Rapid estimation of chemical kinetics by implicit calibration. I

In this study, methods for estimating kinetic parameters from on-line measu rements of batch reactions are developed. The basic idea is to combine non- linear parameter estimation with implicit calibration between measured spec tra and concentrations given by a known kinetic model. Several alternatives for the calibration step are discussed and the three most promising method s have been studied more closely. The basic ideas and identifiability quest ions are elucidated by simulation studies with simple kinetic models. The s imulations show that the implicit calibration method works also with uncali brated chromatograms. Two real esterification reactions with spectroscopic data are studied. In the first one, concentration data are available and ou r method gives results quite similar to those obtained in more traditional ways. The latter reaction, however, was a fast one and consequently off-lin e calibration based on known mixtures failed. In contrast, our method gave almost identical parameter values to the ones obtained by an independent st udy on the same reaction based on a complicated on-line chromatographic mea surement system. In this case the results were compared with a new way of u sing pure component spectra and generalized ridge regression with stoichiom etric constraints. Our studies show that the most important factors in obta ining reliable results are proper design of the batch experiments, proper w eighting of the initial measurements of each batch and proper measure for g oodness of fit. Copyright (C) 2001 John Wiley & Sons, Ltd.