An Experimental Investigation of the Ignition and Oxidation of Biodiesel-Relevant Alkyl Esters at Engine Conditions

1032453 Oehlschlaeger在该项目中，将在类似发动机的条件下，以空气作为氧化剂，在高压下对广泛的（C3-C18）生物柴油相关烷基酯的点火和氧化动力学进行实验激波管研究。激波管测量的宏观氧化动力学目标，点火延迟时间和一氧化碳的时间历程，将净烷基酯，烷基酯共混物，和大酯与石油柴油替代混合物的共混物。这些测量将提供关于不同的烷基酯的整体反应性和氧化过程的时间演变的信息，允许开发和评估这些化合物的动力学机制，和测试的PI？的中心假设，这些烷基酯的有机结构将强烈影响反应活性和反应途径。特别是，CO的测量将提供洞察的负温度系数（NTC）制度，其中CO生产点火前预期的烷基酯的燃烧行为。此外，这些测量将深入了解生物柴油和化石柴油之间的动力学差异，从而评估向生物柴油过渡对发动机的影响。建议的实验代表的第一CO测量烃类燃料在冲击加热的气体和建议的实验为大酯（C11-C18）代表第一激波管测量酯的这种size.Intellectual MeritThe点火和氧化动力学的生物柴油相关的酯在高压发动机的条件下没有深入研究。随着未来生物柴油燃料的大规模商业化，描述其氧化的动力学机制是需要的开发和优化的高效清洁燃烧发动机上运行的生物柴油。宏观动力学目标（点火延迟和CO时间历程）将有助于酯氧化机制的发展，提供不同有机酯结构对氧化的影响的基本理解，并提供生物柴油与化石衍生物的差异和相似性的理解。拟议的研究旨在提供与生物柴油相关的大型烷基酯的点火和氧化动力学的实验见解，目前尚不存在，并将对燃烧动力学建模社区产生广泛影响，这些社区需要这些目标进行机制开发和验证，发动机社区需要基本了解生物柴油的反应性，生物柴油和化石柴油的差异，以及用于发动机模拟的简化动力学模型。拟议的研究计划与教育和推广活动密切相关。研究生，本科生和高中生将被招募，指导，教育，并提供学习最先进的实验技术和探索现代能源问题的机会。将努力吸引传统上代表性不足群体的学生。研究课题和成果将被纳入本科和研究生课程。能源介绍也将在网上提供。

1032453OehlschlaegerIn this project an experimental shock tube investigation of the ignition and oxidation kinetics of a wide range (C3-C18) of biodiesel-relevant alkyl esters at engine-like conditions, high pressure with air as the oxidizer will be conducted. Shock tube measurements of macroscopic oxidation kinetic targets, ignition delay times and carbon monoxide time-histories, will be made for the neat alkyl esters, alkyl ester blends, and blends of large esters with petroleum-diesel surrogate mixtures. These measurements will provide information about the overall reactivity of the different alkyl esters and the temporal evolution of the oxidation process, allowing development and assessment of kinetic mechanisms for these compounds, and a test of the PI?s central hypothesis that the organic structure of these alkyl esters will strongly influence reactivity and reaction pathways. In particular, the measurement of CO will provide insight into the combustion behavior of alkyl esters in the negative temperature coefficient (NTC) regime, where CO production prior to ignition is expected. Additionally, these measurements will provide insight into the kinetic differences between bio- and fossil-derived diesels, allowing assessment of the impact a transition to biodiesel will have on engines. The proposed experiments represent the first CO measurements for hydrocarbon fuels in shock-heated gases and the proposed experiments for large esters (C11-C18) represent the first shock tube measurements for esters of this size.Intellectual MeritThe ignition and oxidation kinetics of biodiesel-relevant esters at high-pressure engine-like conditions have not been deeply investigated. With the possible future wide scale commercialization of biodiesel fuels, kinetic mechanisms describing their oxidation are needed for the development and optimization of high-efficiency clean combustion engines operating on biodiesel. Macroscopic kinetic targets (ignition delay and CO time-histories) will aid in the development of ester oxidation mechanisms, provide fundamental understanding on the influence of different organic ester structure on oxidation, and provide an understanding of the differences and similarities biodiesels have with their fossil-derived counterparts.Broader ImpactThe broad societal impact of a transition to biofuels could be enormous. The proposed research seeks to provide experimental insight into the ignition and oxidation kinetics of large alkyl esters relevant to biodiesel which currently does not exist and will have broad impact on the combustion kinetic modeling community who need such targets for mechanism development and validation and the engine community who need basic insight into the reactivity of biodiesel, the differences of bio- and fossil-diesel, and reduced kinetic models for engine simulations. The proposed research program is closely coupled to educational and outreach activities. Graduate, undergraduate, and high school students will be recruited, mentored, educated, and provided the opportunity to learn state-of-the-art experimental techniques and explore a modern energy problem. Efforts will be made to attract students from traditionally underrepresented groups. Research topics and results will be integrated into undergraduate and graduate courses. Energy presentations will also be made available online.