Incineration

1
Incineration landfilling

• Håkan Jönsson
• Professor
• Hakan.Jonsson_at_et.slu.se
• Swedish University of Agricultural Sciences

2
Waste incineration

• Renewable fuel 80-90 of Swedish household waste
  is renewable (incineration tax assumed 87.4)
• Heating value 2,5-3,2-4 kWh/kg, 9-11,5-14 MJ/kg
• Heterogeneous dirty fuel
• Extensive flue gas cleaning necessary
• Large plants
• Storage needed but difficult
• Even production over the year
• Difficult when biowaste is included

3
Waste incineration 2008

• 29 incineration plants for household waste, 4.6
  Mton/yr, of which 2.3 Mton/yr household waste
• Sizes gt 200 000/yr 7 plants (Sthlm, Gbg, Lin,
  Mö, Stje, Svall, Ua), 100 000 - 200 000/yr 4
  plants and lt100 000/yr 18 plants
• Energy recovery 12.2 TWh heat (29 of district
  heating) 1.5 TWh electricity (1 of electricity
  use)
• Mass decreases by 75, volume by 90.
• Residues slag 20, fly ash 3-5 (hazardous
  waste)
• Initially introduced for mass and volume reduction

4
Air emissions
Substance 1985 1996 2002 2005 2008 Reduction85-08
Particles,ton 420 33 35 39 30 93
HCl, ton 8400 412 143 98 39 100
SOx, ton 3400 1121 790 310 154 95
NOx, ton 3400 1463 1815 1904 2190 35
Hg, kg 3300 77 21 33 44 99
Cd, kg 400 8 15 (CdTl) 21 (CdTl) 6 (CdTl) gt98
Pb, kg 25 000 214 138 77 136 99
Dioxins, g 90 2 1.1 1.1 0,8 99
5
GRAABS plant, Gothenburg
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Waste incinerator - Uganda
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An advanced incineration system
Fig Persson, 2005
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Flue gas - pollutants

• Particles
• Filter electrostatic and/or textile filters
• NOx Fee 50 SEK/kg NOx (Total 688 milj SEK)
• Ammonia injection 4 NH3 6 NO -gt 5 N2 6 H2O
  4 NH3 4 NO O2 -gt 4 N2 6 H2O
• In furnace SNCR (Selctive Non-Cathalytic
  Reduction 900-1050C, 40-60 reduction)
• After furnace SCR (Selective Cathalytic Reduction
  300-400C, 70-90 reduction)
• HCl
• Alkaline treatment (lime)
• SOx
• Alkaline treatment (lime)
• Heavy metals
• Removed with particles and acids
• Dioxin
• Attaches to active C, removed with particles at
  low temperature

9
Flue gas cleaning - filters

• Cyclone
• Electro filter
• Textile filter (slangfilter)
• Scrubber

Ill Niro A/S
10
Important parameters

• Temperature
• Retention time
• Oxygen
• Turbulence

Fig Persson, 2005
11
Sources of dioxin in Sweden
Fig Persson, 2005
12
Incineration plants

• Grate furnaces (Rosterpannor)
• Most common
• accepts large particles
• sensitive for varying energy content
• hard to control much fuel in system
• grates need water cooling if waste is dry
• Fluidised bed roaster (Fluidbäddpanna)
• Easier to control and adjust to fuel
• Shreading necessary - (max 10 cm)

Fluidised bed roaster
Ill Berman Dille, Westinghouse
13
A modern incineration plant
Fig Persson, 2005
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Flue gas cleaning
Fig Persson, 2005
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Incineration hazardous waste
Fig Persson, 2005
16
Landfill
17
The different stages of a landfill
Fig Persson, 2005
18
Water flows
Fig Persson, 2005
19
Land fill and water flows
Fig Persson, 2005
20
Requirements on liner
Tid Flöde 200 år lt5 l/m2, år 50 år lt50
l/m2, år 1 år
Fig Persson, 2005
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Hydrological considerations
Fig Persson, 2005
22
Collection of landfill gas
2003 414 GWh to district heating, 26 WGWh
electricity and 60 GWh not used.
Fig Persson, 2005
23
A well managed sanitary landfill
Fig Persson, 2005
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Top and bottom liner
Fig Persson, 2005
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Liners - hazardous waste
Fig Persson, 2005
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Landfill biowaste banned

• EU Directive fully implemented 2008
• Containment of waste
• Biowaste goes anaerobic
• Org C -gt CH4 CO2
• Greenhouse gas, 50 collected (optimistic
  figure), 10 oxidised
• Risk of fire
• Sinking top liner damaged more leachate
• Nutrients and heavy metals leaches

Aim totally sealed