Catalytic Oxidation of Volatile Organic Compounds Using the Core–Shell Fe2O3-Cenospheric Catalyst in a Fluidised Bed Reactor

Abstract

The results of selected volatile organic compounds (benzene, n-hexane, isopropanol, and formic acid) catalytic oxidation are presented on Fe2O3 cenospheres in the fluidised bed reactor. The core–shell Fe2O3-cenosphere catalyst was developed by applying an Fe layer on cenospheres by FB-MO-CVD (fluidised bed, metal–organic chemical vapor deposition) and following Fe layer oxidation. The efficiency of the decomposition of VOCs was tested in the range of 200 to 500 °C, using the method based on infrared spectroscopy (FTIR). The research was focused especially on the analysis of incomplete combustion products, such as CO and oxygen compounds. During the oxidation of isopropanol and n-hexane, in addition to carbon monoxide, species such as acetone, formaldehyde, and acetaldehyde were also detected. The oxidation of formic acid proceeded with only a slight emission of carbon monoxide, unexpectedly the oxidation of benzene proceeded in a similar way, and no other products of the incomplete oxidation were detected. In addition, the CO concentration was lower than in the case of conversion of isopropanol and n-hexane. For the presented solution, complete formic acid oxidation is possible at temperatures below 400 °C, and almost complete oxidation to CO2 of isopropyl alcohol, benzene, and n-hexane was achieved at 500 °C. Additionally, the possibility of conducting the autothermal process of oxidation of VOCs in a fluidised bed, provided that heat recuperation is used, was presented.