S' HELLWEG, G' DOKA, TB HOFSTETTER and K' HUNGERBHLER

1
Life-Cycle Inventory model for the thermal
treatment of municipal solid waste  
S. HELLWEG, G. DOKA, TB HOFSTETTER and K.
HUNGERBÜHLER Safety and Environmental Technology
Group, Swiss Federal Institute of Technology
Zürich (ETHZ) Contact stefanie.hellweg_at_chem.ethz
.ch
Introduction Goal Methods
Results Conclusions References

• The goal was to develop a
• waste-input specific LCI model for
• thermal treatment technologies
• Grate incineration with/without
• proper gas cleaning
• New gasification technologies
• Thermal and mechanical slag treatment
• Thermal filter ash treatment

Waste
H O C S N Pb Cd Hg ...
Gathering and transportation
Ancillary products
Resources
Emissions
Incineration
 
Landfills (slag and filter ash)
Treated waste
Energy
Transfer coefficients represent the relation
between input waste and output to air, water, and
solid incineration residues. A set of transfer
coefficients was provided for each technology.
EXAMPLE modern grate (elements S and Cu)
Burnable waste fraction (g/kg) S 0.33 Cu 0.011
Transfer coefficients () Flue Slag Other
Waste gas resid. water S 0.2 55.4 37.3 7.1 Cu
0.0 80.1 19.9 0.0
Output (g/kg) Flue Slag Other Waste
gas resid. water S 7E-4 0.18 0.12 0.023 Cu 0 0
.009 0.002 0


Several landfill models with different time
horizons are part of the model. The choice of
landfill model is a value-based choice and
therefore left to the user.

• Short-term model (lt100 years) extrapolation of
  measurements.
• Medium- to long-term model based on leaching
  tests (Dutch availability tests)
• 3. Stochastic model Distribution functions

4. Geochemical simulations
 

• An LCI model was developed for the thermal
  treatment of solid waste (different
  technologies). User input data comprise
  composition of waste, technology specification,
  and transport distances.
• The model enables a comparison of thermal
  technologies, of the treatment of different
  materials and of waste management scenarios.
• Different landfill models are provided, which
  consider different time horizons. The choice of
  landfill model is a value-based decision.
• Case study results have shown, that the choice of
  time horizon and landfill model has a crucial
  influence on the results.

Hellweg, S, Hofstetter, TB, Hungerbühler, K
(2001) Modeling waste incineration for
life-cycle inventory analysis in Switzerland,
Environmental Modeling and Assessment 6, 219-235