Method and apparatus for on-site production of lime and sorbents for use in removal of gaseous pollutants
AssigneeThe Board of Trustees of the University of Illinois
InventorsRamsay Chang, Yongqi Lu, Massoud Rostam-Abadi
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Abstract
The invention provides various methods for removing gas phase pollutants by calcining limestone or dolomite using flash calcination to produce a high surface area lime or hydrated lime and directly adding the lime or hydrated lime to a gas stream containing gas phase pollutants. In other methods, the production of an activated sorbent, such as activated carbon, is combined with the production of the high surface area lime or hydrated lime and directly added to a gas stream containing gas phase pollutants. The combination of lime or hydrated lime and an activated sorbent enhances the removal of gas phase pollutants such as those from a coal-fired boiler flue gas.
Claims31
A method for removing at least one gaseous pollutant from a gas stream, comprising:
- adding a calcium-based sorbent to a chamber;
- feeding a carbonaceous material into the chamber concurrently with said adding of said calcium-based sorbent to the chamber;
- suspending said calcium-based sorbent in the chamber;
- calcining said calcium-based sorbent in the chamber to produce suspended lime at a controllable temperature and residence time;
- activating said carbonaceous material to produce an activated sorbent using steam activation;
- feeding said suspended lime from the chamber into a separate gas duct comprising a gas stream comprising at least one gaseous pollutant;
- and
- reacting said lime with said at least one gaseous pollutant to remove said at least one gaseous pollutant from the gas phase of said gas stream.
A method for removing gaseous contaminants from a gas stream, comprising:
- adding a calcium-based sorbent to a chamber;
- suspending said calcium-based sorbent in the chamber;
- calcining said calcium-based sorbent in the chamber to produce suspended lime;
- hydrating said suspended lime to produce suspended hydrated lime;
- feeding said suspended hydrated lime into a gas stream comprising at least one gaseous contaminant;
- and
- reacting said hydrated lime with said at least one gaseous contaminant to remove said at least one gaseous contaminant from the gas phase of said gas stream.
Dependencies are inferred from the claim text.