Abstract: Apparatus and methods for desulfurization of a sulfur-oxide containing gas by treatment with ammonia containing liquids. The apparatus and methods may utilize two distinct circuits of two different ammonia containing liquids which are applied in two distinct chambers. The gas may be cooled prior to entry into the circuits. There may be fluid communication between the two circulation circuits.

Abstract: Apparatus and methods for desulfurization of a sulfur-oxide containing gas by treatment with ammonia containing liquids. The apparatus and methods may utilize two distinct circuits of two different ammonia containing liquids which are applied in two distinct chambers. The gas may be cooled prior to entry into the circuits. There may be fluid communication between the two circulation circuits.

Abstract: A method is disclosed for manufacturing one or more oxygen scavenging particles, wherein the particle(s) comprises an oxidizable metal particle, such as elemental iron; an acidifying electrolyte such as sodium or potassium bisulfate and optionally a water hydrolysable Lewis acid, such as aluminum chloride. The method comprises the step of coating the oxidizable particle with a first compound and then reacting the first compound with a second compound to form a third compound, wherein the third compound promotes the reaction of the oxidizable particle with oxygen.

Abstract: Installation for gas treatment by a liquid phase comprising a) a column (C) that comprises means (1) for introducing gas at one end of said column, means (9) for drawing off gas from the other end of column (C) and, from upstream to downstream in the direction of circulation of the liquid phase: a first internal (2) that comprises means for distribution of a liquid phase, a first bed (6) that comprises a packing or catalytic particles, a second internal (3) that comprises means for separating liquid/gas mixture (19, 20) that is obtained from first bed (6), first means (32, 4) for collecting and evacuating the separated liquid phase, means (100) for passing through internal (3) of the treated gas, and distribution means (31, 101) of a liquid phase with said gas, a second bed (8), second means (10) for collecting and evacuating the liquid phase at the lower outlet of column (C), b) Means for recycling the collected liquid phase.

Abstract: Processes for selectively removing sulfur-containing compounds from a gas are described herein. The processes generally include contacting a first gas including carbon dioxide and hydrogen sulfide with a scrub solution including ammonium bisulfite and ammonium sulfite in a first contact zone to produce a first contact zone effluent liquid including ammonium thiosulfate and a first contact zone overhead gas in which the concentration of hydrogen sulfide is substantially reduced.

Abstract: Processes for selectively removing sulfur-containing compounds from a gas are described herein. The processes generally include contacting a first gas including carbon dioxide and hydrogen sulfide with a scrub solution including ammonium bisulfite and ammonium sulfite in a first contact zone to produce a first contact zone effluent liquid including ammonium thiosulfate and a first contact zone overhead gas including carbon dioxide.

Abstract: A process and apparatus for removing SO2 from a gas stream having the steps of scrubbing the SO2 with an ammonia scrubbing solution and removing any aerosols generated by the scrubbing in a wet electrostatic precipitator. The scrubbing solution is maintained at a pH between 6 and 8 to increase the speed of absorption of SO2, to Increase the ratio of sulfite to bisulfite which also facilitates the oxidation of SO2, and to avoid the need to use exotic, corrosion resistant alloys. Ammonium sulfate, a valuable fertilizer, can be withdrawn from the scrubbing solution.

Abstract: A process is provided for scrubbing sulfur dioxide out of a flue gas by contacting the flue gas with a scrubbing liquid containing diammonium phosphate and ammonium sulfite and in which the total concentration of phosphates is maintained in a balance with the total concentration of sulfites so that the formation and release of plumes of ammonium sulfite are minimized. The sulfur dioxide in the flue gas reacts with the diammonium phosphate to produce monoammonium phosphate and ammonium bisulfite. A portion of the scrubbing liquid is contacted with ammonium ions to convert the monoammonium phosphate into diammonium phosphate and the ammonium bisulfite into ammonium sulfite, and the same portion of scrubbing liquid is contacted with oxygen to convert the ammonium ammonium sulfite into ammonium sulfate. Ammonium sulfate is removed from the process and the oxidized scrubbing liquid is recycled for further contact with flue gas.

