Nonlinear control of a selective catalytic reduction unit for a bio-fueled cogeneration plant

Abstract

The paper puts forward a method for control of selective catalytic reduction (SCR) units. First, a dynamic model of SCR performance including heat transfer, ammonia adsorption, NOx reduction, and ammonia oxidation is developed. The model is then more simplified to only include medium time scale dynamics which can be shaped using control. The obtained model is utilised in the design of a nonlinear control strategy for the regulation of the NOx emissions in the system. A robust observer of the system state is developed and exploited for control design. Numerical simulations verify the effectiveness of the proposed control system.