Incremental Identification of Reaction and Mass-Transfer Kinetics Using the Concept of Extents

This paper proposes a variation of the incremental approach to identify reaction and mass-transfer kinetics (rate expressions and the corresponding rate parameters) from concentration measurements for both homogeneous and gas-liquid reaction systems. This incremental approach proceeds in two steps: (i) computation of the extents of reaction and mass transfer from concentration measurements without explicit knowledge of the reaction and mass-transfer rate expressions, and (ii) estimation of the rate parameters for each rate expression individually from the computed extents using the integral method. The novelty consists in using extents that are computed from measured concentrations. For the computation of the individual extents, two cases are considered: if the concentrations of all the liquid-phase species can be measured, a linear transformation is used; otherwise, if the concentrations of only a subset of the liquid-phase species are available, an approach that uses flowrate and possibly gas-phase concentration measurements is proposed. The incremental identification approach is illustrated in simulation via two reaction systems, namely the homogeneous acetoacetylation of pyrrole and the gas-liquid chlorination of butanoic acid.