Slide 1: SNCR Experience on Large Coal-Fired Boilers with Difficult Operating Conditions
SNCR Experience on Large Coal-Fired Boilers with Difficult Operating Conditions Kelly Borgen, Engineer, Jeffrey Energy Center Draft C
Slide 2: Jeffrey Energy Center, St. Marys, Kansas
JEFFREY ENERGY CENTER ST. MARYS, KANSAS • Three (3) eight-corner, tangentially-fired units designed for PRB coal o Units 1, 2, and 3 commissioned in 1978, 1980, & 1983, respectively o CE subcritical drum boilers – 5,050,000 lb/hr capacity o 800 MWg nameplate • Dispatched as part of the Southwest Pow
Slide 3: Project Overview
PROJECT OVERVIEW • 2010 Consent Decree required JEC NOx emissions upgrades o Coordinated effort with the Environmental Protection Agency (EPA) and the State of Kansas SCR required to be installed on one unit at a minimum – selected Unit 1 Option to build a second SCR or comply with a 0.10 lb/mmb
Slide 4: Performance Objectives & Schedule
PERFORMANCE OBJECTIVES & SCHEDULE • Control NOx emissions over large load range (39-100% MCR) o Reduce NOx from ~0.17 to <0.125 lb/mmbtu with combustion modifications o Reduce NOx from 0.125 to <0.115 lb/mmbtu with SNCRs on Units 2 & 3 o Reduce NOx from 0.17 to 0.04 lb/mmbtu with SCR on Unit 1 • Amm
Slide 5: Design Challenges
DESIGN CHALLENGES • Limited time • High FEGT due to high net heat input per plan area and PRB coal Urea + 2 NO + ½ O2 2 N2 + CO2 + H2O • Challenging SNCR reagent distribution 100 250 due to large furnace cross-sectional area 90 NH3 NOx and superheat pendants in upper furnace 80 200 NOx Reduction (
Slide 6: High Upper Furnace Temperature
HIGH UPPER FURNACE TEMPERATURE FULL LOAD - CFD MODEL TOFA and Lower Windbox Elevations Furnace Centerline Superheater Platens Temperature Elevation 1464’ 6 Draft C
Slide 7: Droplet Trajectories and NOx Profile
DROPLET TRAJECTORIES AND NOX PROFILE INJECTION MODELING Level 3: HERT Level 4: MNL NOx Profile Full Load: 65% Load: Wall Injectors Only Wall Injectors and Multiple Nozzle Lances (MNLs) 7 Draft C
Slide 8: System Summary
SYSTEM SUMMARY • Fuel Tech’s injection strategy o Three (3) zones of wall injectors o One (1) zone of MNLs • Zones 1 and 2 consist of NOxOUT® wall injectors • Zone 3 consists of HERT™ wall injectors • Zone 4 consists of multiple nozzle lances (MNLs) 8 Draft C
Slide 9: Solutionizing System
SOLUTIONIZING SYSTEM • JEC has ability to receive both dry and aqueous urea • Solutionizing system scope of supply o 3,100 ft3 dry urea silo o 10,000 gallon solutionizing tank w/ mixer, heaters, and load cells o Solutionizing module with density meter and strainer o Dehumidification unit o Redundanc
Slide 10: Performance Test Results
PERFORMANCE TEST RESULTS Unit Unit 3 Unit 2 Load Condition Full Load Mid Load Full Load Mid Load NOx after Combustion Mods (lb/mmbtu) 0.125 0.108 0.120 0.104 NOx with SNCR (lb/mmbtu) 0.112 0.101 0.107 0.098 NH3 slip (ppm) 8.8 6.9 7.8 5.8 • Met or exceeded performance objectives • Overall NOx perform
Slide 11: JEC 2 and 3 Hourly NOx
JEC 2 AND 3 HOURLY NOX 11 Draft C
Slide 12: JEC 2 and 3 SNCR Chemical Flow
JEC 2 AND 3 SNCR CHEMICAL FLOW 12 Draft C
Slide 13: Bumps Along the Way & Lessons Learned
BUMPS ALONG THE WAY & LESSONS LEARNED • Short timeline resulted in oversights and rework. o Freeze protection o Water pretreatment system o Air compressors • Simultaneous install of combustion modifications and SNCR produced challenges in predicting performance and establishing guarantees. • Coordin
Slide 14: Project Summary
PROJECT SUMMARY • Jeffrey Energy Center is able to comply with the Consent Decree o Flexible emission compliance plan o Significant capital savings o Reduced consumption of urea from lower baseline NOx o Operating cost savings from SNCR operating at low loads • Units control NOx emissions over wide
Slide 15: Questions?
Questions? Draft C