Abstract: An exhaust gas cleaning system comprises a first sub system including a scrubber unit comprising a scrubber arranged to wash the exhaust gas with a scrubber fluid, and a centrifugal separator arranged in communication with the scrubber unit for receiving the scrubber fluid after washing and separate it into a first and a second fraction, which second fraction is more polluted than the first fraction. The exhaust gas cleaning system further comprises a second sub system including a membrane filter arranged in communication with the centrifugal separator for receiving the first fraction output from the centrifugal separator and separating it into a third and a fourth fraction, which fourth fraction is more polluted than the third fraction. A method for cleaning exhaust gas onboard a ship involves cleaning an exhaust gas onboard a ship.

Abstract: A method for sorbing a gas using an ionic liquid to sorb a vapor having an electric multi-pole moment. The ionic liquid comprises an anion and a cation. The electric multi-pole moment may be an electric dipole moment and/or an electric quadru-pole moment. The sorption may be an adsorption or an absorption. The ionic liquid may be a liquid that substantially contains only anions and cations, while not containing other components, such as water. Alternatively, a solution containing the ionic liquid and a solvent or further compound, such as water, may be used.

Abstract: A water recovery process for a steam assisted gravity drainage system for a heavy oil recovery facility, the process comprising a flash drum and a flash drum heat exchanger/condenser, wherein the water recovery process receives hot water produced by a facility at a temperature above the water atmospheric boiling point and cools it to a temperature below the water atmospheric boiling point before transferring it to the remaining section of the water recovery process.

Abstract: A method for removal of a compound from a crude hydrocarbon gas stream to be obtained from a sub-sea well is disclosed. The method comprises bringing the crude hydrocarbon gas stream in contact with a treatment solution comprising an absorbent at least partly selective to the compound to be removed, thereby obtaining a rich treatment solution and a compound depleted gas stream, regenerating the treatment solution comprising the absorbent by desorbing the compound from the rich treatment solution, thereby obtaining a compound stream.

Abstract: Disclosed is an aqueous solution for absorbing and recovering carbon dioxide from a carbon dioxide-containing gas, the aqueous solution containing an amino alcohol compound represented by Formula I and an amine compound represented by Formula 2, wherein R represents an alkyl group having 1 to 5 carbon atoms; and n represents 1 or 2, wherein X represents —NR1R2; Y represents —NR3R4; R1, R2, R3 and R4 may be the same or different, and each represents an alkyl group having 1 to 3 carbon atoms; and m represents an integer of 3 to 7.

Abstract: The present application relates to a system for removal of gaseous contaminants from a gas stream. The system includes an absorber for contacting the gas stream with a wash solution to form a used wash stream, a regenerator for regenerating the used wash solution, a reboiler and at least two heat exchangers in fluid communication with the absorber, regenerator and reboiler.

Abstract: The present invention relates to methods and systems for improving the utilization of energy in a cement manufacturing plant comprising an absorption based contaminant, e.g. CO2, capture process using thermal regeneration of a liquid absorbent. The methods and systems of the present invention are characterized in that the thermal regeneration of the liquid absorbent is at least partially effected using a hot exhaust gas stream generated in the kiln of the cement manufacturing plant.

Abstract: A slug-containing vapor recovery system wherein pressure and/or fluid level sensors are provided which monitor for conditions caused by the entry of a slug of hydrocarbon liquid, including that caused by a plunger-lift system. The system can be configured to accommodate virtually any anticipated slug-events.

Abstract: A method and system for removing gaseous contaminants from a gas stream by contacting the gas stream with a wash solution and regenerating the wash solution in a regeneration system for future use in removing gaseous contaminants from the gas stream.

Abstract: The present application relates to systems and processes for removal of gaseous contaminants from gas streams. In particular, the application relates to a process for removal of gaseous contaminants from a gas stream comprising contacting the gas stream with a wash solution to remove gaseous contaminants from the gas stream by absorption into the wash solution; and regenerating the used wash solution to remove gaseous contaminants from the used wash solution, to provide a regenerated wash solution and a gas comprising removed contaminants, wherein in a first regeneration stage the gas comprising removed contaminants is cooled to minimize loss of water vapor from the regeneration step.

