Sorbent compositions having pneumatic conveyance capabilities
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, wherein the particulate sorbent composition has a median particle size of not greater than about 20 μm, and a particle size distribution and wherein, in the particle size distribution, 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 median particle size is not greater than about 18 μm.
3. The particulate sorbent composition of claim 1 , wherein the median particle size is not greater than about 15 μm.
4. The particulate sorbent composition of claim 1 , wherein the median particle size is not greater than about 14 μm.
5. The particulate sorbent composition of claim 1 , wherein the median particle size is not greater than about 12 μm.
6. 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.
7. The particulate sorbent composition of claim 1 , wherein the porous carbonaceous particles are selected from the group consisting of activated carbon, reactivated carbon, carbonaceous char, and combinations thereof.
8. The particulate sorbent composition of any 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 4 μm.
9. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition has a Basic Flow Energy of at least about 300 mJ.
10. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition has a Specific Energy of at least about 6 mJ/g.
11. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition has an Aeration Energy of not greater than about 54 mJ.
12. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition has an Aeration Ratio of at least about 20.
13. The particulate sorbent composition of any of claim 1 , wherein the particulate sorbent composition has a Conditioned Bulk Density of at least about 0.4 g/ml.
14. The particulate sorbent composition of any of claim 1 , wherein the particulate sorbent composition has a pressure drop as measured by a 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.
15. The particulate sorbent composition of any 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.
16. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition further comprises a halogen-containing compound.
17. The particulate sorbent composition of claim 16 , wherein the halogen-containing compound is a halogen salt comprising an anionic group and a cationic group, wherein the anionic group is selected from the group consisting of bromides, bromates, hypobromites, iodides, iodates, hypoiodites, chlorides, chlorates, hypochlorites, and combinations thereof, and the cationic group is selected from the group consisting of an alkali metal, an alkaline earth metal, and a combination thereof.
18. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition further comprises an acid gas agent.
19. The particulate sorbent composition of claim 18 , wherein the acid gas agent is selected from the group consisting of alkali oxides, alkaline earth oxides, hydroxides, carbonates, bicarbonates, phosphates, silicates, aluminates, and combinations thereof.
20. The particulate sorbent composition of claim 1 , wherein the particulate sorbent composition further comprises a flow agent.
21. A particulate sorbent composition, the particulate sorbent composition comprising porous carbonaceous particles and a halogen compound, wherein the particulate sorbent composition has a median particle size of not greater than about 20 μm and a particle size distribution, and wherein, in the particle size distribution, not greater than about 10 vol. % of particles comprising the particulate sorbent composition have a particle size of not greater than about 5 μm.
22. A particulate sorbent composition, the particulate sorbent composition comprising porous carbonaceous particles, wherein the particulate sorbent composition has a median particle size of not greater than about 20 μm and a particle size distribution, wherein, in the particle size distribution, 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 one or more of the following is true:
(i) the particulate sorbent composition has a Basic Flow Energy of at least about 300 mJ;
(ii) the particulate sorbent composition has a Specific Energy of at least about 6 mJ/g;
(iii) the particulate sorbent composition has an Aeration Energy of not greater than about 54 mJ;
(iv) the particulate sorbent composition has an Aeration Ratio of at least about 20;
(v) the particulate sorbent composition has a Conditioned Bulk Density of at least about 0.4 g/ml;
(vi) the particulate sorbent composition has a pressure drop as measured by a 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; and
(vii) the particulate sorbent composition has a Compressibility of not greater than about 24% at an applied normal stress of 15 kPa.
23. The particulate sorbent composition of claim 22 , wherein the particulate sorbent composition further comprises a halogen-containing compound.
24. The particulate sorbent composition of claim 22 , wherein (i) is true.
25. The particulate sorbent composition of claim 22 , wherein (ii) is true.
26. The particulate sorbent composition of claim 22 , wherein (iii) is true.
27. The particulate sorbent composition of claim 22 , wherein (iv) is true.
28. The particulate sorbent composition of claim 22 , wherein (v) is true.
29. The particulate sorbent composition of claim 22 , wherein (vi) is true.
30. The particulate sorbent composition of claim 22 , wherein (vii) is true.