Abstract: A process is provided for removing ammonia, hydrogen sulfide and hydrocyanic acid from gases such as coke oven gas. In carrying out the process, the gas to be cleaned is first washed with an alkaline solution to remove the hydrogen sulfide and hydrocyanic acid. The hydrogen sulfide is oxidized by air to produce elemental sulfur, which is removed, and the alkaline solution is recirculated for reuse, a portion of the solution carrying cyanide and other compounds being diverted for further treatment. The gas to be cleaned is subjected to a second washing operation with an inorganic acid solution which removes the ammonia from the gas by formation of an ammonia salt solution. The salt solution is regenerated to recover the acid which is recirculated for reuse.

Abstract: In purifying a gas containing at least one of hydrogen cyanide and hydrogen sulfide as a harmful component by fixing the harmful component in water as an aqueous solution of nitrogen-containing sulfur compound so as to render the gas free of the harmful component, an improvement characterized by:1. burning the aqueous solution of nitrogen-containing sulfur compound to obtain an exhaust gas containing sulfur dioxide,2. separating the sulfur dioxide from the exhaust gas for recovery, and3. exhausting the gas after the separation of the sulfur dioxide.

Abstract: A process is disclosed for removing impurities such as carbon dioxide, and sulfur dioxide from acidic fluid solutions using a serpentine material and producing a reaction product comprising recoverable metal values and finely divided silica. In accordance with the process, the serpentine material is slurried with water and is then mixed with an acidic fluid solution including at least one of H.sub.2 CO.sub.3 and H.sub.2 SO.sub.3. In particular, the acid material may be formed by contacting a gaseous component such as carbon dioxide or sulfur dioxide directly with water. A waste industrial gas containing carbon dioxide, sulfur dioxide, or a mixture of the two is an excellent source of gaseous components having utility in connection with this invention.

Abstract: An improved method and apparatus for removing carbon dioxide from the air in which the air is passed at a slightly elevated pressure over the surfaces of absorption elements impregnated with a carbon dioxide-absorbing liquid. The elements are corrugated plates, and the air flows transverse to the corrugations.

Abstract: An apparatus and process for substantially reducing carbon dioxide and/or hydrogen sulfide levels in a hydrocarbon gas with simultaneous regeneration of reagent materials are disclosed. The process consists of passing the gas through an aqueous sodium hydroxide solution, reacting the effluent liquid with an acidic reagent, stripping the acidic gases therefrom and subjecting the resulting aqueous sodium sulfate solution to an electrolytic process. The apparatus used to carry out the process comprises an acidic gas absorbing unit, means for reacting the resulting effluent liquid, means for stripping the acidic gases and an electrolytic cell to convert soluble alkali metal salts into the corresponding alkali metal hydroxide and acidic reagents.

Abstract: A method for removing hydrogen sulfide from a hydrogen sulfide entrained gas comprises the steps of bringing the hydrogen sulfide entrained gas into contact with an alkaline absorption solution with a pH of 10 to 14 to cause hydrogen sulfide in the gas to be absorbed into an alkaline absorption solution, subjecting the resultant absorption solution to a DC electrolytic treatment whereby an alkaline solution is separated into a cathode chamber and sulfur and sulfuric acid are separated into an anode chamber, and circulating as the alkaline absorption solution the alkaline solution produced within the cathode chamber. This constitutes a closed system, thereby completely eliminating a cause for public nuisance.

Abstract: A continuous process is provided for scrubbing hydrogen sulfide and ammonia from coke oven gases by selectively scrubbing the hydrogen sulfide using aqueous ammonia, then distilling the hydrogen sulfide again from the wash liquor combining the ammonia directly with acids or certain acid salts, e.g., sulfuric acid or ammonium bisulfate, liberating the combined ammonia therefrom by decomposition, and then recycling the released ammonia to the hydrogen sulfide scrubber, thereby increasing the ratio of ammonia to hydrogen sulfide therein. A preferred absorbent for ammonia is monoammonium phosphate.

Abstract: In the absorption of an acid gas by an aqueous alkaline solution under gas-liquid absorption conditions, undesirable foaming is reduced by contacting the aqueous solution in a separate contact zone with a hydrocarbon solvent containing an effective amount of an extraction adjuvant.

Abstract: A continuous process is provided which has the primary purpose of removing NH.sub.3, H.sub.2 S, HCN, and (CN).sub.2 from the subject gas mixtures and the secondary purpose of producing (NH.sub.4).sub.2 SO.sub.4 and iron oxide for industrial uses. The gas mixture which contains tar and other condensible vapors, NH.sub.3, H.sub.2 S, HCN, and (CN).sub.2 together with small volumes of gas from the ammonia still of the system, and gas from a system H.sub.2 SO.sub.4 plant, is contacted in a single three-stage reaction chamber in the presence, if need be, of a tar solvent, additional NH.sub.3, and the reagent Fe(OH).sub.2, which itself is a product of a concurrent reaction between NH.sub.3 and FeSO.sub.4. The unpurified gas mixture's condensible vapors are largely prevented from condensing by maintaining a steady, elevated temperature, while the mixture is essentially freed of HCN, (CN).sub.2, NH.sub.3, and H.sub.2 S in the reactor before the gas mixture passes through a primary gas cooler.

Abstract: A method of reducing foaming of a liquid containing dissolved carbon dioxide during filtering. The carbonated liquid to be filtered is adjusted in pH to a value of 6.5 to 8.0 by the addition of an alkaline material which reacts with the dissolved carbon dioxide to remove the carbon dioxide from solution. The elimination of the dissolved carbon dioxide results in decreasing foaming during filtering and substantially increases the rate of filtration.

Abstract: In a process for the dechlorination of gas mixtures containing carbon dioxide and chlorine, wherein in several absorption stages the chlorine is converted with stoichiometric alkali metal hydroxide solution into a carbonate-free alkali metal chloride-alkali metal hypochlorite solution and wherein the required stoichiometric amount of alkali metal hydroxide is introduced countercurrent to the gas stream via the last absorption stage, the improvement which comprises operating the last absorption stage in such a manner that due to free alkali metal hydroxide no alkali metal hydrogen-carbonate is present in said stage.

Abstract: A process for removing catalyst fines and acidic gases from a fluid catalytic cracking process regenerator gaseous effluent by scrubbing the effluent with an aqueous scrubbing mixture maintained within a critical pH range in a jet ejector venturi scrubbing system.

Abstract: Hydrogen sulfide-containing waste gases whose complete treatment is indispensable from the viewpoint of environmental pollution problem, are purified in two steps consisting of a first step in which the gases are absorbed in an aqueous solution of sodium hydroxide or/and sodium sulfide, and a second step in which sulfuric acid and sulfur dioxide gas are simultaneously introduced into the resulting solution after absorption to deposit sulfur. Further, for recovery of the resulting sulfur, a particular apparatus is provided.