The composition, classification, and selection of denitrification catalysts?
Publishdate：2023-02-20 Views：80
Denitration catalystIt can also be divided into plate type, honeycomb type, and corrugated plate type. These three catalysts perform well in SCR denitrification, with more plate and honeycomb types and fewer corrugated plates. In the specific denitrification process, the catalyst is customized for the project, based on the composition, characteristics, efficiency, and customer requirements of the project flue gas. The characteristics of catalysts (including activity, selectivity, reliability, and regeneration) cannot be directly quantified, but rather related parameters such as activity temperature, geometric characteristic parameters, impact toughness parameters, component content, and performance indicators. In addition, the operation of all denitrification systems should also be considered, including catalyst module design, SO2/SO3 conversion rate, and catalyst lifespan. Selective denitrification catalysts also account for over 90% of commonly used denitrification catalysts in domestic and foreign thermal power plants. However, there are still many details that need to be further studied, discussed, and optimized in the specific design and application of SCR denitrification systems for generator sets, especially for new energy units such as distributed energy gas generator sets, and experience should be continuously accumulated and learned. Like other catalysts, flue gas denitrification catalysts react with NOX in the flue gas under the action of the catalyst to generate N2O and H2O, which enter the next environmental protection process with the flue gas and are discharged according to the flue gas standards. Automatically adjust the denitrification catalyst by setting up an NOX online analyzer and pressure and temperature measuring instruments. They should be stored separately from oxidants and chemicals to avoid dampness and rain. This product has no hazardous chemicals and can be used as general cargo for road, railway, and air freight.
1. Composed of denitration catalysts
At present, commercial SCR catalysts are mainly based on TiO2, with V2O5 as the basic active ingredient, WO3 as the basis, and MoO3 as an auxiliary ingredient for antioxidant and detoxification. Catalysts can be divided into three forms: plate type, honeycomb type, and corrugated plate type. The plate catalyst is based on a metal mesh rolled from stainless steel metal plates, with TiO2, V2O5, and other mixtures attached to the stainless steel mesh. By suppressing and forging, the catalytic plate is assembled into a catalyst module. Honeycomb catalysts are usually uniform catalysts. TiO2, V2O5, and a mixture of ceramic extrusion equipment and WO3 are used to make catalyst elements with a cross-section of 150mm x 150mm and different lengths, and then assembled into standard modules with a cross-section of approximately 2m1m. The processing technology of corrugated plate catalysts generally uses glass fiber enhanced TiO2 as the substrate, and active ingredients such as WO3 and V2O5 are pre immersed on the surface of the catalyst to improve catalyst activity and reduce SO2 oxidation rate.
2. Selection of denitrification catalysts
At the ash discharge level, for a certain reactor cross-section, under the same catalyst diameter, the flow area of the plate catalyst is large, generally above 85%. Secondly, the flow area of honeycomb catalysts is generally around 80%. The flow area of corrugated plate catalysts is similar to that of honeycomb catalysts. Under the same design conditions, selecting a large diameter honeycomb catalyst appropriately can achieve a drainage effect similar to that of a plate catalyst. On the three catalyst structures, the total number of corners on the plate wall is at least, the flow area is large, and it is not easy to block dust; The flow area of honeycomb catalysts is average, but the intersection angle of each catalyst wall is 90 °. In extreme smoke and dust standards, it is easy to generate ash bridging, causing catalyst blockage; The circulating cross-section of corrugated plate catalysts is average, but the wall corners are small and the total number is relatively large, making it the most prone form of dust accumulation among the three systems.
3. Catalysts can be divided into three types of plates, honeycomb and corrugated plates
The three catalysts performed well on raw coal SCR, with more plate and honeycomb types and fewer corrugated plates. The design of catalysts involves selecting a certain area of catalyst to adapt to the basic characteristics of SCR, such as flue gas flow rate, temperature, pressure, composition environment, denitrification efficiency, ammonia escape rate, etc. at the provincial coal outlet; In an environment with variable gray standards, its blockage and damage prevention characteristics are key to ensuring the long-term safe and stable operation of SCR equipment.
