Utilizing Organic Reactant Patents (Class 423/226)
  • Patent number: 4808386
    Abstract: A process for the simultaneous partial oxidation and desulfurization of an ash-containing solid carbonaceous fuel comprising (basis solid fuel) 0.2 to 8.0 wt. % sulfur and 0.1 to 30 wt. % of silicate compounds for the production of gaseous mixtures comprising H.sub.2 and CO and entrained molten slag. In the process, the solid carbonaceous fuel and supplemental iron-containing material are reacted by partial oxidation in the reaction zone of a free-flow unobstructed down-flowing vertical refractory lined gas generator with a controlled amount free-oxygen containing gas and a temperature moderator so that an equilibrium oxygen concentration is provided in the gas phase in the reaction zone having a partial pressure which is less than about 10.sup.-7 atmospheres. The partial oxidation and desulfurization reactions take place simultaneously at a temperature which is above 1900.degree. F. and about 10.degree. to 200.degree. F. above the fluid temperature of the slag at an increased thermal efficiency.
    Type: Grant
    Filed: September 24, 1987
    Date of Patent: February 28, 1989
    Assignee: Texaco Inc.
    Inventors: Mitri S. Najjar, Roger J. Corbeels
  • Patent number: 4808385
    Abstract: The present invention relates to a cyclic continuous process and a composition for the removal of hydrogen sulfide from a variety of sour gas streams. The sour gas stream is contacted with an aqueous solution of a water-soluble organic polymeric chelate containing an oxidizing polyvalent metal, e.g., Fe(III). The sulfur in the hydrogen sulfide is converted to elemental sulfur and the iron in the polymeric chelate is reduced. The process includes removal of the elemental sulfur, and an inexpensive method for removing water and excess low molecular weight materials, e.g., materials having molecular weights below 500, preferably using ultrafiltration or dialysis, regeneration and recycle of the reactive polyvalent metal.
    Type: Grant
    Filed: February 18, 1987
    Date of Patent: February 28, 1989
    Assignee: The Dow Chemical Company
    Inventor: Robert R. Grinstead
  • Patent number: 4789530
    Abstract: A process for the preferential absorption of H.sub.2 S from a gas which contains H.sub.2 S and CO.sub.2 comprises contacting of the gas with a sorbent solution comprising alkali metal ethylenediaminetetraacetate and/or alkali metal nitrilotriacetate, in the substantial absence of oxidizing agents which can oxidize H.sub.2 S.
    Type: Grant
    Filed: December 9, 1987
    Date of Patent: December 6, 1988
    Assignee: Phillips Petroleum Company
    Inventors: Marvin M. Johnson, Ted H. Cymbaluk, Gerhard P. Nowack
  • Patent number: 4784838
    Abstract: A cyclic process for removing H.sub.2 S from a gaseous stream comprising contacting the gaseous stream with a solution of a chelated polyvalent metal to produce elemental sulfur, removing the elemental sulfur, and regenerating the reaction solution, e.g., by contacting it with oxygen, and recycling the regenerated solution to the reaction zone, is modified by introducing into the solution a free chelating agent. The introduction of the free chelating agent eliminates the loss of the polyvalent metal and the chelated polyvalent metal from the reaction solution.There is also disclosed an aqueous reaction solution comprising a chelated polyvalent metal, sulfur, and a free chelating agent in the amount equal to at least about 0.1% by weight of the amount of the chelated polyvalent metal in the solution.
    Type: Grant
    Filed: April 26, 1988
    Date of Patent: November 15, 1988
    Assignee: Mobil Oil Corporation
    Inventors: James M. Paul, Earl S. Snavely, Jr.
  • Patent number: 4781901
    Abstract: A method of removing hydrogen sulfide and carbon dioxide from a sour gaseous stream in a contact zone by contacting the sour gaseous stream with a lean CO.sub.2 -selective absorbent in an aqueous alkaline solution containing a polyvalent metal chelate at a pH of about 7 to about 10 wherein the polyvalent metal chelate is in one embodiment of the invention in the reduced or lower valence state in a contact zone and is oxidized to the oxidized or higher valence state in an oxidation zone so as to convert hydrosulfide and/or sulfide salts present in the contact zone to sulfur. In a second embodiment, the aqueous alkaline solution and CO.sub.2 -selective absorbent in contact with the gaseous stream is a mixture containing a higher valence polyvalent metal chelate together with a lower valence polyvalent metal chelate.
