Utilizing Reactant Containing Arsenic, Phosphorus, Or Boron Patents (Class 423/223)
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Patent number: 4824443Abstract: There is disclosed a composite immobulized liquid membrane of a solvent-swollen polymer and a microporous organic or inorganic support, the solvent being at least one highly polar solvent containing at least one nitrogen, oxygen, phosphorous or sulfur atom, and having a boiling point of at least 100.degree. C. and a specified solubility parameter. The solvent or solvent mixture is homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. The membrane is suitable for acid gas scrubbing and oxygen/nitrogen separation.Type: GrantFiled: April 7, 1988Date of Patent: April 25, 1989Assignee: Bend Research, Inc.Inventors: Stephen L. Matson, Eric K. L. Lee, Dwayne T. Friesen, Donald J. Kelly
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Patent number: 4801440Abstract: A process for the simultaneous partial oxidation and desulfurization of sulfur and silicate-containing solid carbonaceous fuel for the production of gaseous mixtures comprising H.sub.2 and CO and containing less than about 0.05 volume % of H.sub.2 S and COS. In the process, the solid carbonaceous fuel and a calcium-containing compound are reacted by partial oxidation in the reaction zone of a free-flow unobstructed gas generator with a controlled amount of 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.-12 atmospheres. The total moles of calcium in the reaction zone is at least equal to about 1.0 times the moles of sulfur in the solid carbonaceous fuel. The partial oxidation and desulfurization reactions take place simultaneously at a temperature which is about 10.degree. to 200.degree. F.Type: GrantFiled: March 2, 1987Date of Patent: January 31, 1989Assignee: Texaco, Inc.Inventors: Mitri S. Najjar, Roger J. Corbeels
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Patent number: 4737166Abstract: A composite immobilized liquid membrane suitable for acid gas scrubbing is disclosed. The membrane is a solvent-swollen polymer and a microporous polymeric support, the solvent being selected from a class of highly polar solvents containing at least one atom selected from nitrogen, oxygen, phosphorous and sulfur, and having a boiling point of at least 100.degree. C. and a solubility parameter of from about 7.5 to about 13.5 (cal/cm.sup.3 -atm).sup.1/2. Such solvents are homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. Also disclosed are methods of acid gas scrubbing of high- and low-Btu gas effluents with such solvent-swollen membranes.Type: GrantFiled: December 30, 1986Date of Patent: April 12, 1988Assignee: Bend Research, Inc.Inventors: Stephen L. Matson, Eric K. L. Lee, Dwayne T. Friesen, Donald J. Kelly
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Patent number: 4659552Abstract: Disclosed are macroreticulate polymer scavengers functionalized with arsenic or phosphorus compounds. These scavengers are used for removing oxidants, protic acids and compounds that can be metallated, from arsine and phosphine.Type: GrantFiled: July 21, 1986Date of Patent: April 21, 1987Assignee: Hercules IncorporatedInventor: Glenn M. Tom
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Patent number: 4581209Abstract: The present invention relates to an alkaline salt promoter system which includes an N-aminoalkyl alkylpiperazine, preferably the compound 1-(3-aminopropyl)-2,5-dimethylpiperazine (APDP), an alkali metal salt or hydroxide (e.g., K.sub.2 CO.sub.3) and water. These scrubbing compositions may be used for removing CO.sub.2 from gaseous streams containing CO.sub.2.Type: GrantFiled: October 3, 1983Date of Patent: April 8, 1986Assignee: Exxon Research and Engineering Co.Inventors: Alexis A. Oswald, Guido Sartori, David W. Savage, Warren A. Thaler
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Patent number: 4525294Abstract: 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: GrantFiled: April 14, 1983Date of Patent: June 25, 1985Assignee: Exxon Research and Engineering Co.Inventors: Guido Sartori, Warren A. Thaler
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Patent number: 4518576Abstract: 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: GrantFiled: December 20, 1983Date of Patent: May 21, 1985Assignee: Shell Oil CompanyInventor: Zaida Diaz
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Patent number: 4515764Abstract: 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: GrantFiled: December 20, 1983Date of Patent: May 7, 1985Assignee: Shell Oil CompanyInventor: Zaida Diaz
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Patent number: 4515759Abstract: Process for the removal of hydrogen sulfide from gas mixtures, particular gas mixtures containing hydrocarbons, wherein the gas mixture is treated with an aqueous solution of a water soluble nitrite such as sodium nitrite, the pH of the aqueous solution being at least 5.5 or greater.Type: GrantFiled: November 3, 1983Date of Patent: May 7, 1985Assignee: NL Industries, Inc.Inventors: Edward E. Burnes, Kishan Bhatia
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Patent number: 4479929Abstract: 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.Type: GrantFiled: December 9, 1982Date of Patent: October 30, 1984Assignee: Mineral & Chemical Resource Co.Inventor: F. Hilton Lacy, Jr.
