The present invention relates to a method and an apparatus of preparing a reduction product of carbon dioxide by electrochemically reducing carbon dioxide. The present invention can prepare, in an energy-efficient manner, a reduction product of high-concentration carbon dioxide with high Faraday efficiency as in a liquid reduction reaction by producing the reduction product of carbon dioxide by supplying water or an electrolytic solution to an anode region; supplying humidified carbon dioxide gas having a second temperature higher than a first temperature to a cathode region within an electrochemical cell having the first temperature so as to supply the carbon dioxide gas which has been humidified to be in a condition where the relative humidity is greater than 100%, while applying a voltage between the anode region and the cathode region so as to generate hydrogen ions (H.sup.+) in the anode region; and transporting the hydrogen ions to the cathode region through the electrolyte membrane, thereby electrochemically reducing the carbon dioxide gas.

A method of capturing a target species from a gas comprises the steps of: contacting a gas containing a target species with a first absorbent solution comprising a capture species; dissolving the target species in the first absorbent solution to form a target anion; electrochemically separating the target anion from the first absorbent solution by contacting the first absorbent solution with one or more ion-exchange membranes, and transferring the target anion through an ion-exchange membrane into a second absorbent solution; and releasing at least some of the target species from the second absorbent solution. The one or more ion-exchange membranes are not permeable to the capture species, so the capture species does not pass through the one or more ion-exchange membranes. An apparatus for capturing a target species from a gas is also provided.

A system and method for the reduction of NOx and CO contaminants using an ion-exchange resin media having lower-valency ions of the transitional metal elements, such as ferrous ions, cuprous ions and/or manganese ions, such that gases containing NOx and/or CO contaminants may be passed over the media so that the contaminants are absorbed by the lower-valency ions of the transitional metal elements, the media configured so that it can be regenerated to remove the NOx and/or CO contaminants. Regeneration includes exposing the media to a heated stream of hydrogen gas or exposing the media to hydrogen ions in an electrochemical cell.

In an embodiment, a method for recovering carbon dioxide comprises introducing a carbon dioxide rich stream to a scrubber comprising a metal hydroxide and allowing the carbon dioxide to react with the metal hydroxide to form a metal carbonate; directing a metal carbonate stream from the scrubber to an electrochemical concentrator and applying a potential to the electrochemical concentrator to form a metal hydroxide stream and a separated carbon dioxide stream; directing the metal hydroxide stream comprising a recovered metal hydroxide and hydrogen to an electrochemical separator and applying a potential to the electrochemical separator to separate the hydrogen forming a hydrogen recycle stream from the recovered metal hydroxide forming a metal hydroxide recycle stream; and directing the separated carbon dioxide stream to a gas liquid separator and separating the separated carbon dioxide stream into a recycled water stream and a concentrated carbon dioxide stream.

A system and method for the reduction of NOx and CO contaminants using an ion-exchange resin media having lower-valency ions of the transitional metal elements, such as ferrous ions, cuprous ions and/or manganese ions, such that gases containing NOx and/or CO contaminants may be passed over the media so that the contaminants are absorbed by the lower-valency ions of the transitional metal elements, the media configured so that it can be regenerated to remove the NOx and/or CO contaminants. Regeneration includes exposing the media to a heated stream of hydrogen gas or exposing the media to hydrogen ions in an electrochemical cell.

A carbon dioxide recovery system capable of effectively suppressing deterioration of the carbon dioxide adsorption performance of an electrochemical cell is provided. The carbon dioxide recovery system includes a control unit which is configured to perform as an information acquisition unit. The information acquisition unit acquires information about a substance contained in the atmosphere that may adhere to an electrochemical cell. Then, the control device is configured to switch between execution and non-execution of at least carbon dioxide recovery control based on the information acquired by the information acquisition unit.

A composite includes a nonwoven carbon nanotube mat and an electroactive species disposed on the nonwoven carbon nanotube mat, wherein the electroactive species is capable of bonding with a target gas when the electroactive species is in a reduced state and releasing the target gas when the electroactive species is in an oxidized state. Electrode assemblies, electro-chemical cells, and gas separation systems including the composite are also described herein.

The present invention generally relates to methods and systems for carrying out a pH-influenced chemical and/or biological reaction. In some embodiments, the pH-influenced reaction involves the conversion of CO.sub.2 to a dissolved species.

Plasma is generated in a gas phase in a processing tub to produce a reforming component, the produced reforming component is dissolved in a liquid and is dispersed in the liquid to produce a reforming liquid, the produced reforming liquid is discharged from the processing tub to be stored in the storage tub, and gas is supplied from a gas supplier into the reforming liquid in the storage tub. The supplied gas has a bubble shape, comes into contact with the reforming liquid stored in the storage tub, and is deodorized.

The invention is directed to a process to prepare elemental sulphur by (i) contacting an aqueous solution comprising bisulphide with oxidised sulphide-oxidising bacteria under anaerobic conditions wherein elemental sulphur is produced and a reduced sulphide-oxidising bacteria is obtained and (ii) wherein the reduced sulphide-oxidising bacteria are oxidised by transfer of electrons to an anode of an electrochemical cell to obtain the oxidised sulphide-oxidising bacteria.