Abstract: A process for the removal of H.sub.2 S from sour gaseous streams is disclosed in which the sour gaseous stream is contacted with a solution containing solubilized iron chelates of nitrilotriacetic acid. The contacting is carried out in first and second contacting zones, the first being a gas-solution mixture formation zone and the second comprising a plurality of contacting sections adapted to provide reaction of the H.sub.2 S in the sour gaseous stream with the iron in the contacting solution without plugging due to deposition of sulfur.

Abstract: A process for the removal of H.sub.2 S from sour gaseous streams is disclosed in which the sour gaseous stream is contacted with a solution containing solubilized iron chelates of a specified organic acid or acids. The contacting is carried out in first and second contacting zones, the first being a gas-solution mixture formation zone and the second comprising a plurality of contacting sections adapted to provide reaction of the H.sub.2 S in the sour gaseous stream with the iron in the contacting solution without plugging due to deposition of sulfur.

Abstract: In purifying gas wash waters containing cyanide with formaldehyde, the exact dosing of formaldehyde presents a problem, especially with strongly fluctuating cyanide contents. By continuous potentiometric measurement in a side stream which is regulated to a pH of 7 to 10, while the pH of the main stream remains unchanged, the formaldehyde can be adjusted safely to any cyanide content.

Abstract: Organic sulphides are extremely malodorous compounds that are found in gaseous or aqueous effluents from many industries such as paper and pulp manufacture, hydrocarbon refinering, tanneries, and in the synthesis of organic sulphur compounds. Their removal is necessary before such effluents can be discharged into the environment.In the present invention their removal is effected using hydrogen peroxide at a pH controlled to pH 8.5 to 11.5 and in the presence of a catalytic amount of a soluble tungstate. Such a process is especially applicable to the removal of dialkyl disulphides, which are regarded as being especially difficult to remove oxidatively. In especially preferred conditions, the pH is about pH 11 and about 3-4 moles H.sub.2 O.sub.2 is used per mole equivalent of sulphur, in the presence of at least 20 ppm sodium tungstate (as W).

Abstract: A desulphurization apparatus and method for natural gas in which red iron oxide is reacted with the sulphur compounds found in natural gas to remove these compounds from the gas. The treating solution is then recycled to regenerate the red iron oxide solution with elemental sulphur formed as a byproduct for removal.

Abstract: Geothermal wells are drilled and the raw steam containing H.sub.2 S gas and debris that is released is treated with an aqueous solution containing ferric chelate and one or more water soluble cationic polymeric catalysts to remove substantially all of the H.sub.2 S and the debris is removed in a settling zone. The polymeric catalysts accelerate the oxidation of sulfide ions to sulfur solids.

Abstract: A composition and process for the removal of mercaptans from gaseous mixtures, particularly gaseous mixtures containing hydrocarbons, wherein the gaseous mixture is treated with an aqueous solution of a water soluble nitrite, such as sodium nitrite, and a water soluble polysulfide, such as sodium tetrasulfide, the pH of the aqueous solution preferably being about 10 or greater initially.

Abstract: A process is disclosed for the cleaning of a clogged packed column. The packed column is utilized for gas cleaning in a scrubbing operation carried out with a scrubbing medium, and becomes plugged by deposits which form during operation. In order to be able to effectively and economically break up these deposits, the packed column is flooded, e.g., with a scrubbing medium, wherein the flooding fluid has a specific gravity greater than that of the particles of packing material. During the flooding of the packing, the deposits are broken up by flotation of the packing material. Preferably, the packed column can thus be utilized in scrubbing out H.sub.2 S in an oxidative scrubbing process in which sulfur deposits form.

Abstract: The invention relates to a process for the selective removal of hydrogen sulfide from a gaseous stream additionally containing carbon dioxide by contacting the gaseous stream with a polyvalent metal chelate solution for a time sufficient to allow the polyvalent metal chelate to oxidize the hydrogen sulfide to elemental sulfur without allowing the polyvalent metal chelate solution to absorb appreciable amounts of carbon dioxide. The pH of the metal chelate solution should be greater than 7 and the contact time between the polyvalent metal chelate and the gaseous stream is between 0.006 and 0.08 second.

Abstract: Waste gases and other noxious substances which are formed in connection with chemical processes and the manufacture of devices such as semiconductors and covalent hydrides and element organic compounds, etc. are treated so as to remove the noxious components.

Abstract: Process for the treatment of waste water and gases containing dialkyl disulphides by catalytic oxidation of these compounds by means of a peroxide compound in an aqueous medium. Divalent copper ions are used for the catalyst and the medium is kept at a pH below 6.5.

