| Popis: |
Volatile organic compounds (VOCs) are toxic compounds recognized as important air pollutants. Therefore, the development of efficient, economically acceptable methods to reduce their emissions into environment is highly required. Among the existing conventional and advanced methods of the VOC removal, catalytic oxidation is one of the most attractive technologies for the abatement of low VOCs concentrations. The aim of this work was preparation, characterization and evaluation of catalytic performances of the mixed manganese-based oxides (e.g. Mn-Cu oxides) for oxidation of toluene. The first part of work involved the synthesis of the Mn-Cu mixed oxide in the powder form using method of precipitation, the development of methods for washcoating the catalytically active metal components on a metallic monolithic carrier and the characterization of the prepared catalysts. In the second part of work the steady-state kinetic measurements of toluene oxidation were made using both a fixed bed reactor and metallic monolith reactor. Reaction of toluene oxidation was performed within a temperature range of 100- 275°C and at different space times. The inlet concentration of toluene at the entrance of the reactor and volume ratio of toluene and oxidant were kept constant. Special attention was paid to the analysis and modelling of the experimental reactors used in this research. The experimental results revealed a very high efficiency of the prepared catalysts for total oxidation of toluene. The reaction temperature T50 corresponding to 50% of the toluene conversion was observed at temperatures of ca. 150°C for the powder catalyst (0.05 g) and at temperatures of 180-215°C for the monolith form of catalyst (0.0024 g), depending on the space times inside the reactor. The simple mathematical models, such as one-dimensional (1D) pseudo-homogeneous model of the fixed bed reactor and the one-dimensional (1D) heterogeneous model of the monolith reactor were applied to describe and compare catalytic performances of both reactors. A very good agreement was obtained between the model predictions and the experimental data obtained using laboratory reactors, indicating the acceptability of the applied models for the description of the experimental system used in this research. |
