John Weeda, Great River Energy - Speaker at the marcus evans Generation Summit 2012 held in San Antonio, TX, delivered his presentation on the topic Operating Experience with Fluidized Bed Coal Dryer at Coal Creek Generating Station
Operating Experience with Fluidized Bed Coal Dryer at Coal Creek Generating Station - John Weeda, Great River Energy
Generation Summit G ti S it February 7-8, 2012 San Antonio, TX John WeedaDirector, North Dakota Generation Great River Energy
Great River Energy gy• Generation & transmission cooperati e cooperative• 28 member cooperatives in MN and WI• Serving 645 000 homes & businesses 645,000• 850 employees• $850 million revenue• $3.3 billion total assets• Investment grade debt• 2,800+ MW of generation• 4,500+ miles of transmission lines
Background – The "Triple B tt Th "T i l Bottom Line" Li "• Great River Energy has a commitment to provide customers with: Rates Reliability – Stable rates – Reliable electricity – Environmental stewardship Environment• Members annually approve: – Rates – New projects – Environmental investments
A AP Premier E i Example of th l f the Innovative Spirit
Coal Creek Station Units 1&2 • 2 X 600 MW Tangentially Fired, Dual Furnace • 8 X 8 burners, plus SOFA • Eight Pulverizers per Unit • Mine Mouth, ND Lignite o Contract thru 2045 o 6,200 BTU/lb (14.4 MJ/kg) o 38% moisture o Approximately 8M tons/yr pp y y • Commissioned 1979, 1981 • Wet FGD’s from original design • Cl Closed L d Loop C li Cooling • DC transmission to Minnesota
Why should DryFine technology be of i t f interest to you? tt ? Advanced Ultra-Supercritical at 1350F/1400F (732C/760C) Ultra-SuperCritical at 1256F/1292F (680C/700C) Low-T Fuel Drying Ultra-SuperCritical at 1120F/1120F (604C/604C) Dual Reheat Natural Draft Cooling Tower Reduce cooling tower approach temperature Low-T Air Pre-Pre-heating Low-T Feedwater Pre-heating Reduce Air Heater Leakage (6% to 1%) 0% 5% 10% 15% Heat Rate Improvement, % BaselineFigure 2-24Comparison of Heat Rate Improvement TechnologiesBaseline is 1080°F/1080°F/3800 psi steam cycle (582°C/582°C/262 bar), 87.2% efficient boiler firing PRB coal withmechanical draft cooling towers. Baseline Unit Heat Rate is 8,982 Btu/kWh (9,497 kJ/kWh).From:CoalFleet Guideline for Advanced Pulverized Coal Power Plants: Version 5 EPRI Palo Alto, CA: 2009. 1015698. 5. EPRI, Alto 2009 1015698
Problem Statement: The Friday Afternoon Brainstorm Question• Plant performance is based on 6,800 BTU/lb (15.8 MJ/kg) fuel ( ( g) (with normal margins), but delivered fuel HHV has rarely exceeded 6,200 BTU/lb (14.4 MJ/kg)• As a result…. result • Lost Boiler And Cycle Efficiency – 9% Higher Coal Flow Rate Than Design – 20 MW Of Station Service Power – 20% Higher Flue Gas Flow Rate Than Design – High Exit Gas Temperature • Lost Spare Mill Capability • Increased Operating And Maintenance Costs • Flue Gas Flow Limited Scrubbers!
Culture of Innovation• Is a “Friday afternoon” brainstorm session allowed, encouraged or frowned upon?• Do employees have the big picture of what improvements in their area of responsibility can do for the company?• Is plant performance a “tracking” program or an “improvement” p g program?
Solution• Objective…. • Restore lost performance by removing moisture in the incoming fuel stream just prior to bunkering• How…. • Employ waste heat to reduce moisture content of the lignite conveyed to the bunkers• Approach…. • Demonstrate and Select Basic Drying Process Concept • Develop “Proof Of Concept” Pilot Plant • Develop Dryer Design And Predictive Performance Modeling • Prototype Full Scale Dryer Design • Integrate Full Scale Commercial Demonstration Into Existing Plant Project Coal Pile Phase 1 Phase 2 Testing, Initial Pilot Dryer Prototype Commercial Fluidized Bed 2 Ton/hr Dryer Application Dryer Design 2003- Present 112Ton/hr 2009 2002 2005-2009
Culture of Innovation• Are employees free to try new things?• Is failure acceptable?• Is there some funding available for improvement development?• Would you support a pilot study?• Is a prototype a taboo thought?
Culture of Innovation• Are integrated solutions encouraged?• Is boiler efficiency equivalent to environmental controls?• Is reduced maintenance cost a valid factor in economic evaluation?• Can you take credit for reduced company staff time without a layoff?
Prototype Coal Dryer yp y• Maximum capacity - 112 5 tons/hr M i it 112.5 t /h• Removed approx. ¼ of coal moisture. – Dried lignite from 38.5% to 29.5% moisture – Improved HHV from 6,200 BTU/lb (14.4 MJ/kg) to 7,045 BTU/lb (16.4 (16 4 MJ/kg)• Fully automated operation, integrated into the plant control system.• Six patent applications on dryer design and control filed by GRE (two awarded).
