Primary and Secondary Aerosol Formation in Low-Temperature Combustion of Alcohol Biofuels

酒精生物燃料低温燃烧中的初级和次级气溶胶形成

• 批准号: 2125064
• 负责人: Rawad Saleh
• 金额: $ 42.94万
• 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: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2125064&HistoricalAwards=false
• 关键词: Primary; Secondary; Aerosol; Formation; Low

A desire for environmentally cleaner automobiles has led to the idea of using biologically derived fuels in engines that operate at lower temperatures. Such systems would minimize exhaust emissions that contribute to photochemical smog. Next-generation passenger vehicles equipped with low-temperature combustion engines are expected to appear in larger numbers soon. However, the environmental impacts associated with these vehicles have not yet been completely assessed. This research project combines techniques from atmospheric and combustion sciences to determine the air-quality and climate impacts of pollutants emitted from the low-temperature combustion of advanced biofuels. Results from this research will be valuable for designing efficient emission-control strategies for these vehicles in advance of their deployment in the market. The project will afford education-through-research opportunities for undergraduates and high-school summer interns, and the research team will develop lesson plans on biofuels, renewable energy, and air quality to be implemented in high-school STEM curricula. By working with schools in Athens Clarke County that have high enrollments of minorities and economically disadvantaged students, these educational programs will increase the inclusion of such groups in STEM education.Low-temperature combustion reduces the production of two key pollutants compared to conventional diesel combustion: Nitrogen oxides (NOx) and black carbon. However, it is not clear how low-temperature combustion, especially when utilizing alcohol biofuels, affects the formation of primary and secondary organic aerosol – both important pollutants in terms of their effect on air quality and the climate system. This research will utilize controlled combustion experiments that will elucidate the connections between the molecular structure of biofuels and the gas-phase reactions leading to aerosol formation within the ranges of temperatures, pressures, and equivalence ratios encountered in low-temperature combustion engines. To isolate the effects of fuel structure on aerosol formation and properties, the investigation will involve three alcohol biofuels and their hydrocarbon analogues: 1-butanol and n-butane, iso-pentanol and iso-pentane, and cyclopentanol and cyclopentane. The aerosol emissions will be characterized for their properties that dictate their air-quality and climate impacts, including chemical composition as well as microphysical and optical properties. Furthermore, the emissions will be sent through an oxidation flow reactor that simulates atmospheric oxidation, and the secondary organic aerosol formed will be characterized. In parallel, the gaseous emissions will be speciated to identify intermediates implicated in primary organic aerosol formation as well as prominent secondary organic aerosol precursors, which will shed light on the connections between gas-phase combustion chemistry and aerosol formation.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.

对环境清洁汽车的渴望导致了在较低温度下运行的发动机中使用生物学衍生的燃料的想法。这样的系统将最大程度地减少导致光化学烟雾的耗尽排放。预计配备低温组合发动机的下一代乘用车将很快出现。但是，尚未完全评估与这些车辆相关的环境影响。该研究项目结合了大气和组合科学的技术，以确定从晚期生物燃料的低温组合发出的污染物的空气质量和气候影响。这项研究的结果对于在市场部署之前为这些车辆设计有效的排放控制策略将很有价值。该项目将为大学生和高中暑期实习生提供教育 - 研究的机会，研究小组将制定有关在高中STEM课程中实施的生物燃料，可再生能源和空气质量的课程计划。通过与雅典克拉克县的学校合作，少数群体和经济困扰的学生入学，这些教育计划将增加此类群体在STEM教育中的包含。与常规柴油组合相比，低温组合减少了两种关键污染物的产生：氮氧化物（NOX）和黑碳。但是，尚不清楚温度组合的组合多么低，尤其是在使用酒精生物燃料时会影响原代和次要有机气溶胶的形成 - 在其对空气质量和气候系统的影响方面，这都是重要的污染物。这项研究将利用受控的组合实验，以阐明生物燃料的分子结构与导致范围内气溶胶形成的气相反应之间的连接。低温组合引擎中遇到的温度，压力和等效比。为了隔离燃料结构对气溶胶形成和特性的影响，该投资将涉及三个酒精生物燃料及其碳氢化合物类似物：1-丁醇和N-丁烷，ISO-戊烷醇和Iso-pentane，以及环戊烷醇和环戊烷。气溶胶排放的特征是其特性决定其空气质量和气候影响，包括化学成分以及微物理和光学特性。此外，排放将通过模拟大气氧化的氧化流动反应器发送，并且形成的次级有机气溶胶将被表征。同时，将指定气体排放量以确定在主要有机气溶胶形成中实施的中间体以及突出的次要有机气溶胶前体，这将揭示出气相组合化学和气溶胶形成之间的联系，这反映了NSF的法定任务和诚实的支持，这是通过评估良好的构成的良好的支持。

项目成果

Two-stage aerosol formation in low-temperature combustion

• DOI: 10.1016/j.fuel.2021.121322
• 发表时间: 2021-11
• 期刊: Fuel
• 影响因子: 7.4
• 作者: O. E. Hajj;Khairallah Atwi;Zezhen Cheng;Alanna L. Koritzke;M. Christianson;N. S. Dewey;B. Rotavera;R. Saleh

Effect of Torrefaction on Aerosol Emissions at Combustion Temperatures Relevant for Domestic Burning and Power Generation

• DOI: 10.1021/acsearthspacechem.2c00251
• 发表时间: 2022-10
• 期刊: ACS Earth and Space Chemistry
• 影响因子: 3.4
• 作者: Charles Perrie;Chase K. Glenn;Gregory Reed;Tret C. Burdette;Khairallah Atwi;Omar El Hajj;Zezhen Cheng;Kruthika V. Kumar;A. Frossard;S. Mani;R. Saleh