FGD & DeNOx Abstracts

December 2007

The following four papers were presented at Coal-Gen 2007, Milwaukee, WI, August 2007.

HH 07 12 01 “Comparison of Wet and Dry FGD Technologies for Use with Low- and Medium-Sulfur Coals” by William Siegfriedt and Rajendra Gaikwad, Sargent & Lundy, Chicago, IL. 16 p.
The popular FGD technologies have evolved over the past 30 years. Common perceptions about relative costs of the various technologies are based largely on information that applied to the technologies when they were in their infancy. This study takes a fresh look at the relative costs when applied to popular low- and medium-sulfur coals. The costs are examined at the popular 500 MW size; however, some of the technologies experience significant cost thresholds at 400 MW, so this size has also been considered. This paper presents the results of a study conducted by Sargent & Lundy for the National Lime Association (NLA). A detailed report is available from NLA.
IH 401 SO₂ REMOVAL, IH 212 LIMESTONE-GYPSUM,
IH 801 COSTS, IH 650 COAL, IH 300 DRY SCRUBBING,
C NATIONAL LIME ASSOCIATION

HH 07 12 02 “Operating Challenges and Experience with PRB Coal at We Energies Pleasant Prairie Units 1 and 2” by Mike Wiesneth, We Energies, and Clayton A. Erickson, Kellie Bresnahan and Rod Beittel, Riley Power Inc. 12 p.
We Energies teamed with Riley Power Inc., a Babcock Power Inc. company, in an alliance to develop a plan to retrofit the Pleasant Prairie Power Plant (P4) Unit 2 with an SCR as part of their NO_X compliance strategy. A key evaluation consideration was the application of a high dust SCR configuration to a PRB coal-fired boiler. We Energies made the commitment to install a high dust SCR with very limited experience with PRB coals to meet required emission limits. In addition We Energies ultimately selected aqueous ammonia as the reagent for the SCR system. The use of PRB coal is critical to We Energies generation economics. In order to insure a good design base an SCR pilot plant test program was undertaken with Riley Power. This paper will describe the long term operating experience with Unit 2 including catalyst performance, ammonia injection, removal efficiency and maintenance procedures. Based on Unit 2 performance the final design for Unit 1 was revisited with minor design changes that will be discussed.
IH 641 UTILITY BOILERS, IH 816 RETROFIT, IH 410 SCR, IH 400 NO_X REMOVAL,
IH 656 COAL, POWDER RIVER BASIN, C WE ENERGIES, C RILEY

HH 07 12 03 “Scrubber Efficiency Improvements through Advanced Spray Technology” by Robert Van Durme and Colin Sauer, Lechler, Inc., St. Charles, IL. 5 p.
Spray towers are a proven technology, with many years of operating experience. As regulations continue to tighten, power plants are looking for opportunities to increase the scrubber removal rate or use a higher sulfur coal while maintaining saleable gypsum. Often overlooked is the importance of droplet surface area on scrubber efficiency. New spray technology is allowing for smaller droplet sizes and improved liquid-to-gas contact that is improving scrubber performance. In many instances, efficiency can be gained by replacing old nozzles with technologically better nozzles, which maximize droplet surface area and enhance SO₂ removal. Properly designed header systems and well-engineered nozzles can increase these shear forces, increasing overall scrubber efficiency. Some known design techniques in use today include offset headers and differing spray angles to maximize slurry coverage to minimize gas sneakage and loss of slurry at the wall.
IH 523 NOZZLES, IH 844 EFFICIENCY, IH 201 SPRAY TOWER

HH 07 12 04 “Wet FGD System Retrofit Unloading of Limestone for a Midwest Utility and the Supply of a Metso IRI Equilibrium Crane” by Richard P. Fedosick, Dennis K. Manley and W. Dwaine McClean, Metso Bulk Material Handling. 10 p.
A large public utility generating station, located in the Midwest region of the USA retrofitted two 525 MW Units with flue gas desulfurization (FGD) systems. The purpose of the FGD systems is to remove 97% of SO₂ from existing flue gas. Limestone aggregate stones, measuring < 3/4 in. each, are utilized as a raw material in the production of limestone slurry for the process. The stone is delivered to the site by river barge. Each barge measuring 35’W x 195’ x 12’D contains approximately 1600 tons of limestone. The system design requires that a maximum of 569,400 tons of limestone be unloaded from the barges each year. The challenge was to design the crane to accommodate all river level fluctuations while loading limestone into the hopper, 90 feet away, and maintaining the appropriate speed required to achieve the specified peak unloading rate.
C METSO, IH 530 MATERIAL HANDLING,
IH 641 UTILITY BOILERS, IH 528 REAGENTS LIMESTONE,
IH 816 RETROFIT

The following eight papers were presented at The 2nd China International deSOx deNOx Exhibition & Conference, Beijing, China, September 2006.

