Abstract: A part of the hydrogen sulphide content of a feed gas stream comprising hydrogen sulphide is burned by a burner that fires into a furnace. The combustion is supported by a stream of oxygen or oxygen-enriched air. Resulting sulphur dioxide reacts with residual hydrogen sulphide in the furnace to form sulphur vapor. Sulphur is condensed out of the resulting gas mixture in a sulphur condenser. At least part of the sulphur-free gas mixture flows through a reactor in which its sulphur dioxide content is reduced to hydrogen sulphide. Water vapor is removed from the resulting gas stream in a water condenser. At least part of the gas stream now essentially free of water vapor is recycled to the furnace. A purge stream is taken either from immediately downstream of the sulphur condenser or from intermediate the water condenser and the furnace, or from the furnace and, if desired, subjected to further treatment to remove sulphur-containing gases therefrom.

Abstract: For the thermal conversion of hydrogen sulfide contained in a gaseous stream, the gaseous stream is introduced into a non-catalytic reactor together with sulfur dioxide obtained from a waste gas purification facility arranged downstream of the reactor. If necessary, the sulfur yield can be regulated by feeding additional fuel gas and/or reducing gas and/or process air into the reactor. The thus-produced vapor-phase sulfur is condensed out by cooling and is obtained as a product; the resultant gaseous stream extensively freed of sulfur compounds is discharged and fed into the aforesaid downstream waste gas purification facility.

Abstract: Hydrogen sulfide or other gaseous component is removed from a gas stream containing the same by distribution of the gas stream in the form of fine bubbles by a rotary impeller and stationary shroud arrangement at a submerged location in an aqueous iron or other transition metal chelate solution, or other suitable catalyst, contained in an enclosed reaction vessel. Sulfur particles, or other insoluble phase product, of narrow particle size range formed in the reaction are floated off from the iron chelate solution. An oxygen-containing gas stream also is distributed in the form of fine bubbles by a separate rotary impeller and stationary shroud arrangement at a separate submerged location in the iron chelate solution. The second submerged location generally is separated from the first by a baffle extending downwardly in the reaction vessel from a top closure towards a bottom closure.

Abstract: A foul gas containing H.sub.2 S is brought into the presence of SO.sub.2 in a first stage to permit the reaction between SO.sub.2 and H.sub.2 S to form water and elemental sulfur. The SO.sub.2 is solubilized in an absorbent composition which includes a solvent for both SO.sub.2 and H.sub.2 S so that the H.sub.2 S in the foul gas is first solubilized in the absorbent composition where it is then brought into contact with the solubilized SO.sub.2 for reaction between a major portion of the H.sub.2 S and the solubilized SO.sub.2 to form elemental sulfur. The gas is then passed to a second stage where any remaining H.sub.2 S is removed by aqueous catalytic reaction of the type conventional in the prior art. The apparatus utilized to carry out the present invention preferably includes a two stage column in which the first stage provides the absorbent material containing solubilized SO.sub.2 for reaction with the H.sub.2 S of the foul gas. During the SO.sub.2 extraction stage the major portion of the H.sub.

Abstract: Hydrogen sulfide is removed from natural gas by contacting the natural gas with a scrubber oil that absorbs the hydrogen sulfide. The natural gas typically contains some water, or water can be added, and the resulting mixture is used to form a water-in-scrubber oil emulsion. Sulfur dioxide added to the water-in-oil emulsion reacts with the hydrogen sulfide present in the emulsion.

Abstract: The present invention provides an improved coextruded medical grade port tubing. The medical grade port tubing provides characteristics that are desirable in the medical industry and therefore can be used as a medical port tubing in, for example, renal therapy or blood donor tubes. To this end, the present invention provides a non-PVC coextruded medical grade port tubing including: an outer layer comprising a blend of polypropylene copolymer and styrene-ethylene-butylene-styrene copolymer; a tie layer; and a core layer including a blend of polyamide and ethylene vinyl acetate.

