Background technology
Normal containing a large amount of dust and nitrogen oxide in industrial furnace gas, a typical example and coal-fired plant boiler furnace gas, the nitrogen oxide contained by it is the main cause of facilitating acid rain to be formed, and also containing the dust of tens of grams in general often liter of coal-fired plant boiler furnace gas.The usual method taked for the purification of the such as industrial furnace gas of the contour dust of coal-fired plant boiler furnace gas and amount of nitrogen oxides is: first furnace gas is introduced SCR reactor (also needs to inject reducing agent in furnace gas in process furnace gas being introduced SCR reactor, this reducing agent is generally ammoniacal liquor) thus be harmless nitrogen gas by reduction of nitrogen oxide, realize furnace gas denitration purification, then the furnace gas after denitration is introduced electric cleaner to remove the dust in furnace gas, then discharge after the gas after dedusting is introduced desulfurizing tower desulfurizing and purifying.Said term " SCR " refers to Selective Catalytic Reduction, i.e. SCR.
Catalyst in above-mentioned SCR reactor is the key factor affecting the overall denitration effect of SCR system.The SCR catalyst of initial exploitation is graininess, then mainly adopts cellular or tabular catalyst at present.Honeycombed catalyst and tabular catalyst are all placed with numerous checkerwork cell passed through for furnace gas, the large I of these checkerwork cells is selected according to the concentration of dust in furnace gas and size, during use, furnace gas flows to the opposite side of catalyst by the passage be made up of these checkerwork cells from the side of catalyst, furnace gas contacts with the catalytic active substance on checkerwork cell inwall therebetween, thus is harmless nitrogen gas by the reduction of nitrogen oxide in furnace gas.Above-mentioned honeycombed catalyst and tabular catalyst are generally made up of carrier and catalytic active layer, wherein carrier is first made into cellular or tabular (general employing is extruded), and then on carrier, adhere to the catalytic active layer be made up of catalytic active substance.
Although the large I of the checkerwork cell of honeycombed catalyst and tabular catalyst is selected according to the concentration of dust in furnace gas and size, still exist in actual use the problem that blocks by dust.In addition, because SCR catalyst directly contacts with the furnace gas of high dustiness, therefore easily cause catalytic active substance poisoning, service life shortens.In addition, employ electric cleaner in said method to remove the dust in furnace gas, but by electric precipitation, there is the selective factors such as feature of gathering dust and affect the problem also often occurring that electric cleaner exit gas dustiness exceeds standard.Therefore, the purification techniques for the current such as industrial furnace gas of the contour dust of coal-fired plant boiler furnace gas and amount of nitrogen oxides need further improvement.
Present invention applicant is called Chinese patent application file (the publication number CN104492189A of " industrial furnace gas dedusting denitrification integral processing method and special equipment " in name, call reference paper in the following text) in provide and can carry out the industrial furnace gas dedusting denitrification integral processing method of dedusting and denitration and special equipment to industrial furnace gas simultaneously and include but not limited to the filtration catalytic element that can apply in this industrial furnace gas dedusting denitrification integral processing method and preparation method thereof, to realize the double action treating medium high-efficiency filtering and purifying and catalytic reaction.The filtration catalytic element provided in this patent document has a porous complex, this porous complex comprises porous matrix and catalytic active layer, described porous matrix is made up of sintering diamond bit or sintered ceramic porous material, described catalytic active layer is attached to porous matrix hole surface and is made up of catalytic active substance, in addition porous complex also comprises intermediate layer, described intermediate layer is made up of the nano particle at porous matrix surface sediment, and described catalytic active layer is attached to porous matrix hole surface by intermediate layer.For this filtration catalytic element, because intermediate layer is made up of the nano particle at porous matrix surface sediment, therefore the hole surface of the surface ratio porous matrix in intermediate layer is much coarse, substantially increase the specific area of porous matrix thus, all can significantly improve with the uniformity coefficient of the content and setting that make catalytic active substance in porous complex, improve catalytic reaction rate.In addition, additionally provide filtration catalytic element in above-mentioned patent document and form as concrete structure when industrial furnace gas being had to filtration and a function element of SCR denitration catalysis double action and material, and the preparation method of this filtration catalytic element.
