Accelerated CO2 capture with controllable mineralisation via reactive bubble formation

• This work showed the presence of a thicker foam layer at a given bubble size increased CO 2 removal efficiency. • Produced predominantly vaterite-phase CaCO 3 through mineralisation, indicating strong potential for industrial applications. • Glycol-based promoters are effective in small amounts, have low toxicity, and are readily biodegradable, making them environmentally friendly and sustainable for CO 2 capture. Carbon Capture and Utilisation (CCU) is crucial for mitigating greenhouse gas emissions from coal-fired power plants. This study presents a bubble reactor system using sodium carbonate (Na 2 CO 3 ) and frothing reagents to improve both efficiency and sustainability. Various glycol-based polymers, along with an alcohol-based surfactant widely used in the mining and minerals industry, were evaluated for their effects on carbon dioxide (CO 2 ) bubble size and removal efficiency. The results demonstrate that the frothing reagents not only reduced bubble size but also increased foam layer thickness, significantly improving CO 2 removal. The thicker foam layer associated with the glycol-type polymers generates a larger interfacial area and longer gas residence time, accounting for the differences in CO 2 removal efficiency. Furthermore, after removing CO 2 , the captured CO 2 was mineralised into calcium carbonate (CaCO 3 ). Notably, the calcium carbonate existed predominantly in the form of vaterite and the abundance and morphology of vaterite changed with adding one of the polymers into the CO 2 -loaded Na 2 CO 3 solution. This paper underscores the potential for scalable, sustainable CCU, along with the formation of valuable by-products.