Fuel Tech, Inc. · NASDAQ:FTEK
Fuel Tech — International Biomass Conference 2016
29 slides from Fuel Tech's conference presentation, Apr 11, 2016
Slide 1: Corrosion, Slag and Fouling Challenges for Boilers Burning Biomass Fuels
International Biomass Conference April 11-14, 2016 Charlotte NC Corrosion, Slag and Fouling Challenges for Boilers Burning Biomass Fuels Chris Smyrniotis, VP Fuel Chem Development
Slide 2: Agenda
Agenda • Deposit formation and impacts • Fuel Tech’s TIFI® Technology • Technology Selection for Biomass • Mechanism of Operation • Impacts of TIFI on Corrosion • TIFI Program Detail • Questions & Comments 2
Slide 3: Slag and Fouling Mechanism
Slag and Fouling Mechanism • Slag deposition o Condensation of molten, viscous inorganic species on colder surfaces (e.g. heat transfer tubes) o Typically on water walls, superheater tubes, generating bank tubes • Fouling o Deposition of gaseous species onto colder surfaces (e.g. heat transfer tubes
Slide 4: Impacts of Slag/Fouling on Unit Operations
Impacts of Slag/Fouling on Unit Operations • Restricted gas flow path o Build up between tubes results in pressure differential o Induced draft (ID) fan load increases to maintain prescribed draft • Reduced heat transfer efficiency o Diminished heat absorption o Decreased steam output o Heat rate de
Slide 5: TIFI Targeted In-Furnace Injection
TIFI® Targeted In-Furnace Injection™ TIFI nozzle injecting magnesium hydroxide 5
Slide 6: Slag/Fouling Control with TIFI
Slag/Fouling Control with TIFI • Targeted injection towards problem areas o Reagent slurry injection o Small quantities of chemical (sub-stoichiometric for deposit control) • Deposit control and SO3 plume mitigation o Furnace to stack o Minimum operating temperature (MOT) issues with APH • Increased
Slide 7: Key Technologies to Control Slagging & Fouling
Key Technologies to Control Slagging & Fouling Untreated Slag • Deposit Analysis • Computational fluid dynamics (CFD) • Injection technology TIFI Treated Slag • Chemical technology • Combustion expertise 7
Slide 8: Efficient Chemical Delivery to Problem Areas
Efficient Chemical Delivery to Problem Areas Particle calcination/disintegration Distribution/reaction Furnace Injection superheated H2O Reagent Particle Reagent Particles Flue Gas Flow (d0.5 – 1.6-2.3 μm) (d0.5 – 0.06-0.3 μm) (300-30,000 particles) Deposits embedded with reagent particles 8
Slide 9: Impact on Deposit Physical Properties
Impact on Deposit Physical Properties Scanning Electron Microscope (SEM) at 5.5X magnification NOTE: pore size comparison Deposit without TIFI® Deposit treated with TIFI® Numerous small pores with thick walls Larger pores with thin walls 9
Slide 10: Hard Slag Formation Controlled
Hard Slag Formation Controlled Furnace side After TIFI® treatment • More pores • Less dense • Softer • Easier to crumble/remove • Example of friable slag created via TIFI use Before TIFI® treatment • Tenacious • Less pores and smaller • Hard • More dense Wall side 10
Slide 11: Technology Selection
Technology Selection 11
Slide 12: Scientific Approach to Deposit Control
Scientific Approach to Deposit Control • Fuel and deposit samples analyzed o Chemistry, physical properties, and ash fusion temperatures • Several chemical additives available o Which one is most effective? • Laboratory screening studies conducted o Determination of cost-effective additives Compress
Slide 13: Superheater Deposit Compression Strengths
Superheater Deposit Compression Strengths Compression Test Results 9000 8000 7000 Compression Max Load (lbs) 6000 5000 4000 3000 2000 1000 0 Baseline MG Hi MG Med MG Lo ATH Hi ATH Med ATH Lo Kaolin Hi Kaolin Med Kaolin Lo Fly ash Hi Fly ash Fly ash Lo MG/ATH MG/ATH MG/ATH Med (1:2) Hi (1:2) Med (1:2
Slide 14: Economizer Deposit Compression Strengths