The present inventor's follow-up study finds, in the preparation process of the filtration catalytic element of reference paper, colloidal sol as intermediate layer material source is first impregnated in porous matrix, then the collosol and gel in porous matrix is made, again the porous matrix of the described gel of attachment is heat-treated, gel conversion is made to be nano particle, and then form that the process in intermediate layer can not make to combine between intermediate layer and porous matrix very firm, the risk dropped from porous matrix in use intermediate layer deposited by this filtration catalytic element; Further, affect by factors such as porous matrix surface tension, colloidal sol not easily soaks in whole porous matrix comprehensively, limits the load capacity of catalytic active substance.
Summary of the invention
Technical problem to be solved by this invention be to provide a kind of treat filtrate have catalytic reaction effect filter element, a kind of there is the filter element of denitration catalyst effect and the preparation method of a kind of denitration catalyst filter element and this several filter element above-mentioned, between the intermediate layer of these filter elements and porous matrix, all there is higher adhesion.
Treat the filter element that filtrate has catalytic reaction effect, comprise a porous complex, this porous complex comprises: porous matrix, and described porous matrix is made up of sintering diamond bit or sintered ceramic porous material and has the network hole of 3 D stereo connection; Intermediate layer, described intermediate layer is attached to the hole surface of porous matrix and increases porous matrix hole surface roughness; Catalytic active layer, described catalytic active layer is that carrier is attached to the hole surface of porous matrix and is made up of catalytic active substance with intermediate layer; Described intermediate layer comprises the first intermediate layer, and the precursor substance in this first intermediate layer or the first intermediate layer is interior when sintering the described porous matrix of formation to be born on this porous matrix; Described intermediate layer also comprises the second intermediate layer, and described second intermediate layer is formed at first intermediate layer on by covering mode outward again after the first intermediate layer is formed; Adhesion between described first intermediate layer and the second intermediate layer is greater than the first intermediate layer or the adhesion between the second intermediate layer and porous matrix.
The first intermediate layer or the adhesion between the second intermediate layer and porous matrix is greater than for making the adhesion between the first intermediate layer and the second intermediate layer, general way the first intermediate layer and the second intermediate layer is made up of material of the same race and is made by mode of heating the first intermediate layer and the second intermediate layer moltenly be integrated (can comprise the link of heating when covering the second intermediate layer outside, thus make the first intermediate layer and the second intermediate layer is molten is integrated).And in order to make, the precursor substance in the first intermediate layer or the first intermediate layer is interior when sintering the described porous matrix of formation to be born on this porous matrix, general way is that described porous matrix is made up of powder sintered metal porous material or powder sintered ceramic porous material, and the precursor substance in described first intermediate layer or the first intermediate layer is by the way of the powder sintering of blending in the powder stock of this porous matrix of preparation.
The first above-mentioned intermediate layer and the second intermediate layer are successively formed at porous matrix hole surface by different modes, wherein because the precursor substance in the first intermediate layer or the first intermediate layer is interiorly born on this porous matrix when sintering and forming described porous matrix, therefore one is in fact sintered between the first intermediate layer (or the precursor substance in the first intermediate layer) and porous matrix, make, between the first intermediate layer of final formation and porous matrix, there is very strong adhesion, also just improve the adhesion between intermediate layer and porous matrix, well improve the problem that in filter element use procedure, drop from porous matrix in intermediate layer, described second intermediate layer is formed at first intermediate layer on by covering mode outward again after the first intermediate layer is formed, because the first intermediate layer superposes with the mutual of the second intermediate layer, the coverage of intermediate layer in porous matrix is increased, improve the load capacity of subsequent catalyst active material, improve the catalytic performance of filter element further.
Treat the preparation method that filtrate has the filter element of catalytic reaction effect, comprise following link: A. adopts powder metallurgic method to prepare porous matrix, containing the first powder for sintering formation porous matrix and the second powder for sintering formation first intermediate layer or the first intermediate layer precursor substance when sintering formation porous matrix in the powder stock preparing this porous matrix, the average grain diameter of the second powder is less than the average grain diameter of the first powder, after getting above-mentioned powder stock ready, shaping and sintering is carried out to it, thus obtain porous matrix and form the precursor substance in the first intermediate layer or the first intermediate layer at the hole surface of porous matrix, if be B. formed as the first intermediate layer in above-mentioned A link, enter following C link, if be formed as the precursor substance in the first intermediate layer in above-mentioned A link, then carry out entering following C link again after chemical treatment makes it to change the first intermediate layer into the precursor substance in the first intermediate layer, C. the colloidal sol as the second intermediate layer material source is configured, again by described sol impregnation in porous matrix, then make the collosol and gel in porous matrix, then to attachment described gel porous matrix heat-treat, make gel conversion be nano particle, and then form the second intermediate layer, D. configure catalytic active substance precursor solution, more described precursor solution is impregnated in the porous matrix in attachment intermediate layer, then the porous matrix being attached with precursor solution is heat-treated, form catalytic active layer on the intermediate layer.
