The kinetics of the pyrolysis of n‐hexane was studied in a conventional static reactor over a temperature range of 650–840 K. The overall reaction is essentially first order with the kinetic parameters A = 1013.92 s−1 and EA = 260.3 kJ/mol. The distributions of the main products were analyzed by gas chromatography. A reaction model involving 240 elementary reactions was developed to describe the experimental rate data. The agreement of the model with experimental data was surprisingly good over a wide range of temperatures and pressures and up to medium extents of conversion. Methods for sensitivity studies based upon the quasi‐stationary‐state assumption (QSSA) were developed, and for a number of more detailed effects, such as self‐inhibition, explanations could be given. It was also shown that the hexyl isomerization reactions influence strongly the product distribution. The outstanding capability of kinetic modeling with computer simulations in handling complex kinetic systems is demonstrated.

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Dedicated to Professor Matthias Seefelder on the occasion of his 60th birthdayModern digital methods and powerful computers make it possible to simulate the time behavior of chemical reactions. These calculations can be performed on systems containing an almost unlimited number of elementary reactions. Generally, however, the reaction models used should contain only those elementary reactions which describe the bulk of the conversion. Such a reaction model may be obtained by reduction of the complete set of elementary reactions. Another possibility is analysis of the chemical system starting from conditions ensuring a simple chemistry, which is generally the case at low temperatures and low conversions. The reaction model may then be extended into the range of the reaction variables (temperature, time) of interest. Mathematical simulations may be helpful during the development of the reaction model, and sometimes even decisive. These methods were applied to the pyrolysis of ethylbenzene and n-hexane, and to CO oxidation. They yield information on the reaction paths, the importance of particular elementary reactions, and reaction stability. Furthermore, quantitative data can be obtained concerning the influence of single elementary reactions on the product distribution. The sensitivity matrix shows, e.g., whether the determination of kinetic parameters of an elementary reaction from kinetic data of the overall reaction is possible in principle, and how high the accuracy of the rate constants should be for simulation of the reaction. Both results are important for modeling chemical reactions.

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The kinetics of the pyrolysis of n-hexane was studied in a conventional static reactor over a temperature range of 650-840 K. The overall reaction is essentially first order with the kinetic parameters A = 1013,g2 s-l and EA = 260.3 kJ/mol. The distributions of the main products were analyzed by gas chromatography. A reaction model involving 240 elementary reactions was developed to describe the experimental rate data. The agreement of the model with experimental data was surprisingly good over a wide range of temperatures and pressures and up to medium extents of conversion. Methods for sensitivity studies based upon the quasi-stationary-state assumption (QSSA) were developed, and for a number of more detailed effects, such as self-inhibition, explanations could be given. It was also shown that the hexyl isomerization reactions influence strongly the product distribution. The outstanding capability of kinetic modeling with computer simulations in handling complex kinetic systems is demonstrated.