Abstract: The description relates to a process for reducing acid plume from stacks from coal-fired combustors operating at varying loads, which have typically been treated by back-end calcium carbonate (limestone) which has not been able to effectively control visible acid plume as power is ramped up from low load. According to the process, as high sulfur and high iron coals are burned in a combustor, magnesium hydroxide slurry is introduced into hot combustion gases in or near the combustion zone. And, during ramp up to high load from a period of operation at low load, additional magnesium hydroxide is introduced into an intermediate-temperature zone.

Abstract: The description relates to production of fly ash with properties suitable for use in Portland cement. The fly ash compositions will contain coal ash, water-insoluble copper compositions and metallic mercury adsorbed onto ash particles. In one aspect, the coal ash composition will have a total mercury content of from 0.1 to 2.0 ppm and the water-soluble mercury is less than 20% of the total mercury content. The process entails combusting coal to produce hot combustion gases containing fly ash, CO2, chlorine, and mercury, cooling the combustion gases and introducing into the combustion gases at a temperature of less than 1000° F., preferably within the range of from about 250° to about 900° F., a copper-based chloride remediator (CBCR), and collecting the fly ash which comprises insoluble copper compositions and water insoluble mercury compositions.

Abstract: HCl and sulfur oxides are reduced by treating combustion gases with an aqueous copper compound referred to as copper-based chloride remediator (CBCR). The process is preferably implemented by identifying locations within a combustor for feeding the CBCR, determining the physical form and injection parameters for the CBCR and injecting the CBCR under conditions effective to reduce HCl and/or sulfur oxides. Effective temperatures for introducing the CBCRs can be from about 250° to 900° F. for HCl and up to about 2200° F. for sulfur oxides. Preferred CBCRs include copper and an ammonia moiety. One composition is copper diammonium diacetate, empirical formula of C2H7CuNO2. CBCR compositions are not sorbents and chemically convert HCl from a gaseous to a solid form.

Abstract: Disclosed is an apparatus for gasifying urea from aqueous solution, comprising: a vertically-oriented gasification chamber. A gas inlet opening permits entry of hot gases from the top and a gas outlet opening for permitting the removal of gases including gasified urea from the bottom. Sidewalls define a gasification chamber communicating with the gas inlet and gas outlet. The sidewalls include, an injector support section having a generally cylindrical side wall, at least one injector for introducing fine droplets of aqueous urea parallel to the central vertical axis, and a gas swirling device including a frame and a plurality of vanes for downwardly spiraling gases passing through it from top to bottom. Also, defined by the sidewalls are a conical midsection is provided with an outwardly expanding diameter from top to bottom, and a conical collection section with inwardly decreasing diameter from top to bottom.

Abstract: The operation of wet scrubbers, especially those based on calcium carbonate, is improved by reducing the quantities of soluble chlorides in the combustion gases fed to the scrubbers. HCl in the combustion gases is converted to a solid copper chloride and removed before the chloride reaches the scrubber. Combustion gases are treated with an aqueous copper compound referred to as copper-bearing chloride remediator (CBCR). Effective temperatures for introducing the CBCRs are preferably within the range of from about 250° to 900° F. Among the more preferred CBCRs are copper compositions including copper, an organic moiety and/or an ammonia moiety.

Abstract: The description relates to reducing hydrochloric acid in cement kilns. In one aspect, an aqueous copper-based chloride remediator is introduced into contact with combustion gases from a cement kiln. Injection is made into a defined introduction zone under conditions effective for HCl emissions control wherein the temperature is within the range of from 300° F. to 800° F., preferably from 550° F. to 750° F. The resulting d gases are discharged from the defined zone following sufficient reaction time to reduce the HCl concentration in the gases.

Abstract: Dry processes, apparatus, compositions and systems are provided for reducing emissions of sulfur oxides, and sulfur dioxide in particular, and/or HCl and/or Hg in a process employing a combination of a lime-based sorbent, in particular hydrated lime and/or dolomitic hydrated lime, and a sorbent doping agent administered to achieve coverage of a three-dimensional cross section of a passage carrying SOx and/or HCl and/or Hg-containing gases with a short but effective residence time at a temperature effective to provide significant sulfur dioxide and/or HCl and/or Hg reductions with high rates of reaction and sorbent utilization. The once-through, dry process can advantageously introduce the sorbent and sorbent doping agent dry or preferably as a slurry to enable uniform treatment. Preferred sorbent doping agents include water-soluble or water-dispersible copper and/or iron compositions which can be heated to an active form in situ by the flue gases being treated.