There is the filter element of catalytic reaction effect according to above-mentioned filtrate for the treatment of and treat the preparation method that filtrate has the filter element of catalytic reaction effect, in the present invention, catalytic active layer take intermediate layer as carrier, and " intermediate layer " namely in the present invention acts on " catalyst carrier " that be equivalent in existing loaded catalyst.The more employing oxide of catalyst carrier of existing loaded catalyst, such as TiO
2, Al
2o
3, ZrO
2, SiO
2deng, if the first intermediate layer also includes at least one oxide, both may be then the oxidate powder that corresponding element powder also may be corresponding with regard to this oxide in the second powder, if element powder, then this element powder to be sintered when sintering and forming porous matrix the oxide forming correspondence to be difficult in practice accomplish, even if inherently oxidate powder in the second powder, this oxidate powder also may at high temperature react when sintering and forming porous matrix, therefore, when the first intermediate layer includes at least one oxide, if the first intermediate layer completely (what namely obtain is the precursor substance in the first intermediate layer) can not be obtained in above-mentioned A link, all should carry out chemical treatment in above-mentioned B link makes the precursor substance in the first intermediate layer change the first intermediate layer into, and chemical treatment now generally should be oxidizing roasting.
Said method can not only prepare foregoingly treats the filter element that filtrate has catalytic reaction effect, thus ensures the adhesion between intermediate layer and porous matrix, increases the coverage of intermediate layer in porous matrix; Meanwhile, the average grain diameter due to the second powder is less than the average grain diameter of the first powder, the first interlayer surfaces of formation can be made more coarse, be conducive to the raising of catalytic performance; The second intermediate layer that the method obtains is made up of the nano particle piled up on the first intermediate layer, can significantly improve the load capacity of catalytic active substance, promotes catalytic effect.
What have higher adhesion between intermediate layer and porous matrix treats the filter element that filtrate has catalytic reaction effect, comprise a porous complex, this porous complex comprises: porous matrix, described porous matrix by powder sintered metal porous material or by powder sintered ceramic porous material form and have 3 D stereo be communicated with network hole; Intermediate layer, described intermediate layer is attached to the hole surface of porous matrix and increases porous matrix hole surface roughness; Catalytic active layer, described catalytic active layer is that carrier is attached to the hole surface of porous matrix and is made up of catalytic active substance with intermediate layer; The precursor substance in described intermediate layer or intermediate layer sinter form described porous matrix time by the powder sintering of blending in the powder stock of this porous matrix of preparation in be born on this porous matrix.The intermediate layer of this filter element is not divided into the first intermediate layer and the second intermediate layer, but because the precursor substance in this intermediate layer or intermediate layer is interiorly born on this porous matrix when sintering and forming described porous matrix, therefore one is in fact sintered between intermediate layer (or the precursor substance in intermediate layer) and porous matrix, make, between the intermediate layer of final formation and porous matrix, there is very strong adhesion, also just improve the adhesion between intermediate layer and porous matrix, still improve the problem that in existing filter element use procedure, drop from porous matrix in intermediate layer.
There is the filter element of denitration catalyst effect, it is a kind of function element flue gas to filtration and denitration catalyst double action, comprise a porous complex, this porous complex comprises: porous matrix, and described porous matrix is made up of sintering diamond bit or sintered ceramic porous material and has the network hole of 3 D stereo connection; Intermediate layer, described intermediate layer is attached to the hole surface of porous matrix and increases porous matrix hole surface roughness; Catalytic active layer, described catalytic active layer is that carrier is attached to the hole surface of porous matrix and is made up of denitration catalyst active material with intermediate layer; Described intermediate layer comprises the first intermediate layer, and the precursor substance in this first intermediate layer or the first intermediate layer is interior when sintering the described porous matrix of formation to be born on this porous matrix; Described intermediate layer also comprises the second intermediate layer, and described second intermediate layer is formed at first intermediate layer on by covering mode outward again after the first intermediate layer is formed; Described first intermediate layer and the second intermediate layer are by TiO
2form.The above-mentioned filter element with denitration catalyst effect can be used in industrial furnace gas dedusting in reference paper and SCR denitration integral treatment method.
