Analysis of the Steady-State Multiplicity Behavior for Polystyrene Production in the CSTR

Abstract The work proposes two different approaches where the first one is based on the tools of the system theory and the other is strongly related to the principle of heat balance, in order to analyze the abnormal phenomena of the continuous styrene polymerization reactors, i. e. the multiplicity behavior in the wide range of operating conditions. More precisely, the multiplicity behavior of polystyrene production in a continuous stirred tank reactor (CSTR) is carried out by the numerical simulations through the Van Heerden diagram and the phase plane. Furthermore, the bifurcation diagrams in terms of two different inputs including jacket temperature and volumetric flow rate of initiator predict the appearance of multiplicity behavior as well as the saddle-node bifurcation points. The results, firstly, verify that the multiplicity behavior of the system appears under considered operating conditions. Secondly, the analysis of bifurcation behavior gives the theoretical prediction of multiplicity behavior once the operating conditions vary due to the soft constraints or the effect of noise and disturbance.