Selective Catalytic Reduction Filter (SCRF)
Functions& Applications
SCRF is to coat SCR catalyst into the wall-flow particulate filter and realize the dual catalytic function of SCR and DPF to reduce NOx and PM/PN emissions. It is primarily applicable to National VI emission standard and above for road diesel engines.
Performance Characteristics
- The system is small in size, light in weight, flexible and convenient in design and installation;
- The compact structure improves the performance of cold start of SCR catalyst and exhibits excellent capture capability of PM/PN.
Lean-burn NOx Trap Catalyst (LNT)
Functions& Uses
- Lean-burn NOx Trap Catalyst Technology (LNT) is a kind of NOxpost-emission treatment technology which makes use of the change of enginemixture concentration to perform periodic adsorption-catalytic reduction of NOx,for the purpose of effectively reducing NOx emissions;
- It is principally applicable to gasoline/diesel vehicles with lean-burntechnology, which complies with National VI emission standard and above.
Performance Characteristics
The system is simple and it takes up less space.
Ammoxidation Catalyst (ASC)
Functions& Uses
- The primary function is to transform NH3 into N2 by rapid oxidation under low temperature conditions；
- It is typically applied and coated at the rear end of the SCR catalyst to prevent leakage of ammonia and to satisfy the emission standards for road diesel engines of National VI and non-road of National IV and above.
Performance Characteristics
- Good oxidation under low temperature, and the quantity of leakage of ammonia fully meets the requirements of emission standards;
- Excellent selectivity of N2 and no secondary pollutants;
- Low content of precious metals and cost-effective of product.
Catalyst for Diesel Particulate Filter (CDPF)
Functions& Uses
Catalized diesel particulate filter is mainly made of cordierite or silicon carbide materials. It employs wall-flow structure to effectively capture particulate matter in diesel engine exhaust, so as to reduce PM/PN emissions, which meets National V and National VI emission standards for road diesel engines and National IV emission standards and above for non-road diesel engines.
Passive regeneration of cDPF is assisted by catalytic oxidation of NO to NO2 through catalyst coating, and the forced controllable active regeneration can be carried out under condition of temperature supply such as fuel injection combustion/burners.
Performance Characteristics
- PM capturing efficiency achieves at least 90%, while PN capturing efficiency achieves over 95%;
- Passive regeneration temperature is low, with the equilibrium point temperature under 320°C;
- Catalyst coating features uniform distribution, high stability, low back pressure and superior consistency;
- Cordierite cDPF exhibits excellent mass and heat transfer with low cost;
- Silicon carbide cDPF exhibits high carbon loading and high temperature resistance.
Selective Catalytic Reduction (SCR) Catalyst
Functions& Uses
SCR catalyst is primarily utilized for the purification of NOx from diesel exhaust gas via ammonia selective catalytic reduction technology. The catalytic reaction equations are as follows:
There are two main categories of SCR catalysts for commercial diesel engines, V-SCR catalyst and molecular sieve SCR catalyst. The V-SCR catalysts can comply with diesel road National IV and National V emission standards. The molecular sieve SCR catalyst is further sub-divided into Cu-SCR and Fe-SCR, which are mainly applied to road diesel National VI and non-road diesel National IV emission standards and above;
SCR catalysts are also applied for treatment of NOx from vessels and stationary sources.
Performance Characteristics
- V-SCR catalysts have superior sulfur resistant performance and good conversion efficiency at temperature range of 250°C to 450°C;
- Cu-SCR catalyst exhibits excellent activity of low temperature and high stability of temperature hydrothermal;
- Fe-SCR catalyst is characterized by outstanding activity of medium and high temperature.
V-SCR
Cu-SCR
Fe-SCR
Diesel Oxidation Catalyst (DOC)
Functions& Uses
- Purification of HC, CO and soluble organic matter (SOF) in diesel exhaust by direct oxidation;
- In case of pairing DOC with SCR catalyst, NO in diesel exhaust gas can be oxidized to NO2 by upstream DOC, leading to rapid reaction of downstream SCR catalyst;
- When DOC is matched with cDPF catalyst, DOC can oxidize NO to NO2 in diesel exhaust gas, and NO2 oxidizes carbon particles to realize passive regeneration of CDPF. DOC can also oxidize injected fuel HC directly to increase the inlet temperature of CDPF catalyst, and burn carbon particles to realize active regeneration of CDPF
- It meets the National V and National VI emission standards for road diesel engines and the National IV emission standard and above for non-road diesel engines.
Performance Characteristics
- It delivers low ignition temperature for HC, CO and SOF, providing a purification efficiency of over 90%;
- It offers strong NO oxidation at low temperature, which can significantly improve NOx conversion rate at low temperature for SCR;
- It possesses a wide window of NO oxidationh, with continuous passive regeneration of cDPF, which lowers the frequency of active regeneration of cDPF and actual vehicle fuel consumption;
- It exhibits favorable resistance to high-temperature hydrothermal aging and to sulfur, offering a long service life of the product.
