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US 10,760,026 B2Granted
Enzyme treatment of coal for mercury remediation
AssigneeNOx II, Ltd.
InventorMurray Abbott
Life of this patent
Estimating the term…
Abstract
Emissions of mercury, NOx, and/or SOx are reduced by enzyme treating coal before combustion, optionally with further treatment of the coal with certain non-bromine containing powder sorbents. y using the steps together, mercury can be reduced by 40% or more, and NOx by 20% or more. Advantageously, no bromine is introduced with the remediation steps.
Claims21
A method of burning coal to reduce emissions of mercury and nitrogen oxides (NOx), comprising:
- treating coal with an enzyme composition comprising an enzyme and a pH buffer by applying the enzyme composition onto the coal and reacting for a time period to make an enzyme treated coal;
- combusting the enzyme treated coal in the presence of a single powder sorbent composition comprising silica, alumina, and calcium in the furnace of a coal burning facility to create heat energy and flue gases to reduce mercury emissions by at least 40% relative to mercury emissions and NOx emissions by at least 20% relative to NOx emissions achieved when coal is combusted without the enzyme treatment and without using the single powder sorbent composition, wherein the single powder sorbent composition comprises one or more components selected from the group consisting of:
- an aluminosilicate clay, calcium-containing aluminosilicate minerals, Portland cement, cement kiln dust (CKD), clinker, cement kiln feed, transition cement, clinker grind outs, limestone, lime, lime kiln dust, sugar beet lime, slag, calcium oxide, calcium hydroxide, montmorillonite, sodium montmorillonite, kaolin, and combinations thereof, wherein the single powder sorbent composition is the only sorbent composition used before, during, or after the combusting and wherein no additional halogens or halogen-containing compounds are added;
- measuring the amount of mercury in the flue gases;
- and
- adjusting the treating step if the measured amount of mercury is above or below a target level,
- wherein the enzyme composition comprises water and the enzyme at a pH at which the enzyme is active.
4 more elements
A method for reducing mercury and nitrogen oxides (NOx) emissions from a coal burning plant, comprising:
- enzyme treating the coal by applying an enzyme and pH buffer;
- and
- applying a single powder sorbent composition comprising silica, alumina, and calcium to the enzyme treated coal;
- combusting the enzyme treated coal in the presence of the single powder sorbent composition to reduce mercury emissions of the coal burning plant by at least 40% as compared to mercury emissions and NOx emissions by at least 20% relative to NOx emissions achieved when coal is combusted without the enzyme treating and without using the single powder sorbent composition, wherein the single powder sorbent composition comprises one or more components selected from the group consisting of:
- an aluminosilicate clay, calcium-containing aluminosilicate minerals, Portland cement, cement kiln dust (CKD), clinker, cement kiln feed, transition cement, clinker grind outs, limestone, lime, lime kiln dust, sugar beet lime, slag, calcium oxide, calcium hydroxide, montmorillonite, sodium montmorillonite, kaolin, and combinations thereof and the single powder sorbent composition is the only sorbent composition used before, during, or after the combusting and wherein no additional halogens or halogen-containing compounds are added.
2 more elements
A method of burning coal to reduce emissions of mercury and nitrogen oxides (NOx), comprising:
- treating coal with an enzyme composition comprising an enzyme, a pH buffer, and water, the enzyme composition having a pH at which the enzyme is active and applied onto the coal at greater than or equal to about 1 to less than or equal to about 10 part per million (ppm) of coal and reacting for a time period to make an enzyme treated coal;
- combusting the enzyme treated coal in the presence of a single powder sorbent composition comprising silica, alumina, and calcium added to the enzyme-treated coal at a rate of greater than or equal to about 0.1 to less than or equal to about 1% by weight in the furnace of a coal burning facility to create heat energy and flue gases to reduce mercury emissions by at least 40% relative to mercury emissions and nitrogen oxides (NOx) emissions by at least 20% relative to NOx emissions achieved when coal is combusted without the enzyme treatment and without using the single powder sorbent composition, wherein the single powder sorbent composition comprises one or more components selected from the group consisting of:
- an aluminosilicate clay, calcium-containing aluminosilicate minerals, Portland cement, cement kiln dust (CKD), clinker, cement kiln feed, transition cement, clinker grind outs, limestone, lime, lime kiln dust, sugar beet lime, slag, calcium oxide, calcium hydroxide, montmorillonite, sodium montmorillonite, kaolin, and combinations thereof and the single powder sorbent composition is the only sorbent composition used before, during, or after the combusting and wherein no additional halogens or halogen-containing compounds are added;
- and
- measuring the amount of mercury in the flue gases;
- and
- adjusting the treating step if a measured amount of mercury is above or below a target level.
4 more elements
Dependencies are inferred from the claim text.