CN114308091B - Combined catalyst and preparation method and application thereof - Google Patents
Combined catalyst and preparation method and application thereof Download PDFInfo
- Publication number
- CN114308091B CN114308091B CN202111513698.3A CN202111513698A CN114308091B CN 114308091 B CN114308091 B CN 114308091B CN 202111513698 A CN202111513698 A CN 202111513698A CN 114308091 B CN114308091 B CN 114308091B
- Authority
- CN
- China
- Prior art keywords
- catalyst
- active component
- carrier
- oxide
- soot
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
Abstract
The invention discloses a combined catalyst, a preparation method and application thereof, wherein the combined catalyst is used for catalytic degradation of soot and dioxin, and comprises an outer layer catalyst and an inner layer catalyst; wherein the outer catalyst comprises a first support and a first active component comprising a transition metal oxide; the inner catalyst comprises a second carrier and a second active component, wherein the second active component comprises the first active component and NbOPO 4 Is a mixture of (a) and (b). The catalyst prepared by the invention has excellent capability of removing carbon smoke and dioxin in a synergic way, the removing efficiency of the carbon smoke is over 90 percent in the temperature range of 250-450 ℃, the removing rate of the dioxin is over 95 percent, the catalyst has excellent stability, and the catalyst is not obviously inactivated in the operation condition of 100 hours under the actual stewing Sang Lu smoke condition.
Description
Technical Field
The invention relates to the technical field of gaseous pollutant treatment, in particular to a combined catalyst, a preparation method thereof and application of the combined catalyst in garbage treatment and stewing mulberry.
Background
The roasted mulberry is mist amiable smoke generated by burning pine and cypress branches, is a special ceremony of the world gods of Tibetan worlds, is also one of daily religious lives indispensable to Tibetan rural villages, and takes Tibetan believers as a form of praying. The main fuel burned by the stewing Sang Lu is cypress branches with high oil content, and sacrificial articles such as tsamba, tea, highland barley, fruits, sugar and the like. In the process of stewing mulberry, a large amount of fine particles, namely mulberry smoke bodies, are produced in the combustion process of carbohydrates such as pine and cypress, tsamba and the like. In addition, the conifer oil content is high, and meanwhile, a certain amount of chlorine element is also present. The food such as tsamba and highland barley also contains a certain salt. The incineration mode is low-technology incineration with batch feeding and no smoke purification, and the combustion temperature range is between 250 and 850 ℃. Therefore, part of pollution components such as unburnt oil mist, organic waste gas and the like can also exist in the flue gas. The combustion condition of the stewing Sang Lu is basically incomplete combustion, the smoke exhaust height is low, fine particles (soot) and organic waste gas generated in the combustion process can bring health effects to surrounding people, and meanwhile, due to the fact that chlorine elements are brought in, the process has the potential risk of generating persistent organic environmental pollutants such as polychlorinated biphenyl and dioxin.
The catalytic degradation technology has the characteristics of simple process, short treatment flow, small occupied area and the like, is considered as an effective means for treating the carbon smoke particles, dioxin and other persistent gaseous pollutants, and is widely focused by expert scholars at home and abroad.
CN 103977792B discloses a composite oxide catalyst for catalytic combustion of soot particles in diesel exhaust, the composition of the catalyst is expressed as: ceO (CeO) 2 -MO x /La x' A 1-x' Mn y B 1-y O 3 Wherein M is one or more of Zr, pr, sm or Y, A is one or more of K, ca, ba, sr, and B is one or more of Cr, fe, co or Ni. The carbon smoke combustion catalyst has good carbon smoke catalyzing and eliminating performance, low cost, simple preparation process and easy industrial application.
CN 105148948B discloses a denitration catalyst capable of removing dioxin, which comprises the following components in percentage by mass: 0.6 to 1.8 percent of vanadium pentoxide, 6 to 8 percent of vanadium sulfate, 1 to 2 percent of tungsten trioxide, 2 to 3 percent of glass fiber, 1 to 2 percent of polyacrylic cellulose and the balance of carrier, wherein the carrier comprises titanium dioxide and carbon nano tubes, and the mass ratio of the titanium dioxide to the carbon nano tubes is 1 to 1; the invention also discloses a preparation method of the denitration catalyst capable of removing dioxin. The denitration catalyst capable of removing dioxin has the removal rate of dioxin over 80 percent, the removal rate of nitrogen oxides over 90 percent, and the catalyst has good sulfur poisoning resistance effect and meets the actual use requirement.
Therefore, the catalytic degradation technology is an effective waste gas treatment technology for treating carbon smoke particulate matters, dioxin and other persistent gaseous pollutants. However, the existing catalytic degradation process aims at a single object, and the catalyst components for treating the carbon smoke particles and dioxin in the prior art are different, so that the two processes cannot be commonly used.
Disclosure of Invention
The invention mainly aims to provide a combined catalyst and a preparation method and application thereof, so as to solve the problem of how to efficiently and stably remove carbon smoke particles and dioxin in the environment of incomplete combustion of stewing Sang Lu, medical waste, funeral waste and daily waste.