    Type: Grant
    Filed: February 19, 1987
    Date of Patent: November 1, 1988
    Assignee: The Dow Chemical Company
    Inventor: Gaines C. Jeffrey
  • Patent number: 4775519
    Abstract: Improvement are provided in accordance with the present invention by a continuous process for the treating of a gas stream containing acid gas components wherein the gas stream is counter currently contacted in an absorption zone with an aqueous solution of a mixture of N-methyldiethanolamine with imidazole or a methyl substituted imidazole to thereby provide for acid gas (e.g., CO.sub.2) absorption.
    Type: Grant
    Filed: October 31, 1985
    Date of Patent: October 4, 1988
    Assignee: Texaco Inc.
    Inventor: Edward C. Yit Nieh
  • Patent number: 4761164
    Abstract: The present invention is a process for separating one or more components of a gas mixture. The process comprises passing the gas mixture over a membrane, which is selectively permeable to the component being separated, due to one or more reversible reactions between the component desired to be separated and a layer of active molten material immobilized in a suitable support material and/or encapsulated in a non-porous gas permeable polymer material.
    Type: Grant
    Filed: November 25, 1986
    Date of Patent: August 2, 1988
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Guido P. Pez, Richard T. Carlin, Daniel V. Laciak, James C. Sorensen
  • Patent number: 4758416
    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.
    Type: Grant
    Filed: December 30, 1986
    Date of Patent: July 19, 1988
    Assignee: Shell Oil Company
    Inventors: Howard L. Fong, David A. Van Kleeck, John M. Harryman
  • Patent number: 4749555
    Abstract: The invention here disclosed is a process for the selective removal of H.sub.2 S and COS from a gas stream having a relatively large concentration of CO.sub.2 and being predominantly formed of light hydrocarbons, such as methane. This process provides for the selective solvent extraction of H.sub.2 S and COS without absorbing CO.sub.2. In this process, the solvent comprises a bridgehead amine, a tertiary amine, water, and optionally a physical solvent acceptable to COS absorption, such as sulfolane. The absorption conditions of this process comprise a pressure of from about atmospheric to about 1200 psig and a temperature of from about 40.degree. F. to about 250.degree. F. The treated stream derived from this process contains CO.sub.2 and light hydrocarbons and a near absence of H.sub.2 S and COS.
    Type: Grant
    Filed: October 2, 1986
    Date of Patent: June 7, 1988
    Assignee: Shell Oil Company
    Inventor: Warren V. Bush
  • Patent number: 4741888
    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.
    Type: Grant
    Filed: December 30, 1986
    Date of Patent: May 3, 1988
    Assignee: Shell Oil Company
    Inventors: Howard L. Fong, David A. Van Kleeck, John M. Harryman
  • Patent number: 4729883
    Abstract: The invention relates to a process for the removal of acid gases from gaseous mixtures wherein said mixture is contacted with an aqueous alkaline solution comprising a compound of an alkali metal or ammonia and an alkanolamine-based promoter characterized in that the promoter is a mixture of at least one secondary alkanolamine and at least one N-alkyl-2-aminoethanol, said alkyl radical containing up to 3 carbon atoms.
    Type: Grant
    Filed: September 5, 1986
    Date of Patent: March 8, 1988
    Assignee: British Gas Corporation
    Inventors: Chi W. Lam, Terence J. Ritter, Peter Small
  • Patent number: 4705676
    Abstract: A process for removal of solid sulfur from specified solubilized iron chelate-containing solutions is described, the process being characterized by melting of the sulfur and maintenance of the solution during the melting and separation operations in the substantial absence of oxygen.
    Type: Grant
    Filed: August 23, 1985
    Date of Patent: November 10, 1987
    Assignee: Shell Oil Company
    Inventors: Howard L. Fong, Zaida Diaz, George C. Blytas
  • Patent number: 4696802
    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.