There is the preparation method of the filter element of denitration catalyst effect, comprise following link: A. adopts powder metallurgic method to prepare porous matrix, wherein, the powder stock preparing this porous matrix comprises the first powder for sintering formation porous matrix and the second powder for sintering formation first intermediate layer precursor substance when sintering and forming porous matrix, described first powder is the raw meal of Fe-Al dual alloy billet porous material, and the second powder is Ti and/or TiH
2powder, the particle diameter of the first powder is-100 ~+400 orders, particle diameter≤10 μm of the second powder, in powder stock, the weight percentage of the second powder is 1 ~ 10%, by the preparation method of Fe-Al dual alloy billet porous material, pressure forming and sintering are carried out to it after getting above-mentioned powder stock ready, obtain porous matrix after sintering and form at the hole surface of porous matrix the first intermediate layer precursor substance be made up of Ti substrate matter; B. carrying out oxidizing roasting to porous matrix makes the first intermediate layer precursor substance change into by TiO
2the first intermediate layer formed; C. the colloidal sol as the second intermediate layer material source is configured, again by described sol impregnation in porous matrix, then the collosol and gel in porous matrix is made, again the porous matrix of the described gel of attachment is heat-treated, gel conversion is made to be nano particle, and then forming the second intermediate layer, described second intermediate layer is by TiO
2nano particle is formed; D. configure catalytic active substance precursor solution, more described precursor solution is impregnated in the porous matrix in attachment intermediate layer, then the porous matrix being attached with precursor solution is heat-treated, described intermediate layer forms catalytic active layer.
Denitration catalyst filter element, it is a kind of function element flue gas to filtration and denitration catalyst double action, comprise a porous complex, this porous complex comprises: porous matrix, and described porous matrix is made up of sintering diamond bit or sintered ceramic porous material and has the network hole of 3 D stereo connection; Intermediate layer, described intermediate layer is attached to the hole surface of porous matrix and increases porous matrix hole surface roughness; Catalytic active layer, described catalytic active layer is that carrier is attached to the hole surface of porous matrix and is made up of denitration catalyst active material with intermediate layer; Described intermediate layer comprises the first intermediate layer, and the precursor substance in this first intermediate layer or the first intermediate layer is interior when sintering the described porous matrix of formation to be born on this porous matrix; Described intermediate layer also comprises the second intermediate layer, and described second intermediate layer is formed at first intermediate layer on by covering mode outward again after the first intermediate layer is formed; Described first intermediate layer and the second intermediate layer are by Al
2o
3form.This denitration catalyst filter element can be used in industrial furnace gas dedusting in reference paper and SCR denitration integral treatment method equally.
The preparation method of denitration catalyst filter element, comprise following link: A. adopts powder metallurgic method to prepare porous matrix, wherein, the powder stock preparing this porous matrix comprises the first powder for sintering formation porous matrix and the second powder for sintering formation first intermediate layer precursor substance when sintering and forming porous matrix, described first powder is the raw meal of Fe-Al dual alloy billet porous material, and the second powder is Al powder and/or Al
2o
3powder, the particle diameter of the first powder is-100 ~+400 orders, particle diameter≤10 μm of the second powder, in powder stock, the weight percentage of the second powder is 1 ~ 10%, by the preparation method of Fe-Al dual alloy billet porous material, pressure forming and sintering are carried out to it after getting above-mentioned powder stock ready, obtain porous matrix after sintering and form at the hole surface of porous matrix the first intermediate layer precursor substance be made up of Al substrate matter; B. carrying out oxidizing roasting to porous matrix makes the first intermediate layer precursor substance change into by Al
2o
3the first intermediate layer formed; C. the colloidal sol as the second intermediate layer material source is configured, again by described sol impregnation to porous matrix, then the collosol and gel in porous matrix is made, again the porous matrix of the described gel of attachment is heat-treated, gel conversion is made to be nano particle, and then forming the second intermediate layer, described second intermediate layer is by Al
2o
3nano particle is formed; D. configure catalytic active substance precursor solution, more described precursor solution is impregnated in the porous matrix in attachment intermediate layer, then the porous matrix being attached with precursor solution is heat-treated, described intermediate layer forms catalytic active layer.