In order to achieve the above object, the present invention provides a combination catalyst for catalytic degradation of soot and dioxin, the combination catalyst comprising an outer catalyst and an inner catalyst;
wherein the outer catalyst comprises a first support and a first active component comprising a transition metal oxide; the inner catalyst comprises a second carrier and a second active component, wherein the second active component comprises the first active component and NbOPO 4 Is a mixture of (a) and (b).
In one embodiment, the first active component further comprises a promoting component, wherein the promoting component is rare earth metal oxide and/or alkaline earth metal oxide; in the outer catalyst, the mass ratio of the transition metal oxide to the auxiliary catalytic component to the first carrier is 0.01-0.05:0.01-0.05:1.
In one embodiment of the combined catalyst of the present invention, the mass ratio of the second active component to the second carrier in the inner catalyst is 0.01-0.08:1, and the first active component and NbOPO in the second active component 4 The mass ratio of (2) is 0.3:1-0.5:1.
In one embodiment of the combined catalyst of the present invention, the first support and the second support are both oxide ceramics, and the transition metal oxide is at least one of an oxide of Co, an oxide of Mn, an oxide of Cr, an oxide of Cu, and an oxide of Fe.
In one embodiment of the combined catalyst of the present invention, the outer catalyst coats the inner catalyst, the rare earth metal oxide is an oxide of La and/or an oxide of Ce, and the alkaline earth metal oxide is an oxide of Mg and/or an oxide of Ca.
In one embodiment, the first carrier is porous oxide ceramic, the thickness of the first carrier is 5-20 mm, the inner diameter of the first carrier is 30-50mm, the aperture ratio is 80-90%, and the pore density is 18-22ppi; the second carrier is microporous oxide ceramic, the thickness of the second carrier is 5-8 mm, the outer diameter of the second carrier is 30-50mm, the aperture ratio is 20-30%, and the aperture is 10-50 mu m.
In order to achieve the above object, the present invention also provides a method for preparing the above combined catalyst, comprising:
step 1, mixing a transition metal precursor with alkali liquor, adjusting the pH value to be alkaline, heating and stirring, and drying and roasting the obtained precipitate to obtain a first active component;
step 2, mixing part of the first active component with NbOPO 4 Mixing to obtain a second active component;
step 3, adding the second active component in the step 2 into the pseudo-boehmite solution and loading the pseudo-boehmite solution on a second carrier; adding the remaining first active component in the step 1 into pseudo-boehmite solution, and loading the pseudo-boehmite solution on a first carrier; roasting to obtain a combined catalyst;
wherein the first carrier encapsulates the second carrier.
In one embodiment, before the step 3 of loading, the preparation method of the combined catalyst further comprises the steps of carrying out acid soaking, alkali soaking and water washing on the first carrier and the second carrier to be neutral, and drying; the transition metal precursor is soluble salt of transition metal, a promoting component precursor is also added in the mixing process of the transition metal precursor and alkali liquor, and the promoting component precursor is soluble salt of rare earth metal and/or soluble salt of alkaline earth metal; the pH value of the step 1 is adjusted to 9-11 by adding carbonate solution.
In one embodiment, the preparation method of the combined catalyst of the invention comprises NbOPO 4 The preparation method of (2) comprises the following steps: will (NH) 4 ) 2 HPO 4 Mixing with niobium tartrate, adding surfactant, stirring, heating, drying and calcining the precipitate to obtain NbOPO 4 A material; part of the first active component and NbOPO 4 A dispersing agent is also added in the mixing process, wherein the dispersing agent is ethanol; the loading mode in the step 3 is coating.
In order to achieve the above purpose, the invention further provides the application of the combined catalyst in garbage incineration and stewing mulberry.
The technical scheme of the invention has the beneficial effects that:
(1) The catalyst has an inner layer structure and an outer layer structure, the outer layer catalyst catalyzes and removes soot, the inner layer catalyst catalyzes and removes dioxin, and the integrated removal is realized; in addition, the double-layer structure of the catalyst not only greatly improves the catalytic performance and stability of the catalyst, but also can prevent a large amount of soot from covering the surface of the inner-layer dioxin catalyst, thereby avoiding the rapid deactivation of the catalyst.
(2) In one embodiment, the inner and outer layers of the catalyst of the present invention are different carriers, and the functionality of the double-layer catalyst is enhanced. The outer porous foam oxide ceramic carrier has higher gas flow and small resistance, and is not easy to be blocked by soot deposition; the inner layer micropore oxide ceramic carrier can effectively intercept soot and inhibit toxic action of the soot on the inner layer catalytic active components.
(3) In one embodiment, the invention uses hydrotalcite-like derivative Mn-Co-La-MgO x The oxide is used as the catalyst, so that the active substances of the catalyst are uniformly distributed, and the catalyst has an excellent pore channel structure, thereby being capable of effectively improving the activity of the catalyst.
(4) The oxide composite high specific surface mesoporous niobium oxide in the catalyst disclosed by the invention can fully exert the rich acidity of the niobium oxide phosphate, improve the dechlorination capacity of the catalyst, and simultaneously can cooperate with the catalyst to strengthen the full oxidation of dechlorination products.
Drawings
Fig. 1 is a schematic view of the catalyst of the present invention for exhaust gas purification.
Detailed Description
The following describes the present invention in detail, and the present examples are implemented on the premise of the technical solution of the present invention, and detailed embodiments and processes are given, but the scope of protection of the present invention is not limited to the following examples, in which the experimental methods of specific conditions are not noted, and generally according to conventional conditions.
