Comparison of catalytic activity of alumina and silica gel for decomposition of volatile organic compounds in a plasmacatalytic reactor

Abstract

Summary form only given. Toxic volatile organic compounds (VOCs) from industrial emissions are removed by several methods including adsorption and catalytic decomposition. However, these methods are less effective and inefficient when dealing with very dilute VOCs. Electrical discharge (plasma) reactors are being developed for decomposing dilute VOCs, because in these reactors, electrical energy is selectively channeled to energize free electrons, which, in turn, initiate the desired chemical reactions in the plasma. Our recent research has proven that some suitable materials, such as alumina and silica gel, can favorably alter the plasma properties of the reactor for the decomposition of VOCs. These plasmacatalytic materials also adsorb and retain the pollutants in the reactor until they are decomposed completely to environmentally benign products, such as H/sub 2/O and CO/sub 2/. In the present study, comparisons are made among the catalytic activities of glass beads, alpha-alumina, gamma-alumina, and silica gel for the decomposition of toluene and methane in air in a pulsed corona discharge reactor. It has been found that these materials significantly enhance the decomposition efficiency of the pollutants and improve the energy efficiency of the system. Further, these materials were found to affect the concentration of plasma by-products, such as ozone, to a different extent. This characteristic provides an additional parameter to control the by-products in the air cleaning system.