Design, implementation and assessment of a novel bioreactor for fermentative biohydrogen process development

Hydrogen production using dark fermentation is challenged by a low yield. Factors affecting the yield include the reactor configuration, the microbial community structure and other physico-chemical parameters. This paper reports the implementation and assessment of a novel reactor type. The vessel was made up of a 2-L glass with five ports. Three 3D-printed porous cartridges supported the immobilized microbial cells and served as baffles. Mixing was achieved by rocking the vessel at 180°. All the control set points could be varied, offering the possibility of assessing various control regimes. For biohydrogen production, the implemented reactor showed 58 and 60% reduction in lag time for immobilized and suspended culture respectively, and 35 and 12% increase in peak hydrogen fraction for the immobilized and suspended cells respectively, compared to the flask reactor. These findings highlight the capabilities of this reactor configuration to enhance the productivity and yield of biohydrogen.