HH 07 12 05 “Future FGD and DeNox Developments in China and Other Countries” by Robert McIlvaine, McIlvaine Company, and Hann S. Huang, ANL. 8 p.
China is undertaking a massive program to install FGD systems on new coal-fired boilers and to retrofit existing boilers as well. At the same time the U.S. is also undertaking a big FGD program. A number of new FGD systems are also under design in other parts of the world. Unless proper planning is undertaken there will be a shortage of critical components and engineering personnel. It will be very desirable for Chinese utilities to take advantage of all the experience gained regarding FGD in other countries. Most systems now being installed in China are partnerships between Chinese and offshore partners. The decision making process regarding FGD should be organized in a tree with three branches, Informational, Physical and Procedural.
W 013 CHINA, IH 801 COSTS, IH 400 NO_X REMOVAL, IH 130 MARKETS,
IH 410 SCR, IH 453 COAL-FIRED BOILERS

HH 07 12 06 “Investigations on Aluminum-Induced Limestone Blinding at Wet FGD Plants Producing Gypsum” by H. Gutberlet, G. M. Böhm and S. Neuhaus, E.ON Engineering GmbH, Gelsenkirchen, Germany and M. Dickamp, M. Kraus and C. Moser, Lentjes GmbH, Ratingen, Germany. 12 p.
Due to the increasing use of imported coals with varying characteristics, having potentially negative effects on ESP performance, limestone blinding has been observed again at many sites in Europe. It is also a current problem in China, where numerous FGD plants have been retrofitted to existing power plants operating ESPs at lower efficiencies. Based on previous publications on this subject, recent investigations were carried out to get a more thorough understanding of the mechanisms responsible for the A1F_x-blinding of the limestone in order to better define and implement necessary remedial measures. The investigations comprised tests at operating FGD plants as well as various laboratory tests.
IH 580 ESPS, IH 215 FORCED OXIDATION, IH 212 LIMESTONE—GYPSUM,
IH 528 REAGENTS—LIMESTONE

HH 07 12 07 “Gas Cleaning System for Sinter Plant” by Zhenyang LI and Zhijun Han, ALSTOM China, Beijing, China and Gianfranco Velcich, ALSTOM Italy, Milan, Italy. 7 p.
Dry flue gas cleaning and dioxin control systems have been installed by ALSTOM at the Sollac Fos sur Mer plant, a 572 m2 sintering unit. The emission control system was commissioned in 2005, and has been at full load operation since then, meeting all emission and contractual guarantees. This paper discusses how ALSTOM’s know-how of dry flue gas desulfurization system was applied to the sintering flue gas, the design features of the emission control system at Sollac Fos, operation experiences, as well as lessons learned during the project execution and initial operation.
IH 159 HEAVY METALS, IH 184 INNOVATIVE FGD, IH 401 SO₂ REMOVAL,
IH 300 DRY SCRUBBING, C ALSTOM

HH 07 12 08 “Optimization of the Selective Catalytic Reduction System” by Mou Jian and Fred Kozak, ALSTOM Inc. Knoxville, TN. 7 p.
This paper addresses the important parameters that influences the SCR system performance and lifetime cost, such as catalyst layer arrangement in the reactor (2+1, 2+2, 3+1, etc.), aerodynamic design of the flue gas duct, capital cost vs operation cost, catalyst management, etc. Statistical analysis technologies are used to analyze design data from a large pool of reference plants.
IH 410 SCR, IH 400 NO_X REMOVAL, IH 801 COSTS,
IH 421 CATALYSTS, C ALSTOM

HH 07 12 09 “Pure Polyurea —– The Coating of Choice for China’s Power Industry” by S. Christopher Bean, Nukote Coating Systems International, LLC. 7 p.
With the dramatic advances of the coating industry, these polyureas, more than any other polymer coating, stand out in their versatility, strength and longevity. This article explains the reasons why pure polyurea is the best choice of the coating system in the Power Industry.
W 013 CHINA, IH 507 COATINGS

