163 MBtu/hr Fluidized Bed Combustion
System (MDF Resin Impregnated Sander Dust/Board Trim, Hog Fuel)
75 MBtu/hr 750 deg. F gas to dryers
145,000 LB/hr, 300 psi Saturated Steam
Owner
Langboard Inc.
Project Location
Willacoochee, Georgia
Project Completion
March 1998
Project Description
Langboard's medium density fiberboard (MDF) plant in Georgia required a combustion
technology with the latitude to fire both dry and wet fuels while maintaining process
energy requirements and emission limits. The EPI supplied fluidized bed combustor vessel
provides approximately 50 % of its energy to a waste heat boiler producing process steam
with the remaining energy as blended hot gas for the fiber dryers.
Much of the fuel is board trim and sander fines containing urea formaldehyde resins
from the fiberboard process. This fuel promotes furnace and boiler fouling plus generates
oxides of nitrogen (NOx) pollutants if combusted at high temperatures. The EPI fluidized
bed fires the fuel at temperatures generally below the softening temperature of the fuel
ash which significantly reduces the formation of NOx emissions. Yet, longer residence
times plus the turbulent flow design of the fluidized furnace allow complete combustion of
formaldehyde, VOC's and CO demanded by the environmental permit. Secondary NOx is
controlled via ammonia injection, through a selective non-catalytic reduction (SNCR)
system, allowing fuel containing upwards of 3% fuel bound nitrogen to meet compliance. The
injection design also inhibits ammonia slip to the fiber dryers which can damage the
quality of the finished board. A portion of the flue gas exiting the combustor is
directed to the boiler and following economizer. Approximately 84 MBtu/hr is recovered for
steam production while the off-gas is passed through a cyclone and ID fan. The cooled flue
gas discharge of the ID fan is used to blend the 1750 F dryer supply to an inlet
temperature of 750 F in a blend chamber. In addition, press vent air is introduced to the
blend chamber to oxidize organics. Blended flue gas passes through an electrostatic
precipitator for particulate removal prior to introduction to the direct heated dryers.
Scope of Supply
EPI's supply includes fuel storage and metering plus ash collection and storage. The
energy system includes the fluidized bed with tramp removal and startup burner; the
boiler, economizer, fans, cyclone, blend chamber, electrostatic precipitator and emergency
dump stack.
Name
Company
Position
Address
E-mail
Phone
Comments
Energy Products of Idaho
3568 W Industrial Loop
Coeur d'Alene, Idaho USA 83815-8928
Phone (208) 765-1611 ~ Fax (208) 765-0503
Email: epi2@energyproducts.com
Owner
Much of the fuel is board trim and sander fines containing urea formaldehyde resins
from the fiberboard process. This fuel promotes furnace and boiler fouling plus generates
oxides of nitrogen (NOx) pollutants if combusted at high temperatures. The EPI fluidized
bed fires the fuel at temperatures generally below the softening temperature of the fuel
ash which significantly reduces the formation of NOx emissions. Yet, longer residence
times plus the turbulent flow design of the fluidized furnace allow complete combustion of
formaldehyde, VOC's and CO demanded by the environmental permit. Secondary NOx is
controlled via ammonia injection, through a selective non-catalytic reduction (SNCR)
system, allowing fuel containing upwards of 3% fuel bound nitrogen to meet compliance. The
injection design also inhibits ammonia slip to the fiber dryers which can damage the
quality of the finished board. A portion of the flue gas exiting the combustor is
directed to the boiler and following economizer. Approximately 84 MBtu/hr is recovered for
steam production while the off-gas is passed through a cyclone and ID fan. The cooled flue
gas discharge of the ID fan is used to blend the 1750 F dryer supply to an inlet
temperature of 750 F in a blend chamber. In addition, press vent air is introduced to the
blend chamber to oxidize organics. Blended flue gas passes through an electrostatic
precipitator for particulate removal prior to introduction to the direct heated dryers.