A process is presented where a feed stream containing a hydrogen sulfide and another feed component is introduced into an absorber that the feed stream flows upward from the bottom of the absorber and contacts a liquid treatment solution, where the liquid treatment solution contains a sulfur dye catalyst. The hydrogen sulfide is absorbed into the liquid treatment solution and converted into sulfide ions. The other feed component is removed from the absorber vessel substantially free of the hydrogen sulfide and a spent treatment solution is also removed from the absorber vessel and fed to an oxidation vessel where it is contacted with an oxygen containing gas causing the sulfide ions to oxidize to thiosulfate and converting the spent sulfur dye catalyst to regenerated sulfur dye catalyst. The thiosulfate is recovered, and the regenerated sulfur dye catalyst can be recycled as part of the liquid treatment solution.

A NO.sub.x and SO.sub.x oxidation with atmospheric oxygen to remove NO.sub.x and SO.sub.x from flue gases. The combined system for catalytic oxidation and wet-scrubbing of NO.sub.x and SO.sub.x from a flue gas and manufacturing fertilizers includes: an air separation unit for separating atmospheric oxygen from air and producing an air stream enriched with atmospheric oxygen, an adsorption and oxidation reactor containing an oxidation catalyst and carrying out the catalytic oxidation of NO.sub.x and SO.sub.x by said oxygen to yield nitric and sulphuric acids, a separator and reactor control unit for separation of products and liquids and controlling the reaction; and a vessel containing ammonia streaming said ammonia into the reactor or into the control unit to react with the nitric and sulphuric acids and to yield the fertilizers.

The present invention solves the existing problem of using very expensive oxidation reagents, such as H.sub.2O.sub.2 and ozone, in removal of NO.sub.x and SO.sub.x from flue gases, by performing simultaneous oxidation of NO.sub.x and SO.sub.x with atmospheric oxygen in a combined system for catalytic oxidation and wet-scrubbing of both NO.sub.x and SO.sub.x from a flue gas and manufacturing fertilisers. Two major configurations of the oxidation system are disclosed in the present invention. The first configuration operates on oxygen-enriched air to increase efficiency of the oxidation reaction and requires an additional oxygen concentrator unit. The second configuration operates on atmospheric air at ambient conditions and requires an additional catalyst activation unit. In the second configuration, the efficient oxidation process is carried out at low temperatures of about 30-90 C. in the presence of recovered and re-activated catalyst. This temperature is a result of the exothermic character of the reaction, and therefore, no heating is required in the process.

A process is presented where a feed stream containing a hydrogen sulfide and another feed component is introduced into an absorber that the feed stream flows upward from the bottom of the absorber and contacts a liquid treatment solution, where the liquid treatment solution contains a sulfur dye catalyst. The hydrogen sulfide is absorbed into the liquid treatment solution and converted into sulfide ions. The other feed component is removed from the absorber vessel substantially free of the hydrogen sulfide and a spent treatment solution is also removed from the absorber vessel and fed to an oxidation vessel where it is contacted with an oxygen containing gas causing the sulfide ions to oxidize to thiosulfate and converting the spent sulfur dye catalyst to regenerated sulfur dye catalyst. The thiosulfate is recovered, and the regenerated sulfur dye catalyst can be recycled as part of the liquid treatment solution.

The present application solves the existing problem of using very expensive oxidation reagents, such as H.sub.2O.sub.2 and ozone, in removal of NO.sub.x and SO.sub.x from the flue gases, by performing the NO.sub.x and SO.sub.x oxidation with atmospheric oxygen. The combined system for catalytic oxidation and wet-scrubbing of simultaneously both NO.sub.x and SO.sub.x from a flue gas and manufacturing fertilisers, comprises: (a) an air separation unit for separating atmospheric oxygen from air and thereby producing an air stream substantially enriched with atmospheric oxygen for oxidation of NO.sub.x and SO.sub.x, (b) an adsorption and oxidation reactor containing an oxidation catalyst and designed to receive said air stream and a flue gas stream containing NO.sub.x and SO.sub.x, to adsorb said streamed gases, and then to carry out the catalytic oxidation of said NO.sub.x and SO.sub.x by said oxygen to yield nitric and sulphuric acids, (c) a separator and reactor control unit for separation of products and liquids and controlling said catalytic oxidation and wet-scrubbing; and (d) a vessel containing gas or liquid ammonia, connected to said adsorption and oxidation reactor or to said separator and reactor control unit, and streaming said ammonia into the adsorption and oxidation reactor or into the separator and reactor control unit to react with the nitric and sulphuric acids and to yield ammonium nitrate and ammonium sulphate fertilisers.

A process is presented where a feed stream containing a hydrogen sulfide and another feed component is introduced into an absorber that the feed stream flows upward from the bottom of the absorber and contacts a liquid treatment solution, where the liquid treatment solution contains a sulfur dye catalyst. The hydrogen sulfide is absorbed into the liquid treatment solution and converted into sulfide ions. The other feed component is removed from the absorber vessel substantially free of the hydrogen sulfide and a spent treatment solution is also removed from the absorber vessel and fed to an oxidation vessel where it is contacted with an oxygen containing gas causing the sulfide ions to oxidize to thiosulfate and converting the spent sulfur dye catalyst to regenerated sulfur dye catalyst. The thiosulfate is recovered, and the regenerated sulfur dye catalyst can be recycled as part of the liquid treatment solution.

A process is presented where a feed stream containing a hydrogen sulfide and another feed component is introduced into an absorber that the feed stream flows upward from the bottom of the absorber and contacts a liquid treatment solution, where the liquid treatment solution contains a sulfur dye catalyst. The hydrogen sulfide is absorbed into the liquid treatment solution and converted into sulfide ions. The other feed component is removed from the absorber vessel substantially free of the hydrogen sulfide and a spent treatment solution is also removed from the absorber vessel and fed to an oxidation vessel where it is contacted with an oxygen containing gas causing the sulfide ions to oxidize to thiosulfate and converting the spent sulfur dye catalyst to regenerated sulfur dye catalyst. The thiosulfate is recovered, and the regenerated sulfur dye catalyst can be recycled as part of the liquid treatment solution.

A transformational energy efficient technology using ionic liquid (IL) to couple with monoethanolamine (MEA) for catalytic CO.sub.2 capture is disclosed. [EMmim.sup.+][NTF.sub.2.sup.?] based catalysts are rationally synthesized and used for CO.sub.2 capture with MEA. A catalytic CO.sub.2 capture mechanism is disclosed according to experimental and computational studies on the [EMmim.sup.+][NTF.sub.2.sup.?] for the reversible CO.sub.2 sorption and desorption.

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.

A method and apparatus for cleaning and recycling stack gas from coal-fired power plants, from natural or propane burning heating plants, or from cement kilns by using renewable catalysts of zeolite to separate pollutants into recyclable and reusable materials. The method reduces from the stack gas carbon monoxide (CO), carbon dioxide (CO.sub.2), nitrogen oxide (NOx), sulfur oxide (SOx) as well as halogens such as chloride and fluorides and trace metals particularly, mercury, lead, and zinc.