Sorbent compositions having pneumatic conveyance capabilities
View Patent ↗A sorbent composition such as for the removal of a contaminant species from a fluid stream, a method for manufacturing a sorbent composition and a method for the treatment of a flue gas stream to remove heavy metals such as mercury (Hg) therefrom. The sorbent composition includes a porous carbonaceous sorbent such as powdered activated carbon (PAC) and a solid particulate additive that functions as a flow-aid to enhance the pneumatic conveyance properties of the sorbent composition. The solid particulate additive may be a flake-like material, for example a phyllosilicate minerals or graphites.
1. A sorbent composition comprising a free-flowing particulate blend of:
at least about 50 wt. % powdered activated carbon sorbent having a median particle size (D50) of at least about 5 μm and not greater than about 15 μm; and
at least about 0.1 wt. % and not greater than about 12 wt. % of a solid particulate phyllosilicate additive.
2. The sorbent composition recited in claim 1 , wherein the solid particulate additive comprises talc.
3. The sorbent composition recited in claim 1 , wherein the solid particulate additive comprises mica.
4. The sorbent composition as recited in claim 3 , wherein the sorbent composition comprises at least about 2 wt. % mica and not greater than about 7 wt. % mica.
5. The sorbent composition recited in claim 1 , wherein the sorbent composition has a Specific Energy of not greater than about 7.5 mJ/g.
6. The sorbent composition recited in claim 1 , wherein the sorbent composition has an Aeration Energy of not greater than about 35 mJ.
7. The sorbent composition recited in claim 1 , wherein the sorbent composition has a basic flow energy of not greater than about 300 mJ.
8. The sorbent composition recited in claim 1 , wherein the solid particulate additive has a median aspect ratio of not greater than 0.7.
9. The sorbent composition recited in claim 1 , wherein the solid particulate additive has a median circularity of not greater than about 0.92.
10. The sorbent composition recited in claim 1 , wherein the solid particulate additive has a median elongation factor of at least 0.3.
11. The sorbent composition recited in claim 1 , wherein the powdered activated carbon has a median particle size of not greater than about 12 μm.
12. A sorbent composition comprising a particulate blend of:
at least about 50 wt. % powdered activated carbon sorbent having a median particle size (D50) of at least about 5 μm and not greater than about 15 μm; and
at least about 2 wt. % and not greater than about 7 wt. % mica.
13. The sorbent composition recited in claim 2 , wherein the talc has a median particle size (D50) of from about 12 μm to about 27 μm.