Abstract
Direct removal of carbon dioxide from atmospheric air has been widely advocated as a key tool in the strive towards zero emissions. One class of technology for direct air capture (DAC) uses aqueous sorbents in air-liquid contactors to extract the CO2. Here we present the first systematic data on enzyme assisted DAC and show that even very low (sub µM) concentrations of carbonic anhydrase (CA) exert a strong acceleration on CO2 absorption. We also found that CA promoted the ability to retain a high capture efficiency as the flow rate was raised and we rationalized these observations based on molecular mechanism of enzyme assisted capture. We interpret that acceleration of carbon capture with CA is more efficient under DAC conditions (short contact times and diluted sources) than during capture from CO2 sources. These attributes may eventually pave the way for DAC in sorbents with low regeneration energies such as carbonate.
Supplementary materials
Title
Supporting Information
Description
Supporting Information contains experimental data on enzyme stability, data analysis, experimental comparison with compressed air, supplementary arguments regarding mechanistic interpretation, air residence time in column calculation, absorption efficiency vs gas flow rate.
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