The Resolution Of Complex Reaction Kinetics With Modified Soft Modeling Methods In The Presence Of Info-Absent Component

Soft modeling (SM) methods can be used to resolve the complicated reaction and its kinetic process whch has unknown mechanism, while SM methods also have some drawbacks, such as ambiguity of scale, misrepresentations and so on. If all the components are absorptive, using mass balance principle, the concentration profiles of all components can be resolved from the kinetic-spectral data which is online measured during the reaction process. However, when it comes to an info-absent component produced in the reaction, such as a non-absorptive intermediate in the reaction, SM methods meet a challenge in terms of how to confirm the presence or absence of the info-absent component and how to work out the concentration profiles of all components if it exists. Here some modifications of SM methods were developed to solve these problems. Mass balance error (MBE) method was used to confirm the presence or absence of the info-absent component. And evolving error analysis (EEA) method was developed to search the local mass balance region (LMBR) where the concentration of the info-absent component was low enough to be neglected. In LMBR, the concentration profiles of all absorptive components could be scaled according to least square regression. In addition, evolving time region iteration (ETRI) method was carried out to get more reliable results. At last, the concentration profiles of non-absorptive component could be resolved based on mass balance principle in the entire time region.The effectiveness of these modified SM methods has been validated by applying them to resolve the simulated data. Besides, they were applied to resolve reduction process of acidic potassium permanganate. For this reaction system, local selective range and iterative target transformation factor analysis (ITTFA) combined with multivariate curve resolution-alternating least squares (MCR-ALS) were used to get more reliable results. At last, the concentration profiles of the Mn intermediates and non-absorptive product (Mn(II)) were all resolved in the reaction between acidic potassium permanganate and different reagents, such as sodium oxaiate, hydrogen peroxide and ethanol. These scaled concentration profiles provide...