Abstract: The present invention provides a method for producing hydrocarbon fuels with ultra-low levels of sulfur. The method involves catalytic oxidation of the sulfurous compounds within the hydrocarbon fuel, followed by extraction of the oxidized (and polarized) sulfurous compounds using a polar solvent. The present invention teaches the involvement of ethanol during catalytic oxidation. In this way, the oxidation catalyst has a dual-role in the oxidation process: firstly the catalyst directly oxidizes the sulfurous compounds, and secondly the oxidation catalyst converts of a small portion of the alcohol to the corresponding peroxy acid, which also helps to drive the oxidation process.

Abstract: A process for decreasing the amount of sulfur in a petroleum stream.

Abstract: The object of the present invention is a process for the elimination of sulphur compounds from the gasoline fraction, characterized in that it comprises carrying out an oxidation reaction of said sulphur compounds using at least one organic-inorganic composite as a catalyst which comprises at least:

Abstract: A process for the production of naphtha streams from cracked naphthas having sulfur levels which help meet future EPA gasoline sulfur standards (30 ppm range and below).

Abstract: The present invention related to a process for sweetening of LPG light petroleum distillates by liquid liquid extraction using metal phtalocyanine sulphonamide catalyst which comprises extracting the mercaptanes contain in LPG, light petroleum distillate like pentanes, light straight run naphtha by liquid-liquid extraction using an aqueous or alcoholic solution of alkali metal hydroxide of concentration ranging between 1 wt % to 50 wt % in the presence of a metal phthalocyanine sulphonamide catalyst in the concentration ranging from 5-4000 ppmw, at a temperature ranging from 10° C. to 80° C. at a pressure ranging from 1 kg/cm2-50 kg/cm2 in a continuous or batch manner, converting the mercaptanes present in above said extract into corresponding disulphides by passing air, oxygen or any oxygen containing gas at the above same temperature and pressure, regenerating the alkali solution containing catalyst for recycling by separating the upper layer of disulphides from said alkali solution of catalyst.

Abstract: Sulfur species are removed from hydrocarbon fluids by a process that includes contacting the fluid with a solid adsorbent having a porous substrate impregnated with silver oxide. The solid adsorbent preferably comprises activated alumina. The solid adsorbent may be regenerated with a two step process including: 1) heating the adsorbent in an inert atmosphere, preferably an atmosphere containing nitrogen, so that sulfur species are stripped from the adsorbent without oxidizing them, and 2) heating the adsorbent in an oxidizing atmosphere, preferably an atmosphere containing approximately 20% oxygen, so that the silver contained on the adsorbent is re-oxidized, forming silver oxide.

Abstract: This invention relates to reducing the amount of thiols (mercaptans) in petroleum streams, specifically, mercaptans above the five carbon molecular weight range.

Abstract: The demercaptanizaiton of petroleum distillates can be carried out by sorption of the mercaptan with activated carbon and oxidation of the sorbed mercaptan to disulfide at between approximately 20° C. to 55° C. The activated carbon used in the process is commercially readily available. Its surface area typically ranges from between approximately 500 to 1500 m2/g and has substantial percentage of the pores in the 10 to 100 Angstrom range.

Abstract: The present invention relate to a process for sweetening of LPG, light petroleum distillates by liquid-liquid extraction using metal phthalocyanine sulphonamide catalyst which comprises extracting the mercaptanes contained in LPG, light petroleum distillate like pentanes, light straight run naphtha by liquid-liquid extraction using an aqueous or alcoholic solution of alkali metal hydroxide of concentration ranging between 1 wt % to 50 wt % in the presence of a metal phthalocyanine sulphonamide catalyst in the concentration ranging from 5-4000 ppmw, at a temperature ranging from 10° C. to 80° C., at a pressure ranging from 1 kg/cm2-50 kg/cm2 in a continuous or batch manner, converting the mercaptanes present in above said extract into corresponding disulphides by passing air, oxygen or any oxygen containing gas at the above same temperature and pressure, regenerating the alkali solution containing catalyst for recycling by separating the upper layer of disulphides from said alkali solution of catalyst.

