Numerical simulation on the terminal rise velocity and mass transfer rate of single sub-millimeter bubbles

Y Gas-liquid reactors containing bubbles are intensively used in the chemical industry. However, the gas-liquid mass transfer is usually the rate-limiting step. One possible way to intensify the mass transfer is the application of sub-millimeter bubbles (1-1000 lm) which efficiently increase interfacial area. Literature usually focused on bubbles larger than 1000 lm, and it still needs to be studied whether the frequently-used literature equations for terminal rise velocity and mass transfer can accurately predict the behavior of sub-millimeter bubbles. Therefore, the terminal rise velocity and mass transfer rate of single sub-millimeter bubbles were obtained by numerical simulation. It was found that the literature equations could not accurately predict the behavior of sub-millimeter bubbles over the whole size range. New equations were proposed to improve calculation accuracy, with which the terminal rise velocity and mass transfer rate of sub-millimeter bubbles can be accurately predicted. (C) 2021 Elsevier Ltd. All rights reserved.