of 3 to 6, the,turbulent flow zone length Lb falls within a range of about 240 to 480 mm. The range of Lb virtually coincides with a range of about 300 to 450 mm, which is considered to be a length of an actual NOX removal catalyst portion where severe deterioration occurs and the discharge gas forms a turbulent flow in the gas conduits.
Thus, the turbulent flow zone length Lb is selected from the range of 240 to 480 mm, corresponding to the "a" value of 3 to 6.
[0052]
<Summary of the Preliminary Tests>
On the basis of the aforementioned test results, the length of the turbulent flow zone of a honeycomb NO, removal catalyst can be represented by the following equation:
[0053]
[F6]
Lb = a (Ly/Lys) = 22eo.o35(Ly.Uin) (A) [0054]
(wherein "a" is a constant falling within a range of 3 to 6, when the aperture size (Ly) is 6 mm and the gas inflow rate 17.
is 6 m/s) [0055]
According to the method of the present invention, a first test piece, which is a catalyst portion having a length longer than the length of the turbulent flow zone; i.e., a length covering a turbulent flow zone and at least a portion of a laminar flow zone on the downstream side, is provided, the first test piece is subjected to a first NO,, removal test (performance evaluation of the turbulent flow zone and the laminar flow zone) ; a second NOX removal test is performed on a second test piece, which is obtained through removal of a portion corresponding to the turbulent flow zone; and, on the basis of the test results, catalytic performance of an actual NO, removal catalyst is assessed. More specifically, performance of the turbulent flow zone can be assessed through the second NO, removal test, and performance of a portion of the laminar flow zone can be assessed through the first NO, removal test. Through extrapolation of catalyst length to the actual length, performance of the entire laminar flow zone can be assessed. The test piece for exclusively evaluating the turbulent flow zone is preferably cut from the test piece for the first NOX removal test.
However, alternatively, the test piece may be cut from another, uncut catalyst sample. The first NO, removal test may be performed with a test piece including a portion of the laminar flow zone, or the test piece may contain the entirety of the laminar flow zone. In the latter case, extrapolation is not needed.
[0056]
<NO,t Removal Tests>
No particular limitation is imposed on the NO, removal tests carried out in the method of the present invention, and conventional test methods may be appropriately employed.
In the NO, removal tests, gas composition and gas inflow rate are preferably equivalent to those employed in an actual NO, removal apparatus. Even in the case where a gas inflow rate differing from that employed in the actual NO, removal apparatus is employed, as described hereinbelow, catalytic performance of the actual NO, removal apparatus can be assessed on the basis of the relationship between gas inflow rate and reacted NO,.
[0057]
In one exemplary catalytic performance assessment method, inlet and outlet NOX concentrations are determined, and percent NOX removal r] and percent NOX removal contribution of the catalyst are calculated on the basis of the following equation. This technique is based on the method disclosed in Japanese Patent Publication (kokoku) No.
7-47108.
[0058]
[F7]
= { (inlet NOX - outlet NOX) /(inlet NO,,) }x100 [0059]
In another catalytic performance assessment method, the inlet side and outlet side NO, concentrations and NH3 concentrations are determined, and, if required, the inlet 02 concentration is further determined. From the thus-obtained data, percent NO,s removal rj and percent NO, removal contribution of the catalyst are calculated. The percent NO, removal 11 is calculated on the basis of an inlet mole ratio (i.e., inlet NH3/inlet NOR) of the NO,, removal catalyst. The reason for taking the inlet mole ratio into consideration is as follows. NH3 is fed into an NO, removal apparatus in the vicinity of an NO,, removal catalyst on the upstream side in an amount proportional to that of the gas to be treated. The rate determining step of NOX removal reaction is a step of adsorbing an NH3 onto the catalyst. Therefore, determining NH3 concentrations on the inlet and outlet sides of the NO,, removal catalyst is most critical.
[0060]
When calculated on the basis of an inlet mole ratio, the percent NO, removal 11 may be calculated from NO, concentration or NH3 concentration. However, NH3-basis calculation provides percent NO, removal values of higher precision suitable for management.
[0061]
An exemplary procedure of deriving percent NOX removal fl will next be described. The percent NOX removal 11 is determined on the basis of the following equation employing NOX concentrations.
