Preparation, Characterization and Experimental Investigation of the Separation Performance of a Novel CaO-based CO2 Sorbent for Direct Air Capture

The capture of CO2 from air via direct air capture (DAC) is a promising way to reduce the carbon dioxide concentration in the atmosphere. The carbonation of calcium-based adsorbents using ambient conditions is particularly interesting for DAC due to its high theoretical CO2 uptake capacity and its low cost. In this paper, a new preparation method of synthetic calcium oxide-based pellets for a DAC process was investigated. Their CO2 capture performance was studied experimentally in a fixed-bed column and characterization was performed via Brunauer-Emmett-Teller (BET) analysis, mercury porosimetry, X-ray diffraction, and scanning electron microscopy. Higher heating rates during the precursor calcination process and higher relative humidities during the carbonation process were found to lead to higher CO2 capture efficiencies. All prepared pellets showed good mechanical stability.

Automated summary

This study investigated a new preparation method of synthetic calcium oxide-based pellets for DAC process. Their CO2 capture performance was tested experimentally in a fixed-bed column and characterized by BET analysis, mercury porosimetry, X-ray diffraction, and scanning electron microscopy. It was found that higher heating rates during the precursor calcination process and higher relative humidities during the carbonation process led to higher CO2 capture efficiencies. All prepared pellets exhibited good mechanical stability.