Effects of sparger design on the gas holdup and mass transfer in a pilot scale external loop airlift reactor

Abstract

Three designs of static spargers were used in a pilot scale external loop airlift reactor to determine their effects on the gas holdup and mass transfer characteristics for an air-water system. Although previous studies involving the effects of sparger design on gas holdup and mass transfer have been reported, no comparative investigations using different spargers in the same pilot scale external loop airlift reactor have been done. In this investigation, the results show that the perforated plate sparger (A) was the best design and produced the best overall gas holdup and mass transfer values when compared to a perforated disk sparger (B) and perforated pipe sparger (C). The perforated pipe sparger produced the worst gas holdup and mass transfer values and also had the worst overall performance for bubble size, flow and distribution. This investigation emphasises the importance of sparger design and that it must be considered in the overall design of an airlift reactor as it has a significant influence on the gas holdup and mass transfer characteristics.