EAPSI: Controlling Gas Evolution and Natural Convection to Optimize the Current Distribution and Energy Efficiency of Electrochemical Cells

电化学为工业规模的结构金属生产提供了一种清洁有效的方法。电力可以用来从原始矿石中生产金属和氧气或硫磺气体，同时避免与传统的基于碳焦的生产方法相关的排放。这个项目试图了解气泡的演化(无论是氧气还是硫磺气体)如何影响电化学电池中阳极(氧化电极)上的电流分布。本课程将应用电化学工程原理，使结果适用于各种化学体系和几何结构。这项研究将与早稻田大学的Takayuki Homma教授和京都大学的Toshiyuki Nohira教授合作进行，他们两人都在界面表征方面拥有丰富的专业知识。这一发现将对设计更节能的电解反应堆至关重要。该项目将利用早稻田大学的高速相机功能，直接观察电解气泡的产生，并关联对电流密度分布的影响。磁流体力学(MHD)对流将作为强化阳极表面传质的工具。京都大学的激光共聚焦扫描显微镜还将用于表征界面现象。与金属硫化物电解相关的质量瑞利数(Ram)的不同值对应的实验结果将在日本实验室内用先前开发的计算方法进行分析。通过建立传质和电流密度分布之间的关联，该项目将有助于设计更高效的电解反应堆，并考虑到工业规模。该奖项由东亚和太平洋夏季学院计划资助一名美国研究生的夏季研究，由NSF和日本科学促进会共同资助。

Electrochemistry provides a clean and efficient way of producing structural metals at industrial scales. Electricity can be used to produce metal and oxygen or sulfur gas from raw ore whilst avoiding the emissions associated with traditional carbon coke-based production methods. This project seeks to understand how bubble evolution (whether oxygen or sulfur gas) affects the distribution of current across the anode (oxidizing electrode) in an electrochemical cell. Electrochemical engineering principles will be applied so that the results will be applicable to a wide variety of chemical systems and geometries. This research will be performed in collaboration with Professor Takayuki Homma at Waseda University and Professor Toshiyuki Nohira at Kyoto University, both of whom have great expertise with interfacial characterization. The findings will be critical designing more energy efficient electrolysis reactors.This project will utilize the high speed camera capabilities at Waseda University to observe directly the production of electrolytic bubbles and correlate the effect on the current density distribution. Magnetohydrodynamic (MHD) convection will serve as a tool to enhance mass transfer at the anode surface. Confocal laser scanning microscopy at Kyoto University will be used additionally to characterize the interfacial phenomena. Experimental results corresponding to different values of the mass Rayleigh number (Ram) relevant for metal sulfide electrolysis will be analyzed with previously developed computational methods within the Japanese labs. By developing a correlation between mass transfer and current density distribution, this project will aid in the design of more efficient electrolysis reactors with the industrial scale in mind.This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Japan Society for the Promotion of Science.