180 MBtu/hr Fluidized Bed Cogeneration
Energy System
(Illinois Waste Coal)
120,000 lb/hr Steam, 650 psi, 750 deg. F
Owner
New CIE Energy OPCOProject Location
Canton, Illinois
Project Completion
Spring 2009
Project Description
Central Illinois Energy is a 37 million gallon per year ethanol facility
located in an old coal mining district. As coal was harvested from the strip
mines, the fines and dirt were washed out of the good coal creating a byproduct
referred to as "waste coal." Waste coal has a high moisture content, high ash
content and low heating value making it unusable for typical coal fired boilers
and therefore available at a relatively low cost. CIE saw an opportunity to take
advantage of this low cost fuel by utilizing EPI’s flexible fuel fluidized bed
energy system to convert the waste coal byproduct into usable steam and
electricity for use in their ethanol plant. In addition to providing an ability
to utilize low-cost waste fuels, the EPI system could also eliminate volatile
organic compounds from the dryer exhaust gas by utilizing taking the gases into
the fluidized bed system as forced draft air. This eliminated the need for an
expensive thermal oxidizer and its high natural gas consumption.
The waste coal contains high levels of sulfur and approximately 30 percent
ash due to clay content from the coal washing process. EPI’s clean coal
technology utilizes limestone injection in the fluidized bed region for the
initial sulfur capture. A dry scrubber ahead of the baghouse polishes the sulfur
abatement to below permit levels. Oxides of nitrogen, NOx, are abated in two
manners. First, the EPI design provides for a long residence chamber kept at a
relatively low temperature (much like a low NOx gas burner). This limits the
amount of airborne nitrogen conversion to NOx. In addition an EPI designed
selective non-catalytic reduction (SNCR) system is strategically located in the
ideal temperature zone of the vapor space of the fluidized bed chamber. This
system effectively reduces NOx to below permit levels.
Scope of Supply
EPI supplied the complete boiler island from metering bins to the stack.
Specifically included are the waste coal metering system, fluidized bed boiler
system, PLC based control system, gas cleanup and ash handling and storage
systems. The system produces 120,000 lb/hr superheated process steam along with
4 MWe for plant use.
