백금계 촉매상에서 산화질소(NO)의 산화 반응속도에 관한 실험 및 모델링 연구

다국어 초록 (Multilingual Abstract)

To improve the NOx conversion over a SCR (selective catalytic reduction) catalyst, the DOC (diesel oxidation catalyst) is usually placed upstream of the SCR catalyst to enhance the fast SCR reaction (4NH₃+2NO+2NO₂→4N₂+6H₂O) using equimolar amounts of NO and NO₂. Here, a ratio of NO₂/NOx above 50% should be avoided, because the reaction with NO₂ only (4NH₃+4NO+O₂→4N₂+6H₂O) is slower than the standard SCR reaction (4NH₃+4NO+O₂→4N₂+6H₂O). In order to accurately predict the performance characteristics of SCR catalysts, it is therefore desired to develop a more simple and reliable mathematical and kinetic models on the oxidation kinetics of nitric oxide over a DOC. In the present work, the prediction accuracy and limit of three different chemical reaction kinetics models are presented to describe the chemicophysical characteristics and conversion performance of DOCs. Steady-state experiments with DOCs mounted on a light-duty four-cylinder 2.0-L turbocharged diesel engine then are performed, using an engine-dynamometer system to calibrate the kinetic parameters such as activation energies and pre-exponential factors of heterogeneous reactions. The reaction kinetics for NO oxidation over Pt-based catalysts is determined in conjunction with a transient one-dimensional (1D) heterogeneous plug-flow reactor (PFR) model with diesel exhaust gas temperatures in the range of 115-525℃ and space velocities in the range of (0.4-6.5)×10?h?¹.

목차 (Table of Contents)

• Abstract
• 1. 서론
• 2. DOC 성능 실험
• 2. 수치적 모델
• 3. 결과 및 고찰
• 4 결론
• Acknowledgement
• References