1. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Comparing the Life Cycle Assessment (LCA) Performance of
Residual Waste Treatment Solutions
Nick Cawthorne
Golder Associates (UK) Ltd
ORGANIZADO POR: CON LA COLABORACIÓN DE:

2. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Background
• EU Landfill Directive (Article 5 Landfill Diversion Targets)
• Objective to reduce environmental impact of landfill
(particularly global warming) and increase recycling and
recovery;
• Mechanisms: landfill bans, separate collection, recycling
targets and landfill tax;
• These mechanisms encourage residual waste diversion but
don't optimise alternative solution;
• Alternative waste solution will have very different impacts
associated with waste treatment and very different
benefits associated with energy and materials recovery;
• Life Cycle Assessment (LCA) considers overall
environmental performance of waste solution options.

3. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Objective of this LCA Study
Compare Life Cycle environmental performance of different
residual waste treatment solutions.
In consideration of:
• Treatment and Transport impacts;
• Residues disposal;
• Materials recovery benefit;
• Energy recovery benefit.

4. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Life Cycle Assessment Model
• Waste Resource Assessment Tool for the Environment
(WRATE) is the LCA tool used in UK for waste
management applications;
• Background database contains standard LCI data from
ecoinvent centre Switzerland and detailed process data
for many waste treatment options;
• Results available for different impact assessments
including global warming potential and resource
depletion;
• Developed by Golder Associates and ERM for
Environment Agency in UK.

5. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
WRATE Modelling
• Seven scenarios for the management of residual waste.
• Assumptions and Limitations
– Waste composition data - Typical UK Residual Waste;
– 250,000 tonnes waste;
– Vehicles are ‘waste collection vehicles’ or ‘Intermodal
Road Transport’ travelling 25 km, road type split is 80%
urban/20% rural;
– The electricity mix selected is year 2011, UK;
– All landfills - HDPE composite liner and HDPE cap;
– Waste treatment uses existing processes in WRATE for
each treatment type.

6. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Scenarios Modelled
• Scenario 1 - Waste to Energy (Power);
• Scenario 2 - Mechanical Biological Treatment (RDF);
• Scenario 3 - Materials Recycling Facility, MRF
(Recycling and RDF);
• Scenario 4 - Mechanical Biological Treatment
(Stabilisation);
• Scenario 5 - Mechanical Biological Treatment
(Recycling and Anerobic Digestion);
• Scenario 6 - Waste to Energy
(Combined Heat and Power, CHP); and
• Scenario 7 - Landfill.
Note: Scenarios 2, 3 RDF to cement kiln;
Scenarios 2, 3, 5 waste residues to off site WtE;
Scenario 5 AD Digestate landfilled as stabilite.

7. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Materials Recycling
Facility (MRF)

8. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Mechanical
Biological
Treatment Plant

9. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Waste to Energy plant
(WtE)

10. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Refuse Derived Fuel
(RDF)
Cement kiln

11. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Scenario WasteResources Conference(Power)
Waste to
1: Waste to (power)
to Energy Energy
Non-ferrous Aluminium
Ferrous Ferrous
OTHER
Residual Waste Commercial Incinerators IBA IBA Recycling
vehicles Power
To Landfill Landfill
Date 11/05/2011

12. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Scenario 5 - MBT (Anerobic Digestion)
Waste to Resources Conference
MBT (AD)
Paper and card Paper
Dense Plastic Plastics
Plastics-1
Flat Plastic
Glass Glass-1
Non-Ferrous Aluminium
Ferrous
Ferrous
Non-Ferrous
Residual Waste To MBT MBT and AD Ferrous
OTHER
Incinerators IBA Recycling
Power
IBA
Landfill
Stabilite to
Landfill
To Landfill

13. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Material Recovery Rates
Scenario Number Paper & Plastic Dense Glass Ferrous Non RDF IBA
and Treatment Card Film Plastic (tonnes) (tonnes) Ferrous (tonnes) (tonnes)
Solution (tonnes) (tonnes) (tonnes) (tonnes)
1 WtE (Power) 7,566 1,150 54,956
2 MBT (RDF) 6,734 1,769 110,277 28,552
MRF
3 (Recycling, 5,497 11,269 8,384 2,243 17,964 39,303
RDF)
MBT
4 3,723 7,258 1,986 18,988
(Stabilisation)
5 MBT (AD) 41,324 1,984 2,977 5,580 8,339 2,070 4,925
6 WtE (CHP) 7,566 1,150 54,956
7 Landfill

14. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Results – Global Warming Potential: Multiple Impact Assessments
Treatment and
Collection Intermediate Facilities Recovery
Transportation Recycling Landfill
European Person Equivalent
Scenario: 1 2 3 4 5 6 7

15. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Results – Global Warming Potential (Combined)
Kg CO2 Eq.
Scenario: 1 2 3 4 5 6 7

16. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Best Performing Solutions - Global Warming Potential
1. Scenario 3 – Materials Recycling Facility, MRF (Recycling and
RDF);
2. Scenario 6 – Waste to Energy (Combined Heat and Power, CHP)
3. Scenario 1 – Waste to Energy (Power)
4. Scenario 2 – Mechanical Biological Treatment (RDF)
5. Scenario 5 – Mechanical Biological Treatment (Anerobic
Digestion)
6. Scenario 4 – Mechanical Biological Treatment (Stabilisation)
7. Scenario 7 – Landfill.
Note: Results very different if MBT/MRF residues to landfill not WtE

17. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Explanation of Results
Scenario 3 – Materials Recycling Facility, MRF (Recycling and RDF)
• Recycling of dense plastic, ferrous metal and glass;
• Non recycled waste to energy recovery, RDF to cement kiln and
residues WtE;
• No waste to landfill.
More carbon benefit is achieved by recycling a given amount of
plastic or paper than can be achieved by combusting for energy
recovery in a WtE plant or in a cement kiln as RDF.
Scenario 6 WtE (CHP), Scenario 1 – WtE (Power) and Scenario 2 – MBT
(RDF)
• Less Recycling (metal recycling only);
• Non recycled waste to energy recovery, RDF and WtE;
• No waste to landfill.

18. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Explanation of Results
Scenario 5 – MBT (AD) and Scenario 4 – MBT
(Stabilisation)
• Recycling plastic, paper/card, metals and glass;
• Low energy recovery (AD only) net of energy
consumption for treatment;
• Significant landfill disposal.
Scenario 7 (landfill)
• All waste landfilled;
• No material or energy recovery, other than via landfill
gas utilisation.

19. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Observations
• Best performing solutions include a high degree of
recycling and energy recovery of all other waste;
• Plastic, paper/card and glass can only be recycled
before combustion;
• Recovery rates of metals, particularly non ferrous
metal, is likely to be higher prior to combustion than
recovery from bottom ash;
• Carbon benefit is particularly sensitive to non ferrous
metal recovery;
• Any solution which includes significant landfilling of
stabilised waste will perform less well;
• Any solution which includes landfilling of residue
fractions will perform less well.

20. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Conclusions
• The carbon (global warming potential) performance of
residual waste treatment solutions is enhanced where the
maximum amount of materials are recycled followed by
combustion of all residues for energy recovery (RDF or WtE);
• More carbon is recovered by material recycling than by
energy recovery of the same waste;
• Comment: Financial incentives typically focused more on
energy recovery than material recycling;
• Landfilling of stabilised waste or residues greatly reduces the
performance of the solution.

21. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Conclusions
• MBT/MRF and WtE typically seen as two fundamentally
separate approaches;
• Optimisation of MBT/MRF requires WtE of residues
(possibly at separate facility);
• Optimisation of WtE requires recycling of materials in
advance (MRF before WtE);
• Optimisation converges the two approaches towards a
single solution;
• Maximum material recycling followed by Energy
recovery and zero landfill;
• Energy recovery by RDF or WtE.

22. Los retos en la gestión de residuos urbanos en una economía globalizada
Els reptes en la gestió de residus urbans en una economia globalitzada
Challenges in waste management in a globalized economy
Muchas Gracias
Nick Cawthorne
ncawthorne@golder.com