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Patent number: 4471138Abstract: A novel class of severely sterically hindered secondary aminoether alcohols of the general formula: ##STR1## are prepared wherein R.sub.1 and R.sub.2 are each selected from the group consisting of alkyl and hydroxylalkyl radicals R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are each selected from the group consisting of hydrogen, alkyl and hydroxyalkyl radicals, with the proviso that at least one of R.sub.4 or R.sub.5 bonded to the carbon atom directly bonded to the nitrogen atom is an alkyl or hydroxyalkyl radical when R.sub.3 is hydrogen, x and y are each positive integers ranging from 2-4 and z is a positive integer ranging from 1-4. The compounds are useful in the selective removal of H.sub.2 S from mixtures containing H.sub.2 S and CO.sub.2.Type: GrantFiled: December 27, 1982Date of Patent: September 11, 1984Assignee: Exxon Research and Engineering Co.Inventor: Eugene L. Stogryn
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Patent number: 4460554Abstract: A process for removing hydrogen sulfide from sour gas streams is disclosed which is carried out in processing equipment which includes steel components resulting in iron from the steel slowly dissolving in the alkaline H.sub.2 S absorption medium. The solubilized iron tends to react with the hydrogen sulfide to form iron sulfide which further oxidizes to produce sodium thiosulfate. The preferred absorption medium includes a metal vanadate and boron complex, a quinone type reoxidation catalyst and a metal ferri or ferrocyanide decahydrate compound capable of reacting with the solubilized iron in the alkaline absorption medium to form a precipitate which is unreactive with the dissolved hydrogen sulfide.Type: GrantFiled: March 31, 1983Date of Patent: July 17, 1984Assignee: Purtec Systems, Inc.Inventor: Ronald E. Shafer
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Patent number: 4434144Abstract: The removal of CO.sub.2 and mixtures thereof with H.sub.2 S from gaseous mixture containing same, is carried out by using an absorbing solution which comprises a first activating substance chosen from aminoacids and primary and secondary ethanolamines, which effects the initial absorption of CO.sub.2 with formation of a carbamate, a second activating substance chosen from As.sub.2 O.sub.3 and its derivatives, secondary ethanolamines and ammonia, which promotes the hydrolysis and decomposition of the carbamate as the latter forms, and a third substance of a basic nature, which effects the quantitative absorption of CO.sub.2 or CO.sub.2 +H.sub.2 S.Type: GrantFiled: October 9, 1981Date of Patent: February 28, 1984Inventors: Giuseppe Giammarco, Paolo Giammarco
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Patent number: 4430312Abstract: An improved, catalyzed process for the removal of CO.sub.2 from gas mixtures is described using a solution containing 15-40% by weight of potassium carbonate in which the absorption efficiency is enhanced by the addition of sodium or potassium vanadate equivalent to 2 to 10% by weight of V.sub.2 O.sub.5 and sodium or potassium borate equivalent to 1 to 10% by weight of KBO.sub.2 in which the weight ratio of equivalent KBO.sub.2 to equivalent V.sub.2 O.sub.5 is less than 1.5:1. It has been found that use of the described catalysts permits significant reductions in solution circulation rates (up to 45%), which leads to equipment and utility economies.Type: GrantFiled: June 23, 1982Date of Patent: February 7, 1984Inventor: Allen G. Eickmeyer
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Patent number: 4417075Abstract: A novel class of di-secondary aminoethers of the general formula: ##STR1## are disclosed wherein R.sub.1 and R.sub.8 are each independently selected from the group consisting of primary alkyl having 1 to 8 carbon atoms and primary hydroxyalkyl having 2 to 8 carbon atoms, secondary alkyl and secondary hydroxyalkyl radicals having 3 to 8 carbon atoms, tertiary alkyl and tertiary hydroxyalkyl radicals having 4 to 8 carbon atoms, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 are each independently selected from the group consisting of hydrogen, C.sub.1 -C.sub.3 alkyl and hydroxyalkyl radicals, with the proviso that R.sub.2, R.sub.3, R.sub.6, and R.sub.7 are C.sub.1 -C.sub.4 alkyl or hydroxyalkyl radicals when R.sub.1 and R.sub.8 are primary alkyl or hydroxyalkyl radicals, and at least one of R.sub.2 or R.sub.3 and R.sub.6 or R.sub.7 are C.sub.1 to C.sub.3 alkyl or hydroxyalkyl radicals when R.sub.1 and R.sub.Type: GrantFiled: January 18, 1982Date of Patent: November 22, 1983Assignee: Exxon Research and Engineering Co.Inventor: Eugene L. Stogryn
