An airlift three‐phase reactor in which solid particles are fluidized in the riser by the recirculating liquid was developed. Three particle types of 1.7–8.6 mm in diam., porous and nonporous, spheres and cylinders, were studied in the water–air system. Little effect of the alumina porous particles (apparent density 1.47 × 103 kg/m3) on the gas holdup and liquid superficial velocity was found. On the other hand, the heavier, nonporous ceramic particles (density 2.4 × 103 kg/m3) had a significant effect on both design parameters. The axial distribution of particles was also a function of the particle density and liquid superficial velocity.