Fuel Tech, Inc. · NASDAQ:FTEK
Fuel Tech — Reinhold Environmental 2016 NOx-Combustion-CCR Round Table
50 slides from Fuel Tech's conference presentation, Feb 2, 2016
Slide 1: Broaden the Operating Range of Coal Fired Units by Lowering the Minimum Operating Temperature
Orlando, FL February 2, 2016 Broaden the Operating Range of Coal Fired Units by Lowering the Minimum Operating Temperature Reinhold Environmental 2016 NOx-Combustion-CCR Round Table Volker Rummenhohl
Slide 2: Agenda
Agenda • Introduction • Basics of SCR Minimum Operating Temperature (MOT) • Variety of solutions to reduce MOT • Conclusions
Slide 3: Introduction
Introduction • Improving unit dispatch in an ever changing coal electricity generation market place requires the lowest possible unit load. • The boiler is often limited by the Minimum Operating Temperature of the SCR system. 3
Slide 4: MOT
MOT • The Minimum Operating Temperature is the temperature below which ammonia and sulfur trioxide combine to form ammonium bisulfate (ABS). • NH3 + SO3 +H2O NH4HSO4 • ABS deposits in the micro pores and reduces the catalyst activity. • The ABS deposits can be removed at higher temperatures. • The M
Slide 5: ABS Formation Temperature Example
Example 640 620 ABS Forma*on Temperature F 600 Catalyst NOx Reduction PPM 580 (=Ammonia Concentration) 560 150 200 540 250 300 400 520 500 1 6 11 16 21 26 31 36 41 46 SO3 PPM
Slide 6: Economizer Temperature Characteristic
Economizer Temperature Characteristic Temperature VS Load 800 700 MOT 600 500 Temperature F 400 300 200 100 0 0 20 40 60 80 100 120 140 160 180 200 Load MW
Slide 7: Solutions
Solutions • Verify operating data at low loads • Operate below MOT • Increase economizer outlet temperature • Reduce ammonia concentration in the flue gas • Reduce sulfur trioxide concentration in the flue gas • Combination of the above
Slide 8: NOx VS Load
NOx VS Load
Slide 9: Economizer Temperature Characteristic
Economizer Temperature Characteristic Temperature VS Load 800 700 635 F Design 600 MOT 500 150 MW Temperature F 400 300 200 100 0 0 20 40 60 80 100 120 140 160 180 200 Load MW
Slide 10: Verification of Low Load Operating Data
Verification of Low Load Operating Data • NOx inlet • NOx distribution • SO2 inlet • SO2 distribution • SO3 inlet • SO3 distribution • Temperature inlet • Temperature distribution • Ammonia slip
Slide 11: Verification of Low Load Operating Data
Verification of Low Load Operating Data Temperature VS Load 800 700 Design 600 610 F 120 MW MOT 500 Temperature F 400 300 200 100 0 0 20 40 60 80 100 120 140 160 180 200 Load MW
Slide 12: Verification of Low Load Operating Data
Verification of Low Load Operating Data Temperature VS Load 800 700 Design 600 MOT 590 F 90 MW 500 Temperature F 400 300 200 100 0 0 20 40 60 80 100 120 140 160 180 200 Load MW
Slide 13: Reduce Ammonia concentration
Reduce Ammonia concentration
Slide 14: Economizer Temperature Characteristic
Economizer Temperature Characteristic Temperature VS Load 800 700 MOT Design 600 MOT 500 80 MW with Temperature F reduced NOx 400 removal efficiency 300 200 100 0 0 20 40 60 80 100 120 140 160 180 200 Load MW
Slide 15: Operation Below MOT
Operation Below MOT • Deterioration of Ammonia/NOx profile inside the catalyst mostly on high sulfur units • Time dependent • Other sulfite formation
Slide 16: Operating Below MOT on High Sulfur Unit
Operating Below MOT on High Sulfur Unit • 500 MW unit wall fired • Bituminous coal with 3% sulfur • Full load performance test o Guaranteed NOx removal exceeded o Ammonia slip not detectable o NOx outlet distribution +/- 10 PPM
Slide 17: Operating Below MOT on High Sulfur Unit
Operating Below MOT on High Sulfur Unit • Low load first performance test o As full load test • Low load second performance test o Guaranteed NOx removal exceeded o Ammonia slip 2 PPM o NOx outlet distribution +/- 20 PPM • Low load third performance test o Guaranteed NOx removal exceeded o Ammonia s
