A CONTROL SYSTEM FOR NITROGEN OXIDES POLLUTION ABATEMENT BY SCR (SELECTIVE CATALYTIC REDUCTION)

摘要

This paper deals with the control of nitrogen oxides emission in thermal power plants by the use of the so-called Selective Catalytic Reduction (SCR) technology. A model of the process based on first principles and suitable constitutive equations has been developed. The corresponding simulator points out that the effect of inlet ammonia concentration on outlet nitrogen oxides concentration is adequately described by a low order linear model in all typical operating conditions. Such a model is used to design a control system capable of maintaining the pollutant emissions under a prescribed threshold, while reducing the ammonia slip at the reactor outlet. The proposed controller is verified through several simulation tests.