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Closing the loop – o n-farm fluidised bed combustion of p oultry l itter . Deirdre Lynch Carbolea University of Limerick Ireland [email protected]. Huge energy requirements. Irish Average: 0.71 kWh per bird Recommended: 0.33 kWh Energy Use in Agriculture: SEAI report 2011 - PowerPoint PPT Presentation
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Closing the loop – on-farm fluidised bed combustion
of poultry litter Deirdre Lynch
CarboleaUniversity of Limerick
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Huge energy requirements
Irish Average: 0.71 kWh per bird Recommended: 0.33 kWhEnergy Use in Agriculture: SEAI report 2011
8,000 litres LPG per batch€20,160 per year on heating alone.
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Cyclical supply of litter
1,285 million broiler chickens in EU / year
109 million tonnes of litter in EU / year
Source: FAOSTAT
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Energy
Waste
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Overview
Poultry litterPoultry litter
Fluidised bed
combustor
Emissions
Ash
Energy
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Characterisation of Poultry Litter
Proximate Analysis ar*
Result STDEV +/-
Moisture % BS EN 14774-3:2009
41.82 (18.68 – 51.8) 8.88
Ash %BS EN 14775:2009
9.13 (5.95 – 15.15) 1.98
Volatiles %BS EN 15148:2009
41.9 (35.01 – 56.83) 5.98
Fixed Carbon %by difference
7.81(5.03 – 11.72) 1.61
HHV MJ/kg BS EN 14918:2009
10.55 (8.75 – 14.27) 1.37
*ar = as received
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Characterisation of Poultry LitterUltimate Analysis db*
Result STDEV +/-
Carbon % BS EN 15104:2011
45.17 (42.02 – 48.61) 1.55
Hydrogen % BS EN 15104:2011
5.85 (4.97 – 6.55) 0.49
Nitrogen % BS EN 15104:2011
5.16 (3.83 – 6.40) 0.57
Sulphur % BS EN 15289:2011
0.45(0.29 – 0.6) 0.09
Chlorine % BS EN 15289:2011
0.35 (0.23 – 0.52) 0.23
Oxygen % By difference
27.25 (25.08 – 31.09) 1.41
Ash % BS EN 14775:2009
15.49 (10.61 – 19.58) 1.59
*db = dry basis
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Selection of FBC
– Suitable for poor quality fuels
– Good combustion efficiency
– Waste treated on-site
– Simple technology
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FBC Research Facility
Buffer Tank Hopper
HE 1
HE 2
Baghouse Filter
FBC
Secondary Air
Primary Air
Sand and Ash
Auxillary Diesel Burner
Cyclone
Evaporative Condenser
Ash Collection Points
Cleaned exhaust gas to atmosphere
ID Fan
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FBC Research Facility
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Emissions Monitoring
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Emissions mg Nm¯³ Result STDEV +/- WIDa
PM BS EN 13284-1 0.97 0.81 10HCl BS EN 1911 0.07 0.0094 10NOx BS EN 14792 359 9.0 200SO₂ BS EN 14791 < 0.03 0.0048 50CO BS EN 13526 30.6 2.8 50TOC BS EN 13526 2.2 0.22 10HF BS ISO 15713 <0.03 0.0038 1Cd + Tl BS EN 14385 0.001 0.0001 0.05Hg BS EN 13211 0.0004 0.00005 0.05Heavy metals BS EN 14385
0.041 0.0082 0.5aWaste incineration directive, Annex VReference Conditions: 273K, 101.3kPa, dry gas, 11% oxygen
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Combustion Ash Formation
• Evaporation of moisture
• De-volatilisation (decomposition)
• Char burnout & fragmentation
alkali metals SO₂/SO₃ chlorides
condensation
fine ash < 2 μmcoarse ash
> 2 μm
Poultry Litter Ash
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Fuel K2O CaO P2O5 MgO SO3 Na2OSiO
2Fe2O3 Al2O3
Poultry Litter 28.0 21.0 19.0 11.0 8.1 3.9 2.8 1.2 0.6
Miscanthus 5.2 12.7 6.5 10.8 n/a 1.3 53.3
1.2 2.4
Pine chips 4.5 7.9 1.6 2.4 1.2 1.2 68.2
5.4 7.0
Peat 1.1 9.8 3.5 2.1 11.9 0.1 36.9
13.6 19.8
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SiO2 Al2O3 Fe2O3
CaO MgO P2O5 K2O SO3 Na2O
GA 2.8 0.6 1.2 21.0 11.0 19.0 28.0 8.1 3.9
Bed 52.6 0.5 1.0 9.3 3.0 8.2 16.3 6.4 1.8
HE 1 6.4 0.95 1.0 25.6 8.6 27.5 21.15 5.1 2.6
HE 2 3.5 0.9 1.3 26.0 11.0 22.0 23.0 6.5 3.1
CYC 5.4 1.0 1.2 24.7 10.0 27.9 22.8 5.45 2.9
BH 1.5 0.2 0.3 7.3 2.7 7.75 69.8 6.9 1.2
GA – generated ash at 550°C, CYC – cyclone ash, BH – baghouse ash
Poultry Litter Ash
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Disadvantages of FBC• Ash – high K, Cl and S
– Bed agglomeration
50 mm
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Disadvantages of FBC• Ash – high K, Cl and S
– Bed agglomeration
0%
20%
40%
60%
80%
100%
0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18
Position on line scan (mm)
Si
0.6 mm
0.1 mm
(b)
(a)
Inner Neck Outer
K Ca
P
Mg
S S
S Ca
Na
Fe
K
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Disadvantages of FBC• Ash – high K, Cl and S
– Bed agglomeration
0%
20%
40%
60%
80%
100%
0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18
Position on line scan (mm)
Si
0.6 mm
0.1 mm
(b)
(a)
Inner Neck Outer
K Ca
P
Mg
S S
S Ca
Na
Fe
K
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Disadvantages of FBC• Ash – high K, Cl and S
– Bed agglomeration– Deposit formation
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Disadvantages of FBC• Ash – high K, Cl and S
– Bed agglomeration– Deposit formation
• Solution– Regular maintenance – Soot blowing– Refreshing the bed
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Conclusions• Fluidised bed combustion of poultry
litter 90 % reduction in waste
Low gaseous emissions
Potential fertiliser substitute
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Conclusions• Fluidised bed combustion of poultry
litter
Sustainable, closed loop system
