Abstract: A system and a method for increasing the selectivity of H2S absorption in an aqueous amine treating processes for streams containing high CO2:H2S ratio mixtures in an absorption column by maintaining the temperature in the absorption column by withdrawing, cooling and returning cooled aqueous amine to the column at at least one location intermediate the sour gas inlet to the column and the lean gas outlet from the column.

Abstract: In a decarbonation process for removing carbon dioxide from a carbon dioxide-containing gas with the use of an amine compound-containing absorbing solution, an amine compound accompanying a decarbonated exhaust gas is efficiently recovered in the following manner: A water washing section is constituted in two stages, a first-stage water washing section 64 and a second-stage water washing section 65. In these water washing sections, recovery of the amine compound accompanying the decarbonated exhaust gas is performed sequentially. Regeneration tower refluxed water is supplied as washing water to the second-stage water washing section 65. Washing water is withdrawn from the second-stage water washing section 65 and supplied to the first-stage water washing section 64. Demisters 83, 84 and 85 are provided at outlets of a carbon dioxide absorption section 73, the first-stage water washing section 64 and the second-stage water washing section 65.

Abstract: A process is described for removing acid gases from a gas stream in which an acid-gas-containing gas stream in which the sum of the partial pressures of the acid gases does not exceed 1 500 mbar is brought into contact with an aqueous absorbent in an absorption step and an absorbent is used which contains methyldiethanolamine and piperazine at a concentration of at least 8% by weight of the absorbent, an acid-gas-depleted gas stream and an acid-gas-loaded absorbent being obtained.

Abstract: The disclosure concerns a process for removing mercaptans from fluid streams comprising same, especially from hydrocarbon gas streams, for example natural gas, synthesis gas from heavy oil or heavy residues or refinery gas, or else from liquid hydrocarbons, for example LPG (liquefied petroleum gas). The invention comprises intimately contacting the fluid stream in an absorption or extraction zone with a scrubbing liquor comprising at least one aliphatic alkanolamine of 2-12 carbon atoms, the amount of wash liquor being supplied to the absorption or extraction zone being sufficient to remove at least CO2 and H2S essentially completely from the fluid stream, and separating the substantially decontaminated fluid stream and the contaminated wash liquor and discharging them from the absorption zone.

Abstract: Sour natural gas is processed to remove the sulfur compounds and recover C4+/C5+ hydrocarbons by scrubbing the gas with an amine solution to remove most of the sulfur, followed cooling the gas to remove C4+/C5+ hydrocarbons and more sulfur compounds as liquid condensate to produce a gas having less than 20 vppm of total sulfur. The condensate is sent to a fractionator to recover the C4+/C5+ hydrocarbons. The sulfur and hydrocarbon reduced gas is contacted first with zinc oxide and then nickel, to produce a gas having less than 10 vppb of total sulfur which is passed into a synthesis gas generating unit to form a very low sulfur synthesis gas comprising a mixture of H2 and CO. This synthesis gas is useful for hydrocarbon synthesis with increased life of the hydrocarbon synthesis catalyst and greater hydrocarbon production from the hydrocarbon synthesis reactor. Contacting the synthesis gas with zinc oxide further reduces the sulfur content to below 3 vppb.

Abstract: A process for removing CO2 from a combustion gas which comprises bringing a combustion gas containing oxygen and CO2 and a CO2 absorbent solution into contact at the atmospheric pressure, thereby allowing the CO2 absorbent solution to absorb CO2 from the combustion gas, and, in the ensuing step, heating the absorbent solution that has absorbed CO2 to liberate CO2 and regenerate the CO2 absorbent solution, and circulating the regenerated solution for reuse. An aqueous solution of a hindered amine selected from the group consisting of 2-amino-2-methyl-1-propanol (AMP), 2-(ethylamino)-ethanol (EAE), 2-(methylamino)-ethanol (MAE), and 2-(diethylamino)-ethanol (DEAE) is used as the CO2 absorbent solution, and carbon steel is used in building the members of the equipment that contact the aqueous hindered amine solution. The absorbent solution contains cupric carbonate which is a corrosion inhibitor.

