The Babcock & Wilcox Company

Mcdermott Technology, Inc.

Babcock & Wilcox Power Generation Group, Inc.

Other

Electric Power Research Institute Incorporated

William Downs

Ralph T Bailey

John B Doyle

Stanley J Vecci

Paul S Nolan

Paul Chu

Peter V Smith

Dennis W Johnson

Paul J Williams

Bryan J Jankura

Edward D Daum

John M McCoury, Jr

Robert B Myers

Dennis K McDonald

Kevin J Rogers

Douglas J DeVault

Daniel R Rowley

Robert A McIlroy

Larry A Hiner

John M Rackley

Karl H Schulze

Gerald T Amrhein

Edward A Pirsh

Stephen S Strom

William C Kish

Paul L Cioffi

James J Warchol

Hamid Farzan

Christopher L Verrill

Alan J Kubasco

William E Newkirk

Xiaoyu Guo

Jack F Stewart

Ed A Pirsh

Seyed B Ghorishi

George H Hay

Steve C Datsko

Peter VanSmith

Jean Czuczwa

Dennis K Mcdonald

Douglas J Devault

The present invention relates generally to the field of emission control equipment for boilers, heaters, kilns, or other flue gas-, or combustion gas-, generating devices (e.g., those located at power plants, processing plants) and, in particular to a new and useful method and apparatus designed to improve the water supplied to non-calcium-based, aqueous wet SOscrubbers. In another embodiment, the present invention relates to a system and method for softening water for use in non-calcium-based, aqueous wet SOscrubbers.

System and method for softening water for use in a scrubber

An apparatus and method for achieving increased NOremoval 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 NOreduction 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 NOreduction system. The excess ammonia achieves increased NOremoval, while the ammonia reduction system contains at least one ammonia destruction catalyst which permits the NOreduction system to be operated at an increased NOremoval efficiency without a corresponding increase in ammonia slip.

Enhancement of conventional SCR and SNCR processes with ammonia destruction catalyst

An apparatus for low-temperature NO-reduction is disclosed, which is useful in boiler installations used at electric-generating plants. The apparatus employs one or a plurality of moving-bed reactors wherein a moving bed of common base-metal catalyst is used for selective catalytic reduction of NOpresent in flue gas. The moving bed permits continuous introduction of fresh or regenerated catalyst, thus obviating the conventional problems of sulfur-poisoning and consequent reduction in catalytic activity with such catalysts. Due to the lower activation energies of such catalysts, an SCR utilizing the moving-bed reactors disclosed herein can be located downstream of the air heater, further improving electric-generating efficiency. Methods for low-temperature NOreduction are also disclosed.

[object Object]

The present invention is related to a system for removal of moisture and contaminants from recirculated flue gas. The system includes a spray tower for spraying the flue gas with a liquid reagent to remove contaminants from the flue gas. A heat exchanger, integrally connected to the spray tower, cools the liquid reagent before the reagent is sprayed onto the flue gas stream. Cooled liquid reagent improves the condensation of the water vapor in the flue gas during the spraying process and provides a lower moisture content flue gas exiting the system. Combustion process efficiency improves as flue gas redirected to the burner for combustion contains.

Process for controlling the moisture concentration of a combustion flue gas

A method and apparatus for reducing and removing mercury in industrial gases, such as a flue gas, produced by the combustion of fossil fuels, such as coal, adds sulfide ions to the flue gas as it passes through a scrubber. Ideally, the source of these sulfide ions may include at least one of: sulfidic waste water, kraft caustic liquor, kraft carbonate liquor, potassium sulfide, sodium sulfide, and thioacetamide. The sulfide ion source is introduced into the scrubbing liquor as an aqueous sulfide species. The scrubber may be either a wet or dry scrubber for flue gas desulfurization systems.

Use of sulfide-containing liquors for removing mercury from flue gases

Chlorine and sulfide species are separately introduced to a flue gas passing through a scrubber in order to remove the elemental and oxidized mercury from the gas through the precipitation of mercuric sulfide at near 100% efficiency.

