Modelling chemical kinetic

E. James Davis, Microchemical Engineering The Physics and Chemistry of the Microparticle Selim M, Senkan, Detailed Chemical Kinetic Modeling Chemical Reaction Engineering of the Future... 

In algebraic equation models we also have the special situation of conditionally linear systems which arise quite often in engineering (e.g., chemical kinetic models, biological systems, etc.). In these models some of the parameters enter in a linear fashion, namely, the model is of the form,... 

Westbrook, C.K. and Dryer, F.L., Chemical kinetic modeling of hydrocarbon combustion, Prog. Energy Combust. Sci., 1984, 10, 1-57. 

The use of transition state theory as a convenient expression of rate data is obviously complex owing to the presence of the temperature-dependent partition functions. Most researchers working in the area of chemical kinetic modeling have found it necessary to adopt a uniform means of expressing the temperature variation of rate data and consequently have adopted a modified Arrhenius form... 

In addition to the linear sensitivity coefficients described above, various other types of sensitivity coefficients have been studied to probe underlying relationships between input and output parameters of chemical kinetic models. These include higher-order coefficients, Green s function coefficients, derived coefficients, feature coefficients, and principal components. Their descriptions and applications can be found in the literature [22,23, 27, 28],... 

Thermochemical data are also available from the Internet. Some examples are the NIST Chemical Kinetics Model Database (http //kinetics.nist. gov/CKMech/), the Third Millennium Ideal Gas and Condensed Phase Thermochemical Database for Combustion (A. Burcat and B. Ruscic, ftp //ftp. technion.ac.il/pub/supported/aetdd/thermodynamics/), and the Sandia National Laboratory high-temperature thermodynamic database (http //www.ca.sandia. gov/HiTempThermo/). 

The NIST Chemical Kinetics Model Database web site (http //kinetics.nist. gov/CKMech/) is a good resource for chemical kinetic models, thermochemical property data, and elementary rate coefficients. The book Gas-Phase Combustion Chemistry edited by W. C. Gardiner, Ir. (Springer-Verlag, NY, 1999) also lists many detailed mechanisms for different fuels that are available in technical papers and from the Internet. 

CHEMThermo Automatic Comparison of Thermodynamic Data for Species in Detailed Chemical Kinetic Modeling, Simmie, J. M Rolland, S. and Ryder, E. Int. J. Chem. Kinet. 37(6), 341-345, (2005). CHEMThermo analyses the differences between two thermodynamic databases in CHEMKIN format, calculates the specific heat (Cp), the enthalpy (IP), and the entropy CS °) of a species at any given temperature, and compares the values of Cp, II", S" at three different temperatures, for the species in common. Refer to the website http //www.nuigalway.ie/chem/c3/software.htm for more information. 

DETAILED CHEMICAL KINETIC MODELING CHEMICAL REACTION ENGINEERING OF THE... 

Our ability to develop detailed chemical kinetic models has improved considerably over the past decade because of simultaneous developments in a... 

Recently, a number of very efficient and transportable software packages have become available for the solution of stiff differential equations involved in detailed chemical kinetic modeling (see, for example, Hindmarsh, 1980 Petzold, 1982 Caracatsios and Steward, 1985). Consequently, the actual solution of equations no longer limits the modeling process. Instead, the limiting factor today is the availability of reliable and fundamentally based chemical reaction mechanisms. 

We must also note that detailed chemical kinetic modeling successfully is... 

An accurate knowledge of the thermochemical properties of species, i.e., AHf(To), S Tq), and c T), is essential for the development of detailed chemical kinetic models. For example, the determination of heat release and removal rates by chemical reaction and the resulting changes in temperature in the mixture requires an accurate knowledge of AH and Cp for each species. In addition, reverse rates of elementary reactions are frequently determined by the application of the principle of microscopic reversibility, i.e., through the use of equilibrium constants, Clearly, to determine the knowledge of AH[ and S for all the species appearing in the reaction mechanism would be necessary. 

Most elementary chemical reactions can be categorized as unimolecular or bimolecular events. However, further phenomenological classification is useful for the development of detailed chemical kinetic models. This way, rate parameters for new reactions can be estimated rapidly and reliably by analogy to similar reactions in the same phenomenological class. In addition, the number of different elementary reactions that must separately be treated is reduced. It must be recognized, however, that exceptional cases... 

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