Model based optimization and process control of gas fermentation with the example of methane as a substrate

Biotechnological processes are commonly used to convert cheap and widely available raw materials such as sugars into more valuable components such as polymers, fuels, or protein. In order to maintain high productivity and stable operation of the process, a critical component in modern bioprocesses is the optimization and control of the process. Optimization thereby refers to the a priori choice of operating conditions for maximal productivity, whereas control refers to the online measurement and regulation of the process to maintain the desired conditions despite disturbances. This project focusses on optimization and control of bioprocesses with a gas as carbon source. In particular, the case of methane as substrate is considered, which is available in high quantity from waste remediation and other sources, and currently is mostly used as a gas energy carrier. To expand on methane utilization, biological processes that transform methane into liquid fuels or polymers are currently being developed. Gas fermentation processes are generally more challenging to optimize and control compared to fermentations with classical carbon sources, because the gas needs to be dissolved efficiently into the growth medium. Also, a flammable gas such as methane is a potential security hazard, requiring tighter control of the process conditions. To achieve this, the project develops advanced models and associated control methods for gas fermenations with the example of methane as a substrate.