[0062]
[F8]
,l = { (inlet NO, - outlet NO.) / (inlet NO,) }x100x (evaluation mole ratio/inlet mole ratio) [0063]
As used herein, the term "evaluation mole ratio" refers to a mole ratio which is predetermined for the purpose of evaluating an NO, removal catalyst. The evaluation mole ratio may be predetermined to an arbitrary value; for example, 0.8, which is almost equal to a mole ratio typically employed for operating a power station.
[0064]
Although the percent NOx removal ti is determined on the basis of the equation employing NOx concentrations, a target catalyst can be evaluated on the basis of a percent NOx removal value actually reflecting the conditions of the catalyst, since the equation employs an inlet mole ratio. In general, since the percent NOx removal fl increases with NH3/NOX, the percent NOx removal i1 must be derived on the basis of the inlet mole ratio so as to evaluate a catalyst in an actual state.
[0065]
The percent NOx removal fl is also determined on the basis of the following equation employing NH3 concentrations.
[0066]
[F9]
1l = { (inlet NH3 - outlet NH3) /(inlet NH3 - outlet NH3 + outlet NOX)}x100x(evaluation mole ratio/inlet mole ratio) [0067]
Since the percent NOX removal i1 is determined on the basis of the equation employing NH3 concentrations, variation in the obtained percent NOX removal values is smaller as compared with the case in which the equation employing NOX
concentrations is used, which is advantageous. Thus, catalysts can be evaluated on the basis of percent removal values with smaller variation.
[0068]
<Test Example>
Percent NOX removal of a honeycomb NOX removal catalyst new product was determined in five divided portions; i.e., portions each having a length of 100 mm, from the inlet (0 mm) to a site at 500 mm. The percent NOX removal was determined under the following conditions: flow rate in the honeycomb of 6 m/s, SV value (only in the case of 0-100 mm portion test piece) of 59,600 m3N/m3h, AV value of 139.7 m3N/m2h, reaction gas temperature of 360 C, and mole ratio of 1Ø Under these conditions, flows NH3 and NO2 were equalized.
FIG. 5 shows the results.
As is clear from FIG. 5, NOX removal was found to be deteriorated from the site around the sustained turbulent flow distance (i.e., 300 to 400 mm).
[0069]
In addition to the above new catalyst product, a used NO, removal catalyst was tested in a similar manner. FIG. 6 shows the results.
[0070]
As is clear from FIG. 6, almost the same performance deterioration features as those of the new product were observed for the used NO, removal catalyst.
[0071]
<Example 1>
A first test piece (600 mm) was cut from a used NOX
removal catalyst (original length: 770 mm), and the test piece was subjected to a NOX removal test (a first NOX
removal test) . Subsequently, a second test piece (300 mm) was cut from the first test piece, and subjected to a similar NOX removal test.
[0072]
Table 2 and FIG. 7 show the results. As is clear from FIG. 7, reacted NOX concentrations and NH3 concentrations at catalyst sites of 300 mm and 600 mm were extrapolated to a catalyst site of 770 mm. Percent NO, removal at a catalyst site of 770 mm was determined from the extrapolated NO, concentration and NH3 concentration.
[0073]
[Table 2]
0 mm 0-300 mm 0-600 mm Extrap-olated Catalyst site 0 300 600 770 Reacted NOX 0 61 84 97 NOX removal 0.0% 20.3% 28.0% 32.3%
[0074]
<Example 2>
A first test piece (500 mm) was cut from an unused NO, removal catalyst, and the test piece was subjected to a NOX
removal test (a first NO, removal test) Subsequently, a second test piece (300 mm) was cut from the first test piece, and subjected to a similar NOX removal test.
Table 3 and FIG. 8 show the results. As is clear from FIG. 8, reacted NOX concentrations and NH3 concentrations at catalyst sites of 300 mm and 500 mm were extrapolated to catalyst sites of 770 mm and 800 mm. Percent NO, removal values at catalyst sites of 770 mm and 800 mm were determined from the extrapolated NOX concentrations and NH3 concentrations.
[0075]
Actual percent NOX removal was determined at catalyst sites of 770 mm and 800 mm so as to evaluate the extrapolated values. Table 3 shows the thus-determined percent NOX
removal values.
[0076]
As is clear from Table 3, the extrapolated values obtained according to the present invention and the actually determined values were found to be virtually equivalent.
