Abstract: Membranes, methods of making the membranes, and methods of using the membranes are described herein. The membranes can comprise a gas permeable support layer, an inorganic layer disposed on the support, the inorganic layer comprising a plurality of discreet nanoparticles having an average particle size of less than 1 micron, and a selective polymer layer disposed on the inorganic layer, the selective polymer layer comprising a selective polymer having a CO2:N2 selectivity of at least 10 at 57° C. In some embodiments, the membrane can be selectively permeable to an acidic gas. The membranes can be used, for example, to separate gaseous mixtures, such as flue gas.

Abstract: Disclosed are processes for purifying feed streams containing hydrogen sulfide and sulfur-containing impurities by removing sulfur-containing impurities, such as elemental sulfur and polysulfanes, using solid catalytic sorbents. Also disclosed are processes for producing hydrogen sulfide.

Abstract: A method for predicting selective performance of an adsorbent is disclosed. The adsorbent is selected from a list of metals and/or metal cations for use in removing contaminants as thiophene derivatives in hydrocarbon feed. The metals or metal cations are identified from a list having a positive value for Erel, wherein the metal or metal cation having the largest value for Erel is the most selective adsorbent.

Abstract: A method for production of a methionine salt in a reactive rectification column containing a weir having a height of 100 mm or more is provided.

Abstract: A system and method for acid-gas capture wherein organic acid-gas capture materials form hetero-atom analogs of alkyl-carbonate when contacted with an acid gas. These organic-acid gas capture materials include combinations of a weak acid and a base, or zwitterionic liquids. This invention allows for reversible acid-gas binding to these organic binding materials thus allowing for the capture and release of one or more acid gases. These acid-gas binding organic compounds can be regenerated to release the captured acid gasses and enable these organic acid-gas binding materials to be reused. This enables transport of the liquid capture compounds and the release of the acid gases from the organic liquid with significant energy savings compared to current aqueous systems.

Abstract: Provided is a process for controlling heavy metal (e.g., mercury) emission in S02-containing flue gas, comprising passing a stream of the flue gas (2) through a wet scrubber (1) where it is brought into contact with a liquid absorbent (8) comprising an ionic liquid, an oxidizer (11) and polar protic organic solvent, wherein the amount of said organic solvent is adjusted such that the SO2 absorption is minimized while operating said wet scrubber at a temperature lower than the normal working temperature that would be used in the absence of said solvent. The process may be preceded by an initial stage where a fluoride-containing liquid is used for reducing the amount of sulfur dioxide in the flue gas stream; the sulfur dioxide can be subsequently desorbed from the fluoride-containing liquid upon the addition of a polar solvent.

Abstract: A method of removing gaseous organic sulfide contaminants from gaseous mixtures is provided where the method includes dissolving the organic sulfide contaminants in a solution of an acid-based catalyst to permit cleavage of the sulfur atom from the organic sulfide molecule, such that the cleaved sulfur atom can be further reduced electrochemically to elemental sulfur or alkali metal polysulfides.

Abstract: The present invention provides a process for removing mercaptans from a gas stream gas stream, comprising the steps: a) providing a first mercaptan-comprising gas stream comprising at least a mercaptan of the general formula: R1—SH, wherein R1 is an alkyl group comprising 1 to 4 carbon atoms; and b) contacting the mercaptan-comprising gas stream with an absorption medium comprising a substituted disulphide and a nitrogen-containing base to obtain a second mercaptan-depleted gas stream, wherein: the substituted disulphide is of the general formula R2—SS—R3 wherein: R2 and R3 are carbon comprising substituents of which the corresponding R2—SH and R3—SH thiols have a vapor pressure below the vapor pressure of any R1—SH thiol.

Abstract: Disclosed is an sorbent for removing sulfur dioxide (SO2) contained in combustion flue gases or in the atmosphere by using a diamine-based ionic liquid or a diamine compound supported by a polymer resin. To be specific, the present invention relates to a method of using a tertiary diamine compound immobilized on a polymer surface as a SO2 sorbent and also relates to a novel sorbent for absorbing or adsorbing a sulfur dioxide hydrate (SO2.H2O) formed by a bond between SO2 and water.

