FULLSCALE POULTRY LITTER TEST BURN RESULTS Diane Brown and John Sherwell Maryland Department of Natu

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FULL-SCALE POULTRY LITTER TEST BURN RESULTSDiane
Brown and John SherwellMaryland Department of
Natural Resources, Power Plant Research
ProgramAndrew Cressman, Gary Walters and Julie
WheelerEnvironmental Resources Management
Project Background
Conclusions
ECICF consists of 2 wood-fired boilers stoker
spreader fuel distribution water-cooled vibrating
fuel grate (hydrograte) 80 MMBtu/hr heat
input 50,000 pph steam production capacity 4 MW
Electric power capacity Cogen facility not
capable of meeting electric thermal demands of
the institution Fall of 97 - pfiesteria outbreak
lead to investigation of poultry litter as
potential alternative fuel at ECI Converted
boiler could consume 54,000 tons of litter/year
ABSTRACT The Maryland Department of Natural
Resources, Power Plant Research Program (PPRP) is
charged with evaluating impacts to Marylands
natural resources arising from electric power
generation. PPRP has been involved for several
years in evaluating operational alternatives for
the cogeneration plant at Eastern Correctional
Institution (ECI), a correctional facility on
Marylands Eastern Shore. The existing
wood-fired boilers provide hot water for the
prisons thermal requirements as well as steam
for the electric generating turbines excess
electric power is sold. The two existing units,
each rated at 40 MMBtu/hr heat input, are not
capable of meeting all of ECIs peak thermal and
electric demands. PPRP studied the feasibility of
burning poultry litter as an alternative to wood
chips, and this paper reports the major findings
of the proof of concept test burn. The use of
poultry litter as a fuel is of interest because
it would reduce the amount of poultry waste used
on the Eastern Shore as fertilizer. The land
application of this litter is an important source
of reduced nitrogen emissions, both as
volatilized ammonia and through leaching of
soluble organic forms. Further, fertilizer use of
poultry litter can result in excessive
phosphorous application, which may contribute to
the outbreaks of the toxic microorganism
Pfisteria piscicida on the Eastern Shore.
During 1999 a detailed assessment evaluating the
feasibility and costs of burning poultry litter
at ECI was conducted by PPRP that found that
while poultry litter is comparable to wood chips
in a number of ways (i.e., heating value and
moisture content), a number of important
differences exist. Specifically, poultry litter
is high in ash and fines content, high in
nitrogen, and high in alkali metals and chloride.
The high ash content in conjunction with the
elevated concentrations of alkali metals and
chloride cause poultry litter to be characterized
as a slagging fuel. Because of these findings,
the study concluded that a number of
modifications would be necessary to convert the
boilers to burn chicken litter. The study
initially estimated the cost of these
modifications at approximately 6 million.
Still, even at these costs a life cycle analysis
indicated that conversion of the two wood-fired
boilers would results in a total life cycle
(20-year) cost that is lower than current
conditions. Additionally, it was estimated that
the converted boilers could consume an estimated
54,000 tons of poultry litter annually. The
results of these studies have promoted the use of
chicken litter as a fuel on the Delmarva
Peninsular and several new facilities are being
proposed.

• - Retrofit at ECI is not recommended.
• Poultry litter is suitable for cubing and using
  as a fuel
• - The ash has value as a fertilizer
• - A hydrograte is not recommended for firing
  poultry litter due to high ash content of the
  fuel and required high shaking rate (travelling
  grate preferred)
• - Air emissions factors are in good agreement
  with factors reported in UK
• Poultry litter ash is not a RCRA hazardous waste
• - No OSHA action levels exceeded for airborne
  metals, dust, organic vapors, or ammonia
• - The cubing process resulted in 6-fold reduction
  in microorganism CFUs however, appropriate PPE
  and industrial hygiene practices should be
  employed for operations involving raw or cubed
  litter

Test Burn Study
Availability 350,000 tons/yr of litter in
3-county area Fuel Characteristics heat and
moisture content similar to wood Suitability of
existing stoker-fired, direct combustion boilers
for conversion ECI similar to commercial
litter-fired units in UK
Health Safety

• Pathogen viability analysis
• Raw litter 6 CFUs
• Cubed litter 1.1 CFUs
• 85 reduction in microbial counts achieved via
  cubing process
• 2 pathogenic (Spore Bacilli) species identified
  in cubed litter
• Confirmed need for HASP, esp. appropriate PPE
• Air sampling results
• All metals, dust and organic vapor below
  respective OSHA PELs

Chicken litter plant operating in the UK
Cubed Poultry Litter
Future Directions
The utility of poultry litter as a fuel has been
demonstrated also that the reduced nitrogen
content of the litter can be effectively
managed. There is now considerable interest in
using poultry litter as a fuel - Allen Family
Foods/CHx gasification with combustion
turbines. 40,000 tons/year. Actively in
licensing process - Fibroshore moving grate.
250,000 Tons/year. Preliminary engineering
studies - Eastern Shore Forest Products/ BG
Technologies Gasification, material separation.
50,000 tons/year. Preliminary engineering
studies
ECI Cogeneration Facility
Air Emissions
Fuel Analysis Summary
95 as TKN
Below DL
Ash Analysis
Litter firing in furnace.
Gray/white material (primarily alkalis) deposited
on internal surfaces of boiler Bottom ash
analyzed for RCRA metals (TCLP) none detected
greater than threshold regulatory limits Ash
content of the fuel was approximately 15 by
weight
TKN 700ppm 99.9 removal
Reference NRC Committee on the Causes and
Management of Coastal Eutrophication, R.W.
Howarth, Chair. (2000) Coastal Ocean Waters.
Understanding and Reducing the Effects of
Nutrient Pollution, National Academy Press,
Washington, D.C.