Oxidation of Organic Compounds in Cooking Fumes by Combining Nonthermal Plasma with Mn/HZSM-5 Catalysts

Abstract

Nonthermal plasma (NTP) is an efficient treatment technology for cooking fumes (CFs). However, its practical implementation is hindered due to the low mineralization rate of CFs and high generation of by-products. In this study, a hybrid system coupling NTP and Mn/HZSM-5 catalysts was developed for the deep oxidation of CFs. These catalysts exhibited a remarkable synergistic effect together with NTP in improving the efficiency of CFs removal. When the specific energy density was 282 J·L^− 1, the hybrid system had stable reactivity, and the CFs removal efficiency and CO₂ yield were 100% and 78.4%, respectively, which were 10% and 61% higher than the values achieved with the NTP system alone. The Mn/HZSM-5 catalysts were also discovered to inhibit the production of O₃ and NO₂ to a large extent and to achieve a removal efficiency level at > 80%. The Mn/HZSM-5 catalysts’ high Mn⁴⁺/Mn ratio and the relatively large amount of chemisorbed oxygen on the catalyst surface engendered their remarkable performance. On the basis of the detected active species and organic products, the reaction mechanism governing the destruction of CFs by the NTP-Mn/HZSM-5 catalyst system was also discussed.