[0077]
[Table 31 0 0-300 0-500 tra Ex- o Mea- - Mea-Ex- mm mm mm la ed sured tla era od sured Catalyst site 0 300 500 770 800 Reacted NOR 0 162 205 264 271 -NOR removal 0 54.0% 68.5% 88.0% 85.6% 90.2% 89.1%
[0078]
<Example 3>
Catalyst test pieces (300 mm and 500 mm) were evaluated in terms of amount of reacted NOR. The measurement was performed at 360 C and at mole ratios (inlet mole ratios (i.e., inlet NH3/inlet NOR)) of 0.6, 0.8, 1.0, and 1.2 and gas inflow rates of 6 m/s and 9 m/s.
[0079]
Table 4 and FIG. 9 show the results. As is clear from Table 4 and FIG. 9, a reacted NOR amount at a gas inflow rate of vl (reacted NOR (Vl)) and a reacted NOR amount at a gas inflow rate of v2 (reacted NOR(V2)) have the following relationship. Thus, when a gas inflow rate differing from that employed in an actual NOR removal apparatus is employed, catalytic performance can be determined by converting, on the basis of the following equation, the reacted NO, amount determined under the above conditions to the corresponding value at a gas inflow rate employed in the actual NO, removal apparatus.
[0080]
[F10]
(Reacted NO,(,,)/100-mm catalyst piece) x vl0.5 (reacted NO,{(V2)/100-mm catalyst piece) x v2o.5 [0081]
[Table 4]
Catalyst piece Mole ratio Gas inflow Gas inflow length rate 6 m/s rate 9 m/s 0.6 41 33 300 mm 0.8 50 40 1.0 55 44 1.2 56 46 0.6 15 13 500 mm 0.8 20 19 1.0 23 21 1.2 24 21 Industrial Applicability [0082]
The present invention can be suitably applied to assessment of performance of NOJZ removal catalysts employed in a flue gas NO,, removal apparatus installed in a facility such as a thermal power station and NO,, removal catalysts employed in boilers.
[0044]
[F3]
Lts = 22e0.035(Lys-Uins) (1) [0045]
When the aperture size Lys is 6 mm (constant value), the aperture size Ly (mm) is an arbitrary parameter, and Uin (m/s) represents a gas inflow rate, sustained turbulent flow distance Lt can be represented by the following formula (2), which is a general equation.
[0046]
[F4]
Lt = (Ly/Lys) =22e0035(Ly-Uin) (2) (0047) The simulation results were compared with the approximate length (optimum length) of the actual catalyst, the length being such that the flow of the exhaust gas fed into the gas conduits is straightened. Specifically, the relationship between sustained turbulent flow distance Lt and the optimum length of an actual catalyst (i.e., the length of a stained-portion of the catalyst (stain length), which is an index for detecting straightening) was investigated. As shown in FIG. 4, in an actual stage of the employed apparatus, turbulent flow is maintained over a portion of the catalyst having a distance longer than the sustained turbulent flow distance Lt, which is derived through simulation. One possible reason of this phenomenon is that inflow rate is varied and flow of the fluid is disturbed.
[0048]
Accordingly, in an actual catalyst unit, the distance from the inlet to a site where straightening starts (i.e., the length of the turbulent flow zone) must be determined from the above stain length and a certain safety length.
Specifically, equation (2) must be multiplied by a constant "a," and the length of the turbulent flow zone of the actual catalyst Lb is considered to be represented by the following equation (3). Note that "a" is a constant falling within a range of 3 to 6, when the aperture size of a honeycomb catalyst is 6 mm (pitch: 7 mm) and the gas inflow rate is 6 m/s.
[0049]
[F5]
Lb = a=Lt (3) [0050]
In the aforementioned Test Example 1, a honeycomb catalyst having an aperture size of 6 mm (pitch: 7 mm) was used at a gas inflow rate of 6 m/s. Thus, Lt is 80 mm. When the constant "a" is adjusted to about 3.8, Lt is about 300 mm, which corresponds to the length of a severely deteriorated portion of the catalyst, whereas when the constant "a" is adjusted to about 5.6, Lt is about 450 mm, which corresponds to the length of a portion of the catalyst including a portion exhibiting catalytic performance equivalent to that of a new catalyst product.
[0051]
In the same honeycomb catalyst, when "a" falls within a range of 3 to 6, the,turbulent flow zone length Lb falls within a range of about 240 to 480 mm. The range of Lb virtually coincides with a range of about 300 to 450 mm, which is considered to be a length of an actual NOX removal catalyst portion where severe deterioration occurs and the discharge gas forms a turbulent flow in the gas conduits.
