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1. Production Introduction
CAS-KR-X02 SCR de-nitrogen catalyst is of honeycomb shape taking TiO2, V2O5, WO3 as active component which is advantages in preventing of blocking, abrasion and poisoning.
SCR De-nitration catalyst is of high-tech products, mainly used in fuel electric plant, waste incineration industry, nitric acid plants, nitrate plant, steel plant, fertilizer plant and etc.
2. CAS-KR-X02 Operation condition & Technology properties
Serial No. | Test Items | Technical Specification |
Carrier specifications:150×150×50 Wall thickness= 3.7±0.1 | ||
1 | NOX concentration | ≤5000ppm |
2 | Reductive agent | Liquid ammonia, ammonia water or urea, led into as saturated gas |
3 | Space velocity | 3000~10000 h-1 |
4 | Effective operation temperature Optimal operation temperature | 150°C-420°C 260°C-300°C |
5 | NOx conversion rate | ≥90 |
6 | Service life | ≥2years |
7 | Ammonia escape ratio | ≤30ppm |
8 | Bulk density | 0.72±0.05g/mL |
9 | Crushing strength | ≥14 MPa(Front) ≥4 MPa(Side) |
10 | Coating loading | >8.0% |
11 | Active Metal oxide loading | >9.0% |
12 | Expulsion rate | <1% |
13 | Appearance | Pure black |
14 | Package | Moisture-proof and Sealed |
15 | Recommended installation Height/diameter ratio | Ceramic honeycomb 2:1;1:1 |
3. The SCR DeNOx theory & technological process
Flue gas denitration catalyst called SCR flue gas denitration catalyst,Industry terms called SCR Catalyst for short.The SCR is short for Selective Catalytive Redution.
The SCR reaction principle is that in the SCR catalyst, selectivity to NOx and NH3 reaction to produce no pollution of N2 and H2O.So SCR catalyst also called Denitration Catalyst which is the main core of flue gas from coal-fired boiler company and denitration technology, can be widely used in electric power, steel, chemical and other industries denitrification, can also be used for denitrification of nitrate, nitrate manufacturers, high temperature waste incinerator system.
SCR denitration principle is using appropriate of SCR catalyst, at a certain temperature (200--400 °C), using ammonia as the reducing agent, taking advantage of the reducing agent selective, preferentially react with nitrogen oxides, will restore it into nitrogen and water.Selective catalytic reduction efficiency is high, is able to find the best can be widely used in fixed source NOx control technology.
Inside,the reduction of NH3Nox reaction as below:
Leading reaction: 6NO+4NH3→5N2+6H2O
6NO2+8NH3→7N2+12H2O
Second reaction: 8NO+2NH3→5N2O+3H2O
8NO2+6NH3→7N2O+9H2O
4NH3+3O2→2N2+6H2O
2NH3+2O2→N2O+3H2O
The SCR method is a reliable and effective gas denitration technology, technological process of SCR method is simple, high denitration efficiency, less consumption ammonia, denitration performance is stable.At present, in the world the technology is widely used to make the Nox to reach the discharge standard which from the generating station and other enterprise.
Simple low-temperature SCR denitrification process as shown: (flue gas entered from the top of the reactor and discharged from the bottom,)
4. (The SCR DeNOx Technology Characteristics)
SCR denitrification reaction temperature is relatively low, the reduction reaction can be carried out at 200 to 400 DEG C, the reaction rate and denitrification is fast and stable, with low energy consumption.SCR denitrification efficiency can reach as high as 95%, the ammonia leak rate of less than 2 x 10-6, NOx in the exhaust gas concentration is lower than 100ppm, the normal operating temperature at 300 °C, the reaction requires a catalyst and reductant, injection point is set to a single plane, suitable for all kinds of unit.
SCR catalyst should meet the following requirements:
1.Higher NOx removal rate, low rate of escape of ammonia, purifying the exhaust NOx concentration is low;
2. In the lower temperature and wide temperature range, has high catalytic activity, namely the operation temperature window width;
3.Have good resistance to chemical stability, thermal stability, mechanical stability;4.Low operation cost.
5. The catalyst using precautions and maintenance measures
(1)Filling quantity according to the airspeed (honeycomb ceramic 10000h-1, particles 20000h-1), aspect ratio ≥ 2:1.
(2)Honeycomb ceramics type generally choose pore diameter larger than 7 mm, wall thickness greater than 0.7 mm can increase the strength and avoid clogging.
(3)The catalyst is set to 2--3, and can keep a long-term operation when the flue gas temperature is not higher than 400 °C, to avoid using when the temperature is higher than 420 °C.
(4) The sulfur content in gas mixture should be less than 5ppm, otherwise it should first desulfurization and denitration
(5)The important parameters of catalyst used for: mixed gas flow, with ammonia ratio (generally 1.1), temperature control, must through the experiments and driving tests.
(6)Flue gas flow rate and instability concentration require the using of automatic control system with ammonia than with ammonia
(7)Fresh air is preheated the catalytic bed to 200 °C before driving.
6. The application domain
SCR denitration catalyst belongs to high-tech products, mainly for the efficient denitration power plant flue gas, waste incineration of nitric acid tail gas industry and nitric acid plant, nitrate plant, steel plant, chemical fertilizer plant and other industries.
Principle: the catalyst at a certain temperature (200--400 °C), using ammonia as the reducing agent,take the advantage of the reducing agent selective, preferentially react with industrial emissions of nitrogen oxide, NOx catalytic reduction to nitrogen and water which no environmental pollution, has accelerated the catalytic role, to eliminate the purpose of NOx.