Amino acid promoted single-step carbon dioxide capture and mineralization integrated with polymer-mediated crystallization of carbonates.

Integrated CO 2 capture and mineralization is a promising technology for cutting CO 2 emissions and associated environmental impacts. Two major challenges in CO 2 mineralization in aqueous media are (1) the lack of green and energy-efficient processes and (2) limited applications of the produced carbonates. Here, we present a very efficient, environmentally friendly, and convenient integrated CO 2 capture and mineralization method to produce functional calcium carbonate (CaCO 3) particles. We use a gas diffuser reaction setup to bubble CO 2 in liquid media containing reagents such as amino acid as CO 2 absorption promotor, water-soluble polymers as crystal growth modifiers, and Ca2+ ions. Different concentrations of amino acid L-arginine with a fixed CO 2 bubbling rate were investigated for Ca2+ conversion. At the optimized conditions, more than 90% Ca2+ was converted to CaCO 3 within 5 min of CO 2 bubbling at a nominal rate. Additionally, functional carbonates that could be used as dye, heavy metals adsorbents, and functional composite fillers are produced using crystal growth modifiers. The method is simple, efficient, eco-friendly, and could be used for CO 2 /Ca2+-rich industrial waste valorization. [Display omitted] • Arginine is highly efficient in capturing CO 2 in liquid media and subsequent desorption via mineralization. • Simultaneous CO 2 capture and mineralization are performed under ambient conditions. • More than 90% Ca2+ is converted to CaCO 3 within 5 min of CO 2 bubbling. • Biomimetic polymer-mediated crystallization produces functional CaCO 3. • CO 2 absorption promoter arginine can be recovered and reused several times. [ABSTRACT FROM AUTHOR]