Hydrogen bubble characterization in alkaline water electrolysis

HYDROGEN BUBBLE CHARACTERIZATION IN ALKALINE WA'I['ER ELECTROLYSIS (Master of Applied Science, 2000) Daniel Lumanauw Department oi Metailurgy and Materiais Science University of Toronto This thesis investigates the process of bubble evolution in water elec~olysis. Little experimentd data exists for conditions found in commercial electrolyzers so thar the pnmary focus was to develop expenmental technologies. which would allow rneasurements under these conditions. The project was successful in demonstrating that Image Analysis and Laser Scattering Particle Size Analysis were useful in analyzing the bubble evolution phenornena. Hydrogen bubbles were produced from water electrolysis in 1 M &CO3 at room tempenture and pressure using smooth screen, rough screen, crystalline plate, and morphous-alloy plate electrodes. Plate electrodes produced more uniform bubble size distribution than screen type cathodes. The mean bubble size, for applied current density of 100 to 250 mA/cm2, decreased in the order of plate electrodes> rough screen > smooth screen electrodes. Bubble size increases with decrease in electrolyte flownte and increase in current density (except for the rough screen electrode). Firstly, 1 would like to thank God for ail opportunities and blessing He has given to me. 1 would like to say rhank you to my supervison Dr. D. W. Kirk and Dr. S. J. Thorpe for d l of their guidance, and Stuart Encrgy System Corp., for initiating and supporting this resexch project. I would like to thank Dr. D. Rubisov for his technical assistance in the operation of the particle size analyzer. I would like to acknowledge the mernben of Electrochemisuy and Surface Engineering Group: Anson Sinanan. Paulo Borges. and Arthur Pismenny for their stimulating discussions of research matters relating to my thesis topic. I give my regards to good friends of mine: Marc Dupere. Johan Susanto, and Rudi Budiarto. Finally, would like to thank my family for their many years of supports.