Final Report KING COUNTY FUEL CELL DEMONSTRATION PROJECT Prepared for Department of U.S. Environmental Protection Agency Natural Resources and Parks Wastewater Treatment Division April 2009 Prepared by Department of Natural Resources and Parks Wastewater Treatment Division King County Fuel Cell Demonstration Project Prepared for U.S. Environmental Protection Agency April 2009 Prepared by For comments or questions, contact: Bob Bucher King County Wastewater Treatment Division 1400 Utah St. West M.S. WTP-NR-0100 Seattle, WA 98199 [email protected] This information is available in alternative formats on request at 206-684-1280 (voice) or 711 (TTY) King County Fuel Cell Demonstration Project ii Table of Contents Executive Summary...................................................................................................................vii SECTION 1 Introduction..................................................................................................... 1-1 Background........................................................................................................................................... 1-1 Project Timeline.................................................................................................................................... 1-3 Project Teams........................................................................................................................................ 1-3 Report Organization ............................................................................................................................ 1-4 SECTION 2 Fuel Cell Technology and Configuration .................................................. 2-1 Molten Carbonate Fuel Cell Technology .......................................................................................... 2-1 Overview of King County’s Demonstration Fuel Cell System ...................................................... 2-2 Fuel Processing Block .......................................................................................................................... 2-4 Power Section Block............................................................................................................................. 2-7 Power Conditioning Block.................................................................................................................. 2-9 Ancillary Systems................................................................................................................................. 2-9 Fuel Cell Power Plant Configuration .............................................................................................. 2-10 SECTION 3 Integration of Power Plant with Site Utilities and Fuel Sources .......... 3-1 Utility Services...................................................................................................................................... 3-2 Fuel Gas Systems.................................................................................................................................. 3-2 Communications Systems................................................................................................................... 3-2 SECTION 4 Project Chronology ........................................................................................ 4-1 Design and Construction—March 2000 Through March 2004....................................................... 4-1 Commissioning—March 2004 Through June 2004 .......................................................................... 4-2 Demonstration Period—June 2004 Through June 2006 .................................................................. 4-3 SECTION 5 Power Plant Performance.............................................................................. 5-1 Data Collection Methods..................................................................................................................... 5-1 Performance Summary........................................................................................................................ 5-1 Performance Goal 1—Deliver high quality and quantity of gas to the fuel cell.......................... 5-2 Performance Goal 2— Produce energy as designed on natural gas and digester gas................ 5-3 Performance Goal 3— Produce minimal noise ................................................................................ 5-6 Performance Goal 4—Produce energy at a minimal cost ............................................................... 5-7 Performance Goal 5— Produce minimal air emissions while operating on either natural gas or digester gas................................................................................................................................ 5-9 Performance Goal 6—Produce wastewater with no adverse impacts on treatment plant ...... 5-10 Performance Goal 7—Operate the power plant on a continuous basis...................................... 5-11 Performance Goal 8—Operate the fuel cell efficiently.................................................................. 5-12 Performance Goal 9—Monitor and control the power plant remotely....................................... 5-12 Performance Goal 10—Remove hydrogen sulfide effectively from digester gas...................... 5-12 Performance Goal 11—Dispose of power plant solid waste at a reasonable cost ..................... 5-14 Performance Goal 12—Recover waste heat from the power plant ............................................. 5-15 Performance Goal 13—Demonstrate output turndown on power plant (operation at less than 100 percent capacity)................................................................................................................. 5-15 Performance Goal 14—Demonstrate power output design ramp rate ....................................... 5-16 Performance Goal 15—Meet the design service life of the fuel cell stacks................................. 5-16 Performance Goal 16—Confirm ability to restart from a trip condition .................................... 5-17 Performance Goal 17—Confirm ability to quickly start the power plant................................... 5-17 King County Fuel Cell Demonstration Project iii SECTION 6 Operational Challenges and Design Improvements ............................... 6-1 Integration with Wastewater Treatment Plant Utilities.................................................................. 6-1 Power Plant Module Malfunctions.................................................................................................... 6-2 Fuel Gas Treatment Systems............................................................................................................... 6-3 Ancillary Systems................................................................................................................................. 6-3 Power Plant Distributed Control System..........................................................................................6-4 Power Plant Modifications.................................................................................................................. 6-4 SECTION 7 Conclusions and Recommendations........................................................... 7-1 Tables Table 1-1. Operations and Testing Project Team — King County Fuel Cell Demonstration Project .......................................................................................................................................... 1-3 Table 1-2. Peer Review Team — King County Fuel Cell Demonstration Project ............................ 1-4 Table 5-1. Summary of Performance Goal Achievement .................................................................... 5-2 Table 5-2. Efficiency Measurement ........................................................................................................ 5-4 Table 5-3. Parasitic Loads ........................................................................................................................ 5-5 Table 5-4. Natural Gas Performance Summary.................................................................................... 5-5 Table 5-5. Digester Gas Performance Summary................................................................................... 5-5 Table 5-6. Measured Noise Levels (power plant operating on digester gas) ................................... 5-7 Table 5-7. King County Labor Hours..................................................................................................... 5-8 Table 5-8. Materials and Consumables Costs ....................................................................................... 5-8 Table 5-9. Energy Production Costs and King County Labor Full-Time Equivalents .................... 5-9 Table 5-10. Fuel Cell Power Plant Stack Emission Results While Operating on Natural Gas (Scrubbed Digester Gas) – July 2004...................................................................................... 5-10 Table 5-11. Hydrogen Sulfide Sampling Results for Digester Gas Treatment System ................. 5-13 Table 5-12. Results of Gas Chromatography Analysis for Sulfur Compounds in Natural Gas Samples from Desulfurizer Outlet B...................................................................................... 5-14 Table 5-13. Power Plant Waste Heat Recovery Unit Performance................................................... 5-15 Table 6-1. Power Plant Design Improvements Resulting from Demonstration Project.................. 6-5 Figures Figure 2-1. Electrochemical Conversions in