Abstract: The natural gas is successively contacted in column CA with a relatively methanol-rich solvent flowing in through line 4, then with a relatively poor solvent flowing in through line 9. The acid gas-containing solvent recovered through line 3 at the bottom of column CA is expanded through valves V1 and V2 to release acid gases through line 6. A fraction of the expanded solvent is distilled in column CR. The regenerated solvent obtained at the bottom of column CR is sent to the top of column CA through line 9. A second fraction of the expanded solvent is mixed with a solvent drawn off from column CR at an intermediate point between the bottom and the top of this column. This mixture of solvents is sent through line 4 into column CA.

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 process and equipment for extracting and disposing of sour reservoir components initially contained in natural hydrocarbons. The stream of natural hydrocarbons extracted from a reservoir is initially subjected to an optional gas/liquid separation. The gaseous hydrocarbons are then scrubbed with a liquid absorbent to dissolve sour reservoir components such as hydrogen sulphide and carbon dioxide and thereby form a solution. The liquid absorbent may be water that is preferably sufficiently free of oxygen and solids to be of a quality suitable for re-injection. The solution is pumped back into a well. The well may be the reservoir that produced the hydrocarbons, or adjacent geological formations, with the re-injected sour water being employed for production stimulation. Alternatively, the well may be a depleted reservoir. The scrubber may be a multiple-stage packed column or tray column that preferably allows for condensate skimming.

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 process for treating a gas containing acid gases, the gas is contacted with a methanol-containing aqueous phase and is then contacted in an absorption column with a mixture of solvents including mehtanol, water and a solvent heavier than methanol. Then, the mixture of solvents is at least partly regenerated through pressure reduction and/or heating. The treated gas is cooled by producing at least a methanol-containing aqueous phase that is at least partly recycled. The mixture of solvents flowing out at the bottom of the absorption column is cooled, then re-introduced at a higher level of the absorption column so as to control the temperature in the absorption column.

Abstract: A process and system for producing fertilizers with reduced levels of contaminants, and particularly a flue gas scrubbing process and facility that produce a fertilizer byproduct which is treated to remove heavy metals originally present in the scrubbed flue gas. The process entails contacting a flue gas with a scrubbing solution to remove acidic gases and produce a byproduct containing a fertilizer compound precipitate and dissolved metals and/or metal compounds. A fertilizer solution containing dissolved fertilizer and dissolved metals and/or metal compounds is then produced by adding water to the byproduct, after which the pH of the fertilizer solution is adjusted one or more times with a gaseous and/or liquid alkali to form precipitates of one or more metal species. The precipitates are then removed from the fertilizer solution and the solution dewatered to yield a fertilizer product with lower contaminant levels.

Abstract: A method for removing CO2 from a CO2-containing hydrocarbon asset. The process includes contacting a CO2-containing hydrocarbon asset with an aqueous liquid stream at an underwater location so that at least a portion of the CO2 in the hydrocarbon asset is dissolved into the aqueous liquid stream, creating a CO2-depleted hydrocarbon asset and a CO2-enriched aqueous stream. The CO2-enriched aqueous stream is separated from the hydrocarbon asset. Finally, the CO2-enriched aqueous stream is disposed of in at least one of a marine environment, a terrestrial formation, or combination thereof.

Abstract: An improved method and structure for purification of an acid gas stream by using raw fuel gas as a stripper to remove the BTEX and VOCs from the liquid amine stream. The improved method is particularly useful for purification of acid gas streams with BTEX contaminant levels in excess of environmentally acceptable levels for standard processing. Raw fuel gas is utilized at moderate temperatures and pressures, the uptake of BTEX and VOCs reduces the level of these compounds in the waste amine stream to environmentally acceptable levels, and the remaining contaminants may then be dealt with by ordinary means. Levels of H2S and CO2. in the liquid amine stream are also 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: The present invention relates to a method for separation of gas constituents from a multicomponent gaseous mixture employing a hydrate promoter. The method for separation of gas constituents from a multicomponent gaseous mixture includes the steps of reacting an aqueous solution containing a hydrate promoter with a multicomponent gaseous mixture to form a gas hydrate condensed with the gas constituents of high gas hydrate forming power and dissociating a specific gas component from the gas hydrate. In accordance with the present invention, a specific gas component can be seperated from a multicomponent gaseous mixture under a pressure much lower than that of the prior art method, which makes possible its practical application in various industrial areas emitting exhaust gases.

Abstract: An exhaust heat utilization method for a carbon dioxide recovery process comprises heating returning hot water by at least one heat exchange selected from heat exchange with the regenerated absorbing liquid after heat exchange, heat exchange with carbon dioxide exhausted from the regeneration tower, and heat exchange with saturated water after heating the bottom of the regeneration tower, thereby obtaining hot water.

