HIGH-DUST SCR DESIGN TO LIMIT IMPACT OF HIGH SULFUR OPERATION ON AIR PREHEATER OPERATION Volker Rummenhohl, Tackticks, LLC 2300 Englert Avenue, Suite C,

Slides:



Advertisements
Similar presentations
Operational Ideas for Supercritical Systems The Ultimate Criteria for Appreciation ….. P M V Subbarao Professor Mechanical Engineering Department I I.
Advertisements

Control calculations Heat Engines & Boilers.
Lecture Notes - Energy Conservation Topic “Boiler”
Energy Efficient Steam Systems
ELECTROSTATIC PRECIPITATORS
MEASURES TO REDUCE NO x EMISSIONS M. Sc. Engineering Policy and Technology ManagementEnergy Management and Policy Por: Miguel Leocádio João Meyer MEASURES.
In India 65% of total power is generated by the Thermal Power Stations. Main parts of the plant are 1. CHP.
Convection in Flat Plate Turbulent Boundary Layers P M V Subbarao Associate Professor Mechanical Engineering Department IIT Delhi An Extra Effect For.
Design Steps : Furnace Of A Steam Generator P M V Subbarao Professor Mechanical Engineering Department Selection of Geometric Parameters….
Sara Jones 24NOV08. Background  In most conventional combustion processes, air is used as the source of oxygen  Nitrogen is not necessary for combustion.
© 2011 Hamworthy Combustion IED RELATING TO OIL AND GAS BURNERS FOR INDUSTRIAL USE Nigel Webley Group Technical Director Hamworthy Combustion Tel:
NOx Sources and Control Methods CE/AE 524B Air Pollution J. (Hans) van Leeuwen.
Fuel Additive Training. Cost Factor in Oil Fired Plant.
TMTS NOx CONTROL for STATIONARY SOURCES Copyright TMTS Associates, Inc. and J.J. Santoleri, 2001, all rights reserved.
NOx Control.
Control of Sulfur Oxides Dr. Wesam Al Madhoun
PM fine Quantification Ron Myers OAQPS/SPPD/MPG 1/30/2013 Perceptions about Ammonia Slip, Acid Gases, Condensable Particulate Matter and Applicable Test.
Bachelor Degree in Maritime Operations (BMO)
Previous MACT Sub Categories EPA has recognized differences in other industry rules by using sub-categorization: – Differences in processes – Differences.
FGD, SCR, & Other Retrofit NOx Controls FGD, SCR, & Other Retrofit NOx Controls Presented by: Joe Ennis, Director Project Engineering APP Site Visit October.
Bereichskennung oder Produktname Process Instrumentation and Analytics Januar, 2003 Folie 1 A&D PI2 SE1 Siemens Process Analytics in the Cement Industry.
Generation and Control of Vacuum in Furnace
Control of Nitrogen Oxides Dr. Wesam Al Madhoun. Specific sources of NO x Combustion sources Automobiles Boilers Incinerators High-temperature industrial.
Performance and Benefits of Flue Gas Treatment Using Thiosorbic Lime
Capture of Heat Energy From Diesel Engine After Cooler Circuit (2006 Annual Report) Mark Teitzel Alaska Village Energy Corporation
Coal Burning System.
Boiler efficiency Heat Engines & Boilers.
Heat exchangers The device at which heat exchange between two fluids at different temperatures and separated by a solid wall occurs is called heat exchanger.
Steam Power Station Presented By Ashvin G. Patel Asst. Prof. (E.E.)
Air Pollution Control – Design Considerations: General Objectives: Background for equipment design To be conversant with equipment manufacturers Understand.
ISAT Module V: Industrial Systems
SUSTAINABLE ENERGY REGULATION AND POLICY-MAKING FOR AFRICA Module 13 Energy Efficiency Module 13: SUPPLY-SIDE MANAGEMENT.
Lecture Objectives: Finish boilers and furnaces Start with thermal storage systems.
Heat Exchanger & Classification Prepared by: Nimesh Gajjar
BOILER PLANT OPERATION Presented By Mr. Sivanand Ray
Lecture Objectives: Continue with power generation Learn basics about boilers and furnaces.
Technical Seminar Presented by :- Dipti Ranjan Khuntia (EE ) ELECTROSTATIC PRECIPITATORS Presented by Dipti Ranjan Khuntia Roll # EE
“Enhanced Plant Performance via Effective SO 3 Control” Sterling Gray, URS Corporation Mick Harpenau, Duke Energy EUEC Conference Phoenix, AZ February.
CLIMATE AND TOPOGRAPHY Temperature Inversions Temperature inversions occur when a stable layer of warm air overlays cooler air, reversing the normal temperature.
Objectives -Discuss Final Project -
Power Plant Construction and QA/QC Section 9.2 – Air Emission Controls Engineering Technology Division.
CFD Modeling for Design of NOx Reduction in Utility Boilers Seventeenth Annual ACERC Conference Salt Lake City, UT February 20-21, 2003 S. Vierstra J.J.
Generating Stations. Bulk electric power is produced by special plants known as generating stations or power plants. Depending upon the form of energy.
Welcome PRESENTATION BY ASHISH MISHRA.
Illinois Basin Coal Issues AEP BRO Forum /30/2013 By Pat Malone.
ENERGY EFFICIENCY IN THERMAL UTILITIES AND SYSTEM
A Seminar On Suratgarh Super Thermal Power Station (Raj.)
Scrubbers Colloquium N. Maximova and the class. Puu
Thermal Power Station.
THERMAL POWER PLANT.
FOOD ENGINEERING DESIGN AND ECONOMICS
STEAG SCR-Tech, Inc. located in Charlotte, Grover and Kings Mountain
ATMOSPHERE PROTECTION TECHNOLOGY April 22nd, 2013.
AAPCA 2016 Spring Meeting Panel: NOx Controls Updates
Coal quality issues and options Dr Andrew Minchener OBE General Manager IEA Clean Coal Centre January 2015.
Conversion of a coal-fired power boiler: Green electricity through biomass combustion. Experience from EC Białystok S.A. Finnish-Polish energy seminar.
Concentric Tube (double-pipe) Heat Exchangers
REDUCTION OF NOx & SOx EMISSION WITH ALTERNATIVE FUEL UTILIZATION IN CEMENT INDUSTRY SOx NOx.
Humidity Measurement Benefits in Power Applications
PTRT 1391 Natural Gas Processing II Chapter 3
Unit 42: Heat Transfer and Combustion
Fans & Heaters technical seminar
Concentric Tube (double-pipe) Heat Exchangers
Definition of Corrosion
DJR 3000 S1 Emulsion Stabilizer CUSTOMER OBJECTIVES: Provide quality products that help protect the environment Stress service to the customer.
Miroslav Variny, Otto Mierka
Heat Exchangers Heat Exchangers.
Rajan Bhandari Senior Lecturer
Anatomy & Organs of Power Plant Steam Generators
Presentation transcript:

