TWM587563U - Ceramic fiber filter tube having low-temperature moisture-proof denitration catalyst - Google Patents

Abstract

A ceramic fiber filter tube with a low-temperature anti-water vapor denitration catalyst is suitable for removing dust and nitrogen oxides in an exhaust gas, and comprises a carrier and a plurality of catalysts attached to the carrier. The carrier is one of a filter cloth, a screen, or a filter tube. Each catalyst includes manganese and a secondary metal, and the secondary metal is selected from iron, cerium, molybdenum, copper, nickel, or a combination thereof. Based on the weight percentage of each catalyst being 100wt%, the content of manganese is 50wt% to 99wt%, and the content of the secondary metal is 1wt% to 50wt%. When the exhaust gas passes through the carrier, a dust removal and nitrogen oxidation are formed. Exhaust gas. Through the ceramic fiber filter tube with a low-temperature anti-water vapor denitration catalyst, the denitration efficiency can be maintained in a low-temperature environment containing water vapor.

Description

Ceramic fiber filter tube with low-temperature anti-water denitration catalyst

The present invention relates to a device for treating soot, in particular to a ceramic fiber filter tube with a low-temperature anti-water vapor denitration catalyst.

After the boiler in the factory undergoes combustion operations, it will generate exhaust gas with a temperature of up to 200 ° C to 1400 ° C. In order to properly use the thermal energy in the exhaust gas, the exhaust gas is often heat-recovered and the recovered thermal energy is used to generate electricity. After the heat recovery, the temperature of the exhaust gas will usually drop below 250 ° C. After the heat recovery, the catalyst must be used to remove nitrogen oxides (denitrification) and dust before discharging, so as to avoid environmental and air pollution.

At present, it has been pointed out that manganese (Mn) has better denitration activity in a low temperature environment below 250 ° C, which is a better catalyst. However, there may still be water vapor in a low temperature environment. When manganese is added, the activity of manganese will be reduced, resulting in a significant reduction in denitration efficiency. For example, in a low temperature environment of 150 ° C and 10% water vapor, the denitration efficiency is only 20%, and when the temperature is increased to 250 ° C, the denitration efficiency is only 70%.

However, the existing solution is to reheat the heat-recovered exhaust gas to more than 300 ° C, and then perform denitration to avoid the influence of water and gas on the catalyst. In addition to causing additional energy consumption, the heated exhaust gas is more May make the denitration equipment easily damaged by high temperature. Therefore, there is a need for a more effective denitration device.

Therefore, it is an object of the present invention to provide a ceramic fiber filter tube with a low-temperature anti-water vapor denitration catalyst that can maintain the denitration efficiency of exhaust gas in a low-temperature environment containing water vapor.

Therefore, the new type ceramic fiber filter tube with low-temperature anti-water vapor denitration catalyst is suitable for removing dust and nitrogen oxides in an exhaust gas, and includes a carrier and a plurality of catalysts attached to the carrier. The carrier is one of a filter cloth, a screen, or a filter tube. Each catalyst includes manganese and a secondary metal, and the secondary metal is selected from iron, cerium, molybdenum, copper, nickel, or a combination thereof. Based on the weight percentage of each catalyst being 100wt%, the content of manganese is 50wt% to 99wt%, and the content of the secondary metal is 1wt% to 50wt%. When the exhaust gas passes through the carrier, dust removal and nitrogen oxidation are formed. Exhaust gas.

The function of the new model is that through the ceramic fiber filter tube with a low-temperature anti-water vapor denitration catalyst, it is not necessary to reheat the exhaust gas after heat recovery, and the denitration of the exhaust gas can be maintained in a low temperature environment containing water vapor Efficiency, which can process the exhaust gas more efficiently, can reduce energy consumption, and avoid the carrier from being damaged by high temperature, further saving equipment costs.

Referring to FIG. 1, an embodiment of the novel ceramic fiber filter tube with a low-temperature anti-water vapor denitrification catalyst is suitable for use in a low-temperature environment below 250 ° C. and containing water vapor, and cooperates with a selective catalyst reduction technology (Selective Catalytic Reduction, SCR) for denitration, exhaust gas is removed in a dust and toxic nitrogen oxides (NO _x).

The ceramic fiber filter tube having a low-temperature anti-water vapor denitration catalyst includes a carrier 1 and a plurality of catalysts 2 attached to the carrier 1. In this embodiment, the carrier 1 is a filter tube. However, in other embodiments, the carrier 1 may also be a filter cloth or a screen, and is not limited thereto. In addition, the catalysts 2 are adhered to the carrier 1 by a wet impregnation method and then calcined.

