Pressure and gas density effects on bubble break-up and gas hold-up in bubble columns

The influence of both pressure and gas molecular weight on bubble size and gas hold-up in a bubble column was studied. It was determined that gas hold-up increases whereas the bubble size decreases with increasing gas density at a constant superficial gas velocity. It was also determined that these findings cannot be explained by the influence of gas density on bubble formation as is assumed in the literature. A new explanation for the results is presented, based on experimentally obtained evidence that gas density influences bubble break-up.