Sorbent
A method for preparing a sorbent composition includes the steps of: (i) applying, from a solution or a slurry, a layer of a copper compound on the surface of a support material, and (ii) drying the coated support material, wherein the thickness of the copper compound layer on the dried support is in the range 1-200 μm. The precursor may be converted to a sorbent suitable for removing heavy metals from liquids or gases by applying one or more sulphur compounds to sulphide the copper compound and form CuS.
1. A method for preparing a sorbent composition comprising the steps of:
(i) forming a slurry of basic copper carbonate and a binder material and milling the slurry,
(ii) applying a layer of a copper compound on an exterior surface of a support material by dipping or spraying the support material with the slurry of basic copper carbonate to form a coated support material and
(iii) drying the coated support material to form a dried support having a shell comprising the copper compound,
wherein the thickness of the shell on the dried support is in the range 1-200 μm and wherein the sorbent composition comprises 0.5 to 20% by weight of copper.
2. A method according to claim 1 wherein the thickness of the shell on the dried support is in the range 1 to 150 micrometers.
3. A method according to claim 1 wherein the support material comprises an alumina, hydrated alumina, titania, zirconia, silica or aluminosilicate, or a mixture of two or more of these.
4. A method according to claim 1 wherein the support material is an alumina.
5. A method according to claim 1 wherein the support material is in the form of a foam, monolith or honeycomb or a coating on a structured packing.
6. A method according to claim 1 wherein the support material is in the form of shaped particulate unit selected from the group consisting of spheres, rings, trilobes, quadralobes, and cylinders.
7. A method according to claim 1 wherein the support material has a BET surface area of 10-330 m 2 ·g −1 and a pore volume in the range 0.3-0.9 cm 3 ·g −1 .
8. A method according to claim 1 wherein the slurry is at a pH in the range 5 to 9.
9. A method according to claim 1 comprising a step of calcining the dried support to convert the copper compound to copper (II) oxide.
10. A method according to claim 1 further comprising applying one or more sulphur compounds to the shell to effect sulphidation of the copper to form copper (II) sulphide.
11. A method according to claim 10 wherein the sulphur compound is hydrogen sulphide.
12. A method according to claim 1 wherein the sorbent comprises 0.75-10% by weight of copper.
13. A method according to claim 1 wherein the layer of copper compound is applied to the exterior surface of the support material by spraying.
14. A method according to claim 1 wherein the support material is in the form of a shaped particulate unit with a diameter or width in the range 1-10 mm.
15. A method for preparing a sorbent composition comprising the steps of:
(i) applying a layer of a copper compound on an exterior surface of a support material by dipping or spraying the support material with a slurry of basic copper carbonate to form a coated support material, the support material being in the form of a shaped particulate unit selected from the group consisting of spheres, rings, trilobes, quadralobes, and cylinders and
(ii) drying the coated support material to form a dried support having a shell in the form of the shaped particulate unit, the shell comprising the copper compound,
wherein the thickness of the shell on the dried support is in the range 1-200 μm and wherein the sorbent composition comprises 0.5 to 20% by weight of copper.
16. A method according to claim 15 wherein the thickness of the shell on the dried support is in the range 1 to 150 micrometers.
17. A method according to claim 15 wherein the support material comprises an alumina, hydrated alumina, titania, zirconia, silica or aluminosilicate, or a mixture of two or more of these.
18. A method according to claim 15 wherein the support material has between 2 and 10 holes extending therethrough.
19. A method according to claim 15 wherein the support material has a BET surface area of 10-330 m 2 ·g −1 and a pore volume in the range 0.3-0.9 cm 3 ·g −1 .
20. A method according to claim 15 wherein the slurry is at a pH in the range 5 to 9.
21. A method according to claim 15 comprising a step of calcining the dried support to convert the copper compound to copper (II) oxide.
22. A method according to claim 15 further comprising applying one or more sulphur compounds to the shell to effect sulphidation of the copper to form copper (II) sulphide.