Characteristics of Bubbly Flow, Mass Transfer, and CO2 Absorption in a Two-Stage Internal Loop Airlift Reactor Assembly with a Diamond-Shaped Guide Baffle

Airlift reactors are one of the most commonly used gas–liquid reactors in industry. The bubble flow regime, gas holdup, and bubble size are vital for mass transfer and chemical reaction in an airlift reactor. To improve the reactor performance, this study suggests a two-stage internal loop airlift reactor assembly with a diamond-shaped guide baffle. The hydrodynamic parameters, volumetric mass transfer coefficient, and the CO2 removal efficiency in the airlift reactor are measured. The effect of the guide baffle on the bubble flow regime, bubble size, gas holdup, mass transfer coefficient, and CO2 removal efficiency is investigated. Compared with a regular airlift reactor, the proposed airlift reactor features an increase in global gas holdup and volumetric mass transfer coefficients of up to 31.6 and 87.9%, respectively. Additionally, the CO2 removal efficiency increases in the airlift reactor assembly with the guide baffle.