Abstract: Catalysts comprising bismuth and vanadium components are highly active and stable, especially in the presence of water vapor, for oxidizing hydrogen sulfide to sulfur or SO.sub.2. Such catalysts have been found to be especially active for the conversion of hydrogen sulfide to sulfur by reaction with oxygen or SO.sub.2.

Abstract: A process for removing hydrogen sulfide from saturated steam is described whereby the steam and hydrogen sulfide entrained therein are contacted under conditions of turbulent flow with hydrogen peroxide. The effectiveness of the process is improved by simultaneously contacting the steam with a basic reagent such as sodium hydroxide.

Abstract: A process is set forth for the selective removal of acid gases such as H.sub.2 S, COS and CO.sub.2 from a gas stream by contacting the stream with a bis tertiary amino alkyl solvent compound such as 4,4'-(oxydi-2,1-ethanediyl) bismorpholine. When used in an aqueous solution, the compounds catalytically hydrolyze COS to H.sub.2 S and CO.sub.2.

Abstract: A method for preferentially oxidizing sulfide in a viscous, aqueous solution of a hydratable polymeric material suitable for use in hydraulically treating subterranean formations.

Abstract: A process and apparatus for removing total reduced sulfur compounds (TRS), especially H.sub.2 S and mercaptans from industrial gases is disclosed wherein an aqueous suspension of an active manganese dioxide is contacted with the industrial gas by atomizing the aqueous suspension in a spray dryer and contacting the atomized droplets with the industrial gas at a temperature sufficient to substantially completely evaporate the water in the atomized droplets. In preferred practice, the dried powder produced by the spray dry process is recovered as a particle layer in a bag filter unit through which the industrial gas is caused to flow.

Abstract: A process for deodorizing polluted air, wherein the air to be deodorized is washed in a washing apparatus with an aqueous solution of hydrogen peroxide. The solution is circulated in a closed circuit while ozone is introduced either directly into the air to be treated or directly into the aqueous solution which is thus regenerated. The initial weight percentage of hydrogen peroxide in the aqueous solution is within the range of 0.5% to 10%.

Abstract: A process is provided for substantially complete elimination of hydrogen sulphide from the organic phase of natural gas, crude oil or mixtures thereof, by reaction with aqueous hydrogen peroxide in the absence of any catalyst or organic compounds or of compounds that yield them at a pressure of at least 90 kPa gage. The process is particularly useful with crude materials as they are pumped directly from the earth.

Abstract: A unique process arrangement is disclosed wherein the effluent flue gas from the removal of hydrocarbonaceous coke from particulate matter by combustion in a mixture of pure oxygen diluted with carbon dioxide is processed to provide a carbon dioxide-rich recycle gas stream to be mixed with oxygen as regenerator feed gas; and a net combustion product stream from which are recovered SO.sub.x and NO.sub.x to eliminate atmospheric emissions, and a pure CO.sub.2 product for export. An alternate embodiment also produces hydrogen or synthesis gas for export.

Abstract: A process for afterburning and purifying process exhaust gases, which contain combustible constituents, wherein the process exhaust gases and the oxygen-containing gases required for a combustion are separately supplied to a fluidized bed reactor of a circulating fluidized bed. In the fluidized bed reactor, the gas velocity is adjusted to 2 to 10 m/s (empty pipe velocity), the mean suspension density is adjusted to 0.1 to 10 kg/m.sup.3, the temperature is adjusted to 700.degree. to 1100.degree. C., and the stoichiometric ratio of gas-purifying agent having a particle size d.sub.p 50 of 30 to 200 .mu.m to pollutant contained in the process exhaust gas or formed by the combustion is adjusted to 1.2 to 3.0, calculated as Ca:S. The entrained solids in the gases from the fluidized-bed reactor are recycled to the reactor at a rate of at least 5 times the weight of solids contained in the fluidized bed reactor per hour.

Abstract: For the simultaneous absorption and oxidation of hydrogen sulfide, gaseous mixtures substantially free of molecular oxygen are scrubbed in a first stage with an aqueous, alkaline scrubbing agent containing pentavalent vanadium as the oxidizing medium. The hydrogen sulfide is absorbed by the scrubbing agent and oxidized to elemental sulfur with reduction of pentavalent vanadium to tetravalent vanadium. The thus-reduced scrubbing agent is then regenerated in a separate second stage in the presence of an amine promoter by reoxidation of the tetravalent vanadium with molecular oxygen, and reused.

