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。化学环燃烧是一种很有前途的方法，其中金属氧化物颗粒（即氧载体）用于氧化无氮燃料，以减少氮氧化物排放，提高捕获和封存二氧化碳的效率。然而，载氧粒子的寿命限制了该技术的广泛应用。需要一种方法，在控制颗粒结构的同时，利用燃烧过程氧化燃料。控制颗粒结构可以延长颗粒寿命，减少磨损。金属氧化物纳米颗粒是在类似的气溶胶过程中合成的，但尚未扩展到将金属氧化物颗粒还原为金属。因此，该项目旨在确定能够控制氧化铜（一种常见的氧载体）还原的物理和化学过程。此外，将在社区大学学生转学前进行研究，以提高学生的目标，减少在社区大学开始高等教育的学生在研究生工程学位上的差距。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。该项目的目标是利用自持粉尘火焰，其结构决定了粒子的时间-温度历史，来控制CuO（一种常见的氧载体）的还原过程，以克服化学环燃烧中存在的团聚和磨损问题。这个想法旨在确定能够在快速加热条件下控制还原过程的物理原理，大约每秒0.1- 100万开尔文，而不是在化学循环燃烧的传统等温条件下。定容粉尘火焰实验将量化cuo -气态燃料火焰的火焰结构和极限过程，同时提供时间-温度历史与产品颗粒（即Cu， Cu2O或混合物）结构之间的联系。准一维粉尘火焰将用于细化时间-温度历史，以控制产品的颗粒结构（如粒度、晶粒尺寸和取向等），从而确定颗粒形态和尺寸的形成原因、优选晶面和晶粒尺寸。实验工作将通过实施详细的表面化学和常数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。这种方法将加速化学循环燃烧技术的发展，以提高清洁能源和碳捕获能力。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.