Abstract: Within the scope of a process using two absorption sections for treating a natural gas containing CO2 and/or H2S, as well as mercaptans, COS and/or CS2, the present invention aims to wash the gaseous hydrocarbons desorbed upon expansion of the solvent from the first absorption section with the solvent from the second absorption section.

Abstract: A recovery plant for recovery of a gaseous component, such as carbon dioxide, from a process gas, such as the exhaust from a combustion turbine, has an absorber (110) employing a lean solvent (126) in an upper section of the absorber and a semi-lean solvent (172) in a lower section of the absorber. A regenerator (120) extracts the gaseous component from the rich solvent (117) thereby producing a regenerated lean solvent (126) and a semi-lean solvent (127). A solvent flow control element (170) combines at least a part of the semi-rich solvent (118) from the upper section of the absorber with the semi-lean solvent (127) from the regenerator to form a mixed solvent (171), and a cooler (112) cools the mixed solvent that is subsequently fed into the lower section of the absorber (110). By cooling the mixed solvent prior to entry into the absorber, the thermal energy required to remove the carbon dioxide from the exhaust gas can be reduced.

Abstract: A method for removing residual VOC components from a fluid stream used in the sweetening of sour gas at gas processing plants. In a retrofit configuration, the method includes interposing a supplemental VOC removal station after a primary VOC removal station in an absorbent fluid stream. The absorbent fluid stream incorporates fluid into which sour gas components and VOC have been absorbed from a treated gas stream such as produced natural gas. The primary VOC removal station is configured to remove an initial portion of the absorbed VOC from the absorbent fluid stream. The supplemental VOC removal station is configured to liberate a portion of residual absorbed VOC remaining in the absorbent fluid stream downstream from the primary VOC removal station. Further, the supplemental VOC removal station is configured to avoid liberating absorbed sour gas components from the absorbent fluid stream.

Abstract: A column of solvent containing foaming contaminants is provided. Gas is educted into the solvent in the column so as to generate foam in the column. The gas is educted into the column independently of the input flow of solvent into the solvent using a pumparound arrangement with the solvent. Foam generation continues so as to push the foam up in the column, wherein much of the solvent that is in the foam is allowed to drain back down into the column. The foam passes through concentrators which increase the residency time of the foam in the column to further dry the foam and to create larger bubbles. The drier foam is pushed out of the column and into a container. The foam is broken up into gas and the liquid foaming contaminants. The gas is recirculated for injection into the column even after foaming has stopped. The foaming contaminants are concentrated at the surface level of the solvent in the column. These contaminants are removed from the column.

Abstract: A method for controlling absorbent at a decarboxylation facility with an absorption tower having an amine recovery section and a regeneration tower, including controlling a temperature controller for controlling a temperature of circulating water forwarded to the amine recovery section of the absorption tower by a controller which controls a liquid level at the bottom of the absorption tower, whereby the concentration of amine in the absorbent is regulated.

Abstract: There are disclosed a method for removing CO2 from a combustion exhaust gas which comprises the step of bringing the combustion exhaust gas under atmospheric pressure into contact with an aqueous solution of a hindered amine selected from the group consisting of 2-amino-2-methyl-1-propanol, 2-methylaminoethanol, 2-ethylamino-ethanol and 2-piperidineethanol; and another method for removing carbon dioxide from a combustion exhaust gas which comprises the step of bringing the combustion exhaust gas under atmospheric pressure into contact with a mixed aqueous solution of 100 parts by weight of an amine compound (X) selected from the group consisting of 2-amino-2-methyl-1, 3-propanediol, 2-amino-2-methyl-1-propanol, 2-amino-2-ethyl-1, 3-propanediol, t-butyldiethanolamine and 2-amino-2-hydroxymethyl-1,3-propanediol; and 1-25 parts by weight of an amine compound (Y) selected from the group consisting of piperazine, piperidine, morpholine, glycine, 2-methylamino-ethanol, 2-piperidineethanol and 2-ethylaminoethanol.