Slide 18: Bio Mass Unit
Bio Mass Unit • SCR clean side arrangement (444°F) - downstream of baghouse and DSI. • Most catalyst poisons have condensed on ash and removed in bag house. • DSI removes 70-90% of SOx • Minimum operating temperature of 423°F based on design SO2 / SO3 values at baghouse outlet. • Additional design c
Slide 19: Bio Mass Unit
Bio Mass Unit • Boiler first fire July 7, 2013 • SCR Baseline testing began on November 19, 2013. • NOx removal set point target set at 0.078 lb/MMBTU and met. • Ammonia slip testing done at a set point of 0.045 lb/ MMBTU. Set point was met and no ammonia slip excursions found. • Initial compliance
Slide 20: Bio Mass Unit Current Operation
Bio Mass Unit Current Operation • NOx Inlet 0.138 - 0.155 lb/MMBTU • NOx Outlet 0.032 - 0.075 lb/MMBTU • Temperature 375°F - 423°F • Pressure Drop (SCR) less than 2” Wg CONFIDENTIAL 20
Slide 21: Operation Below MOT: Local SCR Inlet Temperature
Operation Below MOT 420 415 410 Local SCR Inlet Temperature F 405 400 395 390 385 380 375 370 11/16/13 11/17/13 11/17/13 11/18/13 11/18/13 11/19/13 11/19/13 11/20/13 11/20/13 11/21/13 11/21/13 Time
Slide 22: Bio Mass Unit
Bio Mass Unit • Testing done at 4,000 and 8,000 hours CONFIDENTIAL 22
Slide 23: Economizer Gas Side Bypass
Economizer Gas Side Bypass
Slide 24: Economizer Gas Side Bypass
Economizer Gas Side Bypass Stuart Economizer Temperatures 850 Temperature ( F) 800 o 750 700 650 600 550 500 250 300 350 400 450 500 550 600 650 Load (MW) Economizer Outlet Economizer Inlet
Slide 25: Economizer Gas Side Bypass
Economizer Gas Side Bypass Stuart Current SCR Inlet Temperature Note: Economizer Bypass Must Remain Open if Load is Under 495 MW Economizer Bypass is Insufficient for Loads Under 380 MW 635 625 615 Temperature ( F) o 605 595 585 575 565 555 545 250 300 350 400 450 500 550 600 650 Load (MW)
Slide 26: Economizer Gas Side Bypass Full Load (610 MW)
Economizer Gas Side Bypass 660 640 Full Load (610 MW) Temperature ( oF) 620 350 MW (Bypass Closed) 600 325 MW Bypass 580 Open Low Load (250 MW) 560 540 19 15 16 11 17 18 12 13 14 20 10 10 10 10 10 10 10 10 10 10 Thermocouples (West to East)
Slide 27: Economizer Gas Side Bypass
Economizer Gas Side Bypass
Slide 28: Economizer Gas Side Bypass
Economizer Gas Side Bypass pro-STAR 3.2 Temperature Fahrenheit NX
Slide 29: Economizer Gas Side Bypass
Economizer Gas Side Bypass Temperature Fahrenheit
Slide 30: Economizer Gas Side Bypass
Economizer Gas Side Bypass Temperature Fahrenheit
Slide 31: Possible Solution
Possible Solution
Slide 32: Economizer Water Side Bypass
Economizer Water Side Bypass • Pro: No flue gas mixing issues • Con: Many times difficult to retrofit • No flow water flow through part of the economizer
Slide 33: SO3 Reduction With Targeted In-Furnace Injection TIFI
SO3 Reduction With Targeted In-Furnace Injection TIFI • Mg(OH)2 calcines to high surface area MgO • Direct Reaction with MgO o MgO + SO3 => MgSO4 o MgO + NH4HSO4 => MgSO4 + NH3+ H2O • Lower Furnace Temperature o Decreased Oxidation Rate • More Balanced Furnace o Reduced Excess Oxygen • Reduced Slag
Slide 34: MOT Reduction With Targeted In-Furnace Injection TIFI
MOT Reduction With Targeted In-Furnace Injection TIFI • 600 MW Wall Fired. • Illinois Basin Coal. • Need for Greater Low Load Flexibility. • New Low Load Operations began Aug 2013 and continues through present. • Original Low Load 430 MW – reduced to 275 MW 34
Slide 35: SO3 Reduction With Targeted In-Furnace Injection TIFI
SO3 Reduction With Targeted In-Furnace Injection TIFI
Slide 36: SO3 Reduction With Targeted In-Furnace Injection TIFI
SO3 Reduction With Targeted In-Furnace Injection TIFI • Lower furnace injection (zones 1 -- 4) is optimal for slag/fouling control o MgO reacts with ash to modify ash fusion temperature o MgO captures SO3 • Zone 5 injection is more efficient for SO3 control and still provides slag & fouling control
