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Title: Enhancing the use of coals by gas reburning-sorbent injection. Volume 3, Gas reburning-sorbent injection at Edwards Unit 1, Central Illinois Light Company

Technical Report ·
DOI:https://doi.org/10.2172/53497· OSTI ID:53497

Design work has been completed for a Gas Reburning-Sorbent Injection (GR-SI) system to reduce emissions of NO{sub x}, and SO{sub 2} from a wall fired unit. A GR-SI system was designed for Central Illinois Light Company`s Edwards Station Unit 1, located in Bartonville, Illinois. The unit is rated at 117 MW(e) (net) and is front wall fired with a pulverized bituminous coal blend. The goal of the project was to reduce emissions of NO{sub x} by 60%, from the ``as found`` baseline of 0.98 lb/MBtu (420 mg/MJ), and to reduce emissions of S0{sub 2} by 50%. Since the unit currently fires a blend of high sulfur Illinois coal and low sulfur Kentucky coal to meet an S0{sub 2} limit Of 1.8 lb/MBtu (770 mg/MJ), the goal at this site was amended to meeting this limit while increasing the fraction of high sulfur coal to 57% from the current 15% level. GR-SI requires injection of natural gas into the furnace at the level of the top burner row, creating a fuel-rich zone in which NO{sub x} formed in the coal zone is reduced to N{sub 2}. The design natural gas input corresponds to 18% of the total heat input. Burnout (overfire) air is injected at a higher elevation to burn out fuel combustible matter at a normal excess air level of 18%. Recycled flue gas is used to increase the reburning fuel jet momentum, resulting in enhanced mixing. Recycled flue gas is also used to cool the top row of burners which would not be in service during GR operation. Dry hydrated lime sorbent is injected into the upper furnace to react with S0{sub 2}, forming solid CaSO{sub 4} and CaSO{sub 3}, which are collected by the ESP. The SI system design was optimized with respect to gas temperature, injection air flow rate, and sorbent dispersion. Sorbent injection air flow is equal to 3% of the combustion air. The design includes modifications of the ESP, sootblowing, and ash handling systems.

Research Organization:
Energy and Environmental Research Corp., Bartonville, IL (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States); Gas Research Inst., Chicago, IL (United States); Illinois Dept. of Energy and Natural Resources, Springfield, IL (United States)
DOE Contract Number:
FC22-87PC79796
OSTI ID:
53497
Report Number(s):
DOE/PC/79796-T38-Vol.3; ON: DE95009447
Resource Relation:
Other Information: PBD: Oct 1994
Country of Publication:
United States
Language:
English