Abstract: Improved processes for treating gas streams containing hydrogen sulfide and carbon dioxide, particularly gas streams from fossil fuel gasification processes. The processes rely on the availability of a membrane that maintains high hydrogen sulfide/methane selectivity and adequate hydrogen sulfide/carbon dioxide selectivity when measured with multicomponent gas mixtures at high pressure. The processes have three steps: an acid gas removal step, to remove both hydrogen sulfide and carbon dioxide from the primary gas stream; a membrane fractionation step, to separate hydrogen sulfide from carbon dioxide and create a highly hydrogen-sulfide-concentrated fraction; and a sulfur-fixing step.

Abstract: A mixture of amines made by reacting an amine compound with an aldehyde compound has been found to reduce the levels of H.sub.2 S in liquid or gaseous hydrocarbon streams. At least one of the compounds must have an alkoxyalkylene radical. In one embodiment of the invention, the mixture of amines contains at least one hexahydrotriazine compound of the formula: ##STR1## where R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are independently selected from the group consisting of hydrogen and an alkyl radical, including substituted alkyl radicals, of 1 to 5 carbon atoms; where at least one of the groups is an alkoxyalkylene group. In another embodiment of the invention, the amine mixture may contain other by products, such as the monomers which make up the hexahydrotriazine, with or without the hexahydrotriazine being present. These materials are selective to the reduction of H.sub.2 S levels in hydrocarbon or aqueous streams in the presence of CO.sub.2 which does not compromise their performance.

Abstract: Compositions and a method of using the compositions to inhibit corrosion. The compositions are water soluble n-alkyl morpholine, saturated dicarboxylic acid, optionally alkanol amine and optionally surfactant compositions which inhibit ferrous metal corrosion when added to aqueous oxygen-free solutions.

Abstract: The supported amine-polyol sorbent of the present invention comprises about 1 wt. % to about 25 wt. % amine, about 1 wt. % to about 25 wt. % polyol, with the balance being support. This sorbent is capable of absorbing and desorbing carbon dioxide at relatively high rates at ambient temperatures, thereby improving carbon dioxide sorption capacity.

Abstract: Methods are provided for selectively reducing the levels of hydrogen sulfide and organic sulfides in sewage gas to reduce or remove the odor, toxicity and corrosivity associated therewith, comprising contacting said sewage gas with a composition comprising a trisubstituted hexahydro-s-triazine.

Abstract: A corrosion inhibitor is disclosed which is produced by reacting an aqueous alkanolamine solution with an acid gas to form an amide and an alkanolamine salt, mixing aqueous alkanolamine with said amide and said alkanolamine salt in the absence of added inorganic base, and reacting the mixture at elevated temperature.

Abstract: The levels of hydrogen sulfide and organic sulfides present in gaseous or liquid hydrocarbon streams or mixtures thereof are reduced by contacting the streams with a composition comprising the reaction product of aminoethylpiperazine, an alkanolamine, an etheramine, a polyalkyleneamine, or a polyoxyalkyleneamine with a C1 to C4 aldehyde, including monoaldehydes and dialdehydes, such as ethandial. The solubility of polyamine/aldehyde reaction products is increased by the presence of an enchancing amine/aldehyde reaction product. The enhancing amines include alkanolamines, etheramines, and mixtures thereof.

Abstract: A membrane for the separation of carbon dioxide is disclosed which includes a hydrogel film of a cross-linked, vinyl alcohol/acrylic acid salt copolymer impregnated with an aqueous carrier solution containing a carbon dioxide carrier dissolved therein. A composition containing a solvent, an alkali metal carbonate or bicarbonates, and a polydentate ligand capable of forming a complex with an alkali metal ion is suitably used as the carrier solution. This composition may also be used for the preparation of a liquid film of a carbon dioxide separation membrane.

Abstract: The present invention includes a process for rejuvenating a spent aqueous alkanolamine solution comprising use of alkyl-substituted ammonium-containing organic base treatment to remove inorganic ions.