Above-mentioned " having the filter element of denitration catalyst effect " and " denitration catalyst filter element " can regard as " treating the filter element that filtrate has catalytic reaction effect " provided by the invention two instantiations when using as SCR denitration catalysis.Described denitration catalyst filter element is compared with having the filter element of denitration catalyst effect, and both differences are the constitute difference in the first intermediate layer, the second intermediate layer; But their catalytic active layer all can by V
2o
5form or with V
2o
5for main component, with WO
3and MoO
3in at least one be auxiliary element mixture form; And their porous matrix all can be made up of Al series metal compounds base alloy porous material (the Fe-Al dual alloy billet porous material as resistance to elevated temperatures excellence).About the constitute in the first intermediate layer, the second intermediate layer, a kind of better mode is: the first intermediate layer and/or the second intermediate layer are made up of a multiple element compound, and this multiple element compound is primarily of TiO
2, Al
2o
3and SiO
2mix.The first intermediate layer be made up of above-mentioned the multiple element compound and/or the second intermediate layer have better architectural characteristic, mechanical strength, specific surface activity, can improve catalytic active layer surface texture and mechanical performance, are conducive to improving catalytic reaction effect.
Below in conjunction with the drawings and specific embodiments, the present invention will be further described.The aspect that the present invention adds and advantage will part provide in the following description, and part will become obvious from the following description, or be recognized by practice of the present invention.
Detailed description of the invention
4 kinds of denitration catalyst filter elements are prepared respectively below by way of 4 embodiments, these 4 kinds of denitration catalyst filter elements are all carry out filtering to coal-fired plant boiler furnace gas and carry out the function element of SCR denitration catalysis simultaneously, and the concrete installation and application about this denitration catalyst filter element can according to reference paper.
The microstructure of the filter element of embodiment 1 all as shown in Figure 1, it specifically comprises a porous complex 100, the average pore size of porous complex 100 is generally filtered needs according to concrete gas solid separation set 1 to 200 μm of scope, this porous complex 100 comprises: porous matrix 110, and described porous matrix 110 is made up of powder sintered metal porous material or powder sintered ceramic porous material and has the network hole 111 of 3 D stereo connection; Intermediate layer 120, described intermediate layer 120 is attached to the hole surface of porous matrix 110 and increases porous matrix 110 hole surface roughness (in Fig. 1, the surface of label " 111 " indication is the boundary face in porous matrix 110 and intermediate layer 120); Catalytic active layer 130, catalytic active layer 130 is attached to the hole surface of porous matrix 110 with intermediate layer 120 for carrier and is made up of denitration catalyst active material; Wherein, intermediate layer 120 comprises the first intermediate layer 121 and the second intermediate layer 122, the precursor substance in this first intermediate layer 121 or the first intermediate layer 121 is interior when sintering the described porous matrix 110 of formation to be born on this porous matrix 110, and the second intermediate layer 122 is formed at first intermediate layer 121 on by covering mode outward again after the first intermediate layer 121 is formed; In addition, porous complex 100 windward side is also attached with the rete 200 be made up of powder sintered metal porous material or powder sintered ceramic porous material, the average pore size of rete 200 is generally 1 to 100 μm (filtering needs according to concrete gas solid separation to set) and is less than the average pore size of porous complex 100.
Difference on the filter element of embodiment 2 to 3 and the filter arrangements of embodiment 1 is that rete 200 is not established in the windward side of porous complex 100.Difference on the filter element of embodiment 4 and the filter arrangements of embodiment 2 to 3 is that intermediate layer 120 is for single layer structure, is not divided into the first above-mentioned intermediate layer 121 and the second intermediate layer 122.