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Patent number: 4409191Abstract: A process for removing acid gases such as CO.sub.2 and H.sub.2 S from gas streams using a cyclic aqueous alkaline scrubbing solution which is circulated between an absorption and regeneration stage is disclosed. This process is improved by integrating within this cyclic system a process scheme wherein condensed steam having gaseous impurities dissolved therein is recovered from the feed gas and subjected to a pressure below which scrubbing solution regeneration takes place. While maintaining this pressure, the process condensate is heated, boiled and stripped to evolve a vaporous mixture comprising steam and gaseous impurities which are compressed and introduced into the regeneration stage. By this process, useful work is performed by low temperature process streams thereby improving the overall efficiency of the cyclic process.Type: GrantFiled: January 4, 1982Date of Patent: October 11, 1983Assignee: Exxon Research & Engineering Co.Inventor: Robert M. Osman
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Patent number: 4405577Abstract: The present invention relates to an alkaline promoter system comprising specific mixtures of nonsterically hindered amino compounds and sterically hindered amino acids and their use in acid gas scrubbing processes. The preferred promoter system comprises a mixture of (i) diethanol amine or 1,6-hexanediamine and (ii) N-secondary butyl glycine or pipecolinic acid.Type: GrantFiled: November 13, 1981Date of Patent: September 20, 1983Assignee: Exxon Research and Engineering Co.Inventors: Guido Sartori, David W. Savage
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Patent number: 4405578Abstract: The present invention relates to an alkaline salt promoter system comprising specific mixtures of lower aliphatic mono-substituted alpha amino acids and sterically hindered diamino or triamino compounds and their use in acid gas scrubbing processes. The preferred promoter system comprises a mixture of N-secondary butyl glycine and N-cyclohexyl-1,3-propanediamine or N-cyclohexyl-1, 4-butanediamine.Type: GrantFiled: November 13, 1981Date of Patent: September 20, 1983Assignee: Exxon Research and Engineering Co.Inventors: Guido Sartori, Warren A. Thaler
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Patent number: 4405579Abstract: The present invention relates to an alkaline salt promoter system comprising specific mixtures of sterically hindered monosubstituted alpha-amino acids and tertiary amino acids and its use in acid gas scrubbing processes. The preferred promoter system comprises a mixture of N-secondary butyl glycine and N-methyl-N-secondary butyl glycine.Type: GrantFiled: November 13, 1981Date of Patent: September 20, 1983Assignee: Exxon Research and Engineering Co.Inventors: Guido Sartori, Warren A. Thaler
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Patent number: 4399111Abstract: In the removal of sour gases by scrubbing with an aqueous alkali metal salt solution, e.g. a solution of K.sub.2 CO.sub.3, the circulating scrubbing liquid is gradually contaminated with organic acids, especially formic acid, which in turn ties up K.sup.+ as the formate which is ineffective for scrubbing purposes. To remove the organic acids, at least a partial stream of the circulating scrubbing liquid is subjected to an oxidation step under conditions leading to the oxidation of the salts of the organic acids, thereby liberating the bound alkali metal ions. If the scrubbing liquid contains an oxidizable activator, the latter can be extracted prior to oxidation of the scrubbing liquid and added back subsequent to the oxidation.Type: GrantFiled: April 14, 1982Date of Patent: August 16, 1983Assignee: Linde AktiengesellschaftInventors: Karl Baur, Eberhard Lassmann, Heinz Karwat