Abstract: Process for reclaiming or concentrating waste aqueous solutions of gas treating chemicals, such as alkanolamines, used for removing acid components or water vapor from natural gas. The process involves heating the waste solution under a high vacuum to form a vapor and a liquid residue. The temperature and vacuum can be varied to form a vapor consisting mainly of water vapor or a vapor containing both water vapor and vaporized gas treating chemical. The vapor is subsequently condensed or passed through a wash column to produce a concentrated solution. The liquid residue is heated by passing it through a single-pass, generally co-current heater at a rate which avoids localized overheating of a liquid to a temperature above the decomposition temperature of the gas treating chemical. The heated liquid residue is then used to heat the feed waste solution by being thoroughly mixed with it, thus avoiding overheating of the feed solution.

Abstract: A method for recovering carbon dioxide by absorbing carbon dioxide present in a combustion exhaust gas using an aqueous alkanolamine solution, comprising the step of bringing a combustion exhaust gas from which carbon dioxide has been absorbed and removed into contact with water containing carbon dioxide. A method for treating a combustion exhaust gas for denitration using ammonia as a reducing agent and for removal of carbon dioxide by absorption with an aqueous alkanolamine solution, which method comprising the steps of recovering ammonia present in the combustion exhaust gas after the carbon dioxide removal, and using the recovered ammonia as a reducing agent for the denitration. A method for removing CO.sub.2 from a combustion exhaust gas comprising the step of bringing the combustion exhaust gas into contact under atmospheric pressure with an aqueous monoethanolamine solution having a concentration of 35% by weight or more.

Abstract: The supported amine-polyol sorbent of the present invention comprises about 1 wt % to about 25 wt % amine, about 1 wt % to about 25 wt % polyol, with the balance being support. This sorbent is capable of absorbing and desorbing carbon dioxide at relatively high rates at ambient temperatures, thereby improving carbon dioxide sorption capacity.

Abstract: An absorbent liquid having an improved absorption capacity for acidic gaseous compounds due to the presence of an activator of tertiary alkanolamines. The activator is butylmonoethanolamine (BMEA). A process utilizing the absorbent liquid to remove acidic gaseous compounds from a gas.

Abstract: An absorbent liquid for improved absorption capacity for CO.sub.2 in a gas due to the presence of an activator for CO.sub.2 absorbent from the gas, the absorption liquid comprising a mixture of one or more tertiary alkanolamines and an activator of CO.sub.2 absorption by the tertiary alkanolamine, which activator has the general formula Y--(CpH.sub.2p)--NHZ wherein Y is a monovalent radical selected from the group consisting of piperazyl, piperidinyl, furyl, tetrahy-drothienyl and --OR.sub.2 radicals, Z is an R.sub.2 radical or hydrogen, R.sub.2 is a monovalent hydrocarbon residue, and p is an integer from 1 to 6. Also a process for using such absorbent liquid for improved CO.sub.2 absorption from a gas.

Abstract: An electric generating power plant and a method of operation thereof wherein the boiler (1) produces steam to a turbine driven-generator (2), carbon dioxide from combustion exhaust gas emitted from the boiler is simultaneously absorbed in an absorbing solution in an absorber (7), the absorbing solution with the absorbed carbon dioxide is passed through a regenerator (10) where the carbon dioxide is stripped from the absorbing solution, the regenerated absorbing solution is returned to the absorber (7), and steam from either the boiler (1) or turbine of the turbine-driven generator (2) is supplied to a reboiler (13) to provide heat for operation of the regenerator (10). During periods of high demand for electric power steam extraction from the boiler or turbine is discontinued, operation of the regenerator (10) is discontinued and the absorbing solution from the absorber (7) is stored in a first storage unit (15).

Abstract: An apparatus and a process for removing CO.sub.2 from a combustion exhaust gas, by effecting counterflow contact of aqueous alkanolamine solution with the combustion exhaust gas to absorb CO.sub.2 from the gas in the alkanolamine solution and effecting a further contact of the gas with either, condensate water formed by causing condensation of the gas after removal of CO.sub.2, or condensate water formed by causing condensation of the combustion exhaust gas directly after combustion of the fuel. The apparatus includes a tower (1), a first contact section (2) in the tower through which the exhaust gas flows upwardly in counterflow contact with the aqueous alkanolamine solution dispersed by a nozzle device (7) downstream of the first contact section (2), a second contact section (3) in the tower (1) downstream of the nozzle device (7) for effecting counterflow contact of reflux water from a spent absorbent liquor regenerating tower (28) with the gas after removal of CO.sub.2.