The invention provides a combined catalyst, which is used for catalytic degradation of soot and dioxin, and comprises an outer layer catalyst and an inner layer catalyst;
wherein the outer catalyst comprises a first support and a first active component comprising a transition metal oxide; the inner catalyst comprises a second carrier and a second active component, wherein the second active component comprises the first active component and NbOPO 4 Is a mixture of (a) and (b).
The catalyst for removing dioxin in traditional flue gas (such as roasted mulberry flue gas and garbage incineration flue gas) is mainly vanadium-based catalyst, but if a great amount of carbon smoke is mixed in the flue gas, the catalyst can be quickly deactivated, and meanwhile, the removal capability of the vanadium-based catalyst for dioxin under the coexistence condition of other volatile organic compounds is insufficient. Accordingly, the invention provides a combined catalyst which comprises an outer catalyst and an inner catalyst, wherein the outer catalyst is used for removing soot in a catalytic mode, the inner catalyst is used for removing dioxin in a catalytic mode, and the outer catalyst can prevent a large amount of soot from covering the surface of the inner dioxin catalyst so as to avoid the excessive quick deactivation of the catalyst.
In one embodiment, the catalyst of the present invention is a double-layered annular catalyst comprising an inner annular catalyst and an outer annular catalyst, the outer catalyst coating the inner catalyst.
The inner catalyst and the outer catalyst both belong to supported catalysts, the outer catalyst comprises a first carrier and a first active component, and the first active component is supported on the surface of the first carrier or in a pore canal; the inner catalyst comprises a second carrier and a second active component, wherein the second active component is loaded on the surface or in the pore canal of the second carrier.
The first active component includes a primary catalytic component, and in one embodiment, a co-catalytic component. The main catalyst component is at least one of transition metal oxides, such as the oxides of Co, mn, cr, cu, fe; in another embodiment, the main catalyst component is a mixture of Co oxide and Mn oxide, the mass ratio of the Co oxide to the Mn oxide is 3:1, and the components and the content ratio not only enable the catalyst to have better activity, but also ensure the stability of the microstructure of the catalyst.
The co-catalytic component is a rare earth metal oxide and/or an alkaline earth metal oxide, and in one embodiment, the co-catalytic component is a mixture of a rare earth metal oxide and an alkaline earth metal oxide. The rare earth metal oxide is at least one of La and Ce oxide, and the alkaline earth metal oxide is at least one of Mg and Ca oxide. In another embodiment, the promoting component is an oxide of rare earth metal La and an oxide of alkaline earth metal Mg, preferably in a mass ratio (La 2 O 3 : mgo=1:5), la enhances the utilization rate of the main catalytic active phase and the number of vacancies by strong interaction with main catalytic components such as Co and Mn, etc., and strengthens catalytic reaction activity. The alkaline earth metal Mg not only can enhance the microstructure stability of the catalyst, but also can be used as an electronic auxiliary agent to promote the oxygen mobility of the catalyst, thereby promoting the oxidation capability of the catalyst.
In one embodiment, the first support is an oxide ceramic; in another embodiment, the first support is a porous oxide ceramic, such as a porous alumina ceramic, the first support is, for example, annular in shape, the first support has a thickness of 5 to 20mm, an inner diameter of 30 to 50mm, an open porosity of 80 to 90%, and a pore density of 18 to 22ppi, such as 20ppi. The first carrier adopts a porous foam ceramic carrier, has higher gas flow and small resistance, is not easy to be blocked by soot deposition, and can improve the service life of the catalyst.
In one embodiment, the mass ratio of the main catalytic component, the co-catalytic component and the first support of the outer catalyst is from 0.01 to 0.05:0.01 to 0.05:1.
The inner catalyst comprises a second carrier and a second active component, wherein the second active component comprises the first active component and NbOPO 4 Is a mixture of (a) and (b). For example, in one embodiment, the second active component comprises a main catalyst component and NbOPO 4 In another embodiment, the second active component comprises a main catalyst component, a co-catalyst component, and NbOPO 4 Is a mixture of (a) and (b). The main catalytic component and the auxiliary catalytic component, i.e., the main catalytic component and the auxiliary catalytic component in the outer catalyst, are described in detail above and are not described herein.
In one embodiment, the second support is an oxide ceramic; in another embodiment, the second support is a microporous oxide ceramic, such as a microporous alumina ceramic, and the second support is, for example, annular and is disposed within the annular shape of the first support. The thickness of the second carrier is 5-8 mm, the outer diameter is 30-50mm, the aperture ratio is 20-30%, and the aperture diameter is 10-50 μm.
In one embodiment, the first active component and niobium oxide phosphate (NbOPO) in the second active component 4 ) The mass ratio of the second active component to the second carrier is 0.01-0.08:1 and is 0.3:1-0.5:1. In another embodiment, the content of niobium oxide phosphate in the second active component is 68wt%, so that the high specific surface area of the catalyst can be ensured under the proportioning condition, the chlorine dissociation capability for dioxin is improved, and meanwhile, the oxidation performance of the catalyst is not excessively inhibited.
