Accelerated carbonation is a process that allows to permanently store CO₂ emitted from point sources in a solid form by reaction with minerals or alkaline industrial residues. The activities regarding carbonation of industrial residues are ongoing since 2006 and have allowed to evaluate the feasibility of the process for different types of materials such as steel slag (EAF, AOD and BOF slag) as well as fly ash (APC residues) and bottom ash (BA) from waste incineration. Specifically, our research group has developed a wet route carbonation process applying optimal liquid to solid ratios comprised between 0.2 and 0.4 l/kg. This reaction route allows to avoid the problems related to the disposal of wastewater and to operate efficiently at rather mild operating conditions (T=30-50 °C and PCO₂ < 1 atm). In addition, the treatment has generally shown to exert a positive effect on the environmental properties of the residues, with a significant reduction of the leachate concentrations of several inorganic contaminants with respect to the untreated materials. Current investigations regard the scale-up of the process adopting a granulation reactor.

Collaborations

ETH (Switzerland); University of Rome "La Sapienza".