Abstract: A process for the recovery of an amine acid gas absorbent used in an acid gas recovery unit, comprising obtaining an amine-containing waste stream from a heat stable salt (HSS) removal unit wherein a HSS containing amine acid gas absorbent stream is contacted with a base and subjected to a first phase separation step whereby a light regenerated amine absorbent stream and the amine-containing waste stream are produced; contacting the amine-containing waste stream with an organic solvent and obtaining an amine rich organic solvent stream and an amine reduced waste stream; and contacting the amine rich organic solvent stream with an acid and obtaining a protonated amine stream and an amine reduced organic solvent stream.

Abstract: The present invention relates to a process for the recovery of ammonia contained in a gaseous stream, said process comprising the following phases: (a) subjecting the gaseous stream containing ammonia to a washing with an aqueous washing solution having a pH lower than 7.0, with the formation of a purified gaseous stream and an aqueous solution containing an ammonium salt; (b) treating the aqueous solution containing the ammonium salt coming from phase (a) in a vertical falling film heat exchanger at a temperature from 50 to 250° C. and an absolute pressure ranging from 50 KPa to 4 MPa with the formation of a regenerated washing solution and a gaseous stream comprising NH3 and H2O; (c) recycling said regenerated washing solution to phase (a). The present invention also relates to equipment for effecting the above process.

Abstract: In some implementations, a method for dehydrating carbon dioxide includes identifying a stream including at least carbon dioxide and water. At least a portion of the stream is dehydrated using an initial lean sorbent including glycerol and a polyhydric alcohol to generate dry carbon dioxide stream and rich sorbent including water. The polyhydric alcohol reduces an amount of glycerol lost to the dry carbon dioxide stream during dehydration. This process may result in the beneficial reduction in the amount of glycerol that leaves the system with the dry carbon dioxide. The dry carbon dioxide and the rich sorbent are separated. The glycerol is recycled by dehydrating the rich sorbent to produce recycled lean sorbent.

Abstract: A two-stage process for upgrading a gaseous stream containing CO2 and H2S in which the gaseous stream and pressurized water are provided to a first stage absorption process in which a portion of the CO2 is absorbed by the pressurized water. The reduced-CO2 gaseous stream and a chemical solvent suitable for absorbing CO2 and H2S are provided to a second stage absorption process in which the H2S and remaining CO2 are removed from the gaseous stream, producing an acid gas stream and an upgraded gaseous stream meeting pipeline-quality specifications.

Abstract: The present invention describes a method for recovery of high purity carbon dioxide, which is substantially free of nitrogen oxides. This high purity carbon dioxide is obtained by introducing into the method a step in which carbon dioxide absorbed in an absorbing agent is flashed. The present invention also discloses a plant for recovery of said high purity carbon dioxide comprising an absorption column, a flash column, a stripper column, and a down stream purification unit comprising a washing column, a dehydrator, a condenser and a distillation unit.

Abstract: A method for recovering carbon dioxide (CO2) from a gas stream is disclosed. The method includes the step of reacting CO2 in the gas stream with fine droplets of a liquid absorbent, so as to form a solid material in which the CO2 is bound. The solid material is then transported to a desorption site, where it is heated, to release substantially pure CO2 gas. The CO2 gas can then be collected and used or transported in any desired way. A related apparatus for recovering carbon dioxide (CO2) from a gas stream is also described herein.

Abstract: A system for the thermal conditioning of a fluid, more particularly a drilling mud, in Preparation for subsequent cycles of analysis of the composition of the fluid. The system provides for the presence of at least one generator of microwaves for heating the fluid, and a cylinder of non-stick material. The fluid flows through the cylinder such that the heating of the mud takes place in less than 70 seconds.

Abstract: A modular amine plant having a front-end module and a back-end module in fluid communication with each other. The front-end module having pre-fabricated connections for the association of various equipment including: a filter, an absorption tower, and a flash tank. The back-end module having pre-fabricated connections for the association of other various equipment including: a heat exchanger, a distillation tower, and a reboiler. The modular amine plant capable of being installed at a site in less than about 5 days. The modular amine plant further having moment forces sufficient to withstand wind speeds of about 100 miles per hour.

