Power plant upgrade exceeds performance expectations

The plant at the Jeffrey Energy Center had a history of slagging and fouling issues, which led to boiler derates, reduced efficiency, and frequent cleaning outages. These problems intensified after a major maintenance outage, highlighting the need for an innovative solution.

Fuel Tech’s approach aimed to reduce slag and fouling, improve boiler efficiency and heat rate, and decrease the frequency of derates and outages. The treatment was also designed with an objective to increase soot blowing effectiveness while maintaining fly ash quality to ensure continued sales viability.

As part of the solution, Fuel Tech used detailed computational fluid dynamics (CFD) modeling to understand combustion conditions and guide system design. Dosage was optimized and the TIFI MG™ reagent used to minimize fouling.

The implemented solution delivered strong operational benefits. Overall heat rate improved, and the system proved effective at controlling boiler fouling. Ash deposits became less tenacious and more friable, allowing for easier removal. As a result, cleaning-related derates were reduced, and cleaning outages were extended by 60 days.

Compliance with a 2010 Consent Decree required Jeffrey Energy Center to implement NO_x emissions upgrades, owner Evergy coordinated with the Environmental Protection Agency (EPA) and the State of Kansas. It was decided that an SCR was required to be installed on one unit at a minimum, and Unit 1 was selected. Evergy then decided they wanted to achieve a whole site limit on NOx emissions, without an additional SCR.

The project faced several key challenges, including a limited installation window and elevated furnace exit gas temperatures (FEGT), resulting from high net heat input per plan area, and the use of Powder River Basin (PRB) coal. Effective SNCR reagent distribution was difficult due to the large furnace cross-sectional area and superheat pendants in the upper furnace.

Further, boiler combustion modifications were implemented concurrently with the SNCR system, leading to very low baseline NOx emissions (~0.125lb/MMBtu) and high CO concentrations (~1600 ppm) at the urea injection point.

These factors, combined with the even higher resulting furnace exit gas temperatures (FEGTs), necessitated comprehensive modeling of both the combustion changes and the SNCR design to ensure optimal system performance.

The injection system included four levels of injection using NOXOUT® wall injectors on three levels and Multiple Nozzle Lances (MNLs). A dry urea solutionizing system was employed to support reliable reagent delivery. The system operated effectively across a 35–100% MCR load range, with average NH₃ slip at the economizer maintained around 10 ppm