Bubble characteristics and mass transfer in an airlift reactor with multiple net draft tubes

Abstract

A pilot scale airlift reactor with multiple net draft tubes was developed. The reactor, 29 cm in diameter and 300 cm height, had four modules of double net draft tubes. Bubble size, bubble number, gas holdup, and volumetric mass transfer coefficient were measured under different superficial air velocities. The air velocity had little effect on bubble size but had significant influence on bubble number. A bubble column was also investigated for comparison. The airlift reactor had a higher gas holdup and volumetric mass transfer coefficient than those in the bubble column. The draft tubes in the airlift reactor substantially improved the reactor performance.