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 CO2 capture. The microstructure of the adsorbent materials was analysed using characterisation techniques, including Scanning electron microscopy (SEM), FT-IR spectroscopy, andX-ray diffraction. The results indicate that the synthesised adsorbent has a crystalline structure. The maximum CO2 adsorption capacity of the synthesised adsorbent reaches up to 2.12 mmol center dot g-1 at 303 K. The results indicated that the synthesised adsorbent exhibits a significantly high CO2 adsorption capacity and CO2/N2 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 CO2 eq and 2.76 kg 14-DB eq, respectively. The results suggest that utilising waste concrete to prepare a CO2 adsorbent is feasible, offering a new environmentally friendly approach for waste concrete resource utilisation.