Premium Selective Catalytic Reduction (SCR) System/Advanced Emissions Control

Product Description:

Name：SCR Selective Catalytic Reduction

Applicable vehicle type: Applicable to Euro 5/6 emission diesel vehicles

Product features: Remove the nitrogen oxygen

Product material: Copper modified molecular sieve scr

Contact information:

name: ksrcat-Davin ye

Whatsapp: +86 13335696939

Email: KSRCAT@proton.me

Attention:

1. Remove Special coating for nitrogen and oxygen

2. Thermal insulation cotton/insulation material, we have 3mm,5mm,7mm,10mm, no requirement at the time of payment (default delivery is 5mm)

3. Bulk purchase, can apply for discount, please contact us

4. The product size exists: ±1-1.5mm error, but it does not affect the use, please rest assured

5. Package includes: 1 SCR+1 strip of insulation material

Copper modified molecular sieve scr

Copper modified molecular sieve SCR catalyst and preparation method thereof
Technical field
The invention relates to the technical field of catalyst preparation, in particular to a copper modified molecular sieve SCR catalyst applied to SCR denitrification technology and a preparation method thereof.
Background technique
Selective catalytic reduction technology (selectivecatalyticreduction, SCR) was by far the most promising application in the nitrogen oxide (NOx) out of stock of one of the technology. This SCR technology refers to the technology that selectively reduces NOx to N2 under the action of catalyst, plus reducing agent or reducing substance in exhaust gas, and avoids the non-selective oxidation reaction of reducing agent. The specific process is that NH3 (reducing agent) reduces NOx in exhaust gas to N2 under the action of a certain temperature and catalyst. Therefore, the core of SCR technology is the catalyst. Currently used catalysts are generally TiO2 as the carrier, V2O5 or V2O5-WO3, V2O5-MOO3 as the active component of vanadium catalysts, the reaction temperature is about 280℃ ~ 420℃, then the conversion rate of NOx is high, but the starting temperature of 280℃ is higher than the cold start temperature of the car is only 250℃. In the range below 280℃, the conversion rate of NOx is low, so the vanadium catalyst has the defect of relatively narrow active temperature range. This defect also produces the following deficiencies: 1. To maintain the reaction temperature at 280 ° C ~ 420 ° C, the cost of reaction equipment and other aspects will be relatively high; 2. Due to the toxic vanadium contained in the catalyst system, it is easy to fall off during long-term high-temperature use, and has great biological toxicity into the environment, and will be enriched in the biological body.
So a safe catalyst suitable for low temperatures.
Content of invention
The invention provides a copper modified molecular sieve SCR catalyst and a preparation method, which can solve the problem that the catalyst of SCR reaction catalyzes NOx reduction to N2 at low temperature, and the conversion rate of NOx can reach more than 98% in the range of 220℃ ~ 370℃.
In order to solve the above problems, the technical scheme adopted by the invention is that the copper modified molecular sieve SCR catalyst comprises the ZSM-5 zeolite molecular sieve and also contains the copper element accounting for 0.4% to 13% of the mass fraction of the ZSM-5 zeolite molecular sieve.
In the above technical scheme, the more specific technical scheme can also be that the copper element is mainly evenly dispersed in the form of Cu+ on the surface and in the pore of ZSM-5.
The preparation method of this copper modified molecular sieve SCR catalyst consists of the following steps:
A. Immerse copper nitrate solution in ZSM-5 and stir at 75℃ ~ 85℃ for 24 hours;
B, then dry at 115℃ ~ 125℃ for 3.5 ~ 4.5 hours;
C, the obtained from step B is roasted at 540℃ ~ 560℃ for 3.5 ~ 4.5 hours;
D, the result of step C is naturally cooled to room temperature.
Further: the mass of copper nitrate in the copper nitrate solution is 0.8% to 26% of the mass of ZSM-5.
Further: the catalyst obtained in step D is crushed to 20 ~ 40 mesh.
Due to the adoption of the technical scheme, the invention has the following beneficial effects compared with the prior art:
1, the molecular sieve catalyst has good adsorption performance and flexibility, in the case of different metal loads, the activity of the catalyst will change accordingly, making the activity temperature controllable. The ZSM-5 molecular sieve carrier has a strong interaction with Cu ions, and adjusts and changes the electronic properties of the active component, resulting in easier reduction of the active component. Experiments show that the conversion rate of NOx can reach more than 98% in the range of 220℃ ~ 380℃. Therefore, Cu/ZSM-5 catalyst has a strong catalytic reduction effect on low temperature SCR reaction.
2. Under the catalytic reduction action of the catalyst of the invention, the conversion rate of NOx at low temperature can be up to 14 ~ 17 times faster than that at high temperature.
3. The catalyst of the invention is relatively safe and has no biological toxicity.
Concrete implementation mode
The present invention is further described in the following embodiments:
Example 1:
The copper modified molecular sieve SCR catalyst takes ZSM-5 zeolite as the carrier and is loaded with copper element accounting for 0.4% of the mass fraction of the ZSM-5 zeolite zeolite, and the copper element is mainly evenly dispersed in the form of Cu+ on the surface and in the pore channel of ZSM-5.
The preparation method is as follows:
A. Immerse A solution of 8 grams of copper nitrate in 1000 grams of ZSM-5 and stir at 75℃ for 24 hours;
B, then dry at about 120℃ for 3.5 hours;
C. Roasting the obtained from step B at a high temperature of about 550℃ for 3.5 hours;
D, the step C obtained by natural cooling to 15℃ ~ 25℃.
The prepared catalyst was pulverized to 20 ~ 40 mesh and used in SCR to catalyze NOx reduction to N2, and the conversion rate of NOx reached 89% at 220℃. At 335℃ ~ 425℃, the conversion rate of ℃NOx reaches more than 95%. In addition, the conversion rate of NOx at 220℃ is about 15 times of the average rate at 335℃ ~ 425℃.
Example 2:
The copper modified molecular sieve SCR catalyst takes ZSM-5 zeolite as the carrier and is loaded with copper element accounting for 13% of the mass fraction of the ZSM-5 zeolite zeolite, and the copper element is mainly uniformly dispersed in the form of Cu+ on the surface and in the pore channel of ZSM-5.
The preparation method is as follows:
A. Immerse 26 grams of copper nitrate solution in 100 grams of ZSM-5 and stir at 75℃ for 24 hours;
B, then dry at about 120℃ for 3.5 hours;
C. Roasting the obtained from step B at a high temperature of about 550℃ for 3.5 hours;
D, the step C obtained by natural cooling to 15℃ ~ 25℃.
The prepared catalyst was pulverized to 20 ~ 40 mesh and used in SCR to catalyze NOx reduction to N2, and the conversion rate of NOx reached 98% at 230℃ ~ 360℃.