A method and system for sequestration of carbon dioxide from atmospheric air is disclosed. The method and system comprise the enabling of atmospheric air (16) to pass into an upper end of an elongate hollow tower (10). An aqueous solution (14) is charged (e.g. via a distributor) so as to mix with the atmospheric air within and adjacent to the tower upper end in a manner such that the air is cooled by evaporative cooling. As a result, the mixture passes downwards as a stream (22) through the hollow tower. The aqueous solution comprises a reagent added thereto that reacts with the carbon dioxide to form a compound in the solution to thereby sequester the carbon dioxide from the atmospheric air. The method and system also comprise generating electricity (32, 33, 35) (e.g. in an apparatus such as a gas turbine) from the downwards stream that is passing through the hollow tower.

A system and method recover process gas from a source volume at a source pressure to a destination volume at an equal or greater pressure. A regulation process receive the process gas from the source volume and steps down the pressure. Each regulation uses one or more stage each using a pressure control valve for pressure step down and a heat exchanger for reheating the process gas thereafter. A gas scrubber receives the process gas from the regulation stages and collecting liquid from the process gas. A compression process receives the process gas from the gas scrubber and steps up the intermediate pressure to a final pressure. The compression can use one or more compression stages, each having a compression cycle for pressure step up and a heat exchanger for cooling the process gas thereafter. A discharge vessel receives the process gas from the compression process and discharges the process gas at the final pressure to the destination volume. The final pressure is equal to or greater than the destination pressure.

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.

A method and apparatus for cleaning a contaminated gas, the method comprising passing the contaminated gas through at least two cleaning stages of rubber material through which water flows, wherein the gas and the water pass cocurrently though the at least two stages of rubber material.

The invention relates to a reactor for cleaning flue gases by a dry or quasi-dry sorption process, comprising a flue gas inlet (1) at the bottom of the reactor, an outlet (2) at the top of the reactor, a dry sorbent injection system (3) with at least one dry sorbent outlet (4) for injecting dry sorbent into the reactor, the at least one dry sorbent outlet (4) being arranged between the flue gas inlet (1) and the outlet (2).

An alkaline aqueous ferric iron salt solution is disclosed. Generally, the alkaline aqueous ferric iron salt solution comprises ferric ions (Fe.sup.3+), potassium ions (K.sup.+), carbonate ions (CO.sub.3.sup.2−), bicarbonate ions (HCO.sub.3.sup.−), hydroxide ions (OH.sup.−), optionally nitrate ions (NO.sub.3.sup.−). Further, a molar ratio of the potassium ions to the ferric ions is generally at least 5.0. The ferric iron is complexed with carbonate, bicarbonate or both to form a water-soluble complex that is anionic in nature and highly soluble in the alkaline aqueous ferric iron salt solution at pH above 8.5, and a pH of the alkaline aqueous ferric iron salt solution is at least 8.5.

A method of scavenging acid sulfide species from an industrial or environmental material, the method comprising contacting the material with: (a) propenal and/or maleimide and/or ethyl-2-chloroacetoacetate; and (b) a base.

A system for oxidizing nitrogen monoxide (NO) contained in exhaust gas injects a liquid oxidizing agent into the exhaust gas and simultaneously removes nitrogen oxides and sulfur oxides from exhaust gas using an organic catalyst. The system includes an absorption tank for storing an absorption solution containing an organic catalyst, the absorption tank communicating with an oxygen supply pipe for supplying oxygen-containing gas to the absorption tank; an absorption tower, extending upward from the absorption tank, through which the exhaust gas flows from an exhaust gas inlet duct to an exhaust gas outlet; a first injection unit to inject the absorption solution into the absorption tower; a second injection unit to inject an oxidizing agent solution into at least one of the inlet duct and the absorption tower; and an oxidizing agent supply unit for supplying the oxidizing agent solution to the second injection unit.

The present invention describes a fluid which is suitable for the decontamination of heat engines which can carry out both, at the same time, the catalytic reduction of oxides of nitrogen (NOx) contained in exhaust gases and assist in the regeneration of the particulate filter (PF). The invention also describes several embodiments of said fluid.

Methods for removing reduced sulfur compounds, such as hydrogen sulfide, from fluids employing a ferric iron salt that exhibits unusually high solubility in aqueous, alkaline solutions and has strong affinity for capture and oxidation of reduced sulfur compounds. Alkaline aqueous ferric iron salt and solutions thereof useful for removing reduced sulfur compounds from fluids and various methods of production of such salts and solutions. In addition, methods of regenerating the alkaline aqueous ferric iron salt solutions after capture of hydrogen sulfide or other reduced sulfur compounds, generally by exposure to oxygen in air. The alkali metal carbonate salt preferably comprises potassium carbonate and/or potassium bicarbonate. The alkaline aqueous ferric iron salt solutions generally comprise ferric ions, potassium ions, carbonate ions, and bicarbonate ions, optionally with one or more organic additives. In addition, aqueous-soluble, ferric iron salts and ferric iron containing solids prepared by removal of aqueous medium from solutions herein.