Abstract: Carbon dioxide is recovered from a feed stream whose pressure is up to 30 psia by preferentially absorbing carbon dioxide from said feed stream into a liquid absorbent fluid, pressurizing and heating the resulting stream to a pressure sufficient to enable the stream to reach the top of the stripper at a pressure of 35 psia or greater, and stripping carbon dioxide from said stream in a stripper operating at a pressure of 35 psia or greater and recovering from said stripper a gaseous carbon dioxide product stream having a pressure of 35 psia or greater.

Abstract: The invention provides a solid sorbent composition for removal of carbon dioxide and other acidic components from a gaseous stream, said composition being a product of a reaction of a mixture of at least one liquid absorbent material selected from the group consisting of amino alcohols and amino alcohols in combination with a sodium carbonate, a sodium bicarbonate, a potassium carbonate, a potassium bicarbonate and mixtures thereof, with at least one hardener selected from the group consisting of at least one metal oxide, wherein said metal is selected from the group consisting of zinc, aluminum, magnesium, alkaline earth metal oxides and mixtures thereof, said absorbent being capable of absorbing carbon dioxide and other acidic components and said reaction product being formed by heating the above mixture to effect a chemical reaction between the components of the above mixture with formation of a reaction product wherein said liquid absorbent material and said hardener combine upon heating to form said soli

Abstract: A method for the regeneration of an acid gas absorbing fluid which comprises bringing a gaseous mixture containing an acid gas such as, for example, gasified coal gas, synthesis gas, coke oven gas, petroleum gas, natural gas, and the like, into contact with an absorbing fluid containing methyldiethanolamine and a (lower alkyl)piperizine such as, for example, 2-methylpiperazine or 2,5-dimethylpiperazine, so as to absorb the acid gas into the absorbing fluid, and regenerating the absorbing fluid by releasing the acid gas from the absorbing fluid by releasing the acid gas from the absorbing fluid in a regeneration tower having a temperature of not less than 40° C., preferably from 40° C. to 80° C.

Abstract: The present invention is a process to recover a high purity, high pressure hydrogen gas stream from synthesis gas. The synthesis gas is contacted with a membrane that separates the synthesis gas into a hydrogen-enriched permeate and a hydrogen-depleted non-permeate. The permeate is conveyed to a carbon dioxide absorber. The carbon dioxide absorber removes carbon dioxide using a solvent. The carbon dioxide-rich solvent from the absorber is heated and sent to a gas-liquid contactor, where the solvent is regenerated by nitrogen stripping. A small recycle stream of a regenerating gas, i.e., hydrogen, is subsequently contacted with the solvent, stripping entrained and dissolved nitrogen from the solvent. This stripping gas, the regenerating gas, or preferably both, are then mixed with the non-permeate for combustion in a combustion turbine.

Abstract: Disclosed is process for recovering carbon dioxide, comprising (A) providing a gaseous feed stream comprising carbon dioxide, wherein the pressure of said feed stream is up to 30 psia; (B) preferentially absorbing carbon dioxide from said feed stream into a liquid absorbent fluid to form a carbon dioxide enriched liquid absorbent stream; (C) in any sequence or simultaneously, pressurizing said carbon dioxide enriched liquid absorbent stream to a pressure sufficient to enable the stream to reach the top of the stripper at a pressure of 35 psia or greater, and heating the carbon dioxide enriched liquid absorbent stream to obtain a heated carbon dioxide enriched liquid absorbent stream; and (D) stripping carbon dioxide from said carbon dioxide enriched liquid absorbent stream in a stripper operating at a pressure of 35 psia or greater and recovering from said stripper a gaseous carbon dioxide product stream having a pressure of 35 psia or greater.

