The nonlinear behaviour of the monolithic loop reactor for Fischer-Tropsch synthesis is investigated. The model consists of non-stationary mass balances in gas, liquid and solid (catalyst) phases, together with energy balance. If the external heat-exchanger is small, the system exhibits multiple steady states and the moderte-conversion state is unstable. Due to occurrence of Hopf bifurcation, only part of the high- and low-conversion states are stable. State multiplicity disappears for a large heat exchanger. However, sustained oscillations occur around desired operating points. By calculating relevant bifurcation varieties, the reactor can be designed such that the reaction ignition/ extinction and the oscillatory behaviour are avoided, even when the design parameters are uncertain or the plant is subjected to disturbances. A control structure is proposed, as an alternative solution for achieving stable operation.
- Hopf bifurcations
- monolithic reactor
ASJC Scopus subject areas
- Chemical Engineering(all)
- Computer Science Applications