SELECTIVITY STUDIES IN THE PHOTOCHLORINATION OF METHANE .1. REACTOR MODEL AND KINETIC-STUDIES IN A NONISOTHERMAL, POLYCHROMATIC ENVIRONMENT

The photochlorination of methane employing nitrogen as an inert diluent is studied in a continuous flow, tubular, non-isothermal, bench-scale, polychromatically irradiated photoreactor with particular emphasis on selectivities. Using a mechanistic sequence of 22 steps, predictions from the mathematical model are compared with experimental results obtained for three different nominal temperatures (297.9 K, 312.8 K and 322.2 K) and three different radiation sources (40, 360 and 1200 W) that also differ in their output emission characteristics. An extremely high sensitivity to some of the values of the employed specific rate constants is found, particularly when an accurate prediction of selectivities is being sought. However, within the reported or attributable errors in the published values of the kinetic constants (±5%), the experiments show very good agreement with the computed predictions obtained from the mathematical model of the photoreactor. Using these experimental results that show excellent reproducibility a complete and reliable set of process independent reaction kinetic constants, and a verified reactor model are obtained which can be used for photoreactor design purposes, including selectivity optimization. © 1991, Taylor & Francis Group, LLC. All rights reserved.