Sorbent compositions having pneumatic conveyance capabilities
View Patent ↗Sorbent compositions including sorbent particles of a small particle sized sorbent with increased pneumatic conveyance properties. The sorbent compositions have relatively small median particle size and have a controlled particle size distribution (PSD). Specifically, the sorbent compositions include a relatively small percentage of very fine particles, such as a small percentage of particles having a particle size of not greater than about 5 μm. The sorbent compositions are particularly useful for the treatment of a flue gas stream to remove mercury from the flue gas stream.
1. A particulate sorbent composition, the particulate sorbent composition comprising porous carbonaceous particles selected from the group consisting of activated carbon, reactivated carbon, carbonaceous char and combinations thereof, wherein the particulate sorbent composition has a median particle size of not greater than about 20 μm, and a particle size distribution wherein not greater than about 10 vol. % of particles comprising the particulate sorbent composition have a particle size of not greater than about 5 μm.
2. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition has a median particle size of not greater than about 18 μm.
3. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition has a median particle size of not greater than about 15 μm.
4. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition has a median particle size of not greater than about 12 μm.
5. The particulate sorbent composition of claim 1 , wherein not greater than about 5 vol. % of the particles comprising the particulate sorbent composition have a particle size of not greater than about 5 μm.
6. The particulate sorbent composition of claim 1 , wherein not greater than about 8 vol. % of the particles comprising the particulate sorbent composition have a particle size of not greater than about 3 μm.
7. The particulate sorbent composition of claim 1 , wherein not greater than about 5 vol. % of the particles comprising the particulate sorbent composition have a particle size of not greater than about 2 μm.
8. The particulate sorbent composition of claim 1 , wherein not greater than about 2 vol. % of the particles comprising the particulate sorbent composition have a particle size of not greater than about 1 μm.
9. The particulate sorbent composition of claim 1 , wherein the porous carbonaceous particles comprise powdered activated carbon.
10. The particulate sorbent composition of claim 9 , wherein the powdered activated carbon is derived from lignite coal.
11. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition has a Basic Flow Energy of at least about 300 mJ.
12. The particulate sorbent composition of any of claim 1 , wherein the particulate sorbent composition has a Basic Flow Energy of at least about 350 mJ.
13. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition has a Specific Energy of at least about 6 mJ/g.
14. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition has a Specific Energy of at least about 6.5 mJ/g.
15. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition has an Aeration Energy of not greater than about 54 mJ.
16. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition has an Aeration Energy of not greater than about 20 mJ.
17. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition has an Aeration Ratio of at least about 9.
18. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition has an Aeration Ratio of at least about 20.
19. The particulate sorbent composition of claim 10 , wherein the particulate sorbent composition has a Conditioned Bulk Density of at least about 0.4 g/m l.
20. The particulate sorbent composition of claim 10 , wherein the particulate sorbent composition has a Conditioned Bulk Density of at least about 0.46 g/ml.
21. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition has a pressure drop as measured by the Permeability test of not greater than about 55 mbar at an applied normal stress of 15 kPa and at an air velocity of 0.5 mm/s.
22. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition has a pressure drop as measured by the Permeability test of not greater than about 40 mbar at an applied normal stress of 15 kPa and at an air velocity of 0.5 mm/s.
23. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition has a Compressibility of not greater than about 24% at an applied normal stress of 15 kPa.
24. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition has a Compressibility of not greater than about 20% at an applied normal stress of 15 kPa.
25. A method for the treatment of a flue gas stream emanating from a boiler, comprising the step of contacting the flue gas stream with the particulate sorbent composition recited in claim 1 .
26. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition further comprises a halogen-containing compound.
27. A particulate sorbent composition, the particulate sorbent composition comprising porous carbonaceous particles selected from the group consisting of activated carbon, reactivated carbon, carbonaceous char and combinations thereof, wherein the particulate sorbent composition has a median particle size of not greater than about 12 μm, and a particle size distribution wherein not greater than about 10 vol. % of particles comprising the particulate sorbent composition have a particle size of not greater than about 5 μm, and wherein the particulate sorbent composition further comprises a halogen-containing compound.
28. The particulate sorbent composition of claim 27 , wherein the porous carbonaceous particles comprise powdered activated carbon.