Results and discussion
The above promising results motivated the second step of thescale-up methodology; the actual comparison between datagenerated within the tubes bundle and that within a solid wallbubble column. This motivation stems from the finding thatthe proposed arrangement of internals could mimic the solidwall effect as shown above.Independent results of radial gas holdup profiles obtainedby Xue (2004) and Wu (2007) using the optical probe techniquein a separate unit consisting of solid wall column of the same