    Type: Grant
    Filed: November 27, 1985
    Date of Patent: September 29, 1987
    Assignee: The Dow Chemical Company
    Inventor: Stephen A. Bedell
  • Patent number: 4680127
    Abstract: The present invention is directed to methods of reducing the amount of hydrogen sulfide in hydrogen sulfide-containing aqueous or wet gaseous mediums without solids formation. This invention comprises adding an effective amount for the purpose of glyoxal or glyoxal in combination with formaldehyde or glutaraldehyde to the desired hydrogen sulfide-containing medium.
    Type: Grant
    Filed: December 13, 1985
    Date of Patent: July 14, 1987
    Assignee: Betz Laboratories, Inc.
    Inventor: James G. Edmondson
  • Patent number: 4664902
    Abstract: A process for removal of solid sulfur from specified solubilized iron chelate-containing solutions is described, the process being characterized by melting of the sulfur and maintenance of the solution during the melting and separation operations in the substantial absence of oxygen.
    Type: Grant
    Filed: August 23, 1985
    Date of Patent: May 12, 1987
    Assignee: Shell Oil Company
    Inventors: Howard L. Fong, Zaida Diaz, George C. Blytas
  • Patent number: 4654062
    Abstract: A process is set forth for the separation of carbon dioxide from propane and higher alkanes using a carbon dioxide-loaded lean oil solvent and higher solvent flows and heat utilizations rather than mechanical energy utilization. A high pressure carbon dioxide product is produced, making the invention valuable in carbon dioxide miscible flood enhanced petroleum recovery operations.
    Type: Grant
    Filed: July 11, 1986
    Date of Patent: March 31, 1987
    Assignee: Air Products and Chemicals, Inc.
    Inventor: Gerry N. Gottier
  • Patent number: 4649032
    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.
    Type: Grant
    Filed: January 11, 1985
    Date of Patent: March 10, 1987
    Assignee: Mobil Oil Corporation
    Inventors: Earl S. Snavely, Jr., Timothy A. Jones
  • Patent number: 4647397
    Abstract: Process and composition for removing H.sub.2 S and like sulfides from gas streams by contact with a substituted aromatic nitrile having an electron-attracting substituent on the aromatic ring at least as strong as halogen (e.g., isophthalonitrile) and an organic tertiary amine in an inert organic solvent such as N-methyl-2-pyrrolidone.
    Type: Grant
    Filed: April 29, 1985
    Date of Patent: March 3, 1987
    Assignee: Chevron Research Company
    Inventors: Robert Starkston, Mark C. Luce, Robert V. Homsy
  • Patent number: 4643886
    Abstract: A method for removing hydrogen sulfide from a gaseous stream by contacting the gaseous stream with a polyvalent metal chelate present in an aqueous alkaline scrubbing solution including the regeneration of the polyvalent metal chelate in an electrolytic cell and automatic control of the pH of said aqueous alkaline scrubbing solution at about 7 to 9.
    Type: Grant
    Filed: December 6, 1985
    Date of Patent: February 17, 1987
    Assignee: The Dow Chemical Company
    Inventors: Dane Chang, Stephen A. Bedell
  • Patent number: 4637926
    Abstract: Process for the absorption of hydrogen sulphide impurity from gases or liquid hydrocarbons comprising:(a) washing the gas or liquid hydrocarbon containing hydrogen sulphide with an aqueous alkaline solution of(a1) one or more compounds having the formula: ##STR1## or a water-soluble salt thereof, wherein m is 0 or 1 and R is a hydrogen atom or a methyl or carboxy group, and(a2) one or more compounds of a metal capable of existing in at least two valency states;(b) removing sulphur formed by oxidation of hydrogen sulphide; and(c) re-oxidizing the hydroquinone formed from reduction of the compound of formula I.
    Type: Grant
    Filed: July 24, 1985
    Date of Patent: January 20, 1987
    Assignee: Ciba-Geigy Corporation
    Inventors: Emyr Phillips, Brian Holt
  • Patent number: 4629608
    Abstract: Process for removing H.sub.2 S from the exhaust steam in a geothermal power plant wherein the H.sub.2 S containing steam is contacted with an aqueous solution containing a ferric chelate and a cationic polymeric catalyst such as poly(dimethyldiallyl ammonium chloride). The conversion of H.sub.2 S to sulfur is accelerated by the use of a small amount of the catalyst.
