Formic acid (FA) is a promising reservoir for hydrogen storage and distribution. Its dehydrogenation releases CO2 as a by-product, which limits its practical application. A proof of concept for a bio-catalytic system that simultaneously combines the dehydrogenation of formic acid for H2, in-situ capture of CO2 and its re-hydrogenation to reform formic acid is demonstrated. Enzymatic reactions catalyzed by carbonic anhydrase (CA) and formate dehydrogenase (FDH) under ambient condition are applied for in-situ CO2 capture and re-hydrogenation, respectively, to develop a sustainable system. Continuous production of FA from stripped CO2 was achieved at a rate of 40% using FDH combined with sustainable co-factor regeneration achieved by electrochemistry. In this study, the complete cycle of FA dehydrogenation, CO2 capture, and re-hydrogenation of CO2 to FA has been demonstrated in a single system. The proposed bio-catalytic system has the potential to reduce emissions of CO2 during H2 production from FA by effectively using it to recycle FA for continuous energy supply.
H2 production by steam reforming with in situ CO2 capture of biomass-derived bio-oil
