RECYCLING OF WASTE CONCRETE IN THE SYNTHESIS OF SOLID ADSORBENTS

Waste concrete generated from building projects was used to prepare a solid adsorbent using the alkali fusion hydrothermal synthesis method, aiming to reduce the cost of the CO 2 capture.The microstructure of the adsorbent materials was analysed using characterisation techniques, including Scanning electron microscopy (SEM), FT-IR spectroscopy, and X-ray diffraction.The results indicate that the synthesised adsorbent has a crystalline structure.The maximum CO 2 adsorption capacity of the synthesised adsorbent reaches up to 2.12 mmolg -1 at 303 K.The results indicated that the synthesised adsorbent exhibits a significantly high CO 2 adsorption capacity and CO 2 /N 2 selectivity.The life cycle assessment (LCA) of the adsorbent synthesis process revealed a minimal environmental impact on the greenhouse effect and water pollution, measured at 6.15 kg CO 2 eq and 2.76 kg 14-DB eq, respectively.The results suggest that utilising waste concrete to prepare a CO 2 adsorbent is feasible, offering a new environmentally friendly approach for waste concrete resource utilisation.