Abstract: A straight-through four reactor system and process is disclosed for obtaining high levels of sulfur recovery from acid gas at a cost equal to or less than that required for a standard modified four reactor Claus system. Two conventional Claus reactors and two cold bed adsorption (CBA) reactors are in series. Four condensers are provided, one disposed before each of the Claus and CBA catalytic reactors. A first heater and a first bypass line is disposed between the second condenser and the second catalytic reactor (second Claus reactor) and a second heater and a second bypass line is disposed between the third condenser and the third catalytic reactor (first CBA reactor). The system is designed to operate either with both CBA reactors in a recovery mode or with one CBA reactor in a regeneration mode and the other CBA reactor in a recovery mode. When both reactors are operating in the recovery mode, the system is similar to the standard modified Claus system.

Abstract: Oxidation of chlorinated hydrocarbons ("CHC") is effected in a fluidized bed of alumina catalyst-support on which is deposited a "soft" metal as the active catalytic ingredient, and the bed is fluidized with a nitrogen-free oxygen-containing stream of HCl gas, in conjunction with steam. The steam, in a particular range of proportions relative to the HCl, stifles the production of free Cl without blinding the active catalyst sites so that conversion of the CHCs is always at least 95%. The process comprises contacting the CHCs in the vapor phase with a fluidized bed of a catalyst-support on which is deposited an effective amount of iron, or copper, or both, in an active form, sufficient to convert in excess of 95% of the CHC on a molar basis, and the bed is fluidized with HCl, superheated steam and oxygen substantially free of nitrogen.In a particular embodiment using a single ("catoxid") reactor, the effluent is purged of water, unconverted CHCs, CO.sub.

Abstract: A process for removal of H.sub.2 S from gaseous streams is described, the process being characterized by division of the gaseous stream into major and minor portions, oxidation of the H.sub.2 S in the major portion with an oxidizing reactant solution comprising a polyvalent metal chelate or chelates of nitrilotriacetic acid, and utilization of the minor portion as a source of hydrogen ions to assist precipitation of ferrous oxalate from a bleed stream of the oxidizing reactant solution.

Abstract: A process for the removal of oxalate ion from solutions containing polyvalent metal chelates of nitrilotriacetic and the decomposition products thereof is described, the process being characterized by the addition to such solutions of sufficient composition capable of providing hydrogen ion to precipitate ferrous oxalate, but not remove the bulk of the polyvalent metal chelate or chelates of nitrilotriacetic acid.

Abstract: A three catalytic reactor system and process is disclosed for obtaining acceptable levels of sulfur recovery from acid gas at a cost significantly less than that required for a standard modified four reactor cold bed adsorption (CBA) system. The system and process utilize two conventional Claus reactors and one cold bed adsorption (CBA) reactor in series. Four condensers are provided, one disposed before each of the catalytic reactors and one on a process line connecting the third catalytic (CBA) reactor to the first catalytic reactor. The system is designed to operate either in a normal adsorption mode or in a regeneration mode. In the normal adsorption mode, the second Claus reactor is operated at a closer sulfur dewpoint approach then the second Claus reactor in the standard CBA system. In the regeneration mode, gas downstream of the thermal reactor is directed first to the second Claus reactor and then, after removal of sulfur and reheating, to the CBA reactor.

Abstract: A desulfurization process for hydrogen sulfide-containing gases, which comprises contacting an alkaline aqueous medium containing a naphthoquinone sulfonate, a water-soluble compound of at least one polyvalent metal selected from the group consisting of iron, manganese, vanadium and copper, and a water-soluble high molecular compound having weight-average molecular weight of from 300 to 50,000 with a hydrogen sulfide-containing gas thereby causing the hydrogen sulfide in said gas to be absorbed by said aqueous medium and subsequently contacting said aqueous medium now containing the absorbed hydrogen sulfide with a molecular oxygen-containing gas thereby separating elementary sulfur from said hydrogen sulfide.

Abstract: The present invention relates to the recovery of heat values, including sensible heat and/or combustion heat, from vitiated gaseous mixtures containing oxygen and/or combustibles together with inert diluents in which a supplemental fuel is burned, in a combustion zone or the first stage of a two-stage, rich-lean combustion zone, the vitiated gaseous mixture is mixed with the combustion products at the downstream end of the combustion zone or the first stage of the two-stage combustion zone, as the case may be, and the effluent of the combustion is passed to a heat utiization zone.

Abstract: The selective removal of H.sub.2 S gas from a normally gaseous mixture containing H.sub.2 S and CO.sub.2 is accomplished by contacting the gaseous mixture with an absorbent solution comprising a nitrogen heterocyclic tertiary aminoalkanol or aminoetheralkanol whereby H.sub.2 S is selectively absorbed from the mixture.

