METHANE de-nox (MdN) Reburn Process for Wood Waste- Fired Stoker Boilers Continuation Projects:

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1 METHANE de-nox (MdN) Reburn Process for Wood Waste- Fired Stoker Boilers Continuation Projects: -Utilization of NCGs as Reburn Fuel in Wood Waste Fired Stoker Boilers -Advanced METHANE de-nox for Wood Waste-Fired Stoker Boilers PI: Stan Wohadlo, Joseph Rabovitser R&D Partners: Fluent Corp, Reaction Engineering International Industry Partners: Boise Paper Solutions, Energy Systems Associates, Detroit Stoker Corporation Sponsors: DOE Industrial Technologies Program, Boise, GRI, Sustaining Membership Program (SMP) This presentation was prepared with the support of the U.S. Department of Energy, under Award No. DE-FC26-00NT However, any opinions, finding, conclusions, or recommendations expressed herein are those of the authors and do not necessarily reflect the views of DOE. 1

2 MdN Performance Goals for the FPI Reduce both operating costs and air emissions through advanced combustionbased technology in Hog Fuel Boilers Increase utilization of wood wastes as boiler fuel Improve boiler operability, reliability, & efficiency Improve boiler environmental performance Provide cost effective & efficient route for destruction/utilization waste gases Increase self-generated power capacity 2

3 Outline Hog Fuel Boiler Challenges Research Focus Technology Description Agenda 2020 projects I. Falls Project Results Base Project DeRidder Project Status Continuation Project Port Hudson Optimization Studies Continuation Project Commercial Design Packages MdN Development & Deployment Summary Commercialization 3

4 Hog Fuel Boiler Challenges Hog fuel issues Stoker grate Combustion air distribution Fan capacities Auxiliary burners Waste gas combustion Existing NOx, CO and particulate controls Firing practices 4

5 Research Focus Strategic use of Natural Gas in combustion process - more than just heating value Small natural gas inputs provide: Combustion stabilization Improved startup and load following Stabilize burning of low/variable quality fuels Emissions reduction NO x, CO, particulate Efficiency improvement Improved carbon burnout Reduced excess air 5

6 Technology Description 3-stage Combustion for Stoker Boilers Injection of reburn fuel (preference is natural gas)/fgr near the grate for intense gas mixing Oxygen-deficient atmosphere above the grate to retard NO x formation More uniform furnace temperatures Overfire Combustible Air Burnout Zone with higher average and lower peak NO and temperatures) : x Reburn Fuel NOx Precursor increased fuel drying above the & FGR Reduction Zone grate Bark & NOx Formation Sludge Zone improved bark/sludge combustion capacity Reduced fuel and ash piling on Undergrate air Ash the grate Injection of OFA at a higher furnace elevation to improve burnout 6

7 Implementation of the Technology 3-Fundamental Elements Selection Flexible based on Client Objectives MdN OFA MdN FGR MdN Reburn Fuel Injection NG/FGR Bark & Sludge Ash UGA 7

8 Technology Applications Minnesota (MSW) 60% NO x reduction 50% CO reduction +2% eff. Virginia (Coal) 240 MW - 8 boilers 70% NO x reduction + 2% eff. Japan (MSW) 2 WTE plants 50% NO x reduction 80% Dioxin reduction MN and LA (Bark and Sludge) Klb/h bark/sludge boilers 30-40% NO x reduction Up to +2% eff. 8

9 Technology Development and Deployment Summary Base Project International Falls, MN demo completed, in continuous service-hfb Wallula, WA baseline testing completed-hfb Port Hudson, LA in continuous full scale service-hfb Continuation Project DeRidder, LA baseline testing completed-hfb Commercialization Discussion between ESA and a Mill owner underway with potential of 4 commercial deployments of elements of MdN Technology, CFD modeling is in progress-hfb ESA retrofitted 18 additional coal-fired stoker boilers with elements of MdN technology, satisfying client objectives 9

10 Agenda 2020 Projects - I Falls Increase firing of clarifier solids with high fuelbound nitrogen content Increase boiler thermal efficiency through improved burnout and lower excess air Maintain NOx and CO emissions at or below permit limit 10

11 I. Falls Boiler #2 Long-Term Results 1999 / 2000 Comparison Ratio 1999 vs ,100 7, #2 Boiler Sludge burned NOx (tons) Boiler Eff. % 10 9 BTU gas use (tons) 52 tons less NOx emitted $770,000 savings reported after 1 st year operation 3900 tons less sludge landfilled 167 billion BTUs less gas energy used billion BTUs less gas energy used 11

12 Continuation Project DeRidder Safe and effective disposal of LVHC and SOG Reduced auxiliary fuel (natural gas) use Boiler efficiency improvement NOx reduction up to 40% 12

