Flue Gas Parameters for SCR DeNOx Catalyst Design - XINTO Catalyst | |
1、Flue Gas Amount： | Nm³/h |
2、Inlet NOx Amount： | ≤㎎/Nm³ |
3、Outlet NOx Amount： | ≤㎎/Nm³ |
4、SO2 Content： | ≤㎎/Nm³ |
5、Dust Content： | ≤㎎/Nm³ |
6、H2O Content： | ≤% |
7、Alkali Metal Content： | （Potassium, Sodium, Calcium） |
8、Denitration Effiency Request： | ≥% |
9、Design Temperature： | ℃ |
10、Using Temp. Range： | ℃ |
11、Furnace Type： | |
12、Measured Oxygen Content： | |
13、Conversion Oxygen Content： | |
14、If there is a Reactor： | Yes/No |
15、Reactor Size(If there is)： | |
16、Catalyst module layer arrangement： | |
17、Original Catalyst Parameters: | |
18、Annual Operating Conditions： | |
1> To start, especially for the first time, start ammonia injection after 30 minutes of operation;
When the SCR is just running, the catalyst itself absorbs some water, leading to a decline in activity. For the first time, it will take some time to dry it. Therefore, urea was opened half an hour late.
2> To stop the machine, stop ammonia injection 30 minutes in advance, and then press the stop button;
If the urea is stopped half an hour earlier, it will consume the excess urea and water to prevent the catalyst from getting damp.
3> The amount of ammonia injection starts from zero and increases gradually, and gradually observe to make the emission data meet the standard;
The reason why urea is adjusted from zero is that there is a deviation between the theoretical calculated value and the actual required amount, so it needs to be adjusted from zero bit by bit.
After the urea is adjusted, it can be restarted for the second time without starting from zero. Directly inject urea according to the set amount.
1. Temperature Classification and Characteristics
DeNOx catalysts currently on the market can be divided into high- temperature, middle-temperature, low-temperature and ultra-low-temperature deNOx catalysts according to the operating temperature.
The high-temperature deNOx catalyst is used at a temperature of 420-600℃, and is a copper-based, iron-based, or copper-iron-based molecular sieve catalyst coated with cordierite. It can cope with higher temperature and high concentration, has the characteristics of small size, high efficiency, and high temperature resistance. It is mainly used in various industries such as internal combustion engines and gas power generation with higher flue gas temperatures. It adopts a small modular design and a stainless steel shell, which is flexible in installation and resistant to high temperature oxidation.
Middle-temperature deNOx catalyst, is used at a temperature of 300-420℃, is a vanadium-tungsten-titanium system, which has the characteristics of high mechanical strength, wear resistance, high activity, long life, high cost performance, and has the function of demercuration. It is currently the most widely used catalyst in the market. It be used in thermal power plants.
Low-temperature deNOx catalyst, with a temperature of 180-300℃, is a vanadium molybdenum tungsten-titanium system, which has the characteristics of high and low temperature activity, sulfur and water resistance, high mechanical strength, and high activity, it is commonly used in non-power industries. At the same time, customized formula catalysts can be customized according to different industries.
Ultra-low temperature deNOx catalyst is used at a temperature of 150-180℃. It is a molybdenum-vanadium-titanium system. At ultra-low temperature, it has the characteristics of high mechanical strength, high activity, water resistance, and alkali resistance. It is often used in various furnaces and other industries. The industry of deNOx catalyst is widely used, and one catalyst can be used in many industries.
2. Classification and Characteristics of Special Industries
In order to cope with the characteristics and working conditions of flue gas in different industries, different targeted catalysts have been developed. For example, the 280℃catalyst is a catalyst that is slightly lower than the middle temperature for sintering machines and low-load boilers. It has a high cost performance of the middle temperature catalyst, and has a high deNOx activity and dioxin activity at lower temperatures. Meet the requirements of low investment and high efficiency.
According to the holes number specification of the catalyst, it is divided into 13-60 holes catalyst and other. The holes number refers to the number of catalyst channels within a distance of 150 mm on one side. The larger the number of holes, the smaller the pore diameter. The smaller the number of holes, the larger the hole diameter. Large apertures require low dust content. Conversely, small apertures require high dust content. The corresponding requirements for the number of holes and dust content are as follows:
| No. | Dust Concentration（g/Nm3） | Holes |
| 1 | 20mg | 60 |
| 2 | 50mg | 35 |
| 3 | 100mg | 30 |
| 4 | 5 | 25 |
| 5 | 15-5 | 22 |
| 6 | 15~20 | 21 |
| 7 | 20~25 | 20 |
| 8 | 25~40 | 18 |
| 9 | 40~45 | 16 |
The above data are not completely fixed and need to be adjusted according to the soot composition. For example, soot with a higher alkali metal content requires a higher number of pores to reduce the alkali metal poisoning of the catalyst.
1> Cordierite Carrier
2> Vanadium Tungsten Titanium Coated (coating amount can reach 150g)
3> High Mechanical Strength
4> 40 Cells
