CN112569777A - Water-gas resistant denitration device and catalyst suitable for low-temperature environment - Google Patents
Water-gas resistant denitration device and catalyst suitable for low-temperature environment Download PDFInfo
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- CN112569777A CN112569777A CN201910920645.XA CN201910920645A CN112569777A CN 112569777 A CN112569777 A CN 112569777A CN 201910920645 A CN201910920645 A CN 201910920645A CN 112569777 A CN112569777 A CN 112569777A
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- 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
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/20—Metals or compounds thereof
- B01D2255/207—Transition metals
- B01D2255/2073—Manganese
Abstract
A water gas resistant denitration device suitable for low temperature environment is suitable for removing dust and nitrogen oxides in waste gas, and comprises a carrier and a plurality of catalysts attached to the carrier. The carrier is one of filter cloth, filter screen or filter tube, each catalyst comprises manganese and accessory metal, and the accessory metal is selected from iron, cerium, molybdenum, copper, nickel or the combination of the above. The content of manganese is 50 wt% to 99 wt%, and the content of the secondary metal is 1 wt% to 50 wt%, calculated by the weight percentage of each catalyst being 100 wt%, when the exhaust gas passes through the carrier, an exhaust gas from which dust and nitrogen oxides are removed is formed. The invention also provides a water-gas resistant denitration catalyst suitable for the low-temperature environment, and the water-gas resistant denitration device and the catalyst suitable for the low-temperature environment can still maintain the denitration efficiency in the low-temperature environment containing water gas.
Description
Technical Field
The invention relates to a smoke dust treatment device and a catalyst, in particular to a moisture-resistant denitration device and a catalyst suitable for a low-temperature environment.
Background
After the boiler in the factory is subjected to combustion operation, waste gas with a temperature as high as 200 ℃ to 1400 ℃ is generated, heat recovery is often performed on the waste gas in order to properly use heat energy in the waste gas, and the recovered heat energy is used for power generation. The temperature of the exhaust gas after heat recovery is usually reduced to below 250 ℃, and after heat recovery, the exhaust gas can be discharged after nitrogen oxides (denitration) and dust in the exhaust gas are removed by a catalyst, so as to avoid environmental and air pollution.
Currently, studies have pointed out that manganese (Mn) has better denitration activity in a low temperature environment below 250 ℃, and is a better catalyst, but since there is still moisture in the low temperature environment, the moisture will reduce the activity of manganese when attached to manganese, resulting in a great reduction in denitration efficiency. For example, in a low temperature environment of 150 ℃ and containing 10% of moisture, the denitration efficiency is only 20% left, and when the temperature is increased to 250 ℃, the denitration efficiency is only 70%.
However, the existing solution is to reheat the waste gas after heat recovery to more than 300 ℃, then denitrate, so as to avoid the influence of water vapor on the catalyst, besides causing extra energy consumption, the heated waste gas is more likely to cause the denitration equipment to be easily damaged due to high temperature. Therefore, a more efficient denitration apparatus is required.
Disclosure of Invention
The invention aims to provide a moisture-resistant denitration device which can maintain the denitration efficiency of exhaust gas in a low-temperature environment containing moisture and is suitable for the low-temperature environment.
The invention relates to a water-gas resistant denitration device suitable for a low-temperature environment, which is suitable for removing dust and nitrogen oxides in waste gas and comprises a carrier and a plurality of catalysts attached to the carrier. The carrier is one of filter cloth, filter screen or filter tube, each catalyst comprises manganese and accessory metal, and the accessory metal is selected from iron, cerium, molybdenum, copper, nickel or the combination of the above. The content of manganese is 50 wt% to 99 wt%, and the content of the secondary metal is 1 wt% to 50 wt%, calculated by the weight percentage of each catalyst being 100 wt%, when the exhaust gas passes through the carrier, an exhaust gas from which dust and nitrogen oxides are removed is formed.
The object of the present invention and the technical problems solved thereby can be further achieved by the following technical measures.
Preferably, the above-mentioned water gas resistant denitration apparatus suitable for low temperature environment, wherein each catalyst comprises 50 wt% to 80 wt% of manganese and 20 wt% to 50 wt% of the secondary metal by weight percentage.
Preferably, the above-mentioned water gas resistant denitration apparatus suitable for low temperature environment, wherein the carrier comprises a plurality of ceramic fibers interwoven with each other.
Preferably, the anti-moisture denitration device suitable for low-temperature environment, wherein the carrier is one of a filter cloth, a filter screen or a filter tube.
