A process is presented where a feed stream containing a hydrogen sulfide and another feed component is introduced into an absorber that the feed stream flows upward from the bottom of the absorber and contacts a liquid treatment solution, where the liquid treatment solution contains a sulfur dye catalyst. The hydrogen sulfide is absorbed into the liquid treatment solution and converted into sulfide ions. The other feed component is removed from the absorber vessel substantially free of the hydrogen sulfide and a spent treatment solution is also removed from the absorber vessel and fed to an oxidation vessel where it is contacted with an oxygen containing gas causing the sulfide ions to oxidize to thiosulfate and converting the spent sulfur dye catalyst to regenerated sulfur dye catalyst. The thiosulfate is recovered, and the regenerated sulfur dye catalyst can be recycled as part of the liquid treatment solution.

A process is presented where a feed stream containing a hydrogen sulfide and another feed component is introduced into an absorber that the feed stream flows upward from the bottom of the absorber and contacts a liquid treatment solution, where the liquid treatment solution contains a sulfur dye catalyst. The hydrogen sulfide is absorbed into the liquid treatment solution and converted into sulfide ions. The other feed component is removed from the absorber vessel substantially free of the hydrogen sulfide and a spent treatment solution is also removed from the absorber vessel and fed to an oxidation vessel where it is contacted with an oxygen containing gas causing the sulfide ions to oxidize to thiosulfate and converting the spent sulfur dye catalyst to regenerated sulfur dye catalyst. The thiosulfate is recovered, and the regenerated sulfur dye catalyst can be recycled as part of the liquid treatment solution.

The invention provides a process for the production of hydrogen, comprising catalytically decomposing a concentrated aqueous solution of potassium formate in a reaction vessel to form bicarbonate slurry and hydrogen, discharging the hydrogen from said reaction vessel, and treating a mixture comprising the bicarbonate slurry and the catalyst with an oxidizer, thereby regenerating the catalyst. Pd/C catalysts useful in the process are also described.

The invention provides a process for the production of hydrogen, comprising catalytically decomposing a concentrated aqueous solution of potassium formate in a reaction vessel to form bicarbonate slurry and hydrogen, discharging the hydrogen from said reaction vessel, and treating a mixture comprising the bicarbonate slurry and the catalyst with an oxidizer, thereby regenerating the catalyst. Pd/C catalysts useful in the process are also described.

The present invention provides techniques that selectively recover Re from reductive amination catalysts. In particular, the present invention allows Re to be recovered selectively relative to Ni, Co, and/or Cu, and particularly Ni, that are often present on reductive amination catalysts. The present invention uses a combination of oxidation and extraction techniques to selectively recover Re relative to Ni, Co, and/or Cu. Advantageously, the recovery is selective even when using aqueous solutions for extraction.

The present invention provides techniques that selectively recover Re from reductive amination catalysts. In particular, the present invention allows Re to be recovered selectively relative to Ni, Co, and/or Cu, and particularly Ni, that are often present on reductive amination catalysts. The present invention uses a combination of oxidation and extraction techniques to selectively recover Re relative to Ni, Co, and/or Cu. Advantageously, the recovery is selective even when using aqueous solutions for extraction.

A process is presented where a feed stream containing a hydrogen sulfide and another feed component is introduced into an absorber that the feed stream flows upward from the bottom of the absorber and contacts a liquid treatment solution, where the liquid treatment solution contains a sulfur dye catalyst. The hydrogen sulfide is absorbed into the liquid treatment solution and converted into sulfide ions. The other feed component is removed from the absorber vessel substantially free of the hydrogen sulfide and a spent treatment solution is also removed from the absorber vessel and fed to an oxidation vessel where it is contacted with an oxygen containing gas causing the sulfide ions to oxidize to thiosulfate and converting the spent sulfur dye catalyst to regenerated sulfur dye catalyst. The thiosulfate is recovered, and the regenerated sulfur dye catalyst can be recycled as part of the liquid treatment solution.

A process is presented where a feed stream containing a hydrogen sulfide and another feed component is introduced into an absorber that the feed stream flows upward from the bottom of the absorber and contacts a liquid treatment solution, where the liquid treatment solution contains a sulfur dye catalyst. The hydrogen sulfide is absorbed into the liquid treatment solution and converted into sulfide ions. The other feed component is removed from the absorber vessel substantially free of the hydrogen sulfide and a spent treatment solution is also removed from the absorber vessel and fed to an oxidation vessel where it is contacted with an oxygen containing gas causing the sulfide ions to oxidize to thiosulfate and converting the spent sulfur dye catalyst to regenerated sulfur dye catalyst. The thiosulfate is recovered, and the regenerated sulfur dye catalyst can be recycled as part of the liquid treatment solution.

The invention provides a process for the production of hydrogen, comprising catalytically decomposing a concentrated aqueous solution of potassium formate in a reaction vessel to form bicarbonate slurry and hydrogen, discharging the hydrogen from said reaction vessel, and treating a mixture comprising the bicarbonate slurry and the catalyst with an oxidizer, thereby regenerating the catalyst. Pd/C catalysts useful in the process are also described.

The invention provides a process for the production of hydrogen, comprising catalytically decomposing a concentrated aqueous solution of potassium formate in a reaction vessel to form bicarbonate slurry and hydrogen, discharging the hydrogen from said reaction vessel, and treating a mixture comprising the bicarbonate slurry and the catalyst with an oxidizer, thereby regenerating the catalyst. Pd/C catalysts useful in the process are also described.