In a preferred embodiment, the invention relates to a process of sequestering carbon dioxide. The process comprises the steps of: (a) reacting a metal silicate with a caustic alkali-metal hydroxide to produce a hydroxide of the metal formerly contained in the silicate; (b) reacting carbon dioxide with at least one of a caustic alkali-metal hydroxide and an alkali-metal silicate to produce at least one of an alkali-metal carbonate and an alkali-metal bicarbonate; and (c) reacting the metal hydroxide product of step (a) with at least one of the alkali-metal carbonate and the alkali-metal bicarbonate produced in step (b) to produce a carbonate of the metal formerly contained in the metal silicate of step (a).

The present invention provides a method for manufacturing a composite carbonate in a semi-dry manner by using combustion ash and, more specifically, provides a method for manufacturing a composite carbonate in a semi-dry manner by using combustion ash, the method comprising a step of adding a small amount of water to combustion ash containing calcium ions in an atmosphere of carbon dioxide. According to the present invention, carbon mineralization is carried out in a semi-dry manner by the manufacturing method, so that the composite carbonate can be efficiently produced. In addition, the composite carbonate can be utilized as a component for a concrete composition.

Systems of producing hydrogen and biochar from biomass assisted by iron and steel slag extract include: a pretreatment system that the reactants, including the biomass, iron-based catalyst and alkaline reagent, are pretreated and fully mixed at specific ratios in the pretreatment system; thermal reactor that the mixed reactants from the pretreatment device are transferred into and fully reacted in the thermal reactor; a solid residue collector that the solid residue is collected by the solid residue collector at the discharge outlet of the thermal reactor after the reacted mixture is separated; a gas collection system that he generated hydrogen-based gas is collected by the gas collection system from the exhaust port of the thermal reactor.

CO.sub.2, and other gases are utilized with mineral feedstock to synthesize products. The synthesized products, as the result of liquid, solid, gas photo-chemical reactions within the advanced bioreactor of the disclosed embodiment, are precipitated raw material for multiple consumer and industrial products. Waste heat, pressure and torque produced from the bioreactor are utilized for generating electricity and/or heat through a combination of energy recovery devices. Energy recovery devices offsets and lower the cost of operating the reactor as the disclosed reactor integrates photolysis via ultra-violet light, as an integral component, of a reactor system, composed also of an active mixer-agitator assembly, pressure and vacuum vessel chamber, heat source, and ports for media ingestion. The disclosed reactor is designed be conducive to transforming gaseous, solid, and liquid feedstock, like carbon dioxide —CO.sub.2, and other feedstocks that are inorganic and/or organic in an aqueous medium, into inorganic and organic products.

According to the present invention, provided is a carbonate- and magnesium-substituted hydroxyapatite having a particle size of 5 nm or more and 60 nm or less, wherein a portion of the calcium atoms in the hydroxyapatite are substituted with magnesium atoms and a portion of phosphate groups are substituted with carbonate groups.

Compositions and methods for oxidizing organic contaminants while sequestering inhibitory forms of carbon. An oxidant capable of producing free radicals oxidizes organic contaminants. A metal oxide, metal hydroxide, or metal peroxide generates a soluble hydroxide concentration of about 1×10.sup.−4 M or greater to convert carbonic acid, bicarbonate ion, methane, elemental carbon, and other organic forms of carbon to carbonate ion. A metal having a carbonate with a lower solubility product constant than its hydroxide precipitates the carbonate ion as a metal carbonate, thereby eliminating soluble carbonate as a radical scavenger. Compositions and methods that additionally minimize metal solubilization and sequester solubilized metals are also disclosed.

Compositions and methods for oxidizing organic contaminants while sequestering inhibitory forms of carbon. An oxidant capable of producing free radicals oxidizes organic contaminants. A metal oxide, metal hydroxide, or metal peroxide generates a soluble hydroxide concentration of about 1×10.sup.−4 M or greater to convert carbonic acid, bicarbonate ion, methane, elemental carbon, and other organic forms of carbon to carbonate ion. A metal having a carbonate with a lower solubility product constant than its hydroxide precipitates the carbonate ion as a metal carbonate, thereby eliminating soluble carbonate as a radical scavenger. Compositions and methods that additionally minimize metal solubilization and sequester solubilized metals are also disclosed.

Methods of producing solid CO.sub.2 sequestering carbonate materials are provided. Aspects of the methods include introducing a divalent cation source into a flowing aqueous liquid (e.g., a bicarbonate rich product containing liquid) under conditions sufficient such that a non-slurry solid phase CO.sub.2 sequestering carbonate material is produced. Also provided are systems configured for carrying out the methods.

Methods of producing solid CO.sub.2 sequestering carbonate materials are provided. Aspects of the methods include introducing a divalent cation source into a flowing aqueous liquid (e.g., a bicarbonate rich product containing liquid) under conditions sufficient such that a non-slurry solid phase CO.sub.2 sequestering carbonate material is produced. Also provided are systems configured for carrying out the methods.

This invention describes a method and apparatus for the capture, storage and release of carbon dioxide for use in the horticulture industry, the method including reduction of a transition metal oxide to form a transition metal and carbon dioxide; carburization or partial carburization of the transition metal to form metal carbide; carbonation of an alkaline metal oxide or alkaline earth metal oxide to form an alkaline metal carbonate or alkaline earth metal carbonate; contacting the metal carbide with air to produce a transition metal oxide and carbon dioxide; and calcining the alkaline metal carbonate or alkaline earth metal carbonate to form carbon dioxide and alkaline metal oxide or alkaline earth metal oxide. Also described is a sorbent material for use in the method and apparatus of the invention.