Spectral dissipativity observer for a class of tubular reactors

The problem of designing a globally convergent observer for a class of tubular chemical reactors is addressed. The proposed approach combines dissipativity and modal detectability notions for distributed systems in the light of the particular tubular reactor properties due to the interplay between convective-diffusive transport and nonlinear reaction. The result is a nonlinear single-sensor observer with distributed modal measurement injection, and a global convergence condition in terms of the convection-to-diffusion Peclet number, the dominant frequency of the non-innovated dynamics, the maximum reaction rate slope, and the sensor location. The proposed design is illustrated for a representative example with non-monotonic reaction rate through simulations.