[embodiment 1]
1. the step of preparation process of denitration catalyst filter element
A. powder metallurgic method is adopted to prepare porous matrix 110, wherein, the powder stock preparing this porous matrix 100 comprises the first powder for sintering formation porous matrix 100 and the second powder for sintering formation first intermediate layer 121 precursor substance when sintering and forming porous matrix 100, described first powder is the raw meal of Fe-Al dual alloy billet porous material, the Al powder accounting for powder stock gross weight 20% is specifically comprised in this first powder, the Fe powder of 70%, the Cr powder of 8%, second powder specifically comprises the Ti powder accounting for powder stock gross weight 2%, the particle diameter of above-mentioned first powder is-100 ~+400 orders, particle diameter≤10 μm of the second powder, by the preparation method of Fe-Al dual alloy billet porous material, pressure forming and sintering are carried out to it after getting powder stock ready, shaping concrete employing cold isostatic compaction mode thus powder stock is pressed into the shape of filter element, pressure setting is 200MPa, sintering temperature controls at 1250 DEG C and is incubated 4 hours, room temperature is cooled to after sintering, testing this porous matrix 110 air flux is 264m
3/ m
2.h.kpa, average pore size is 55 μm, and normal temperature tension is 75MPa, porosity 42%.
B. film liquid is configured, specific practice is that powder is mixed high speed dispersion with binder solution, to be the aluminium powder 20% (weight) of 3 ~ 10 μm and particle diameter be that the Cr powder 10% (weight) of 5 ~ 15 μm mixes for iron powder 70% (weight) and particle diameter that wherein powder is 5 ~ 15 μm by particle diameter, binder solution is take PVB as solute, alcohol for solvent by 2% mass concentration configuration form, after the configuration of film liquid, the weight of powder is 40% of film liquid weight.The windward side of porous matrix 110 is covered the film liquid made and configure, and then carry out sintering to the porous matrix 110 of coherent film liquid and make film liquid change rete 200 into, the average pore size of rete 200 is 25 μm.
C. carry out oxidizing roasting to the porous matrix 110 of attachment rete 200, sintering temperature controls at 300 DEG C, and roasting time is 2 hours, thus the first intermediate layer 121 is changed into completely by TiO
2the first intermediate layer 121 formed;
D. the colloidal sol as the second intermediate layer 122 material source is prepared, be about to butyl titanate, alcohol and aqueous solution of nitric acid 2:10:1 mixing by volume, it is 4 that adjustment acid content controls pH value, colloidal sol is met the demands, then by described sol impregnation to attachment rete 200 porous matrix 110 in, at 105 DEG C, be incubated 2 hours after dipping, put into resistance furnace after there is stable gel and fire 4h at 450 DEG C, formed by TiO
2the second intermediate layer 122 that nano particle is formed;
E. ammonium paratungstate and ammonium metavanadate preparation catalytic active substance precursor solution is adopted, again described precursor solution is impregnated in the porous matrix 110 in attachment intermediate layer 120, then the porous matrix being attached with precursor solution is burnt in resistance furnace and heat-treat, 2h is incubated at 300 ~ 450 DEG C, described intermediate layer 120 forms catalytic active layer 130c
2. the result of use test of denitration catalyst filter element
Above-mentioned denitration catalyst filter element is loaded in integrated apparatus (see reference paper), and with the pipeline closed, the high-temperature furnace gas that coal-fired plant boiler economizer is got rid of is passed into the air inlet of integrated apparatus, make the furnace gas being mixed with reducing agent by filtration catalytic element, thus under the effect of filtration catalytic element 110, carrying out gas-solid isolated by filtration and the SCR denitration of furnace gas simultaneously, in the gas that integrated apparatus is discharged, dust content is at 4mg/Nm
3below, denitration rate is about 90%, and still can keep comparatively stable denitration rate after repeatedly carrying out pulse cleaning to filter element, use after a period of time by lower for filter element mounting or dismounting observe find catalytic active substance and porous matrix 100 adhesion condition good.
[embodiment 2]
1. the step of preparation process of denitration catalyst filter element
A. powder metallurgic method is adopted to prepare porous matrix 110, wherein, the powder stock preparing this porous matrix 100 comprises the first powder for sintering formation porous matrix 100 and the second powder for sintering formation first intermediate layer 121 or the first intermediate layer 121 precursor substance when sintering and forming porous matrix 100, described first powder is the raw meal of Fe-Al dual alloy billet porous material, the Al powder accounting for powder stock gross weight 22% is specifically comprised in this first powder, the Fe powder of 65%, the Cr powder of 8%, second powder specifically comprises the Al accounting for powder stock gross weight 5%
2o
3powder, the particle diameter of above-mentioned first powder is-100 ~+400 orders, particle diameter≤10 μm of the second powder, by the preparation method of Fe-Al dual alloy billet porous material, pressure forming and sintering are carried out to it after getting powder stock ready, shaping concrete employing cold isostatic compaction mode thus powder stock is pressed into the shape of filter element, pressure setting is 200MPa, and sintering temperature controls at 1250 DEG C and is incubated 4 hours, be cooled to room temperature after sintering, testing this porous matrix 110 air flux is 313m
3/ m
2.h.kpa, average pore size is 55 μm, and normal temperature tension is 75MPa, porosity 43%.