The invention also provides a preparation method of the combined catalyst, which comprises the following steps:
step 1, mixing a transition metal precursor with alkali liquor, adjusting the pH value to be alkaline, heating and stirring, and drying and roasting the obtained precipitate to obtain a first active component;
step 2, mixing part of the first active component with NbOPO 4 Mixing to obtain a second active component;
step 3, adding the second active component in the step 2 into the pseudo-boehmite solution and loading the pseudo-boehmite solution on a second carrier; adding the remaining first active component in the step 1 into pseudo-boehmite solution, and loading the pseudo-boehmite solution on a first carrier; roasting to obtain a combined catalyst;
wherein the first carrier encapsulates the second carrier.
The transition metal precursor is a compound comprising a transition metal, and in one embodiment, the transition metal precursor is a soluble salt of a transition metal, i.e., a soluble salt of a transition metal that is soluble in water, such as at least one of Co, mn, cr, cu, fe.
In the present invention, the alkali solution is, for example, naOH solution. In one embodiment, the molar ratio of transition metal precursor to alkali in the alkali solution is 1:1, but the invention is not limited thereto. In another embodiment, step 1 is adjusted to a pH of 9-11 by adding a carbonate solution, such as Na 2 CO 3 The concentration of the solution and carbonate solution is, for example, 0.45mol/L, the pH value is regulated to 10+/-0.5, the precipitate is washed to be neutral by deionized water, the precipitate is dried for 12 hours at 100 ℃ after being filtered, and finally, the solid powder is calcined, ground and sieved to obtain powder with 40-60 meshes, namely the first active component.
In the invention, the second active component is based on the first active component and is additionally mixed with NbOPO 4 Obtained. Thus, step 2 of the present invention is to combine part of the first active component with NbOPO 4 Mixing to obtain the second active component. In one embodiment, the first active component and NbOPO 4 Mixing in ball milling equipment, adding ethanol as dispersant, and grinding for 2 hr under 400r/min to obtain the second active component.
Wherein, the ratio of the first active component to the second active component to be supported on the first carrier in step 1 is not particularly limited as long as the ratio of the first active component to the first carrier and the ratio of the second active component to the second carrier in the present invention can be satisfied.
In one embodiment, nbOPO 4 The preparation method of (2) comprises the following steps: will (NH) 4 ) 2 HPO 4 Mixing with niobium tartrate, adding surfactant, stirring, heating to obtain precipitateDrying and roasting the material to obtain NbOPO 4 A material. In another embodiment, (NH) 4 ) 2 HPO 4 Preparing into solution, adjusting pH to 1-3 with concentrated phosphoric acid, e.g. 2, adding niobium tartrate solution, and surfactant such as cetyltrimethylammonium bromide CTAB, heating to obtain precipitate, drying and calcining to obtain NbOPO 4 A material, wherein. (NH) 4 ) 2 HPO 4 And niobium tartrate, for example, in a molar ratio of 3-5:1.
The step 3 is as follows: adding the second active component in the step 2 into pseudo-boehmite solution, and loading the second active component on a second carrier; adding the remaining first active component in the step 1 into pseudo-boehmite solution, and loading the pseudo-boehmite solution on a first carrier; roasting to obtain the combined catalyst.
In one embodiment, the pseudo-boehmite solution has a mass concentration of 5 to 10% by weight, and the second active ingredient is added to the pseudo-boehmite solution in an amount of 10 to 15% by weight based on the mass of the pseudo-boehmite solution and is then supported on the second support, for example, by coating, more specifically, by coating the second support in a multi-pass manner, and the coating-drying process is repeated several times to achieve the desired amount of support.
In one embodiment, the amount of the first active component remaining in step 1 added to the pseudo-boehmite solution is 10 to 15% by weight based on the mass of the pseudo-boehmite solution and then supported on the first support, for example, by coating, more specifically, for example, by applying the first support in a plurality of times of pouring, and repeating the coating-drying procedure several times to achieve the desired amount of support. Finally calcining to obtain the formed catalyst.
The present invention is not particularly limited to the molding method of the first support and the second support, and the molding method of the oxide ceramic in the prior art may be any method as long as the two-layer ring specified in the present invention is formed. The present invention is not particularly limited, and the first carrier, the second carrier, and the order of loading the first active ingredient and the second active ingredient, for example, the second carrier is formed, and then the second active ingredient is loaded, and then the first carrier is formed outside the second carrier, and then the first active ingredient is loaded.
In one embodiment, the first carrier and the second carrier of the present invention are neutral by acid soaking, alkali soaking and water washing before being used for loading, and then are dried at a temperature of, for example, 100 ℃.
The catalyst is a supported inner-outer double-layer annular combined catalyst, the flue gas is firstly supported by an outer porous foam ceramic and is subjected to catalytic degradation to intercept the carbon smoke, and then the carbon smoke enters an inner microporous ceramic supported catalyst to remove the dioxin; the main component of the outer catalyst is Co-Mn-based hydrotalcite-like derivative material, and the inner catalyst component is composite niobium oxide phosphate (NbOPO) based on the outer catalyst 4 ) A material; the catalyst powder is dispersed in aluminum sol, coated on foamed ceramic and calcined at high temperature.