Abstract: To include an absorber (1006) that brings CO2 absorbent that absorbs CO2 contained in flue gas (1002) into contact with the flue gas to remove CO2 from the flue gas, a regenerator (1008) that strips CO2 from CO2 absorbent (rich solution), which is fed from the absorber through a first feed line L1 and has absorbed CO2, to regenerate CO2 absorbent, thereby acquiring regenerated CO2 absorbent (lean solution) (1009), falling film reboilers (1101-1 and 1101-2) that draw off CO2 absorbent (amine solution) (1033) from near the bottom of the regenerator and reheats regenerated CO2 absorbent via steam (1031), a first liquid-vapor separator (1103) that separates the CO2 absorbent reheated by the falling film reboilers into regenerated CO2 absorbent in which CO2 has been removed and vapor containing CO2, and a second feed line L2 for supplying the separated regenerated CO2 absorbent to the absorber.

Abstract: The present invention provides a gas pressurized separation system to strip a product gas from a liquid stream and yield a high pressure gaseous effluent containing the product gas. The system comprises a gas pressurized stripping apparatus, such as a column, with at least one first inlet allowing flow of one or more liquid streams in a first direction and at least one second inlet allowing flow of one or more high pressure gas streams in a second direction, to strip the product gas into the high pressure gas stream and yield through at least one outlet a high pressure gaseous effluent containing the product gas; and two or more heat supplying apparatuses provided at different locations along the column. Processes for separating a product gas from a gaseous mixture to yield a high pressure gaseous effluent containing the product gas, utilize the gas pressurized separation system described above.

Abstract: Systems and processes for reducing the energy requirements of an ammonia recovery stripper in a chilled ammonia-based CO2 removal system. The systems and processes include a nanofiltration or reverse osmosis unit for physically separating the washed liquid from a wash vessel configured to receive an ammonia slip feed stream from the main absorber of the chilled ammonia-based CO2 removal system and provide first and second feed streams. Relative to the washed liquid from the wash vessel, the first feed stream has a decreased ammonia molarity whereas the second feed stream has an increased ammonia molarity. The second feed stream is then fed to the ammonia recovery stripper, which reduces steam consumption. The reduced steam consumption translates to significant energy savings, among numerous other advantages. Additionally, the systems and process provide a reduction of equipment sizes related to the stripper unit as may be desired in some applications.

Abstract: Some embodiments described herein relate to ionic liquids comprising an anion of a heteraromatic compound such as optionally substituted pyrrolide, optionally substituted pyrazolide, optionally substituted indolide, optionally substituted phospholide, or optionally substituted imidazolide. Methods and devices for gas separation or gas absorption related to these ionic liquids are also described herein.

Abstract: A method for processing pre-combustion syngas includes, in an exemplary embodiment, providing an absorber unit having a membrane contactor having a plurality of micro-pores, channeling pre-combustion syngas along a first surface of the membrane contactor, channeling an amine based solvent along a second opposing surface of the membrane contactor, and contacting the solvent with the syngas such that the solvent and the syngas contact at gas-liquid interface areas, defined by the plurality of micro-pores in the membrane contactor, to separate CO2 from the flue gas by a chemical absorption of CO2 into the solvent to produce a solvent containing CO2.

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 system (10) for regenerating a rich absorbent solution (26), the system including: an absorber (20) facilitating interaction between a process stream (22) and an absorbent solution, wherein the process stream comprises an acidic component, and interaction of the process stream with the absorbent solution produces a reduced acidic component stream (28) and a rich absorbent solution; at least one heat exchanger accepting at least one of said reduced acidic component stream and the process stream to transfer heat to a heat transfer fluid (60); and at least one mechanism (60a) to transfer the heat transfer fluid from said at least one heat exchanger to a regenerator (34) regenerating the rich absorbent solution, wherein each of the at least one mechanisms is fluidly coupled to each of the at least one heat exchangers.

Abstract: Disclosed is a measurement device with which it is possible to quickly measure the carbon dioxide content of an absorbent solution circulating through a carbon dioxide recovery system.

Abstract: A CO2 recovery system includes an absorption tower and a regeneration tower. CO2 rich solution is produced in the absorption tower by absorbing CO2 from CO2-containing gas. The CO2 rich solution is conveyed to the regeneration tower where lean solution is produced from the rich solution by removing CO2. A compressor compresses CO2 that is removed from the rich solution and discharged through a head of the regeneration tower. Heat is generated while the compressor compresses the CO2. A heat supplying unit supplies the heat to the regeneration tower for heating the lean solution.