Thus, the turbulent flow zone length Lb is selected from the range of 240 to 480 mm, corresponding to the "a" value of 3 to 6.
[0052]
<Summary of the Preliminary Tests>
On the basis of the aforementioned test results, the length of the turbulent flow zone of a honeycomb NO, removal catalyst can be represented by the following equation:
[0053]
[F6]
Lb = a (Ly/Lys) = 22eo.o35(Ly.Uin) (A) [0054]
(wherein "a" is a constant falling within a range of 3 to 6, when the aperture size (Ly) is 6 mm and the gas inflow rate 17.
is 6 m/s) [0055]
According to the method of the present invention, a first test piece, which is a catalyst portion having a length longer than the length of the turbulent flow zone; i.e., a length covering a turbulent flow zone and at least a portion of a laminar flow zone on the downstream side, is provided, the first test piece is subjected to a first NO,, removal test (performance evaluation of the turbulent flow zone and the laminar flow zone) ; a second NOX removal test is performed on a second test piece, which is obtained through removal of a portion corresponding to the turbulent flow zone; and, on the basis of the test results, catalytic performance of an actual NO, removal catalyst is assessed. More specifically, performance of the turbulent flow zone can be assessed through the second NO, removal test, and performance of a portion of the laminar flow zone can be assessed through the first NO, removal test. Through extrapolation of catalyst length to the actual length, performance of the entire laminar flow zone can be assessed. The test piece for exclusively evaluating the turbulent flow zone is preferably cut from the test piece for the first NOX removal test.
However, alternatively, the test piece may be cut from another, uncut catalyst sample. The first NO, removal test may be performed with a test piece including a portion of the laminar flow zone, or the test piece may contain the entirety of the laminar flow zone. In the latter case, extrapolation is not needed.
[0056]
<NO,t Removal Tests>
No particular limitation is imposed on the NO, removal tests carried out in the method of the present invention, and conventional test methods may be appropriately employed.
In the NO, removal tests, gas composition and gas inflow rate are preferably equivalent to those employed in an actual NO, removal apparatus. Even in the case where a gas inflow rate differing from that employed in the actual NO, removal apparatus is employed, as described hereinbelow, catalytic performance of the actual NO, removal apparatus can be assessed on the basis of the relationship between gas inflow rate and reacted NO,.
[0057]
In one exemplary catalytic performance assessment method, inlet and outlet NOX concentrations are determined, and percent NOX removal r] and percent NOX removal contribution of the catalyst are calculated on the basis of the following equation. This technique is based on the method disclosed in Japanese Patent Publication (kokoku) No.
7-47108.
[0058]
[F7]
= { (inlet NOX - outlet NOX) /(inlet NO,,) }x100 [0059]
In another catalytic performance assessment method, the inlet side and outlet side NO, concentrations and NH3 concentrations are determined, and, if required, the inlet 02 concentration is further determined. From the thus-obtained data, percent NO,s removal rj and percent NO, removal contribution of the catalyst are calculated. The percent NO, removal 11 is calculated on the basis of an inlet mole ratio (i.e., inlet NH3/inlet NOR) of the NO,, removal catalyst. The reason for taking the inlet mole ratio into consideration is as follows. NH3 is fed into an NO, removal apparatus in the vicinity of an NO,, removal catalyst on the upstream side in an amount proportional to that of the gas to be treated. The rate determining step of NOX removal reaction is a step of adsorbing an NH3 onto the catalyst. Therefore, determining NH3 concentrations on the inlet and outlet sides of the NO,, removal catalyst is most critical.
[0060]
When calculated on the basis of an inlet mole ratio, the percent NO, removal 11 may be calculated from NO, concentration or NH3 concentration. However, NH3-basis calculation provides percent NO, removal values of higher precision suitable for management.
[0061]
An exemplary procedure of deriving percent NOX removal fl will next be described. The percent NOX removal 11 is determined on the basis of the following equation employing NOX concentrations.
[0062]
[F8]
,l = { (inlet NO, - outlet NO.) / (inlet NO,) }x100x (evaluation mole ratio/inlet mole ratio) [0063]
As used herein, the term "evaluation mole ratio" refers to a mole ratio which is predetermined for the purpose of evaluating an NO, removal catalyst. The evaluation mole ratio may be predetermined to an arbitrary value; for example, 0.8, which is almost equal to a mole ratio typically employed for operating a power station.