HH 07 12 10 “Spray Drying Absorption, the Economic Solution for Flue Gas Desulphurisation” by Niels Jacobsen and Bjarne Rasmussen, Niro A/S Soeborg, Denmark, Mark Lux, Black Hills Power & Light, Gillette, Wyoming and Ludek Sklenar, Chemopetrol, a.s., Litvinov, Czech Republic. 7 p.
This paper presents a description of the Niro Spray Drying Absorption process and the key features that characterize the process, a process now selected at power plants worldwide with a corresponding capacity of 17,000 MW_e. Two applications will be presented, a European, where the combined flue gas from eight small boilers is treated in two parallel spray dryer absorbers and an American, where the Niro Spray Drying Absorption process has successfully been installed adjacent to a competing technology. Operating experience from the large number of plants now equipped with the Spray Drying Absorption process demonstrate that this process is well proven and is ideal for many Chinese power plants.
W 092 EUROPE, W 013 CHINA, IH 330 SPRAY DRYER, IH 801 COSTS, C NIRO

HH 07 12 11 “TMT 15 — A Safe Handling, Non-Toxic/Non-Hazardous, Environmentally Friendly Compound for Separating Heavy Metals from Coal Fired Power Stations’/Incinerators’ Effluents” by Jerry Chung, Degussa. 1 p.
TMT 15 is a kind of heavy metal treatment agent. Its molecular formula is (C₃N₃Na₃S₃). Chemical name is trimercapto-s-triazine or trisodium salt and is produced in Germany. TMT 15 can remove more than 99% heavy metals from wastewater and heavy metal residuals after treatment are far below 0.5 mg/l. TMT 15 also produces good results when hydroxide precipitation exhibits little or no effect. In fact, TMT 15 has been used for wastewater treatments in coal-fired power stations, incineration plants, plating and surface finishing plants for many years.
IH 453 COAL-FIRED BOILERS, IH 159 HEAVY METALS, IH 180 HEALTH EFFECTS

HH 07 12 12 “Challenges of a Proper SCR Design — Fisia Babcock Technologies and Experiences” by Wolfgang Schuettenhelm, Fisia Babcock Environment GmbH, Gummersbach, Germany. 8 p.
This paper will focus on the importance of all the design factors being necessary to achieve a very reliable and highly available operation of the SCR while considering Chinese high ash coals. FBE’s very sophisticated ammonia mixing and SCR reactor inlet distribution systems supported by modeling are optimal means to ensure the necessary flow distributions upstream of a catalyst which targets its operational performance. The effectiveness of the FBE technology is illustrated by means of SCR retrofit examples of very recent reference installations in Europe enabling NO_X removal efficiencies in the range of 90%.
W 013 CHINA, W 092 EUROPE, IH 260 AMMONIA SCRUBBING, IH 410 SCR,
IH 816 RETROFIT, IH 844 EFFICIENCY,
IH 400 NO_X REMOVAL, IH 815 PLANT DESIGN,
IH 190 MODEL FLOW STUDIES, C FISIA BABCOCK ENVIRONMENTAL

HH 07 12 13 “Design of the FLOWPAC WFGD System for the Amager Power Plant” by Mati Maripuu, ALSTOM Power Sweden AB, Văxjö, Sweden, Ray Gansley, ALSTOM, Knoxville, TN, René Erik Olesen, Vattenfall A/S, Copenhagen, Denmark and Mario Crespi, ALSTOM Power Italia S.p.A., Milano, Italy. Presented at Power-Gen, Orlando, FL, November 2006, 12 p.
ALSTOM has been awarded a contract by Vattenfall A/S to supply its innovative wet flue gas desulfurization (WFGD) technology, FLOWPAC, and a Selective Catalytic Reduction (SCR) system to the Amager heat and Power Plant, close to the Danish capital of Copenhagen. This paper focuses on the FLOWPAC WFGD system that will be installed to remove sulfur oxide emissions from the new CHP coal-fired boiler that is also designed to burn fuel oil and straw. The unit has a firing capacity of 350 MJ/s. ALSTOM’s new generation WFGD absorber, FLOWPAC, has few moving parts (no agitators or pumps) and utilizes a cross-flow tray design for optimal SO₂ mass transfer. It is targeted for applications combusting fuels with a medium to high sulfur content that require excellent SO₂ removal efficiency and good SO₃ removal efficiency, as well as applications with varying fuels that will take advantage of the superior controllability.
W 018 DENMARK, IH 815 PLANT DESIGN, C ALSTOM,
IH 184 INNOVATIVE FGD, IH 453 COAL-FIRED BOILER,
IH 401 SO₂ REMOVAL, IH 641 ORIMULSION

