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

California State University-Long Beach Foundation, Long Beach CA

Investigators

Abstract

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.