CAREER: Sustainable Chemical Synthesis by Plasma-Enhanced Solar Energy

通过可持续工艺生产燃料和化学品是21世纪的关键技术挑战之一。发电或工业过程产生的二氧化碳气体是燃料和化学品生产的潜在碳来源。然而，二氧化碳的活性不是很强，目前还不存在将其转化为燃料和化学品的可行技术。该产品的目标是利用等离子体增强的太阳能将二氧化碳和水转化为燃料和化学品。在提议的过程中，太阳能将二氧化碳气体加热到增加其反应性所需的高温。然后，加热的气体利用电能转化为等离子体，也被称为带电气体。理论上认为，气体的等离子体状态将提高二氧化碳的转化率。这一过程可能是可持续的，而且碳足迹低，因为它使用的是废弃的二氧化碳和丰富的太阳能，产生等离子体所需的电力由太阳能光伏电池提供。该项目还将开发教学手推车，向包括马萨诸塞州洛厄尔地区的西班牙裔K-12学生在内的广泛受众展示受这项研究启发的能源和可持续发展主题。拟议研究的总体目标是对利用集中太阳能驱动反应热化学和非平衡等离子体提高化学反应动力学的二氧化碳和水合成化学和燃料的新工艺有一个基本的了解。等离子体增强太阳能(PESE)结合了太阳能热化学和等离子体科学原理。该项目将对PESE的二氧化碳、水和甲烷的分解和重整进行实验和计算研究。这项研究将检验这样一个假设，即等离子体中自由电子产生的分子激发增加了太阳光子的吸收，从而增强了化学反应动力学。为此，拟议的研究将寻求理解自由电子和光子系统所特有的非平衡能量传输现象，特别是具有可比较的光子和电子能量通量的过程。为了支持研究计划，将开发配备太阳能接收器和流动气体非平衡放电能力的新反应堆系统，并对其进行表征。跨越太阳能和电能输入比例的反应堆实验将在可扩展的工艺条件下进行。将建立新的非平衡能量传输的流体流动和化学动力学模型，并进行实验验证。研究成果旨在揭示PESE过程中能量转换的具体途径，并量化等离子体增强的效果。此外，研究成果还与电子和光子传输具有重要作用的其他领域相关，如激光材料加工、半导体制造和燃烧增强。该项目的教育目标是让从中学到研究生的学生参与全球能源可持续发展主题。为了支持拟议的教育计划，将开发和评估能源工程与可持续发展的模块教学和学习的互动示范车。

The production of fuels and chemicals by sustainable processes is one of key technological challenges of the 21st century. Carbon dioxide gas generated by power generation or industrial processes is a potential source of carbon for fuels and chemicals production. However, carbon dioxide is not very reactive, and no viable technologies for its conversion into fuels and chemicals presently exist. The goal of this product is to convert carbon dioxide and water to fuels and chemical using plasma-enhanced solar energy. In the proposed process, solar energy heats the carbon dioxide gas to the high temperatures needed to increase its reactivity. The heated gas is then converted into plasma, also known as an electrically charged gas, using electrical energy. It is reasoned that the plasma state of the gas will enhance the rate of carbon dioxide conversion. The process is potentially sustainable and has a low carbon footprint because it uses waste carbon dioxide and abundant solar energy, where electricity needed to generate the plasma is provided by solar photovoltaic cells. The project will also develop instructional carts for demonstrating energy and sustainability topics inspired by this research to a broad audience that includes Hispanic K-12 students in the Lowell, Massachusetts area. The overall goal of the proposed research is to develop a fundamental understanding of a new process for synthesis of chemical and fuels from carbon dioxide and water using concentrated solar energy to drive the reaction thermochemistry and non-equilibrium plasma to enhance the chemical reaction kinetics. Plasma-Enhanced Solar Energy (PESE) combines solar thermochemistry and plasma science principles. The project will experimentally and computationally investigate PESE for carbon dioxide, water, and methane decomposition and reforming. The research will test the hypothesis that the molecular excitation produced by free electrons in plasmas increases solar photon absorption leading to enhanced chemical reaction kinetics. Towards this end, the proposed research will seek to understand non-equilibrium energy transport phenomena characteristic of free electron and photon systems, with particular focus on processes with comparable photon and electron energy fluxes. To support the research plan, new reactor systems equipped with solar energy receivers and non-equilibrium electrical discharge capability to flowing gas will be developed and characterized. Reactor experiments spanning the ratio of solar to electrical energy inputs will be performed at scalable process conditions. New fluid flow and chemical kinetics models for non-equilibrium energy transport will be derived and experimentally validated. The research outcomes seek to reveal the specific pathways of energy conversion during PESE processing and quantify the efficacy of plasma enhancement. Additionally, the research outcomes are relevant to other fields where electron and photon transport have essential roles, such as laser materials processing, semiconductor manufacturing, and combustion enhancement. The educational goal of the project is to engage students, from middle school to graduate level, on global energy sustainability topics. To enable the proposed education program, interactive demonstration carts for the modular teaching and learning of energy engineering & sustainability will be developed and assessed.