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.

Injecting CO2 that is diluted within water, into a coal seam, which allows for the sequestering and control of downhole CO2 within connected fractures without damaging the subterranean formation.

A method of purifying air polluted by smoke and fumes, such as from wildfires and other hazard, may deploy a series of fluid filled vessels that act as filters to trap and/or neutralize components that would foul an aqueous suspension of gold nanoparticles that is effective in converting toxic carbon monoxide to carbon dioxide. Non-toxic fluids may be used. As the gold nanoparticles are effective in a basic solution, the solution may contain a visible pH indicator or an apparatus that deploys the method may continuously monitor the pH thereof.

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 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.

A composition for use in brine formation comprising a deliquescent desiccant, urea, and an optional component selected from the group consisting of starch, citric acid, clay, glucose, and a combination thereof. Methods of making and using the composition are provided. The composition may be pressed into tablet form. The composition may be used in a dehumidifying device.

A composition for use in brine formation having a deliquescent desiccant, urea, and an optional component selected from the group consisting of starch, citric acid, clay, glucose, and a combination thereof. Methods of making and using the composition are provided. The composition may be pressed into tablet form. The composition may be used in a dehumidifying device.

Methods of sequestering carbon dioxide (CO.sub.2) are provided. Aspects of the methods include contacting an aqueous capture ammonia with a gaseous source of CO.sub.2 under conditions sufficient to produce an aqueous ammonium carbonate. The aqueous ammonium carbonate is then combined with a cation source under conditions sufficient to produce a solid CO.sub.2 sequestering carbonate and an aqueous ammonium salt. The aqueous capture ammonia is then regenerated from the from the aqueous ammonium salt. Also provided are systems configured for carrying out the methods.

A plurality of carbonation plots are positioned in communication with atmospheric carbon dioxide to facilitate sequestration thereof via ambient weathering. The carbonation plots include a composition rich in metal oxides, which are positioned within the environment, such as on non-arable land, and exposed to the environment to react with carbon dioxide in the air and form metal carbonates. After about one year of exposure, the composition is recollected and calcined to produce a carbon dioxide stream and replenish the metal oxides, which can be redistributed in the carbonation plots to sequester additional carbon dioxide. The systems and methods of the present disclosure enable capture and redistribution of carbon dioxide for industrial-scale uses for very abundant quarry minerals and enable large-scale low-cost carbon capture projects for municipalities or corporations. CO.sub.2 removal from air via these methods and systems have a similar or lower cost than CO.sub.2 removal using DAC with synthetic sorbents or solvents.