Applications

Nitrogen oxide reduction 

SCR procedure (selective catalytic reduction)
In order to meet the increasingly stringent requirements for air pollution control, the SCR process (selective catalytic reduction), among other things, was developed for the denitrification of exhaust gases. A reducing agent (ammonia, urea or urea solution) is purposefully introduced into the hot exhaust gas stream via injection lances or nozzles, thus causing a selective NO reduction. Meanwhile, the reducing agent is sprayed in temperature ranges of 200°C to approx. 500°C. If the reducing agent has been poorly pre-distributed, one or several static mixers are set up before it enters the catalyst housing. One advantage the SCR procedure has over the SNCR procedure is that higher denitrogenation rates can be achieved with minimal NH3 escape.