Dan A. Plattenberger

Cement is the world’s most widely consumed man-made material and it contributes between 5% and 10% of the total annual anthropogenic CO2 emissions. Here, we report on a new method for producing crystalline calcium silicate hydrate (CCSH) phases with low lifecycle carbon emissions. The materials were made by curing silicate feedstocks, principally pseudowollastonite (CaSiO3), under elevated partial pressures of CO2 in buffered aqueous solutions.

Efforts to develop safe and effective next-generation energy and carbon-storage technologies in the subsurface require novel means to control undesired fluid migration. Here we demonstrate that the carbonation of calcium silicates can produce reaction products that dramatically reduce the permeability of porous media and that are stable.

The reaction of CO with calcium silicates creates precipitates that can impact fluid flow in subsurface applications such as geologic CO storage and geothermal energy. These reactions nominally produce calcium carbonate (CaCO ) and amorphous silica (SiO ). Here we report evidence that the crystal structure of the parent silicate determines the way in which it reacts with CO and the resulting structures of the reaction products.