Sorbents

1. A sorbent suitable for removing mercury from fluid streams comprising 20-75% by weight of copper (expressed as copper (II) oxide) in the form of granules comprising one or more copper sulphide, a support and a binder, said sorbent having a sulphur to copper atomic ratio in the range 0.7 to 0.95:1, wherein the sorbent is formed by:

(i) combining a copper oxide or copper hydroxycarbonate with one or more binders and a support material in a granulator to form a granulated sorbent precursor,

(ii) sulphiding the sorbent precursor with a gas mixture comprising 0.5-5% by volume hydrogen sulphide at a temperature in the range of 1-150° C. to form a sulphided copper material, and

(iii) partially reducing the sulphided copper material to a lower oxidation state with a hydrogen gas mixture containing 20-80% H 2 by volume at a temperature in the range 150-350° C. for 5-24 hours to form the sorbent.

2. A sorbent according to claim 1 , wherein the copper content of the sorbent is in the range of 20-40% by weight.

3. A sorbent according to claim 1 , wherein the S:Cu atomic ratio of the sorbent is in the range of 0.8-0.95.

4. A sorbent according to claim 1 , wherein the binder is a clay, cement or organic polymer binder, or a mixture thereof.

5. A sorbent according to claim 1 , wherein the support material is alumina, hydrated alumina, metal-aluminate, silica, titania, zirconia, zinc oxide, an aluminosilicate, a zeolite, metal carbonate, or carbon, or a mixture thereof.

6. A sorbent according to claim 1 further comprising one or more zinc compounds.

7. A method for the production of a sorbent comprising 20-75% by weight of copper (expressed as copper (II) oxide) in the form of granules comprising one or more copper sulphides, a support and a binder, said sorbent having a sulphur to copper atomic ratio in the range 0.7 to 0.95:1, comprising the steps of:

(i) making a sorbent precursor comprising an oxide or hydroxycarbonate of copper by either applying a layer of a copper compound on the surface of a shaped support material by dipping or spraying the shaped support material with a slurry of copper compound, and drying the coated support material; or by combining an oxide or hydroxycarbonate of copper, with one or more binders and a support material

(ii) sulphiding the sorbent precursor with a gas mixture comprising 0.5-5% by volume hydrogen sulphide at a temperature in the range 1-150° C. to form a sulphided copper material, and

(iii) partially reducing the sulphided copper material to a lower oxidation state with a hydrogen gas mixture containing 20-80% H2 by volume at a temperature in the range 150-350° C. for 5-24 hrs to form the sorbent,

wherein the sorbent precursor or sorbent is shaped.

8. A method according to claim 7 wherein the sulphiding stage is carried out with hydrogen sulphide in an inert gas at a H 2 S concentration in the range 0.5 to 5% by volume.

9. A method according to claim 7 wherein the reduction temperature is in the range 175-300° C.

10. A process for the removal of mercury from a process fluid stream by contacting the fluid stream with the sorbent according to claim 1 .

11. A process for the removal of mercury from a process fluid stream by contacting the fluid stream with the sorbent prepared according to the method of claim 7 .

12. A sorbent according to claim 2 wherein the S:Cu atomic ratio of the sorbent is in the range 0.8-0.9.

13. A method according to claim 9 wherein the reduction temperature is in the range 200-250° C.