Abstract: The selective removal of H.sub.2 S gas from a normally gaseous mixture containing H.sub.2 S and CO.sub.2 is accomplished by contacting the gaseous mixture with an absorbent solution comprising a diaminoether wherein at least one amino group is a tertiary amine whereby H.sub.2 S is selectively absorbed from the mixture.

Abstract: 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.

Abstract: The present invention relates to an alkaline salt promoter system which includes N-secondary butyl glycine and its use in acid gas scrubbing processes.

Abstract: 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.

Abstract: The selective removal of H.sub.2 S gas from a normally gaseous mixture containing H.sub.2 S and CO.sub.2 is accomplished by contacting the gaseous mixture with an absorbent solution comprising a di-secondary aminoether wherein each amino group has a severely sterically hindered secondary amino moiety whereby H.sub.2 S is selectively absorbed from the mixture.

Abstract: The selective removal of H.sub.2 S gas from a normally gaseous mixture containing H.sub.2 S and CO.sub.2 is accomplished by contacting the gaseous mixture with an absorbent solution comprising a tertiary amino azabicyclic alcohol whereby H.sub.2 S is selectively absorbed from the mixture.

Abstract: An improved method for removing acidic gases from a gas stream containing the acidic gases is disclosed in which a corrosion inhibitor comprising a mixture of salts of antimony and molybdenum is added to an amine promoted alkaline salt scrubbing solution.

Abstract: The selective removal of H.sub.2 S gas from a normally gaseous mixture containing H.sub.2 S and CO.sub.2 is accomplished by contacting the gaseous mixture with an absorbent solution comprising a severely sterically hindered secondary aminoether alcohol having a cumulative .sup.- -E.sub.s value (Taft's steric hindrance constant) greater than about 1.75 whereby H.sub.2 S is selectively absorbed from the mixture.

Abstract: 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.

Abstract: The selective removal of H.sub.2 S gas from a normally gaseous mixture containing H.sub.2 S and CO.sub.2 is accomplished by contacting the gaseous mixture with an absorbent solution comprising a severely sterically hindered secondary amino compound having a cumulative .sup.- E.sub.s value (Taft's steric hindrance constant) greater than about 1.75 whereby H.sub.2 S is selectively absorbed from the mixture.

Abstract: The corrosion of iron and steel surfaces by an aqueous alkanolamine conditioning solution used to remove CO.sub.2 from a gas stream is effectively inhibited by a combination of a vanadium containing ion and a di- or triamine. A surprising fact is that some of the amine co-inhibitors have been identified by others in the art as promoting ferrous metal corrosion.

Abstract: A process for the treatment of a gas mixture containing methane and light hydrocarbons is disclosed, the process being characterized in that the gas mixture is treated in two steps consecutively with two different liquid mixtures, each of which contains a physical and chemical absorbent, in the first step H.sub.2 S being selectively removed, in the second step the remaining acid gases being virtually completely removed.

Abstract: The corrosion of iron and steel surfaces by an aqueous alkanolamine conditioning solution used to remove CO.sub.2 from a gas stream is effectively inhibited by a combination of a vanadium containing ion and a soluble cobalt salt. This system allows the use of higher amine concentrations which in turn allows a higher carbon dioxide loading with low corrosion thereby improving the energy efficiency of the gas sweetening process.

Abstract: Decarbonation of gases with solutions of alkali metal carbonates and with alkanolamine solutions is improved by exploiting the heat of the vapors exiting the head of the alkanolamine solution regeneration column and also the heat of fluids condensed at the head of the regeneration column for the alkali metal carbonate solution. A very favorable heat balance is achieved and considerable power savings.

Abstract: A process for the recovery of carbon dioxide from a flue gas stream containing residual oxygen is disclosed. A combustible fuel, such as methane, is admixed with the flue gas stream and the flue gas stream is then passed into a combustion zone in which it may be contacted with a catalyst which promotes the consumption of the residual oxygen in a combustion reaction. Preferably, the heat liberated in the combustion reaction is recovered for use in heating flue gas to combustion supporting conditions and in downstream carbon dioxide recovery steps. The purpose of the combustion reaction is to lower the oxygen content of the flue gas stream, which is then contacted with a lean carbon dioxide absorbing amine solution. The low oxygen content reduces the degradation of the amine solution and the corrosiveness of the amine solution thus allowing the use of high strength amine solutions and very high absorbent liquid loadings.

