Potential key strategies for the management of anthropogenic CO2 emissions include mineral carbonation and storage in oil wells and in the oceans. In Europe, a large-scale demonstration of carbon capture and storage (CCS) has recently been given the go-ahead, and the application of mineral carbonation technology (MCT) to serpentine and olive-type minerals. Although less controversial in its approach, MCT involves intensive pre-treatment of the mineral feedstock, and a consequent high sequestration cost USD100-120/tonne CO2 treated.
Mineralisation by carbonation is reliant upon the long-term storage of CO2 in thermodynamically stable and environmentally benign carbonate-based reaction products that are persistent over geological-timescales. The use of solid industrial process wastes for storing carbon (via waste carbonation technology, WCT) may provide a shorter-term gain, as the industrialisation of CO2 mitigation technologies takes place.
With WCT, CO2 is reacted with alkaline waste residues, to both risk-manage a high pH, and utilise waste CO2 gas, can be used as a pre-treatment prior to landfilling, facilitate valorisation and production of new materials.
The present work examines the current status of waste carbonation and investigates the utilisation of seven ‘common’ alkaline industrial residues showing that they have potential to sequestrate 1Gtonne of CO2 worldwide. The projected average cost of USD38-95/tonne of CO2, is competitive with landfill and projected carbon taxes. If WCT is more widely commercially developed an option for the management of significant amounts of carbon could become more quickly established
