Reactor concepts for bioelectrochemical syntheses and energy conversion

• Bioelectrochemical systems (BESs) offer great versatility in their fields of application.
• Recent advances in electrode materials and separators stimulate BES research.
• Electrode and reactor design is a key factor for optimizing BES output.
• Industrial implementation of BESs is still a major challenge.

In bioelectrochemical systems (BESs) at least one electrode reaction is catalyzed by microorganisms or isolated enzymes. One of the existing challenges for BESs is shifting the technology towards industrial use and engineering reactor systems at adequate scales. Due to the fact that most BESs are usually deployed in the production of large-volume but low-value products (e.g., energy, fuels, and bulk chemicals), investment and operating costs must be minimized. Recent advances in reactor concepts for different BESs, in particular biofuel cells and electrosynthesis, are summarized in this review including electrode development and first applications on a technical scale. A better understanding of the impact of reactor components on the performance of the reaction system is an important step towards commercialization of BESs.