Abstract: An improved solid-liquid separation step for use in connection with the Stretford process introduces a small amount of an additive which is then emulsified and mechanically treated in a colloid mill or processed through an air dissolver before introduction into a flotation cell. The process uses dissolved air and/or dispersed air to float the elemental sulfur while simultaneously regenerating the Stretford solution for recirculation.

Abstract: A process for removing hydrogen sulfide from geothermal steam and from vent streams, or concentrated portions produced by a hydrogen sulfide separation process, includes the steps of introducing an oxygen-containing gas, such as air into the steam, or vent stream, and thereafter contacting the steam and oxygen-containing gas in a contacting stage with iron oxide supported by a carrier resistant to deterioration. The steam having a temperature of at least 250.degree. F. is mixed with oxygen to provide a molar ratio of oxygen-to-hydrogen sulfide ratio of less than about 10. During the contacting stage the pressure of the steam and oxygen-containing gas is maintained at a pressure sufficient to enable removal of a majority of the hydrogen sulfide from the steam and oxygen-containing gas.

Abstract: An indirect hydrogen sulfide conversion process for the production of elemental hydrogen and sulfur. The process is based upon the electrochemical oxidation of iodide in an aqueous solution with a pH in the range of 0 to 1 at high current densities and current efficiencies. Hydrogen gas is produced concurrently with soluble triiodide. Treatment of a gaseous or non-aqueous liquid stream with electrolyte solutions containing triiodide yields a sulfur product in plastic form. The sulfur product can be recrystallized from a solvent to yield sulfur of comparable purity to that presently produced.

Abstract: In a continuous process for the removal of H.sub.2 S from a gaseous mixture involving: (a) simultaneous absorption and oxidation of H.sub.2 S to form elemental sulfur; (b) regeneration of the oxidizing agent, e.g., vanadate, by treating the used scrubbing liquid with air; and (c) recycling the regenerated scrubbing liquid to the scrubbing step, to avoid the formation of sulfates and thiosulfates, the dissolved oxygen is substantially prevented from appearing in the scrubbing solution before reuse.

Abstract: A cyclic process and composition for the removal of hydrogen sulfide from a variety of gas streams is disclosed. The gas stream containing the sour gases is contacted with a specified reactant solution and a combination crystal modifier of phosphate and thiosulfate ions. The hydrogen sulfide is converted to sulfur, and the reactant is reduced. The process includes sulfur removal and regeneration of the reactant.

Abstract: A cyclic process and composition for the removal of hydrogen sulfide from a variety of gas streams is disclosed. The gas stream containing the sour gases is contacted with a specified reactant solution and a combination crystal modifier of phosphate and thiosulfate ions. The hydrogen sulfide is converted to sulfur, and the reactant is reduced. The process includes sulfur removal and regeneration of the reactant.

Abstract: A Stretford process for removing hydrogen sulfide collects a horizontal pool of liquid downstream of the primary gas/liquid contactor and accelerates a multiphase flow along the surface of that pool and along a serpentine path. Additional gas-liquid contact is effected by the interaction of multiphase flow and structural components establishing the pool and causing the acceleration.

Abstract: A method is provided for removing elemental sulfur particles from a hydrogen sulfide removal process which employs a regenerable, aqueous washing solution capable of absorbing hydrogen sulfide from an industrial gas stream and converting that hydrogen sulfide to elemental sulfur. The washing solution of such a process is contacted with bubbles of an oxygen-containing gas while in the presence of controlled concentrations of a selected hydrocarbon and a selected surfactant.

Abstract: Essentially all of the H.sub.2 S in steam which also contains up to 30 ppmw of CO.sub.2 per ppmw of H.sub.2 S can be scrubbed from the steam with aqueous NaOH or Na.sub.2 CO.sub.3 without consuming more than about 4 mols of NaOH or 2 mols of Na.sub.2 CO.sub.3 per mol of H.sub.2 S and without consuming more than about 0.18 pounds of water per pound of steam scrubbed, if (1) the steam is scrubbed countercurrently in a tower containing a contacting means equivalent to at least 6 theoretical stages, (2) the sulfide species in the tower effluent are completely oxidized to sulfo species and (3) the oxidized effluent--less a bleed stream and plus water and base makeup--is recycled to the tower. If the steam is scrubbed in this manner before being introduced to the turbines in a power plant, the exhaust from the turbines can be vented to the atmosphere without further treatment. The method of the invention is particularly suited for use at the Geysers geothermal "steam" field in California.