Abstract: The invention relates to a process for the production of gasoline with a low sulfur content that comprises at least the following stages:

Abstract: A method for reducing the level of elemental sulfur from sulfur-containing hydrocarbon streams as well as reducing the level of total sulfur in such streams. Preferred hydrocarbon streams include fuel streams such as naphtha streams that are transported through a pipeline. The sulfur-containing hydrocarbon stream is contacted with a mixture of water, a caustic, at least one metal sulfide, and an aromatic mercaptan. This results in an aqueous phase and a hydrocarbon phase containing reduced levels of both elemental sulfur and total sulfur.

Abstract: The demercaptanizaiton of petroleum distillates can be carried out by sorption of the mercaptan with activated carbon and oxidation of the sorbed mercaptan to disulfide at between approximately 20° C. to 55° C. The activated carbon used in the process is commercially readily available. Its surface area typically ranges from between approximately 500 to 1500 m2/g and has substantial percentage of the pores in the 10 to 100 Angstrom range.

Abstract: The general object of this invention is to provide an improved process for sweetening and desulfurizing sulfur-containing crude oil streams. Heating the sulfur-containing crude oil stream to an elevated temperature for an extended period of time while stirring and bubbling an inert gas into the crude accelerates the removal of sulfur containing gases from the crude oil stream. Furthermore, the addition of a polyalkylamine to the stirred crude oil can also greatly assist in the expulsion of sulfur containing gases. After processing under these conditions, the hydrogen sulfide producing capacity of the crude oil is reduced significantly, thus making the crude safer for transportation and handling by reducing the health and environmental risks.

Abstract: A process for treating a light cracked naphtha to be used as an etherification feed stock is disclosed in which mercaptans, H2S and diolefins are removed simultaneously in a distillation column reactor using a reduced nickel catalyst. The mercaptans and H2S are reacted with the diolefins to form sulfides which are higher boiling than that portion of the naphtha which is used as feed to the etherification unit. The higher boiling sulfides are removed as bottoms along with any C6 and heavier materials. Any diolefins not converted to sulfides are selectively hydrogenated to mono-olefins for use in the etherification process.

Abstract: A process for concurrently fractionating and hydrotreating of a full range naphtha stream. The full boiling range naphtha stream is subjected to simultaneous hydrodesulfurization and splitting into a light boiling range naphtha and a heavy boiling range naphtha, which have been treated to covert mercaptans in the fractions to H2S, which is separated with and separated from the light naphtha wherein the improvement is a further hydrodesulfurization by contacting the light boiling range naphtha with hydrogen in countercurrent flow in a fixed bed of hydrodesulfurization catalyst to remove recombinant mercaptans which are formed by the reverse reaction of H2S with olefins in the naphtha during the initial hydrodesulfurization.

Abstract: The desulfurization of petroleum distillates can be carried out by cyclic low-temperature adsorption of oxidized sulfur compounds with activated carbon followed by regeneration of the activated carbon using an organic solvent. The activated carbon used in the process is commercially available and its surface area that ranges from approximately 500 to 2000 m2/g having a substantial portion of its pores in the range between 10 to 100 Angstroms.

Abstract: A novel liquid collector assembly has been developed for a reactor used in the sweetening of sour hydrocarbons (e.g. sour gasoline). This refinery process normally involves contacting a reaction liquid, comprising both aqueous (caustic solution) and organic (hydrocarbon) phases, with a fixed bed of oxidation catalyst. The collector assembly design, comprising a piping manifold and a plurality of dependent, vertically aligned, and perforated conduits, allows for improved separation of the reaction products into essentially pure treated hydrocarbon and spent alkaline reagent streams. If sodium hydroxide is used as caustic solution, for example, the treated hydrocarbon product will normally contain less than 1 ppm by weight of sodium.

Abstract: A process for treating a light cracked naphtha to be used as an etherification feed stock is disclosed in which mercaptans, H2S and diolefins are removed simultaneously in a distillation column reactor using a reduced nickel catalyst. The mercaptans and H2S are reacted with the diolefins to form sulfides which are higher boiling than that portion of the naphtha which is used as feed to the etherification unit. The higher boiling sulfides are removed as bottoms along with any C6 and heavier materials. Any diolefins not converted to sulfides are selectively hydrogenated to mono-olefins for use in the etherification process.

Abstract: A process and apparatus for treating raw gasoline from catalytic cracking to obtain gasoline with the qualities required for use as motor fuel comprises selective hydrogenation followed by stabilization and optional cooling of the effluent, then sweetening followed by degassing to obtain a dedienized, stabilized and sweetened gasoline. The hydrogenation catalyst preferably comprises 0.1-1% of palladium deposited on a support, sweetening is preferably carried out on a solid catalyst containing an aluminosilicate of an alkali metal (for example sodalite), a metal chelate and activated charcoal. The product from this process can be placed directly in the gasoline pool or, advantageously, fractionated to obtain one or more cuts which can be used as feeds for etherification.