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Patent number: 4376102Abstract: Acidic gases containing carbon dioxide are removed from a normally gaseous mixture by absorbing CO.sub.2 from the gaseous mixture with an aqueous solution comprising a basic alkali metal salt or hydroxide and an activator or promoter system for the salt or hydroxide which contains (i) at least one diaminoalcohol of the formula:H.sub.2 N--(CH.sub.2).sub.4 --NRR'wherein R and R' each independently represent a C.sub.1 -C.sub.6 alkyl group and either R or R' or both R and R' have a pendant hydroxyl group, and (ii) an amino acid, and desorbing at least partially the absorbed CO.sub.2 from the aqueous solution.Type: GrantFiled: December 2, 1981Date of Patent: March 8, 1983Assignee: Exxon Research and Engineering Co.Inventors: Warren A. Thaler, Guido Sartori, Chang J. Kim
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Patent number: 4376101Abstract: Acidic gases containing carbon dioxide are removed from a normally gaseous mixture by absorbing CO.sub.2 from the gaseous mixture with an aqueous solution comprising a basic alkali metal salt or hydroxide and an activator or promoter system for the salt or hydroxide which contains (i) at least one non-sterically hindered diamine defined as having both a primary and a tertiary amino moiety wherein the primary amino moiety is attached to a primary carbon atom, and (ii) an amino acid, and desorbing at least partially the absorbed CO.sub.2 from the aqueous solution.Type: GrantFiled: November 13, 1981Date of Patent: March 8, 1983Assignee: Exxon Research and Engineering Co.Inventors: Guido Sartori, Chang J. Kim, Michael T. Melchior, David W. Savage
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Patent number: 4292286Abstract: A cyclic urea reaction product forms as a by-product of a hindered amine acid gas scrubbing process and results in an ultimate buildup of the material in the circulating amine scrubbing solution. The buildup of this material has a deleterious effect on acid gas removal rates and accordingly, results in inefficient acid gas removal. In the process of the present invention, the cyclic urea degradation product is removed from the circulating solution by employing a selective precipitation of the cyclic urea followed by filtration. The selective precipitation is carried out by cooling the circulating solution to a particular temperature level such that the cyclic urea comes out of solution while the other components remain in solution.Type: GrantFiled: December 11, 1979Date of Patent: September 29, 1981Assignee: Exxon Research & Engineering Co.Inventors: Geoffrey R. Say, James R. Hays, Sr., Jagannathan N. Iyengar
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Patent number: 4282194Abstract: Acidic gases such as carbon dioxide are removed from a normally gaseous mixture including the acidic component by contacting the gaseous mixture in an absorption zone with an acid absorbing scrubbing solution comprising a basic alkali metal compound and an activator for the compound, during which process at least a portion of the activator is converted to a cyclic urea. The solution is then transferred to the desorption zone to remove at least a portion of the absorbed acidic component. At least a portion of the partially desorbed scrubbing solution containing the cyclic urea is transferred from the desorption zone to a thermal conversion zone maintained at an elevated temperature wherein at least a portion of the cyclic urea is converted back to the activator.Type: GrantFiled: February 19, 1980Date of Patent: August 4, 1981Assignee: Exxon Research & Engineering Co.Inventors: Geoffrey R. Say, James R. Hays, Sr., Jagannathan N. Iyengar, Barbara A. Hacker
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Patent number: 4282193Abstract: Acidic gases such as carbon dioxide are removed from a gaseous mixture including the acidic component by contacting the gaseous mixture in a scrubbing system with an acid absorbing solution comprising a basic alkali metal compound and an activator, during which process at least a portion of the activator is converted to cyclic urea. At least a portion of the scrubbing solution is transferred to a thermal conversion zone wherein at least a portion of the cyclic urea is converted back to the activator afterwhich the scrubbing solution is returned to the scrubbing system from the thermal conversion zone.Type: GrantFiled: February 19, 1980Date of Patent: August 4, 1981Assignee: Exxon Research & Engineering Co.Inventors: Michael T. Melchior, George E. Milliman, Chang J. Kim, George R. Chludzinski