Abstract: Improved processes are disclosed for the removal of hydrogen sulfide from feed streams by conversion of hydrogen sulfide and sulfur dioxide to elemental sulfur and water, e.g. Claus process. The feed stream of the present invention is divided into two split streams wherein one is incinerated to form sulfur dioxide in the presence of oxygen. The sulfur dioxide is then separated from the water, nitrogen and other impurities and combined with the other split stream to form a reactor feed which is passed to a sulfur reaction zone for conversion to elemental sulfur. Due to the rejection of water, nitrogen and other impurities from the reactor inlet stream, a higher concentration of hydrogen sulfide and sulfur dioxide can be achieved in the sulfur reaction zone. As a result, the processes of the present invention can be used to increase the throughput of existing Claus process plants and reduce the size of new Claus process plants.

Abstract: Method and system for recovering sulfur from an ammonia acid gas stream containing hydrogen sulfide comprising the steps of combusting the ammonia acid gas stream with air or oxygen to convert the ammonia and the hydrogen sulfide therein to N.sub.2 and SO.sub.x, respectively, and thus form a nitrogen and sulfur oxide enriched gas stream. The nitrogen and sulfur oxide enriched gas stream is contacted with a solid absorbent bed to extract the sulfur oxides and retain them as sulfur compounds, thus forming a nitrogen bearing stream. The absorbent bed is then contacted with a hydrogen and/or hydrocarbon bearing stream to reduce the retained sulfur compounds to hydrogen sulfide and/or sulfur dioxide and thereby form a hydrogen sulfide and/or sulfur dioxide bearing stream. Sulfur is recovered from the hydrogen sulfide and/or sulfur dioxide bearing stream. The nitrogen bearing stream is sent to an incinerator or vented through a stack.

Abstract: The gas to be treated contains H.sub.2 S and carbon compounds first enters the combustion chamber of a Claus process plant and a gas mixture which contains 1 to 3 moles H.sub.2 S per mole of SO.sub.2 is withdrawn from that combustion chamber. The gas mixture is reacted in part to form elemental sulfur in at least one catalytic Claus process stage at temperatures above the dew-point temperature of the sulfur. The elemental sulfur is condensed in and removed from a sulfur cooler. An exhaust gas which contains 0.5 to 5% by volume H.sub.2 S and also contains COS, CS.sub.2 and H.sub.2 O is withdrawn from the last sulfur cooler of the Claus process plant. Oxygen is admixed with that exhaust gas, which is heated to a temperature of at least 200.degree. C. and is contacted with a catalyst, which comprises at least 80% by weight TiO.sub.2. The resulting elemental sulfur is condensed and withdrawn. The gas is subsequently contacted at temperatures of 120.degree. to 160.degree. C.

Abstract: A gaseous mixture containing chlorine, carbon dioxide and non-condensable gas is compressed and cooled to separate it into a residual gas formed principally of a major portion of the non-condensable gas and a condensate formed primarily of chlorine. The condensate is fed to a stripping column to desorb carbon dioxide and a minor portion of the non-condensable gas dissolved in the condensate. The stripped gas formed primarily of chlorine and carbon dioxide may be treated further. Namely, the stripped gas is mixed with the residual gas. At least a portion of the mixed gas is fed into an absorption column, whereby a major portion of remaining chlorine is absorbed to lower the chlorine content Removal of chlorine from such a gaseous mixture or an off-gas from the above process can be achieved by washing it with an aqueous solution or suspension containing an alkali metal sulfite and/or an alkaline earth metal sulfite while controlling the pH of the solution or suspension within a range of 1.9-6.3.

Abstract: The invention is a process wherein SO.sub.2 is absorbed in a concentrated solution of potassium citrate and the solution is reacted with H.sub.2 S at a temperature above the melting point of sulfur to form elemental sulfur. The reaction produces a solution lean in sulfur dioxide. SO.sub.2, in the form of a rich solution or a gas, can be introduced into the lean solution in order to inhibit post-formation of sulfur. This introduction of SO.sub.2 avoids a tendency for sulfur to form continually after the solution exits the reaction zone.

