Feedforward ouput-feedback control for a class of exothermic tubular reactors

The problem of regulating the effluent concentration in an open-loop unstable exothermic jacketed reactor is addressed. The coolant temperature must be adjusted according to temperature as well as flow measurements. First, the robust nonlinear feedforward-output feedback stabilizing control problem is addressed with advanced control theory, yielding: (i) solvability conditions with sensor location criterion, and (ii) closed-loop robust stability coupled with simple tuning guidelines. Then, the behavior of the advanced controller is recovered with a PI temperature controller equiped with: (i) antiwindup protection, and (ii) feedforward dynamic setpoint compensation driven by measured (feed temperature and volumetric flow rate) disturbances. The approach is applied to a representative case example through numerical simulations.