The non-linear behaviour of the heat-integrated multibed plug flow reactor (PFR), consisting of feed-effluent heat exchanger (FEHE), furnace, multibed adiabatic tubular reactor with intermediate cooling, and steam generator is studied. A first-order, reversible, exothermic reaction is considered. The hysteresis, isola, boundary-limit, double-zero and double-Hopf varieties are calculated. They divide parameter space into regions with different steady-state and dynamic behaviour. State multiplicity, isolated branches and oscillatory behaviour may occur for realistic values of model parameters. Implications on design are discussed.