Fig. 1 is a schematic view of the catalyst of the present invention for exhaust gas purification. The waste gas firstly carries the catalyst through the outer porous ceramic and catalyzes and degrades the intercepted soot, then enters the inner microporous ceramic carried catalyst to remove dioxin, and the purified gas is discharged from the middle part of the inner ring of the combined catalyst.
The combined catalyst of the invention can be used for the catalytic degradation of carbon smoke and dioxin in garbage incineration and stewing mulberry, such as daily garbage, medical garbage, funeral garbage and the like, and the catalytic degradation of carbon smoke and dioxin in the process of stewing mulberry. The catalyst prepared by the invention has excellent capability of removing carbon smoke and dioxin in a synergic way, the removal efficiency of the carbon smoke is over 90 percent in a temperature range of 250-800 ℃, further in a temperature range of 250-450 ℃, the removal rate of the dioxin is over 95 percent, the catalyst has very good stability, and the catalyst is not obviously deactivated in a 100-hour operation condition under an actual stewing Sang Lu smoke condition.
The technical scheme of the invention is further described in detail by specific examples, wherein all the reagents which are not specifically described in the invention are commercially available, and the percentages which are not specifically described are mass percentages.
The preparation method of the combined catalyst in the embodiment of the invention is as follows: 1. the first carrier and the second carrier are subjected to acid soaking, alkali soaking and water washing to be neutral, and are dried at 100 ℃;
2. preparation of a first active component: respectively weighing a certain amount of nitrate of the main catalytic component and the auxiliary catalytic component, dissolving the nitrate into an aqueous solution, controlling the total concentration of metal ions to be 2mol/L (solution A), slowly adding 0.45mol/L Na into the solution A and the solution B (2 mol/L NaOH solution) in equal volumes 2 CO 3 In the solution (solution C), the pH was controlled to 10.+ -. 0.5 and the temperature was 60 ℃. And the mother liquor obtained after the reaction is completed is kept at 60 ℃ and is uniformly stirred for 9 hours. Washing the obtained precipitate with deionized water to neutrality, filtering, drying at 100deg.C for 12 hr, calcining the solid powder at 600deg.C for 4 hr, grinding, and sieving with 40-60 mesh sieve to obtain the first active component.
3. Preparing a second active component: of 2mol/L (NH) 4 ) 2 HPO 4 A solution, to which concentrated phosphoric acid is added to adjust the pH to 2. Then, an equal volume of 0.5mol/L niobium tartrate was added to the above solution with stirring, and then 5wt% (based on the mass of the above mixed solution) of cetyltrimethylammonium bromide CTAB was added. After stirring the mixture at 35℃for 1h, it was hydrothermally heated at 160℃for 24h. And (3) drying the obtained precipitate at 80 ℃ for 12 hours after filtering and washing, and finally calcining the solid powder at 500 ℃ for 4 hours, grinding and sieving the powder with 40-60 meshes to prepare the niobium oxide phosphate material. Mixing the first active component and niobium oxide phosphate in ball milling equipment according to a certain mass ratio, adding a small amount of ethanol as a dispersing agent, and grinding for 2 hours under the condition of 400r/min to obtain a second active component.
4. Forming a second carrier. Preparing 5-10wt% pseudo-boehmite solution, adding the second active component into the solution according to the solid content of 10-15wt% and stirring vigorously. The obtained colloidal solution is coated on a second carrier by a plurality of times of pouring, and is kept stand for 5 hours, dried and dried at 100 ℃ for 10 hours. The coating-drying procedure was repeated several times to achieve the desired loading.
A first carrier is formed. Preparing 5-10wt% pseudo-boehmite solution, adding the first active component into the solution with the solid content of 10-15wt% and stirring vigorously. The obtained colloidal solution is coated on a first carrier by a plurality of times of pouring, and is kept stand for 5 hours, dried and dried at 100 ℃ for 10 hours. The coating-drying procedure was repeated several times to achieve the desired loading. Finally calcining for 4 hours at 500 ℃ to obtain the formed catalyst.
Example 1:
the first carrier (outer layer carrier) is porous foam alumina ceramic (thickness 16mm, inner diameter 30mm, pore density 20ppi, aperture ratio 85%), the main catalyst component is Co-Mn-based hydrotalcite, and the auxiliary catalyst component is a mixture of rare earth metal La oxide and alkaline earth metal Mg oxide. Wherein the main catalytic component: the auxiliary catalytic component: the mass ratio of the first carrier is 0.01:0.01:1; the second carrier (inner layer carrier) is microporous alumina ceramic (thickness is 5mm, outer diameter is 30mm, average pore diameter is 10 μm, aperture ratio is 25%), the second active component is the first active component (main catalytic component+auxiliary catalytic component) and niobium oxide phosphate (NbOPO) 4 ) The mass ratio of the second active component to the second carrier was 0.01:1 in a 0.3:1 mass ratio mixture.
The catalyst with inner and outer annular functional areas has a flue gas temperature of 350 ℃ and a gas flow rate of 500m in a stewing Sang Lu 3 And/h, the removal efficiency of soot generated by combustion is 92.2%, and the removal efficiency of dioxin in the smoke is 95.3%.