B. carry out oxidizing roasting to porous matrix 110, sintering temperature controls at 300 DEG C, and roasting time is 2 hours, thus the first intermediate layer 121 is changed into completely by Al
2o
3the first intermediate layer 121 formed;
C. the colloidal sol as the second intermediate layer 122 material source is prepared, by Al (NO
3)
3, the 2:10:1 mixing by volume of alcohol and aqueous solution of nitric acid, it is 4 that adjustment acid content controls pH value, colloidal sol is met the demands, then by described sol impregnation in porous matrix 110, at 105 DEG C, 2 hours are incubated after dipping, put into resistance furnace after there is stable gel and fire 1h at 450 DEG C, formed by Al
2o
3the second intermediate layer 122 that nano particle is formed;
D. ammonium paratungstate and ammonium metavanadate preparation catalytic active substance precursor solution is adopted, again described precursor solution is impregnated in the porous matrix 110 in attachment intermediate layer 120, then the porous matrix being attached with precursor solution is burnt in resistance furnace and heat-treat, at 300 ~ 450 DEG C, be incubated 2h, described intermediate layer 120 forms catalytic active layer 130c.
2. the result of use test of denitration catalyst filter element
Above-mentioned denitration catalyst filter element is loaded in integrated apparatus, and with the pipeline closed, the high-temperature furnace gas that coal-fired plant boiler economizer is got rid of is passed into the air inlet of integrated apparatus, make the furnace gas being mixed with reducing agent by filtration catalytic element, thus under the effect of filtration catalytic element 110, carrying out gas-solid isolated by filtration and the SCR denitration of furnace gas simultaneously, in the gas that integrated apparatus is discharged, dust content is at 10mg/Nm
3below, denitration rate is about 86%, and still can keep comparatively stable denitration rate after repeatedly carrying out pulse cleaning to filter element, use after a period of time by lower for filter element mounting or dismounting observe find catalytic active substance and porous matrix 100 adhesion condition good.
[embodiment 3]
1. the step of preparation process of denitration catalyst filter element
A. powder metallurgic method is adopted to prepare porous matrix 110, wherein, the powder stock preparing this porous matrix 100 comprises the first powder for sintering formation porous matrix 100 and the second powder for sintering formation first intermediate layer 121 or the first intermediate layer 121 precursor substance when sintering and forming porous matrix 100, described first powder is the raw meal of Fe-Al dual alloy billet porous material, the Al powder accounting for powder stock gross weight 20% is specifically comprised in this first powder, the Fe powder of 63% and the Cr powder of 8%, second powder specifically comprises the Ti powder accounting for powder stock gross weight 7%, the Al of 1.5%
2o
3powder and 0.5% SiO
2powder, the particle diameter of above-mentioned first powder is-100 ~+400 orders, particle diameter≤10 μm of the second powder, by the preparation method of Fe-Al dual alloy billet porous material, pressure forming and sintering are carried out to it after getting powder stock ready, shaping concrete employing cold isostatic compaction mode thus powder stock is pressed into the shape of filter element, pressure setting is 200MPa, and sintering temperature controls at 1250 DEG C and is incubated 4 hours, be cooled to room temperature after sintering, testing this porous matrix 110 air flux is 302m
3/ m
2.h.kpa, average pore size is 58 μm, and normal temperature tension is 75MPa, porosity 42%.
