SUSCHEM: Effects of renewable biofuels on soot concentrations and soot particle nanostructure

1604983 - McEnallyBiofuels有可能满足美国的能源需求，它们是一种国内能源，减少了对进口石油的依赖。 它们是可以减少二氧化碳净排放的绿色燃料。 对于这个项目来说，最重要的是，它们在燃烧时排放的污染物，特别是烟尘颗粒量较少。 烟尘排放会增加大气中的颗粒物，对健康产生慢性影响，每年在全世界造成数百万人死亡。 此外，煤烟颗粒吸收阳光并直接加热大气;最近的证据表明，它们是全球变暖的第二大贡献者。 该项目将产生基本的燃烧数据，工程师可以利用这些数据设计更清洁的燃烧设备，政策制定者可以利用这些数据选择效益最大的生物燃料。更具体地说，将少量生物燃料添加到基准甲烷火焰中，然后测量随后的物种浓度和颗粒特性变化，从而研究生物燃料的燃烧行为。 这种燃料扰动策略允许在相同的燃烧条件下研究所有的生物燃料，从而可以直接比较它们形成烟灰颗粒和其他污染物的倾向。 因此，测量结果将直接对潜在生物燃料的排放效益进行排序。 此外，燃料扰动策略只需要非常小的样本进行测试，这是至关重要的，因为在开发阶段，燃料往往只有有限的数量。 一个很好的例子是耶鲁大学的另一个研究小组将从海藻油中以毫升为单位生产生物柴油。 火焰中的颗粒浓度将通过激光诱导白炽和色比高温计测量。 将通过在热泳探针上收集颗粒，然后用电子显微镜和其他表面科学技术对其进行分析来测量颗粒尺寸和形态。 物质浓度将通过用微探针提取气体样品，然后用在线光电离质谱法进行分析来测量。 物种的结果将提供深入了解的氧化和污染物形成机制的生物燃料，并作为数据验证这些机制的计算机模拟。 对这些机制的一般理解将有助于确定许多可能的生物燃料中哪些具有最吸引人的特性，计算机模拟将导致实践工程师可以使用的设计工具。

1604983 - McEnallyBiofuels can potentially meet America's energy needs and they are a domestic source of energy that lessens dependence on imported oil. They are green fuels that can reduce net emissions of carbon dioxide. Most importantly for this project, they emit smaller amounts of most pollutants when burned, especially soot particles. Soot emissions contribute to particulate loadings in the atmosphere that produce chronic health effects and cause millions of deaths worldwide each year. Moreover, soot particles absorb sunlight and directly heat the atmosphere; recent evidence suggests they are the second largest contributor to global warming. This project will generate fundamental combustion data that engineers can use to design cleaner-burning devices and that policymakers can use to select the biofuels that offer the greatest benefits.More specifically, the combustion behavior of biofuels will be studied by adding them in small amounts to a baseline methane flame, then measuring the subsequent changes in species concentrations and particle properties. This fuel perturbation strategy allows all of the biofuels to be studied under the same combustion conditions, such that their propensity to form soot particles and other pollutants can be directly compared. Thus the measurements will produce a direct ranking of the emission benefits of potential biofuels. Furthermore, the fuel perturbation strategy requires only very small samples for testing, which is critical since fuels are often only available in limited quantities during the development phase. A good example are biodiesel fuels that will be generated from algal oils in milliliter quantities by another research group at Yale. Particle concentrations in the flames will be measured by laser-induced incandescence and color-ratio pyrometry. Particle size and morphology will be measured by collecting particles on thermophoretic probes and then analyzing them with electron microscopy and other surface science techniques. Species concentrations will be measured by extracting gas samples with a microprobe and then analyzing them with on-line photoionization mass spectrometry. The species results will provide insight into the oxidation and pollutant formation mechanisms for the biofuels, and serve as data for validating computer simulations of these mechanisms. A general understanding of these mechanisms will help identify which of the many possible biofuels have the most attractive properties, and computer simulations will lead to design tools that can be used by practicing engineers.