Example 2:
the first carrier is porous foam alumina ceramic (thickness 16mm, inner diameter 30mm, pore density 20ppi, aperture ratio 80%), the main catalyst component is Co-Mn-Cr based hydrotalcite, and the auxiliary catalyst component is a mixture of rare earth metal La oxide, alkaline earth metal Mg oxide and Ca oxide. Wherein the main catalytic component: the auxiliary catalytic component: the mass ratio of the first carrier is 0.02:0.01:1; the second carrier is microporous alumina ceramic (thickness is 5mm, external diameter is 30mm, pore diameter is 10 μm, aperture ratio is 20%), the second active component is first active component and niobium oxide phosphate (NbOPO) 4 ) The mass ratio of the second active component to the second carrier was 0.02:1 in a 0.4:1 mass ratio mixture.
The catalyst with inner and outer annular functional areas has a gas flow rate of 500m at a temperature of 400 ℃ in a roasting Sang Lu flue gas 3 And (h) the removal efficiency of soot generated by combustion is 93.3 percent, and dioxin in the soot is removedThe removal efficiency was 97.6%.
Example 3:
the first carrier is porous foam alumina ceramic (thickness 16mm, inner diameter 30mm, pore density 20ppi, aperture ratio 90%), the main catalyst component is Co-Mn-Cu base hydrotalcite, and the auxiliary catalyst component is a mixture of rare earth metal Ce oxide, alkaline earth metal Mg oxide and Ca oxide. Wherein the main catalytic component: the auxiliary catalytic component: the mass ratio of the first carrier is 0.05:0.03:1; the second carrier is microporous alumina ceramic (thickness is 5mm, external diameter is 30mm, pore diameter is 10 μm, aperture ratio is 30%), the second active component is first active component and niobium oxide phosphate (NbOPO) 4 ) The mass ratio of the second active component to the second carrier was 0.04:1 in a 0.5:1 mass ratio mixture.
The catalyst with inner and outer annular functional areas has a gas flow rate of 800m at a temperature of 300 ℃ in a roasting Sang Lu flue gas 3 And/h, the removal efficiency of soot generated by combustion is 93.1%, and the removal efficiency of dioxin in the smoke is 96.2%.
Example 4:
the first carrier is porous foam ceramic (thickness 16mm, inner diameter 30mm, pore density 20 ppi), the main catalyst component is Co-Mn-Fe base hydrotalcite, and the auxiliary catalyst component is a mixture of rare earth metal La oxide and alkaline earth metal Mg oxide and Ca oxide. Wherein the main catalytic component: the auxiliary catalytic component: the mass ratio of the first carrier is 0.05:0.01:1; the second carrier is microporous ceramic (thickness of 5mm, outer diameter of 30mm, pore diameter of 10 μm), and the second active component is first active component and niobium oxide phosphate (NbOPO) 4 ) The mass ratio of the second active component to the second carrier was 0.08:1 in a 0.4:1 mass ratio mixture.
The catalyst with inner and outer annular functional areas has a gas flow rate of 800m at a temperature of 450 ℃ in a stewing Sang Lu flue gas 3 And/h, the removal efficiency of soot generated by combustion is 97.3%, and the removal efficiency of dioxin in the smoke is 97.7%.
Example 5:
the first carrier is porous foam ceramic (thickness 16mm, inner diameter 30mm, pore density 20 ppi), the main catalyst component is Co-Mn-Cu base hydrotalcite, and the auxiliary catalyst component isA mixture of rare earth metal La oxide and alkaline earth metal Mg oxide. Wherein the main catalytic component: the auxiliary catalytic component: the mass ratio of the first carrier is 0.05:0.05:1; the second carrier is microporous ceramic (thickness of 5mm, outer diameter of 30mm, pore diameter of 10 μm), and the second active component is first active component and niobium oxide phosphate (NbOPO) 4 ) The mass ratio of the second active component to the second carrier was 0.05:1 in a 0.5:1 mass ratio mixture.
The catalyst with inner and outer annular functional areas has a gas flow rate of 500m at a temperature of 450 ℃ in a stewing Sang Lu flue gas 3 And/h, the removal efficiency of soot generated by combustion is 97.6%, and the removal efficiency of dioxin in the smoke is 98.7%.
Example 6:
the first carrier is porous foam ceramic (thickness 16mm, inner diameter 30mm, pore density 20 ppi), the main catalyst component is Co-Mn-Fe base hydrotalcite, and the auxiliary catalyst component is a mixture of rare earth metal Ce oxide and alkaline earth metal Mg oxide and Ca oxide. Wherein the main catalytic component: the auxiliary catalytic component: the mass ratio of the first carrier is 0.03:0.03:1; the second carrier is microporous ceramic (thickness of 5mm, outer diameter of 30mm, pore diameter of 10 μm), and the second active component is first active component and niobium oxide phosphate (NbOPO) 4 ) The mass ratio of the second active component to the second carrier was 0.08:1 in a 0.2:1 mass ratio mixture.
The catalyst with inner and outer annular functional areas has a flue gas temperature of 350 ℃ and a gas flow rate of 500m in a stewing Sang Lu 3 And/h, the removal efficiency of soot generated by combustion is 93.3%, and the removal efficiency of dioxin in the smoke is 96.8%.
Example 7
The catalyst obtained in example 5 was used for incineration of medical waste at an incineration temperature of 700℃and a gas flow rate of 500m 3 And/h, the removal efficiency of soot generated by combustion is 95.6%, and the removal efficiency of dioxin in the smoke is 96.7%.