Abstract: In the process for reducing the total sulfur content of a high CO.sub.2 -content feed gas stream, the feed gas is first passed to an absorption column. The unabsorbed, high CO.sub.2 -content gas is then routed to a reduction step where it is combined with Claus off-gases and the sulfur compounds are reduced to H.sub.2 S. The treated gas is then passed to a second absorption column and the unabsorbed gas is vented to the atmosphere. The fat solvent from both absorption columns is stripped in a common stripper and the stripped gas is passed to a Claus unit for conversion to elemental sulfur.

Abstract: A process for scrubbing acid gases in which carbon dioxide and hydrogen sulfide, for example, are scrubbed from gas mixtures which also contain polymerizable organic components, in which an aqueous alkanolamine, such as ethanolamine, is used as the scrubbing liquid. The scrubbing liquid is heated, regenerated, cooled and returned to the scrubber and the polymerizable component or the polymer formed therefrom is removed by treating the scrubbing liquid with an organic solvent which is water immiscible. The extraction treatment by the organic solvent, according to the invention, is carried out after the heating and before the regeneration of the charged scrubbing liquid at a temperature of the latter which is just below the boiling point of the liquid mixture formed by the scrubbing liquid and the organic extracting solvent.

Abstract: The invention concerns a process for the purification of residual industrial gases containing a small quantity of H.sub.2 S, SO.sub.2, CS.sub.2, COS, or possibly sulfur vapor, as well as large amounts of H.sub.2 O, CO.sub.2 and N.sub.2 in which the residual gases are first subjected to a catalytic reduction in which all the sulfur compounds are transformed into H.sub.2 S, and thereafter washed by an aqueous amine solution before being burnt and discarded into the atmosphere, while the aqueous amine solution is regenerated by heating and the gases given off, comprising H.sub.2 S and CO.sub.2, are returned to the sulfur manufacturing plant.The process is characterized in that the temperature of the gas to be treated is permanently maintained at a level higher than the dew-point of the water contained in the gases at all points of the process, thereby insuring that substantially all H.sub.2 O contained in the residual gases is discarded into the atmosphere.

Abstract: An aqueous solution containing from 0.81 to 1.3 moles of piperazine per liter is used as a washing agent for removing impurities such as H.sub.2 S, CO.sub.2 and COS from gases. Piperazine can also be used, in amounts of up to 0.8 mole per liter, together with physical or chemical solvents, to accelerate the absorption of H.sub.2 S, CO.sub.2 and COS. The washing process is used for natural gases, coke-oven gases, gases from the gasification of coal and synthesis gases, of any origin.

Abstract: Hydrogen sulfide and carbonyl sulfide are removed from a gas stream in a staged procedure characterized by conversion of the hydrogen sulfide to produce sulfur in aqueous solution, hydrolysis of the carbonyl sulfide remaining in the gas stream to produce hydrogen sulfide and carbon dioxide, and removal of the hydrogen sulfide from the gas stream.

Abstract: An improvement in a process of regenerating a hydrocarbon laden water miscible high boiling organic solvent obtained by scrubbing a hydrocarbon-containing gas with said water miscible high boiling organic solvent at normal temperature and super atmospheric pressure, wherein the laden solvent is regenerated by flashing, heating and/or stripping, cooled and recycled to the scrubbing step, the improvement comprising:A. adding liquid hydrocarbons to at least a part of said regenerated solvent and thereafter extracting the resultant mixture in the presence of water whereby to obtain a hydrocarbon rich phase and an aqueous phase containing said solvent;B. separating said aqueous phase from said hydrocarbon rich phase and recycling said aqueous phase to the regeneration step; andC. withdrawing said hydrocarbon rich phase.

Abstract: A process is disclosed for inhibiting or eliminating foams and bubbles produced in the course of treating acidic gases with an aqueous solution. Defoaming is effected by the use of a modified silicone compound having the general formula ##STR1## where R.sub.1 -R.sub.8 are organic residues of 1-10 carbons, and n is an integer, and characterized by part of R.sub.1 -R.sub.8 being substituted by a group of the general formula--R.sub.9 --OHwhere R.sub.9 is a hydrocarbon or organic residue of 1-10 carbons; or characterized by part of R.sub.1 -R.sub.8 being substituted by a group of the general formula--NR.sub.10 R.sub.11where R.sub.10 and R.sub.11 are either hydrogen or hydrocarbon or organic residue of 1-10 carbons.