Abstract: A process for recovering a base oil of lubricating viscosity from used oil in which, following optional pretreatment, used oil is re-refined by distilling it in distillation apparatus having multiple theoretical plates. Impurities are then extracted from the lube range distillate fraction or fractions with a liquid extractant such as N-Methyl-2-Pyrrolidone (NMP) at a temperature below the temperature, if any, of complete miscibility of the extractant and the oil. The oil and extractant are then separated whereupon the extractant is re-used in the process and the oil is subject to further treatment, as necessary, for targeted uses.

Abstract: A process for removing essentially naphthenic acids from a crude oil which has not previously been fractionated by distillation, or from which only a naphtha fraction has been distilled. The crude oil is hydrogenated at 1-50 bars and 100-300.degree. C. over a catalyst of the kind used for hydrogenation of atmospheric residue oils. As a catalyst, especially Ni--Mo or Ni--Co deposited on alumina as a carrier material is used.

Abstract: A method for scavenging mercaptans in a hydrocarbon fluid is disclosed. According to the method, an effective mercaptan-scavenging amount of an aqueous scavenging composition is added to the fluid. The composition comprises a quaternary ammonium hydroxide of the formula R.sup.1 R.sup.2 R.sup.3 R.sup.4 NOH. R.sup.1 and R.sup.2 are, independently, alkyl groups of from one to about eighteen carbon atoms, aryl groups of from six to about eighteen carbon atoms or alkylaryl groups of from seven to about eighteen carbon atoms. R.sup.3 is an alkyl group of from two to about eighteen carbon atoms, an aryl group of from two to about eighteen carbon atoms or an alkylaryl group of from four to about eighteen carbon atoms. R.sup.2 and R.sup.3 may be joined to form a heterocyclic ring including the N and optionally an oxygen atom. R.sup.4 is --(CH.sub.2 CH.sub.2 O).sub.n H, wherein n is an integer from one to about eighteen, or --CHR.sup.5 CHR.sup.6 Y, wherein R.sup.5 and R.sup.

Abstract: Sulfur-containing carbonaceous materials are desulfurized by reaction with a mixture of an oxidizing agent and a carbonyl compound under alkaline conditions at a temperature ranging from ambient temperature to about 250.degree. F. and a pressure of about 1 atmosphere to 2 atmospheres. The products of the reaction are a desulfurized carbonaceous material in which the sulfur content is less than about 1%, and gaseous sulfur compounds. The carbonyl compound can be recovered and reused.

Abstract: The invention comprises a method for reducing the amount of carboxylic acids in petroleum feeds comprising the steps of (a) adding to said petroleum feed a catalytic agent comprising an oil soluble or oil dispersible compound of a metal selected from the group consisting of Group VB, VIB, VIIB and VIII metals, wherein the amount of metal in said petroleum feed is at least about 5 wppm, (b) heating said petroleum feed with said catalytic agent in a reactor at a temperature of about 400 to about 800.degree. F. (about 204.44 to about 426.67.degree. C.) and a pressure of about atmospheric to about 1000 psig (about 6996.33 kPa) in the substantial absence of hydrogen, and (c) sweeping the reactor containing said petroleum feed and said catalytic agent with an inert gas to maintain the combined water and carbon dioxide partial pressure below about 50 psia (344.75 kPa).

Abstract: The invention comprises a method for reducing the amount of carboxylic acids in petroleum feeds comprising the steps of (a) adding to said petroleum feed a catalytic agent comprising an oil soluble or oil dispersible compound of a metal selected from the group consisting of Group VB, VIB, VIIB and VIII metals, wherein the amount of metal in said petroleum feed is at least about 5 wppm, (b) heating said petroleum feed with said catalytic agent in a reactor at a temperature of about 400 to about 800.degree. F. (about 204.44 to about 426.67.degree. C.), under a hydrogen pressure of 15 psig to 1000 psig (204.75 to 6996.33 kPa), and (c) sweeping the reactor containing said petroleum feed and said catalytic agent with hydrogen-containing gas at a rate sufficient to maintain the combined water and carbon dioxide partial pressure below about 50 psia (about 344.75 kPa).

