Asymptotic Observers for Heterogeneous Reaction Systems using the Concepts of Reaction and Mass-transfer Extents

For reaction systems, the state variables (the number of moles) can be expressed using the concepts of extents of reaction and mass transfer for homogeneous and heterogeneous reaction systems. In this work, a general framework for designing asymptotic observers for homogeneous and gas-liquid reaction systems is presented using the concept of the extents. For gas-liquid reaction systems, it is shown that asymptotic observers can be designed using measurements in the gas-phase. The effect of noisy measurements on the estimation of unmeasured concentrations is also discussed. The proposed asymptotic observer approach is illustrated using an example of the chlorination of butanoic acid (gas-liquid reaction system).