[0064]
Although the percent NOx removal ti is determined on the basis of the equation employing NOx concentrations, a target catalyst can be evaluated on the basis of a percent NOx removal value actually reflecting the conditions of the catalyst, since the equation employs an inlet mole ratio. In general, since the percent NOx removal fl increases with NH3/NOX, the percent NOx removal i1 must be derived on the basis of the inlet mole ratio so as to evaluate a catalyst in an actual state.
[0065]
The percent NOx removal fl is also determined on the basis of the following equation employing NH3 concentrations.
[0066]
[F9]
1l = { (inlet NH3 - outlet NH3) /(inlet NH3 - outlet NH3 + outlet NOX)}x100x(evaluation mole ratio/inlet mole ratio) [0067]
Since the percent NOX removal i1 is determined on the basis of the equation employing NH3 concentrations, variation in the obtained percent NOX removal values is smaller as compared with the case in which the equation employing NOX
concentrations is used, which is advantageous. Thus, catalysts can be evaluated on the basis of percent removal values with smaller variation.
[0068]
<Test Example>
Percent NOX removal of a honeycomb NOX removal catalyst new product was determined in five divided portions; i.e., portions each having a length of 100 mm, from the inlet (0 mm) to a site at 500 mm. The percent NOX removal was determined under the following conditions: flow rate in the honeycomb of 6 m/s, SV value (only in the case of 0-100 mm portion test piece) of 59,600 m3N/m3h, AV value of 139.7 m3N/m2h, reaction gas temperature of 360 C, and mole ratio of 1Ø Under these conditions, flows NH3 and NO2 were equalized.
FIG. 5 shows the results.
As is clear from FIG. 5, NOX removal was found to be deteriorated from the site around the sustained turbulent flow distance (i.e., 300 to 400 mm).
[0069]
In addition to the above new catalyst product, a used NO, removal catalyst was tested in a similar manner. FIG. 6 shows the results.
[0070]
As is clear from FIG. 6, almost the same performance deterioration features as those of the new product were observed for the used NO, removal catalyst.
[0071]
<Example 1>
A first test piece (600 mm) was cut from a used NOX
removal catalyst (original length: 770 mm), and the test piece was subjected to a NOX removal test (a first NOX
removal test) . Subsequently, a second test piece (300 mm) was cut from the first test piece, and subjected to a similar NOX removal test.
[0072]
Table 2 and FIG. 7 show the results. As is clear from FIG. 7, reacted NOX concentrations and NH3 concentrations at catalyst sites of 300 mm and 600 mm were extrapolated to a catalyst site of 770 mm. Percent NO, removal at a catalyst site of 770 mm was determined from the extrapolated NO, concentration and NH3 concentration.
[0073]
[Table 2]
0 mm 0-300 mm 0-600 mm Extrap-olated Catalyst site 0 300 600 770 Reacted NOX 0 61 84 97 NOX removal 0.0% 20.3% 28.0% 32.3%
[0074]
<Example 2>
A first test piece (500 mm) was cut from an unused NO, removal catalyst, and the test piece was subjected to a NOX
removal test (a first NO, removal test) Subsequently, a second test piece (300 mm) was cut from the first test piece, and subjected to a similar NOX removal test.
Table 3 and FIG. 8 show the results. As is clear from FIG. 8, reacted NOX concentrations and NH3 concentrations at catalyst sites of 300 mm and 500 mm were extrapolated to catalyst sites of 770 mm and 800 mm. Percent NO, removal values at catalyst sites of 770 mm and 800 mm were determined from the extrapolated NOX concentrations and NH3 concentrations.
[0075]
Actual percent NOX removal was determined at catalyst sites of 770 mm and 800 mm so as to evaluate the extrapolated values. Table 3 shows the thus-determined percent NOX
removal values.
[0076]
As is clear from Table 3, the extrapolated values obtained according to the present invention and the actually determined values were found to be virtually equivalent.