Abstract: Hydrogen sulfide is removed from a gas stream by injecting an alkaline solution into the gas stream. The velocity of the gas stream is such that it has a Reynolds number of at least 50,000 and the Weber number for the injected alkaline solution is at least about 16. Alkali metal hydroxides and polyvalent metal chelates are useful alkaline solutions.

Abstract: For avoiding equipment fouling from metal sulfide deposition in the processing of cracked gases containing H.sub.2 S and CO, the reactive metal species capable of carbonyl formation are prevented from contacting equipment parts operating within a temperature range favoring the formation of metal carbonyls, e.g., 30.degree.-250.degree. C. To accomplish this, the cracked gas is subjected to solids separation to remove dust particles containing the reactive metal species, or the cracked gas is oxidized to inactivate the metal species. Cooling water is also subjected to a preceding step of removing the reactive metal species.

Abstract: In the removal of sour gases, H.sub.2 S in particular, from CO-containing gaseous mixtures containing heavy metal carbonyls by scrubbing under pressure at temperatures of below 0.degree. C. with a scrubbing medium, the scrubbing medium is regenerated by inter alia, being heated by means of heat exchangers, and such exchangers are normally fouled by precipitates of metal sulfides which owe their presence to the decomposition of the metal carbonyls to form reactive heavy metal which combines with sulfide ion. To avoid fouling of the heat exchangers, the CO partial pressure is increased during the heating of the loaded scrubbing medium, to above the partial pressure of the CO in equilibrium with the carbonyls in the scrubbing medium thereby preventing the decomposition of the carbonyls.

Abstract: A method for reducing concentrations of hydrogen sulfide present in subterranean well fluids by injection of a stabilized solution of chlorine dioxide. The stabilized chlorine dioxide solution is introduced into the subterranean well by injecting the solution through the well bore. This method also includes the reduction of the hydrogen sulfide content in drilling mud which has been contaminated by hydrogen sulfide present in a hydrocarbon well by mixing a stabilized solution of chlorine dioxide with the drilling mud. This method requires the preparation of a stabilized chlorine dioxide solution, a determination of the approximate amount of hydrogen sulfide which might be brought to the surface by the drilling mud and the introduction of the predetermined amount of stabilized chlorine dioxide solution into the drilling mud.

Abstract: Gas is yielded and may be subsequently withdrawn from a subsurface formation of hydrocarbon material by passing a controlled amount of current from a direct source through the formation. The gas produced by this process has a high quality Btu content and is produced, in situ, under relatively moderate operating conditions. Furthermore, the gas yielded by this method has a reduced amount of hydrogen sulfide present therein.

Abstract: An integrated system for the derivation of useful energy from impure steam and/or for use in connection therewith, said steam containing both hydrogen sulfide and an alkaline acting component, such as ammonia, while producing liquid-phase and gaseous-phase effluents from condensation of the impure steam and substantially reducing the emission of sulfur-containing compounds to the environment. Treatment of such effluents to selectively react or bind alkaline acting components in the liquid-phase results in an augmented concentration of hydrogen sulfide in the gaseous-phase and its depletion in the liquid-phase. The gaseous-phase comprising noncondensable gas contaminants and uncondensed water vapor is separated from the liquid-phase steam condensate and treated to remove hydrogen sulfide to produce an environmentally acceptable vent gas which the in part is employed in said treatment of the liquid-phase effluent.

Abstract: The invention relates to a finishing process for the removal of low level concentrations of mercaptans, sulfides and disulfides from a gas stream, especially a natural gas stream. The sulfur compounds are washed from the gas stream with a solution containing hydrogen peroxide, sodium carbonate or sodium hydroxide, and ammonia or an amine.

Abstract: The present invention provides an apparatus and process for separating and removing chemical impurities from air which impurities are difficult to absorb. The apparatus for carrying out the process of the present invention comprises a reaction tower (11, 51, 91) into which the air-gas mixture is fed, aperture means (35, 74, 96) in a wall (16, 60, 98) of the tower, at least one filter means (12, 52, 92) carried in the reaction tower, means for distributing (13, 58, 93) an absorbent medium onto the filter, collecting means (14, 54, 94) beneath the filter for collection of the absorbent medium passing through the filter, and fan means (15, 55, 95) provided in the aperture for creating a flow of air through the reaction tower for the separation of substantially all of the impurities therefrom.