Abstract: A method for removing residual VOC components from a fluid stream used in the sweetening of sour gas at gas processing plants. In a retrofit configuration, the method includes interposing a supplemental VOC removal station after a primary VOC removal station in an absorbent fluid stream. The absorbent fluid stream incorporates fluid into which sour gas components and VOC have been absorbed from a treated gas stream such as produced natural gas. The primary VOC removal station is configured to remove an initial portion of the absorbed VOC from the absorbent fluid stream. The supplemental VOC removal station is configured to liberate a portion of residual absorbed VOC remaining in the absorbent fluid stream downstream from the primary VOC removal station. Further, the supplemental VOC removal station is configured to avoid liberating absorbed sour gas components from the absorbent fluid stream.

Abstract: An absorbent composition for the removal of acid gases, such as CO2, H2S and COS, from gas streams is provided. The absorbent composition comprises an aqueous solution comprising: 1) greater than 1 mole piperazine per liter of aqueous solution; and 2) about 1.5 to about 6 moles methyldiethanolamine per liter of aqueous solution.

Abstract: The present invention relates to the use of an absorption liquid for purifying a gas by removal of gaseous, acidic impurities. The gas to be purified can be any gas, such as synthesis gas or natural gas, which contains gaseous, acidic impurities such as CO2, H2S, SO2, CS2, HCN, COS or mercaptans. The absorption liquid comprises: A) from 0.01 to 4% by weight of at least one compound of the formula B) from 0.001 to 8.0% by weight of water, and C) at least one polyalkylene glycol alkyl ether of the formula R1—O—(R2—O)x—R3 to 100% by weight, where R1 is C1-C4-alkyl, R2 is ethylene or 2-methylethylene, R3 is hydrogen or C1-C4-alkyl, R4 is hydrogen or C1-C4-alkyl, R5 is C1-C4-alkylene and X is an integer from 1 to 10. The amine may be N-methyldiethanolamine and the ether may be polyethylene glycol dimethyl ether.

Abstract: A process is provided for removing carbon dioxide out of combustion exhaust gas by scrubbing the exhaust gas with an aqueous solution of monoethanolamine in a scrubber, and regenerating the carbon dioxide-loaded aqueous solution of monoethanolamine in a regenerator. The process is provided with means for replenishing the aqueous solution of monoethanolamine with a stock, aqueous solution containing from about 70% to about 75% by weight of monoethanolamine. By providing a stock, aqueous solution containing from about 70% to about 75% by weight of monoethanolamine, which is injected into the carbon dioxide-loaded aqueous solution of monoethanolamine being transferred from the scrubber to the regenerator, the entire carbon dioxide recovery system is free from flammables, rendering fire-fighting precautions unnecessary.

Abstract: Disclosed is a process for the efficient removal of carbon dioxide from a gas recycle system generated in an epoxidation process wherein 1,3-butadiene is selectively oxidized to 3,4-epoxy-1-butene. Carbon dioxide at low partial pressure is absorbed into an alkanolamine solution from a low pressure recycle gas stream containing high levels of oxygen. Also disclosed is a means for reclaiming the alkanolamine from a solution of a carbon dioxide-alkanolamine salt or adduct formed in the carbon dioxide removal process.

Abstract: Alkanolamines of the formula R—NHCH2CH(OH)CH2CH3  (I) or mixtures thereof wherein R is H, —CH2CH(OH)CH2CH3, an alkyl group having from 1 to 6 carbon atoms, an aryl group having from 6 to 12 carbon atoms, an aralkyl group having from 6 to 12 carbon atoms, or a cycloalkyl group having from 3 to 6 carbon atoms in combination with a tertiary alkano/amine are effective in the removal of acidic gases from a fluid stream containing same and show superior degradation properties as compared to alkanolamines conventionally used in the gas purification applications.

Abstract: The invention is a process for separating acid gases from synthesis gas and treating the resulting solids. A mixture comprising synthesis gas and acid gas is contacted with a fluid that reacts with said acid gas to form a particulate solid dispersed in a fluid. The slurry comprising fluid and particulate solid is filtered to separate the particulate solid from the fluid by means of a regenerable filter. The particulate solids are removed from the regenerable filter by back-washing with a back-washing fluid to form a pumpable slurry comprising a mixture of particulate solids and back-washing fluid. The slurry is gasified to form synthesis gas and vitrified solids.

