Enhanced carbon dioxide capture performance of natural mineral vermiculite‐derived lithium silicate with Na doping

Abstract

Natural clay mineral-derived functional materials have attracted considerable attention worldwide. Herein, natural mineral vermiculite (VMT)-derived lithium silicate (VMT-based Li 4 SiO 4 ) materials with different molar ratios of Na to Si were prepared for the high-temperature CO 2 capture. Among developed adsorbents, the VMT-Li 4 SiO 4 -2Na materials displayed superior CO 2 adsorption ability with 0.28 g/g adsorbent adsorption rate after 5 min and 33.67 wt% capture capacity at 650°C. The experimental investigations uncovered the presence of Li 3 NaSiO 4 or/and eutectic Li 2 CO 3 -Na 2 CO 3 molten salt resulting from the introduction of Na 2 CO 3 , which resulted in higher CO 2 uptake. Furthermore, the cyclic carbonation-decarbonation experiment of VMT-Li 4 SiO 4 -2Na showed better stability when the O 2 was used to perform the decarbonation step. We believe that the Na modified-VMT-based Li 4 SiO 4 adsorbent shows potential for practical applications in peak carbon dioxide emissions and carbon neutralization.