Abstract: SO.sub.2 containing flue gas is scrubbed with a scrubbing solution made up from ammonia water, untreated ammonium sulfate scrubbing solution recycled from the bottom of the scrubbing zone and ammonium sulfate solution formed by oxidizing a portion of the recovered ammonium sulfite scrubbing solution. The ammonium sulfite/ammonium sulfate mixing ratio is maintained at 15:1 to 3:1. The ammonium sulfite containing scrub liquid in combination with aqueous ammonia and an ammonium sulfate solution which has undergone oxidation can have an unusually high sulfur dioxide absorption capacity while minimizing the formation of aerosols.

Abstract: A method of wet flue gas desulfurization of combustion gases that incorporates both calcium scrubbing with forced oxidation and ammonia scrubbing of the gas in a scrubber tower. The end product or result from such a process is gypsum and ammonia sulfate which may be used in agriculture.

Abstract: Process for the removal of sulfur oxides from sulfur oxide-containing gas with simultaneous production of ammonium sulfate. The process is carried out by first passing hot sulfur oxide-containing gas through a prescrubber wherein the gas contacts saturated aqueous ammonium sulfate liquor which is recycled in the prescrubber, followed by passing the prescrubbed gas through an absorber wherein the prescrubbed gas contacts dilute aqueous ammonium sulfate liquor. The sulfur oxide in the sulfur oxide-containing gas is absorbed by the dilute aqueous ammonium sulfate liquor in the absorber, and scrubbed gas is removed from the absorber. The dilute aqueous ammonium sulfate liquor is treated with ammonia and air and the absorbed sulfur dioxide is converted to ammonium sulfate in the liquor. The dilute ammonium sulfate liquor is recycled into contact with the prescrubbed gas in the absorber.

Abstract: This invention relates to a process for catalytic oxidation of oxides of sulfur and also relates to oxidation of oxides of sulfur oxides and oxides of nitrogen.

Abstract: A process for the production of ammonium sulfate in a multistage contactor (or column) inclusive of liquid cyclone recycle. A gas, or gases, which contains sulfur dioxide, e.g., a flue gas, is contacted with ammonia in an oxygen and water environment in a column comprised of three sections (zones). Sulfur dioxide is contacted in vapor phase in a central section of the contactor with a stoichiometric excess of ammonia in the presence of oxygen and water vapor to produce ammonium sulfate. A scrubbing section for the removal of ammonia from the effluent gas by countercurrent contact with water or acid solution is provided in the upper section of the contactor. Liquid cyclones are utilized in the lower section of the contactor where product ammonium sulfate is removed as a slurry, crystalline ammonium sulfate is removed from the slurry, and liquid is returned as recycle to the contactor.

Abstract: A process for the removal of sulfur dioxide and other contaminants and the recovery of ammonium sulfate as a by-product from a hot waste gas stream comprising cooling the waste gas stream to a temperature below 120.degree. F., passing said waste gas stream in sequence through at least two separate absorption zones utilizing as an absorbent a recirculated aqueous salt solution of ammonium sulfite-bisulfite, withdrawing and oxidizing a portion of said aqueous ammonium sulfite-bisulfite salt solution under pressures and temperatures sufficient to substantially convert the salts to sulfate salts, and recycling the ammonia and sulfur dioxide vapors liberated during oxidation to the first absorption zone.

Abstract: Cuprous sulphate solutions, suitable for thermal or electrochemical disproportionation to yield copper, are obtained by dissolving copper sulphites, such as Chevreul's salt or cuprous ammonium sulphite, in acetonitrile-water or 2 hydroxycyanoethane-water mixtures, preferably in the presence of cupric sulphate. This discovery is capable of a number of applications, one of which is the recovery of copper from chalcopyrite by the following five steps. An oxidizing roast of chalcopyrite such as to produce either cupric sulphate and/or copper oxide, leaching of cupric sulphate from the calcine, precipitation of Chevreul's salt and/or other copper sulphites with a soluble salt of sulphurous acid, including bisulphites, dissolution of the copper sulphite as cuprous sulphate, using cupric sulphate in an acetonitrile-water solution as oxidant; precipitation of pure copper by thermal disproportionation of the cuprous sulphate solution. Acetonitrile and acidic cupric sulphate solution may be recycled.