    Type: Grant
    Filed: June 24, 1985
    Date of Patent: December 16, 1986
    Assignee: The Dow Chemical Company
    Inventors: Robert D. Lampton, Jr., Thomas M. Hopkins, II
  • Patent number: 4624838
    Abstract: Disclosed is a process for removing acid gases from gaseous streams by contacting the stream with an aqueous scrubbing solution containing a heterocyclic nitrogen compound comprised of either a five-- or six--membered ring having a pKa no greater than about 8. Imidazole is a preferred heterocyclic nitrogen compound.
    Type: Grant
    Filed: April 29, 1985
    Date of Patent: November 25, 1986
    Assignee: Exxon Research and Engineering Company
    Inventors: Yen-Chi Pan, David W. Savage
  • Patent number: 4622212
    Abstract: In a cyclic hydrogen sulfide oxidation-catalyst regeneration process using an aqueous chelated polyvalent metal catalyst solution, excessive degradation of the aminopolycarboxylic acid chelating agent is prevented by incorporating in the solution an effective amount of a stabilizing agent capable of retarding or preventing rupture of nitrogen-carbon bonds in the chelating agent during oxidative regeneration of the catalyst solution. Alkaline thiosulfates are the preferred stabilizing agents. Particularly good results are obtained using an alkaline thiosulfate stabilizer in a catalyst solution comprising the dimer form of the NTA-iron complex.
    Type: Grant
    Filed: June 25, 1985
    Date of Patent: November 11, 1986
    Assignee: ARI Technologies Inc.
    Inventors: Derek McManus, Frederick R. Kin
  • Patent number: 4618481
    Abstract: An alkaline absorbent composition comprising a severely hindered amino compound and an amine salt is provided. A process for the removal of H.sub.2 S from fluid mixtures using this absorbent composition to produce a very low level of H.sub.2 S in the treated fluid is also provided. The process is also suited for the selective removal of H.sub.2 S from fluid mixtures comprising H.sub.2 S and CO.sub.2.
    Type: Grant
    Filed: August 30, 1985
    Date of Patent: October 21, 1986
    Assignee: Exxon Research and Engineering Co.
    Inventors: Fred J. Heinzelmann, Noah S. Rothblatt, James P. Glass, Jr., Geoffrey R. Say, George R. Chludzinski, Guido Sartori, W. S. Winston Ho
  • Patent number: 4614644
    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).
    Type: Grant
    Filed: September 13, 1985
    Date of Patent: September 30, 1986
    Assignee: The Dow Chemical Company
    Inventors: Robert D. Lampton, Jr., Thomas M. Hopkins, II
  • Patent number: 4605475
    Abstract: A process for separating oxygen from gas mixture containing oxygen is disclosed. The gas mixtures are contacted with a solution of an organometallic complex oxygen carrier and an electrolyte in an organic solvent. During the contact, oxygen is bound to the carrier. After the contacting step is completed the solution is electrochemically oxidized with resultant release of oxygen which is recovered. The solution is then electrochemically reduced bringing the oxygen carrier to its original condition and ready for reuse.
    Type: Grant
    Filed: January 28, 1985
    Date of Patent: August 12, 1986
    Assignee: SRI International
    Inventors: Daryl L. Roberts, Richard M. Laine
  • Patent number: 4603035
    Abstract: A Stretford process for removing hydrogen sulfide from a high volumetric flow gas stream includes devices for introducing transverse momentum components in a multiphase flow. These momentum components enhance gas/liquid contact and improve the efficiency of hydrogen sulfide removal. Various devices for introducing the momentum components are disclosed including baffle trays, static mixer and tertiary spray devices.
    Type: Grant
    Filed: September 30, 1983
    Date of Patent: July 29, 1986
    Assignee: Chevron Research Company
    Inventors: David E. Connell, Colin M. Chapman
  • Patent number: 4592905
    Abstract: A hydrogen sulfide gas is converted to sulfur and hydrogen gas by reacting the hydrogen sulfide and with an anthraquinone dissolved in a polar hydrocarbon solvent. The hydrogen sulfide reacts with the anthraquinone to produce sulfur and an anthrahydroquinone. Sulfur is then removed from the solvent. The anthraquinone is regenerated from the anthrahydroquinone yielding hydrogen gas. The anthraquinone is recycled with the solvent to the reaction.
