Modeling intrinsic kinetics in a reactor of corona discharge coupled with TiO2-activated carbon fibre for ethylene degradation and ozone regulation

Abstract

A reactor that is able to degrade ethylene efficiently inside a cold humid storehouse was designed for the purpose of extending the shelf-life of horticultural products. The reactor generates non-thermal plasma by corona discharge, improves the ethylene degradation efficiency, and controls the ozone concentration with titanium dioxide-activated carbon fibre (TiO2/ACF). To arrive at a rational reactor design, we investigated the intrinsic kinetics of the reaction process. According to the order of reaction, reactions in which ethylene or ozone are involved in the discharge process could be classified into four categories: non-thermal plasma formation, ethylene degradation, ethylene ozonolysis, and ozone decomposition. Therefore, we present an intrinsic kinetics model, which is in the form of an autonomous first-order ordinary differential equation set, combining two dependent variables, i.e., the concentrations of ethylene and ozone. Experimental data obtained for the corona discharge, the corona discharge coupled with an ACF film, and a corona discharge coupled with a TiO2/ACF film proved that the model is capable of describing the concentrations of ethylene and ozone. The rate constants reveal that the intrinsic kinetics as internal mass transport are accounted for. The corona discharge coupled with the TiO2/ACF film increased the rate constant of ethylene degradation (k2) and decreased the rate constant of ozone formation (k1). However, it did not obviously influence the rate constant of ethylene ozonolysis (k3) and the rate constant of ozone decomposition (k4).