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Patent number: 4271132Abstract: The invention relates to an absorption desorption composition and process employing said composition for selectively removing acidic gases, particularly carbon dioxide (CO.sub.2) and hydrogen sulphide (H.sub.2 S) from gaseous mixtures, said composition comprising an aqueous solution containing a major proportion of alkali metal salts, potassium carbonate and potassium borate, a minor proportion of a catalytic activator, and a corrosion inhibitor when required, with provision for maintaining the inhibitor in an effective condition and in condition to perform its corrosion reducing function; the process characterized by two stages of absorption and desorption connected in a circulating system for the fluids being processed with suitable temperature and pressure controls, whereby an increased amount of the contaminating gases are removed and corrosive and side reaction difficulties reduced to a minimum.Type: GrantFiled: March 15, 1971Date of Patent: June 2, 1981Inventor: Allen G. Eickmeyer
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Patent number: 4258019Abstract: A process for the selective removal of hydrogen sulfide from a gas containing hydrogen sulfide and carbon dioxide wherein said gas is contacted at superatmospheric pressure with an alkali metal carbonate solution, the resultant solution which contains hydrosulfide and bicarbonate is subjected to pressure reduction, the total alkali metal bicarbonate content of the resultant solution is adjusted so that it is at least 55% of the total alkali content of the solution and the said solution is then stripped and recycled to the hydrogen sulfide absorption step.Type: GrantFiled: July 6, 1978Date of Patent: March 24, 1981Assignee: Metallgesellschaft AktiengesellschaftInventors: Heinz Hiller, Johann Schlauer, Alexander Doerges, Georg Kempf, Vaclav Svoboda, Winfried Zeschmar
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Patent number: 4217238Abstract: Acidic components are removed from gaseous mixtures by contacting the gaseous mixture with an aqueous solution comprising (1) a basic salt and (2) an activator for said basic salt comprising at least one sterically hindered amine and an aminoacid which is a cosolvent for the sterically hindered amines. The aminoacid serves to prevent phase separation of the aqueous solution at high temperatures and low fractional conversions during the contacting.Type: GrantFiled: September 22, 1977Date of Patent: August 12, 1980Assignee: Exxon Research & Engineering Co.Inventors: Guido Sartori, David W. Savage
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Patent number: 4198378Abstract: A process for removing gaseous impurities such as CO.sub.2 and/or H.sub.2 S from a gaseous mixture obtained by reacting combustible substances with steam, said steam being produced in boilers fed with water previously purified in degassing columns. The gaseous impurities are removed by means of an absorbent solution and the latter is regenerated in a regeneration column by stripping with steam. The stripping steam necessary for the degassing is delivered, at a pressure at least equal to that in the regeneration column, to the degassing columns and then to the regeneration column. The boiler feed water to be purified is previously heated, by supply of residual heats, to a temperature in the vicinity of the boiling temperature of the absorbent solution in the regeneration column.Type: GrantFiled: November 2, 1977Date of Patent: April 15, 1980Inventors: Giuseppe Giammarco, Paolo Giammarco
