Transferring bioelectrochemical processes from H-cells to a scalable bubble column reactor

Abstract

In times of energy revolution, bioelectrochemistry is a growing field of research, either for the generation of electrical energy from organic substrates or the use of electrical energy to produce various products. By now, this technology is on the turning point from lab scale to industrial applications. Unfortunately, there is still a lack of well characterized, scalable reactor systems that are capable of hosting different bioelectrochemical processes, linking lab scale research to industrial application. In this paper, we introduce a two-chamber bioelectrochemical bubble-column reactor (one liter working volume), which can be used as microbial fuel cell as well as for microbial electrosynthesis and is especially advantageous for processes with gaseous substrates. It is designed flexible in terms of electrode material and area, membrane material and area, and capable of hosting continuous processes. It is a promising replacement of lab-scale H-cells for wider screening possibilities with regard to industrial applications. We characterized the reactor by giving key values such as kLa and gas hold up, and suggest scale-up parameters. These are, for example, dimensionless numbers like Reynolds and Wagner number and different ratios that should be kept constant during scale-up. Therefore, this paper can be a guideline for the development and scale-up of bioelectrochemical systems.