The principal of gas stripping is t

The principal of gas stripping is the removal of fluid's ingredients through bubbling gases (air, steam,...). The ingredients are transferred into the gas because ingredient's vapour pressure is higher in the fluid phase than in the gas phase. The fluid is directed in a counter flow through a so called stripping-column.

Gas stripping is normally used for waste water treatment or crude oil processing, but it is also an applicable technique for in situ butanol recovery during ABE fermentation. ABE production is associated with the generation of H2 and CO2. To make the recovery process more economically, these gases are used for in situ recovery by gas stripping to remove butanol. The gases are bubbled through the fermenter and then cooled in a condenser. As a result of bubbling through the fermentation broth ABE is captured and consequently condensed and collected in a receiver vessel. The cleaned gas is recycled back to the fermenter. Gas stripping is continued until all the sugar is utilized by the clostridia or the fermentation is determinated. Figure 4 shows three different possible applications of simultaneous fermentation and product recovery by gas stripping.