HH 07 12 14 “FLOWPAC for the Elektrénai Power Plant — A Novel FGD Absorber Principle” by Bo Herrlander, Alstom Power Sweden AB, Sweden. Presented at Power-Gen 2007, Madrid, Spain, June 2007, 13 p.
The Elektrénai Power Plant will be retrofitted with wet flue gas desulphurization and particulate removal on nine boilers producing steam for generation of totally 1350 MW electric power. Two boilers will in principle be connected to one absorber. Thus there will be four 300 MW size FLOWPAC absorbers and one 150 MW. The FLOWPAC absorber will take flue gas with up to 2500 ppm SO₂ and is designed for a removal efficiency of 98%. This high sulfur dioxide concentration comes from firing Orimulsion. The alternative fuels are heavy fuel oil (3, 5% S) and natural gas. The units will come into operation starting late 2007 with the last unit on stream late 2009. Alstom’s new generation WFGD absorber, FLOWPAC, has few moving parts and utilizes a cross-flow tray design for optimal SO₂ mass transfer. This means the absorber operates without agitators or pumps. The absorption of SO₂ takes place when flue gas is intimately mixed with lime slurry in a turbulent bed. The absorption efficiency is easily and precisely controlled through the bed height, giving full freedom for the boiler operator to fire fuel with varying sulfur content.
W 189 LITHUANIA, C ALSTOM, IH 642 ORIMULSION,
IH 401 SO₂ REMOVAL, IH 847 PARTICULATE SCRUBBING

HH 07 12 15 “Green River Unit #3 Low NO_X Control Integration” by George Keller, Burns and Roe, Oradell, NJ, and Bryan Baker and Russell J. Jones, Green River Station, Kentucky Utilities, Central City, KY. Presented at Coal-Gen 2006, Cincinnati, OH, August 2006, 6 p.
Green River Station is conducting a Study/Boiler Control Betterment Project with the purpose of developing an integrated combustion control strategy. The strategy will incorporate requirements for consistent low NO_x performance into the total air flow/boiler control. The intent is to perform an integrated tuning of the redesigned boiler control and low NO_X burners to minimize NO_X charges per MWhr and improve heat rate. This paper will report the results of the Boiler Control Betterment Project and subsequent tuning efforts.
IH 453 COAL-FIRED BOILERS, IH 460 LOW NO_X BURNERS,IH 469 COMBUSTION CONTROL

HH 07 12 16 “Successful Implementation of Canada’s First Coal-Fired Post-Combustion NO_X Reduction Systems” by Jonathan D. Fleming and Gary R. Westerveld, Babcock & Wilcox Canada, Cambridge, Ontario, Canada and David S. Johnston, Ontario Power Generation, Nanticoke Thermal Generating Station, Canada. Presented at Coal-Gen 2006, Cincinnati, OH, August 2006, 7 p.
This paper describes the successful design, installation and operation of Canada’s first Selective Catalytic Reduction (SCR) systems for nitrogen oxides (NO_X) reduction installed at Ontario Power Generation’s (OPG’s) Lambton and Nanticoke coal-fired power stations. OPG’s initiative to reduce the emissions of NO_X (which contribute to the formation of smog) from their coal-fired stations led to the award of a contract to Babcock & Wilcox Canada (BWC) in June 2001 for the turnkey supply of SCRs for Lambton units 3 and 4 and Nanticoke units 7 and 8. B&W’s scope included design, supply, construction and start-up of the SCRs, anhydrous ammonia systems, SCR support steel, pressure part modifications, platework modifications and reinforcement, control components and induced draft (ID) fan upgrades. All units have completed acceptance tests and are in commercial operation.
W 010 CANADA, IH 400 NO_X REMOVAL, IH 410 SCR,
IH 453 COAL-FIRED BOILERS, IH 641 UTILITY BOILERS