Example 8
The catalyst obtained in example 5 is used for funeral garbage incineration, the incineration temperature is 750 ℃, and the gas flow is 500m 3 And/h, the removal efficiency of soot generated by combustion is 96.0 percentThe removal efficiency of dioxin in flue gas is 97.2%.
Of course, the present invention is capable of other various embodiments and its several details are capable of modification and variation in light of the present invention by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (9)
1. The combined catalyst for the catalytic degradation of soot and dioxin is characterized by being a double-layer annular catalyst and comprising an outer-layer annular catalyst and an inner-layer annular catalyst, wherein the outer-layer catalyst coats the inner-layer catalyst;
the outer catalyst comprises a first carrier and a first active component, wherein the first active component comprises transition metal oxide, and the first carrier is porous oxide ceramic; the transition metal oxide is an oxide of Co and an oxide of Mn, or the transition metal oxide is at least one of an oxide of Co, an oxide of Mn, an oxide of Cr, an oxide of Cu, and an oxide of Fe; the inner catalyst comprises a second carrier and a second active component, wherein the second active component comprises the first active component and NbOPO 4 The second support is a microporous oxide ceramic.
2. The combination catalyst for the catalytic degradation of soot and dioxin according to claim 1, characterized in that said first active component further comprises a co-catalytic component, said co-catalytic component being a rare earth metal oxide and/or an alkaline earth metal oxide; in the outer catalyst, the mass ratio of the transition metal oxide to the auxiliary catalytic component to the first carrier is 0.01-0.05:0.01-0.05:1.
3. The combined catalyst for the catalytic degradation of soot and dioxin according to claim 2, wherein the mass ratio of the second active component to the second carrier in the inner catalyst is 0.01 to 0.08:1, the first one of the second active componentsActive ingredient and NbOPO 4 The mass ratio of (2) is 0.3:1-0.5:1.
4. The combination catalyst for catalytic degradation of soot and dioxin according to claim 2, characterized in that said rare earth metal oxide is an oxide of La and/or Ce and said alkaline earth metal oxide is an oxide of Mg and/or Ca.
5. The combination catalyst for catalytic degradation of soot and dioxin according to claim 1, characterized in that the first support has a thickness of 5 to 20mm, an inner diameter of 30 to 50mm, an open pore ratio of 80 to 90% and a pore density of 18 to 22ppi; the thickness of the second carrier is 5-8 mm, the outer diameter is 30-50mm, the aperture ratio is 20-30%, and the aperture diameter is 10-50 μm.
6. A method of preparing a combination catalyst for the catalytic degradation of soot and dioxins according to any one of claims 1 to 5, characterized by comprising:
step 1, mixing a transition metal precursor with alkali liquor, adjusting the pH value to be alkaline, heating and stirring, and drying and roasting the obtained precipitate to obtain a first active component;
step 2, mixing part of the first active component with NbOPO 4 Mixing to obtain a second active component;
step 3, adding the second active component in the step 2 into the pseudo-boehmite solution and loading the pseudo-boehmite solution on a second carrier; adding the remaining first active component in the step 1 into pseudo-boehmite solution, and loading the pseudo-boehmite solution on a first carrier; roasting to obtain a combined catalyst;
wherein the first carrier encapsulates the second carrier.
7. The method for preparing a combined catalyst for catalytic degradation of soot and dioxin according to claim 6, further comprising, before loading in step 3, subjecting the first carrier and the second carrier to acid soaking, alkali soaking, water washing to neutrality, and drying; the transition metal precursor is soluble salt of transition metal, a promoting component precursor is also added in the mixing process of the transition metal precursor and alkali liquor, and the promoting component precursor is soluble salt of rare earth metal and/or soluble salt of alkaline earth metal; the pH value of the step 1 is adjusted to 9-11 by adding carbonate solution.
8. The method for preparing a combined catalyst for catalytic degradation of soot and dioxin according to claim 6, characterized in that NbOPO 4 The preparation method of (2) comprises the following steps: will (NH) 4 ) 2 HPO 4 Mixing with niobium tartrate, adding surfactant, stirring, heating, drying and calcining the precipitate to obtain NbOPO 4 A material; part of the first active component and NbOPO 4 A dispersing agent is also added in the mixing process, wherein the dispersing agent is ethanol; the loading mode in the step 3 is coating.