Abstract: Sour natural gas is processed to remove the sulfur compounds and recover C4+/C5+ hydrocarbons by scrubbing the gas with an amine solution to remove most of the sulfur, followed cooling the gas to remove C4+/C5+ hydrocarbons and more sulfur compounds as liquid condensate to produce a gas having less than 20 vppm of total sulfur. The condensate is sent to a fractionator to recover the C4+C5+ hydrocarbons. The sulfur and hydrocarbon reduced gas is contacted first with zinc oxide and then nickel, to produce a gas having less than 10 vppb of total sulfur which is passed into a synthesis gas generating unit to form a very low sulfur synthesis gas comprising a mixture of H2 and CO. This synthesis gas is useful for hydrocarbon synthesis with increased life of the hydrocarbon synthesis catalyst and greater hydrocarbon production from the hydrocarbon synthesis reactor. Contacting the synthesis gas with zinc oxide further reduces the sulfur content to below 3 vppb.

Abstract: A method for recovering carbon dioxide by absorption of carbon dioxide from a gas stream into a composite recovery solvent comprising preferably a lesser concentration of one or more fast reaction rate amines and a greater concentration of one or more slow reaction rate amines.

Abstract: Aqueous compositions comprising a mixture of a tertiary alkanolamine and a primary alkanolamine of the formulaR--CH(NH.sub.2)--CH.sub.2 --OH (I)or mixtures thereof wherein R is H, or an alkyl group having from 1 to 8 are effective in the removal of acidic gases from a fluid stream containing same and show superior degradation properties as well as unexpectedly low degradation, corrosivity and metals solubility properties.

Abstract: A system for recovering absorbate such as carbon dioxide using an alkanolamine absorbent fluid, wherein the loaded absorbent is heated in a two step heating procedure prior to the separation of the absorbate from the absorbent, and wherein the loaded absorbent is deoxygenated after the first heating step and prior to the second heating step.

Abstract: The present invention provides a process for recovering a basic amine compound which comprises the steps of (a) supplying a CO.sub.2 -containing gas to a carbon dioxide absorption unit in which an absorbing solution, which contains a basic amine compound, absorbs carbon dioxide; (b) bringing the gas, from which carbon dioxide has been removed, into vapor-liquid contact with a washing water at a temperature from 20 to 60.degree. C. in an amine recovering unit of a carbon dioxide removal tower, recovering part of the basic amine compound accompanying the gas into the water phase and discharging the gas as an exhaust gas of the carbon dioxide removal tower; and (c) collecting the basic amine compound which remains in the exhaust gas of the carbon dioxide removal tower by passing the exhaust gas pass through a demister at a temperature from 20 to 60.degree. C. The basic amine compound can be recovered efficiently from the gas of the carbon dioxide removal tower by using the above process.

Abstract: There is provided a process for treating a process gas or liquid to remove acid gases which includes treating a relatively lean amine gas scrubbing solution to further reduce the acid gas content of at least a portion of that lean amine gas scrubbing solution such that it becomes an ultra-lean amine solution (one substantially free of acid gas) and the beneficial use of the ultra-lean amine solution to obtain further reductions in the acid gas contents of specific gas or liquid process streams not possible with lean amine solutions having higher residual acid gas loadings. In another aspect of this invention there is provided a process for producing the ultra-lean amine.

Abstract: This invention provides a method for the removal of carbon dioxide present in gases which comprises bringing a CO.sub.2 -containing gas into contact with an aqueous solution containing at least one amine compound of the general formula ##STR1## wherein R.sup.1 to R.sup.8 may be the same or different and each represent a hydrogen atom or an alkyl group of 1 to 4 carbon atoms, and m is 0 or 1. The method of the present invention makes it possible to remove carbon dioxide efficiently. In particular, since carbon dioxide can be easily desorbed by heating the aqueous solution having absorbed carbon dioxide, the thermal energy required for regeneration of the aqueous solution can be reduced.

