Kinetics and mechanism of naphthalene oxidation by non-linear estimation

Abstract

The data of Ioffe and Sherman for the reaction in which naphthalene undergoes vapour-phase oxidation in the presence of vanadium oxide catalyst have been re-examined by the method of non-linear estimation. In a digital computer procedure the differential rate equations are generated from a special-purpose kinetics language and solved by numerical integration with parameter values obtained by non-linear estimation. Application is made to both constant-temperature and temperature-dependent kinetics where the order of reaction is either prescribed or estimated from the data. In the study of reaction mechanisms, the procedure is extended from the single chemical species, naphthalene, to the several chemical species found as products of reaction. Results are compared with those obtained by Ioffe and Sherman and other workers as well as by such alternative techniques as linear regression. Apart from presenting revised parameter estimates and confirming observations previously reported by Ioffe and S[spherman], it has been shown that: (1) internal pore diffusion with first-order kinetics dominates at temperatures above 350°C; (2) the mechanism proposed by D'Alessandro and Farkas in which naphthalene additionally undergoes complete oxidation is also an adequate representation of the data; and (3) discrepancies in the fit of 1, 4-naphthoquinone at temperatures above 350°C suggest the presence of a related intermediate product, 1, 2-naphthoquinone, detected by later researchers. © 1962.