Abstract: A process of removing hydrogen sulfide from a gas stream in which the hydrogen sulfide is dissolved in an absorption zone by a solvent having a good solvent power for hydrogen sulfide and a much greater solvent power for sulfur dioxide. The resultant solution is divided into a major stream and a minor stream. The major stream is contacted with a small excess of sulfur dioxide over that required for reaction with hydrogen sulfide. Most of this solution is recycled to the absorption zone. The minor stream withdrawn from the absorption zone is mixed with the solution formed in the reaction zone which is not recycled, the proportion being such that there remains a small excess of hydrogen sulfide in solution. This solution is then stripped of hydrogen sulfide. By this means only a small fraction of the solution has to be stripped. Preferred solvents are those which promote the reaction of hydrogen sulfide with sulfur dioxide.

Abstract: Geothermal steam is condensed with a sulfite solution to abate hydrogen sulfide. A portion of the hydrogen sulfide is converted in the condensation in the presence of soluble cationic polymeric catalysts to soluble sulfur compounds while avoiding elemental sulfur and carbonate formation. The remainder of the hydrogen sulfide is incinerated and the sulfur dioxide in the incinerator effluent is absorbed in an alkaline solution to form the sulfites for the geothermal steam condensation. By maintaining stoichiometric ratios, the hydrogen sulfide is substantially converted to soluble thiosulfate without the use of chelates, peroxides or makeup sulfites.

Abstract: Process of treating sulfur containing gas streams by the Claus reaction in which a recycle stream containing a reactive component is employed in a negative feedback mode to maintain the sulfur producing Claus reaction at approximately equilibrium conditions. The feedstream may contain hydrogen sulfide or sulfur dioxide in a minor amount in an inert gas background. In one embodiment the feedstream to the reaction zone contains a stoichiometrically excess amount of sulfur dioxide for the Claus reaction. Effluent from the reaction zone is passed to a hydrogenation zone where the sulfur dioxide is converted to hydrogen sulfide. Hydrogen sulfide is extracted from the hydrogenation zone effluent and recycled to the Claus reaction zone. In another embodiment the feedsteam may contain a stoichiometrically excess amount of hydrogen sulfide.

Abstract: The invention relates to a method for cleaning exhaust gases weak in sulphur dioxide, or sulphur dioxide and hydrogen sulphide. In order to remove the sulphur content of an exhaust gas, the exhaust gas is absorbed into a solution containing sulphide. Thereafter into the solution is added an agent which causes any unstable compounds of sulphur and oxygen, such as thiosulphate and polythionates, which are formed in the scrubbing solution, to decompose into elemental sulphur and sulphate in the autoclave whereinto the scrubbing solution is fed. The pH of the solution emerging from the autoclave is adjusted to stay within the range 2.0-2.9.

Abstract: Adding sodium sulfite in the slurry of the iron oxide slurry process for scavenging hydrogen sulfide described in U.S. Pat. No. 4,246,244, eliminates excessive foaming on start-up, stabilizes the suspension of the oxide particles in the slurry, lessens clogging of reacted particles, which otherwise interferes with cleaning out the reactor vessel, and so materially buffers the slurry as to minimize corrosion of the reactor vessel and piping. Further, adding small amounts of oxygen to the gas stream, which would be expected to cause corrosion, does not do so; instead it prolongs the usefulness of the reactant oxide particles and affords increased acid-stability to the reaction products.

Abstract: A composition suitable for scavenging oxygen from aqueous systems, for example those used in well drilling, is provided which comprises a mixture of an oxygen-reactive sulfite and/or bisulfite (sulfite component) and an amount of iron oxide particles sufficient to catalyze the reaction between oxygen and the sulfite component. These particles have certain properties as further described herein. These compositions also serve as corrosion inhibitors in aqueous systems, such as drilling muds, to protect steel components from corrosion. A method is also provided for using such compositions in aqueous systems to scavenge oxygen from such systems, and also H.sub.2 S, if present.