Slide 37: Optimized Mg(OH)2 Injection for SO3 Control
Optimized Mg(OH)2 Injection for SO3 Control APHin SCR dance floor Inject here ESP inlet
Slide 38: Predictive Performance Model for SO3 Control
Predictive Performance Model for SO3 Control
Slide 39: Predictive Performance Model for SO3 Control
Predictive Performance Model for SO3 Control 100 90 80 70 SO3 Reduction-(-%) 60 50 40 Mg(OH)2,3[SO3]3=3253ppm,380%3coverage 30 Ca(OH)23EPRI,3[SO3]=25ppm,100%3 coverage 20 Ca(OH)23EPRI,3[SO3]=25ppm,3 80%3coverage 10 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 Mg(OH)2 or-Ca(OH)2 Feed-Rate--(dry-basis,-lb/hr/1000-
Slide 40: SO3 Tests
SO3 Tests • Modified EPA Method 8A Controlled Condensate • Single train sampling o Preliminary tests conducted to understand cause (dose) and effect (reduction) relationship o One SO3 train measured AH inlet at low load, ramp period and full load • Six train full test protocol • SO3 measurement loca
Slide 41: Results at Low Load (< 400 MW)
Results at Low Load (< 400 MWg) 65 Low$Load$(<$400$MW)$. Airheater$Inlet$(B$side) 60 55 50 45 [SO3]-(ppmvdc,-3%-O2) 40 35 3/0 30 5/0 25 3/2 20 3/3 7/2 15 3/6 10 2/7 3/15 5 0 0 2 4 6 8 10 12 14 16 18 20 Total-Dose-(Zone-1A4-+-Zone-5) • Uncontrolled SO3 concentration is 51 – 63 ppmvdc (at 3.0% O2) • S
Slide 42: Results During Ramp
Results During Ramp 50 50 45 45 40 40 3,lbs/ton,(Zone,1B4) 3,lbs/ton,(Zone,5) [SO3],(ppmvdc,,3%,O2) [SO3],(ppmvdc,,3%,O2) 35 35 30 30 25 7,lbs/ton,(Zone,1C4) 25 2,lbs/ton,(Zone,5) 20 20 15 15 10 2,lbs/ton,(Zone,1C4) 10 3,lbs/ton,(Zone,1B4) 7,lbs/ton,(Zone,5) 7,lbs/ton,(Zone,5) 5 5 0 0 250 300 350 40
Slide 43: Results at Full Load
Results at Full Load 50 Full$Load$(>$580$MW)$1 Airheater$Inlet$(B$side) 45 40 35 [SO3]/(ppmvdc,/3%/O2) 30 25 20 7/2 15 7/0 3/0 10 3/3 2/7 5 0 0 1 2 3 4 5 6 7 8 9 10 Total&Dose&(Zone&1.4&+&Zone&5) Proprietary and Confidential
Slide 44: Low Load Results
Low Load Results Low Load - A side Low Load - A side 40 1.60% 35 1.40% 3/0b 3/0b [SO3] ppmvdc (3% O2) 30 1.20% 3/2 25 3/2 1.00% % of SO2 20 0.80% 5/0 5/0 15 0.60% 10 0.40% 5 0.20% 0 0.00% 1 2 3 1 2 3 Measurement LocaXon Measurement LocaXon Low Load - B side Low Load - B side 30 1.40% 25 3/0b 1.20% 3
Slide 45: Ramp Results
Ramp Results 40 Ramp - A side 1.80% Ramp - A side 35 1.60% 3/7.5 3/7.5 [SO3] ppmvdc (3% O2) 30 1.40% 3/7.5 1.20% 3/7.5 25 % of SO2 1.00% 20 3/15 0.80% 3/15 15 0.60% 10 0.40% 5 0.20% 0 0.00% 1 2 3 1 2 3 Measurement LocaXon Measurement LocaXon 30 Ramp - B side 1.40% Ramp - B side 25 3/0 1.20% 3/0 [SO3
Slide 46: Full Load Results
Full Load Results Full Load - A side Full Load - A side 25 1.20% 3/2a 3/2a 1.00% 20 [SO3] ppmvdc (3% O2) 3/2b 3/2b 0.80% 3/2c 15 3/2c % of SO2 0.60% 3/2d 3/2d 10 0.40% 5 0.20% 0 0.00% 1 2 3 1 2 3 Measurement LocaXon Measurement LocaXon Full Load - B side Full Load - B side 20 1.20% 18 3/2a 1.00% 3/2
Slide 47: New Minimum Loads
New Minimum Loads • New limiXng load factor – combusXon stability • Wider operaXng range may pay for all day chemical consumpXon
Slide 48: Additional Solutions
Additional Solutions • Duct burner to raise the temperature o Pro: Provides the entire load range o Con: Economics • Gas co-firing o Reduces SO3 and NOx concentration in the flue gas • Burner improvements to reduce the NOx concentration • SNCR to reduce the NOx concentration
Slide 49: Conclusions
Conclusions • Several options are available to broaden the SCR operating range. • Precise definition of low load operating conditions is mandatory. • Operation below MOT can be detrimental if there is no mechanism to preclude ABS formation in the air pre heater. • Economic evaluation important for o
Slide 50: Thank You Questions?
Thank You Questions?
Fuel Tech — Reinhold Environmental 2016 NOx-Combustion-CCR Round Table on 6ix