Influence of molecular structure of various hydrocarbons on soot formation

各种碳氢化合物的分子结构对烟灰形成的影响

• 批准号: EP/I006044/1
• 负责人: Nicos Ladommatos
• 金额: $ 22.52万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2011
• 资助国家: 英国
• 起止时间: 2011 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FI006044%2F1
• 关键词: Influence; molecular; structure; various; hydrocarbons; Influence; molecular; structure; various; hydrocarbons

Many types of combustion system emit particles into the atmosphere which are known to be a major hazard due to their toxicity to human health, particularly the respiratory and cardiovascular systems. The smaller particles (less than about 100nm in size) are believed to be the most hazardous, as they can penetrate deep into the human lung. The purpose of this proposal is to gather scientific information on how the structure of fuel molecules affects the production of soot and particulates. During the next 10 to 20 years one can anticipate increasing interest in synthetic fuels which use molecules specifically developed to burn more efficiently and cleanly. The development of such molecules will require knowledge of how different molecular structures affect the production of harmful particulates and other emissions. Such clean fuels may be derived from fossil sources such as coal or increasingly from biomass (starches, sugars, and cellulosic materials) using chemical or biological conversion methods. The proposed project aims to determine in detail which features of a molecule's structure are responsible for producing more soot than others. The project relies on a new methodology which has not been used by the combustion research community previously to any significant extent. The methodology involves the replacement within a hydrocarbon molecule of selected commonplace 12C atoms with 13C atoms carrying a stable isotope label (extra neutron) which survives combustion intact, without altering the chemical and transport properties of the molecule. This label , which can be detected in the soot particles, provides a unique ability to determine which atoms or group of atoms of a molecule become soot particles. Two extensive series of experiments will be conducted, the first on a laminar diffusion flame and the second on a diesel engine. Unlike a diesel engine, the laminar flame allows the principal influences on soot formation to be chemical ones, by eliminating spray formation and evaporation and the effects of turbulent mixing and intermittent combustion. A laminar flame also allows readily the sampling and analysis of the contents of its envelope and it permits the introduction of controlled amounts of oxygen and other diluents at its base so as to study how these diluents affect soot formation. The second series of experiments will be on a diesel engine which represents a commonplace practical combustion system. Although the fuel spray in a diesel engine is less accessible, a diesel engine it is a truly realistic environment in which the pollutant particulate is formed. A total of 15, 13C-labelled fuel molecules have been selected to study the effect of their structure on soot and particulate formation. These 15 molecules have a wide range of structural features that could potentially affect soot and particulate formation and the 13C labelling method will allow the influences of these features to be evaluated. By the completion of the project it is envisaged that the knowledge gained could guide the production of future synthetic fuels so that the molecules they contain result in less soot and toxic particulates when combusted.

许多类型的燃烧系统将颗粒散发到大气中，由于它们对人类健康的毒性，尤其是呼吸道和心血管系统，它们被称为主要危害。据信较小的颗粒（小于100nm的大小）是最危险的，因为它们可以深入到人类肺部。该提案的目的是收集有关燃料分子结构如何影响烟灰和颗粒物的产生的科学信息。在接下来的10到20年中，人们可以预期对合成燃料的兴趣增加，这些燃料使用专门开发的分子来更有效，清洁。这种分子的发展将需要了解不同的分子结构如何影响有害颗粒物和其他排放的产生。这种干净的燃料可以源自化石源，例如煤炭，也可以源于使用化学或生物学转化方法的生物质（淀粉，糖和纤维素材料）。拟议的项目旨在详细确定分子结构的哪些特征比其他分子产生更多的烟灰。该项目依赖于一种新方法，该方法尚未在燃烧研究社区以前在很大程度上在任何程度上使用。该方法涉及在选定的常用12c原子的碳氢化合物分子内替换，其含有稳定的同位素标签（Extra Neutron），该原子在不改变分子的化学和转运特性的情况下幸存下来，该稳定的同位素标签（额外的中子）。该标签可以在烟灰颗粒中检测到，提供了独特的能力，可以确定分子的原子或一组变为烟灰颗粒。将进行两次广泛的实验，第一个实验在层流扩散火焰中，第二个是在柴油发动机上进行的。与柴油发动机不同，层状火焰可以通过消除喷雾形成和蒸发以及湍流混合和间歇性燃烧的影响，使对烟灰形成的主要影响成为化学形成。层状火焰还可以轻松地对其包膜内容物进行采样和分析，并允许在其底部引入受控量的氧气和其他稀释剂，从而研究这些稀释剂如何影响烟灰的形成。第二系列实验将是在柴油发动机上，该发动机代表了常见的实用燃烧系统。尽管柴油发动机中的燃油喷雾剂较低，但柴油发动机是一个真正逼真的环境，形成了污染物颗粒物。总共选择了15个标签的燃料分子来研究其结构对烟灰和颗粒形成的影响。这15个分子具有广泛的结构特征，可能会影响烟灰和颗粒形成，而13C标记方法将允许评估这些特征的影响。通过项目的完成，可以预见，所获得的知识可以指导未来的合成燃料的产生，从而使它们所含的分子在燃烧时会导致烟灰和有毒的颗粒。