[0077]
[Table 31 0 0-300 0-500 tra Ex- o Mea- - Mea-Ex- mm mm mm la ed sured tla era od sured Catalyst site 0 300 500 770 800 Reacted NOR 0 162 205 264 271 -NOR removal 0 54.0% 68.5% 88.0% 85.6% 90.2% 89.1%
[0078]
<Example 3>
Catalyst test pieces (300 mm and 500 mm) were evaluated in terms of amount of reacted NOR. The measurement was performed at 360 C and at mole ratios (inlet mole ratios (i.e., inlet NH3/inlet NOR)) of 0.6, 0.8, 1.0, and 1.2 and gas inflow rates of 6 m/s and 9 m/s.
[0079]
Table 4 and FIG. 9 show the results. As is clear from Table 4 and FIG. 9, a reacted NOR amount at a gas inflow rate of vl (reacted NOR (Vl)) and a reacted NOR amount at a gas inflow rate of v2 (reacted NOR(V2)) have the following relationship. Thus, when a gas inflow rate differing from that employed in an actual NOR removal apparatus is employed, catalytic performance can be determined by converting, on the basis of the following equation, the reacted NO, amount determined under the above conditions to the corresponding value at a gas inflow rate employed in the actual NO, removal apparatus.
[0080]
[F10]
(Reacted NO,(,,)/100-mm catalyst piece) x vl0.5 (reacted NO,{(V2)/100-mm catalyst piece) x v2o.5 [0081]
[Table 4]
Catalyst piece Mole ratio Gas inflow Gas inflow length rate 6 m/s rate 9 m/s 0.6 41 33 300 mm 0.8 50 40 1.0 55 44 1.2 56 46 0.6 15 13 500 mm 0.8 20 19 1.0 23 21 1.2 24 21 Industrial Applicability [0082]
The present invention can be suitably applied to assessment of performance of NOJZ removal catalysts employed in a flue gas NO,, removal apparatus installed in a facility such as a thermal power station and NO,, removal catalysts employed in boilers.
Claims (7)
1. A method of testing a honeycomb-form NO x removal catalyst for use in a flue gas NO x removal apparatus, the catalyst comprising gas conduits for feeding a discharge gas from an inlet to an outlet of each conduit and performing NO x removal on the sidewalls of the conduit, the method comprising providing a first test piece comprising a portion of the catalyst having a first length, the first length comprising a turbulent flow zone sustaining turbulent flow and where a gas to be treated is fed into the gas conduits from the inlet and at least a portion of a laminar flow zone downstream of the turbulent flow zone where transition from turbulent flow and laminar flow occurs;
performing a first NO x removal test with the first test piece;
subsequently, performing a second NO x removal test with a second test piece, which is obtained by cutting out a second length of a catalyst portion covering the turbulent flow zone; and determining on the basis of test results, a catalytic performance of the turbulent flow zone and the laminar flow zone, whereby catalytic performance of the NO x removal catalyst is obtained.
performing a first NO x removal test with the first test piece;
subsequently, performing a second NO x removal test with a second test piece, which is obtained by cutting out a second length of a catalyst portion covering the turbulent flow zone; and determining on the basis of test results, a catalytic performance of the turbulent flow zone and the laminar flow zone, whereby catalytic performance of the NO x removal catalyst is obtained.
2. A method of testing a honeycomb-form NO x removal catalyst according to claim 1, wherein the turbulent flow zone has a length Lb (mm) represented by equation (A):
Lb = a (Ly/Lys) .cndot.22e0 035(Ly Uin) (A) wherein Uin (m/s) represents a gas inflow rate, the aperture size Ly (mm) is an arbitrary value, Lys is an aperture size of 6 mm (constant value), and "a" is a constant falling within a range of 3 to 6, when the aperture size (Ly) is 6 mm and the gas inflow rate is 6 m/s.
Lb = a (Ly/Lys) .cndot.22e0 035(Ly Uin) (A) wherein Uin (m/s) represents a gas inflow rate, the aperture size Ly (mm) is an arbitrary value, Lys is an aperture size of 6 mm (constant value), and "a" is a constant falling within a range of 3 to 6, when the aperture size (Ly) is 6 mm and the gas inflow rate is 6 m/s.
3. A method of testing a honeycomb-form NO x removal catalyst according to claim 1 or 2, wherein the first or second NO x removal test is performed while a model gas having a composition simulating the gas treated in an actual NO x removal apparatus is fed at a gas inflow rate equivalent to that employed in an actual NO x removal apparatus, thereby determining catalyst performance.