Abstract: In a wet-process gas treatment method of treating an acid gas by means of at least two treating columns connected in series, ratio of concentration of acid gas at an outlet to concentration of acid gas at an inlet, of a first treating column is set higher than ratio of concentration of acid gas at an outlet to concentration of acid gas at an inlet, of at least one of other treating columns, thereby preventing deposits from forming in the interior of connecting pipes between the columns and in the interiors of the treating columns, to prevent the connecting pipes from their blockage.

Abstract: In a method of separating carbon dioxide from a gas mixture, a liquid solvent flows down an array of vertical wires with the gas mixture flowing over the liquid. Once on the wire, the liquid quickly breaks up into drops of varying sizes, with each size moving down the wire at a different velocity. Large, faster moving drops overtake the small, slower moving drops to form even larger drops. As the drops fall, new drops are created behind the falling drops. Consequently, drops of a large range of sizes are forming, colliding, and mixing as they travel down the wire. During this process, gas molecules that have adsorbed onto the liquid surface are mixed into the interior of the solvent, resulting in highly effective mass transfer and gas absorption. This enhanced mass transfer allows greater flexibility in the choice of solvent and in the system design.

Abstract: The present invention provides a method for purifying a gas by contacting the gas with a liquid ionic compound. Natural gas may be purified, removing water and carbon dioxide, by contacting the natural gas with a liquid ionic compound.

Abstract: The present invention relates to a device for treatment of an exhaust gas or a flue gas stream. The device comprises one or more entities (3) embracing frictional elements (10, 20, 110, 230, 310, 330, 400) attached to, and which are able to rotate with, a hollow axle (4) and one or more pipes (5) running axially inside the hollow axle for transporting of necessary auxiliary fluids to effect the gas treatment. Furthermore, the invention relates to a method for treatment of an exhaust gas or a flue gas stream flowing through an exhaust gas duct or flue gas duct. The method comprises that the gas stream is conducted through one or more entities embracing functional elements attached to, and rotating with, a hollow, rotating axle and where necessary auxiliary fluids effecting the gas treatment enter and leave the functional element in each entity through pipes running axially inside the axle. The invention is particularly applicable for energy recovery and/or removal of CO2 from exhaust or flue gas.

Abstract: A gas separation apparatus and process has a first pressure swing adsorption (PSA) unit (110) receiving feed gas (112), which comprises a first and a second component. First PSA unit (110) produces first product gas (114) pre-dominantly containing the first component, and first off gas (116) containing at least some of the first component and second component. Compressor (120) is coupled to first PSA unit (110) to compress first off gas (116) to form compressed off gas (126), which is passed downstream to absorber unit (130), which employs a solvent to remove at least part of the second component from compressed off gas (126), forming an enriched compressed off gas (136B). Second PSA unit (140) receives enriched compressed off gas (136B) and produces second product gas (142) which predominantly contains the first component and a second off gas that is sent to waste or reformer burner (150).

Abstract: A process for adsorbing hydrocarbons from an acid gas stream includes passing the acid gas stream through an adsorbent which selectively removes hydrocarbons, desorbing the hydrocarbons from the adsorbent and contacting the desorbed hydrocarbons with an acid gas removal solution to remove acid gases which have been coadsorbed with the hydrocarbons. The process is particularly useful in removing hydrocarbons from a hydrogen sulfide-containing stream which is being directed to Claus processing for conversion into elemental sulfur. Useful adsorbents include crystalline titanium silicate molecular sieves containing titania octahedral sites such as ETS-10 and similar materials, as well as high silica aluminosilicate zeolite.

Abstract: In a process intended for dehydration/fractionation of a wet natural gas containing <<heavy>> constituents and <<light>> constituents, in the presence of methanol, which comprises at least the following stages

Abstract: The loaded wash liquid contains H 2 S, CO, H 2 , CO 2 , nickel carbonyl and/or iron carbonyl. Carbon monoxide is initially and partially removed from the loaded wash liquid and the wash liquid which is low in CO is conducted through a reaction and settling zone. Sludge containing nickel and/or iron sulfide is extracted from the reaction and settling zone and the wash liquid is conducted to a heat regeneration device The regenerated wash liquid can be re-utilized for desulfurization purposes.

Abstract: Process for the removal of metal cabonyls before regeneration of a desulfurization wash liquid, which includes removing a part of the carbon monoxide from the wash liquid, conversion of the metal carbonyls to metal sulfides, passing the wash liquid through a reaction and settling zone, removing metal sulfide-containing sludge from the reaction and settling zone, and regenerating the wash liquid.

