Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
EXPERIMENTAL STUDY ON CONVECTIVE MASS TRANSFER OF HYDROGEN DURING ELECTROLYSIS
Submission Author:
Clauber Andre Ferasso , RS
Co-Authors:
Jeferson Diehl de Oliveira, Clauber Andre Ferasso, Luciane Calabria, Cesar Pandolfi, Jacqueline Copetti, Elaine Maria Cardoso, Lirio Schaeffer
Presenter: Jeferson Diehl de Oliveira
doi://10.26678/ABCM.ENCIT2022.CIT22-0078
Abstract
This investigation is devoted to analyzing hydrodynamic behavior and mass transfer performance in water electrolysis processes in an alkaline solution (30%wt KOH) under different current densities, using vertical stainless steel 304 electrodes (20 mm X 60 mm) with a separation of 20 mm between them in an electrolyzer made of glass (80 mm X 80 mm X 80 mm). An optical flow method is implemented to study the velocity field of hydrogen bubbles based on image sequences captured by a CCD camera with a 67.2 m/(pixel length). In this case, the influence of current density varying between 190 and 650 A/m2 was investigated. The experimental results show that the velocity distribution in most regions of the electrolyzer is dominated by two asymmetry bubble buoyancy-induced flow patterns caused by hydrogen and oxygen plumes. The increasing velocity and vorticity fields are observed in low depth regions, generating an increase in turbulence in the electrolyte. Nevertheless, the average velocity decreases for higher current densities due to increased turbulence zones. Complex structures generated by turbulence considerably affect bubble dynamics. Such results facilitate the understanding and the dynamics of the transport phenomena of hydrogen bubbles in the electrolyzer.
Keywords
Hydrogen Generation, renewable energy, Electrolysis, Velocity field