Abstract: The present invention provides a process for removing mercaptans from a gas stream. In the process, a first mercaptan-comprising gas stream comprising at least a mercaptan of the general formula: R1—SH, wherein R1 is an alkyl group comprising 1 to 4 carbon atoms, and an acid component is contacted with an absorption medium to obtain a mercaptan-depleted gas stream. The absorption medium includes a substituted disulphide and a base. The substituted disulphide is of the general formula R2—SS—R3, wherein R2 and R3 are carbon comprising substituents of which the corresponding R2—SH and R3—SH thiols have a vapor pressure below the vapor pressure of any R1—SH thiol, and at least one of R2 and R3 is an electron withdrawing group.

Abstract: The present invention provides a process for removing mercaptans from a gas stream gas stream, comprising the steps: a) providing a first mercaptan-comprising gas stream comprising at least a mercaptan of the general formula: R1—SH, wherein R1 is an alkyl group comprising 1 to 4 carbon atoms; and b) contacting the mercaptan-comprising gas stream with an absorption medium comprising a substituted disulphide and a nitrogen-containing base to obtain a second mercaptan-depleted gas stream, wherein: the substituted disulphide is of the general formula R2—SS—R3 wherein: R2 and R3 are carbon comprising substituents of which the corresponding R2—SH and R3—SH thiols have a vapour pressure below the vapour pressure of any R1—SH thiol.

Abstract: An adsorbent material comprising a porous inorganic oxide material grafted with a molecule comprising a carbonyl functional group is provided. The porous inorganic oxide material can be a porous silica material or Zr(OH)4. The adsorbent material can be a synthesized by grafting an organosilane molecule containing the carbonyl functional group onto the porous inorganic oxide material. The porous inorganic oxide material can be grafted with a second molecule comprising an amine functional group. Methods of making the adsorbent material and methods of removing molecules from a fluid using the adsorbent material are also provided.

Abstract: This invention provides novel compositions comprising substituted polyamines as acid gas scrubbing solutions and methods of using the compositions in an industrial system. The invention relates to the use of such polyamine compounds in industrial processes to remove acidic contaminants from natural and industrial fluid streams, such as natural gas, combustion gas, natural gas, synthesis gas, biogas, and other industrial fluid streams. The compositions and methods of the invention are useful for removal, absorption, or sequestration of acidic contaminants and sulfide contaminants including CO2, H2S, RSH, CS2, COS, and SO.

Abstract: This invention provides novel compositions comprising substituted polyamines as acid gas scrubbing solutions and methods of using the compositions in an industrial system. The invention relates to the use of such polyamine compounds in industrial processes to remove acidic contaminants from natural and industrial fluid streams, such as natural gas, combustion gas, natural gas, synthesis gas, biogas, and other industrial fluid streams. The compositions and methods of the invention are useful for removal, absorption, or sequestration of acidic contaminants and sulfide contaminants including CO2, H2S, RSH, CS2, COS, and SO.

Abstract: A process for removal of H2S and CO2 from an acid gas stream comprising H2S and CO2, the process comprising the steps of: (a) reacting H2S in the acid gas stream with SO2 to form sulphur vapor and water vapor, thereby obtaining a first off-gas stream comprising CO2, water vapor, sulphur vapor, residual SO2 and residual H2S; (b) converting residual SO2 in the first off-gas stream to H2S in a first off-gas treating reactor, thereby obtaining a second off-gas stream depleted in SO2 and enriched in H2S and CO2 compared to the first off-gas stream; (c) contacting the second off-gas stream with an H2S absorbing liquid, thereby transferring H2S from the gas stream to the H2S absorbing liquid to obtain H2S absorbing liquid enriched in H2S and a third off-gas stream enriched in CO2; (d) removing CO2 from the third off-gas stream by contacting the third off-gas stream with CO2 absorbing liquid in a CO2 absorber, thereby transferring CO2 from the third off-gas stream to the CO2 absorbing liquid to obtain CO2 absorbing l

Abstract: The present invention provides a method of treating an off-gas stream (80) comprising NH3 and H2S to provide a sulphate stream (910), the method comprising the steps of: (i) providing a first off-gas stream (80) comprising NH3, H2S, CO2 and optionally one or more of HCN, COS and CS2; (ii) passing the first off-gas stream (80) to an incinerator (300) to oxidize NH3, H2S, and optionally one or more of HCN, COS and CS2 to provide a second off-gas stream (310) comprising N2, H2O, SO2 and CO2; (iii) scrubbing the second off-gas stream (310) with a first aqueous alkaline stream (380, 876a) in a caustic scrubber (350) to separate SO2 and a part of the CO2 from the second off-gas stream to provide a spent caustic stream (360) comprising carbonate and one or both of sulphite and bisulphite and a caustic scrubber off-gas stream (370) comprising N2 and CO2; and (iv) passing the spent caustic stream (360) to an aerator (900) comprising sulphur-oxidizing bacteria in the presence of oxygen to biologically oxidize sulphite

Abstract: Systems containing imidazoles or blends of imidazoles and amines are described herein. Methods of their preparation and use are also described herein. The methods of using the systems include the reduction of volatile compounds from gas streams and liquid streams.

