Demonstration of Nox Emissions Below 0.15 lb/Mbtu in aCyclone Boiler Using In-Furnace Nox Control

摘要

A four week testing program was recently completed to assess the ability of the combination ofdeep staging, Rich Reagent Injection (RRI), and Selective Noncatalytic Reduction (SNCR) toreduce Nox emissions below 0.15 lb/Mbtu in a cyclone fired boiler. The host site for the testswas AmerenUE's Sioux Unit 1, a 540 MW cyclone fired boiler located near St. Louis, MO.This layered approach to Nox reduction is termed the Advanced Layered Technology Approach(ALTA). Installed RRI and SNCR port locations were guided by computational fluid dynamics(CFD) based modeling conducted by REI. During the parametric testing, Nox emissions of0.12 lb/Mbtu were achieved consistently from OFA-only baseline Nox emissions of 0.25lb/Mbtu or less, when firing the typical 80/20 fuel blend of Powder River Basin (PRB) andIllinois #6 coals. From OFA-only baseline levels of 0.20 lb/Mbtu, Nox emissions of 0.12lb/Mbtu were also achieved, but at significantly reduced urea flow rates. Under the deeplystaged conditions that were tested, RRI performance was observed to degrade as higher blendsof Illinois #6 were used. Nox emissions achieved with ALTA while firing a 60/40 blend wereapproximately 0.15 lb/Mbtu. Nox emissions while firing 100% Illinois #6 were approximately0.165 lb/Mbtu. This project was funded by USDOE National Energy TechnologyLaboratory's Innovations for Existing Plants Program.