Abstract: A process for selectively removing lower molecular weight naphthenic acids from an acidic crude by treating the crude with a small pore hydrotreating catalyst at temperatures of from about 200.degree. to 370.degree. C. Removing these lower molecular weight naphthenic acids reduces the corrosive nature of acidic crudes.

Abstract: A hydrocarbon stream containing sulfur and sulfur compounds is contacted with a water suspension of dolomitic lime and dibasic acid catalyst in a reaction vessel in order to transfer the sulfur and sulfur compounds from the petroleum vapor to the water phase. During sulfur removal, naphthenic acid present in the hot petroleum vapor is converted to a high quality naphtha fraction. In the water phase, the sulfur compounds react with the available alkalinity from the dolomitic lime and dibasic acid. The insoluble calcium or magnesium based reaction products can then be removed from the water phase through conventional solids concentrating and separating equipment.

Abstract: A method for scavenging mercaptans in a hydrocarbon fluid is disclosed. According to the method, an effective mercaptan-scavenging amount of an aqueous scavenging composition is added to the fluid. The composition comprises a quaternary ammonium hydroxide of the formula R.sup.1 R.sup.2 R.sup.3 R.sup.4 NOH. R.sup.1 and R.sup.2 are, independently, alkyl groups of from one to about eighteen carbon atoms, aryl groups of from six to about eighteen carbon atoms or alkylaryl groups of from seven to about eighteen carbon atoms. R.sup.3 is an alkyl group of from two to about eighteen carbon atoms, an aryl group of from two to about eighteen carbon atoms or an alkylaryl group of from four to about eighteen carbon atoms. R.sup.2 and R.sup.3 may be joined to form a heterocyclic ring including the N and optionally an oxygen atom. R.sup.4 is --(CH.sub.2 CH.sub.2 O).sub.n H, wherein n is an integer from one to about eighteen, or --CHR.sup.5 CHR.sup.6 Y, wherein R.sup.5 and R.sup.

Abstract: A composition and a process for substantially reducing or removing sulfide from a sulfide-containing fluid are disclosed. The composition comprises, or is prepared by combining components comprising, a sulfide-containing fluid and a sulfide-scavenging amount of a sulfide scavenger selected from the group consisting of bromates, iodates, and combinations of two or more thereof. The process comprises contacting a sulfide-containing fluid with a sulfide-scavenging amount of a sulfide scavenger under a condition sufficient to substantially reduce the sulfide concentration in the fluid.

Abstract: The demercaptanization of petroleum distillates may be carried out by means of the oxidation of the mercaptans contained therein using the oxygen in the air, at a temperature of about 80.degree. to about 220.degree. C., in the presence of about 0.01 to about 10.0 mass % of a water-soluble salt of copper, iron, nickel, or cobalt, on a fibrous carbonaceous material in the form of a woven fabric, felt, rope, or twisted strand, used as a heterogeneous catalyst. The fibrous carbonaceous material used in the process contains oxides of calcium, magnesium, copper, manganese, iron, zinc, and aluminum in an amount of up to about 0.03 mass %.

Abstract: Sweetening of sour hydrocarbon feedstocks by contacting with an aqueous solution of a metal chelate as an oxidation catalyst in the presence of oxygen is hindered by the difficulty of recovering metal chelate. Extraction of the aqueous phase with a liquid secondary amine with low water solubility removes a main portion of the metal chelate, usually a mixture of polysulfonated cobalt phthalocyanines, from the aqueous phase, and subsequent recovery of the chelate from the amine extract enables a viable alternative to feed bed processes.

Abstract: A catalytic mixture of discrete solid materials and a mercaptan oxidation process for using the catalytic mixture have been developed. The catalytic mixture comprises a metal chelate dispersed on a non-basic solid support and a solid base. The process involves contacting a sour middle distillate hydrocarbon fraction which contains mercaptans with the supported metal chelate and the solid base mixture in the presence of an oxidizing agent and a polar compound. The process is unique in that both the catalyst and the base are discrete solid materials.

