Influence of functional groups on the oxidation of aromatic structures

点击翻译按钮获取中文摘要

In regards of a permanent increase in the global energy demand, a major challenge of the century is the reduction in fossil fuel combustion. Improving combustion systems and replacing conventional fuels by sustainable energy carriers can help in achieving this goal. In this context bio-based octane improvers, i.e. oxygenated aromatics, can play an important role. These compounds can be produced from uneatable lignin and their physico-chemical properties make them ideal fuel blending components with improved anti-knock behavior. In the first phase of the project, the ignition delay times (IDTs) of the most common oxy-aromatics were performed. The combustion behavior of anisole was investigated through an extended experimental and kinetic modeling study. The octane booster properties of series of oxy-aromatic species were examined by the measurement of the ignition delay time of oxy-aromatic/n-pentane blends. These studies revealed the importance of the phenoxy radical and benzaldehyde in the combustion process of the majority of oxy-aromatics. However, detailed studies on these components are scarce and will be consequently in the focus of the second phase of the project. High-pressure gas sampling of reacting phenol and benzaldehyde mixtures during the ignition delay will be performed, giving mole fraction profiles of the stable intermediates of combustion. The speciation experiments coupled with ignition delay times will guide the kinetic modeling and be used as validation targets. In the end, the model will be used to get a deeper insight into the combustion behavior of the crucial intermediates phenoxy radical and benzaldehyde which will impact the understanding of the oxidation scheme of aromatic structures in general. In addition, the positioning effect of different substituents on the aromatic ring on the reactivity will be examined experimentally.