Abstract: Dry processes, apparatus, compositions and systems are provided for reducing emissions of sulfur oxides, and sulfur dioxide in particular, and/or HCl in a process employing a combination of a dolomite hydrate sorbent and a sorbent doping agent administered to achieve coverage of a three-dimensional cross section of a passage carrying SOx and/or HCl-containing gases with a short but effective residence time at a temperature effective to provide significant sulfur dioxide and/or HCl reductions with high rates of reaction and sorbent utilization. The once-through, dry process can advantageously introduce the sorbent and sorbent doping agent dry or preferably as a slurry to enable uniform treatment. Preferred sorbent doping agents include water-soluble or water-dispersible copper and/or iron compositions which can be heated to an active form in situ by the flue gases being treated.

Abstract: The present invention provides a process for removing mercaptans from a gas stream. In the process, a first mercaptan-comprising gas stream comprising at least a mercaptan of the general formula: R1—SH, wherein R1 is an alkyl group comprising 1 to 4 carbon atoms, and an acid component is contacted with an absorption medium to obtain a mercaptan-depleted gas stream. The absorption medium includes a substituted disulphide and a base. The substituted disulphide is of the general formula R2—SS—R3, wherein R2 and R3 are carbon comprising substituents of which the corresponding R2—SH and R3—SH thiols have a vapour pressure below the vapour pressure of any R1—SH thiol, and at least one of R2 and R3 is an electron withdrawing group.

Abstract: One aspect of the present invention relates to salts that are room-temperature ionic liquids (RTILs), methods of making them, and methods of using them in connection with temporary or permanent gas sequestration. Another aspect of the present invention relates to a class of solvents which can be transformed into RTILs by exposure to a gas, and methods of using them in connection with temporary or permanent gas sequestration.

Abstract: A composite structure for capturing a gaseous electrophilic species, the composite structure comprising mesoporous refractory sorbent particles on which an ionic liquid is covalently attached, wherein said ionic liquid includes an accessible functional group that is capable of binding to said gaseous electrophilic species. In particular embodiments, the mesoporous sorbent particles are contained within refractory hollow fibers. Also described is a method for capturing a gaseous electrophilic species by use of the above-described composite structure, wherein the gaseous electrophilic species is contacted with the composite structure.

Abstract: Disclosed herein is an agglomeration-resistant desulfurizing product for removing contaminants from a fluid stream. The agglomeration-resistant desulfurizing product comprising a metal oxide composition for reacting with contaminants and a polymeric crystallization inhibitor for reducing the agglomeration of the desulfurizing product resulting from using the desulfurizing product. A method to produce the agglomeration-resistant desulfurizing product and a method to treat a fluid stream is also disclosed.

Abstract: This invention provides novel processes utilizing compositions comprising substituted polyamines as acid gas scrubbing solutions and methods of using the compositions in an industrial system. The invention relates to the use of such polyamine compounds in industrial processes to remove acidic contaminants from natural and industrial fluid streams, such as natural gas, combustion gas, natural gas, synthesis gas, biogas, and other industrial fluid streams. The compositions and methods of the invention are useful for removal, absorption, or sequestration of acidic contaminants and sulfide contaminants including CO2, H2S, RSH, CS2, COS, and SO2.

Abstract: A carbon-based catalyst for flue gas desulfurization is brought into contact with a flue gas containing at least SO2 gas, oxygen and water vapor so that the SO2 gas can react with the oxygen and the water vapor to form sulfuric acid which is to be recovered. On a surface of the carbon-based catalyst, iodine, bromine or a compound thereof is added, ion exchanged or supported and a water-repellent treatment is applied. The carbon-based catalyst can also be used as a mercury adsorbent for flue gas treatment for adsorbing and removing metallic mercury from a flue gas containing metallic mercury, SO2 gas, oxygen and water vapor.

Abstract: Systems containing imidazoles or blends of imidazoles and amines are described herein. Methods of their preparation and use are also described herein. The methods of using the systems include the reduction of volatile compounds from gas streams and liquid streams.