Abstract: A process for the removal of H.sub.2 S from a fluid stream whereby the H.sub.2 S is converted to soluble sulfur compounds by treatment with a solution of ferric chelates containing an oxidizing agent and a water soluble cationic polymeric catalyst such as poly(dimethyldiallyl ammonium chloride).

Abstract: The present invention relates to the preparation of mixtures of sterically hindered substituted N-secondary amino acids or their alkali metal salts by a one-step reductive condensation of an amino acid or its alkali metal salt containing a primary amino group and a ketone to thereby form a mono-substituted amino acid or alkali metal salt thereof, followed by preparing the corresponding sterically hindered tertiary amino acids or alkali metal salt thereof by reacting the mono-substituted amino acids or alkali metal salt thereof with an unhindered aldehyde under reducing conditions in the presence of a hydrogenating catalyst. The novel mixtures of the sterically hindered mono-substituted amino acids and the tertiary amino acids and their alkali metal salts are useful promoters for alkaline salts in "hot pot" acid gas scrubbing processes.

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: The ammonia contained in ammonia- and hydrogen sulfide-containing gas mixtures is selectively removed through a gas washing with an aqueous ammonium sulfite-bisulfite solution, and recovered from the wash solution as a concentrated aqueous solution. For this purpose the coke oven crude gas is washed with an ammonium sulfite-bisulfite solution led in circulation, the surface tension of which amounts to below 80.times.10.sup.-5 N/cm, then the ammonia gas is driven away from the wash solution enriched with ammonia, e.g. by means of steam, and the released ammonia is recovered e.g. as aqueous ammonium solution through condensation of the vapor. The gas mixture is preferably purified or unpurified coke oven crude gas. In order to reduce the surface tension of the wash solution, alkyl sulfate, alkylamine, pyridine base, phenol or homologs thereof are added as surface active substance. The wash circulation is performed at between 15.degree. and 32.degree. C.

Abstract: In a process of decreasing the sulfur content of exhaust gases obtained during the recovery of sulfur from acid gases containing H.sub.2 S and other S-containing compounds in the Claus process, the acid gases which contain H.sub.2 S and other S-containing compounds are reacted in a Claus plant to form elemental sulfur. A gas which contains H.sub.2 S or SO.sub.2 is subsequently added at a controlled rate to maintain a stoichiometric ratio of 2:1 of H.sub.2 S to SO.sub.2 in the tail gas from the Claus plant. The gas which contains H.sub.2 S or SO.sub.2 may be added to the tail gas from the Claus plant or before the last contacting stage of a multistage Claus plant. During the addition of a gas which contains H.sub.2 S, the Claus plant can be operated at an H.sub.2 S to SO.sub.2 ratio of or below 2:1. During the addition of a gas which contains SO.sub.2 the Claus plant can be operated at an H.sub.2 S to SO.sub.2 ratio of or above 2:1. The H.sub.2 S and SO.sub.

Abstract: At least one of sulfur dioxide and a gaseous hydrosulfide is contacted with at least one of a sulfur-containing salt and a gaseous basic nitrogen compound to produce a solid, sulfur-containing composition.

Abstract: Process for removing gaseous impurities such as CO.sub.2, H.sub.2 S, HCN and SO.sub.2 from a gaseous mixture containing the same, comprising an absorption step in which the gaseous impurities are removed by a scrubbing solution, and a regeneration step in which the exhausted solution is submitted to stripping to remove the inpurities. The regenerated solution is treated with a flow of inert gases to improve the degree of regeneration and extract heat from said solution. The flow of inert gases, containing steam and desorbed impurities, is further enriched in steam supplied from the exterior and the resulting mixture is used as stripping means in the regeneration step.