Abstract: This invention relates to a method for treating residue gases proceeding from units applying the Claus reaction for the removal of sulphur and having been subjected to a conversion of the sulphur compounds into sulphuretted hydrogen.This method consists in that, prior to absorption of the sulphuretted hydrogen by a selective solvent in aqueous solution, the gases to be treated are cooled to a temperature so selected as to condense the water contained in the gases to form an aqueous effluent which is thereafter injected into the circuit of the selective solvent.

Abstract: A method for regenerating a spent alkanolamine absorbing solution containing absorbed H.sub.2 S and CO.sub.2 in two desorption stages to produce two separate acid gas streams. The first acid gas stream that contains substantially all of the H.sub.2 S is sent to a sulfur recovery system and the second acid gas stream that is primarily CO.sub.2 is vented to the atmosphere. The desorption stages are connected in series and both are operated at substantially the same above-atmospheric pressure within the range of 8-12 psig (1.54-1.82 atm abs).

Abstract: A vapor-liquid contacting tray wherein a perforated portion of the tray member forms an active surface area for vapor-liquid contact in the interior of the tray member. The active surface area portion of the tray member is circumscribed by an imperforate peripheral portion of the tray member with a width of from 0.05 to 0.35 times the radius of the tray. The disclosed tray provides upwardly directed laminar jetting of liquid over the tray perforation openings for high selectivity vapor-liquid contacting and has particular utility in the absorption of hydrogen sulfide from a gas mixture containing hydrogen sulfide and carbon dioxide.

Abstract: The invention concerns a process for the purification of residual industrial gases containing a small quantity of H.sub.2 S, SO.sub.2, CS.sub.2 COS, or possibly sulfur vapor, as well as large amounts of H.sub.2 O, CO.sub.2 and N.sub.2 in which the residual gases are first subjected to a catalytic reduction in which all the sulfur compounds are transformed into H.sub.2 S, and thereafter washed by an aqueous amine solution before being burnt and discarded into the atmosphere, while the aqueous amine solution is regenerated by heating and the gases given off, comprising H.sub.2 S and CO.sub.2, are returned to the sulfur manufacturing plant.The process is characterized in that the temperature of the gas to be treated is permanently maintained at a level higher than the dew-point of the water contained in the gases at all points of the process, thereby insuring that substantially all H.sub.2 O contained in the residual gases is discarded into the atmosphere.

Abstract: Sour industrial gases containing carbon dioxide and hydrogen sulfide are treated with amines to remove the CO.sub.2 and H.sub.2 S. The amine absorbent containing or loaded with H.sub.2 S and CO.sub.2 is regenerated and the off-gas containing concentrated amounts of H.sub.2 S and CO.sub.2 is treated in a second amine absorber to produce an amine absorbent loaded with H.sub.2 S. This amine is then regenerated to provide an off-gas containing a high ratio of H.sub.2 S to CO.sub.2 which makes it suitable for use as the feed gas to a sulfur recovery unit such as a Claus plant. The process is automatically controlled so that the concentration of H.sub.2 S in the second amine absorber is built up to and controlled at a desired set point so that the off-gas has the required H.sub.2 S/CO.sub.2 ratio.

Abstract: Disclosed is the method of defoaming an aqueous amine gas purification scrubbing solution by stripping gaseous contaminants from the scrubbing solution and then passing a side stream of from about 10% to about 20% of the scrubbing solution through a carbon filter.

Abstract: 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.

Abstract: A method for removing an acidic component from a gaseous mixture by contacting the gaseous mixture in an absorber with an absorbing solution which removes substantial quantities of the acidic component. The gaseous mixture is then passed through an adsorption zone containing an adsorbent which removes additional quantities of the acidic component. The adsorbent is regenerated by passing regenerating solution through the adsorption zone. In a preferred embodiment, the composition of the regenerating and absorbing solutions are substantially the same and include an amine. This solution may be passed through the adsorption zone to regenerate the adsorbent and then into the absorber to remove acidic components from the gaseous mixture therein.

Abstract: A process for the removal of hydrogen sulfide from a gas stream is described, the process being characterized by removal of organic sulfur compounds also present in the stream and by an improved solvent flow.

