Disclosed is a hybrid system of carbon dioxide compact separation membrane and carbon recycling for an urban power plant for effluent carbon dioxide concentration control, including a blower into which an exhaust gas is input and which distributes the exhaust gas, a photo-culture process unit which receives the exhaust gas from the blower, performs a photo-culture process using microalgae, and discharges a first treatment gas, a mixing tank into which the exhaust gas supplied from the blower and the first treatment gas are input, a separation membrane process unit which receives a second treatment gas mixed in the mixing tank, and separates a third enriched gas from the second treatment gas using a plurality of separation membranes, a mineralization reaction unit which mineralizes carbon dioxide using the third enriched gas separated in the separation membrane process unit and discharges a third treatment gas to the mixing tank, a sensor unit which measures a carbon dioxide concentration discharged from each process using a plurality of sensors, and a control unit which controls operations of the photo-culture process unit, the separation membrane process unit and the mineralization reaction unit according to a carbon dioxide content of the inflow exhaust gas.

Disclosed is a hybrid system of carbon dioxide compact separation membrane and carbon recycling for an urban power plant for effluent carbon dioxide concentration control, including a blower into which an exhaust gas is input and which distributes the exhaust gas, a photo-culture process unit which receives the exhaust gas from the blower, performs a photo-culture process using microalgae, and discharges a first treatment gas, a mixing tank into which the exhaust gas supplied from the blower and the first treatment gas are input, a separation membrane process unit which receives a second treatment gas mixed in the mixing tank, and separates a third enriched gas from the second treatment gas using a plurality of separation membranes, a mineralization reaction unit which mineralizes carbon dioxide using the third enriched gas separated in the separation membrane process unit and discharges a third treatment gas to the mixing tank, a sensor unit which measures a carbon dioxide concentration discharged from each process using a plurality of sensors, and a control unit which controls operations of the photo-culture process unit, the separation membrane process unit and the mineralization reaction unit according to a carbon dioxide content of the inflow exhaust gas.

Aspects of the invention include methods of removing carbon dioxide (CO.sub.2) from a CO.sub.2 containing gas. In some instances, the methods include contacting CO.sub.2 containing gas with a bicarbonate buffered aqueous medium under conditions sufficient to produce a bicarbonate rich product. Where desired, the resultant bicarbonate rich product or a component thereof may then be stored or further processed, e.g., combined with a divalent alkaline earth metal cation, under conditions sufficient to produce a solid carbonate composition. Aspects of the invention further include systems for practicing the methods, as well as products produced by the methods.

Aspects of the invention include methods of removing carbon dioxide (CO.sub.2) from a CO.sub.2 containing gas. In some instances, the methods include contacting CO.sub.2 containing gas with a bicarbonate buffered aqueous medium under conditions sufficient to produce a bicarbonate rich product. Where desired, the resultant bicarbonate rich product or a component thereof may then be stored or further processed, e.g., combined with a divalent alkaline earth metal cation, under conditions sufficient to produce a solid carbonate composition. Aspects of the invention further include systems for practicing the methods, as well as products produced by the methods.

A method includes: (1) using a chelating agent, extracting divalent ions from a brine solution as complexes of the chelating agent and the divalent ions; (2) using a weak acid, regenerating the chelating agent and producing a divalent ion salt solution; and (3) introducing carbon dioxide to the divalent ion salt solution to induce precipitation of the divalent ions as a carbonate salt. Another method includes: (1) combining water with carbon dioxide to produce a carbon dioxide solution; (2) introducing an ion exchanger to the carbon dioxide solution to induce exchange of alkali metal cations included in the ion exchanger with protons included in the carbon dioxide solution and to produce a bicarbonate salt solution of the alkali metal cations; and (3) introducing a brine solution to the bicarbonate salt solution to induce precipitation of divalent ions from the brine solution as a carbonate salt.

A method including reacting, at a jobsite, a total dissolved solids (TDS) water with a gas comprising carbon dioxide (CO.sub.2) in the presence of a proton-removing agent to produce a CO.sub.2-reduced gas and an aqueous product comprising water and a precipitate, wherein the TDS water comprises produced water, wherein the precipitate comprises one or more carbonates, and wherein the CO.sub.2-reduced gas comprises less CO.sub.2 than the gas comprising CO.sub.2; and separating at least a portion of the water from the aqueous product to provide a concentrated slurry of the precipitate and a TDS-reduced water, wherein the TDS-reduced water comprises less TDS than the TDS water.

A method including reacting, at a jobsite, a total dissolved solids (TDS) water with a gas comprising carbon dioxide (CO.sub.2) in the presence of a proton-removing agent to produce a CO.sub.2-reduced gas and an aqueous product comprising water and a precipitate, wherein the TDS water comprises produced water, wherein the precipitate comprises one or more carbonates, and wherein the CO.sub.2-reduced gas comprises less CO.sub.2 than the gas comprising CO.sub.2; and separating at least a portion of the water from the aqueous product to provide a concentrated slurry of the precipitate and a TDS-reduced water, wherein the TDS-reduced water comprises less TDS than the TDS water.

Embodiments of the present disclosure are directed to systems and methods of removing carbon dioxide from a gaseous stream using magnesium hydroxide and then regenerating the magnesium hydroxide. In some embodiments, the systems and methods can further comprise using the waste heat from one or more gas streams to provide some or all of the heat needed to drive the reactions. In some embodiments, magnesium chloride is primarily in the form of magnesium chloride dihydrate and is fed to a decomposition reactor to generate magnesium hydroxychloride, which is in turn fed to a second decomposition reactor to generate magnesium hydroxide.

Embodiments of the present disclosure are directed to systems and methods of removing carbon dioxide from a gaseous stream using magnesium hydroxide and then regenerating the magnesium hydroxide. In some embodiments, the systems and methods can further comprise using the waste heat from one or more gas streams to provide some or all of the heat needed to drive the reactions. In some embodiments, magnesium chloride is primarily in the form of magnesium chloride dihydrate and is fed to a decomposition reactor to generate magnesium hydroxychloride, which is in turn fed to a second decomposition reactor to generate magnesium hydroxide.

Systems and methods for sequestering carbon, evolving hydrogen gas, producing iron oxide as magnetite, and producing magnesium carbonate as magnesite through sequential carbonation and serpentinization/hydration reactions involving processed olivine- and/or pyroxene-rich ores, as typically found in mafic and ultramafic igneous rock. Precious or scarce metals, such nickel, cobalt, chromium, rare earth elements, and others, may be concentrated in the remaining ore to facilitate their recovery from any gangue material.