Methods of operating a coal burning facility
AssigneeNOx II, Ltd.
InventorDouglas C Comrie
Life of this patent
Estimating the term…
Abstract
Methods involve adding sorbent components, such as calcium oxide, alumina, and silica, as well as optional halogens as part of environmental control. Use of the sorbents leads to significant reductions in sulfur and mercury emissions that otherwise would result from burning coal. Use of the sorbents leads to production of waste coal ash that, while higher in mercury, is nevertheless usable as a commercial product because the mercury in the ash is non-leaching and because the coal ash has a higher cementitious nature by virtue of the increased content of the sorbent components in the ash. Thus, the methods involve adding powders having qualities that lead to the production of a cementitious coal ash while at the same time reducing emissions from a coal burning facility.
Claims28
A method of increasing the value of coal burned in a coal burning facility, the method comprising:
- combusting coal containing mercury in the presence of at least one sorbent to produce heat energy, ash, and flue gases, said ash containing at least 90% by weight of the mercury originally present in the coal, said ash having a concentration of acid leachable mercury that is less than a concentration of acid leachable mercury in an ash produced by combusting the coal without the at least one sorbent;
- monitoring said flue gases for said mercury and adjusting the presence of the at least one sorbent to achieve a desired mercury emission to comply with an environmental regulation;
- and
- realizing a monetary savings by an avoidance of disposal costs of said fly ash produced.
A method of operating a coal burning facility comprising:
- combusting coal in a furnace and in the presence of a sorbent composition;
- and
- generating energy by the combusting coal;
- wherein said sorbent composition is at least one of added onto said coal prior to said combusting, applied into said furnace during said combusting and applied into flue gases downstream of said furnace,
- wherein said presence of said sorbent composition reduces emissions of at least one of mercury and sulfur compared to combusting coal without said sorbent composition, and
- wherein said presence of said sorbent composition produces a coal ash more cementitious in nature compared to a coal ash produced from combusting coal without said presence of said sorbent composition.
A method of operating a coal plant to produce energy and waste ash, the method comprising:
- burning coal in the presence of a sorbent composition to produce a waste ash with a reduced concentration of acid leachable mercury when compared to the concentration of acid leachable mercury in the waste ash produced from burning coal without the sorbent composition;
- recovering the waste ash having a reduced concentration of acid leachable mercury;
- and
- mixing it with cementitious powder to make a cement product.
A method of operating a coal burning plant to produce heat energy and fly ash, the method comprising:
- burning coal in the presence of at least one sorbent that increases a concentration of a heavy metal in the fly ash and that decreases a concentration of acid leachable heavy metal in the fly ash when compared to the concentration of heavy metal and the concentration of acid leachable heavy metal in the fly ash produce by burning the coal without said at least one sorbent;
- and
- selling said fly ash as an industrial raw material.
Dependencies are inferred from the claim text.