Abstract: Carbon dioxide containing acidic gases are substantially removed from a normally gaseous mixture by a process comprising contacting the normally gaseous mixture with an aqueous amine solution, wherein the amine consists of at least about 50 mol % of a sterically hindered amino alcohol and at least about 10 mol % of a tertiary amino alcohol, wherein said sterically hindered amino alcohol contains at least one secondary amino group which is part of a ring and is attached to either a secondary or tertiary carbon atom or a primary amino group attached to a tertiary carbon atom. The coaction of the sterically hindered amino alcohol and the tertiary amino alcohol provide an increase in the amount of carbon dioxide containing acidic gases absorbed compared to the use of the sterically hindered amines alone and lowers the heat of reaction.

Abstract: In a gas purification process wherein hydrogen sulfide is adsorbed by an alkanolamine solution in an absorption zone and desorbed in a regenerating column, the improvement comprising reducing corrosion in the overhead section of the column by introducing into the overhead section of the regenerating column an effective amount of ammonia scrubber bottoms liquid.

Abstract: 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.

Abstract: A continuous process for acid gas removal from process gas streams by contact with an aqueous alkanolamine solution such as MEA wherein the temperature of the MEA solution is controlled by placing an intercooler at the lower end of the absorption column such that the temperature of the down-coming MEA solution is cooled to allow increased mole loading of acid gas in the solution, but is not so cooled that the mass transfer rate of the acid gas from the process gas to the MEA solution is slowed to an unacceptable level. The lower temperature highly loaded MEA solution is then passed to a heat exchanger-flash-heat exchanger arrangement where the temperature is increased to provide satisfactory flash efficiency and then heated again prior to introduction into the stripper to reduce the sensible heat duty in the stripper.

Abstract: Impurities such as hydrogen sulfide and carbon dioxide are removed from fluids such as natural gas, synthesis gas or liquid or gaseous hydrocarbons by contact with an aqueous alkanolamine solution which absorbs said impurities from the fluid. The resultant spent impurity-enriched absorbent amine stream containing the absorbed impurities is split into two streams; one stream being routed directly to the top of an amine regenerator column and the second stream being routed to a heat exchanger where it is heated en route to an intermediate point of the regenerator column by heat exchange with the hot regenerated solution coming from the bottom of the regenerator column. The spent amine stream which is passed without prior heating directly to the top of the regenerator column is heated by condensing steam in the column which would normally escape therefrom, thereby reducing the amount of "saturation" steam which is lost from the system.

Abstract: Hydrogen sulfide is removed from a mixture of gases including carbon dioxide by passing the mixture over an immobilized liquid membrane in intimate contact with a hydrophobic, microporous gas, permeable barrier and absorbing in a liquid solution hydrogen sulfide passing through the membrane. In a sweep of hot carbonate solution, a nearly stagnant boundary layer adjacent the gas permeable barrier absorbs acid gases by reaction and diffusion, maintaining low hydrogen sulfide partial pressure at the outlet side of the barrier. Alternatively, the sweep may comprise an aqueous solution containing a redox agent which converts absorbed hydrogen sulfide into sulfur, or an ethanol amine solution. The apparatus exhibits low permeability to carbon dioxide and high permeability to hydrogen sulfide.

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

Abstract: A copper based corrosion inhibitor composition and a method for employing the same to prevent corrosion of metal in contact with acid-gases, i.e., hydrogen sulfide, carbonyl sulfide and carbon dioxide. Copper, or a copper compound and sulfur or a sulfur compound, is maintained in solution in contact with the metal under conditions of operation, particularly the thermal regeneration, which provide copper ions and sulfur atoms, particularly polysulfide moieties at the surface of the metal, e.g. copper sulfide is dissolved in an aqueous alkanolamine, monoethanolamine, solution used as an absorbent for acid-gas removal from sour-gas. The copper and sulfur moieties may be formed in situ or prepared and added in solution. The inhibitor has particular utility in protecting metal surfaces which are subject to corrosion as an incidence of the acid-gas content of either natural or synthetic gases.

Abstract: This specification discloses a method and apparatus for producing and recovering alkanolamine from a mixture containing oxazolidone by hydrolyzing the mixture containing oxazolidone.

Abstract: 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.