4. A method of testing a honeycomb-form NO x removal catalyst according to claim 1 or 2, wherein the first or second NO x removal test is performed while a model gas having a composition simulating the gas treated in an actual NO x removal apparatus is fed at a flow rate differing from that employed in an actual NO, removal apparatus, thereby determining catalyst performance in consideration of the relationship between gas inflow rate and reacted NO x.
5. A method of testing a honeycomb-form NO x removal catalyst according to any of claims 1 to 4, wherein the first or second NO x removal test comprises determining NO x concentrations on the inlet and outlet sides of respective test pieces; determining NH3 concentrations on the inlet and outlet sides of respective test pieces; and determining percent NO x removal .eta. on the basis of an inlet mole ratio inlet NH3 inlet NO x.
6. A method of testing a honeycomb-form NO x removal catalyst according to claim 5, wherein the percent NO x removal .eta. is determined on the basis of NH3 concentrations.
7. A method of testing a honeycomb-form NO x removal catalyst according to claim 6, wherein the percent NO x removal n is determined on the basis of the following equation:
[F2]
.eta. = {(inlet NH3 - outlet NH3)/( inlet NH3-outlet NH3 + outlet NO x) } x 100x (evaluation mole ratio/inlet mole ratio).
[F2]
.eta. = {(inlet NH3 - outlet NH3)/( inlet NH3-outlet NH3 + outlet NO x) } x 100x (evaluation mole ratio/inlet mole ratio).
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| JP2004-190106 | 2004-06-28 | ||
| JP2004190106 | 2004-06-28 | ||
| PCT/JP2005/011381 WO2006001283A1 (en) | 2004-06-28 | 2005-06-21 | Method of testing denitration catalyst |
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| CA2571044C true CA2571044C (en) | 2010-10-26 |
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| US (1) | US7759122B2 (en) |
| EP (1) | EP1762844B1 (en) |
| JP (1) | JP4425275B2 (en) |
| KR (1) | KR100801237B1 (en) |
| CN (1) | CN1977162B (en) |
| CA (1) | CA2571044C (en) |
| DK (1) | DK1762844T3 (en) |
| PL (1) | PL1762844T3 (en) |
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| WO (1) | WO2006001283A1 (en) |
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| KR100616295B1 (en) * | 2002-12-27 | 2006-08-28 | 쥬코쿠 덴료쿠 가부시키 가이샤 | Method for producing honeycomb catalyst, method for producing denitration catalyst of denitration device, and method for producing exhaust gas denitration device |
| CN101109742B (en) * | 2007-08-24 | 2011-05-18 | 中电投远达环保工程有限公司 | Method for testing and analyzing warehouse separated type denitrated catalyzer |
| JP6215050B2 (en) * | 2013-12-27 | 2017-10-18 | 株式会社堀場製作所 | Catalyst evaluation system |
| CN103969315A (en) * | 2014-05-09 | 2014-08-06 | 南通亚泰船舶工程有限公司 | Denitration catalyst detection device and method |
| CN104297008A (en) * | 2014-10-11 | 2015-01-21 | 苏州华瑞能泰发电技术有限公司 | Denitration device potential assessment and prediction method based on field performance tests |
| CN105572291A (en) * | 2015-12-17 | 2016-05-11 | 云南电网有限责任公司电力科学研究院 | Catalyst activity detection method for boiler denitrification system |
| JP6428964B1 (en) * | 2017-12-28 | 2018-11-28 | 中国電力株式会社 | Denitration catalyst degradation evaluation method |
| CN109884242A (en) * | 2019-03-21 | 2019-06-14 | 青岛大学 | A kind of test device and evaluation method based on catalyst load filtrate denitration effect |
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| US4771029A (en) * | 1987-05-18 | 1988-09-13 | W. R. Grace & Co.-Conn | Monolith washcoat having optimum pore structure and optimum method of designing the washcoat |
| JP2635664B2 (en) | 1988-03-29 | 1997-07-30 | バブコツク日立株式会社 | Evaluation method of denitration catalyst |
