CAREER: Controlled Copper Oxide Reduction Using Inverse Dust Flames for Improved Chemical Looping Combustion

正在开发清洁能源和碳捕获技术，以有效地减少对环境的影响。化学循环燃烧是一种利用金属氧化物颗粒(即氧载体)氧化无氮燃料的方法，以减少氮氧化物的排放，提高二氧化碳的捕集和隔离效率。然而，氧气载体颗粒的寿命限制了该技术的广泛使用。需要一种方法，其中使用燃烧过程来氧化燃料，同时控制颗粒的结构。控制颗粒结构将延长颗粒寿命，减少磨损。金属氧化物纳米颗粒是通过类似的气溶胶过程合成的，但还没有扩展到将金属氧化物颗粒还原为金属。因此，该项目寻求确定能够控制常见氧气载体氧化铜还原的物理和化学过程。此外，将在社区大学学生转学前引入研究，以提高学生的目标，这将缩小在社区大学接受大专教育的学生在研究生工程学位方面的差距。这些努力将提高发电能力，同时减少对环境的影响，并增加技术人员的多样性。该项目的目标是使用自持粉尘火焰，其结构决定了颗粒的时间-温度历史，以控制常见氧气载体CuO的还原过程，以克服化学循环燃烧中存在的结块和磨损问题。这个想法试图确定能够在快速加热条件下控制还原过程的物理条件，约为每秒0.1-100万开尔文，而不是传统的化学循环燃烧的等温条件。定容粉尘火焰实验将量化CuO气体燃料火焰的火焰结构和限制过程，同时提供时间-温度历史和产物颗粒(即，铜、Cu2O或混合物)结构之间的联系。准一维粉尘火焰将被用来修正时间-温度历史，以控制产品的颗粒结构(例如，颗粒尺寸、颗粒尺寸和取向等)。从而确定颗粒形态和大小、择优晶面和颗粒尺寸的形成原因。实验工作将通过实施详细的表面化学和常N蒙特卡罗模型来补充，以了解燃烧化学、气溶胶物理和颗粒结构之间的相互作用。这一方法将加速化学循环燃烧技术的开发，以提高清洁能源和碳捕获能力。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Clean energy and carbon capture technologies are being developed to reduce environmental impact in an efficient manner. Chemical looping combustion is one promising approach where metal oxide particles (i.e., oxygen carriers) are used to oxidize fuel without nitrogen present to reduce nitrogen oxide emissions and improve efficiency of capturing and sequestering carbon dioxide. However, the longevity of the oxygen carrier particles limits the technologies widespread use. An approach is needed where the combustion process is used to oxidize fuel while controlling the structure of the particles. Control of the particle structure will extend particle longevity and reduce attrition. Metal oxide nanoparticles are synthesized in a similar aerosol process but have not been extended to reduce metal oxide particles to metal. Thus, this project seeks to identify the physical and chemical processes that will enable control of copper oxide, a common oxygen carrier, reduction. In addition, research will be introduced to community college students pretransfer to improve student goals that will reduce gaps in postgraduate engineering degrees for students that start post-secondary education at community colleges. These efforts will improve the ability to produce power while decreasing environmental impact and increase the diversity of the technical workforce.The goal of this project is to use self-sustaining dust flames, whose structure dictates the particle time-temperature history, to control the reduction process of CuO, a common oxygen carrier, to overcome agglomeration and attrition issues present in chemical looping combustion. This idea seeks to determine the physics that will enable reduction process to be controlled under the fast heating conditions, about 0.1-1.0 million degrees Kelvin per second, rather than the traditional isothermal conditions in chemical looping combustion. Constant volume dust flame experiments will quantify the flame structure and limiting processes of CuO-gaseous fuel flames, while providing a link between time-temperature history and product particle (i.e., Cu, Cu2O, or mixture) structure. Quasi-1D dusty flames will be used to the refine time-temperature history to control the product particle structure (e.g., particle size, grain size and orientation, etc.) such that the cause for the formation of particle morphology and size, preferred crystal faces, and grain size is determined. Experimental work will be complemented by implementing detailed surface chemistry and a constant-N Monte Carlo models to understand the interplay between combustion chemistry, aerosol physics, and particle structure. This approach will accelerate chemical looping combustion technology development to improve clean energy and carbon capture capabilities.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.