Abstract: Methods of characterizing and producing compositions with negative ?13C values are provided. Aspects of the invention include characterizing source materials and process products. Aspects of the invention also include compositions that contain carbon with negative ?13C values.

Abstract: Methods are provided for producing a composition comprising carbonates, wherein the methods comprise utilizing waste sources of metal oxides. An aqueous solution of divalent cations, some or all of which are derived from a waste source of metal oxides, may be contacted with CO2 and subjected to precipitation conditions to provide compositions comprising carbonates. In some embodiments, a combustion ash is the waste source of metal oxides for the aqueous solution containing divalent cations. In some embodiments, a combustion ash is used to provide a source of proton-removing agents, divalent cations, silica, metal oxides, or other desired constituents or a combination thereof.

Abstract: Provided are methods for producing carbonate-containing compositions comprising silicon-based material (e.g., pozzolanic material) from a source of carbon dioxide, a divalent cation-containing solution, and a source of proton-removing agents. In such methods, divalent cations of the divalent cation-containing solution are provided by digestion of material comprising metal silicates. Also provided are methods for producing carbonate-containing compositions comprising little or no silicon-based material. In such methods, silicon-based material (e.g., silica, unreacted or undigested silicates, aluminosilicates, etc.) may be separated and processed separately from carbonate-containing compositions. Silicon-based material and carbonate-containing material may be blended at a later stage to produce a pozzolanic material, which may be further processed and blended with, for example, Portland cement.

Abstract: Methods of sequestering carbon dioxide (CO2) are provided. Aspects of the methods include precipitating a storage stable carbon dioxide sequestering product from an alkaline-earth-metal-containing water and then disposing of the product, e.g., by placing the product in a disposal location or using the product as a component of a manufactured composition. Also provided are systems for practicing methods of the invention.

Abstract: The present invention describes a porous polyphosphate ceramic, which comprises a network of interconnected particles or fibers, each of these particles has an amorphous polyphosphate core and an outer dried polyphosphate hydrogel layer. The composition of the hydrogel polyphosphate layer includes an amorphous polyphosphate, water and a multivalent cation. The network is interconnected through connections made in a region of the hydrogel polyphosphate layer between adjacent integrated polyphosphate particles that is later dried. The invention also describes the method of producing the porous polyphosphate ceramic by adding water to polyphosphate particles, partially dissolving the particles, to produce a hydrogel layer, allowing the hydrogel layer between adjacent particles to integrate and drying the integrated particles to produce the porous ceramic.