Abstract: There are disclosed a method for removing CO.sub.2 from a combustion exhaust gas which comprises the step of bringing the combustion exhaust gas under atmospheric pressure into contact with an aqueous solution of a hindered amine selected from the group consisting of 2-amino-2-methyl-1-propanol, 2-methylaminoethanol, 2-ethylaminoethanol and 2-piperidineethanol; and another method for removing carbon dioxide from a combustion exhaust gas which comprises the step of bringing the combustion exhaust gas under atmospheric pressure into contact with a mixed aqueous solution of 100 parts by weight of an amine compound (X) selected from the group consisting of 2-amino-2-methyl-1,3-propanediol, 2-amino-2-methyl-1-propanol, 2-amino-2-ethyl-1,3-propanediol, t-butyldiethanolamine and 2-amino-2-hydroxymethyl-1,3-propanediol; and 1-25 parts by weight of an amine compound (Y) selected from the group consisting of piperazine, piperidine, morpholine, glycine, 2-methylaminoethanol, 2-piperidineethanol and 2-ethylaminoethanol.

Abstract: The present invention generally provides sulfide scavenger solutions and processes that have high sulfide scavenging capacity, provide a reduction or elimination of solids formation and avoid the use of chemicals that pose environmental concerns. The invention utilizes a dialdehyde, preferably ethanedial, for the purpose of reacting with amines, amine carbonates, or other derivatives of amines that are liberated when certain scavenger solutions react with sulfides, including hydrogen sulfide and mercaptans. The scavenger solutions that have been discovered to liberate amines are those formed by a reaction between an amine and an aldehyde.

Abstract: This invention provides a method for the removal of carbon dioxide present in gases which comprises bringing a CO.sub.2 -containing gas into contact with an aqueous solution containing at least one amine compound of the general formula ?1! ##STR1## wherein R.sup.1 to R.sup.8 may be the same or different and each represent a hydrogen atom or an alkyl group of 1 to 4 carbon atoms, and m is 0 or 1. The method of the present invention makes it possible to remove carbon dioxide efficiently. In particular, since carbon dioxide can be easily desorbed by heating the aqueous solution having absorbed carbon dioxide, the thermal energy required for regeneration of the aqueous solution can be reduced.

Abstract: This invention provides a process for effecting desulfurization and decarbonation in two stages. A gas containing sulfur oxides and carbon dioxide is first treated in a desulfurization step so as to cause sulfur oxides to be absorbed in the form of calcium-sulfur oxide compounds; the gas is then treated in a decarbonation step so as to cause carbon dioxide and any sulfur oxides escaping from the desulfurization step to be absorbed in the form of amine salts; the absorbing solution containing the amine salts is regenerated by liberating carbon dioxide therefrom; a part of the regenerated absorbing solution is recycled to the decarbonation step while the remainder of the absorbing solution is fed to a secondary regeneration step where it is treated with a basic calcium substance to regenerate basic amine compound for recycle and to form a solid containing calcium-sulfur oxide compounds and calcium carbonate.

Abstract: This invention relates to a process for removing highly concentrated CO.sub.2 from high-pressure natural gas and recovering it in a high-pressure state.This process comprises the absorption step of bringing high-pressure natural gas having a CO.sub.2 partial pressure of 2 kg/cm.sup.2 or greater and a pressure of 30 kg/cm.sup.2 or greater into gas-liquid contact with a regenerated CO.sub.2 -lean absorbing fluid comprising a CO.sub.2 absorbing fluid of which the difference in saturated CO.sub.2 absorption level between 40.degree. C. and 120.degree. C. is not less than 30 Nm.sup.3 per ton of solvent at a CO.sub.2 partial pressure of 2 kg/cm.sup.2, whereby highly concentrated CO.sub.2 present in the high-pressure natural gas is absorbed into the CO.sub.2 -lean absorbing fluid to produce refined natural gas having a reduced CO.sub.2 content and a CO.sub.2 -rich absorbing fluid; and the regeneration step of heating the CO.sub.2 -rich absorbing fluid without depressurizing it, whereby high-pressure CO.sub.