    Type: Grant
    Filed: January 14, 1985
    Date of Patent: June 3, 1986
    Assignee: Marathon Oil Company
    Inventors: Mark A. Plummer, Phillip M. Beazley
  • Patent number: 4556546
    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.
    Type: Grant
    Filed: August 14, 1984
    Date of Patent: December 3, 1985
    Assignee: Air Products and Chemicals, Inc.
    Inventors: William F. Burgoyne, Jr., Michael S. Chen, Dale D. Dixon, Thomas J. Edwards
  • Patent number: 4541998
    Abstract: A process is described for preventing the formation of thiosulfate in oxidative hydrogen sulfide scrubbings. For this purpose, an aqueous alkaline scrubbing agent, containing an oxidizing agent, is used, the hydrogen sulfide being absorbed from the scrubbing agent in a scrubbing column and oxidized principally to elementary sulfur with reduction of the oxidizing agent. Subsequently, the scrubbing agent is regenerated for reuse by exposure to an oxygen-containing gas for the reoxidation of the oxidizing agent. A thiocyanate is added to the scrubbing agent, advantageously in a concentration of 0.06 to 0.5 mol/l, preferably 0.3 to 0.4 mol/l.
    Type: Grant
    Filed: October 12, 1983
    Date of Patent: September 17, 1985
    Assignee: Linde Aktiengesellschaft
    Inventor: Gunter Weber
  • Patent number: 4540561
    Abstract: A process 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 reactant solution comprising iron (Fe III) lignosulfonate. The hydrogen sulfide is converted to sulfur, and the reactant is reduced. The process may be cyclic, and may include sulfur removal and regeneration of the reactant.
    Type: Grant
    Filed: December 24, 1984
    Date of Patent: September 10, 1985
    Assignee: Shell Oil Company
    Inventor: Donald C. Olson
  • Patent number: 4540552
    Abstract: A process for the removal of acid gases which are reactive with ethylene oxide from a gas mixture containing carbon dioxide, comprises contacting the gas mixture with ethylene carbonate containing sufficient amount of ethylene oxide, whereby the ethylene oxide reacts chemically with the acid gases to produce reaction products which are more easily removable from the gas mixture.
    Type: Grant
    Filed: May 24, 1984
    Date of Patent: September 10, 1985
    Assignee: Union Carbide Corporation
    Inventors: Bernard C. Ream, Cyril Tellis
  • Patent number: 4539189
    Abstract: Process and composition for removing H.sub.2 S and like sulfides from gas streams by contact with a substituted aromatic nitrile having an electron-attracting substituent on the aromatic ring at least as strong as halogen (e.g., isophthalonitrile) and an organic tertiary amine in an inert organic solvent such as N-methyl-2-pyrrolidone.
    Type: Grant
    Filed: January 23, 1984
    Date of Patent: September 3, 1985
    Assignee: Chevron Research Company
    Inventors: Robert Starkston, Mark C. Luce, Robert V. Homsy
  • Patent number: 4537752
    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.
    Type: Grant
    Filed: July 17, 1984
    Date of Patent: August 27, 1985
    Assignee: Linde Aktiengesellschaft
    Inventor: Gunter Weber
  • Patent number: 4536381
    Abstract: An integrated process for modifying the H.sub.2 /CO ratio in specified gaseous streams is disclosed, the process being characterized by bulk removal of H.sub.2 S, adjustment of H.sub.2 /CO ratio by water gas (or carbon monoxide) shift, and removal of remaining H.sub.2 S. CO.sub.2 may be recovered, and the process may be operated to produce a gas comprising principally hydrogen.
    Type: Grant
    Filed: December 20, 1983
    Date of Patent: August 20, 1985
    Assignee: Shell Oil Company
    Inventor: George C. Blytas
  • Patent number: 4536382
    Abstract: An integrated process for modifying the H.sub.2 /CO ratio in specified gaseous streams is disclosed, the process being characterized by bulk removal of H.sub.2 S, adjustment of H.sub.2 /CO ratio by water gas (or carbon monoxide) shift, and removal of remaining H.sub.2 S. CO.sub.2 may be recovered, and the process may be operated to produce a gas comprising principally hydrogen.