Abstract: A three catalytic reactor system and process is disclosed for obtaining acceptable levels of sulfur recovery from acid gas at a cost significantly less than that required for a standard four reactor cold bed adsorption (CBA) system. The system and process of the present invention utilizes two conventional Claus reactors and one cold bed adsorption (CBA) reactor in series. Four condensers are provided, one disposed before each of the catalytic reactors, and one on a process line connecting the third catalytic (CBA) reactor to the first catalytic (Claus) reactor. The system is designed to operate either in an adsorption mode or in a regeneration mode. In the adsorption mode, the system is similar to a standard CBA system except that the present invention incorporates only one CBA reactor while a standard CBA system incorporates two CBA reactors. In the regeneration mode, however, the CBA reactor of the present invention is operated in the same manner as the first Claus reactor in adsorption mode.

Abstract: A process for reacting the H.sub.2 S in H.sub.2 S-bearing gas streams with SO.sub.2 in a solvent to produce elemental sulfur, including the steps of oxidizing approximately 1/3 of the H.sub.2 S in the stream to SO.sub.2, absorbing that SO.sub.2 with a dialkyl alkyl phosphonate absorbent and reacting that SO.sub.2 with the remaining H.sub.2 S from the stream in the presence of the phosphonate solvent, thereby forming elemental sulfur and water.

Abstract: Process for removal of sulfur compounds from gases by passing the gases over an absorption mass which, on an inert support having a specific surface area of more than 10 m.sup.2 per g, contains metal oxides which react with hydrogen sulfide to give metal-sulfur compounds and at least 20% by weight of which metal oxides are present in finely divided form with a particle size of less than 40 nm. The gases are passed at a temperature of 5.degree. to 800.degree. C. over the support loaded with metal oxide, and the resultant support loaded with metal-sulfur compounds is regenerated by passing gases containing oxidizing agents over it.

Abstract: An oxidation catalyst for use in a catalytic exhaust gas purification unit comprises a substrate on which a refractory metal oxide is coated, a base metal component and one or more metals from the Platinum Group. The catalyst is highly effective when a metallic substrate is employed and the loading of the refractory metal oxide coating is relatively high. The base metal is useful for catalysts having a ceramic substrate and a relatively low coating loading.

Abstract: Emissions from sulfur pits or other vessels containing molten sulfur are prevented or minimized by use of an air purge drawn into the vessel from the atmosphere and subsequently utilized as a portion of the oxidant required in a process for oxidizing hydrogen sulfide to elemental sulfur.

Abstract: A process and catalyst is disclosed for the reduction of the ignition temperature of diesel soot filtered out of the exhaust fumes of diesel engines by passing the exhaust stream through a filter element. The filter element is a temperature resistant inert support onto which is deposited a catalytically effective amount of silver vanadate or a mixture of the temperature resistant carrier material and a catalytically effective amount of silver vanadate.

Abstract: A method is disclosed for recovering carbon dioxide from gases containing the same as well as oxygen and/or sulfur compounds employing aqueous 5 to 80% alkanolamine solutions. Corrosion of the metals of construction and solvent degradation are minimized by the use of copper ion maintained in solution and continuous removal of ionic iron and solvent degradation products by treating the solvent or a portion of the solvent with a carbon bed, mechanical filter and/or a anion exchange resin.

Abstract: A process of separating in multiple stages acid components in coke oven gas such as CO.sub.2, HCN and particularly H.sub.2 S by ammonia scrubbing wherein the ammonia used in scrubbing is deacidified to remove the acid components and is recirculated to the scrubbing process at least in part as substantially pure liquid ammonia.

Abstract: Use of ferri-magnetic reactive iron oxide particles to react hydrogen sulfide in water, hydrocarbon liquids or drilling mud affords quick, effective scavenging of these liquids without accumulation of particulate matter and without wasting the reactive particles. The reaction product is environmentally safe, so that it may be disposed of on a simple waste heap.A quantity of the magnetic iron oxide particles, principally a synthetic porous Fe.sub.3 O.sub.4, is suspended in the liquid. The quantity added is in excess of that required for the reaction with the hydrogen sulfide in order to speed the reaction time and provide a large margin of safety. In use, the reactive iron oxide particles contact and react the hydrogen sulfide, forming a non-magnetic particulate product of reaction. Thus, if used to scavenge a drilling mud, this contact and reaction occurs as the mud, bearing the drill cuttings, rises through the drilling formation.

Abstract: Hydrogen sulfide and hydrogen cyanide are catalytically removed from air at room temperatures. Air containing H.sub.2 S and HCN in dilute concentrations is contacted with a dry, activated catalyst formed of palladium (II) and copper (II) salts such as chlorides, on an alumina substrate, at a temperature in the range of -20.degree. C. to 85.degree. C. The catalyst may also contain nickel (II) chloride.

Abstract: An alcohol and carbon monoxide are produced by the decarbonylation of an alkyl formate in the presence of, as catalyst, (i) a Lewis base and epoxide or (2) an amidine or a guanidine. When the Lewis base used is a trivalent phosphorus compound, for example a phosphine, it is preferable to have alcohol present at the start of the reaction.

Abstract: Claus plant tail gas is treated to further reduce sulfur content by hydrogenating all sulfur compounds to hydrogen sulfide, pressurizing the resulting stream and cooling to reduce water content therein, and removing hydrogen sulfide from the resulting stream of reduced water content.