Abstract: This invention relates to a method and plant for energy-efficient removal of CO2 from a gas phase by means of absorption. The invention is particularly suitable for use in connection with thermal power plants fired by fossil fuels, and is also well-suited for retrofitting in existing thermal power plants. A processing plant according to the invention comprises three sections: a primary CO2-generating process that serves as main product supplier; a CO2-capture and separation plant based on absorption and desorption of CO2 respectively by/from at least one absorbent; and a second CO2-generating process where combustion of carbonaceous fuel in pure oxygen atmosphere serves as energy supply to at least a part of the thermal energy necessary to drive the regeneration of the absorbent in the desorption column(s).

Abstract: Methods of using microchannel separation systems including absorbents to improve thermal efficiency and reduce parasitic power loss. Energy is typically added to desorb methane and then energy or heat is removed to absorb methane using a working solution. The working solution or absorbent may comprise an ionic liquid, or other fluids that demonstrate a difference in affinity between methane and nitrogen in a solution.

Abstract: A solution contained in a regeneration tower is supplied to a filtering unit. The filter unit filters out solid particles contained in the solution. A washing unit washes out with backwash water solid particles filtered out by the filter unit. An evaporating unit receives the backwash water containing the solid particles, and heats received backwash water thereby obtaining solid-particles concentrated backwash water.

Abstract: An absorption medium for removing acid gases from a fluid stream comprises an aqueous solution of A) at least one cyclic amine compound having solely tertiary amine groups and/or sterically hindered secondary amine groups and B) at least one cyclic amine compound having at least one sterically unhindered secondary amine group. The absorption medium comprises, e.g., an aqueous solution of A) 1-hydroxyethylpiperidine and/or triethylenediamine and B) piperazine. The absorption medium is particularly suitable for separating off carbon dioxide from flue gases and satisfies the following criteria: (i) sufficient capacity at low CO2 partial pressures; (ii) sufficiently rapid absorption rate at low CO2 partial pressures; (iii) stability toward oxygen; (iv) low vapor pressure for reducing solvent losses; and (v) low energy requirement for regeneration of the absorption medium.

Abstract: The present invention relates to a process for removing carbon dioxide and optionally hydrogen sulphide and/or COS from a gas stream containing these compounds by washing the gas with an aqueous washing solution containing water, sulfolane and a secondary or tertiary amine derived from ethanolamine. More particularly the invention relates to the process described above, the process being carried out in the presence of a primary or secondary amine compound in an amount between 0.5 and 15 wt. % based on water, sulfolane and amine. The invention further relates to an absorbent liquid to be used in the above process.

Abstract: A CO2 reducing system (10A) is constituted by a low-temperature CO2 reducing apparatus (11-1) that includes a low-temperature absorber (1006-1) that reduces at least one of CO2 and H2S by bringing flue gas (1002) including at least one of CO2 and H2S into contact with a low-temperature absorbing solution (1005-1), a low-temperature regenerator (1008-1) that regenerates a low-temperature rich solution (1007-1), a low-temperature rich-solution supply line (12-1) that feeds the low-temperature rich solution (1007-1) to the low-temperature regenerator (1008-1), and a low-temperature lean-solution supply line (13-1) that feeds a low-temperature lean solution (1009-1) to the low-temperature absorber (1006-1) from the low-temperature regenerator (1008-1); and a high-temperature CO2 reducing apparatus (11-2) that is arranged on a side at which the flue gas (1002) is discharged, and that has the same configuration as the low-temperature CO2 reducing apparatus (11-1).

Abstract: Methods of using microchannel separation systems including absorbents to improve thermal efficiency and reduce parasitic power loss. Energy is typically added to desorb a solute and then energy or heat is removed to absorb a solute using a working solution. The working solution or absorbent may comprise an ionic liquid, or other fluids that demonstrate a difference in affinity between a solute and other gases in a solution.

Abstract: The natural gas arriving through pipe 1 is deacidified by being brought into contact with a solvent in zone C. The solvent charged with acid compounds is regenerated in zone R. The acid gases, released into pipe 5 upon regeneration, include a quantity of solvent. The method enables the solvent contained in the acid gases to be extracted. In zone ZA, the acid gases are brought into contact with a non-aqueous ionic liquid whose general formula is Q+ A?, where Q+ designates an ammonium, phosphonium, and/or sulfonium cation, and A? designates an anion able to form a liquid salt. The solvent is removed from the acid gases evacuated through pipe 6. The ionic liquid charged with solvent is regenerated by heating in an evaporator DE. The ionic liquid regenerated is recycled through pipes 8 and 9 to zone ZA. The solvent is evacuated through pipe 13.

Abstract: A method for processing flue-gas, in an exemplary embodiment, includes providing an absorber unit having a membrane contactor, channeling a combustion flue gas along a first surface of the membrane contactor, and channeling an ammonia-based liquid reagent along a second opposing surface of the membrane contactor. The method also includes partially separating the ammonia-based liquid from the flue gas such that the ammonia-based liquid and the flue gas contact at gas-liquid interface areas, defined by a plurality of pores of the membrane contactor, to separate CO2 from the flue gas by a chemical absorption of CO2 within the ammonia-based liquid to produce a CO2-rich ammonia-based liquid.

Abstract: A plant for producing silicon thin-film solar cells has at least one chamber (1) in which the silicon thin-film is deposited from silicon hydride gas during the production process. The chamber (1) is subsequently cleaned of contaminants by an etching process e.g. with sulfur hexafluoride as the etchant gas. The waste gas formed during the production process and containing silicon hydride is supplied to a burner (6) and subsequently filtered. The waste gas formed during the etching process and containing sulfur hexafluoride is washed with water after having been supplied to a burner. The hydrofluoric acid formed by burning of the sulfur hexafluoride is separated from the washing water.

Abstract: In a process for deacidifying a fluid hydrocarbon stream which comprises carbon dioxide (CO2) and/or other acid gases as impurities, the fluid stream is brought into intimate contact with an absorption liquid in an absorption or extraction zone (12), the substantially purified fluid stream and the absorption liquid which is loaded with CO2 and/or other acid gases are separated from one another, and the absorption liquid is subsequently regenerated and then again fed to the absorption extraction zone (12). To regenerate the absorption liquid, the loaded absorption liquid is first expanded in a first low-pressure expansion stage (22) to a pressure of from 1 to 2 bar (absolute). The partially regenerated absorption liquid is then heated in a heat exchanger (20) and then, in a second low-pressure expansion stage (29), again expanded to a pressure of from 1 to 2 bar (absolute).

Abstract: An improved method and apparatus for oxidizing undesired compounds residing within a liquid glycol based absorbent wherein the compounds are heated within a reboiler chamber to their boiling point to effectuate production of vaporized effluents. The absorbent's vaporized effluents rise upwardly exiting the reboiler chamber and enter a reflux tower wherein they are partially condensed via a condenser embodied within the interior of the tower. The residual uncondensed effluents are then transported to and first heated via a vaporizer/heat exchanger, thus effectuating the vaporization of any ambient condensed liquids contained within the effluents. The revaporized effluents then enter the invention's thermal oxidizer combustion chamber where they are second heated to a temperature necessary to effectuate destruction of undesirable compounds, such as but not limited to benzene, toluene and xylene.

Abstract: A process for the removal of water from gas which comprises an absorption step of bringing a gas (1) saturated with water vapour into gas-liquid contact with a water-lean absorbing liquid (3) comprising a water absorbing liquid having a cloud point temperature above the freezing point of water whereby water vapour present in the gas is absorbed into the water-lean absorbing liquid at a temperature below its cloud point to produce a refined gas (4) having a reduced water vapour content and water-loaded absorbing liquid (5); and a regeneration step of heating the water-loaded absorbing liquid (5) to above the cloud point temperature of the absorbing liquid whereby the water-loaded absorbing liquid separates into a water-rich phase (7) and an absorbing liquid-rich phase (8) and cooling the absorbing liquid-rich phase to a temperature below its cloud point prior to recycling the absorbing liquid-rich phase for use as water-lean absorbing liquid (3) in the absorption step.

Abstract: An object of the present invention is to carry out separation recovery of ammonia efficiently from a gaseous mixture containing ammonia and carbon dioxide, without generating a solid ammonium carbamate. A recovery method of ammonia from a gaseous mixture, includes a process (I) in which a gaseous mixture containing ammonia and carbon dioxide is contacted with an organic solvent to allow the organic solvent to absorb ammonia in the gaseous mixture, and a process (II) in which the organic solvent which absorbed ammonia is distilled to separate ammonia from the organic solvent.

Abstract: The invention is directed to a process for the separation of one or more gaseous components from a gas stream, in which the gas stream is brought into contact with a layer arrangement on a first side and the liquid absorbent is in contact with a second side opposite to the first side, wherein said layer arrangement has a dense polymeric coating layer with a fractional free volume in the range of 20-45% on a porous carrier layer. The invention is also directed to a process for the desorption of the gaseous components from the liquid absorbent, as well an apparatus for the separation of the gaseous component and an apparatus for the desorption of the gaseous component.

Abstract: The present invention provides a process for the recovery of unreacted ammonia from the effluent obtained from a reaction zone wherein oxygen, ammonia and a hydrocarbon are reacted at an elevated temperature in the presence of an ammoxidation catalyst to produce an unsaturated nitrile is provided, including the steps of:

Abstract: A glycol regenerating system wherein a pressurized reboiler is introduced to a typical prior art system, the pressurized reboiler being in the glycol stream upstream from the conventional atmospheric reboiler. The pressurized reboiler heats the rich glycol coming from the glycol contactor from about 300° F. to 400° F. and keeps the glycol under pressure from about 10-25 psig. in order to first distill and condense VOCs (volatile organic compounds) which constitute non-condensable hydrocarbons and condensable hydrocarbons such as BTEX (Benzene, Toluene, Ethylbenzene, Xylene) compounds, the components being conveniently under pressure for transporting the components to a desired location.

Abstract: A process of separating water from ambient air involves a liquid desiccant to first withdraw water from air and treatment of the liquid desiccant to produce water and regenerated desiccant. Water lean air is released to the atmosphere. Heat generated in the process is recycled. The drying capacity, or volume of water produced, of the system for a given energy input is favored over the production of dried air.

Abstract: Method for recovering oxygen from a medium containing O.sub.2 using polynitrogenated compounds that have five coordinating functions which are capable of binding a metal atom, particularly a cobalt atom. In the recovery method, oxygen is first absorbed by the metal complex and then desorbed from the complex and recovered in an appropriate vessel.

Abstract: The present invention relates to a method for removing high molecular weight high melting point hydrocarbon vapors from a hydrocarbon vapor offgas stream produced during the liquefaction of a solid waste plastic material to produce an oil that serves as a liquid feedstock for a partial oxidation reaction. The hydrocarbon vapor offgas stream is directly contacted with a water spray at a condensation temperature above the melting point of the high molecular weight hydrocarbons contained in the offgas. This results in the condensation and convenient removal of the high melting point hydrocarbons, referred to as "waxes." One or more subsequent condensation steps can be conducted at lower condensation temperatures to remove the lower temperature condensable hydrocarbons. The remaining uncondensed vapors are then recycled to serve as a heater fuel for the liquefaction of the waste plastic material.

Abstract: A method and apparatus for extracting hydrocarbon gas from drilling fluid samples utilizes microwave energy as the source for heating a sample, containing water, sufficiently to cause the extraction of the hydrocarbon gases therefrom. Either a batch or a continuous operation can be realized using this method.

Abstract: A gaseous mixture containing chlorine, carbon dioxide and non-condensable gas is compressed and cooled to separate it into a residual gas formed principally of a major portion of the non-condensable gas and a condensate formed primarily of chlorine. The condensate is fed to a stripping column to desorb carbon dioxide and a minor portion of the non-condensable gas dissolved in the condensate. The stripped gas formed primarily of chlorine and carbon dioxide may be treated further. Namely, the stripped gas is mixed with the residual gas. At least a portion of the mixed gas is fed into an absorption column, whereby a major portion of remaining chlorine is absorbed to lower the chlorine content Removal of chlorine from such a gaseous mixture or an off-gas from the above process can be achieved by washing it with an aqueous solution or suspension containing an alkali metal sulfite and/or an alkaline earth metal sulfite while controlling the pH of the solution or suspension within a range of 1.9-6.3.