Culture of Innovation• Will your operators support operation of a prototype?• How will maintenance support the need to keep a prototype running?• Is collaboration embraced as a way to leverage knowledge and innovation?
Boiler Efficiency Improvement from the Prototype 3.0 Theory Test Result oiler Efficienc Improvement [% Abs] 2.5 2.0 20 1.5 ction cy Target Moisture Reduc 1.0 Bo 0.5 05 0.0 0 1 2 3 4 5 6 7 8 9 10 Reduction inTotal Moisture in Coal [% Abs]
Segregation Stream from the Prototype Sulfur and Hg in Segregation Stream 60.00% Mercury 50.00% 40.00% %S in UC 30.00%% %Hg in UC 20.00% Sulfur 10.00% 0.00% 5/31/06 6/3/06 6/5/06 6/6/06 6/7/06 6/8/06 6/9/06 6/12/06 6/13/06 6/14/06 date
The Transition from Prototype to Commercial• Pursue the one unit at a time original concept?• Evaluating least cost options
DryFining – the clear choice 0 nefits 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 mulative Cos Net Ben sts Present Value difference between the cases exceeds $292 million in value CummConfidential 19 Alternative Case - No Coal Drying Base Case - Coal Drying
Culture of Innovation• Is a least cost model vs. an ROI model acceptable?• Does the board trust management enough to authorize a project like this?• Will management and the board support the rough spots in the road as serial number one issues of budget, schedule, and startup issues need resolution. resolution
Culture of Innovation• Are you willing to make proactive environmental improvements?• Do your employees have enough ownership of their equipment to make it thru serial number one issues? Not just the engineers- how about your Mechanics, Electrical j g y , and Instrument Technicians, Operators, Fuel Handlers and others? Do they work collaboratively or throw problems back and forth? y y p
SO2 Reduction 0.900 0.800 0.700 N btu 0.600lB/mILLION 0.500 0.400 GREAT RIVER ENERGY Coal Creek Station 0.300 DryFining Full Load SOx Impact JCKennedy ‐ 5/14/2010 0.200 10/14/09 11/3/09 23 11/23/09 8-Sep-11 12/13/09 1/2/10 1/22/10 2/11/10 3/3/10 3/23/10 4/12/10
NOx Reduction 0.300 GREAT RIVER ENERGY Coal Creek Station - Unit #2 Hourly Full Load NOx Readings - Oct 2009 to April 2010 5/25/2010 - JCKennedy 0.250NOx (lb/1 6 BTU) 10 0.200 0.150 0.100 10/14/09 11/3/09 11/23/09 12/13/09 1/2/10 1/22/10 2/11/10 3/3/10 3/23/10 4/12/10
Summary: HgT y g Coal Creek Unit 1: sCEM: Total Mercury 20 Wet Coal BaselineTotal Mercury Concentration in Flue Gas [μg/dNm ] 183 Dried Coal 16 g 14 12 n 10 8 6 y 4 2 0 APH Inlet FGD Inlet FGD Bypass FGD Outlet Stack Measurement Location
DryFining Results25% less H2O - dry lignite from 38 to 29% moisture, improvingHHV from 6,100 to 6,800 BTU/lb 54% less SO2 - Segregation of ash minerals, plus improvedcollection efficiency 40% less Hg - Segregation of ash minerals, plus improvedcollection efficiency 32% less NOX - Reduced volumetric release rate improved rate,fineness and air & fuel distribution to furnace4% less CO2 - 4% improved cycle efficiency
Meeting the Challenge of Marketing the Technology• DOE requirement that the technology be made commercially available to others• Repayment to DOE based in part on sale of technology• Developing commercialization partners• GRE not DryFine Inc DryFine, Inc.
Process integrations (completed) g ( p )• Gasifiers – Integrated Gasification Combined Cycle – Coal to Liquids• Super Critical Pulverized Coal• Activated Carbon• Oxy-fuel firing• Confidentiality agreements in place• 50% Global reserves would benefit
Other GRE Successes from aBusiness Improvement CultureB i I t C lt
Efficiency ImprovementsTurbine blades DryFiningCooling Towers beneficiationSimulator 4%, 800 000 4% 800,000 tons totalVentilationVariable packingFans/VFD sFans/VFD’s Over $316,000,000 invested in environmental and efficiencyControls improvements since 1979Leak detectionCompressed air605,771 tons total
Precision Maintenance Successes• Cooling Tower F C li T Fans-from 2 f il f failures/yr at $36,000 each t 12 years / t $36 000 h to with no failures• Heater Drains Pump- annual rebuild to 8+ year life saving $5000/year• Condensate pumps- 7 year life to 15+ years saving $49,000/pump X 6 pumps• Valve maintenance- saving $14,000 to $100,000/year• Boiler Feed pumps increase life between overhauls avoided pumps- purchase of new pump for $550,000
Concluding Point of View Whatever you call your drive forexcellence,excellence a host of opportunities await you which, like DryFine, will improve your bottom line when you foster innovation.