Abstract: Certain exemplary embodiments provide methods for reducing a concentration of a contaminant associated with a medium, which can be any substance or material, such as soil, water, air, and/or fluid. In one exemplary method, the medium is treated with a ferric chelate and an oxidizing agent in amounts effective to oxidize at least a portion of the contaminant.

Abstract: Apparatus and methods for recovering sulfur from acid gases. Acid gases containing relatively high amounts of carbonyl sulfide and/or one or more types of mercaptans can be treated in a sulfur recovery system employing an acid gas enrichment zone and a tail gas treatment zone, where partially-loaded sulfur absorbing solvent from the tail gas treatment zone is employed for sulfur absorption in the acid gas enrichment zone. Off-gas from the acid gas enrichment zone can be combined and hydrogenated with a sulfur recovery unit tail gas thereby increasing the total amount of sulfur recovery from the initial acid gas.

Abstract: An ionic liquid composition having the following chemical structural formula: wherein R1, R2, R3, and R4 are independently selected from hydrocarbon groups containing at least 1 and up to 20 carbon atoms, and X? is a cyclic anion that possesses a negatively-charged group reactive with a gaseous electrophilic species, particularly carbon dioxide or sulfur dioxide. Methods for capturing a gaseous electrophilic species, such as CO2 or SO2, by contacting the gaseous electrophilic species with an ionic liquid according to Formula (1) are also described.

Abstract: An absorbent for separating acidic gases is disclosed. The absorbent or an absorbent composition for separating acidic gases has more than 3 kinds of compounds along with Chemical Formula 1 and 2, and has ability of rapid carbon dioxide elimination, excellent absorption ability, and less energy consumption for regenerating an absorbent due to easy desorption of carbon dioxide.

Abstract: Absorption medium for acid gases comprising an oligoamine (A) of the general formula (I) and a piperazine derivative (B) of the general formula (II) in which the weight ratio of oligoamine (A) to the piperazine derivative (B) is 0.2 to 25, and also process for removing acid gases from a gas stream by contacting the gas stream at a pressure of 0.05 to 10 MPa abs with an aqueous solution of said absorption medium which is brought to and maintained at a temperature of 20 to 80° C.

Abstract: The use of a dialdehyde (e.g. glyoxal) and a nitrogen-containing scavenger (e.g. a triazine) when injected separately in media containing hydrogen sulfide (H2S) and/or mercaptans to scavenge H2S and/or mercaptans therefrom gives a synergistically better reaction rate and overall scavenging efficiency, i.e. capacity, over the use of the dialdehyde or the nitrogen-containing scavenger used alone, but in the same total amount of the dialdehyde and nitrogen-containing scavenger. The media may include an aqueous phase, a gas phase, a hydrocarbon phase and mixtures of a gas and/or hydrocarbon phase with an aqueous phase.

Abstract: Compositions and methods relating to aromatic imine compounds and methods of their use are described. The compounds are formed from aromatic aldehydes and amino or amino derivatives. The compounds and their derivatives are useful, for example, as hydrogen sulfide and mercaptan scavengers for use in both water and petroleum products.

Abstract: An improved process for deacidizing a gaseous mixture using phase enhanced gas-liquid absorption is described. The process utilizes a multiphasic absorbent that absorbs an acid gas at increased rate and leads to reduced overall energy costs for the deacidizing operation.

Abstract: A composition for removing mercaptan from a gas stream containing at least one acid gas in addition to a mercaptan, the composition comprising a physical and/or chemical solvent for H2S and an inclusion compound for the mercaptan. A process of treating gas stream using the composition. The inclusion compound is selected from the group consisting of, cyclodextrin, cryptand, calixarene, cucurbituril. The chemical solvent may be monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA, diisopropylamine (DIPA), diglycolamine (DGA) and methyldiethanolamine (MDEA). Examples of useful physical solvents include cyclotetramethylene sulfone (sulfolane) and its derivatives, aliphatic acid amides, NMP (n-methylpyrrolidone), N-alkylated pyrrolidones and corresponding piperidone, methanol and mixtures of dialkethers of polyethylene glycols. The method comprises scrubbing preferably the natural gas with an aqueous solution comprising the above compounds followed by a stripping regeneration step.

