New Condensed-Phase Approaches for Soot Formation, Aging, and Burnout

针对烟灰形成、老化和燃尽的新凝聚相方法

• 批准号: 0342844
• 负责人: Robert Hurt
• 金额: $ 27.15万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-02-01 至 2008-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0342844&HistoricalAwards=false
• 关键词: New; Condensed; Phase; Approaches; Soot

This project on combustion-generated soot focuses on the complex carbonaceous condensed phases present in flames using concepts and tools developed for other carbon materials in the P.I.'s laboratory. The new tools include direct measurement of dynamic active-site loss at high temperatures and short times, the use of distributed activation energy formulations to understand and model both reactivity loss (aging) and oxidation, and the use of atomic pair-potential simulations to investigate higher polycyclic aromatic hydrocarbon (PAH) interactions. New distributed-site kinetic models are being applied to soot oxidation to resolve the long-standing paradox in the field of apparent power-law kinetics and to unify the kinetic database at high and low temperatures. A key modeling concept is the description of the condensed phases not as solids or liquids, but as polymeric glassy phases with variable nanostructural mobility that governs the transition from coalescence to agglomeration. The project includes a novel experimental task employing new aromatic-rich C/H nanoparticles synthesized in the P.I.'s laboratory as the first physicochemical models for young soot particles in flames. Combustion-generated soot is a respirable, ultrafine particulate material that carries known carcinogens and mutagens and is thus a key atmospheric pollutant. The reduction of soot emissions from diesel engines is a particularly challenging goal for U.S. vehicle manufacturers. Attempts to reduce soot emission from vehicles and furnaces focus on control of the flame chemistry and structure or on capture of particulates and subsequent low-temperature oxidation. For the design of both types of soot-control measures, a better understanding is needed of the structure, properties, and reactivity of the soot particles themselves from their first detection as recognizable condensed organic matter in the early stages of flames to their final release as fractal aggregates of fully carbonized and partially oxidized nanoparticles. This project applies the most modern approaches in carbon science to the understanding and characterization of the various stages of soot formation, evolution, and burnout.

这个关于燃烧产生的烟尘的项目重点是使用为P.I.中的其他碳材料开发的概念和工具来研究火焰中存在的复杂的碳质凝聚相。的实验室。 新的工具包括在高温和短时间内直接测量动态活性位点损失，使用分布式活化能公式来理解和模拟反应性损失（老化）和氧化，以及使用原子对势模拟来研究更高的多环芳烃（PAH）相互作用。 新的分布式网站的动力学模型被应用到烟尘氧化，以解决长期存在的悖论在该领域的表观幂律动力学和统一的动力学数据库在高温和低温。一个关键的建模概念是描述的凝聚相不是固体或液体，但作为聚合物的玻璃相与可变的纳米结构的流动性，支配从聚结到团聚的过渡。 该项目包括一个新的实验任务，采用新的富含芳香族的C/H纳米粒子在P.I.的实验室作为第一个物理化学模型的年轻煤烟颗粒在火焰中。 燃烧产生的烟尘是一种可吸入的超细颗粒物质，携带已知的致癌物质和诱变剂，因此是一种关键的大气污染物。 减少柴油发动机的烟尘排放对美国汽车制造商来说是一个特别具有挑战性的目标。 减少来自车辆和熔炉的烟灰排放的尝试集中在火焰化学和结构的控制上，或者集中在颗粒的捕获和随后的低温氧化上。 对于这两种类型的烟尘控制措施的设计，需要更好地了解烟尘颗粒本身的结构，性质和反应性，从它们在火焰的早期阶段作为可识别的凝聚有机物的第一次检测到它们最终作为完全氧化和部分氧化的纳米颗粒的分形聚集体的释放。 该项目应用碳科学中最现代的方法来理解和表征烟灰形成，演变和燃尽的各个阶段。