Abstract: Process for removing hydrogen sulfide at low concentration in a gas containing water vapor. The gas is cooled to a temperature below the dew point of water, which condenses and separates the water. The dry gas is scrubbed free of hydrogen sulfide by an H.sub.2 S-absorbent solvent forming a purified gas. The purified gas is contacted and rehydrated with heated water so that the water content as water vapor corresponds to a mass flow rate of water substantially equal to the mass flow rate of the water present in the H.sub.2 S-containing gas before cooling. An apparatus for carrying out the process is disclosed.

Abstract: An improved method of reducing the concentration of carbonyl sulfide in a hydrocarbon gas containing carbonyl sulfide, which method comprises (a) feeding the hydrocarbon gas containing carbonyl sulfide to a hydrolysis section to contact the hydrocarbon gas with hot aqueous absorbent to heat the hydrocarbon gas to form hydrolysis section effluent absorbent and hydrolysis section effluent gas containing carbon dioxide and hydrogen sulfide and having a lower concentration of carbonyl sulfide than the hydrocarbon gas; (b) withdrawing and cooling the hydrolysis section effluent absorbent to form a cool aqueous absorbent; (c) cooling the hydrolysis section effluent gas in a cooling section by contacting the hydrolysis section effluent gas with the cool aqueous absorbent to form warm aqueous absorbent and a cooling section effluent gas containing hydrogen sulfide and carbon dioxide; (d) heating the warm aqueous absorbent to form hot aqueous absorbent; (e) feeding the hot aqueous absorbent to the hydrolysis section;

Abstract: The present invention provides a process for removing heat stable salts which accumulate in alkanolamine gas purification process units. Surprisingly, it has been found that weakly acidic cationic exchange resins are dramatically more effective for removing heat stable salts from alkanolamine solutions than strongly acidic cationic exchange resins.Specifically, it has been found in accordance with the invention that ion exchange resins are useful for purifying used aqueous alkanolamine solutions, in the following order of preference: Weak Acid IX>Weak Base IX>Strong Acid IX>Strong Base IX.

Abstract: Liquid absorbing acid gas compounds presenting an improved CO.sub.2 absorption capacity, said absorbing liquid containing one or a plurality of tertiary alkanolamines and a CO.sub.2 absorption activator. The activator is comprised of at least one amino compound selected among polyalkylene-polyamines, alkylenediamines or cycloalkylenediamines, the aminoalkylated compounds of heterocycles such as piperazine, piperidine, furan, thiophene, tetrahydrofuran and tetrahydrothiophene, the alkoxyalkylamines and the alkylmono-alkanolamines having an alkyl residue in at least C.sub.2. Application of said absorbent liquid to the deacidification of gases containing CO.sub.2 and optionally other acid gas compounds, particularly H.sub.2 S and/or COS.

Abstract: A process is disclosed for the removal of heat stable salts from ethanolamine gas purification process units using ion-exchange resins and for regenerating said ion-exchange resins in-situ.

Abstract: A method for removing mercury from natural gas comprises addition of a sulfur-containing agent to form sulfides of mercury, addition of organic base to absorb hydrogen sulfide, and subsequent contact of said natural gas with a molecular sieve to remove water therefrom, further comprising contacting said organic base-containing natural gas with a guard bed to substantially remove said organic base prior to said removing of water.

Abstract: The invention relates to an alkanolamine composition for the removal of acid gas impurities comprising CO2, H2S, COS, or mixtures thereof, from a gaseous or liquefied gas stream containing said acid gases, and to a process of using the alkanolamine composition. The process involves contacting the gas stream with the alkanolamine composition, or an aqueous solution thereof, comprising a mixture of methyldiethanolamine (MDEA) and methylmonoethanolamine (MMEA) in an amount sufficient to generate in situ at least 5% by weight of N,N'-bis(dimethyl)-N-hydroxyethyl-ethylenediamine (DMHEED), in a contact zone, regenerating said amine composition in a regeneration zone, and recycling said regenerated amine composition to said contact zone. The invention also resides in an aqueous solution comprising from about 20% to about 70% by weight of DMHEED. The invention further resides in the addition of DMHEED in an amount of from about 5% to about 30% by weight to compositions or solutions containing other alkanolamines.

