Treatment of Industrial Alkaline Solid Wastes Using Carbon Dioxide

© 2020, Springer Nature Switzerland AG. Carbon dioxide capture and storage (CCS) is an effective method of reducing CO2 emissions into the atmosphere. In this study, improved mineral carbonation is evaluated as a potential for CCS, where CO2 is sequestered in a permanent stable carbonated form. Raw materials were selected from the UAE industrial residues like steel-making, cement and acetylene production because they have calcium-rich content as calcium oxide and/or calcium silicate, which have the potential to store CO2 in the form of permanently stable carbonate minerals. The solid particles were pre-treated, then subjected to direct gas–solid carbonation reaction. Gas analyzer was installed at the output stream of the testing unit to measure the concentration of unreacted CO2 consequently, and calculate CO2 captured by the difference between the initial and final concentration. The carbonated products were characterized using pH, conductivity, TDS, thermal gravimetric analysis (TGA) and scanning electron microscope (SEM) to determine the overall sequestration capacity and efficiency of these waste materials for CCS. Based on the total calcium content, the calculated sequestration of CO2 was: 0.27 kg CO2/kg-ladle furnace (LF) slag, 0.72 kg CO2/kg cement kiln dust (CKD) and 0.58 kg CO2/kg carbide lime waste (CLW)