Abstract: A method of purifying a hydrogenated gas containing carbon monoxide and hydrogen sulphide, for example a gaseous mixture obtained by partial oxidation of hydrocarbons, has a hydrogen sulphide elimination step which comprises a reaction between sulphur dioxide and hydrogen sulphide to form sulphur, the reaction being carried out in a solvent for sulphur dioxide and hydrogen sulphide.

Abstract: Improvements in the elimination and recovery of gaseous acid impurities from a gaseous mixture containing them, by an absorbing step, wherein said gaseous mixture is brought into contact with an alkaline absorbing solution and a regeneration step wherein the exhausted absorbing solution is regenerated by steam stripping, said absorption step comprising a main column and a secondary column, the main column operating at a higher pressure and by means of a supply of outside heat, the secondary column operating at a lower pressure and substantially by means of the steam obtained by expansion of the solution regenerated in the main column. The exhausted solution to be regenerated is conveyed firstly in one of the two regeneration columns wherein it is regenerated in an incomplete way, and subsequently into the other column where its regeneration is completed.

Abstract: Hydrogen sulfide in a gas is converted to sulfur by treatment with sulfur dioxide in the presence of a buffered organic polybasic acid with conversion of excess sulfur compounds in the gas to sulfur dioxide for recycle to the conversion.

Abstract: In the process disclosed, gas from a coke plant is washed with an aqueous metallic salt solution including sulfureous and sulfuric acid to absorb the ammonia, hydrogen sulfide and hydrogen cyanide from the gas. The washing solution is then oxidized in an aerating tank to recover elementary sulfur. A portion of the washing fluid from the oxidizer is returned for continued washing of gas and a portion of the fluid is heated in the presence of a catalyst to yield products of combustion including an acid anhydride and a metal or metal oxide. After processing the combustion products through a heat recovering system, the acid anhydride and metal oxides are combined and react to form renewed aqueous metal salt solution that is combined with the oxidized washing solution to wash additional quantities of gas.

Abstract: A process for regenerating absorbent solutions used for removing gaseous impurities such as CO.sub.2, H.sub.2 S,HCN, SO.sub.2 and other acidic gases from gaseous mixtures by stripping with steam, which comprisesA. dividing the solution to be regenerated into a principal and a secondary fraction (p and s) and regenerating these fractions separately from each other in a principal and a secondary regeneration column (P and S), the principal regeneration column being operated at a pressure of at least about 0.2 to 0.5 atm above the pressure of the secondary regeneration column,B. regenerating the principal fraction in the principal regeneration column by heat which is fed from outside into the lower part of the column,C. regenerating the secondary fraction in the secondary regeneration column by heat which has been removed from the regenerated solution leaving the principal regeneration column andD. passing the regenerated fractions to the absorber.

Abstract: Ammonia, hydrogen cyanide and hydrogen sulfide contained in gas streams are separated from the gas streams by contacting the gas stream with an aqueous solution containing free oxygen for a time sufficient for the ammonia, hydrogen sulfide and hydrogen cyanide to react with the oxygen present to form ammonium thiocyanate and water for further treatment or disposal.One method of treatment is to thermally and catalytically convert for the ammonium thiocyanate to ammonia or nitrogen and hydrogen sulfide in the form of a second gas stream which is processed for recovery of any formed ammonia and the hydrogen sulfide.

Abstract: A desulfurizing process wherein a gas stream containing SO.sub.2 is contacted with a citric acid or citrate-containing solution, and a gas stream containing H.sub.2 S is contacted with the resulting solution, whereby elemental sulfur is precipitated and removed. The rate of flow of the respective gases contacting the aforesaid solution is such that the amount of H.sub.2 S and SO.sub.2 contained in the solution after said solution has been contacted with the gas streams is substantially in the ratio of two mols of H.sub.2 S to one mol of SO.sub.2. A portion at least of the solution from which elemental sulfur is removed is passed to the first step of the process, for contacting the gas stream containing SO.sub.2.