Exact steady-state multiplicity criteria for two consecutive or parallel reactions in lumped-parameter systems

Exact criteria are derived for predicting the conditions under which steady-state multiplicity occurs in lumped parameter systems in which either two consecutive or two parallel reactions occur. Most of the qualitative multiplicity features can be determined by considering four simple limiting cases in which only one reaction takes place in the system. The structure of all the possible multiplicity regions in the (Da₁, Da₂) plane is determined for both reaction networks.