Abstract: A new method called phase enhanced gas-liquid absorption has been developed. By addition of organic phase into the absorption system of gas aqueous phase, the absorption rate was increased significantly. Absorption rate was enhanced by organic phase.

Abstract: A method which reduces iron contamination of a system which receives ammonia from an ammonia recovery process by one or more of the following techniques:

Abstract: A process for removing acidic gas constituents, of the group consisting of CO2, H2S, COS, CS2 and mercaptans, from gases, in which, in an absorption step, a dirty gas rich in acidic gas constituents is brought into contact with an absorption medium, as a result of which a clean gas low in acidic gas constituents and an absorption medium laden with acidic gas constituents are obtained, the absorption medium used being a mixture comprising a) from 0.1 to 50% by weight of one or more mono-cyclic or bicyclic nitrogen heterocycles which are unsubstituted and/or monosubstituted or poly-substituted on the carbon by OH, C1-C3 alkyl and/or C1-C3 hydroxyalkyl and which have from 5 to 14 ring atoms and 1 or 2 heterocyclically bound nitrogen atoms per ring as component A, b) from 1 to 60% by weight of a monohydric and/or polyhydric alcohol as component B, c) from 0 to 60% by weight of an aliphatic aminoalcohol as component C, d) from 0 to 98.

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: 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: A process is provided for reducing a greenhouse gas emission component of a combustion gas from a thermal power generation plant. The thermal power generation plant is located in a coastal region adjacent the ocean. The plant is located beneath a seawater reservoir and a discharge line via a cooling water loop provides cooling water to the power station. The discharge line in turn feeds a modified hydroelectric plant and an intake pipe is located with its outlet beneath the ocean surface. A bypass line is connected to the discharge line 14 and extends to deep ocean sinks. In operation, seawater is pumped from the ocean to the elevated reservoir via the intake pipe and discharge line and thereafter combustion gas from the flue stack or emission system of the power station is injected into the discharge line. Electricity is generated by the power station during peak demand periods.

Abstract: Process for pretreating a very acid natural gas containing a substantial amount of hydrogen sulfide (H2S), possibly combined with carbon dioxide (CO2), comprising at least a stage wherein the initial natural gas is contacted in a distillation column with a liquid condensate itself resulting from cooling of the gaseous fraction obtained during said contacting stage. This solution allows to eventually recover at a lower cost a gas enriched in methane, depleted in hydrogen sulfide and freed from substantially all of the water it contains, and a liquid phase containing most of the hydrogen sulfide, substantially all of the water and depleted in hydrocarbon. Control of the thermodynamic conditions during the stages that characterize the process, according to the water content of the gas during treatment, allows progressive exhaustion of the water contained in said gas while preventing hydrates formation.

Abstract: Process for treating a gas containing acid gases, wherein:

Abstract: A process for adsorbing hydrocarbons from an acid gas stream includes passing the acid gas stream through an adsorbent which selectively removes hydrocarbons, desorbing the hydrocarbons from the adsorbent and contacting the desorbed hydrocarbons with an acid gas removal solution to remove acid gases which have been coadsorbed with the hydrocarbons. The process is particularly useful in removing hydrocarbons from a hydrogen sulfide-containing stream which is being directed to Claus processing for conversion into elemental sulfur. Useful adsorbents include crystalline titanium silicate molecular sieves containing titania octahedral sites such as ETS-10 and similar materials, as well as high silica aluminosilicate zeolite.

Abstract: The invention relates to an apparatus for performing membrane gas/liquid absorption at elevated pressure, comprising a pressure vessel in which a membrane unit is provided for separate feed-through of the gas phase and the liquid phase, in such a way that exchange of components to be absorbed can take place between the gas phase and the liquid phase, the flow direction of the gas phase through the absorber being essentially perpendicular to the flow direction of the liquid phase through the absorber. The invention further relates to a method for performing gas/liquid membrane absorption employing this absorber, in particular for the absorption of CO2, H2S, mercury (vapor) and/or water (vapor) from a gas phase at elevated pressure. The invention finally relates to a method for refining natural gas using the absorber and method according to the invention.

