A carbon dioxide reduction system includes: an absorption tower configured to bring a source gas containing carbon dioxide into contact with an absorption liquid composed of an aqueous solution containing at least one amine compound so that the carbon dioxide is absorbed in the absorption liquid; an electrolysis apparatus for electrolyzing the carbon dioxide absorbed in the absorption liquid in the absorption tower; and a circulation line for circulating the absorption liquid between the absorption tower and the electrolysis apparatus.

There is provided a process and a system for producing CO and H.sub.2 (syngas) from a CO.sub.2-containing gas. The process includes a step of contacting a CO.sub.2-containing gas with an aqueous absorption solution to produce a bicarbonate loaded stream and a CO.sub.2-depleted gas, followed by a step of subjecting the bicarbonate loaded stream to an electrochemical conversion to generate a gaseous stream including CO and H.sub.2. The system includes an absorption unit wherein the CO.sub.2-containing gas is contacted with the absorption solution to produce the bicarbonate loaded stream and the CO.sub.2-depleted gas and a conversion unit including an electrolytic cell for electrochemically converting bicarbonate ions in the bicarbonate loaded stream into the gaseous stream including CO and H.sub.2 and a bicarbonate depleted stream. In some embodiments, an enzyme such as a carbonic anhydrase can be used to catalyze the conversion of the CO.sub.2-containing gas into the bicarbonate loaded stream.

A system has an alkaline capture stream as an input, an alkaline depleted stream as an output, a carbon dioxide removal unit operation having a return stream as an output, and a series of electrolyzers, each electrolyzer to receive a CO.sub.2-rich input stream and produce an acidified output stream that is more acidic than the CO.sub.2-rich input stream, and to receive a return stream and produce a basified output stream that is more alkaline than the input return stream. A method of removing carbon dioxide from an atmosphere and generating hydrogen includes capturing carbon dioxide from an atmosphere in an alkaline capture solution, sending the alkaline solution as a CO.sub.2-rich input solution to a series of electrolyzers in a CO.sub.2-rich path, removing carbon dioxide from the acidified CO.sub.2-rich solution at a removal unit to produce a CO.sub.2-poor solution, sending the CO.sub.2-poor solution to the series of electrolyzers in a return path, and returning the return solution to the alkaline capture stream. An electrolyzer is also discussed.

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.

The present disclosure provides systems and methods useful in capture of one more moieties (e.g., carbon dioxide) from a gas stream (i.e., direct air capture). In various embodiments, the systems and methods can utilize at least a scrubbing unit, a regeneration unit, and an electrolysis unit whereby an alkali solution can be used to strip the moiety (e.g., carbon dioxide) from the gas stream, the removed moiety can be regenerated and optionally purified for capture or other use, and a formed salt can be subjected to electrolysis to recycle the alkali solution back to the scrubber for re-use with simultaneous production of one or more further chemicals.

The invention relates to a method for purifying a carrier gas which comprises oxygenated impurities in a first oxidation degree, the purification method comprising the circulation, advantageously uninterrupted, of the carrier gas through and along a direction XX of a filter, the filter being made of an oxygen scavenger material which has a redox potential E, and of which a first portion is in a reduced redox state and within which the oxygenated impurities are scavenged and/or pass from the first oxidation degree to a second oxidation degree, the method further comprising the application to the filter of a greater electric potential V, as an absolute value, than the redox potential E during a main purification cycle CP.

Techniques for removing sulfur compounds from a sulfur-containing gas stream can include contacting the gas with an absorption solution comprising a metal cation capable of reacting with the sulfur compound to form a metal sulphide precipitate and/or a metal mercaptide precipitate. In addition, the treatment can include controlling a concentration of the precipitates below a threshold to maintain rheological properties; subjecting the precipitate-enriched solution to vitalization; subjecting the precipitate-enriched solution to regeneration including oxidation; and/or other features to enhance the sulfur removal operations.

A scrubber, an exhaust gas purification system comprising the scrubber, and an air purification method. The treatment water of the scrubber is plasma electrolytic water. The plasma electrolytic water is obtained after water is electrolyzed. The process of electrolysis is carried out in an electromagnetic water treatment device. The electromagnetic water treatment device comprises a cation exchange film, a water flow passage, at least one positive pole panel, at least one negative pole panel, and a magnetic device.

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 removal unit 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.

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.