Chemical process
View Patent ↗A process for the removal of azide ions from aqueous liquids at alkaline pH by alkali-soluble metals and catalyst or by hydrogen and catalyst.
1. A catalytic, non-electrolytical process for the removal of azide ions from aqueous liquids comprising treating an azide ion containing aqueous liquid at an alkaline pH with (a) one or more alkali-soluble metals and a catalyst, or with (b) hydrogen and a catalyst.
2. The process as defined in claim 1 wherein the one or more alkali-soluble metals comprise aluminum and zinc.
3. The process as defined in claim 1 wherein the catalyst is nickel.
4. The process as defined in claim 1 wherein the azide ion containing aqueous liquid is alkalinized by addition of an inorganic base to produce the alkaline pH.
5. The process as defined in claim 1 wherein the azide ion containing aqueous liquid has the alkaline pH.
6. The process as defined in claim 1 wherein the one or more alkali-soluble metals and the catalyst is selected from the group consisting of an aluminium-nickel mixture and an aluminium-nickel alloy.
7. The process as defined in claim 1 wherein the process is carried out at a temperature between +5° C. and +40° C.
8. The process as defined in claim 1 wherein the azide ion containing aqueous liquid is an aqueous solution.
9. The process as defined in claim 4 wherein the inorganic base is sodium hydroxide.
10. The process as defined in claim 1 wherein the process is carried out under a hydrogen atmosphere where hydrogen is formed during the dissolution of a metal.
11. The process as defined in claim 1 wherein the process is carried out at a pressure between atmospheric pressure and 60 bar, under a hydrogen atmosphere.
12. The process as defined in claim 1 wherein the azide ion containing aqueous liquid contains more than 90 mass % of water and the treatment at the alkaline pH is with the one or more alkali soluble metals and the catalysts.