The invention relates to a water-gas-resistant denitration catalyst suitable for a low-temperature environment, which comprises manganese and accessory metal. The auxiliary metal is selected from iron, cerium, molybdenum, copper, nickel or the combination of the iron, the cerium, the molybdenum, the copper and the nickel, the content of manganese is 50 wt% to 99 wt%, and the content of the auxiliary metal is 1 wt% to 50 wt%, calculated by the weight percentage of the anti-moisture denitration catalyst suitable for the low-temperature environment being 100 wt%.
The object of the present invention and the technical problems solved thereby can be further achieved by the following technical measures.
Preferably, the anti-moisture denitration catalyst suitable for low-temperature environment comprises, by weight, 50 wt% to 80 wt% of manganese and 20 wt% to 50 wt% of the secondary metal.
The invention has the beneficial effects that: through the anti-moisture denitration device and the catalyst suitable for the low-temperature environment, the waste gas subjected to heat recovery does not need to be heated again, the denitration efficiency of the waste gas can be still maintained in the low-temperature environment containing moisture, the waste gas can be more efficiently treated, the energy consumption can be reduced, the carrier is prevented from being damaged by high temperature, and the equipment cost is further saved.
Drawings
FIG. 1 is a cross-sectional view illustrating an embodiment of the water and gas resistant denitration apparatus for low temperature environment according to the present invention;
FIG. 2 is a graph illustrating the results of thermogravimetric analysis of a support according to this embodiment;
FIG. 3 is a schematic diagram illustrating the denitration efficiency of the support in combination with ferromanganese catalyst in a moisture-containing environment; and
FIG. 4 is a schematic diagram illustrating the denitration efficiency of the support in combination with a ferromanganese molybdenum catalyst in a moisture-containing environment.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings and examples.
Referring to fig. 1, an embodiment of the moisture-resistant and denitration apparatus for low temperature environment of the present invention is suitable for low temperature environment with temperature below 250 ℃ and moisture, and is used in conjunction with Selective Catalytic Reduction (SCR) to perform denitration, so as to remove dust and toxic Nitrogen Oxides (NO) in exhaust gasx)。
The anti-moisture denitration device suitable for low temperature environment comprises a carrier 1 and a plurality of catalysts 2 attached to the carrier 1. In the embodiment, the carrier 1 is a filter tube, but in other embodiments, the carrier 1 may be a filter cloth or a filter screen, and the like, which is not limited thereto. The catalyst 2 is treated by a wet impregnation method and is calcined to be attached to the carrier 1.
The carrier 1 includes a plurality of ceramic fibers (not shown) interlaced with each other, which can increase the specific surface area of the carrier 1, and make the catalyst 2 uniformly dispersed on the carrier 1, thereby increasing the chance of the catalyst 2 contacting the exhaust gas, and increasing the activity of the catalyst 2. The carrier 1 can filter dust in the exhaust gas when the exhaust gas passes through, and can remove 50% to 95% of PM2.5 grade dust (suspended particles with the particle size less than or equal to 2.5 microns) in addition to 80% to 99.9% of suspended particles (referred to as PM for short).
Referring to fig. 1 and 2, Thermogravimetric analysis (TGA) of the carrier 1 shows that the carrier 1 has no thermal weight loss between 150 ℃ and 250 ℃, which means that even in a low temperature environment below 250 ℃, moisture is not easily attached to the surface of the carrier 1, and therefore the influence of moisture on the catalyst 2 can be reduced.
Each catalyst 2 includes manganese and a secondary metal selected from one or a combination of iron (Fe), cerium (Ce), molybdenum (Mo), copper (Cu), and nickel (Ni). It should be noted that, in this embodiment, the manganese and the secondary metal are both in oxidation state after calcination, that is, the catalyst 2 includes manganese oxide, and the secondary metal is one or the combination of iron oxide, cerium oxide, molybdenum oxide, copper oxide and nickel oxide.
In this embodiment, the manganese content is 50 wt% to 80 wt%, and the secondary metal content is 20 wt% to 50 wt%, calculated as 100 wt% of each catalyst 2. Manganese is a main active component for denitration reaction in a low temperature environment, and therefore, the content of manganese should be 50% or more of the catalyst 2, and the content of the secondary metal should be 50% or less of the catalyst 2, so as to maintain the activity of the catalyst 2 in a low temperature environment.