Economizer Deposit Compression Strengths 4500 Compression Strength Applied to Breakage (lbs) 4000 3500 3000 2500 2000 1500 1000 500 0 Baseline TIFI MG TIFI MG TIFI MG ATH Hi ATH Med ATH Low Kaolin Hi Kaolin Kaolin Hi Med Low Med Low 14
Slide 15: Additive Selection Summary
Additive Selection Summary • Mg(OH)2 and ATH are effective at reducing strengths of superheater and economizer deposits • ATH: efficacy is sensitive to slight variations fly ash chemistry o Can lose control and strengthen deposit o Use of ATH alone is not recommended 15
Slide 16: Corrosion Control using TIFI
Corrosion Control using TIFI 16
Slide 17: Controlling Corrosion
Controlling Corrosion • Chloride-induced corrosion is directly related to the presence of slag/fouling deposits • Deposit-free heat transfer surfaces result in significantly lower metal loss rates due to corrosion • TIFI reduces corrosion rates by keeping surfaces clean
Slide 18: Mechanism of Corrosion
Mechanism of Corrosion Key processes Key processes - Vapor-phase and small- (T= 540°C/1000°F) - Inertial impaction particle diffusion, — Vapor-phase deposition of NaOH, thermophoresis, and Na,SO,? electrophoresis. - Adherence of particles - combined effe ° raleiaiert ha is of particle stickiness and
Slide 19: Mechanism of Corrosion
Mechanism of Corrosion • Process starts with condensation of potassium & sodium vapor on tube surface • Small sticky particles cling, melt and stay • Larger particles stick to the mass • Can be less than the thickness of the tube to many times tube thickness • Chlorides and other anions migrate thro
Slide 20: Controlling Corrosion: Probe Metal Sample
Controlling Corrosion: Probe Metal Sample • Pre-weighed sample • Target tube metallurgy • Installed on probe inserted through furnace wall port • Gas flow from upper left to lower right • Sample removed and measured at intervals 20
Slide 21: Controlling Corrosion: Temperature Control
Controlling Corrosion: Temperature Control • Flow control valve regulates cooling air flow • Control panel sends signal for temperature control point • Data logger logs temperature data
Slide 22: Controlling Corrosion: Probe Mount
Controlling Corrosion: Probe Mount • Probe mount provides air flow through annulus of probe to inside of metal sample • Kam Lok mounted • Thermocouples wired through center to both ends and center inside of probe 22
Slide 23: Controlling Corrosion: Corrosion Probe Test Summary
Controlling Corrosion: Corrosion Probe Test Summary gas flow top • Probe metallurgy = boiler metallurgy • Air‐cooled to tube skin temperature in problem area • Probe diameter routinely measured to quantify metal loss rate 23
Slide 24: Nee
Nee pi nt) | New- Noexposure in the furnace 1.7600, ra TIFI Treated for 289 days x 730 02633 SZ |
Slide 25: Impact of TIFI on Corrosion
Impact of TIFI on Corrosion • Maintaining a clean furnace results in significantly reduced metal loss rates • Demonstrated in numerous systems: o Biomass units burning biomass fuels o Units burning opportunity biomass and blends o Municipal waste incinerators (high Na/K, >1000 ppm Cl-) o Black liquo
Slide 26: Enhanced Efficacy Through Targeted Application
Enhanced Efficacy Through Targeted Application 26
Slide 27: Targeting Chemistry to Problem Areas
Targeting Chemistry to Problem Areas • Fuel analyses/combustion/laboratory data used to predict problem areas o Visual inspections are used to validate/tune model • TIFI program is designed to specifically target problem areas 27
Slide 28: Opportunity to Switch Fuels/Co-Fire
Opportunity to Switch Fuels/Co-Fire • Design: burn coal with Tfusion= 1150° (Green) • Goal: burn coal with Tfusion = 1370°C (Blue) Low Cost Fuel Tmelt = 1150 oC • Less costly fuel (Blue) • Ability to co-fire different fuels • Biomass Design Fuel • Oil Tmelt = 1370 oC • Coal • RDF • TDF 28
Slide 29: Optimizing the Injection Strategy
Optimizing the Injection Strategy Right Half Furnace Model 20 injector array 14 injector array 29