scholarly journals Determining Robust Reaction Kinetics from Limited Data

Author(s):  
Gizem Ozbuyukkaya ◽  
Robert Parker ◽  
Goetz Veser

Accurate chemical kinetics are essential for reactor design and operation. However, despite recent advances in “big data” approaches, availability of kinetic data is often limited in industrial practice. Herein, we present a comparative proof-of-concept study for kinetic parameter estimation from limited data. Cross-validation (CV) is implemented to nonlinear least-squares (LS) fitting and evaluated against Markov chain Monte Carlo (MCMC) and genetic algorithm (GA) routines using synthetic data generated from a simple model reaction. As expected, conventional LS is fastest but least accurate in predicting true kinetics. MCMC and GA are effective for larger data sets but tend to overfit to noise for limited data. Cross-validation least-square (LS-CV) strongly outperforms these methods at much reduced computational cost, especially for significant noise. Our findings suggest that implementation of cross-validation with conventional regression provides an efficient approach to kinetic parameter estimation with high accuracy, robustness against noise, and only minimal increase in complexity.

2013 ◽  
Vol 11 (2) ◽  
pp. 641-656 ◽  
Author(s):  
Jesus Moreira ◽  
Benito Serrano-Rosales ◽  
Patricio J. Valades-Pelayo ◽  
Hugo de Lasa

Abstract This study reports the kinetic parameter estimation in the photocatalytic degradation of phenol over different TiO2 catalysts by using the Genetic Algorithm (GA) and nonlinear regression. Reaction networks are based on a previously reported unified kinetic model (UKM) of the Langmuir–Hinshelwood type. Nonlinear least-squares fitting and GA are used to find the values for the kinetic constants. The computed parameters were found to predict experimental data for phenol photodegradation at different levels of concentrations. It is shown that both methods render close values for the kinetic constants. This suggests that UKM approach gives the global minimum and as a result, this method provides good and objective parameter estimates with low to moderate cross-correlation among kinetic constants and acceptable 95% Confidence Intervals (CIs). Global optimization by using GA requires extensive computer times of up to 5 minutes. Least square fitting provides the same results with computer times of seconds only. It is then concluded that the UKM approach effectively avoids overparameterization by finding the global optimum when optimizing the kinetic constants.


1998 ◽  
Vol 45 (6) ◽  
pp. 3007-3013 ◽  
Author(s):  
B.W. Reutter ◽  
G.T. Gullberg ◽  
R.H. Huesman

Author(s):  
Ioannis K. Argyros ◽  
Santhosh George

Abstract We present a local convergence analysis of inexact Gauss-Newton-like method (IGNLM) for solving nonlinear least-squares problems in a Euclidean space setting. The convergence analysis is based on our new idea of restricted convergence domains. Using this idea, we obtain a more precise information on the location of the iterates than in earlier studies leading to smaller majorizing functions. This way, our approach has the following advantages and under the same computational cost as in earlier studies: A large radius of convergence and more precise estimates on the distances involved to obtain a desired error tolerance. That is, we have a larger choice of initial points and fewer iterations are also needed to achieve the error tolerance. Special cases and numerical examples are also presented to show these advantages.


2011 ◽  
Vol 395 (1-2) ◽  
pp. 95-106 ◽  
Author(s):  
Kyoung-Su Ha ◽  
Yun-Jo Lee ◽  
Jong Wook Bae ◽  
Ye Won Kim ◽  
Min Hee Woo ◽  
...  

1997 ◽  
Vol 62 (3) ◽  
pp. 529-534 ◽  
Author(s):  
B. A. WELT ◽  
A. A. TEIXEIRA ◽  
M. O. BALABAN ◽  
G. H. SMERAGE ◽  
D. E. HINTINLANG ◽  
...  

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