The bubbles produced by a microporous sparger (Dp=40 μm) and a single orifice sparger (Dp=1 mm) at superficial gas velocities ranging from 0.629×10-3 m·s-1to 3.15×10-3m·s-1 were compared in the oxygen cyclohexane system. The results showed that the Sauter mean diameter d32 of the bubbles produced by the microporous sparger were below 1.3 mm, and those by the single orifice sparger were larger than 4.0 mm. The diameters of the bubbles produced by the microporous sparger met the logarithmic normal distribution, and the coalescence of the bubbles was negligible. The gas hold up of the microporous sparger bubbling was relatively higher in the examined superficial gas velocity range. By using the microporous sparger, an cyclohexane oxidation rate of 0.62 mol·m-3·s-1 at a superficial gas velocity of 1.15×10-3 m.s-1 was achieved, which was about 1 fold higher than that performed by using the single orifice sparger.
