Research

VALUE ANALYSIS OF COMPLEX (MULTISTEP) CHEMICAL REACTIONS

New theoretical approach of numerical analysis of chemical reactions kinetic modelsFunctions

•  Simulation of complex (multistep) chemical reactions• Analysis of kinetic models of complex chemical reactions• Creation of “basic” reaction mechanism with high prognostic capacity providing successful and optimal reaction management

Major characteristics of value theoretical approach

•  Together with mathematical simulation performs analysis of chemical reactions kinetic models aimed to quantitative revealing with time the kinetic importance of individual steps and species• Distinguishes by clearness and physical-chemical interpretability of key notions • Key notions are the values of individual steps and species characterizing their kinetic importance in reaction mechanism. Values of individual step and specie are determined as a response of reaction output parameter (rate, selectivity, induction period, change rate of reaction species concentration, etc.) on small perturbations of step rates and specie accumulation, correspondingly • Physical-chemical interpretability and calculation of kinetic trajectories of value magnitudes are based on the Hamiltonian systematization of chemical reaction systems

Major solvable tasks

•  Ranking of individual steps and species of reaction mechanism corresponding to their kinetic importance• Reduction of redundant kinetic models of multistep chemical reactions• Revealing and analysis of the reaction critical conditions by their kinetic models Numerical determination and analysis of ignition limits of branched-chain reactions• Determination of molecular structure of efficient optimal promoter/catalyst or inhibitor according to the reaction kinetic model• Revealing of prognostic capacity of reaction kinetic model • Experiment planning directed on improvement and increase of prognostic capacity of kinetic model of complex chemical reaction

Illustrating Examples

•  Ozone kinetics by Chapman mechanism• Gas-phase oxidation of formaldehyde• Hydrogen oxidation reaction• Liquid-phase oxidation of benzaldehyde and a-methyl acrolein • Liquid-phase oxidation of ethyl benzene inhibited by phenols• Non-linear dynamics in reaction system peroxidase-oxidase

Ozone kinetics

Changes in time of the value contributions (hj) of the reaction steps for atmospheric ozone transformations by Chapman mechanism

Method application

•  The essence of the theoretical method is presented in monograph of L.A. Tavadyan and G.A. Martoyan “Analysis of Kinetic Models of ChemicalReaction Systems. Value Approach”. Publ. House NAS Armenia, Yerevan 2004. • Package of kinetic computing software VALKIN is designed and approved ob the base of value analysis of reactions kinetic models. • Fundamentals and illustrating examples of kinetic models analysis by value method are used in course of lectures and practical training in the speciality “Application of computers in chemical kinetics”.

Authors

1.  Levon A. Tavadyan Institute of Chemical Physics Nac. Ac. Sci. of ArmeniaDr. Gagik A. MartoyanEcoAtom Sci.- Ind.LLC