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Patent number: 4180548Abstract: A cyclic urea reaction product forms as a by-product of a hindered amine acid gas scrubbing process and results in an ultimate buildup of the material in the circulating amine scrubbing solution. The buildup of this material has a deleterious effect on acid gas removal rates and accordingly, results in inefficient acid gas removal. In the process of the present invention, the cyclic urea degradation product is removed from the circulating solution by employing a selective precipitation of the cyclic urea followed by filtration. The selective precipitation is carried out by cooling the circulating solution to a particular temperature level such that the cyclic urea comes out of solution while the other components remain in solution.Type: GrantFiled: December 22, 1978Date of Patent: December 25, 1979Assignee: Exxon Research & Engineering Co.Inventors: Geoffrey R. Say, James R. Hays, Sr., Jagannathan N. Iyengar
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Patent number: 4160810Abstract: A process for removing acid gases such as CO.sub.2 and H.sub.2 S from gas streams using an aqueous alkaline scrubbing solution which is circulated between an absorption and regeneration stage wherein the stripping steam for regeneration is derived at least partly from the hot feed gas to be purified. The thermal efficiency of the process is substantially improved by first heat-exchanging the hot feed gas with the scrubbing solution to raise stripping steam and then heat-exchanging the hot feed gas with water (which is preferably condensate water produced in the scrubbing process) in a second heat exchanger operating under reduced pressure, thus recovering additional low-level heat from the feed gas and producing low-pressure steam which is compressed and then utilized as additional stripping steam.Type: GrantFiled: March 7, 1978Date of Patent: July 10, 1979Assignee: Benfield CorporationInventors: Homer E. Benson, Donald H. McCrea
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Patent number: 4146569Abstract: 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.Type: GrantFiled: July 13, 1977Date of Patent: March 27, 1979Inventors: Giuseppe Giammarco, Paolo Giammarco
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Patent number: 4137294Abstract: In scrubbing fuel gases or synthesis gas, absorption is improved by using simple oxygen containing water soluble organic compounds such as the lower alcohols, butanols, or water soluble lower ethers.Type: GrantFiled: April 8, 1976Date of Patent: January 30, 1979Assignee: Metallgesellschaft AktiengesellschaftInventors: Karl Braizler, Alexander Doerges
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Patent number: 4123506Abstract: Certain impure streams, especially those from geothermal sources, are polluted with hydrogen sulfide, ammonia, carbon dioxide, other gases, and finely divided particulate solid matter in a form resembling dust or smoke. These contaminants reduce the efficiency of the steam as a heat transfer fluid, are detrimental to equipment utilizing steam as an energy source, and result in environmental pollution or expensive requirements for limiting the same. Herein so polluted steam is selectively processed in the gaseous state upstream of said equipment to remove hydrogen sulfide therefrom, with or without removing other pollutants, to recover valuable materials therefrom, and to improve the utility of the steam as an energy source. This is done by contacting a flow of the steam with aqueous liquid reactant media consisting essentially of one or more reactive compounds of certain metals which form solid metal sulfide reaction products and which preferably are electropositive with respect to hydrogen.Type: GrantFiled: August 6, 1976Date of Patent: October 31, 1978Assignee: Deuterium CorporationInventor: Jerome S. Spevack
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Patent number: 4117079Abstract: A membrane suitable for absorbing a gas component present in a gaseous stream (e.g. carbon dioxide with a hydrogen feed for an alkaline fuel cell) comprises a porous layer of hydrophilic material, both faces of which are covered by a layer of a mixture of 10 to 90 wt.% of a hydrophobic substance and 90 to 10 wt.% of a hydrophilic substance, the hydrophilic portions of the three layers being impregnated with a carbon dioxide hydration catalyst e.g. sodium meta arsenite, at a concentration of 0.1 to 3M and a 2 to 14N alkali metal buffer solution.The gaseous component is absorbed from a gaseous stream containing said component by causing said stream to flow adjacent to a humidified stripping gas having a relative humidity of 0.4 to 0.95, the flows of said stream and said stripping gas being separated by the membrane.Type: GrantFiled: June 2, 1977Date of Patent: September 26, 1978Assignee: Exxon Research & Engineering Co.Inventor: Richard James Bellows
