120results about "Flue gas purification components" patented technology

An apparatus and method for achieving increased NOx removal efficiency from an emissions control portion of a fossil fuel fired boiler while controlling ammonia slip provides excess levels of ammonia above those levels conventionally employed in SCR and / or SNCR applications. The apparatus and methods comprise, in part, use of a NOx reduction system comprising at least one selective catalytic reduction system which receives ammonia in higher amounts than conventional practice from an upstream ammonia injection point, and an ammonia reduction system positioned downstream of one or more ammonia injection points and the NOx reduction system. The excess ammonia achieves increased NOx removal, while the ammonia reduction system contains at least one ammonia destruction catalyst which permits the NOx reduction system to be operated at an increased NOx removal efficiency without a corresponding increase in ammonia slip.

An air separation unit is integrated with a power generating plant to improve the efficiency of power generation. The methods and systems improve the efficiency of power generation by utilizing liquid nitrogen from the air separation unit as the working fluid in a turbine. The liquid nitrogen is pressurized while in the liquid state. After warming the pressurized nitrogen stream by cooling the air for the air separator unit, the compressed nitrogen is expanded in a turbine to perform work. After expansion, the nitrogen is vented to ambient air. The nitrogen in its pressurized state can be used for energy storage and / or for smoothing out power demand on a power grid.

The present invention provides improved boiler assemblies (10) with enhanced pollution abatement properties through injection and recycling of particulate sorbent materials including sodium bicarbonate, trona, and mixtures thereof. The assemblies (10) include a boiler (12), economizer (14), air heater (15), and recirculation reactor (16). Fresh sorbent material is introduced via assembly (60) into the boiler assembly (10) at one or more injection locations, and serves to sorb NOx, SOx, and other pollutants in the flue gas. The flue gas and entrained sorbent material then pass through reactor (16) for separation of sorbent, which is then recycled for injection back into the assembly (10) upstream of reactor (16).The present invention can also be used in industrial applications where the same emissions are generated and are needed to be controlled. Examples of such applications are Cement and Lime Kilns.

A system and method of maintaining an optimal temperature range for a catalyst section in a HRSG comprising placing a portion of the exhaust stream in a heat exchanger and superheater, diverting a second portion around the heat exchanger and superheater, combining the two portions and contacting the two portions with a catalyst section. Alternatively, a system of heat exchangers are employed to address the fluctuating exhaust temperature caused by the intermittent use of the duct burners.

The present invention is a method for reducing the slagging and fouling of the surfaces of the waterwalls, firebox, superheater, and reheater of the furnace of a coal-fired steam boiler. The process reduces the firebox exit temperature to below the specific ash melting temperature by injecting the following, either alone or in combination, into ports located in the upper section of the firebox: recirculated flue gas from downstream of the electrostatic precipitator, atomized water, or a sorbent water slurry. All of these materials have a lower temperature than the main flue gas or require additional heat for evaporation. Mixing these materials with the main flue gas from the furnace will not affect the coal combustion process, yet will reduce the temperature of any fly ash particles in the main flue gas to below the specific ash fusion temperature, and thus, prevent slagging and fouling within the furnace.

The present invention provides improved boiler assemblies (10) with enhanced pollution abatement properties through injection and recycling of particulate sorbent materials including sodium bicarbonate, trona, and mixtures thereof. The assemblies (10) include a boiler (12), economizer (14), air heater (15), and recirculation reactor (16). Fresh sorbent material is introduced via assembly (60) into the boiler assembly (10) at one or more injection locations, and serves to sorb NOx, SOx, and other pollutants in the flue gas. The flue gas and entrained sorbent material then pass through reactor (16) for separation of sorbent, which is then recycled for injection back into the assembly (10) upstream of reactor (16). In another aspect, the invention provides pollution abatement apparatus (110) and methods employing an upstream recirculation reactor (114), a supply of fresh sorbent (118), and a downstream collector (116). In the reactor (114), fresh sorbent reacts with incoming hot flue gas (112) to generate a reduced pollutant flue gas (128) and a solids fraction including reacted sorbent and pollutants, and unreacted sorbent. Recirculation apparatus (120) provided between the reactor outlet (126) and reactor (114) serves to generate a substantially constant mass or volume flow rate of the reactor solids fraction, which minimizes the use of fresh sorbent and maximizes the pollution abatement efficiency of the apparatus (110).

A method for improving effectiveness of a steam generator system includes providing air to an air preheater in excess of that required for combustion of fuel and providing the air at a mass flow such that the air preheater has a cold end metal temperature that is no less than a water dew point temperature in the air preheater and such that the cold end metal temperature is less than a sulfuric acid dew point temperature. The method includes mitigating SO3 in the flue gas which is discharged directly from the air preheater to a particulate removal system and then directly into a flue gas desulfurization system. Flue gas reheat air is fed from the air preheater to heat the flue gas prior to entering a discharge stack to raise the temperature of the flue gas to mitigate visible plume exiting and to mitigate corrosion in the discharge stack.

An air separation unit is integrated with a power generating plant to improve the efficiency of power generation. The methods and systems improve the efficiency of power generation by utilizing liquid nitrogen from the air separation unit as the working fluid in a turbine. The liquid nitrogen is pressurized while in the liquid state. After warming the pressurized nitrogen stream by cooling the air for the air separator unit, the compressed nitrogen is expanded in a turbine to perform work. After expansion, the nitrogen is vented to ambient air. The nitrogen in its pressurized state can be used for energy storage and / or for smoothing out power demand on a power grid.

A plant for generation of steam for oil sand recovery from carbonaceous fuel with capture of CO2 from the exhaust gas, comprising heat coils (105, 105′, 105″) arranged in a combustion chamber (101) to cool the combustion gases in the combustion chamber to produce steam and superheated steam in the heat coils, steam withdrawal lines (133, 136, 145) for withdrawing steam from the heat coils, an exhaust gas line (106) for withdrawal of exhaust gas from the combustion chamber (101), where the combustion chamber operates at a pressure of 5 to 15 bara, and one or more heat exchanger(s) (107, 108) are provided for cooling of the combustion gas in line (106), a contact device (113) where the cooled combustion gas is brought in countercurrent flow with a lean CO2 absorbent to give a rich absorbent and a CO2 depleted flue gas, withdrawal lines (114, 115) for withdrawal of rich absorbent and CO2 depleted flue gas, respectively, from the contact device, the line (115) for withdrawal of CO2 depleted flue gas being connected to the heat exchangers (107, 108) for heating of the CO2 depleted flue gas, and where the rich absorbent is regenerated an absorbent regenerator (116), the regenerated lean absorbent is recycled to the absorber (113), and a gas withdrawal line (121) connected to the absorber for withdrawal of CO2 and steam from the regenerator (116), is described.