B. carry out oxidizing roasting to porous matrix 110, sintering temperature controls at 500 DEG C, and roasting time is 4 hours, thus the first intermediate layer 121 is changed into completely by TiO
2, Al
2o
3and SiO
2the first intermediate layer 121 formed;
C. the colloidal sol as the second intermediate layer 122 material source is prepared, by Al (NO
3)
3, butyl titanate, trimethyl silicane sodium alkoxide, the 1:8:1:40:5 mixing by volume of alcohol and aqueous solution of nitric acid, it is 3 that adjustment acid content controls pH value, colloidal sol is met the demands, then by described sol impregnation in porous matrix 110, at 105 DEG C, 2 hours are incubated after dipping, put into resistance furnace after there is stable gel and fire 1h at 450 DEG C, formed by TiO
2nano particle, Al
2o
3nano particle and SiO
2the second intermediate layer 122 that nano particle is formed;
D. ammonium paratungstate and ammonium metavanadate preparation catalytic active substance precursor solution is adopted, again described precursor solution is impregnated in the porous matrix 110 in attachment intermediate layer 120, then the porous matrix being attached with precursor solution is burnt in resistance furnace and heat-treat, at 300 ~ 450 DEG C, be incubated 2h, described intermediate layer 120 forms catalytic active layer 130c.
2. the result of use test of denitration catalyst filter element
Above-mentioned denitration catalyst filter element is loaded in integrated apparatus, and with the pipeline closed, the high-temperature furnace gas that coal-fired plant boiler economizer is got rid of is passed into the air inlet of integrated apparatus, make the furnace gas being mixed with reducing agent by filtration catalytic element, thus under the effect of filtration catalytic element 110, carrying out gas-solid isolated by filtration and the SCR denitration of furnace gas simultaneously, in the gas that integrated apparatus is discharged, dust content is at 8mg/Nm
3below, denitration rate is about 92%, and still can keep comparatively stable denitration rate after repeatedly carrying out pulse cleaning to filter element, use after a period of time by lower for filter element mounting or dismounting observe find catalytic active substance and porous matrix 100 adhesion condition good.
[embodiment 4]
1. the step of preparation process of denitration catalyst filter element
A. powder metallurgic method is adopted to prepare porous matrix 110, wherein, the powder stock preparing this porous matrix 100 comprises the first powder for sintering formation porous matrix 100 and the second powder for sintering formation intermediate layer or intermediate layer precursor substance when sintering and forming porous matrix 100, described first powder is the raw meal of Fe-Al dual alloy billet porous material, specifically comprise the Al powder, the Fe powder of 65%, the Cr powder of 8% that account for powder stock gross weight 22% in this first powder, the second powder specifically comprises the Al accounting for powder stock gross weight 5%
2o
3powder, the particle diameter of above-mentioned first powder is-100 ~+400 orders, particle diameter≤10 μm of the second powder, by the preparation method of Fe-Al dual alloy billet porous material, pressure forming and sintering are carried out to it after getting powder stock ready, shaping concrete employing cold isostatic compaction mode thus powder stock is pressed into the shape of filter element, pressure setting is 200MPa, and sintering temperature controls at 1250 DEG C and is incubated 4 hours, be cooled to room temperature after sintering, testing this porous matrix 110 air flux is 235m
3/ m
2.h.kpa, average pore size is 35 μm, and normal temperature tension is 65MPa, porosity 40%.
B. carry out oxidizing roasting to porous matrix 110, sintering temperature controls at 300 DEG C, and roasting time is 3 hours, thus intermediate layer is changed into completely by Al
2o
3the intermediate layer formed;
C. ammonium paratungstate and ammonium metavanadate preparation catalytic active substance precursor solution is adopted, again described precursor solution is impregnated in the porous matrix 110 in attachment intermediate layer 120, then the porous matrix being attached with precursor solution is burnt in resistance furnace and heat-treat, at 300 ~ 450 DEG C, be incubated 2h, described intermediate layer 120 forms catalytic active layer 130c.
2. the result of use test of denitration catalyst filter element
Above-mentioned denitration catalyst filter element is loaded in integrated apparatus, and with the pipeline closed, the high-temperature furnace gas that coal-fired plant boiler economizer is got rid of is passed into the air inlet of integrated apparatus, make the furnace gas being mixed with reducing agent by filtration catalytic element, thus under the effect of filtration catalytic element 110, carrying out gas-solid isolated by filtration and the SCR denitration of furnace gas simultaneously, in the gas that integrated apparatus is discharged, dust content is at 10mg/Nm
3below, denitration rate is about 78%, and still can keep comparatively stable denitration rate after repeatedly carrying out pulse cleaning to filter element, use after a period of time by lower for filter element mounting or dismounting observe find catalytic active substance and porous matrix 100 adhesion condition good.