Why do fermenters use compressed air?

The main reasons for the use of compressed air in fermenters include the following:

oxygen transfer: During fermentation, microorganisms need oxygen for metabolic activities, especially in aerobic fermentation. By injecting compressed air into the fermentation tank, oxygen can be effectively transferred to the fermentation broth to meet the needs of microbial growth and metabolism.

Stirring effect: compressed air can form bubbles in the fermentation tank. These bubbles produce stirring effect during the rising process, helping to evenly distribute heat, nutrients and microorganisms, and maintain a suitable fermentation environment.

Increase gas exchange: The injection of compressed air can also increase the gas exchange in the fermenter, help to discharge the carbon dioxide and other waste gases, and maintain the pressure balance in the fermenter.

Temperature Control: In some cases, by adjusting the temperature and flow of compressed air, it is possible to assist in controlling the temperature within the fermenter to keep it within a suitable range.

Promote mixing and mass transfer: In the fermenter, the injection of compressed air can also promote the mixing and mass transfer processes between different phases, including the contact between liquid and solid, the transfer of dissolved oxygen, and the uptake of nutrients.

In general, compressed air is used to meet the oxygen requirements of the microorganisms during fermentation, to achieve uniform mixing and agitation of the fermentation broth, to facilitate gas exchange, and to maintain temperature and pressure equilibrium within the fermentor. The combined effect of these factors helps to increase fermentation efficiency, improve product quality and reduce costs.