Abstract: Novel process for removing polymer from aqueous absorbent solutions used to contact organic gas-containing gas streams comprising the steps of adjusting the polymer-containing aqueous absorbent solutions to a pH of not more than about 8.5, preferably not more than about 7.5, for example, about 6.0 to about 8.5, preferably about 7.0 to about 7.5, and removing the polymer from the resulting solutions by decantation and/or filtration. The novel process is particularly applicable to the system of removing acid gas from hydrocarbon-containing feed gases which contain one or more polymerizable components wherein the feed gas is contacted with an aqueous absorbent solution which absorbs the acid gas and, thereafter, the absorbent solution is stripped to rid it of said acid gas. The adjustment of pH can be accomplished by increasing the acid gas loading in the aqueous absorbent or by adding an acid, preferably one which will not form a heat stable salt with the absorbent. The pH adjustment, e.g.

Abstract: The corrosion of iron and steel by an aqueous sour gas conditioning solution used to remove CO.sub.2 from a gas stream is effectively inhibited by a combination of a quaternary pyridinium salt and an organic thioamide, a water-soluble sulfide or a water-soluble thiocyanate.

Abstract: Carbon dioxide containing acidic gases are substantially removed from a normally gaseous mixture by a process comprising contacting the normally gaseous mixture with an aqueous amine solution, wherein the amine consists of at least about 50 mol % of a sterically hindered amino alcohol and at least about 10 mol % of a tertiary amino alcohol, wherein said sterically hindered amino alcohol contains at least one secondary amino group which is part of a ring and is attached to either a secondary or tertiary carbon atom or a primary amino group attached to a tertiary carbon atom. The coaction of the sterically hindered amino alcohol and the tertiary amino alcohol provide an increase in the amount of carbon dioxide containing acidic gases absorbed compared to the use of the sterically hindered amines alone and lowers the heat of reaction.

Abstract: The corrosion of iron and steel by an aqueous sour gas conditioning solution used to remove CO.sub.2 and H.sub.2 S from a gas stream is effectively inhibited by a combination of a quaternary pyridinium salt and a lower alkylenepolyamine or corresponding polyalkylenepolyamine.

Abstract: The corrosion of iron and steel by an aqueous sour gas conditioning solution used to remove CO.sub.2 from a gas stream is effectively inhibited by a combination of a quaternary pyridinium salt and an organic thioamide or water-soluble thiocyanate. The addition of a small amount of a water-soluble cobalt salt to the inhibitor combination improves its effectiveness.

Abstract: 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 mixture comprised of at least about 50 mol % of a sterically hindered amine and at least about 10 mol % of a tertiary amino alcohol, wherein said sterically hindered amine contains at least one secondary amino group which is part of a ring and is attached to either a secondary or tertiary carbon atom or a primary amino group attached to a tertiary carbon atom, 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. The coaction of the sterically hindered amine and the tertiary amino alcohol in conjunction with the solvent provides an increase in the amount of CO.sub.2 containing acidic gases absorbed compared to the use of the same sterically hindered amines alone and lowers the heat of reaction.

Abstract: An aqueous organic amine acid gas scrubbing system, particularly an aqueous N-methyldiethanolamine or diethanolamine acid gas scrubbing system having incorporated therein (1) a compound or mixture of compounds having the formula ##STR1## wherein n is an integer from 1 to 3, m is an integer from 2 to a number sufficient to yield a molecular weight of about 800, R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently selected from the group consisting of --H, --C.sub.n' H.sub.2n' OH, --C.sub.n' H.sub.2n'+1, --C.sub.n' H.sub.2n' N(R.sub.3)R.sub.4 wherein n' is an integer from 1 to 2 and wherein R.sub.1 -R.sub.3 and R.sub.2 -R.sub.4 may be joined to form cyclic amines when n is 2; said compound being present in about 10 to about 2000 parts per million parts of treating solution; (2) copper or a copper ion yielding compound in from 0 to 1000 ppm; and (3) sulfur or a sulfur atom yielding compound in from 0 to 1000 ppm.

Abstract: 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.

Abstract: A continuous process for acid gas removal such as the removal of carbon dioxide, from a feed mixture of process gas and acid gas which comprises introducing the gaseous feed mixture to an absorption zone at an absorption zone inlet temperature in the range of about 35.degree. C. to 150.degree. C., treating the gaseous feed mixture in the absorption zone with an aqueous solution of alkanolamine under specified conditions, the absorption zone inlet temperature for the solution being in the range of about 30.degree. C. to about 75.degree. C., passing the aqueous solution of alkanolamine having acid gas absorbed therein to a stripping zone at an inlet temperature essentially the same as the absorption zone outlet temperature for said solution, removing solution from the bottom of the stripping zone at a bottoms outlet temperature in the range of about 100.degree. C. to about 150.degree. C.