A mathematical procedure for deriving overall rate equations based on the theory of complex reactions: Application to analysis of catalytic cracking of n-butane over zeolites

• Published in: Chemical engineering science Vol. 93; pp. 326 - 340
• Main Authors: Rahimi, Nazi, Karimzadeh, Ramin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-04-2013
• Subjects: Catalysts; Catalytic cracking; Chemical engineering; Complex reaction; computer software; equations; FORTRAN; Kinetics; Mathematical analysis; Mathematical modeling; Mathematical models; Methodology; Overall rate equations; Quasi-steady state; Zeolite; Zeolites; CC; QSS; RR; OR; Overall rate equations; MRI; LHHW; Quasi-steady state; Mathematical modeling; Complex reaction; Kinetics; Zeolite
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2013.01.034

In the conventional theory of complex reactions, overall reactions (ORs) are required to be determined in the first step to specify the stoichiometric matrix. In the present paper, a systematic and straightforward method is proposed for deriving reaction routes (RRs), ORs, and the basic RRs based on the theory of complex reactions. The intermediates are rearranged in a matrix herein named “the matrix of intermediates” which facilitates the combination of elementary reactions building the ORs, distinctively when the number of elementary reactions exceeds. The computer program developed in FORTRAN programming language could execute our suggested methodology automatically. A simple mathematical procedure is further introduced for obtaining explicit overall rate expressions of reactants/products molecules involved in various elementary reactions. The mechanism of n-butane catalytic cracking (CC) over HZSM-5 catalyst has been illustrated as a typical catalytic heterogeneous reaction due to its increasing significance. Both the utilization of the introduced methodology and the theory of complex reactions have been employed for the first time to investigate CC of n-butane over zeolites.
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► A systematic procedure to derive the reaction routes and the overall reactions. ► A FORTRAN computer program for predicting the basis of reaction routes. ► The quasi-steady state overall rate equation of any reactant/component in complex mechanisms. ► The overall rate of ethylene consumption in catalytic cracking of n-butane over HZSM-5.