    Type: Grant
    Filed: December 20, 1983
    Date of Patent: August 20, 1985
    Assignee: Shell Oil Company
    Inventor: George C. Blytas
  • Patent number: 4534955
    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.
    Type: Grant
    Filed: July 1, 1983
    Date of Patent: August 13, 1985
    Assignee: Chevron Research Company
    Inventor: John M. Rosenbaum
  • Patent number: 4532117
    Abstract: A method, applicable to hydrogen sulfide removal systems which employ a regenerable aqueous washing solution capable of absorbing hydrogen sulfide and converting that hydrogen sulfide to elemental sulfur, is provided for reconditioning such systems after they have become contaminated with sulfur-feeding bacteria and/or for maintaining such systems substantially free of such bacteria. In the method of the invention, the aqueous washing solution is contacted with an aliphatic dialdehyde.
    Type: Grant
    Filed: December 20, 1983
    Date of Patent: July 30, 1985
    Assignee: Union Oil Company of California
    Inventor: Dennis D. Delaney
  • Patent number: 4532118
    Abstract: A process for the removal of hydrogen sulfide from a gas which comprises contacting the gas with a solution comprising ferric ions (Fe.sup.3+) and ferrous ions (Fe.sup.2+). The solution further comprises ethylenediamine tetraacetic acid (EDTA) or a salt thereof and triethanolamine (TEA) or a salt thereof. The solution has a pH in the range of from 7 to 9 and a mole ratio of ferric ion to total iron ions in the range of from 0.60 to 0.90 as measured just after the hydrogen sulfide contacts the solution. The process is characterized by high removal of hydrogen sulfide, prevention of side reactions, and the inhibition of the formation of intermediate colloidal sulfur.
    Type: Grant
    Filed: March 29, 1984
    Date of Patent: July 30, 1985
    Assignee: Kimura Chemical Plants Co., Ltd.
    Inventors: Tadaaki Tajiri, Hitoshi Nishizawa
  • Patent number: 4532116
    Abstract: The gas which contains sulfur compounds consisting of H.sub.2 S and/or COS is scrubbed with an absorbent solution which contains at least one amine. The gas to be desulfurized which enters the scrubbing zone is at a temperature in the range of 25.degree. to 100.degree. C. and rises in the scrubbing zone in a countercurrent to the scrubbing solution. The gas leaving the absorbent solution is indirectly cooled to a temperature which is at least 20.degree. C. below the entrance temperature of the gas and is not below 5.degree. C. The indirect cooling results in a condensate, which contains at least one secondary amine. That condensate is passed through the scrubbing zone as an absorbent solution. The condensate leaving the scrubbing zone contains at least 10 moles secondary amine and preferably at least 100 moles secondary amine per mole H.sub.2 S and COS in the gas to be desulfurized.
    Type: Grant
    Filed: November 4, 1983
    Date of Patent: July 30, 1985
    Assignee: Metallgesellschaft Aktiengesellschaft
    Inventors: Alexander Doerges, Johann Schlauer, Manfred Kriebel, Anton Hude
  • Patent number: 4532114
    Abstract: Steam from a geothermal source is usually contaminated with gaseous impurities including, inter alia, one or more substances comprising boron, arsenic and mercury. Such contaminants are detrimental to the equipment utilizing the steam as an energy source and also result in environmental pollution. Herein, a flow of geothermal steam at elevated temperature and superatmospheric pressure is processed upstream of said equipment by contacting the steam with an aqueous liquid whereby said impurities are extracted from the steam and transferred to the aqueous liquid while maintaining the steam at substantially said elevated temperature and pressure.
    Type: Grant
    Filed: June 22, 1983
    Date of Patent: July 30, 1985
    Assignee: Deuterium Corporation
    Inventor: Jerome S. Spevack
  • Patent number: 4526773
    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.
    Type: Grant
    Filed: November 14, 1983
    Date of Patent: July 2, 1985
    Assignee: Linde Aktiengesellschaft
    Inventor: Gunter Weber
  • Patent number: 4525338
    Abstract: A two stage process for removing and subsequently recovering sulfur values from hydrogen sulfide or mercaptan-contaminated feed gas streams is disclosed. The process employs a polyvalent metal ion chelate redox couple to convert S.sup.-- to S and uses the metal ion reoxidation gas stream to remove the solid sulfur overhead as a flotation froth. The feed gas stream is contacted with the chelate in a first contacting zone, and additionally in the reoxidation zone.