Abstract: Methods are provided for the selective removal of CO2 from a multicomponent gaseous stream to provide a CO2 depleted gaseous stream having at least a reduction, e.g. 30 to 90%, in the concentration of CO2 relative to the untreated multicomponent gaseous stream. In practicing the subject methods, the multicomponent gaseous stream is contacted with an aqueous fluid, e.g. CO2 nucleated water, under conditions of selective CO2 clathrate formation to produce a CO2 clathrate slurry and CO2 depleted gaseous stream. A feature of the subject invention is that a CO2 hydrate promoter is employed, where the CO2 hydrate promoter is included in the multicomponent gaseous stream and/or the aqueous fluid. The CO2 hydrate promoter serves to reduce the minimum CO2 partial pressure required for hydrate formation as compared to a control. The subject methods find use in a variety of applications where it is desired to selectively remove CO2 from a multicomponent gaseous stream.

Abstract: A system and method are provided for supplying breathable gas to an underwater habitat submerged in water. A flow of respired gas that includes metabolically-produced carbon dioxide is extracted from the underwater habitat and mixed with water from the surrounding environment. As a result of such mixing, carbon dioxide in the respired gas is substantially absorbed by the water while a first gas is produced. Moisture in the first gas is filtered out to produce a breathable gas which is then introduced back into the underwater habitat.

Abstract: A process for the removal of carbon dioxide, sulphur compounds, water and aromatic and higher aliphatic hydrocarbons from industrial gases. The sour gas components, water and hydrocarbons are removed from the gas to be treated by absorption at elevated operating pressure. At least one morpholine derivative is used as the absorbent. The absorbent laden with absorbed components is regenerated with the aid of a stripping gas. The stripping gas is generated by partial evaporation of the laden absorbent.

Abstract: A process is provided for removing CO2 and/or H2S from a gas mixture containing as impurities CO2 and/or H2S and at least one other impurity selected from the group consisting of a cyanide and ammonia. The process includes contacting at least a portion of the reflux stream from the overhead vapor from a stripping column of an acid gas removal solvent (i.e., alkanolamine) treatment plant with an anion exchange resin to remove corrosive impurities. The ion-exchanged reflux stream is then recycled to the top of the stripping column or into the bulk circulating acid gas removal solvent (i.e., alkanolamine) passing from the bottom of the stripping column.

Abstract: Anaerobic digestion system and process in which the raw digester gas containing methane and other gaseous components is cooled at atmospheric pressure in the presence of a liquid to a temperature at which the other gaseous components have a substantially higher solubility in the liquid than methane and are substantially all absorbed into the liquid, leaving pure, dry methane gas. That methane gas is then used in other parts of the system, including the digester and a refrigeration system for cooling the raw gas.

Abstract: A regenerative process for deacidification of a gas containing CO2 and liquid hydrocarbons including contacting the gas to be treated, in an absorption zone, with an absorbent liquid including methyldiethanolamine (MDEA) and an accelerator of absorption of CO2 by the amine, thereby producing a treated gas with reduced CO2 content and an absorbent liquid loaded with CO2, subjecting the loaded absorbent liquid to a regeneration treatment to release CO2 which it has bound, to produce 1) at least one acid gas fraction rich in CO2 and 2) at least one regenerated absorbent liquid; and recycling into the absorption zone the at least one regenerated absorbent liquid, wherein the overall liquid hydrocarbon content in the gas to be deacidified containing CO2 is greater than 14 liters of liquid hydrocarbons per million standard cubic meters of gas, and the activator combined with methyldiethanolamine in the absorbent liquid brought into contact with the gas containing CO2 and liquid hydrocarbons consists of at least one

Abstract: A method for removing acid gas components from combustion gas and natural gas. The method includes bringing the gas mixture into contact with sea water and subjecting the gas mixture and sea water to turbulent mixing conditions. This causes the acid gas to be absorbed by the sea water. The sea water can be disposed of offshore without any detrimental effect on the environment.

Abstract: The use of a turbulent contactor to absorb a selected gas component from a gas stream. The invention particularly applies to a method of removing selected gas components from a gas stream which includes: bringing the gas stream into contact with a liquid including a solvent or a reagent for the selected gas component in a turbulent contactor, the contactor including a gas inlet, a liquid inlet, an outlet leading to a venturi passage and a tube extending from the outlet back upstream, the tube being perforated and/or being spaced from the periphery of the outlet; subjecting the gas stream and liquid to turbulent conditions in the contactor thereby causing the gas component to be absorbed by the solvent or reagent.

Abstract: A method for removing acid gas components from combustion gas and natural gas. The method includes bringing the gas mixture into contact with sea water and subjecting the gas mixture and sea water to turbulent mixing conditions. This causes the acid gas to be absorbed by the sea water. The sea water can be disposed of offshore without any detrimental effect on the environment.

