Current direct air capture (DAC) approaches require a significant amount of energy for heating CO2-sorbed materials for regeneration and for compressing CO2 for transportation purposes. Rationally designing materials offering both capture and conversion functionalities could enable more energy and cost-efficient DAC and conversion. We have developed a single sorbent-catalytic (non-noble metal) material for the Integrated Direct Air Capture and CATalytic (iDAC-CAT) conversion of captured CO2 into value-added products. Solid sorbents are integrated with catalytic components to first capture CO2 from air. Subsequently, captured CO2, with renewable H2 co-feed is converted into olefins and paraffins. To the best of our knowledge, this is the first proof-of-concept demonstration for production of C2 products such as olefins from captured CO2. Among the different sorbent-catalytic materials studied, Fe/K2CO3/Al2O3 showed the best performance for integrated CO2 capture and conversion to C2 products. CO2 capture capacity of 8.2 wt% was achieved under optimized capture conditions at 25 °C, and a conversion of >70% to paraffins and olefins was achieved at 320–400 °C. The hydrogenation of captured CO2 was facilitated by the in situ formation of Fe3O4 and Fe5C2 species. The proximity between K and Fe was identified to be critical for producing C2 products from the captured CO2. The preliminary technoeconomic and life-cycle assessments suggest that the cost of the DAC can be considerably decreased by adopting the suggested iDAC-CAT technology, while renewable olefins could potentially be produced with negative greenhouse gases emissions.
This article is Open Access
Please wait while we load your content…
Something went wrong. Try again?