Abstract: A process for removing hydrogen sulfide from sour gas streams is disclosed which is carried out in processing equipment which includes steel components resulting in iron from the steel slowly dissolving in the alkaline H.sub.2 S absorption medium. The solubilized iron tends to react with the hydrogen sulfide to form iron sulfide which further oxidizes to produce sodium thiosulfate. The preferred absorption medium includes a metal vanadate and boron complex, a quinone type reoxidation catalyst and a metal ferri or ferrocyanide decahydrate compound capable of reacting with the solubilized iron in the alkaline absorption medium to form a precipitate which is unreactive with the dissolved hydrogen sulfide.

Abstract: An aqueous oxidation-reduction composition and method for removing hydrogen sulfide gas from a fluid stream by liquid phase oxidation of the hydrogen sulfide to elemental sulfur with a chelated polyvalent metal catalyst, such as iron, wherein the composition is stabilized against rapid loss of chelated polyvalent catalyst caused by contamination of the aqueous composition with micro-organisms, such as bacteria. The aqueous composition is stabilized by incorporating in the aqueous composition and adding throughout the normal usage thereof a broad spectrum biocide in an amount which acts as a bacteriostat to prevent rapid growth of bacteria in the aqueous composition and when the bacteria concentration rises above about 1.times.10.sup.6 colonies per ml.

Abstract: Fluid streams containing hydrogen sulfide from a steam turbine or from a sour gas stream are contacted with an aqueous solution of a polyvalent metal chelate and an oxidizing agent whereby the hydrogen sulfide is converted to free sulfur and then to soluble sulfur compounds. The metal chelate is reduced to a lower oxidation state metal chelate and reduced metal chelate is subsequently oxidized with air back to the higher oxidation state and reused.

Abstract: A process for the recovery of nitrilotriacetic acid values from solutions containing polyvalent metal complexes of nitrilotriacetic and the decomposition products thereof is described, the process being characterized by the addition to such solutions of sufficient strong acid to dissociate the complex under conditions to precipitate the nitrilotriacetic acid.

Abstract: A process for the removal of H.sub.2 S from sour gas streams is described, the process being characterized by the utilization of washing solutions containing oxidizing polyvalent metal chelates of specified aminocarboxylic acids, and by the electrolytic regeneration of spent solutions. Use of an optional CO.sub.2 -selective absorbent in the washing solution is also disclosed.

Abstract: A process for the removal of H.sub.2 S from sour gas streams is disclosed, the process being characterized by the use of a washing or contacting solution containing oxidizing polyvalent metal chelates of specified aminocarboxylic acids, the electrolytic regeneration of spent solution, and the co-production of hydrogen. Provision is also made for selective absorption of CO.sub.2.

Abstract: A process for the removal of H.sub.2 S from sour gas streams is disclosed, the process being characterized by the use of a washing or contacting solution containing oxidizing polyvalent metal chelates of nitrilotriacetic acid, the electrolytic regeneration of spent solution, and the co-production of hydrogen.

Abstract: A process for the removal of H.sub.2 S from sour gas streams is described, the process being characterized by the utilization of washing solutions containing oxidizing polyvalent metal chelates of specified amino-carboxylic acids, and by the regeneration of the spent solutions in a fuel cell mode.

Abstract: A process for the removal of H.sub.2 S from sour gas streams is disclosed, the process being characterized by the utilization of washing solutions containing oxidizing metal chelates of nitrilotriacetic acid, and by the electrolytic regeneration of the spent solutions.

Abstract: A process for the removal of H.sub.2 S from sour gas streams is described, the process being characterized by the utilization of washing solutions containing oxidizing polyvalent metal chelates of nitrilotriacetic acid, and by the regeneration of the spent solutions in a fuel cell mode.

Abstract: In the simultaneous scrubbing and oxidation of H.sub.2 S with a vanadate-containing aqueous alkaline scrubbing agent, so as to prevent precipitation of vanadium values, the concentration of CO.sub.3 -- ions in the scrubbing agent is adjusted, preferably to a minimum content of CO.sub.3.sup.-- ions of 12.5 g/l of scrubbing agent. The scrubbing agent is regenerated conventionally by treatment with an oxygen-containing gas in an oxidizer.

Abstract: In the scrubbing and simultaneous oxidation of hydrogen sulfide with an aqueous alkaline scrubbing solution containing five-valent vanadium as the oxidizing agent, the sulfide being converted into higher oxidation states with simultaneous reduction of the five-valent vanadium to four-valent vanadium, the scrubbing solution subsequently being regenerated for reuse in a downstream oxidizer by treatment with an oxygen-containing gas for the reoxidation of the four-valent vanadium, to avoid losses of vanadium when the pH in the scrubbing solution is below 9.5, using the vanadium in a ration which exceeds the stoichiometric ratio for the oxidation of the hydrogen sulfide.