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Patent number: 4112050Abstract: Carbon dioxide containing acidic gases are removed from a normally gaseous mixture by a process comprising contacting the normally gaseous mixture with an aqueous solution comprising (a) a basic alkali metal salt or hydroxide and (b) an activator for said basic salt or alkali metal salt or hydroxide comprising at least one sterically hindered amine.Type: GrantFiled: December 19, 1977Date of Patent: September 5, 1978Assignee: Exxon Research & Engineering Co.Inventors: Guido Sartori, Frederic Leder
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Patent number: 4112051Abstract: Acidic gases are substantially removed from a normally gaseous mixture by a process comprising contacting the normally gaseous mixture with an amine-solvent liquid absorbent comprising (i) an amine comprised of at least about 50 mol % of a sterically hindered amine, and (ii) a solvent for said amine mixture which is also a physical absorbent for said acidic gases. The liquid absorbent may also include up to about 35 weight percent water.Type: GrantFiled: December 19, 1977Date of Patent: September 5, 1978Assignee: Exxon Research & Engineering Co.Inventors: Guido Sartori, Frederic Leder
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Patent number: 4094957Abstract: Acidic components are removed from gaseous mixtures by contacting the gaseous mixture with an aqueous solution comprising (1) a basic salt and (2) an activator for said basic salt comprising at least one sterically hindered amine and an aminoacid which is a cosolvent for the sterically hindered amines. The aminoacid serves to prevent phase separation of the aqueous solution at high temperatures and low fractional conversions during the contacting.Type: GrantFiled: December 14, 1976Date of Patent: June 13, 1978Assignee: Exxon Research & Engineering Co.Inventors: Guido Sartori, David W. Savage
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Patent number: 4080424Abstract: A hybrid physical-chemical absorbent process using the interrelation between a physical solvent and a H.sub.2 S selective chemical solvent for removal of CO.sub.2 and sulfur containing compounds, principally H.sub.2 S from a mixed gas stream. This process is especially useful in processes such as coal gasification where the incoming stream to the acid gas removal process is at about 1100 psia, 70.degree. F., contains about 15 to 40 mole percent CO.sub.2 at a mole ratio of CO.sub.2 /H.sub.2 S of about 25 to 50. In such cases the product stream contains less than 1 ppm sulfur and less than 3 mole percent CO.sub.2 which is suitable for production of substitute natural gas while the CO.sub.2 atmospheric effluent contains less than 7 ppm sulfur.Type: GrantFiled: February 11, 1976Date of Patent: March 21, 1978Assignee: Institute of Gas TechnologyInventors: Loren N. Miller, Robert A. Macriss, Thomas S. Zawacki
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Patent number: 4080423Abstract: Improved reactive absorbent solutions for absorbing gaseous components are provided by incorporating weakly dissociating compounds in liquid absorbents. When the gaseous component to be dissolved is acid-forming, the absorbent solution should be alkaline, the weakly dissociated compound should be a weak acid or salt thereof, and the pH of the solution should approximate the pK.sub.A of the acid. When the gaseous component is base-forming, the liquid absorbent should be acidic, the weakly dissociating compound should be a weak base, and the pOH of the solution should approximately match the pK.sub.B of the weak base. The weakly dissociated compounds are 1 to 20 times more effective in increasing absorption rates, than additions of equivalent amounts of the primary acidic or basic reactants. Where the absorbed gas is desorbable, the addition of the weakly dissociating compounds has similar effects in increasing the rate of desorption.Type: GrantFiled: April 17, 1974Date of Patent: March 21, 1978Assignee: Massachusetts Institute of TechnologyInventors: Kenneth A. Smith, Jerry H. Meldon, Clark K. Colton