13 3-Stage Combustion with NCG/SOG as Reburn Fuel Overfire Air SOG NG/FGR LVHC Woodwaste Ash Extension of basic technology Benefits: Provides an alternative to NCG/SOG injection in gas burners Removes need for gas burners during NCG/SOG injection and Reduces rate of NO X formed by ammonia in SOG compared to current scheme Reduces consumption of natural gas by up to 25% more than basic reburn Combustible Burnout Zone NO x NO x Precursor Reduction Zone NO x Formation Zone Undergrate air process 13

14 NCG/SOG Baseline Test Conclusions Reburn plus improved bark and air distribution can meet project objectives NCG & SOG must be injected separately NCG & SOG flow & composition highly variable - natural gas/fgr injection system can compensate flow and fuel value variations Decoupling SOG from gas burners can reduce gas usage and ammonia conversion to NOx Reducing excess air will compensate for added FGR flow in furnace 14

15 DeRidder Project In November of 2004, mill was acquired by a new owner. The NCG/SOG technology demonstration work was placed on hold. Due to continued uncertainty at the mill, the field demonstration was canceled. Work was replaced with development of a MdN Commercial design report to serve as a resource for commercialization of the technology 15

16 Port Hudson Optimization Study Reburn System Design CFD model-based approach Evaluate OFA and FGR use Existing and/or new nozzles Size, placement, flow conditions Compare effects on furnace conditions that influence NOx, CO and particulate 16

17 Optimization Study Oxygen Contours - Baseline Upper-level OFA Gas Cofir ing burners Mid-level OFA Windswept spouts Gas/FGR nozzles Fines Reinjection nozzles 17

18 Optimization Study CO Contours with MdN 18

19 Optimization Study Based on findings from the study, changes were made to Port Hudson s OFA and FGR arrangement Results for the optimized system were: Additional NOx reduction of 30% Improved CO burnout at lower excess air Reduced co-firing gas consumption by 50% 19

20 MdN Commercial-scale Design Report Created a commercial-scale design report to promote acceptance of technology in FPI Design package includes results from CFD modeling and engineering recommendations for construction of MdN systems for four types of woodwaste stoker boilers 20

21 MdN Commercial-scale Design Report Stoker boiler with a square furnace, traveling grate and LVHC NCG injection through furnace rear wall Stoker boiler with a rectangular furnace, stationary pinhole grate, and no NCG Stoker boiler with a rectangular furnace, traveling rotograte, and HVLC NCG injection under the grate Stoker boiler with a square furnace, vibrating hydrograte (water-cooled), and LVHC NCG injected through furnace rear wall 21

22 Project Summary Work is essentially complete, draft final report submitted GTI continues collaboration with ESA in promotion of technology on an as need basis. Participated with ESA in a field evaluation of I Falls stoker boiler in November 2005 Technology license agreements in place with ESA and Takuma ESA has installed 18 MdN coal-fired stoker systems over the last two years 22

23 Energy Savings In U.S pulp and paper mills, approximately 150 woodwaste-fired stoker boilers are estimated in operation. A typical boiler configuration has a thermal input of 300 mmbtu/h (200 kpph steam) With Mdn,overall thermal efficiency increases between 1 to 2%. Potential energy savings per boiler is 4.5 mmbtu/h Annual energy savings based on a 80% capacity factor is 31,500 mmbtu/yr-unit Based on a 25% reduction in natural gas consumption (15% of heat input); a savings of $400,000 is estimated per year (80% capacity factor) 23

24 Other Benefits Emission reduction to 0.20 lb NOx/mmBtu is achievable. Based on boiler uncontrolled emission of lb NOx/mmBtu, total emissions reduction equals about 80 tons of NOx/yr-unit (80% capacity factor) Equivalent to removing about 1,300 cars from the road yearly Increased steam production by 2 to 5% 24

25 Commercialization Drivers NOx environmental regulations Cost of NOx emission credits Capital Investment Main competition to MdN technology include improved combustion/ofa Systems and SNCR technology SNCR is expensive to install and more expensive to operate and maintain 25

26 Commercialization Considerations Evaluate other reburn fuels candidates such as highly reactive sawdust, syngas, other combustible waste streams Co-fired hog fuel boilers continue to offer a good opportunity for MdN technology 26

27 Commercialization Plan Target Market Natural gas co-fired Hog Fuel Boilers populating the pulp and paper industry firing wood, woodwaste, biosolids and waste gases Heat input rates above 250 mmbtu/h Location in Ozone Transport Region, California and non-attainment regions in Texas (Houston/Dallas) Based on estimates of bark-fired stokers in the paper industry; there is an opportunity for 2 to 3 MdN retrofits per year during the next decade 27

28 Commercialization Plan Technology Licensees Environmental Systems Associates (ESA), a limited liability corporation located in Pittsburgh PA. Licensed for coal and wood applications in the U.S. Takuma, licensed for MSW applications in Japan 28