Abstract: An absorption medium for removing acid gases from a fluid stream comprises an aqueous solution of a) of at least one metal salt of an aminocarboxylic acid, and b) of at least one acid promoter, wherein the molar ratio of b) to a) is in the range from 0.0005 to 1.0. The acid promoter is selected from mineral acids, carboxylic acids, sulfonic acids, organic phosphonic acids and partial esters thereof. The absorption medium, compared with absorption media based on amino acid salts, has a reduced regeneration energy requirement without significantly reducing the absorption capacity of the solution for acid gases. In a process for removing acid gases from the fluid stream, the fluid stream is brought into contact with the absorption medium.

Abstract: This invention relates to processes for selective removal of contaminants from effluent gases. A sulfur dioxide absorption/desorption process for selective removal and recovery of sulfur dioxide from effluent gases utilizes a buffered aqueous absorption solution comprising weak inorganic or organic acids or salts thereof, to selectively absorb sulfur dioxide from the effluent gas. Absorbed sulfur dioxide is subsequently stripped to regenerate the absorption solution and produce a sulfur dioxide-enriched gas. A process for simultaneous removal of sulfur dioxide and nitrogen oxides (NOx) from effluent gases and recovery of sulfur dioxide utilizes a buffered aqueous absorption solution including a metal chelate to absorb sulfur dioxide and NOx from the gas and subsequently reducing absorbed NOx to form nitrogen. A process to control sulfate salt contaminant concentration in the absorption solution involves partial crystallization and removal of sulfate salt crystals.

Abstract: The present invention relates to nanocomposite materials comprising: graphite-based material dispersed among transition metal-organic framework (MOF) units, wherein the graphite-based material is chemically linked to MOF units; wherein the graphite-based material is present in the range of about 5 wt. % to about 60 wt. % of the composite material.

Abstract: Compositions and associated methods directed to the removal of sulfurous compounds from air are presented herein. The compositions and methods may be able to treat air with H2S concentrations of at least 1000 ppm. The compositions and associated methods are used to remove sulfurous compounds from air associated with wastewater systems in various aspects.

Abstract: Apparatus comprising an absorber device provided with a plurality of sequentially adjacent sections for flowing a gas stream therethrough. A solvent reactable with components of the gas stream is ingressed into and egressed from each section of the absorber device by a conduit infrastructure. The conduit infrastructure has a plurality of heat exchange and cooling equipment, and communicates with solvent recovery and regeneration equipment. A process wherein a liquid solvent selected for reacting with gaseous components, is counter-flowed against the gas stream. The liquid solvent temperature is controllably manipulated between each section of the absorber device to provide: (a) thermodynamic-driven mass transfer at the front end of the absorber device, and (b) kinetic-driven mass transfer at the back end of the absorber device. Heat generated during recovery of gaseous components from the liquid solvent is recovered for use in regenerating the solvent system.

Abstract: An process for efficiently deacidizing a gaseous mixture is described. The process utilizes a self-concentrating absorbent that absorbs an acid gas at reduced overall energy costs for the deacidizing operation.

Abstract: The method allows to remove mercaptans contained in a gaseous feed comprising hydrocarbons by carrying out the following stages: a) contacting, in a reactor R1, gaseous feed 1 with a liquid stream 13 comprising olefins, in the presence of a first acid catalyst so that the mercaptans react with the olefins so as to form sulfides, b) discharging an effluent 3 from reactor R1 and separating the effluent into a gas phase and a liquid phase so as to obtain a mercaptan-depleted treated gas 4 and a sulfide-laden liquid, c) separating the sulfide-laden liquid into a first fraction 6 and a second fraction 5, the volume flow rate of first fraction 6 being at least three times higher than the volume flow rate of second fraction 5, d) recycling first fraction 6 to stage a) as a first portion of said liquid stream to be fed into said reactor R1, e) regenerating second fraction 5 by cracking so as to obtain a sulfide-depleted second fraction 2 that is recycled to stage a) as a second portion of said liquid stream.

Abstract: A method for treating a fluid to be scrubbed, comprising filling a scrubber with a volume of biodiesel or biomass adequate to cover a sintered permeable membrane in the reaction chamber and a bit more to create a reaction zone in not only a plurality of pores in the membrane with fluid but in a reaction zone above the membrane, then introducing fluid to be scrubbed to the membrane, building up pressure in the reaction chamber, and passing a scrubbed fluid from the reaction zone to an exit port at a rate equal to the rate the fluid to be scrubbed is introduced.

