Geocatalysts and their application to control co² capture processes, economically and with environmental benefits

The application of geocatalysts in controlling CO2 capture processes in situ as well as in a reaction vessel, chamber or tower is described. More specifically, a process for controlling the reaction of a CO2-containing gas stream with one or more starting materials selected from waste building material, mineral, rock, sand, amorphous material or combinations thereof is disclosed; wherein said starting material comprises Si and/or Al, and one or more divalent cation(s), water, and one or more organic compound(s) to control the reaction; thereby providing a product comprising: at least one carbonate mineral and preferably colloidal silica.