The Effect of Pressure on Hydrocarbon Oxidation Through the Negative Temperature Coefficient Regime

该项目（现有NSF项目的延伸）旨在研究压力对低、中温度（550-1000K）下碳氢化合物氧化的影响。在高达20个大气压的压力下获得含有四个或更多碳原子的纯碳氢化合物氧化的动力学信息。这项工作的主要部分将利用最近开发的压流反应堆测试设备。将要进行的实验将提供与烷基过氧自由基反应相关的机理细节（以及压力对这些细节的影响）的解析，并定义双过氧自由基作为分支剂的作用。其他单独的补充性实验也将用于阐明在低温和中温条件下控制直烃和支烃氧化的机理细节。气相色谱、GC/MS和GC/FTIR诊断将用于稳定反应中间体和产物的化学分析，而稳定和自由基的原位测量将使用FTIR光谱进行。具体目标是：(1)获得550至1000K之间纯碳氢化合物在高达20个大气压下氧化的动力学信息；(2)确定压力对各温度区氧化机制的影响，以及压力如何影响各温度区边界；(3)提出并完善烷基过氧自由基反应体系和双过氧自由基反应体系的建模机制。低至中温（低于1000K）的碳氢化合物氧化化学在许多燃烧装置，特别是内燃机的运行中起着重要作用。在某些情况下，占总热量释放的很大一部分，并强烈影响这些器件中较高温度区域的输入边界条件。由于这种装置在高压下工作，因此在远高于大气的压力下进行低温和中低温碳氢化合物氧化的基础研究对于进一步理解许多实际内燃机现象非常重要，包括发动机爆震、预点火燃料分解、污染物形成、和一般的自燃过程。

This program (an extension of a current NSF program) is directed to the study of effects of pressure on hydrocarbon oxidation in low and intermediate (550-1000K) temperature regimes, with acquisition of kinetic information at pressures up to 20 atmospheres for oxidation of pure hydrocarbons containing four or more carbon atoms. A major part of the work will utilize a recently-developed pressurized flow reactor test facility. The experiments to be conducted will provide resolution of mechanistic details (and the effects of pressure on these) associated with alkylperoxy radical reactions and definition of the role of diperoxy radicals as branching agents. Other separate complementary bench-scale experiments will also be utilized to elucidate mechanistic details controlling the oxidation of straight and branched hydrocarbons in the low and intermediate temperature regimes. Gas chromatography, GC/MS, and GC/FTIR diagnostics will be used for chemical analysis of stable reaction intermediates and products, while in-situ measurements of stable and radical species will be carried out using FTIR spectroscopy. Specific objectives are: (1) Obtain kinetic information for oxidation of pure hydrocarbons between 550 and 1000K at pressures up to 20 atmospheres; (2) Determine effects of pressure on oxidation mechanism(s) in each temperature regime and how pressure affects boundaries separating the regimes; and, (3) Suggest and refine mechanisms for modeling the alkylperoxy radical reaction system and the diperoxy radical reaction system. Hydrocarbon oxidation chemistry at low to intermediate temperatures (below 1000K) plays a significant role in operation of many combustion devices, notably internal combustion engines, in some cases accounting for a significant fraction of the overall heat release as well as strongly affecting input boundary conditions for the higher temperature regions in these devices. Since such devices operate at elevated pressures, fundamental research on low and intermediate temperature hydrocarbon oxidation at pressures well above atmospheric is important to furthering the understanding of many practical internal combustion engine phenomena, including engine knock, preignition fuel decomposition, pollutant formation, and general autoignition processes.