Abstract: Liquid absorbing acid gas compounds presenting an improved CO.sub.2 absorption capacity, said absorbing liquid containing one or a plurality of tertiary alkanolamines and a CO.sub.2 absorption activator. The activator is comprised of at least one amino compound selected amongst polyalkylenepolyamines, alkylenediamines or cycloalkylenediamines, the aminoalkylated compounds of heterocycles such as piperazine, piperidine, furan, thiophene, tetrehydrofuran et tetrahydrothiophene, the alkoxyalkylamines and the alkylmonoalkanolamines having an alkyl residue in at least C.sub.2. Application of said absorbant liquid to the deacidification of gases containing CO.sub.2 and optionally other acid gas compounds, particularly H.sub.2 S and/or COS.

Abstract: (a) An alkanolamine solution containing anions, a conductance probe connected through a meter to a recorder and a stirrer are provided in a container, (b) the solution is stirred at a constant rate and metering and recording of the conductance of the alkanolamine solution are initiated, (c) an anion exchange resin in the OH.sup.- form is then introduced to the container in an amount in excess of that required to exchange all anions from the amine solution, (d) the conductance of the alkanolamine solution is monitored until steady state is reached, and (e) the total anion content and the sodium content (if present) are determined from the conductance trace.The process and apparatus may be used to display conductance changes with time and rate of conductance changes with time in order to determine which anions are present in the alkanolamine solution, whether or not sodium is present and the magnitude of conductance values at various time intervals.

Abstract: The corrosion and fouling of metal surfaces in contact with corrosive acid fluids or acid salts in the presence of an aqueous medium is reduced by contacting the surfaces with a composition which comprises (a) an anti-fouling amount of a hydroxyl amine compound of the formulaR.sub.1 R.sub.2 N--OHwherein R.sub.1 and R.sub.2 are independently hydrogen or a hydrocarbyl or inertly substituted hydrocarbyl or both R.sub.1 and R.sub.2 are collectively a divalent hydrocarbyl combined with said nitrogen to form a heterocyclic ring, and (b) a corrosion-inhibiting amount of a reaction product of or a mixture for the purpose of a reaction product of a polyalkylene polyamine and an alkynediol. The polyalkylene polyamine is one that contains from 2-10 amine groups, each separated from another by an alkylene group having from 2-6 carbon atoms. The alkynediol has from 2 to 6 carbon atoms.

Abstract: Monitoring and controlling the reactivation of an alkanolamine solution containing heat-stable salts of such alkanolamine with stronger acid anions and weaker acid anions by contacting the alkanolamine solution (a) with a strong base anion exchange resin which has a high affinity for stronger acid anions (b) contacting the effluent alkanolamine solution from the strong base anion exchange resin with a second strong base anion exchange resin which has an affinity for weaker acid anions (c) measuring and recording the electrical conductance of the effluent solution from the first mentioned anion exchange resin (d) removing the first mentioned anion exchange resin from service when the conductance of the effluent alkanolamine solution from said resin indicates breakthrough of stronger acid anions in said effluent, (e) measuring and recording the electrical conductance of the effluent alkanolamine solution from the second mentioned anion exchange resin (f) removing the second mentioned anion exchange resin from s

Abstract: The present invention provides a method for manufacturing zinc oxide whiskers, whereby zinc powders composed of particles coated with an oxide film, preferably an oxide film having a superior sealing property are, heated for oxidization in an atmosphere containing oxygen.The atmosphere may contain carbon dioxide or steam.The obtained zinc oxide whiskers are formed in a single crystal comprised of a core part and an acicular part spreading in four different directions from the core part.For a baking furnace to obtain zinc oxide whiskers, is employed one that successively forms an atmosphere of a high partial pressure of zinc steam at the source side and an atmosphere of a high partial pressure of oxygen for facilitating formation of whiskers. The zinc oxide whiskers can be controlled in size by selecting the relative ratio of the partial pressure of zinc steam and oxygen.

