ABOUT EXHAUST GASES TREATMENT
SCR (Selective Catalytic Reactor) is a catalyst aimed to the exhaust gases NOx reduction, of the metallic or ceramic substrate forming cells of triangular or square geometry, which the catalytic principle is TiO2 and V2O5 in the proportion of 10 parts of TiO2 to 1 part of V2O5.
SCR inserts in the market of NOx industrial catalyst of medium size applied to the treatment of combustion gases of internal combustion engines.
ZELDOVIC MECHANISM FORMATION OF NITROGEN OXIDES
N2 + O → NO + N
N2 + O2 → NO + O
N + OH → NO + H
When the gases temperature drops under 2000k the kinetics of the Zeldovich Mechanism suddenly reduce occurring just the formation of NO2 by the oxidation of NO, then formed.
High temperatures and concentrations of O2 result in the exponential increment of the production of nitrogen oxides of thermal origin.
THE PERFORMANCE OF A CATALYST DEPENDS ON:
- Contact area, porosity;
- Time of contact with the gases to be treated;
- Turbulence;
- Temperature;
- Chemistry.