Water Spray in Atmospheric Pressure Electrical Discharge Plasma

0932481洛克该奖项根据2009年美国复苏和再投资法案(Public Law 111-5)获得资助。液体(例如水)与等离子体(通常是电离气体)的相互作用在广泛的技术应用和自然现象中发生，包括用于关节镜手术的液态电放电、用于肾结石治疗的碎石术、伤口愈合和消毒、纳米颗粒的合成、等离子体辅助燃烧、用于化学分析的微型传感器、闪电放电、高压电气传输中的腐蚀以及使用等离子体执行器的气流控制。气液等离子体中相对未被探索的等离子体化学反应领域也可能在气液化学反应很重要的重要工业应用中产生广泛影响(例如，空气污染研究和控制以及生产有用的化学品，如甲醇或氢和其他燃料)。这项工作将重点研究气相放电，将小微米尺寸的水滴喷射到等离子体中，因为这种方法已经被证明对于启动各种化学反应，包括过氧化氢的形成，具有潜在的非常高的能源效率。分析等离子体相互作用，特别是在具有小水滴的此类系统中引发的化学反应，对于发展我们对等离子体与凝结液体的一般理解至关重要。这项工作将集中在两个一般情况：1)纯水在Ar和O2载气下的反应产物，包括过氧化氢、氧气和氢气；2)甲烷和水滴在Ar载气下生成甲醇的反应。第一种情况对于在等离子体中引发的所有羟基自由基反应具有基本的重要性，第二种情况虽然在生产液体燃料的能源领域具有重要意义，但提供了一个具有合理描述的反应路径和机理的气液反应的例子。这项拟议的工作将使用一系列实验技术，包括气溶胶颗粒尺寸测量、流动可视化、发射光谱和化学分析，以加深我们对流入等离子体反应器的水滴如何形成羟基自由基等活性化学物种的理解。将对耦合到等离子体化学反应的传输进行数学建模。还将使用分子动力学进行基本分析，以研究电子与凝结水表面的基本相互作用，并协助解释实验研究。预计该项目将有助于发展关于气液环境中的等离子体如何导致活性物种的形成以及它如何影响上述一些应用的基础知识。在跨学科和国际化的环境中，对本科生、博士生和博士后进行化学、机械和电气工程方面的高级教育和培训，并完成对一名年轻的化学工程教职员工的辅导。

0932481LockeThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The interaction of liquid (e.g., water) with plasma (typically an ionized gas) occurs in a wide range of technological applications and natural phenomena including liquid-phase electrical discharge for arthroscopic surgery, lithotripsy for kidney stone treatment, wound healing and disinfection, synthesis of nanoparticles, plasma-assisted combustion, microsensors for chemical analysis, lightning discharges, corrosion in high-voltage electrical transmission and air flow control using plasma actuators. The relatively unexplored field of plasma-chemical reactions in gas-liquid plasma may also have a broad impact in industrially important applications where gas-liquid chemical reactions are important (e.g., air pollution study and control and the production of useful chemicals such as methanol or hydrogen and other fuels). This work will focus on studying a gas-phase electrical discharge with a spray of small micron-size water droplets into the plasma because this approach has been shown to be potentially very energy efficient for initiating a variety of chemical reactions, including the formation of hydrogen peroxide. Analysis of plasma interactions, particularly the chemical reactions initiated in such systems with small droplets of water, is vital to developing our understanding of plasma with condensed liquids in general. This work will focus on two general cases of 1) reaction products, including hydrogen peroxide, oxygen, and hydrogen, from pure water with Ar and O2 carrier gases and 2) formation of methanol from methane and water droplets with Ar carrier. The first case is of fundamental importance for all hydroxyl radical reactions initiated in the plasma and the second, while of significant importance in the energy field for production of liquid fuels, provides an example of gas-liquid reactions with reasonably well characterized reaction pathways and mechanisms. The proposed work will use a range of experimental techniques including aerosol particle size measurements, flow visualization, emissions spectroscopy, and chemical analysis to develop our understanding of how reactive chemical species like hydroxyl radicals are formed by water droplets flowing into a plasma reactor. Mathematical modeling of the transport coupled to the plasma chemical reactions will be conducted. Fundamental analysis using molecular dynamics will also be conducted to study the basic interactions of electrons with condensed water surfaces and to assist in interpretation of the experimental studies. This project is expected to lead to the development of fundamental knowledge on how plasma in gas-liquid environments leads to the formation of reactive species and how it affects some of the applications mentioned above. Advanced education and training of undergraduate students, PhD students, and a postdoctoral researcher in chemical, mechanical, and electrical engineering in an interdisciplinary and international environment will be conducted, and the mentoring of a young faculty member in chemical engineering will be accomplished.