Abstract: When regenerating gas treating chemicals such as diethanolamine solution, the usual practice is to subject the chemicals to steam stripping. Ultimately such action is ineffective, and it is necessary to discard the chemicals. The waste chemical can be reclaimed by preheating the chemical in a countercurrent heat exchanger, in which heat is recovered from an already processed product; using a still to separate the preheated, partially vaporized chemical from the remainder of the chemicals; i.e. impurities or still bottoms; heating the still bottoms and recycling such bottoms for mixing with the partially vaporized chemical immediately upstream of the still; returning the separated vapor product from the still to the heat exchanger for heating feed chemical; and separating the thus partially condensed product in a separator to yield reclaimed gas treating chemical.

Abstract: A method is disclosed for regenerating spent alkanolamine solutions containing diethanolamine, to restore their acid gas sorption capacity by converting diethanolamine degradation products to the diethanolamine precursor while avoiding substantial thermal decomposition of diethanolamine.

Abstract: The present invention provides a method for purifying alkanolamine solutions which have lost at least a portion of their acid gas sorption capacity due to degradation of the alkanolamine into heat stable salts. Particularly, it has been found that the alkanolamine solution may be rejuvenated by charging the solution to the feed zone of a distillation column reactor at temperatures above about 160.degree. C. and pressure of less than about 2000 mm Hg.

Abstract: The concentration of weak acid and weak base constituents, or their soluble salts, in liquids is determined by passing succeeding samples of constant volume to a separation zone wherein target constituents are volatilized by reagents, then volatilized analytes are stripped from the liquid matrix and carried to a detection zone at a constant flow rate, wherein signals proportional to the variations in individual target analyte concentrations between succeeding samples are generated.

Abstract: An improved acid gas recovery system is provided which has particular application in reducing the incidence of sulfide and other acid gas excursions. The present invention addresses the disadvantages of prior absorption techniques by closely monitoring and maintaining a reaction zone temperature profile within a contactor to improve and control the reaction between acid gas components and the aqueous amine absorbent. The temperature profile is maintained by frequently adjusting relative flow rates of the feed gas and lean amine in the process which in turn reduces the incidence of excursions.

Abstract: A high temperature absorption process for bulk recovery of CO.sub.2 comprises contacting a gaseous mixture containing CO.sub.2, H.sub.2 S, and natural gas with C.sub.3 and heavier components and having a high and variable CO.sub.2 loading, with an amine absorbent solution at a temperature above 220.degree. F. The amine absorbent solution is continuously regenerated in a multiple section flashing so as to reduce the energy requirements for regeneration and thereby making the process more suitable for bulk recovery of CO.sub.2 from gas streams associated with enhanced oil recovery projects employing CO.sub.2 for miscible flood of oil reservoirs.

Abstract: Aqueous alkanolamine solution containing alkali metal salts of anions which form heat stable salts with such alkanolamine is reactivated by contacting the solution sequentially with a basic anion exchange resin to remove such anions and an acidic cation ion exchange resin to remove alkali metal ions.

Abstract: Sulphur dioxide is removed from gas streams by contacting the gas stream with an absorbing medium containing less than about 80 wt. % of water and the spent absorbing medium subsequently is regenerated by removing absorbed SO.sub.2. The absorbing medium comprises amine salt absorbent having at least two amine groups, at least one of which is a salt and at least one of which has a pKa of about 4.5 to 7.3. The absorption is at a temperature of less than about 60.degree. C. The spent absorbing medium is regenerated under conditions such that at least one amine group remains in salt form.

Abstract: A process is disclosed for operating a refinery gas plant such as the unsaturated gas plant of a catalytic hydrocarbon conversion process that results in a reduction of the corrosive effect of acid gases on the gas plant vessels and equipment. The process comprises contacting acidic hydrocarbon feedstreams to an unsaturated gas plant separator zone with lean acid gas absorbing absorbent in an absorbtion zone comprising at least one liquid absorber bed and one vapor absorber bed. The liquid and vapor absorber beds are located upstream of the separator zone. The feedstreams to the gas plant comprise unstabilized, or wild, liquid gasoline and liquid and vapor output streams from the liquid-vapor separator for inter-stage wet gas compressor of the conversion process main fractionator. Accordingly, these feedstreams are deacidified before separation in the USGP deethanizer-absorber, sponge absorber, and debutanizer. This also eliminates the need for deacidification of the gas plant product stream.