The secondary metal can increase the dispersibility of manganese, so as to increase the opportunity of carrying out denitration reaction on manganese and the waste gas and improve the reaction rate. The secondary metal also changes the oxidation state of manganese, and since in this example the catalytic activity and selectivity of catalyst 2 is closely related to the oxidation state of manganese, the efficiency of the denitration reaction will vary with the oxidation state of manganese (e.g., Mn)2O3、Mn3O4、MnO2Etc.) to change. The secondary metal provides additional surface chemical adsorption of oxygen, which can improve the Bronst
The more the number of acid groups, the more bronsted acid groups, the stronger the activity of the catalyst 2. In addition, the secondary metal contributes to providing surface acid groups such as bronsted acid groups and Lewis acid groups, and can increase the specific surface area of manganese, increase the sites on the catalyst 2 where denitration can be performed, and thus increase the reaction rate.
In practical operation, in the process that the waste gas containing dust and nitrogen oxides passes through the carrier 1, the dust in the waste gas is filtered by the carrier 1, and the nitrogen oxides are catalyzed by the catalyst 2 and reduced into nontoxic nitrogen and water, so that the waste gas forms a discharge gas which is free of dust and nitrogen oxides and meets the environmental emission standard.
In this embodiment, the catalyst 2 is treated by wet impregnation and calcined to adhere the catalyst 2 to the carrier 1, and the denitration efficiency of the carrier 1 is tested in an environment with a moisture content of 0% to 15% and a temperature of 150 ℃ to 225 ℃, and is shown in the following table.
Watch 1
For a better understanding of the invention, the following examples 1 and 2 are given by way of illustration, but the invention is not limited to the following examples:
experimental example 1
In this experimental example, a ceramic fiber filter tube is selected as the carrier 1, and the ratio of manganese to iron contained in the catalyst 2 is 2: 1. the catalyst 2 is treated by a wet impregnation method and calcined, so that the catalyst 2 is attached to the carrier 1, and the denitration efficiency of the carrier 1 is tested in an environment with a moisture content of 0% to 13% and a temperature of 160 ℃ to 190 ℃.
Referring to fig. 3, it can be seen that the ceramic fiber filter tube combined with the ferromanganese catalyst can maintain a denitration efficiency of 85% or more at each temperature in an environment containing 10% of water vapor, and can maintain a denitration efficiency of 70% or more at each temperature in an environment containing 13% of water vapor, and the denitration efficiency in a low temperature environment can be improved compared to the denitration efficiency of 70% achieved by a single manganese metal catalyst at 250 ℃. The ceramic fiber filter tube combined with the ferromanganese catalyst has the denitration efficiency of more than 80 percent under the environment of 175 ℃ containing 13 percent of water vapor.
Experimental example 2
Referring back to fig. 1, in the present experimental example, a ceramic fiber filter tube was also used as the carrier 1, and each catalyst 2 contained 63 wt% of manganese, 32 wt% of iron, and 5 wt% of molybdenum, based on 100 wt% of each catalyst 2. The catalyst 2 is treated by a wet impregnation method and calcined, so that the catalyst 2 is attached to the carrier 1, and the denitration efficiency of the carrier 1 is tested in an environment with a moisture content of 0% to 13% and a temperature of 160 ℃ to 190 ℃.
Referring to fig. 4, it can be seen that the ceramic fiber filter tube combined with the ferromanganese molybdenum catalyst can maintain the denitration efficiency of 95% or more at each temperature in an environment containing 10% moisture, and can maintain the denitration efficiency of 88% or more at each temperature in an environment containing 13% moisture.
From the results of experimental examples 1 and 2, it can be seen that the bi-metal catalyst or multi-metal catalyst formed by mixing manganese with the secondary metal in different proportions can greatly reduce the influence of moisture on the catalyst activity in a low temperature environment containing moisture, improve the denitration efficiency, and enlarge the operating temperature of the denitration reaction, compared with the single manganese metal catalyst, and has the advantage of good versatility. In addition, nitrous oxide (N) is generated during the denitration process2O), etc., and the nitrous oxide generated in experimental example 2 is less than that generated in experimental example 1, and has an advantage of reducing greenhouse gas emission.