    Type: Grant
    Filed: June 7, 1984
    Date of Patent: June 25, 1985
    Assignee: Chevron Research Company
    Inventor: Howard W. Klee, Jr.
  • Patent number: 4525294
    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.
    Type: Grant
    Filed: April 14, 1983
    Date of Patent: June 25, 1985
    Assignee: Exxon Research and Engineering Co.
    Inventors: Guido Sartori, Warren A. Thaler
  • Patent number: 4522638
    Abstract: A process for regulating the NH.sub.3 content in an organic liquid that acts as a physical scrubbing agent and is used in a procedure for absorbing sour gases from gaseous mixtures. To ensure undisturbed and reliable carrying out of the scrubbing process, an ammonia-precipitating precipitant is added to the scrubbing agent and the precipitate is then separated from the scrubbing agent. Preferred precipitants include sulphuric acid and phosphuric acid. The ammonia salts are effective fertilizers.
    Type: Grant
    Filed: May 22, 1984
    Date of Patent: June 11, 1985
    Assignee: Linde AG
    Inventor: Heinz Karwat
  • Patent number: 4519991
    Abstract: Improvement in the enrichment of a gas in hydrogen sulphide, comprising selective absorption by a liquid in a primary absorption zone, regeneration of the liquid by heating and/or stripping by an inert gas with liberation of the gases absorbed and recovery of a fraction of the liberated gases, the remainder being subjected to a second absorption in a secondary absorption zone by a new or regenerated absorbent liquid identical with that used in the primary absorption zone; in one and the same zone of operation, common to the regeneration and the secondary absorption zones, there occur simultaneously: arrival of the liquid from the first absorption, movement of the gases liberated during regeneration, flow of the liquid derived from the secondary absorption and discharge of a fraction of the liberated gases enriched in H.sub.2 S.
    Type: Grant
    Filed: December 21, 1983
    Date of Patent: May 28, 1985
    Assignee: Societe Nationale Elf Anquitaine
    Inventors: Olivier Oliveau, Claude Blanc
  • Patent number: 4518577
    Abstract: A cyclic process for the removal of H.sub.2 S from a sour gaseous stream is disclosed, the process being characterized by the reaction of the H.sub.2 S to sulfur employing aqueous solutions of oxidizing polyvalent metal chelates of specified organic acids, and by the recovery of the sulfur from the solutions with specific extractants. The extractants are selected from compounds (and mixtures thereof) having the formula C.sub.n H.sub.2(n+1), wherein n is a whole number from 4 through 8, and the recovery may be made prior or subsequent to regeneration of the polyvalent metal chelate solution.
    Type: Grant
    Filed: December 20, 1982
    Date of Patent: May 21, 1985
    Assignee: Shell Oil Company
    Inventor: Miro E. Klecka
  • Patent number: 4518576
    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.
    Type: Grant
    Filed: December 20, 1983
    Date of Patent: May 21, 1985
    Assignee: Shell Oil Company
    Inventor: Zaida Diaz
  • Patent number: 4517170
    Abstract: A cyclic process for the removal of H.sub.2 S from a sour gaseous stream is disclosed, the process being characterized by the reaction of the H.sub.2 S to sulfur employing aqueous solutions of oxidizing polyvalent metal chelates of nitrilotriacetic acid, and by the recovery of the sulfur from the solutions with specific extractants. The extractants are selected from compounds (and mixtures thereof) having the formula C.sub.n H.sub.2(n+l), wherein n is a whole number from 4 through 8, and the recovery may be made prior or subsequent to regeneration of the polyvalent metal chelate solution.
    Type: Grant
    Filed: December 20, 1982
    Date of Patent: May 14, 1985
    Assignee: Shell Oil Company
    Inventor: Miro E. Klecka
  • Patent number: 4515764
    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.
    Type: Grant
    Filed: December 20, 1983
    Date of Patent: May 7, 1985
    Assignee: Shell Oil Company
    Inventor: Zaida Diaz