Abstract: Spent aqueous alkanolamine solution containing free alkanolamine, alkali metal salts of anions which form heat stable salts with such alkanolamine and heat stable alkanolamine salts is reactivated by contacting the solution with an acidic cation ion exchange resin to remove alkali metal cations and alkanolamine cations resulting from (1) protonation of free alkanolamine with hydrogen on the resin and (2) the alkanolamine salts, followed by eluting the resin with aqueous ammonia to preferentially displace alkanolamine from the resin and thereafter eluting the resin with a dilute mineral acid to displace the ammonia, metal cations and any remaining alkanolamine. The displaced alkanolamine is recovered for reuse. The aqueous ammonia may also be recovered for reuse.

Abstract: CO.sub.2 and, if necessary, H.sub.2 S are removed from a gas which contains CO.sub.2 and may contain H.sub.2 S with an absorption liquid by a process in which the gas which contains CO.sub.2 and may contain H.sub.2 S is treated in an absorption zone with the absorption liquid, the treated gas is removed from the absorption zone, the absorption liquid which is obtained from the absorption zone and is laden with CO.sub.2 and may be laden with H.sub.2 S is then regenerated in that the said absorption liquid is let down in one or more let-down stages and a let-down gas is taken off at the top of the first let-down stage or, in the case of a plurality of let-down stages, at the top of one or more of the first to penultimate let-down stages, and the partially regenerated absorption liquid obtained from the last let-down stage is, if required, fed to a stripping zone for further regeneration, one or more acid gas streams which contain the CO.sub.2 and may contain H.sub.

Abstract: Gases containing CO.sub.2 and/or H.sub.2 S in a first absorption stage, at from 40.degree. to 100.degree. C., with an aqueous absorption liquid containing from 20 to 79% by weight of methyldiethanolamine, the gas obtained at the top of the first absorption stage is fed to a second absorption stage in which, it is treated at from 30.degree. to 90.degree. C. with an aqueous absorption liquid which contains from 20 to 79% by weight of methyldiethanolamine and has a lower content of CO.sub.2 and/or H.sub.2 S than the absorption liquid fed into the first absorption stage, the treated gas is taken off at the top of the second absorption stage, the aqueous absorption liquid obtained at the bottom of the second absorption stage and preladen with CO.sub.2 and/or H.sub.2 S is fed to the top of the first absorption stage, the aqueous absorption liquid obtained in the lower part of the first absorption stage and laden with CO.sub.2 and/or H.sub.

Abstract: Hydrogen sulfide is separated from the dimethyl ether of tetraethylene glycol through a membrane of hydrolyzed cellulose.

Abstract: A method of removing hydrosulfide from a crude gas produced by partial oxidation of carbon-containing material comprises the steps of treating a gas at a temperature between 10.degree. and 60.degree. C. with a suitable absorption solution, regenerating the absorption solution loaded durhg the treating, and cooling the crude gas which has been precleaned and pre-cooled to a temperature of 110.degree.-150.degree. C. before entering the absorption column, in a stepped manner in indirect heat exchange, the cooling including supplying the gas first through a reboiler of a desorption column and then through a heat exchanger which serves for preheating of the loaded absorption solution.

Abstract: Aqueous alkanolamine solution containing alkali metal salts of anions which form heat stable salts with such alkanolamine is reactivated by contacting the solution sequentially with a basic anion exchange resin to remove such anions and an acidic cation ion exchange resin to remove alkali metal ions.

Abstract: A process for the removal of carbon dioxide, hydrogen sulfide and alkyl mercaptans from a hydrocarbon-containing feed gas:(a) contacting the feed gas with an adsorbent capable of removing hydrogen sulfide and alkyl mercaptans from the feed gas at effective conditions to produce a treated gas having reduced concentrations of hydrogen sulfide alkyl mercaptans;(b) contacting the treated gas with a liquid medium capable of removing carbon dioxide hydrogen sulfide and alkyl mercaptans from the treated gas at effective conditions to produce a product gas having reduced concentrations of carbon dioxide hydrogen sulfide and alkyl mercaptans;(c) contacting a spent absorbent laden with hydrogen sulfide and alkyl mercaptans with a normally liquid fraction at effective desorption conditions to produce a regenerated adsorbent and a regeneration effluent having increased concentrations of hydrogen sulfide and alkyl mercaptans; and(d) utilizing the regenerated adsorbent as at least a portion of the adsorbent in step (a).