Abstract: A process for sweetening a petroleum cut containing mercaptans, wherein said petroleum cut is subjected to oxidation conditions by being contacted with a porous catalyst, in the presence of air said process being characterised in that said catalyst comprises 10 to 98% by weight of at least one mineral solid phase constituted of an alkaline aluminosilicate with a Si/Al atomic ratio less than or equal to 5, 1 to 60% by weight of active carbon, 0.02 to 2% by weight of at least one metal chelate and 0 to 20% by weight of at least one organic or mineral binding agent, has a basicity determined according to the 2896 ASTM standard with 20 milligrams of potash per gram and a total BET surface area of 10 m.sup.2 g.sup.-1, and contains inside its pore structure a permanent aqueous phase representing 0.1 to 40% by weight of dry catalyst.

Abstract: The present invention provides a method for scavenging H.sub.2 S from aqueous and hydrocarbon substrates using an epoxide. Preferred epoxides are styrene oxide, 1,3-butadiene diepoxide, and cyclohexene oxide.

Abstract: A process for hydrotreating a hydrocarbon feedstock, such as light cycle oil, using a catalyst composition containing a hydrogenation/dehydrogenation component and an acidic solid component including a Group IVB metal oxide modified with an oxyanion of a Group VIB metal. The hydrotreating process removes contaminants, such as sulfur and/or nitrogen, from the feedstock.

Abstract: A catalytic system of physically separate and discrete solid materials and a mercaptan oxidation process for using the catalytic system have been developed. The catalytic system comprises a supported metal chelate dispersed on a non-basic solid support and a solid base. The process involves contacting a sour middle distillate hydrocarbon fraction which contains mercaptans first with the solid base and then, in the presence of an oxidizing agent and a polar compound, with the supported metal chelate. The process is unique in that both the catalyst and the base are solid materials and that the solid base is in a separate fixed bed from the supported metal chelate.

Abstract: Contaminants such as mercaptans, oxygenates and olefins are removed from paraffin-rich feed streams through the use of catalytic distillation performed using an acid catalyst such as a sulphonated resin in the substantial absence of hydrogen. The mercaptans are reacted with the olefins to form less volatile thioethers removed as part of a net bottoms stream with the treated paraffins being removed as the overhead stream.

Abstract: A catalytic mixture of discrete solid materials and a mercaptan oxidation process for using the catalytic mixture have been developed. The catalytic mixture comprises a metal chelate dispersed on a non-basic solid support and a solid base. The process involves contacting a sour middle distillate hydrocarbon fraction which contains mercaptans with the supported metal chelate and the solid base mixture in the presence of an oxidizing agent and a polar compound. The process is unique in that both the catalyst and the base are discrete solid materials.

Abstract: A catalytic system of physically separate and discrete solid materials and a mercaptan oxidation process for using the catalytic system have been developed. The catalytic system comprises a supported metal chelate dispersed on a non-basic solid support and a solid base. The process involves contacting a sour middle distillate hydrocarbon fraction which contains mercaptans first with the solid base and then, in the presence of an oxidizing agent and a polar compound, with the supported metal chelate. The process is unique in that both the catalyst and the base are solid materials and that the solid base is in a separate fixed bed from the supported metal chelate.

Abstract: A catalyst and a process for using the catalyst have been developed. The catalyst is a metal chelate dispersed on a basic support which is a combination of a solid base and a secondary component. The solid base can be a solid solution of metal oxides and/or a layered double hydroxide (LDH) and the secondary component can be calcium oxide, magnesium oxide, calcium hydroxide and magnesium hydroxide. The process involves contacting a sour hydrocarbon fraction which contains mercaptans with the catalyst in the presence of an oxidizing agent and a polar compound. Examples of these polar compounds are water and alcohols, with methanol being especially preferred. The process is unique in that the solid solution or LDH are solid bases which eliminates the need for a liquid base. Optionally, an onium compound may be used as a catalyst promoter.

Abstract: A process for the fixed-bed sweetening of sour petroleum distillates with fraction temperatures of from about 125.degree. to about 350.degree. C. and having an acid number of 0.03 mg of KOH/g or higher. The reduction of the acidity and the oxidation of the mercaptans necessary for the sweetening of the distillates are carried out together in a single stage by passing the distillate, in the presence of an oxidizing agent but in the absence of a basic solution, and particularly of an alkali-metal hydroxide solution, over an oxidation catalyst whose specific surface ranges from 1 to 10 m.sup.2 /gram, and preferably from 2 to 6 m.sup.2 /gram, and whose micropore volume ranges from 0.01 to 0.10 cm.sup.3 /gram, and preferably from 0.02 to 0.05 cm.sup.3 /gram.

