Integrated CO2 capture and dynamic catalysis for CO2 recycling in a microbrewery

In this study, we used fermentation off-gases from a brewery for integrated CO 2 capture and utilisation in order to produce CH 4 with a dual-function material (DFM) containing NiRu as catalyst and dispersed CaO as adsorbent. CH 4 was produced from captured CO 2 via 2 pathways (fast and slow), proceeding through formyl intermediates according to the operando DRIFTS-MS results. The NiRuCa DFM showed a stable CH 4 capacity over 8 cycles (105 μmol/g DFM ) with fermentation off-gases being used as a CO 2 capture feed. H 2 O and O 2 , which were present in small amounts in the emissions feed, resulted in the passivation of Ni in the form of a NiO layer and hence, the DFM did not undergo excessive oxidation and deactivation. This work constitutes a first in terms of validating the use of DFMs with real industrial emissions, and it directly correlates the DFM activity performance with its reaction mechanism and intermediate species. • The operation of a DFM is demonstrated using real CO 2 emissions from a microbrewery. • Operando DRIFTS shows that CH 4 is produced via a fast and a slow reaction pathway. • During operation a passivating NiO layer forms and protects the DFM from excessive oxidation.