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Patent number: 4073863Abstract: 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.Type: GrantFiled: November 28, 1975Date of Patent: February 14, 1978Inventors: Giuseppe Giammarco, Paolo Giammarco
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Patent number: 4061714Abstract: A process for separating acid gases from gaseous mixtures by absorption in alkaline solutions such as potassium carbonate solution wherin corrosion caused by the absorbing solution is reduced by inclusion therein of an aromatic compound. The aromatic compound has at least one nitro group and at least one hydroxyl group substituted in the same benzene nucleus. The invention is particularly applicable when the absorbent is a potassium carbonate solution activated by arsenic ions.Type: GrantFiled: September 29, 1975Date of Patent: December 6, 1977Assignee: Imperial Chemical Industries LimitedInventor: Mervyn Edward Dennant Turner
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Patent number: 3965243Abstract: A process is described whereby accumulated impurities, consisting mainly of sodium tiocyanate are continuously removed from scrubbing liquors used for removal of hydrogen sulphide from fuel gases and the liquors thereby regenerated and re-used in the hydrogen sulphide scrubbing operation. The thiocyanate is removed by contacting the used scrubbing liquor with an organic solvent, e.g. n-butanol, separating the thiocyanate-bearing solvent from the scrubbing liquor, re-using the treated scrubbing liquor, recovering the thiocyanate from the solvent and re-using the solvent. The extracted sodium thiocyanate can be converted to pure, saleable chemicals or converted to an alkali which can be re-used in the absorbing liquors, thereby producing a completely closed system with no effluent.Type: GrantFiled: September 10, 1974Date of Patent: June 22, 1976Assignee: David Krofchak LimitedInventor: David Krofchak
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Patent number: 3963825Abstract: Gases produced by reacting fuels with oxygen containing gases and water vapor under pressure are desulfurized by scrubbing with a concentrated solution of one or more alkali salts of weak inorganic acids at a temperature near the atmospheric-pressure boiling point of the solution in a column while maintaining an exchange ratio of from 0.2 to 2.0 cubic meters of the concentrated solution per standard cubic meter hydrogen sulfide in the gas to be purified.Type: GrantFiled: May 23, 1972Date of Patent: June 15, 1976Assignee: Metallgesellschaft AktiengesellschaftInventors: Karl Bratzler, Alexander Doerges, Georg Kempf, Paul Rudolph, Johann Schlauer
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Patent number: 3962404Abstract: 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.Type: GrantFiled: February 19, 1974Date of Patent: June 8, 1976Inventors: Giuseppe Giammarco, Paolo Giammarco
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Patent number: 3932582Abstract: The invention relates to an absorption desorption composition and process employing said composition for selectively removing acidic gases, particularly carbon dioxide (CO.sub.2) and hydrogen sulphide (H.sub.2 S) from gaseous mixtures, said composition comprising an aqueous solution containing a major proportion of alkali metal salts, potassium carbonate and potassium borate, a minor proportion of a catalytic activator, and a corrosion inhibitor when required, with provision for maintaining the inhibitor in an effective condition and in condition to perform its corrosion reducing function; the process characterized by two stages of absorption and desorption connected in a circulating system for the fluids being processed with suitable temperature and pressure controls, whereby an increased amount of the contaminating gases are removed and corrosive and side reaction difficulties reduced to a minimum.Type: GrantFiled: November 14, 1974Date of Patent: January 13, 1976Inventor: Allen G. Eickmeyer