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: A process for the reclamation of spent aqueous alkanolamine solutions by contacting a spent aqueous alkanolamine solution with a strong base ion exchange resin for time sufficient to sorb from the aqueous alkanolamine solution at least a portion of the accumulated ions and after a high concentration of ions accumulate on the resin, regenerating the strong base ion exchange resin by: a) purging the resin with water or nitrogen, b) contacting the strong base ion exchange resin with a sodium chloride solution for a time sufficient to remove the ions, c) purging the resin to remove the sodium chloride solution, d) contacting the resin with an alkali metal hydroxide solution, preferably sodium hydroxide, for a time sufficient to convert the resin to a substantially hydroxide form; and e) purging the resin, wherein the ion sorption capacity of the resin is maintained at a substantially constant value.

Abstract: Method for purifying gas loaded with dust particles of various sizes, which method comprises the following steps:

Abstract: A system for cleaning a carbon dioxide gas stream of water soluble contaminants with improved recovery of carbon dioxide wherein the water soluble contaminants are removed into countercurrently flowing water which undergoes at least one pressure reduction step releasing absorbed carbon dioxide for recapture and recycle into the carbon dioxide gas stream.

Abstract: The present invention provides a process for removing gas contaminants such as hydrogen sulfide and carbon dioxide from a product gas such as natural gas or synthesis gas. According to the invention the product gas is contacted with a solvent which includes dialkyl ethers of polyethylene glycols and water, and a high pressure recycle loop is utilized to desorb a portion the gas contaminants and co-absorbed product gas from the solvent. The solvent is provided with an amount of water sufficient to increase recovery of co-absorbed product gas while at the same time providing a reduced circulation rate requirement for the solvent and reduced re-compression and cooling requirements for the recycle gas.

Abstract: A method is provided for the extraction of aromatic hydrocarbons, including benzene, toluene, ethylbenzene, and xylene, collectively known as “BTEX,” in a continuous process utilizing a glycol contactor to cause absorption of the BTEX upstream of an amine-based gas sweetening process. The preferred glycol for BTEX absorption is triethylene glycol. The glycol used in the glycol contactor for BTEX extraction may either be fully regenerated (dry), or wet glycol from a downstream gas dehydration system. The method may be achieved with the use of a number of separate absorber/contactor vessels, or the method may be achieved within one combination vessel.

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: A system for regenerating chemical solvent loaded with acid gas with improved energy efficiency wherein the chemical solvent is partially flash vaporized, heated, and passed in countercurrent mass transfer contact with nitrogen gas.

Abstract: A method for determining the efficiency of a carbon filter used to absorb hydrocarbons from organic solvents. A sample of the solution, used to remove CO.sub.2 and H.sub.2 S from natural hydrocarbon gases, is taken after it has passed through the carbon filter. A solution of an internal standard and carbon disulfide is added to the sample to concentrate the hydrocarbons into the solution. A second sample taken from the solution containing the concentrated hydrocarbons and is passed through a gas chromatograph which has a fast temperature ramp to measure the peak areas of the hydrocarbons and the internal standard. The concentration of the measured hydrocarbons are determined by comparing the peak area counts against that of the internal standard.

Abstract: A double-loop process for the removal of specified gas or gases from a process gas by absorption with a liquid absorbent for said specified gas or gases wherein the process gas is contacted counter-currently in a first absorption stage with semi-lean absorbent liquid and then in a second absorption stage with lean absorbent liquid to give a sweet process gas and the absorbed gases are stripped from the laden absorbent liquid in a first stage giving a semi-lean absorbent liquid. Part of the semi-lean absorbent is recycled to the first absorption stage while the remainder is subjected to further stripping by counter-current contact with an auxiliary gas that has a concentration of the specified gas or gases that is lower than the concentration of the specified gas or gases in the process gas to give the lean absorbent liquid which is recycled to the second absorption stage.

Abstract: Methods are provided for the selective removal of CO.sub.2 from a multicomponent gaseous stream to provide a CO.sub.2 depleted gaseous stream having at least a reduction in the concentration of CO.sub.2 relative to the untreated multicomponent gaseous stream. In the subject methods, the multicomponent gaseous stream is contacted with CO.sub.2 nucleated water under conditions of selective CO.sub.2 clathrate formation, where the CO.sub.2 nucleated water serves as a liquid absorbent or adsorbent to produce a CO.sub.2 clathrate slurry and CO.sub.2 depleted gaseous stream. In a preferred embodiment, the CO.sub.2 clathrate slurry is then decomposed to produce CO.sub.2 gas and nucleated water. The subject methods find use in a variety of applications where it is desired to selectively remove CO.sub.2 from a multicomponent gaseous stream, including chemical feedstock processing applications and air emissions control applications.