EN
The overall gas hold-up of a pilot plant scale internal loop airlift reactor was studied in presence of different alcohols in varied concentration. It has been observed that these simple alcohols can enhance overall gas hold-up of the airlift assembly possibly due to formation of protective thin layer over smaller gas bubbles thereby reducing chance of their coalescence. As the alcohols can be used as food source for the micro organisms present in the system, this green and environment friendly process have potential to replace usage of hazardous surfactants often used for enhancing overall hold-up in order to obtain desired mass transfer characteristics. An empirical relationship encompassing overall gas hold-up of the reactor as a function of superficial gas velocity and alcohol concentration is also developed.