In this paper, a linear-quadratic controller is formulated for a catalytic flow reversal reactor (CFRR) using an infinite-dimensional Hilbert space representation of the system. The controller is developed on the basis of the catalytic reactor model with unidirectional flow and is formulated to keep the distribution of the temperature along the axis of the reactor at stationary state by using the fluid flow velocity. To formulate the controller, a linear infinite-dimensional state space description is used. Using the infinite-dimensional state space representation, a state LQ-feedback operator is computed via the solution of a Riccati differential equation. The controller is formulated and tested numerically for the catalytic combustion of lean methane emissions. (c) 2007 Elsevier Ltd. All rights reserved.