Direct Chemical Kinetics Studies of Elusive Intermediates in Combustion: Ketohydroperoxides

难以捉摸的燃烧中间体的直接化学动力学研究：酮氢过氧化物

• 批准号: 1938838
• 负责人: Brandon Rotavera
• 金额: $ 39.15万
• 依托单位: University of Georgia Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1938838&HistoricalAwards=false
• 关键词: Direct; Chemical; Kinetics; Studies; Elusive

The development of sustainable energy technologies for transportation remains a significant scientific challenge and a high priority for the United States and rest of the world. Given the current and projected reliance on combustion-derived energy for decades to come, a key challenge is increasing the efficiency of next-generation combustion systems. Improvements in efficiency relies on better understanding of chemical reactions that control ignition and heat-release processes in engines. Both are important in optimizing predictive models used to simulate combustion chemistry. Importantly, the efficacy of such models hinges on validation against detailed experimental data. Therefore, the primary activity of the research herein is the study of elementary chemical reactions from a previously unstudied set of molecules, ketohydroperoxides, which are elusive intermediates and central to understanding ignition process. The primary benefit of the present research is the development of new fundamental understanding of chemical reaction pathways and rates relevant to combustion as well as new modeling capabilities to improve the robustness of existing computer simulation models. In addition, the research project encompasses scientific training of Ph.D. students and undergraduate Student Veterans, as well as augmentation of local high school-level educational materials related to sustainable transportation energy. The research herein addresses the knowledge gap on the connection between the molecular structure of intermediate species ketohydroperoxides and products formation during combustion. To achieve this objective, an interdisciplinary team with expertise in chemical synthesis of ketohydroperoxides, derived from cyclohexane combustion, and physical chemistry is formed. Reactions of the three isomer species are studied using two different experiments: multiplexed photoionization mass spectrometry at the Advanced Light Source synchrotron, and speciation from a high-pressure jet-stirred reactor at the University of Georgia. In parallel to experiments, Reaction Mechanism Generator software package is used to generate a new sub-mechanisms for cyclohexane combustion chemistry. The impetus for the present modelling work is that unimolecular decomposition reactions are the only consumption pathways of ketohydroperoxide species in current combustion models. However, other reaction pathways common to alkylperoxy radicals are possible, including reaction with hydroxyl radicals and with oxygen. With complete characterization of reaction pathways, the existing uncertainties of chemical kinetics models can be minimized with accurate predictions of combustion efficiency.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

交通可持续能源技术的开发仍然是美国和世界其他国家的一项重大科学挑战和高度优先事项。鉴于当前和预计未来几十年对燃烧产生的能源的依赖，一个关键的挑战是提高下一代燃烧系统的效率。效率的提高取决于对控制发动机点火和放热过程的化学反应的更好理解。两者对于优化用于模拟燃烧化学的预测模型都很重要。重要的是，此类模型的有效性取决于详细实验数据的验证。因此，本文研究的主要活动是研究以前未研究的一组分子（酮氢过氧化物）的基本化学反应，这些分子是难以捉摸的中间体，对于理解点火过程至关重要。本研究的主要好处是对与燃烧相关的化学反应路径和速率有了新的基本理解，以及新的建模能力，以提高现有计算机模拟模型的稳健性。此外，该研究项目还包括博士生的科学培训。学生和本科生退伍军人，以及增加与可持续交通能源相关的当地高中水平的教育材料。本文的研究解决了中间体酮氢过氧化物分子结构与燃烧过程中产物形成之间联系的知识差距。为了实现这一目标，成立了一个跨学科团队，该团队拥有环己烷燃烧衍生的酮氢过氧化物化学合成和物理化学方面的专业知识。使用两个不同的实验研究了三种异构体物质的反应：先进光源同步加速器的多重光电离质谱分析，以及佐治亚大学高压喷射搅拌反应器的形态形成。在实验的同时，反应机制生成器软件包用于生成环己烷燃烧化学的新子机制。目前建模工作的动力是单分子分解反应是当前燃烧模型中酮氢过氧化物物质的唯一消耗途径。然而，烷基过氧自由基常见的其他反应途径也是可能的，包括与羟基自由基和与氧的反应。通过对反应路径的完整表征，可以通过准确预测燃烧效率来最大限度地减少化学动力学模型现有的不确定性。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Fragmentation mechanisms from electron-impact of complex cyclic ethers formed in combustion

• DOI: 10.1016/j.ijms.2020.116342
• 发表时间: 2020-08
• 期刊: International Journal of Mass Spectrometry
• 影响因子: 1.8
• 作者: Alanna L. Koritzke;Kelsey M. Frandsen;M. Christianson;Jacob C. Davis;Anna C. Doner;Alexander Larsson;Josiah Breda-Nixon;B. Rotavera