250 Ton/Day Fluid Bed Combustor/Boiler
(Paper and Deinking Sludges)
59 MBtu/hr, 50,500 LB/hr steam @ 160 psi saturated

Project:

Project Location:
Wisconsin

Project Completion:
July 1998

Project Description
In the paper recycling process, waste paper is received and deinked prior to recovery of the fiber. During the deinking process a fiber sludge is generated which contains particles of ink and fibers too short to be converted to a finished paper product. In the past, paper sludges have typically been land filled. With landfill costs rising and the potential for ground water contamination from landfill operations, many environmentally conscious paper producers are recovering the energy from this waste stream.

Due to the high ash and moisture content of deinking sludge, a refined combustion technology must be selected to insure complete energy recovery with minimum air emissions. EPI's fluidized bed technology was chosen as the best fit for both criteria. The fuel supply for this energy recovery project contains 47% ash and 45% moisture, making it especially difficult to burn. Longer residence time and preheated combustion air are incorporated into the EPI design to assure combustion is complete. A 40 MBtu/hr overbed natural gas burner is used to start the fluidized bed and afterburn the combustion products during the startup transition. Process steam generated in the waste heat boiler is used in the paper making process and to dry the sludge from 55 to 45% moisture prior to combustion.

Scope of Supply
The original pilot plant testing, that served as the model for the plant environmental permit, was performed by EPI. EPI is performing the system contract on a turnkey basis including installation and commissioning.

The system includes a fluidized bed combustion cell followed by a waste heat boiler, air preheater, economizer, and baghouse. An EPI metering bin fuels the combustion vessel via a pneumatic injector. Feedback from an SO2 analyzer controls limestone addition with the fuel feed for acid gas abatement as needed. Fluidization air, preheated initially with a steam coil and secondarily with air to air heat exchanger, assures sufficient heat is available to burn the sludge with low CO and VOC emissions. An aqueous ammonia injection system (SNCR) is used to reduce oxides of nitrogen (NOx) to levels below permit requirements. A high efficiency baghouse completes flue gas cleanup prior to discharge.

Energy Products of Idaho
4006 Industrial Ave
Coeur d'Alene, Idaho USA 83815-8928
Phone (208) 765-1611 ~ Fax (208) 765-0503
Email: epi2@energyproducts.com

Copyright © 2008 Energy Products of Idaho
Last modified:  November 12, 2008
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