The carrier 1 includes a plurality of interwoven ceramic fibers (not shown), which can increase the specific surface area of the carrier 1 and evenly disperse the catalysts 2 on the carrier 1 to increase the contact of the catalysts 2 to the Exhaust gas will increase the activity of these catalysts 2. The carrier 1 can filter out the dust in the exhaust gas when the exhaust gas passes. In addition to removing 80% to 99.9% of suspended particulates (Particulate Matter, PM for short), it can also remove 50% of dust. Up to 95% PM _2.5 grade dust (suspended particles with particle size less than or equal to 2.5 microns).

Referring to FIG. 1 and FIG. 2, the carrier 1 is subjected to thermogravimetric analysis (TGA), and it can be known that the carrier 1 has no thermogravimetric loss between 150 ° C. and 250 ° C., which indicates that the carrier 1 has a low temperature below 250 ° C. In the environment, water vapor is not easy to adhere to the surface of the carrier 1, so the influence of water vapor on these catalysts 2 can be reduced.

Each catalyst 2 includes manganese and a secondary metal selected from one of iron (Fe), cerium (Ce), molybdenum (Mo), copper (Cu), nickel (Ni), or a combination thereof. . It should be particularly noted that, in this embodiment, the manganese and the secondary metals used are in an oxidation state after being calcined, that is, the catalyst 2 includes manganese oxide, and the secondary metals are selected from It can be selected from iron oxide, cerium oxide, molybdenum oxide, copper oxide, and nickel oxide, or a combination thereof.

In this embodiment, based on the weight percentage of each catalyst 2 being 100 wt%, the content of manganese is 50 wt% to 80 wt%, and the content of the secondary metal is 20 wt% to 50 wt%. Among them, manganese is the main active ingredient for the denitration reaction in a low temperature environment. Therefore, the content of manganese must be more than 50% of the catalyst 2 and the content of the secondary metals must be 50% of the catalyst 2 % To maintain the activity of these catalysts 2 in a low temperature environment.

These secondary metals can increase the dispersibility of manganese, increase the chance of denitration reaction between manganese and the exhaust gas, and increase the reaction rate. These secondary metals can also change the oxidation state of manganese. In this example, since the catalytic activity and selectivity of the catalyst 2 are closely related to the oxidation state of manganese, the efficiency of the denitration reaction will follow the oxidation of manganese. The state is changed (for example, Mn ₂ O ₃ , Mn ₃ O ₄ , MnO _2, etc.). These secondary metals provide additional surface chemisorbed oxygen, which can increase the number of Brønsted acidic groups. The more Bronsted acidic groups, the stronger the activity of these catalysts 2. In addition, these secondary metals also help to provide surface acid groups such as Bronsted acid groups and Lewis acid groups, and can increase the specific surface area of manganese, which can increase the denitration reaction on the catalyst 2 Position, thereby increasing the reaction rate.

In actual operation, in the process of the exhaust gas containing dust and nitrogen oxides passing through the carrier 1, the dust therein will be filtered by the carrier 1, and the nitrogen oxides will be catalyzed by the catalysts 2 and reduced to Non-toxic nitrogen and water, the exhaust gas forms an exhaust gas that removes dust and nitrogen oxides and meets environmental protection emission standards.

In this embodiment, the catalysts 2 are processed by a wet impregnation method and subjected to calcination, so that the catalysts 2 are attached to the carrier 1 and have a moisture content of 0% to 15%, and The denitration efficiency of the carrier 1 was tested in an environment at a temperature of 150 ° C to 225 ° C. The denitration efficiency of the carrier 1 is shown in Table 1 below.

Table I
Denitrification efficiency 150 ° C to 200 ° C 200 ° C to 225 ° C Anhydrous 95% to 100% 95% to 100% 5% water vapor 95% to 100% 95% to 100% 10% water vapor 80% ～ 95% 95% to 100% 15% water vapor 70% ～ 90% 90% ～ 100%

In order to better understand the new model, the following experimental examples 1 and 2 will further explain, but the new model is not limited to the following experimental examples:

Experimental example 1

In this experimental example, a ceramic fiber filter tube is selected as the carrier 1, and the ratio of manganese and iron contained in the catalyst 2 is 2: 1. The catalysts 2 are treated by a wet impregnation method and subjected to calcination, so that the catalysts 2 are attached to the carrier 1, and the moisture content is 0% to 13%, and the temperature is 160 ° C to The denitration efficiency of the carrier 1 was tested under an environment of 190 ° C.

