Investigation of microwave enhanced catalytic degradation of VOCs with a novel double ridge field compressed cavity

Abstract

Volatile organic compounds (VOCs) are common organic pollutants that are harmful to human and the environment. Degradation of VOCs has aroused widespread concern. Catalytic oxidation is considered as an effective method to degrade VOCs. Microwave heating is a promising technology for heterogeneous catalytic gas–solid reactions, which is considered as an alternative to conventional conductive heating. Here, microwave enhanced catalytic degradation of VOCs were carried out in a novel double ridge field compressed cavity, in which Cu-Mn/AC catalyst was applied. The relative permittivity of Cu-Mn/AC at different temperatures were obtained by neural network. Further, based on the relative permittivity obtained, numerical simulations for the double ridge field compressed cavity were conducted at 2.45 GHz by a coupled three-dimensional electromagnetic-thermal model using COMSOL Multiphysics software. The simulation results of electric field distribution and temperature distribution in cavity present similar trend to the experimental results. Experimentally, the degradation of ethanol, benzene and acetone were carried out in this reactor for 50 W and 70 W at 2.45 GHz with the concentration and gas flow rate of 1000 ppm and 18 L/min. At 70 W and 2.45 GHz, the degradation efficiency of ethanol, benzene and acetone reached 99%, 70% and 99%, leading higher energy efficiency than other VOCs degradation methods.