Optimization of membrane processes in white biotechnology

White biotechnology for the production of fine chemicals will substitute some chemistry based on petrol and gas in the near future. A standard process for this technology is fermentation. The downstream treatment with membranes is an essential and cost-intensive part of the processing. For downstream processing plate and frame systems are very common due to their robustness and their open channel design. Another essential part of the process is the optimization of membrane fouling. A process for a protease production was used as a reference. The antifoam agent that was used had a strong fouling tendency. It could be shown that a high priced polyamide-imide/polyethersufone membrane could be substituted with a standard, lower priced polyethersufone membrane by optimizing the temperature and antifoam agents.

Downstream treatment is an essential step in the fermentation process. Different module configurations and pre-treatments are common in this production step. The choice of the process depends on the sensitivity of the product and the viscosity. The optimization of a process also includes the adjusting of the membrane to the fermentation conditions. Although a hydrophilic membrane showed the best fouling resistance the changes of the fouling layer also changed the retention of the membrane and decreased the economic benefit. Changing the antifoam agent could decrease the fouling tendency and lead to a stable process. Therefore, optimization of the membrane process goes hand in hand with the optimization of the fermentation conditions and the analysis of the product properties.