Nitrogenous sorbent for coal combustion
First Claim
1. A method for reducing the amount of mercury in combustion gases resulting from burning of mercury containing coal, comprising introducing a sorbent composition into the combustion gases in a zone where the temperature is greater than 500°
- C., wherein the sorbent composition comprises an effective amount of a nitrogenous component selected from the group consisting of a nitrate salt, a nitrite salt, and a combination of a nitrate salt and a nitrite salt.
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Accused Products
Abstract
Sorbent compositions for coal contain nitrogenous components that reduce the level of mercury and/or sulfur emitted into the atmosphere upon combustion. The sorbent compositions are added directly to the fuel before combustion; directly into the fireball during combustion; are added to the fuel before combustion and into the flue gas post combustion zone; or are added completely into the flue gas post combustion zone, preferably where the flue gas temperature is at least 500° C. The sorbent compositions comprise a source of nitrate ions, a source of nitrite ions, or a combination of nitrate and nitrite sources. The sorbents are added as solids or as solutions in water. In various embodiments, the sorbent compositions further comprise a source of halogen such as bromide.
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Citations
27 Claims
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1. A method for reducing the amount of mercury in combustion gases resulting from burning of mercury containing coal, comprising introducing a sorbent composition into the combustion gases in a zone where the temperature is greater than 500°
- C., wherein the sorbent composition comprises an effective amount of a nitrogenous component selected from the group consisting of a nitrate salt, a nitrite salt, and a combination of a nitrate salt and a nitrite salt.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for operating a fuel burning facility to reduce the amount of mercury released from the facility during combustion of a mercury containing fuel, the method comprising
injecting a sorbent composition comprising a nitrate salt and/or a nitrite salt into flue gases where the temperature of the flue gas is in the range of 1500° - F. to 2300°
F.,monitoring the level of mercury in the flue gases downstream of the sorbent injection point, and adjusting the rate of sorbent addition to achieve capture of 90% or greater of the mercury in the mercury containing fuel before emission from the fuel burning facility. - View Dependent Claims (11, 12, 13)
- F. to 2300°
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14. A method for reducing sulfur and/or mercury emissions resulting from the combustion of coal in the furnace of a coal-burning system, comprising
burning the coal in the presence of a nitrite salt and/or a nitrate salt, measuring the mercury level in flue gases resulting from the combustion, comparing the measured mercury level to a target level for emissions, and adjusting the level of addition of nitrite and/or nitrate salt depending on the measured mercury level.
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16. A method for burning coal with decreased emissions of mercury, comprising
combusting coal in a coal burning system to produce flue gases and ash; -
adding calcium nitrate and calcium nitrite into the coal burning system during combustion, measuring the level of mercury in the flue gases, and adjusting the amount of calcium nitrate and calcium nitrite added into the coal burning system depending on the measured level of mercury. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24)
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25. A method of burning carbonaceous mercury containing fuel in a fuel burning facility to reduce the amount of mercury released from the facility, the method comprising
combusting the fuel in the fuel burning system; -
adding calcium nitrate and calcium nitrite into the fuel burning system during combustion; measuring a level of mercury in the flue gases resulting from the combustion; and adjusting the amount of calcium nitrite and calcium nitrate added into the coal burning system depending on the level of measured mercury. - View Dependent Claims (26, 27)
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Specification