Referring to FIG. 3, it can be known that the ceramic fiber filter tube combined with the ferromanganese catalyst can maintain a denitration efficiency of more than 85% at various temperatures under the environment containing 10% water vapor, and the Under the environment, the denitration efficiency of more than 70% can be maintained at various temperatures. Compared with a single manganese metal catalyst, which can reach 70% of the denitration efficiency at 250 ° C, it can indeed improve the low temperature environment. Denitration efficiency. Among them, the ceramic fiber filter tube combined with ferromanganese catalyst has a denitration efficiency of more than 80% in a 175 ° C environment containing 13% water vapor.

Experimental example 2

Referring to FIG. 1 again, in this experimental example, ceramic fiber filter tubes are also used as the carrier 1, and the weight percentage of each catalyst 2 is calculated as 100% by weight. Each catalyst 2 contains 63% by weight of manganese and 32% by weight. Iron, and 5wt% molybdenum. The catalysts 2 are treated by a wet impregnation method and subjected to calcination, so that the catalysts 2 are attached to the carrier 1, and the moisture content is 0% to 13%, and the temperature is 160 ° C to The denitration efficiency of the carrier 1 was tested under an environment of 190 ° C.

Referring to FIG. 4, it can be seen that the ceramic fiber filter tube combined with the manganese iron molybdenum catalyst can maintain a denitration efficiency of more than 95% at various temperatures under an environment containing 10% water vapor, and at a temperature of 13% water vapor In the environment, the denitration efficiency of more than 88% can be maintained at various temperatures.

From the results of Experimental Example 1 and Experimental Example 2, it can be known that bimetallic catalysts or polymetallic catalysts formed by manganese with different proportions of the secondary metal, compared with single manganese metal catalysts, In the low temperature environment of water vapor, the influence of water vapor on the catalyst activity can be greatly reduced, the denitration efficiency can be improved, and the operating temperature of the denitration reaction can be expanded, which has the advantage of good versatility. In addition, in the process of denitration, by-products such as nitrous oxide (N ₂ O) will be produced, and the nitrous oxide produced in Experimental Example 2 is less than that in Experimental Example 1, and it has a lower greenhouse gas emission The advantages.

In summary, the new type ceramic fiber filter tube with low-temperature anti-water vapor denitration catalyst uses the catalysts 2 which can perform the denitration reaction in an environment containing water vapor at 150 ° C to 250 ° C, and cooperate with The carrier 1 made of ceramic fibers does not need to reheat the exhaust gas that has been heat-recovered, and can remove dust and nitrogen oxides from the exhaust gas with good efficiency in a low-temperature environment containing water vapor. It can reduce the consumption of energy, and can avoid the carrier 1 from being damaged by high temperature, and further save the equipment cost, so it can indeed achieve the purpose of new cost.

However, the above are only examples of the new model. When the scope of implementation of the new model cannot be limited by this, any simple equivalent changes and modifications made in accordance with the scope of the patent application of the new model and the content of the patent specification are still Within the scope of this new patent.

1‧‧‧ carrier

2‧‧‧ catalyst

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, among which:
1 is a cross-sectional view illustrating an embodiment of the novel ceramic fiber filter tube having a low-temperature anti-water vapor denitration catalyst;
FIG. 2 is a graph illustrating the results of thermogravimetric analysis performed on a carrier of this embodiment; FIG.
FIG. 3 is a bar graph illustrating the denitration efficiency of the carrier combined with the ferromanganese catalyst in an environment containing water vapor; and FIG. 4 is a bar graph illustrating the carrier containing the ferromanganese molybdenum catalyst containing Denitrification efficiency in a moisture environment.

Claims (4)

A ceramic fiber filter tube with a low-temperature anti-water vapor denitration catalyst is suitable for removing dust and nitrogen oxides from an exhaust gas, and includes:
A carrier; and a plurality of catalysts attached to the carrier, each catalyst including manganese and a secondary metal selected from the group consisting of iron, cerium, molybdenum, copper, nickel, or a combination thereof, with each catalyst The weight percentage is 100 wt%, the content of manganese is 50 wt% to 99 wt%, and the content of the secondary metal is 1 wt% to 50 wt%. When the exhaust gas passes through the carrier, an exhaust gas is formed to remove dust and nitrogen oxides. The ceramic fiber filter tube with a low-temperature anti-water vapor denitration catalyst according to claim 1, wherein each catalyst includes 50% to 80% by weight of manganese, and 20% to 50% by weight of the catalyst. Secondary metal. The ceramic fiber filter tube with a low-temperature anti-water vapor denitration catalyst according to claim 1 or 2, wherein the carrier comprises a plurality of interwoven ceramic fibers. The ceramic fiber filter tube with a low-temperature anti-water vapor denitration catalyst according to claim 3, wherein the carrier is one of a filter cloth, a filter screen, or a filter tube.