A method for capturing and sequestering carbon dioxide (CO.sub.2) includes receiving and performing an electrochemical process on the input liquid including water and a salt to produce at least one hydroxide-rich stream, and then capturing CO.sub.2 from air using the hydroxide-rich stream and a passive air capture system, thereby producing a liquid carbonate solution containing air-captured CO.sub.2. Optional steps include disposing of the liquid carbonate solution, precipitating air-captured CO.sub.2 from the liquid carbonate solution as solid carbonate and/or a slurry of carbonate, and mixing the liquid carbonate solution with a hydrogen-rich stream produced by the electrochemical process to generate gaseous CO.sub.2. Various integrations and synergies among CO.sub.2 capture, renewable energy, water desalination, and metal and mineral extraction are provided.

A two-stage electrodialysis system and a method for recovering waste CO.sub.2-lean amine solvent are provided. The system includes an amine solution pretreatment filtering system, a C-A homogeneous membrane electrodialysis device, a BP-A bipolar membrane electrodialysis system, and a CO.sub.2 recovery and capture system. The C-A homogeneous membrane electrodialysis system includes a material chamber, a C-A homogeneous membrane electrodialysis device, a concentrated HSSs waste solution chamber, an electrode solution chamber, and corresponding pipelines and peristaltic pumps. The BP-A bipolar membrane electrodialysis system includes a secondary feed chamber, a BP-A bipolar membrane electrodialysis device, an acid liquor chamber, an electrode solution chamber, and corresponding pipelines and peristaltic pumps. The waste CO.sub.2-lean amine solvent enters the material chamber after passing through the amine solution pretreatment filtering system. The concentrated HSSs waste solution chamber is connected to the secondary feed chamber by a buffer tank.

A method of removing acid gases from a gaseous stream is provided. The acid gases may include carbon dioxide, hydrogen sulfide and/or sulfur dioxide, by example. Embodiments of the method include mixing an amine-terminated branched polymer solvent with the gaseous stream, resulting in the substantial absorption of at least some of the acid gases. The solvent is an amine-terminated branched PEG, such as by example amine-terminated glycerol ethoxylate, amine-terminated trimethylolpropane ethoxylate, and/or amine-terminated pentaerithritol ethoxylate. Embodiments of the present inventive methods further include regenerating the solvent using electrolysis.

A capture device for capturing a target gas from a gas flow is disclosed that can be continuously used without requiring consumption of target gas binding salts. To this end, the device is arranged to generate separate acidic and alkaline streams of fluid by electrolyzing water, binding the target gas to the hydroxide ions in the alkaline fluid stream or the hydronium ions in the acidic stream, and recombining the generated streams to release the bound target gas and regenerating part of the electrolyzed water for further electrolysis. Such a capture device may for instance be used in a gas purification system, e.g. an air purification system for controlling target gas levels in a confined space such as a vehicle cabin, domestic dwelling or office space, a target gas generation system or a target gas enrichment system, e.g. for creating target gas-rich air for horticultural purposes. A method for capturing target gas from a gas flow and optionally utilizing the captured target gas is also disclosed.

The present disclosure relates to power plants. The teachings thereof may be embodied in power plants which extract and store carbon dioxide from flue gas generated in the power plant, and in methods for operating a power plant of this kind. For example, a method for operating a power plant may include: generating electrical energy from a combustion process, extracting carbon dioxide from a flue gas generated during the combustion process; storing the extracted carbon dioxide; acquiring current electricity price data; comparing the current electricity price data with an electricity price threshold; and if the electricity price falls below the electricity price threshold, operating an electrolysis device to convert stored carbon dioxide into other substances.

An apparatus and process are provided for electricity production and high-efficiency trapping of carbon dioxide, using carbon dioxide within combustion exhaust gas and converging technologies associated with a carbon dioxide absorption tower and a generating device using ions which uses a difference in concentration of salinity between seawater and freshwater. It is expected that enhanced electrical energy production efficiency, an effect of reducing costs for the operation of a carbon dioxide trapping process, and electricity production from carbon dioxide, which is a greenhouse gas, can be simultaneously achieved by increasing the difference in concentration using an absorbent for absorbing carbon dioxide.

A method of removing carbon dioxide from an atmosphere and generating hydrogen includes capturing carbon dioxide from the atmosphere in an alkaline capture solution, sending the alkaline capture solution to a series of electrolyzers in a CO.sub.2-rich path, wherein each electrolyzer cell raises the acidity of the input CO.sub.2-rich solution to produce an acidified CO.sub.2-rich solution, removing carbon dioxide from the acidified CO.sub.2-rich solution at a carbon dioxide removal unit operation to produce a CO.sub.2-poor solution, sending the CO.sub.2-poor solution to the series of electrolyzers in a return path, wherein each electrolyzer raises the alkalinity of the return CO.sub.2-poor solution to produce a basified CO.sub.2-poor solution, wherein a difference in pH between the CO.sub.2-rich solution and the CO.sub.2-poor solution within each electrolyzer is less than 3, and returning the basified CO.sub.2-poor solution to the carbon dioxide capture unit operation.

A CO.sub.2 capture and sequestration system. The system includes a reduction cell for separating a solvent-based carrier having an anode generating oxygen and a cathode generating hydrogen from the solvent-based carrier. In addition, the system includes a power supply for providing electrical power to the anode and the cathode. An electrolysis process occurs where oxygen and hydrogen are produced. The anode and the cathode include a plurality of geometrical constructs to increase an active surface area of the anode and cathode to increase an efficiency of the electrolysis process. The geometrical constructs may include vias and pillars.

An apparatus for removing an acid gas from a feed gas stream includes an absorber and an electrochemical regenerator. The absorber is adapted for separating the acid gas from the feed gas feed stream using a lean carbon capture solvent. The electrochemical regenerator is connected to the absorber and adapted for (a) regenerating the carbon capture solvent and (b) generating hydrogen gas. A method for removing acid gas from a feed gas stream includes steps of separating, delivering, releasing, generating and returning.

A synthetic fuel production system and related techniques are disclosed. In accordance with some embodiments, the disclosed system may be configured to produce a liquid fuel using carbon dioxide extracted from the air and hydrogen generated from aqueous solutions by electrochemical means (e.g., water electrolysis). In production of the fuel, the disclosed system may be configured, in accordance with some embodiments, to react the carbon dioxide and hydrogen, for example, to form methanol. The disclosed system also may be configured, in accordance with some embodiments, to utilize one or more subsequent reaction steps to produce a given targeted set of hydrocarbons and partially oxidized hydrocarbons. For example, the disclosed system may be used to produce any one (or combination) of: ethanol; dimethyl ether; formic acid; formaldehyde; alkanes of various chain length; olefines; aliphatic and aromatic carbon compounds; and mixtures thereof, such as gasoline fuels, diesel fuels, and jet fuels.