9. Use of a combination catalyst for the catalytic degradation of soot and dioxin according to any one of claims 1 to 5 in waste incineration, simmering mulberry.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111513698.3A CN114308091B (en) | 2021-12-08 | 2021-12-08 | Combined catalyst and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111513698.3A CN114308091B (en) | 2021-12-08 | 2021-12-08 | Combined catalyst and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114308091A CN114308091A (en) | 2022-04-12 |
| CN114308091B true CN114308091B (en) | 2023-08-18 |
Family
ID=81051215
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111513698.3A Active CN114308091B (en) | 2021-12-08 | 2021-12-08 | Combined catalyst and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114308091B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012119299A1 (en) * | 2011-03-07 | 2012-09-13 | 山东众禾环保科技股份有限公司 | Flue gas denitration catalyst, preparation method and use thereof |
| CN106552624A (en) * | 2016-09-28 | 2017-04-05 | 天津大学 | A kind of perovskite catalyst and its laser ablation preparation method and application |
| CN108837830A (en) * | 2018-05-23 | 2018-11-20 | 江苏浩日朗环保科技有限公司 | Denitration Tuo bioxin composite catalyst and preparation method |
| CN109126773A (en) * | 2018-09-28 | 2019-01-04 | 航天凯天环保科技股份有限公司 | A kind of garbage-incineration smoke purifying catalyst and preparation method thereof |
| CN112023914A (en) * | 2020-07-23 | 2020-12-04 | 广州维港环保科技有限公司 | Dioxin removal catalyst for incineration fly ash desorption treatment and preparation method thereof |
| CN113649036A (en) * | 2021-08-27 | 2021-11-16 | 广东工业大学 | Ru-Ni/NbOPO4Bimetallic catalyst and preparation method and application thereof |
-
2021
- 2021-12-08 CN CN202111513698.3A patent/CN114308091B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012119299A1 (en) * | 2011-03-07 | 2012-09-13 | 山东众禾环保科技股份有限公司 | Flue gas denitration catalyst, preparation method and use thereof |
| CN106552624A (en) * | 2016-09-28 | 2017-04-05 | 天津大学 | A kind of perovskite catalyst and its laser ablation preparation method and application |
| CN108837830A (en) * | 2018-05-23 | 2018-11-20 | 江苏浩日朗环保科技有限公司 | Denitration Tuo bioxin composite catalyst and preparation method |
| CN109126773A (en) * | 2018-09-28 | 2019-01-04 | 航天凯天环保科技股份有限公司 | A kind of garbage-incineration smoke purifying catalyst and preparation method thereof |
| CN112023914A (en) * | 2020-07-23 | 2020-12-04 | 广州维港环保科技有限公司 | Dioxin removal catalyst for incineration fly ash desorption treatment and preparation method thereof |
| CN113649036A (en) * | 2021-08-27 | 2021-11-16 | 广东工业大学 | Ru-Ni/NbOPO4Bimetallic catalyst and preparation method and application thereof |
Non-Patent Citations (1)
| Title |
|---|
| "Highly active NbOPO4 supported Cu-Ce catalyst for NH3-SCR reaction with superior sulfur resistance";Xiaoqiang Wang et al.;《Chemical Engineering Journal》;第382卷;第122941（1-10）页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114308091A (en) | 2022-04-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108772056B (en) | Preparation of supported cordierite catalyst and photo-thermal synergetic oxidation of VOCs | |
| CN109482222B (en) | Denitration catalyst and preparation method thereof | |
| CN111569953B (en) | Preparation method of denitration catalyst | |
| CN109603807B (en) | Modified activated carbon Ce-Nb/TiO2@ AC low-temperature efficient desulfurization and denitrification catalyst and preparation method thereof | |
| CN106669673A (en) | Method for preparing CO (Carbon Monoxide) reduction denitration catalyst | |
| WO2019076090A1 (en) | Supported vocs catalytic combustion catalyst and preparation method therefor | |
| US20120302431A1 (en) | Composite catalyst and method for preparation thereof | |
| CN102489305A (en) | Transition metal composite oxide catalyst for catalytic decomposition of N2O and method for preparing catalyst | |
| CN111001415A (en) | Preparation method of composite oxide low-temperature denitration catalyst and catalyst | |
| CN111530471A (en) | Ferromanganese composite oxide based monolithic denitration catalyst and preparation method thereof | |
| CN111346678A (en) | Preparation method of denitration catalyst with aerogel as carrier and prepared catalyst | |
| CN111939896A (en) | Liquid catalyst for catalyzing ozonolysis at normal temperature and preparation method and application thereof | |
| CN111450876A (en) | Low-temperature SCR denitration catalyst using carriers with different particle sizes to load Mn and preparation method thereof | |
| CN107126949B (en) | A kind of SCR denitration and preparation method thereof of anti-arsenic poisoning | |
| CN108295865A (en) | A kind of integral honeycomb low temperature SCR denitration catalyst and preparation method thereof | |
| CN113877611B (en) | Phosphoric acid modified manganese oxide supported catalyst and preparation method thereof | |
| CN114308091B (en) | Combined catalyst and preparation method and application thereof | |
| KR20010037723A (en) | Divanadium Pentaoxide-based catalysts and their preparation method for NOx removal from flue gases | |
| CN110961114A (en) | Desulfurization and denitrification catalyst and preparation method thereof | |
| CN108671965B (en) | Semicoke low-temperature SCR denitration catalyst and preparation method thereof | |
| KR100938716B1 (en) | MANUFACTURING METHOD OF MESOPOROUS TiO2 AGGERATE SUPPORTED METAL OXIDE FOR CATALYSTIC COMBUSTION CONTAINING A PLATINUM GROUP ELEMENT | |
| JP2009219980A (en) | Catalyst for removing nitrogen oxide and its manufacturing method | |
| CN114471695A (en) | Catalyst capable of efficiently degrading cyanogen-containing waste gas and preparation method and application thereof | |
| CN111569873B (en) | Denitration catalyst | |
| CN113680383A (en) | Composite material for purifying aldehydes and benzene series in air as well as preparation method and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |