Union Carbide Corporation

Uop Lcc

Alexander J Kosseim

Gilbert R Atwood

Joseph E Sokolik, Jr

David Arthur Dunnery

Ervine S Holmes

Daniel J Kubek

John G McCullough

Kenneth J Barr

Processes are disclosed for purifying hydrocarbon feedstreams, e.g, natural gas, to remove carbonyl sulfide and other acid gases such as carbon dioxide and hydrogen sulfide. The processes employ a conversion step to convert carbonyl sulfide to hydrogen sulfide and carbon dioxide followed by an absorption step to remove the carbon dioxide and hydrogen sulfide from the feedstream. Carbonyl sulfide is converted to carbon dioxide and hydrogen sulfide in the presence of an aqueous alkaline solution which preferably has the same composition as the absorption solution used in the absorption step.

Processes for removing carbonyl sulfide from hydrocarbon feedstreams

In an alkanolamine gas treating process for removing acid gas from a feedstream in which hydrogen sulfide is present, reduced corrosion of steel parts or components is observed when solution concentrations of hydrogen sulfide and vanadium in the plus five valence state are maintained above certain minimum levels.

Alkanolamine gas treating process for a feedstream containing hydrogen

A regenerable process for scrubbing SO.sub.2 from effluent gases using an aqueous alkanolamine and the corresponding sulfite as the solvent, such amine having a boiling point below about 250.degree. C. at one atmosphere pressure and wherein the alkanolamine solutions containing heat stable salts (HSS) is regenerated by alkali addition, crystallization and vacuum distillation of the amine.

Regenerable process for the selective removal of sulfur dioxide from

Method for scrubbing SO.sub.2 from effluent gases using aqueous monoethanolamine and the corresponding sulfite as the solvent. The method is especially useful where the effluent gases contain an abundance of CO.sub.2 relative to SO.sub.2.

Process for the selective removal of sulfur dioxide from effluent gases

Improvement in processes for the selective removal of sulfur dioxide with respect to carbon dioxide from a gas mixture containing same wherein the gas mixture is contacted with an aqueous absorbent solution, such as alkanolamine, alkali metal hydroxide, ammonium hydroxide or sulfites thereof, to remove sulfur dioxide from the gas mixture and form a SO.sub.2 -rich aqueous absorbent solution which is moved to a stripping zone where sulfur dioxide is driven off to form a SO.sub.2 -depleted aqueous absorbent solution which is recycled and re-contacted with the gas mixture, the improvement comprising removing sulfur oxyanions of heat stable salts which accumulate in the aqueous absorbent solution by contacting a portion of it with an anion exchange resin having hydroxyl anions displaceable by the heat stable sulfur oxyanions whereby the hydroxyl anions of the resin are replaced by the heat stable divalent sulfur oxyanions which are thus taken out of the solution. The anion exchange resin preferably is a strong base anion exchange resin which can be regenerated by contacting it with aqueous sodium hydroxide to replace the heat stable sulfur oxyanions on said resin with hydroxyl anions.

Process for removing SO.sub.2 from effluent gases and for removing heat

Improvement in processes for the selective removal of sulfur dioxide with respect to carbon dioxide from a gas mixture containing same wherein the gas mixture is contacted with an aqueous absorbent solution, such as an alkanolamine, an alkali metal or ammonium hydroxide, or sulfites thereof, to remove sulfur dioxide from the gas mixture and form a SO.sub.2 -rich aqueous absorbent solution which is moved to a stripping zone where sulfur dioxide is driven off to form a SO.sub.2 -depleted aqueous absorbent solution which is recycled and re-contacted with the gas mixture, the improvement comprising removing sulfur oxyanions of heat stable salts which accumulate in the aqueous absorbent solution by contacting it with an anion exchange resin having bisulfite anions displaceable by the heat stable sulfur oxyanions whereby the bisulfite anions of the resin are replaced by the heat stable divalent sulfur oxyanions which are thus taken out of the solution. The anion exchange resin preferably is a weak base anion exchange resin which can be regenerated by contacting it with aqueous ammonium hydroxide to replace the heat stable sulfur oxyanions on said resin with hydroxyl anions and thereafter contacting the resin with aqueous-sulfur dioxide to replace the hydroxyl anions with bisulfite anions.

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Rye, NY, United States of America

Alexander J Kosseim