The identification of kinetic models for multiphase reaction systems is complex due to the simultaneous effect of chemical reactions and mass transfers. The extentbased incremental approach simplifies the modeling task by transforming the reaction system into variant states called vessel extents, one for each rate process. This transformation is carried out from the measured numbers of moles (or concentrations) and requires as many measured species as there are rate processes. Then, each vessel extent can be modeled individually, that is, independently of the other dynamic effects. This paper presents a modified version of the extent-based incremental approach that can be used to identify multiphase reaction systems in the presence of instantaneous equilibria. Different routes are possible depending on the number and type of measured species. The approach is illustrated via the simulated example of the oxidation of benzyl alcohol by hypochlorite in a batch reactor.