Abstract: Disclosed is a process for controlling injection of magnesium oxide (or precursor) for reducing the concentration of sulfur trioxide in combustion gases from a combustor burning vanadium and sulfur-containing fuel while operating the boiler with enhanced efficiency. In-fuel introduction is combined with mid-temperature introduction, where both can be operated effectively, are found to be of primary importance. When in-fuel introduction will not be effective due to selectivity problems, feed can be shifted to a high-temperature zone. Where the high- or mid-temperature zone cannot be fully utilized due to obstructions for injection or insufficient soot blowers to address fouling of that zone or boiler operational changes to integrate the magnesium oxide injection is insufficient, an entire or a portion of feed can be shifted to the low-temperature zones.

Abstract: Dry processes, apparatus, compositions and systems are provided for reducing emissions of mercury and optionally sulfur oxides and/or HCl. In an embodiment the copper-based mercury remediation composition comprises a copper ammonium complex having an empirical formula of C2H7CuNO2 or any of the other materials described, which include compositions defined by the formula Cu(NH3)x(lower carboxylate)y, wherein the lower carboxylate is selected from the group consisting of formate, acetate and propionate, x is an integer from 0 to 4, y is an integer from 0 to 2, and x+y is equal to or greater than 1. Sulfur oxides and/or HCl can be additionally reduced by introduction of dolomite hydrate sorbent, and additional mercury remediation chemicals as manganese oxides can be employed. The treated gas stream is treated with a particulate removal device.

Abstract: Disclosed are methods and apparatus for providing an ammonia feed for a low-temperature process. The process includes two defined stages, gasification and hydrolysis. In a first stage thermal reactor, an aqueous urea solution is fed to a gasification chamber and heated gases are controlled in response to demand from a low temperature process requiring ammonia. The heated gases and aqueous urea are introduced into the gasification chamber upstream to fully gasify the solution of aqueous urea to a first stage gas stream comprising ammonia and isocyanic acid. The first stage gas stream is withdrawn and maintained hot enough to prevent solids formation. All amounts of urea feed, water and heated gases fed into the first stage thermal reactor are monitored and adjusted as necessary to achieve efficient hydrolysis in the second stage hydrolysis reactor. The second stage gas stream is withdrawn from the second stage reactor responsive to demand from a low temperature process requiring ammonia.

Abstract: Disclosed are methods and apparatus for treating and analyzing a gas stream to determine the effectiveness of urea gasification. The apparatus will be capable of performing the method and will include: means for introducing an aqueous solution of urea into a reactor having hot gases therein and subjecting the aqueous to temperatures for a time to assure the gasification of the aqueous urea and form a thermal gasification product stream containing NH3 and HNCO; means for taking a sample stream from the gasification product stream; means for contacting the sample stream with a hydrolysis catalyst in the presence of sufficient water to convert HNCO to NH3 and form an ammonia sample stream; and means for analyzing the ammonia sample stream for NH3. The methods and apparatus can also be used to control a urea gasification process and/or to signal anomalous operation.

Abstract: Dry processes, apparatus, compositions and systems are provided for reducing emissions of sulfur oxides, and sulfur dioxide in particular, and/or HCl in a process employing a combination of a dolomite hydrate sorbent and a sorbent doping agent administered to achieve coverage of a three-dimensional cross section of a passage carrying SOx and/or HCl —containing gases with a short but effective residence time at a temperature effective to provide significant sulfur dioxide and/or HCl reductions with high rates of reaction and sorbent utilization. The once-through, dry process can advantageously introduce the sorbent and sorbent doping agent dry or preferably as a slurry to enable uniform treatment. Preferred sorbent doping agents include water-soluble or water-dispersible copper and/or iron compositions which can be heated to an active form in situ by the flue gases being treated.

Abstract: The description relates to improving the operation of wet scrubbers, especially those based on calcium carbonate, by reducing the quantities of soluble chlorides in the combustion gases fed to the scrubbers. By converting gaseous HCl in the combustion gases to a solid copper chloride and removing it before the chloride reaches the scrubber, the reactivity of the scrubbing slurry will be better maintained. Combustion gases are treated with an aqueous copper compound referred to as copper-bearing chloride remediator (CBCR). The process is preferably implemented by identifying locations within a combustor for feeding the CBCR, determining the physical form and injection parameters for the CBCR and injecting the CBCR under conditions effective to reduce HCl and/or sulfur oxides. Effective temperatures for introducing the CBCRs are preferably within the range of from about 250° to 900° F. Among the more preferred CBCRs are copper compositions including copper, an organic moiety and/or an ammonia moiety.

Abstract: Disclosed are methods and apparatus enabling the efficient utilization of urea for purposes such as selective catalytic reduction (SCR) of NOx, which enable feeding urea to a chamber designed to efficiently and completely gasify the urea to enable ammonia feed. Preferably, aqueous urea is fed to a gasification chamber, which is also fed with heated gases. An injector means, capable of distributing the aqueous urea as fine droplets, is positioned centrally of a gas distribution plate in the chamber. An arrangement of spaced holes in the gas distribution plate provides higher gas velocity in the vicinity of the injector means than near the walls of the chamber. Uniform gas distribution without equipment fouling is achieved.

