Methyl iodide adsorber, use thereof and method for the adsorption of methyl iodide

1. An iodide or iodine adsorber, comprising a zeolite containing at least one iodide- or iodine-adsorbing metal or a compound thereof, wherein the zeolite is a hydrophobic zeolite having an SiO 2 /Al 2 O 3 ratio>30, and wherein the zeolite is BEA.

2. The adsorber according to claim 1 ,

in which the zeolite is an intrinsically hydrophobic zeolite.

3. The adsorber according to claim 1 ,

in which the zeolite is microporous.

4. The adsorber according to claim 1 ,

in which the zeolite or the adsorber has a proportion of micropores of more than 70%, relative to the total pore volume of the zeolite or of the adsorber.

5. The adsorber according to claim 1 ,

in which the zeolite is an aluminium silicate.

6. The adsorber according to claim 1 ,

in which at least one promoter is contained for reducing the water decomposition by the iodide-adsorbing metal.

7. The adsorber according to claim 6 ,

in which the promoter comprises lead.

8. The adsorber according to claim 1 , in which the zeolite or the adsorber has a BET surface area of 10 to 1000 m 2 /g.

9. The adsorber according to claim 1 ,

in which the adsorber is formed as bulk material.

10. The adsorber according to claim 9 ,

in which the adsorber is formed as extrudate, as shaped bodies or as particles coated with the zeolite.

11. A method for the adsorption of gaseous methyl iodide, gaseous radioactive methyl iodide, gaseous iodine and/or gaseous radioactive iodine, comprising contacting gaseous methyl iodide, gaseous radioactive methyl iodide, gaseous iodine and/or gaseous radioactive iodine with the adsorber of claim 1 .

12. The method according to claim 11 ,

in which the adsorber is used in or in the vicinity of nuclear power plants, reprocessing plants or fuel element storage facilities; and/or

in which the adsorber is used together with a hydrogen recombination catalyst.

13. A process for the adsorption of gaseous methyl iodide, in which gaseous methyl iodide is brought into contact with an adsorber according to claim 1 .

14. A process according to claim 13 ,

in which the gaseous methyl iodide is radioactive; and/or

in which gaseous iodine and/or gaseous radioactive iodine is additionally adsorbed by the adsorber.

15. The adsorber according to claim 1 , wherein the iodide or iodine is adsorbed from a gas phase onto said zeolite.

16. The adsorber according to claim 1 , wherein the zeolite has an SiO 2 /Al 2 O 3 ratio>50.

17. The adsorber according to claim 1 , wherein the iodide- or iodine-adsorbing metal is selected from silver, yttrium, cerium, magnesium, sodium, tin, and lead.

18. The adsorber according to claim 1 , wherein the iodide-adsorbing metal is situated in the pores of the zeolite.

19. The adsorber according to claim 1 , wherein the zeolite has an SiO 2 /Al 2 O 3 ratio>100.

20. The adsorber according to claim 6 , wherein the content of iodide- or iodine-adsorbing metal in the zeolite or in the adsorber is 0.1 to 50 wt. %.

21. The adsorber according to claim 6 , wherein the content of promoter in the zeolite or in the adsorber is 1 to 30 wt. %.

22. The adsorber according to claim 1 , wherein the integral pore volume of the zeolite or of the adsorber is greater than 100 mm 3 /g.

23. The adsorber according to claim 1 , wherein the adsorber comprises a support comprising the zeolite.

24. The adsorber according to claim 1 wherein the adsorber comprises a support wherein the support comprises a washcoat comprising the zeolite.

25. The adsorber according to claim 9 , wherein the adsorber is formed as extrudate, as shaped bodies, or as particles coated with the zeolite.

26. The adsorber according to claim 24 , wherein the adsorber is formed as extrudate, as shaped bodies or as particles coated with the zeolite.

27. The adsorber according to claim 9 wherein the adsorber is formed honey-combed-shaped or plate-shaped.

28. The adsorber according to claim 24 wherein the adsorber is formed honey-combed-shaped or plate-shaped.

29. The adsorber according to claim 9 wherein the support is formed honey-combed-shaped or plate-shaped.

30. The adsorber according to claim 24 wherein the support is formed honey-combed-shaped or plate-shaped.

31. An iodide or iodine adsorber, comprising a BEA zeolite comprising between 10% and 20% of at least one metal or compound thereof capable of methyl-iodide adsorption, wherein the metal or compound thereof is selected from the group consisting of silver, yttrium, cerium, magnesium, sodium, tin and lead; and wherein the BEA zeolite has a ratio of SiO 2 /Al 2 O 3 between 100 and 250, and is microporous.

32. The iodide or iodine adsorber according to claim 31 , wherein the metal or compound thereof is silver.

33. The iodide or iodine adsorber according to claim 31 , further comprising at least one promoter for reducing the water decomposition by the iodide-adsorbing metal, wherein the promotor comprises lead.

34. The iodide or iodine adsorber according to claim 31 , wherein a ratio of the at least one metal or compound thereof capable of methyl-iodide adsorption to the lead is from 6:1 to 1:1.