Amino acid salts for integrated CO2 capture and mineral carbonation of BOF slag

Negative emissions technologies are critical for mitigating rising CO 2 emissions. This study evaluates three amino acid salts – potassium glycinate, potassium sarcosinate, and potassium lysinate – for enhancing mineral carbonation of basic oxygen furnace (BOF) slag. Monoethanolamine served as a benchmark. Carbonation experiments were conducted at 30–80 °C and 0.1–2 M concentrations. Amino acid salts improved carbonation conversion by up to 60% at 30 °C compared to conventional aqueous carbonation. MEA achieved the highest conversion of 85.2% of the theoretical maximal uptake at 80 °C – corresponding to an absolute uptake of 0.36 g CO 2 /g slag. XRD analysis confirmed stabilization of vaterite and aragonite phases. These findings demonstrate the potential of amino acid salt-assisted BOF slag carbonation as an integrated approach for CO 2 capture and utilization. • Enhanced BOF slag mineral carbonation was achieved through use of amino acid salts as CO 2 absorption and dissolution promoters. • Investigated additives led to a significant increase in overall carbonation conversion compared to conventional aqueous carbonation. • Enhanced carbonation was attributed to dual role of amino acid salts: pH buffering and enhanced mineral dissolution. • Amino acid salts were demonstrated to have comparable solution CO 2 absorption as conventional amine-based absorbents such as MEA.