Abstract: Method and devices for the selective removal of H.sub.2 S from an H.sub.2 S-containing gas by contacting the gas in an absorption column with an H.sub.2 S-selective absorbent liquid and transferring the H.sub.2 S-charged absorbent liquid to the upper part of a second column. The charged absorbent liquid then travels to a regeneration zone at the bottom of the column, where it is heated to a temperature at which the absorbent liquid is vaporized and the H.sub.2 S is released.The regeneration zone temperature causes the absorbent liquid vapor to strip the H.sub.2 S back to the upper part of the column where it forms an equilibrium with the H.sub.2 S-charged absorbent liquid at a temperature not more than 30.degree. C. higher than the injection temperature of the absorbent liquid in the absorption column, which equilibrium temperature is maintained by the temperature in the regeneration zone. The H.sub.2 S-enriched vapor formed at the equilibrium point is then tapped.

Abstract: An improved process is provided for the removal and recovery of acidic gases contained in mixed gas streams. The improvements comprise cooling a process regenerated aqueous alkanolamine solution containing an alkanolamine concentration ranging up to about 20 percent by weight to a temperature ranging up to about 35.degree. C. and introducing said cooled regenerated solution into an absorption zone to contact a mixed gas stream containing acidic gases and wherein the regenerated aqueous alkanolamine solution remains essentially at the temperature to which it is cooled throughout a substantial portion of the absorption zone.

Abstract: A process for the selective removal of sulfur-containing gases from industrial gases or waste gases by treatment of gases with basic substances, characterized in that the basic substances are carrier materials containing tertiary amino groups corresponding to the following formula: ##STR1## in which m and n individually are 1 or 2,x and y individually are from 0 to 10 and preferably 0 to 2,R and R' individually are hydrogen or alkyl andR" is hydrogen or methyl.

Abstract: The invention is a process for removing H.sub.2 S, CO.sub.2 and mercaptans from a gas stream by liquid absorption using an absorbent wherein the mercaptans are absorbed at a high pressure and low temperature in a secondary absorption zone and separated from the absorbent by reduction of pressure after heating. The absorbent after reduction of pressure can be recycled to the absorpiton zone. The H.sub.2 S and CO.sub.2 are absorbed at a higher temperature than the mercaptans and are stripped from the absorbent in a regeneration zone after a reduction in pressure. The absorption zone requires two separate zones where the gas being treated passes from the high temeprature absorption zone to the low temperature zone where the mercaptans are removed.

Abstract: Method for the selective removal of H.sub.2 S from a H.sub.2 S-containing gas by operating in a single column (1) comprising an upper absorption zone (11) and a lower regeneration zone (12) separated by a medial enrichment zone (17). A selective absorbing and regeneratable liquid capable of absorbing H.sub.2 S is introduced at the upper portion of the column and flows successively into the zones (11) and (17) and finally into (12). The absorbing liquid meets the gas to be treated, which is injected through a conduit (9), in the zone (11) while the regenerated absorbing liquid is tapped at the bottom (4) of the column and brought back through a conduit (5) into said zone (11). At the head (2) of the column, a gas having a reduced content of H.sub.2 S is discharged and by means of a system (18) provided in the zone (17) an acid gas fraction rich in H.sub.2 S is tapped. Application to the production of a highly H.sub.2 S enriched gas effluent from a gas containing H.sub.2 S and an appreciable quantity of CO.sub.

Abstract: A process for the purification of a gas stream containing impurities comprising (i) passing the gas stream through an aqueous solution of stabilized monoethanolamine or diethanolamine in such a manner that the impurities are absorbed into the monoethanolamine solution or diethanolamine solution to form a rich solution and (ii) regenerating the monoethanolamine or diethanolamine solvent from the rich solution so as to remove the impurities, (iii) recycling the solvent into the aqueous solution in a closed loop and introducing a stabilizer into the recirculating solvent solution in an amount of about 4 to about 25 percent by weight based on the total weight of solution, the stabilizer being methyldiethanolamine.