HIGH-DUST SCR DESIGN TO LIMIT IMPACT OF HIGH SULFUR OPERATION ON AIR PREHEATER OPERATION Volker Rummenhohl, Tackticks, LLC 2300 Englert Avenue, Suite C, Durham, NC Tel: 919/ ; FAX: 919/ ; William Ellison, Ellison Consultants 4966 Tall Oaks Drive, Monrovia, Maryland Tel: 301/ ; FAX: 301/ ; Helmut Weiler, Weiler Consultants Hofer Heide 31, D42549 Velbert, Germany Tel: 011/49/ ; Fax: 011/49/ ; U.S. DOE/NETL 2006 ENV. CONTS. CONF. SCR AND SNCR FOR NO X CONT. PITTSBURGH, PA, MAY 17, 2006

2 If A Unit Has Significant, Air-Preheater- Related, SO 3 Problems, SCR Retrofitting Can Be Expected To Make The Situation Worse. If an Uncontrolled Unit Does Not Have Significant SO 3 Problems, Adequate SCR Retrofit System Design and Operation Should Not Lead To Increased Problems in Boiler System Performance or Maintenance.

3 INDICATION OF POTENTIAL PROBLEMS ABSENT SCR (AND ITS CATALYTIC, SO 2 - TO-SO 3 CONVERSION) Average SO 3 concentration may be as high as 50 ppm, exceeding 3% of gross SO 2 content. With unique, high iron content, e.g. western Kentucky coal: up to 10% conversion of SO 2 to SO 3 occurs.

4 UNIT-WIDE SO 2 /SO 3 BEHAVIOR An increment of SO 3 generation occurs in the furnace. Temperature-dependent, catalyzed SO 2 -to-SO 3 conversion occurs in the convective pass, reaching a maximum rate at 1,300 o F (704 o C) flue gas temperature. Rate of SO 3 formation by SCR, increasing SO 3 perhaps by 20+ ppm, is greatest at o F ( o C) and above. Below 600 o F (316 o C) SO 3 hydrates to gaseous sulfuric acid: H 2 SO 4 (v). Condensation of H 2 SO 4 (v) occurs at and below the sulfuric acid dew point temperature, typically as high as 280 o F (138 o C).