| JPH0747108B2 (en) | 1991-05-14 | 1995-05-24 | 九州電力株式会社 | Catalyst management method for flue gas denitration equipment at thermal power plants |
| JP3246757B2 (en) | 1991-11-06 | 2002-01-15 | 三菱化学株式会社 | Nitrogen oxide removal catalyst |
| JPH06319951A (en) | 1993-05-14 | 1994-11-22 | Babcock Hitachi Kk | Method and apparatus for cleaning exhaust gas |
| EP0652435A3 (en) * | 1993-11-04 | 1996-11-20 | Siemens Ag | Sensor for determining the gradient of a concentration. |
| US5693295A (en) * | 1996-01-16 | 1997-12-02 | General Motors Corporation | Catalytic converter |
| US5972254A (en) * | 1996-12-06 | 1999-10-26 | Sander; Matthew T. | Ultra-thin prestressed fiber reinforced aerogel honeycomb catalyst monoliths |
| DE19736233C2 (en) * | 1997-08-20 | 2001-03-29 | Siemens Ag | Procedure for checking a catalyst |
| US6120580A (en) * | 1998-04-15 | 2000-09-19 | Hera, Llc | Method for testing systems designed for NOx reduction in the combustion of carbonaceous fuels |
| US6195986B1 (en) * | 1999-06-21 | 2001-03-06 | Ford Global Technologies, Inc. | Method and system for monitoring a catalytic converter |
| DE19931007C2 (en) * | 1999-07-06 | 2001-10-18 | Daimler Chrysler Ag | Method and device for determining the storage state of an ammonia-storing SCR catalytic converter |
| WO2001028665A1 (en) | 1999-10-15 | 2001-04-26 | Abb Lummus Global, Inc. | Conversion of nitrogen oxides in the presence of a catalyst supported of a mesh-like structure |
| JP4153658B2 (en) * | 2000-11-28 | 2008-09-24 | 三菱重工業株式会社 | NOx and NH3 simultaneous analysis apparatus and method |
| US6803236B2 (en) * | 2001-08-10 | 2004-10-12 | Delphi Technologies, Inc. | Diagnostic system for monitoring catalyst performance |
| JP4079414B2 (en) * | 2002-04-03 | 2008-04-23 | 三菱重工業株式会社 | Nitrogen oxide processing apparatus and nitrogen oxide processing method |
| JP4077659B2 (en) | 2002-05-23 | 2008-04-16 | 財団法人電力中央研究所 | Method for predicting catalyst life in combustion equipment |
| JP4288574B2 (en) | 2002-06-14 | 2009-07-01 | 中国電力株式会社 | Denitration catalyst management apparatus and denitration catalyst management method for denitration apparatus |
| KR100601054B1 (en) * | 2002-06-14 | 2006-07-19 | 쥬코쿠 덴료쿠 가부시키 가이샤 | APPARATUS FOR MONITORING NOx REMOVAL CATALYST OF DENITRIZER AND METHOD OF MONITORING NOx REMOVAL CATALYST |
| JP3935417B2 (en) | 2002-11-01 | 2007-06-20 | 中国電力株式会社 | Denitration catalyst management method and denitration catalyst management apparatus |
| KR100616295B1 (en) * | 2002-12-27 | 2006-08-28 | 쥬코쿠 덴료쿠 가부시키 가이샤 | Method for producing honeycomb catalyst, method for producing denitration catalyst of denitration device, and method for producing exhaust gas denitration device |
| WO2005056165A1 (en) * | 2003-12-11 | 2005-06-23 | The Chugoku Electric Power Co.,Inc. | Method for restoring performance capabilities of exhaust gas treatment apparatus |
| US7635593B2 (en) * | 2004-05-14 | 2009-12-22 | Fossil Energy Research Corp. (Ferco) | In-line localized monitoring of catalyst activity in selective catalytic NOx reduction systems |
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| PL1762844T3 (en) | 2015-03-31 |
| EP1762844A1 (en) | 2007-03-14 |
| EP1762844A4 (en) | 2009-04-01 |
| CN1977162A (en) | 2007-06-06 |
| US20070243619A1 (en) | 2007-10-18 |
| WO2006001283A1 (en) | 2006-01-05 |
| TWI277439B (en) | 2007-04-01 |
| US7759122B2 (en) | 2010-07-20 |
| CA2571044A1 (en) | 2006-01-05 |
| KR20070030234A (en) | 2007-03-15 |
| CN1977162B (en) | 2011-02-16 |
| EP1762844B1 (en) | 2014-09-10 |
| DK1762844T3 (en) | 2014-12-15 |
| KR100801237B1 (en) | 2008-02-11 |
| TW200605950A (en) | 2006-02-16 |
| JPWO2006001283A1 (en) | 2008-04-17 |
| JP4425275B2 (en) | 2010-03-03 |
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