Abstract: Disclosed are methods and apparatus for treating and analyzing a gas stream to determine the ammonia concentration. A gas stream is continuously monitored to determine the ammonia concentration by extracting gas samples from one or more locations and sending it to a tunable diode laser absorption spectroscopy instrument for analysis. By proper placement of sampling probes within a duct, depending on the particular flow patterns that have been determined by suitable modeling, e.g., computational fluid dynamics or cold flow modeling, the valves can be operated manually or by a controller to take samples at predetermined locations within the duct. This will enable taking samples from particular locations, samples representative of the entire cross section, or samples that are an average of a particular cross section. It will be possible by judicious placement of the probes and operation of the valves to map the concentrations of ammonia at a plurality of load settings and will permit continuous control.

Abstract: The description relates to improving the operation of wet scrubbers, especially those based on calcium carbonate, by reducing the quantities of soluble chlorides in the combustion gases fed to the scrubbers. By converting gaseous HCl in the combustion gases to a solid copper chloride and removing it before the chloride reaches the scrubber, the reactivity of the scrubbing slurry will be better maintained. Combustion gases are treated with an aqueous copper compound referred to as copper-bearing chloride remediator (CBCR). The process is preferably implemented by identifying locations within a combustor for feeding the CBCR, determining the physical form and injection parameters for the CBCR and injecting the CBCR under conditions effective to reduce HCl and/or sulfur oxides. Effective temperatures for introducing the CBCRs are preferably within the range of from about 250° to 900° F. Among the more preferred CBCRs are copper compositions including copper, an organic moiety and/or an ammonia moiety.

Abstract: A replacement burner system which facilitates reduction of nitrous oxide produced during combustion of a fuel. The replacement burner system comprising a fuel supply duct having an inlet and an outlet with a fuel deflector located within the fuel supply duct to facilitate redistribution of a flow of the fuel. An adjustable coal nozzle is located within the fuel supply duct between the fuel deflector and the outlet. An exterior surface of the fuel supply duct supports an air swirling device, and the air swirling device obstructs between 65% and 75% of the transverse flow area, located between an exterior surface of the fuel supply duct and the inwardly facing surface of the venturi register, after the replacement burner system is accommodated within the windbox of a combustion boiler.

Abstract: Disclosed is a system which enables the efficient utilization of urea for selective catalytic reduction (SCR) of NOx by gasifying it and feeding it to a plurality of selective catalytic reduction units associated with a plurality of gas turbines. The invention enables feeding a gasified product of the urea with the ability to fully control separate SCR units without excessive reagent usage or loss of pollution control effectiveness. Controllers determine the amount of reagent required for each turbine to control NOx emissions and then mixes the gasified urea with the correct amount of carrier gas for efficient operation of each separate SCR unit despite the demand variation between the turbines. In this manner the gasification unit can be properly controlled to provide urea on demand without the need for storing large inventories of ammonia-containing gasses to correct for fluctuations in demand.

Abstract: Disclosed are methods and apparatus for treating and analyzing a gas stream to determine the ammonia concentration. A gas stream is continuously monitored to determine the ammonia concentration by extracting gas samples from one or more locations and sending it to a tunable diode laser absorption spectroscopy instrument for analysis. By proper placement of sampling probes within a duct, depending on the particular flow patterns that have been determined by suitable modeling, e.g., computational fluid dynamics or cold flow modeling, the valves can be operated manually or by a controller to take samples at predetermined locations within the duct. This will enable taking samples from particular locations, samples representative of the entire cross section, or samples that are an average of a particular cross section. It will be possible by judicious placement of the probes and operation of the valves to map the concentrations of ammonia at a plurality of load settings and will permit continuous control.

Abstract: Dry processes, apparatus, compositions and systems are provided for reducing emissions of mercury and optionally sulfur oxides and/or HCl. In an embodiment the copper-based mercury remediation composition comprises a copper ammonium complex having an empirical formula of C2H7CuNO2 or any of the other materials described, which include compositions defined by the formula Cu(NH3)x((lower carboxylate)y, wherein the lower carboxylate is selected from the group consisting of formate, acetate and propionate, x is an integer from 0 to 4, y is an integer from 0 to 2, and x+y is equal to or greater than 1. Sulfur oxides and/or HCl can be additionally reduced by introduction of dolomite hydrate sorbent, and additional mercury remediation chemicals as manganese oxides can be employed. The treated gas stream is treated with a particulate removal device.