Abstract: The invention has as its object a process for the treatment of a gas that contains hydrogen sulfide and sulfurous anhydride, in which: a) The gas (3) is brought into contact with an organic solvent (1) that contains a catalyst in at least one gas-liquid reactor-contactor (2); a gas effluent that contains vapor sulfur and liquid sulfur is recovered separately, b) Said gas effluent is introduced into a first condensation zone (7) that operates at a temperature of between 70 and 100° C. so that the sulfur that is contained in said gas effluent is deposited in solid form on the so-called cold walls of the equipment of the zone (7), c) When the clogging limit of said equipment of zone (7) is reached, said equipment is regenerated so as to melt the solid sulfur that is deposited inside said equipment for obtaining a liquid effluent, d) Said liquid effluent is recycled in the reactor-contactor, e) A purified gas that contains less than 30 ppm by volume of sulfur is extracted from the zone (7).

Abstract: The present invention provides a method for binding gaseous molecules, the method comprising contacting gases comprising the gaseous molecules with trivalent metal complexes. Typically, the gaseous molecules comprise polar molecules of greenhouse gases, especially the oxides of carbon, nitrogen and sulphur. Preferably, the trivalent metal complexes comprise complexes of actinide metals, most preferably uranium. The method is particularly useful in the removal of so-called greenhouse gases from the atmosphere, and is therefore of potentially very great value environmentally. The invention also provides trivalent metal complexes comprising sandwich complexes of trivalent metals selected from transition metals and actinide metals, the complexes comprising two ligands selected from pentalenyl, indenyl, cyclopentadienyl and cyclooctatetraene ligands. The invention further provides a method for the preparation of the trivalent metal complexes.

Abstract: A method for treating gases to be scrubbed, comprising filling a scrubber with a volume of lean liquid adequate to cover a sintered permeable membrane in the reaction chamber and a bit more to create a reaction zone in not only a plurality of pores in the membrane with gases but in a reaction zone above the membrane, then introducing gases to be scrubbed to the membrane, building up pressure in the reaction chamber, and passing scrubbed gas from the reaction zone to an exit port at a rate equal to the rate of gases to be scrubbed are introduced.

Abstract: An improved process for deacidizing a gaseous mixture using phase enhanced gas-liquid absorption is described. The process utilizes a multiphasic absorbent that absorbs an acid gas at increased rate and leads to reduced overall energy costs for the deacidizing operation.

Abstract: The present invention relates generally to the field of emission control equipment for boilers, heaters, kilns, or other flue gas-, or combustion gas-, generating devices (e.g., those located at power plants, processing plants) and, in particular to a new and useful method and apparatus designed to remove and/or capture carbon oxides (e.g., CO2 or CO) from flue gas-, or combustion gas-, generating devices. In another embodiment, the present invention relates to a method for achieving emission control from flue gas-, or combustion gas-, generating devices where the method achieves a reduction in, or the elimination of, carbon oxides or sulfur oxides contained in the flue gas-, or combustion gas-, generating devices.

Abstract: A controller is provided for directing control of a process performed to control an amount of a pollutant emitted into the air. The process has multiple process parameters (MPPs) The controller includes either a neural network process model or a non-neural network process model. Whichever type model is included, it will represent a relationship between one of the MPPs and other of the MPPs. The controller also includes a control processor having the logic to determine the validity of a measured value of the one MPP based on the one model. The control processor directs control of the process in accordance with the measured value of the one MPP only if the measured value of the one MPP is determined to be valid. On the other hand, if the measured value is determined to be invalid, the control processor may direct control of the process in accordance with an estimated value of the one MPP.

Abstract: A composition for removing mercaptan from a gas stream containing at least one acid gas in addition to a mercaptan, the composition comprising a physical and/or chemical solvent for H2S and an inclusion compound for the mercaptan. A process of treating gas stream using the composition. The inclusion compound is selected from the group consisting of, cyclodextrin, cryptand, calixarene. cucurbituril. The chemical solvent may be monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA, diisopropylamine (DIPA), diglycolamine (DGA) and methyldiethanolamine (MDEA). Examples of useful physical solvents include cyclotetramethylene sulfone (sulfolane) and its derivatives, aliphatic acid amides, NMP (n-methylpyrrolidone), N-alkylated pyrrolidones and corresponding piperidone methanol and mixtures of dialkethers of polyethylene glycols. The method copirses scrubbing preferably the natural gas with an aqueous solution comprising the above compounds followed by a stripping regeneration step.

Abstract: A process for purifying CO2 offgas streams to free them of chemical compounds, and to the recycling of the purified gas streams into the production process.