In a broad form the present invention relates to a method for oxidation of a species comprising sulfur in an oxidation state below +4, such as H.sub.2S, CS.sub.2, COS and S.sub.8 vapor, to SO.sub.2 said method comprising the step of contacting the gas and an oxidant with a catalytically active material consisting of one or more elements taken from the group consisting of V, W, Ce, Mo, Fe, Ca, Mg, Si, Ti and Al in elemental, oxide, carbide or sulfide form, optionally with the presence of other elements in a concentration below 1 wt %, at a temperature between 180° C. and 290° C., 330° C., 360° C. or 450° C., with the associated benefit of such a temperature being highly energy effective, and the benefit of said elements having a low tendency to form sulfates under the conditions, with the related benefit of an increased stability of the catalytically active material. The other elements present may be catalytically active noble metals or impurities in the listed materials.

An absorbent for the selective removal of hydrogen sulfide from a fluid stream comprising carbon dioxide and hydrogen sulfide, wherein the absorbent contains an aqueous solution, comprising: a) an amine or a mixture of amines of the general formula (I) wherein R.sup.1 is C.sub.1-C.sub.5-alkyl; R.sup.2 is C.sub.1-C.sub.5-alkyl; R.sup.3 is selected from hydrogen and C.sub.1-C.sub.5-alkyl; x is an integer from 2 to 10; and b) an ether or a mixture of ethers of the general formula (II): R.sup.4—[O—CH.sub.2—CH.sub.2].sub.y—OH; wherein R.sup.4 is C.sub.1-C.sub.5-alkyl; and y is an integer from 2 to 10; wherein R.sup.1 and R.sup.4 are identical; wherein the mass ratio of b) to a) is from 0.08 to 0.5. The absorbent is suitable for the selective removal of hydrogen sulfide from a fluid stream comprising carbon dioxide and hydrogen sulfide. The absorbent has a reduced tendency for phase separation at temperatures falling within the usual range of regeneration temperatures for the aqueous amine mixtures and is easily obtainable. ##STR00001##

The invention relates to a method for preparing a solid comprising the mixture of a set of compounds comprising at least one Cu.sub.2(OH).sub.2CO.sub.3 powder, one metal oxide powder selected from the group of metals consisting of copper, zinc, iron, manganese and mixtures thereof, and at least one binder as well as the use of the solid prepared by means of this method.

Provided is a process that may comprise cooling an engine exhaust emissions comprising SO.sub.x on a vehicle that may come from an engine. The cooled engine exhaust emissions comprising SO.sub.x may be passed to one or more absorption units. The SO.sub.x may be extracted from the engine exhaust emissions with a sorbent supported on solid porous media in an absorption unit on the vehicle to form an absorbed SO.sub.x. The absorbed SO.sub.x may be desorbed, followed by forming one or more SO.sub.x product from the desorbed SO.sub.x. The one or more SO.sub.x product may be unloaded to an off-vehicle facility.

Disclosed are embodiments of a method of regenerating a desiccant in an off-line treater of a polyolefin production process. The method may include a heating phase followed by a cooling phase. The heating phase may involve use of a regenerating gas made from heating a treated a recycle stream of the polyolefin production process to regenerate desiccant in an off-line treater. The cooling phase may involve thermosyphoning the regenerating gas, nitrogen, an olefin-free diluent, or combinations thereof in a closed-convection loop of the off-line treater.

A low pressure re-absorber is integrated with a sulfur-rich solvent flash drum or a sulfur-rich solvent stripping column in a solvent acid gas removal process that provides for sufficient sulfur concentration for the downstream sulfur recovery unit. In another aspect of the invention, carbon dioxide containing or carbon dioxide rich gas streams that are at a lower temperature relative to a lean solvent stream are used to cool those lean solvent streams and then optionally to cool other process streams, to save energy consumption.

The present invention relates to an improved method for removing contaminants from a gaseous stream substantially comprising carbon dioxide. More specifically, the method comprises the step of subjecting the gaseous stream to an absorption step in which the absorbent is liquid carbon dioxide wherein the waste of carbon dioxide is minimized by utilizing a compressing means for generating a pressure difference between two streams in a reboiler.

The present invention concerns a process for removing carbon monoxide and/or gaseous sulphur compounds from hydrogen gas and/or aliphatic hydrocarbons, preferably at low temperatures, with the aid of complex metal aluminium hydrides.

Coating a hydrogel-state coating liquid containing at least a hydrophilic compound and an acid gas carrier on one surface of a hydrophobic porous body having three-dimensional network structure formed through intersecting, coupling or branching of a plurality of fibrils, and a large number of pores formed of microscopic interstices divided by the plurality of fibrils to form a facilitated transport membrane thereon. The hydrophobic porous body has an average inter-fibril distance of 0.001 μm or more and 2 μm or less inside a plane in parallel to a surface on which the acid gas separation facilitated transport membrane is formed, an average fibril length of 0.01 μm or more and 2 μm or less inside the plane, and an average inter-fibril distance of 0.001 μm or more and 2 μm or less in a direction perpendicular to the surface.

A method of obtaining helium from a process gas. The process gas is at a pressure less than 15 bar to a first membrane separation stage having a first membrane more readily permeable for helium than for at least one other component in the process gas. A first retentate stream is fed to a second membrane separation stage having a second membrane more readily permeable for helium than for at least one other component in the process gas. Helium is separated from a first helium-containing permeate stream using a pressure swing adsorption to obtain a helium-containing product stream. A second helium-containing permeate stream is recycled to the first membrane separation stage. A purge gas from the pressure swing adsorption is also recycled to the first membrane separation stage.