INFLUENCE OF THE GAS-LIQUID SEPARATOR DESIGN ON HYDRODYNAMIC AND MASS-TRANSFER PERFORMANCE OF SPLIT-CHANNEL AIRLIFT REACTORS

Three geometric configurations of gas-liquid separators were used in s plit-channel airlift reactors (0.1 m(3) liquid volume; riser-to-downco mer cross-sectional area ratio = 0.7; aspect ratio = 3.6) to test the effect of geometry on hydrodynamic performance and oxygen transfer beh aviour. For otherwise fixed conditions, the design of gas-liquid separ ators affected the induced liquid circulation rate, the depth of penet ration of the bubble layer in the downcomer, the gas holdup in the dow ncomer, the mixing time and the overall volumetric gas-liquid oxygen t ransfer coefficient. The gas holdup in the riser was only marginally a ffected by the design of the separator. The impact of the various sepa rator designs on hydrodynamic behaviour could be explained as emanatin g from a combination of the gas-liquid separating ability of the desig n and its hydraulic resistance.