Denitration catalystIt can also be divided into plate type, honeycomb type, and corrugated plate type. These three catalysts perform well in SCR denitrification, with more plate and honeycomb types and fewer corrugated plates. In the specific denitrification process, the catalyst is customized for the project, based on the composition, characteristics, efficiency, and customer requirements of the project flue gas. The characteristics of catalysts (including activity, selectivity, reliability, and regeneration) cannot be directly quantified, but rather related parameters such as activity temperature, geometric characteristic parameters, impact toughness parameters, component content, and performance indicators. In addition, the operation of all denitrification systems should also be considered, including catalyst module design, SO2/SO3 conversion rate, and catalyst lifespan. Selective denitrification catalysts also account for over 90% of commonly used denitrification catalysts in domestic and foreign thermal power plants. However, there are still many details that need to be further studied, discussed, and optimized in the specific design and application of SCR denitrification systems for generator sets, especially for new energy units such as distributed energy gas generator sets, and experience should be continuously accumulated and learned. Like other catalysts, flue gas denitrification catalysts react with NOX in the flue gas under the action of the catalyst to generate N2O and H2O, which enter the next environmental protection process with the flue gas and are discharged according to the flue gas standards. Automatically adjust the denitrification catalyst by setting up an NOX online analyzer and pressure and temperature measuring instruments. They should be stored separately from oxidants and chemicals to avoid dampness and rain. This product has no hazardous chemicals and can be used as general cargo for road, railway, and air freight.
1. Composed of denitration catalysts
At present, commercial SCR catalysts are mainly based on TiO2, with V2O5 as the basic active ingredient, WO3 as the basis, and MoO3 as an auxiliary ingredient for antioxidant and detoxification. Catalysts can be divided into three forms: plate type, honeycomb type, and corrugated plate type. The plate catalyst is based on a metal mesh rolled from stainless steel metal plates, with TiO2, V2O5, and other mixtures attached to the stainless steel mesh. By suppressing and forging, the catalytic plate is assembled into a catalyst module. Honeycomb catalysts are usually uniform catalysts. TiO2, V2O5, and a mixture of ceramic extrusion equipment and WO3 are used to make catalyst elements with a cross-section of 150mm x 150mm and different lengths, and then assembled into standard modules with a cross-section of approximately 2m1m. The processing technology of corrugated plate catalysts generally uses glass fiber enhanced TiO2 as the substrate, and active ingredients such as WO3 and V2O5 are pre immersed on the surface of the catalyst to improve catalyst activity and reduce SO2 oxidation rate.
2. Selection of denitrification catalysts
At the ash discharge level, for a certain reactor cross-section, under the same catalyst diameter, the flow area of the plate catalyst is large, generally above 85%. Secondly, the flow area of honeycomb catalysts is generally around 80%. The flow area of corrugated plate catalysts is similar to that of honeycomb catalysts. Under the same design conditions, selecting a large diameter honeycomb catalyst appropriately can achieve a drainage effect similar to that of a plate catalyst. On the three catalyst structures, the total number of corners on the plate wall is at least, the flow area is large, and it is not easy to block dust; The flow area of honeycomb catalysts is average, but the intersection angle of each catalyst wall is 90 °. In extreme smoke and dust standards, it is easy to generate ash bridging, causing catalyst blockage; The circulating cross-section of corrugated plate catalysts is average, but the wall corners are small and the total number is relatively large, making it the most prone form of dust accumulation among the three systems.
3. Catalysts can be divided into three types of plates, honeycomb and corrugated plates
The three catalysts performed well on raw coal SCR, with more plate and honeycomb types and fewer corrugated plates. The design of catalysts involves selecting a certain area of catalyst to adapt to the basic characteristics of SCR, such as flue gas flow rate, temperature, pressure, composition environment, denitrification efficiency, ammonia escape rate, etc. at the provincial coal outlet; In an environment with variable gray standards, its blockage and damage prevention characteristics are key to ensuring the long-term safe and stable operation of SCR equipment.