Claims (6)
1. The utility model provides a prevent water gas denitration device suitable for low temperature environment, is applicable to and gets rid of dust and nitrogen oxide in the waste gas, its characterized in that: the anti-moisture denitration device suitable for the low temperature environment comprises:
a carrier; and
and a plurality of catalysts attached to the carrier, each catalyst comprising manganese and a secondary metal selected from iron, cerium, molybdenum, copper, nickel or a combination thereof, wherein the content of manganese is 50 wt% to 99 wt% and the content of the secondary metal is 1 wt% to 50 wt% based on 100 wt% of each catalyst, and when the exhaust gas passes through the carrier, an exhaust gas from which dust and nitrogen oxides are removed is formed.
2. The water and gas resistant denitration device suitable for low temperature environment of claim 1, wherein: each catalyst comprises 50 wt% to 80 wt% of manganese and 20 wt% to 50 wt% of the secondary metal, in weight percentage.
3. The moisture and gas resistant denitration apparatus suitable for low temperature environment according to claim 1 or 2, wherein: the carrier includes a plurality of ceramic fibers interwoven with one another.
4. The water and gas resistant denitration device suitable for low temperature environment of claim 3, wherein: the carrier is one of filter cloth, a filter screen or a filter tube.
5. The utility model provides a water gas resistant denitration catalyst suitable for low temperature environment which characterized in that: comprises the following steps:
manganese; and
and the secondary metal is selected from iron, cerium, molybdenum, copper, nickel or the combination of the iron, the cerium, the molybdenum, the copper and the nickel, the content of manganese is 50 wt% to 99 wt%, and the content of the secondary metal is 1 wt% to 50 wt%, wherein the weight percentage of the anti-moisture denitration catalyst suitable for the low-temperature environment is 100 wt%.
6. The moisture and gas resistant denitration catalyst suitable for low-temperature environment according to claim 5, wherein: the manganese-containing alloy comprises 50 wt% to 80 wt% of manganese and 20 wt% to 50 wt% of the secondary metal in percentage by weight.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN201910920645.XA CN112569777A (en) | 2019-09-27 | 2019-09-27 | Water-gas resistant denitration device and catalyst suitable for low-temperature environment |
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| CN201910920645.XA CN112569777A (en) | 2019-09-27 | 2019-09-27 | Water-gas resistant denitration device and catalyst suitable for low-temperature environment |
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| CN107398133A (en) * | 2016-05-19 | 2017-11-28 | 富利康科技股份有限公司 | Strengthening method of ceramic fiber filter tube and strengthened ceramic fiber filter tube |
| CN207169295U (en) * | 2016-12-15 | 2018-04-03 | 富利康科技股份有限公司 | Ceramic fiber filter tube capable of filtering suspended aerosol and gaseous pollutants |
| TWI641693B (en) * | 2018-02-07 | 2018-11-21 | 富利康科技股份有限公司 | Coke oven flue gas dedusting, desulfurization and denitration integrated method and equipment |
| TWM578359U (en) * | 2019-01-14 | 2019-05-21 | 富利康科技股份有限公司 | Equipment used to remove dioxin waste gas from hazardous industrial waste incineration and having ceramic fiber filter tube |
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Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
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| US2910343A (en) * | 1955-12-08 | 1959-10-27 | Du Pont | Process for catalytically reducing nitrogen oxides in industrial stack gases |
| GB1438120A (en) * | 1972-09-01 | 1976-06-03 | Exxon Research Engineering Co | Removal of nitrogen oxides from flue gas |
| CN103638942A (en) * | 2013-12-17 | 2014-03-19 | 中国建筑材料科学研究总院 | SCR (selective catalytic reduction) catalyst for denitrating low-temperature smoke of cement kiln and preparation method thereof |
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| CN107398133A (en) * | 2016-05-19 | 2017-11-28 | 富利康科技股份有限公司 | Strengthening method of ceramic fiber filter tube and strengthened ceramic fiber filter tube |
| TWI594793B (en) * | 2016-09-23 | 2017-08-11 | 國立高雄應用科技大學 | Catalytic material of ferrite for treating nox in waste gases with selective catalytic reduction reaction and method thereof |
| CN106732641A (en) * | 2016-11-14 | 2017-05-31 | 江苏省陶瓷研究所有限公司 | A kind of new ceramic-film tube with catalysis and preparation method thereof |
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| TWI641693B (en) * | 2018-02-07 | 2018-11-21 | 富利康科技股份有限公司 | Coke oven flue gas dedusting, desulfurization and denitration integrated method and equipment |
| TWM578359U (en) * | 2019-01-14 | 2019-05-21 | 富利康科技股份有限公司 | Equipment used to remove dioxin waste gas from hazardous industrial waste incineration and having ceramic fiber filter tube |
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