Methods of manufacturing mercury sorbents and removing mercury from a gas stream
Sorbents for removal of mercury and other pollutants from gas streams, such as a flue gas stream from coal-fired utility plants, and methods for their manufacture and use are disclosed. The methods include injecting a sorbent consisting essentially of recovered and separated fluid cracking catalyst particles into a flue gas stream.
1. A method of removing mercury and other pollutants from a flue gas stream comprising injecting a sorbent consisting essentially of recovered and separated fluid cracking catalyst (FCC) particles into the flue gas stream.
2. The method of claim 1 , wherein the FCC particles are fine particles.
3. The method of claim 2 , wherein the FCC particles contain essentially no added metal sulfides on the surface of the particles.
4. The method of claim 2 , wherein the FCC particles have an average particle diameter of less than about 40 microns.
5. The method of claim 4 , wherein the FCC particles have an average particle diameter in the range of about 20 microns to about 40 microns.
6. The method of claim 4 , wherein the FCC particles have an average particle diameter of less than about 20 microns.
7. The method of claim 1 , wherein the FCC particles contain at least one of zeolite, hydrous kaolin, metakaolin, sodium silicate, silica, and alumina.
8. The method of claim 7 , wherein the content of each component is in the range from zero to 100% by weight.
9. The method of claim 7 , wherein the zeolite is a y-type zeolite.
10. The method of claim 7 , wherein the FCC particles are obtained from an intermediate stage of an FCC manufacturing process.
11. The method of claim 10 , wherein the FCC particles are separated by one or more of a centrifuge, settling and filtration.
12. The method of claim 10 , wherein the FCC particles are obtained prior to ion exchange.
13. The method of claim 10 , wherein the FCC particles are obtained after ion exchange.
14. The method of claim 10 , wherein the FCC particles are obtained prior to calcination.
15. The method of claim 10 , wherein the FCC particles are obtained after calcination.
16. The method of claim 1 , wherein the flue gas stream originates from a coal-fired boiler.
17. The method of claim 1 , wherein the flue gas stream originates from an oil-fired boiler.
18. The method of claim 1 , wherein the flue gas stream originates from municipal waste combustion.
19. The method of claim 1 , wherein the flue gas stream originates from a medical waste incinerator.