Processes specific to the CRD waste service
Construction, renovation and demolition (CRD) residues pose constant challenges in terms of their recovery. As with any other waste, efficient sorting increases its value. However, this is not enough to guarantee their diversion from landfill; it is also necessary to find interesting and economically viable outlets for them!
The advantage of supercritical CO2
In the supercritical state (32 deg C, 73 bars), CO2 adopts the behaviour of an apolar solvent capable of dissolving very efficiently the oils, fats and other non-polar compounds whose extraction is desired. CO2 can then advantageously replace flammable, explosive and carcinogenic organic solvents commonly used in industry (e.g. hexane, chloroform, toluene). This process was used by the CTTÉI to successfully extract residual bitumen from used asphalt shingles.
A promising process
With bitumen costs ranging from $500 to $800 per tonne, this clean process looks promising for the DRB industry. The results of this project will be presented and discussed by researcher Jean-François Vermette at the Colloque Innovations en valorisation des matières résiduelles tomorrow, October 27 in Sherbrooke. Register in large numbers or contact us to learn more!