Abstract: The present invention provides a method for rejuvenating an aqueous alkanolamine solution being at least partially deactivated from contact with an acid gas, said rejuvenation method comprising contacting said aqueous alkanolamine solution with hydrogen in the presence of a hydrotreating catalyst under hydrotreating conversion conditions including contact time sufficient to increase the acid gas sorption capacity of said aqueous alkanolamine solution.

Abstract: A treatment method for removing acid gases by contacting a sour gas stream with a solvent (e.g. an organic amine) which absorbs H.sub.2 S in preference to CO.sub.2 and hydrocarbons. The rich solvent is then regenerated by selectively separating the absorbed hydrocarbons in a first flash, a large portion of the CO.sub.2 in a high-temperature, low-pressure second flash tank, and the substantially all of the remaining acid gases in a high-temperature, low-pressure stripper. The regenerated solvent is recycled and the recovered acid gases are processed to recover sulphur from the H.sub.2 S. The CO.sub.2 recovered from the second tank is contacted with a second solvent to provide high-quality CO.sub.2.

Abstract: This invention relates to methods for the removal of hydrogen sulfide from various gases containing hydrogen sulfide. In order to remove hydrogen sulfide, an aqueous solution containing a di(lower alkyl)amino-(lower alkanol) or triethylenediamine is used. In order to remove hydrogen sulfide selectively from gases containing carbon dioxide and hydrogen sulfide, an aqueous solution containing tert-butyldiethanolamine, triisopropanolamine, triethylenediamine or 2-dimethylamino-2-methyl-1-propanol is used. In order to remove both carbon dioxide and hydrogen sulfide from gases containing carbon dioxide and hydrogen sulfide, an aqueous solution containing a mono(lower alkyl)amino-(lower alkanol) is used.

Abstract: This invention relates to a process for the removal of carbon dioxide from gases which comprises the carbon dioxide absorption step of bringing a gas having a carbon dioxide partial pressure in the range of 0.3 to 50 atmospheres (absolute pressure) into gas-liquid contact with an absorbing fluid comprising an aqueous solution containing an amine compound of the general formula ?1!R.sup.1 R.sup.2 NCH.sub.2 CH(OH)CH.sub.2 OH ?1!where R.sup.1 and R.sup.2 independently represent lower alkyl groups of 1 to 3 carbon atoms, so as to produce a treated gas having a reduced carbon dioxide content and a carbon dioxide-rich absorbing fluid; and the regeneration step of liberating carbon dioxide from the carbon dioxide-rich absorbing fluid by (1) flashing at atmospheric pressure or in the vicinity of atmospheric pressure and/or (2) steam stripping, so that a carbon dioxide-lean absorbing fluid is regenerated and recycled for use in the carbon dioxide absorption step.

Abstract: Absorption solvents for removing mercaptans from gas streams are disclosed. The absorption solvents comprise an alkylether of a polyalkylene glycol, e.g., methoxytriglycol, and a secondary monoalkanolamine, e.g., N-methylethanolamine, as well as optionally other amines, e.g., methyldiethanolamine and diethanolamine. The absorption solvents do not require the presence of iodine for removal of mercaptans. Absorption processes utilizing the solvents are also disclosed.

Abstract: A process for removing H2S and mercaptans from gas streams. The process comprises contacting such gas streams with an aqueous solution of copper complex of a water soluble amine to form water insoluble copper sulfide and regenerate free water soluble amine. The copper sulfide is removed from the system and recovered. Lastly, additional copper complex of the water soluble amine is formed by reacting the regenerated water soluble amine with a copper compound.

Abstract: A system and method for injecting a gaseous contaminant absorbent through at least one spray nozzle into a pipe transporting gas to a contacting vessel wherein the gas is contacted with a liquid absorbent to remove at least one gaseous contaminant from the gas is provided. The injection of the absorbent through the spray nozzles augments the efficiency of the contacting vessel by removal of a quantity of the gaseous contaminant from the gas prior to charging the gas to the contacting vessel. Water vapor is removed using a glycol absorbent and acidic gases are removed using an amine solution as an absorbent. A system and method for the removal of both water vapor and acidic gases is provided.

