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

电化学为工业规模生产结构金属提供了一种清洁有效的方法。 电力可用于从原矿石中生产金属和氧气或硫磺气体，同时避免与传统的碳焦炭生产方法相关的排放。 该项目旨在了解气泡演变（无论是氧气还是硫气体）如何影响电化学电池中阳极（氧化电极）的电流分布。 电化学工程原理将被应用，使结果将适用于各种各样的化学系统和几何形状。这项研究将与早稻田大学的本间孝之教授和京都大学的野平俊之教授合作进行，他们两人都具有界面表征的丰富专业知识。 这一发现对于设计更节能的电解反应器至关重要。本项目将利用早稻田大学的高速摄像机功能直接观察电解气泡的产生，并将其对电流密度分布的影响联系起来。 磁流体动力学（MHD）对流将作为一种工具，以加强在阳极表面的传质。 京都大学的共聚焦激光扫描显微镜将被用于表征界面现象。 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以前开发的计算方法进行分析。 该项目通过研究质量传递与电流密度分布之间的关系，有助于设计更高效的电解反应器，并考虑到工业规模。该项目是由美国国家科学基金会（NSF）和日本科学促进会（Japan Society for the Promotion of Science）共同资助的东亚和太平洋夏季研究所（East Asia and Pacific Summer Institutes）项目下的一个奖项，用于资助美国研究生的夏季研究。

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.