Abstract: Sour sulfhydryl group containing oils are treated with an effective amount of a sweetening, hydrogen sulfide vapor reducing quaternary ammonium compound of the formula ##STR1## (a) wherein (i) R.sup.1, R.sup.2 and R.sup.3 are hydrocarbon groups including alkyl, aryl, alkaryl or arylalkyl groups, of up to 24 carbon atoms, and if an alkyl group, may include a cycloalkyl; with the proviso that two of R.sup.1, R.sup.2 and R.sup.3 may be in saturated heterocyclic ring which includes said nitrogen atom and may also include an oxygen atom; and (ii) at least one of R.sup.1, R.sup.2 and R.sup.3 has two or more carbon atoms; and (b) wherein R.sup.4, R.sup.5, R.sup.6 and R.sup.7 independently are hydrogen or a hydrocarbon group of up to six carbon atoms, with the proviso that two of R.sup.4, R.sup.5, R.sup.6 and R.sup.7 may be in a cycloalkane ring. The compounds used in this treatment are especially suitable for high boiling, heavy residual fuels under low mix conditions.

Abstract: A process for treating a hydrocarbon fraction which contains mercaptans has been developed. The process uses a novel catalyst which is composed of a metal chelate dispersed on a basic support which is either a solid solution of metal oxides or a layered double hydroxide (LDH). In the process the hydrocarbon fraction is contacted with the catalyst in the presence of an oxidizing agent and a polar compound. Examples of these polar compounds are water and alcohols, with methanol being especially preferred. The process is unique in that the solid solution or LDH are solid bases which eliminates the need for a liquid base. Optionally, an onium compound may be used as a catalyst promoter.

Abstract: This invention relates to a process for improving the activity of a catalyst effective in sweetening a hydrocarbon fraction containing mercaptans. The process involves adding to the hydrocarbon fraction an effective amount of an aqueous solution comprising ammonium hydroxide, a metal chelate and an onium compound.

Abstract: Hydrogen sulfide evolution in a heavy hydrocarbon (such as a residual fuel oil) derived from a heavy crude oil (such as a API 8 gravity crude) is suppressed by contacting the hydrocarbon with a compound corresponding to the reaction product of a heterocyclic aldehyde (such as furfural) and an organic primary amine.

Abstract: A method for scavenging hydrogen sulfide in an aqueous and/or hydrocarbon medium is disclosed. According to the method, the medium is contacted with an effective amount of an amidine selected from the group consisting of monoamidines of from 1 to about 18 carbon atoms and polyamidines comprising from 2 to 3 amidine groups of from 1 to about 18 carbon atoms per amidine group.

Abstract: Sour sulfhydryl-group containing oils are treated with an amount of hexamethylenetetramine effective to sweeten the oil and reduce headspace H.sub.2 S to a desired level.

Abstract: Process and apparatus for continuous production of disulfides by reacting at least one mercaptan and oxygen in the presence of a suitable catalyst selected from the group consisting of an alkaline earth metal oxide alone or in combination with an alkali metal oxide, on a refractory support, or a basic form of macroreticular polystyrene-divinyl benzene copolymer.

Abstract: Sour sulfhydryl group containing oils and gases are treated with an effective amount of a sweetening, hydrogen sulfide quantity reducing aminocarbinol of the formulaR.sub.2 N--CH(--R.sup.1)OHwherein R.sup.1 is hydrogen or a hydrocarbyl or inertly substituted hydrocarbyl and each R is independently hydrocarbyl or inertly substituted hydrocarbyl or both R groups are collectively a divalent hydrocarbon or ether radical combined with the nitrogen of the aminocarbinol to form a heterocyclic ring represented by the formula(--R--R--)>N--CH(--R.sup.1)OH.The aminocarbinols used in this treatment are especially suitable for sour gases and high boiling, heavy residual fuels under low mix conditions.

Abstract: This invention relates to a liquid-liquid process for treating a sour hydrocarbon fraction. The process comprises contacting the hydrocarbon fraction in the presence of an oxidizing agent with an aqueous solution containing ammonium hydroxide, a metal chelate and an onium compound selected from the group consisting of quaternary ammonium, phosphonium, arsonium, stibonium, oxonium and sulfonium compounds. A preferred onium compound is a quaternary ammonium compound with an especially preferred compound being a quaternary ammonium halide.