Abstract: A method is provides for reducing the levels of hydrogen sulfide and organic sulfides present in gaseous hydrocarbon streams by contacting the streams with a composition comprising the reaction product of an alkanolamine with a C1 to C4 dialdehyde, especially ethanedial. The method involves delivery and storage of the reactants near the gas stream to be cleaned, forming the reaction product at a rate substantially equal to the consumption of scavenger by the sulfides, delivering the scavenger to a contacting vessel, contacting the sulfides in the gas stream with the scavenger to reduce the sulfide concentration below a given level, separating the gas stream from the spent scavenger and removing the spent scavenger from the vessel.

Abstract: A process for removing both CO.sub.2 and NO.sub.x from combustion gases consists, first, in cooling a combustion gas to 50 to 100.degree. C. and adding ozone to oxidize NO in the combustion gas to NO.sub.2. Then in a CO.sub.2 removal step, the gas is brought into contact with an aqueous solution of an alcoholic hydroxyl-containing secondary- or tertiary-amine to remove NO.sub.2 together with CO.sub.2 from the gas.

Abstract: A method for inhibiting corrosion of metals in contact with an aqueous alkanolamine solution in an amine unit for removing of acid gases from a hydrocarbon, comprising adding to the solution a sufficient amount of a corrosion-inhibiting composition comprising a blend of salicylic acid with a reaction product of maleated tall oil fatty acid polyhydroxy polyalkane and ammonium or potassium hydroxide; tallow diamine quaternary dichloride or alkanediol or mixtures thereof, and alkanol or alkanolamine. The blend may be diluted in water and may optionally include an antifoam material.

Abstract: This invention relates to the process for removing CO.sub.2 from CO.sub.2 -containing gas such as combustion gas. For example, it is the process for removing CO.sub.2 from combustion gas through the contact of the gas at the atmospheric pressure with an aqueous solution of an amine represented by the general formula R.sup.1 NHC(CH.sub.3).sub.2 CH.sub.2 OH in which R.sup.1 is a lower alkyl group having 1-4 carbon atoms, or an aqueous solution containing both an amine represented by the general formula R.sub.2 CHR.sub.3 NHCH.sub.2 CH.sub.2 OH in which R.sup.2 is a hydrogen atom or a lower alkyl group having 1-4 carbon atoms and R.sup.3 is a hydrogen atom or methyl group and a piperazine compound selected from the group consisting of piperazine, 2-methylpiperazine, 2,3-dimethylpiperazine, and 2,5-dimethylpiperazine, or an mixed aqueous amine solution containing a secondary amine and a tertiary amine at concentrations of 10-45% by weight each, or an aqueous solution of a piperazine derivative.

Abstract: In the process for purifying an aqueous MDEA-solution the formate content of the MDEA-solution circulated in a main stream between the absorber and desorber of a hydrogen sulfide wash unit for gas produced by gasification of a carbonaceous material, e.g. coal, is measured. A partial stream of MDEA-solution is withdrawn from the main stream, passed over an ion exchange medium which removes some formate present to form a partially purified partial stream and subsequently the purified partial stream is returned to the main stream. The amount of the withdrawal from the main stream is controlled so that the formate content of the main stream is maintained between 10 and 30 g/l. Only from 0.5 to 0.08% by volume need be withdrawn from the main stream to form the partial stream. The ion exchange medium can be regenerated with a hydroxide-containing solution, which is subsequently fed to an ammonia separator column of a hydrogen sulfide wash apparatus.

Abstract: Absorption solvents for removing mercaptans from gas streams are disclosed. The absorption solvents comprise an alkylether of a polyalkylene glycol, e.g., methoxytriglycol, and a secondary monoalkanolamine, e.g., N-methylethanolamine, as well as optionally other amines, e.g., methyldiethanolamine and diethanolamine. The absorption solvents do not require the presence of iodine for removal of mercaptans. Absorption processes utilizing the solvents are also disclosed.

Abstract: Improved processes for treating gas streams containing hydrogen sulfide and carbon dioxide, particularly natural gas streams. 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.