Method for controlling elemental mercury emissions

An apparatus and method for sulfur recovery uses a scrubber tower with a plurality of vertically spaced scrubber trays in the tower. Sulfide-lean liquor is supplied to each of the trays and an acid gas is supplied to the tower below the trays. A downcomer extends in the tower and through the trays for accumulating liquid from the trays and moving the liquid to the bottom of the tower. The sulfide-lean liquor and acid gas are selected to form a sulfite-rich or sulfide-rich liquor in each of the trays which are brought to the bottom of the tower through the downcomer for removal from the tower.

Apparatus to recover sulfur from concentrated acid gas into alkaline solution

A method and apparatus for reducing mercury in industrial gases such as the flue gas produced by the combustion of fossil fuels such as coal adds hydrogen sulfide to the flue gas in or just before a scrubber of the industrial process which contains the wet scrubber. The method and apparatus of the present invention is applicable to installations employing either wet or dry scrubber flue gas desulfurization systems. The present invention uses kraft green liquor as a source for hydrogen sulfide and/or the injection of mineral acids into the green liquor to release vaporous hydrogen sulfide in order to form mercury sulfide solids.

Apparatus for control of mercury

A method and apparatus for ultra-high particulate collection of sub-micron aerosols in a fuel gas conveys the fuel gas to a first venturi scrubber for removing a relatively large amount of particulates and leaving a smaller particulate load which is not removable in the first venturi scrubber. The fuel gas with the smaller particulate load is then conveyed to an electrostatic agglomerator for agglomerating the remaining smaller particles in the smaller particle load into larger particles. The fuel gas with the agglomerated larger particles is then conveyed to a second venturi scrubber for removing the agglomerated larger particles.

Ultra-high particulate collection of sub-micron aerosols

An integrated flue gas treatment and condensing heat exchanger is used to scrub sulfur dioxide from the flue gas produced by a power boiler used in a paper mill operating a kraft process. Sensible and latent heat from the flue gas is recovered and the condensate effluent from the condensing heat exchanger contains valuable chemicals that are returned to and used in the kraft process.

Waste recovery and utilization in the kraft recovery process

A method for controlling emissions of a fossil fuel fired boiler including a high temperature fabric filter house with an SCR catalyst situated therein for receiving flue gases along with an injected ammoniacal compound and sorbent. The sorbent reacts with the SO.sub.x while the ammoniacal compound reduces the NO.sub.x in the presence of the SCR catalyst inside the high temperature fabric filter house. Both the SO.sub.x and the particulates are removed upstream of the SCR catalyst to diminish the problems of SO.sub.2 or SO.sub.3 poisoning of the catalyst and erosion and fouling of the catalyst with the fly ash. Since the sulfur oxides and particulates are removed prior to the heat recovery system, the fouling and corrosion potential are substantially decreased thus allowing the heat recovery system to be operated at a lower outlet flue gas temperature which yields an incremental improvement in energy recovery.

SO.sub.x, NO.sub.x and particulate removal system

A method and apparatus for controlling emissions of a fossil fuel fired boiler including a high temperature fabric filter house with an SCR catalyst situated therein for receiving flue gases along with an injected ammoniacal compound and sorbent. The sorbent reacts with the SO.sub.x while the ammoniacal compound reduces the NO.sub.x in the presence of the SCR catalyst inside the high temperature fabric filter house. Both the SO.sub.x and the particulates are removed upstream of the SCR catalyst to diminish the problems of SO.sub.2 or SO.sub.3 poisoning of the catalyst and erosion and fouling of the catalyst with the fly ash. Since the sulfur oxides and particulates are removed prior to the heat recovery system, the fouling and corrosion potential are substantially decreased thus allowing the heat recovery system to be operated at a lower outlet flue gas temperature which yields an incremental improvement in energy recovery.

SO.sub.x , NO.sub.x , and particulate removal system

Improved SO.sub.x, NO.sub.x, and particulate removal system

Growing community of inventors

Alliance, OH, United States of America

William Downs