5 INFLUENCE OF SOOT BLOWING Low-temperature blowing/cleaning (1,100 to 1,600 o F, i.e. 593 to 871 o C), in removing deposits, increases the rate of SO 2 -to-SO 3 conversion due to tube-metal surface effect. However, (contrariwise), presence of such ash deposits, typically iron-oxide-laden, significantly increases SO 3 formation.

6 INSIGHTS FROM MARCH, 1998, (MOST RECENT) DOE/FETC CONFERENCE ON SO 3 A boiler model study showed that the condition of superheater tube surfaces radically influences catalytic SO 3 formation: –CLEAN:20 ppm –MODERATELY FOULED:70 ppm –HEAVILY FOULED:32 ppm A large, high-SO 3, electric utility unit (without SCR) achieves 60% removal of SO 3 in the air preheater leading to its significant fouling (and derating). Across its exit cross- section, SO 3 varies laterally from 10 to 25 ppm.

7 IMPACT ON AIR PREHEATER OF H 2 SO 4 CONDENSATION IS EXACERBATED BY: Air to gas-side leakage Displacement of flue gas into air stream Enhancement of corrosion due to acid-wetted ash/salt deposit.

8 WITH CO-FIRING OF BIOMASS If more than 10% of total heat input Catalyst activity deterioration may be fifteen times normal

9 EXTERNAL CATALYST REGENERATION, E.G. ULTRASONIC CLEANING 90 TO 100% Recovery of Activity Max. number regenerations: Four or more Amount regenerated to date in Germany: 10,000 cubic meters Cost savings: Major

10 VERY LIMITED, OVERSEAS, HIGH DUST, SCR EXPERIENCE IN U.S.-TYPE, HIGH SULFUR, LOW ASH, COAL SERVICE Japan: Limited to several, early, low-efficiency, ultra- low ammonia-slip installations Germany….none: –All of the several high-sulfur, high-dust, SCR installations fire ultra-high-ash, coal-cleaning middlings, (“ballast coal”), 40% ash content of which greatly mitigates the effect of SO 3 and ammonia slip. –Tail-end SCR design is commonly applied to wet-bottom boilers.

11 JAPANESE SCR PRACTICES FROM 1980s IN HIGH-SULFUR, LOW-ASH, COAL APPLICATIONS Limited NO x Removal Efficiency 10 mm Catalyst Pitch Maintain 330 o C (625 o F), Minimum, at SCR Inlet Ammonia Slip <1 ppm Soot Blowing/Periodic Washing

12 GERMAN SCR DESIGN PRACTICES Standardized, replaceable, catalyst modules Design catalyst-volume criteria tied to maximum design ammonia slip (originally set as high as 5 ppm in low-sulfur service: later 2 ppm) Economizer bypass as necessary to maintain adequate SCR inlet temperature at low load Flow model test at 1:10 or 1:20 scale Provision for a future, spare layer of catalyst Three dimensional, two-phase flow, computer program Enameled steel heating plates in preheater cold-end.

13 GERMAN SCR KNOW-HOW GENERALLY APPLICABLE IN HIGH-SULFUR APPLICATIONS Tight control of inlet temperature Uniform, cross-sectional, flow distribution: –NO x mass flow: + or – 15% max. –NH 3 /NO x Ratio: + or – 3-5% max. –Temperature: + or – 15 o C (27 o F) –Partic. Mass: + or – 30% max. Ammonia Slip: 2 ppm average (1.5 to 3.0 ppm locally) Minimum, catalytic, SO 2 -to-SO 3 conversion When appropriate, (so as to limit SO 3 formation): removal of ‘excess’ catalyst!!! Air preheater enameling Preheater plate surface-profile: easy to blow clean Often apply and justify the alternative, benign, tail-end, SCR design arrangement.

14 INSTRUCTIVE GUIDELINES FROM GERMANY FOR U.S. HIGH SULFUR, LOW ASH, SCR SERVICE Low SO 2 -to-SO 3 catalyst conversion rate, i.e. less than 0.3% Ammonia injection upstream of economizer (?) Alkali injection upstream of air preheater Enameled heating plates on the air preheater, flue-gas side up to 2/3 of the plate height Preheater corrosion protection on the casing and cold side of the rotor structure Optimum preheater soot-blowing means.

15 CONCLUSION Unfettered performance of the in-place, high dust, SCR catalyst is critical for good boiler system operation and reliability. If functioning of the SCR catalyst surface is, or becomes, impaired, e.g. by design inadequacies or significant change in operating conditions, air preheater and fly-ash quality problems may become significant.