I. Noya, S. González-García*, G. Feijoo, M.T. Moreira
Department of Chemical Engineering, University of Santiago de Compostela,
Santiago de Compostela, Spain
22nd June 2017
5th International Conference on Sustainable Solid Waste Management
Athens, 21–24 June 2017
42% ORGANIC WASTE
18% PAPER/CARDBOARD
15% PACKAGING WASTE (BRICKS AND PLASTICS)
6% GLASS
How to manage??
In Galicia, each persongenerates ≈1 kg MSW per day
Population ≈ 2,765,940 hab
≈1,000,000 tons of MSW are generated per year
REST FRACTION(nappies, plasters, plates)
TRIAGE RECOVERED MATERIALS(Plastics, Metals, Paper/cardboard)
RECYCLING COMPANIES
PACKAGING WASTE
SORTING PLANT
ORGANIC WASTE + REST
TRIAGE REFUSE‐DERIVED FUEL (RDF) PRODUCTION INCINERATION
LANDFILL
RDF RENEWABLE ENERGY
Biogas RENEWABLE ENERGY
Rejected materials
LANDFILLING
RDF PLANT THERMOELECTRIC PLANT
GLASS
PAPER/CARDBOARD
TRIAGE
ORGANIC WASTE
PRE‐TREATMENT PLANT
PACKAGING WASTE + REST
TRIAGE
LANDFILLBiogas RENEWABLE
ENERGY
LANDFILLING
SORTING PLANT
COMPOSTING COMPOST
AEROBIC FERMENTATION PLANT
RECOVERED MATERIALS(Plastics, Metals, Paper/cardboard)
RECYCLING COMPANIES
GLASS
PAPER/CARDBOARD
LANDFILLING
SCENARIO
COMPOSTING
SCENARIOINCINERATION
SCENARIO
Impact Categories Acronyms Units
Climate Change CC kg CO2 eq
Terrestrial Acidification TA kg SO2 eq
Freshwater Eutrophication FE kg P eq
Marine Eutrophication ME kg N eq
Fossil Depletion FD kg oil eq
Method: ReCiPe Midpoint (H)
FU: 1 kg MSW treated
Scope: cradle‐to‐grave
System expansion approach: Avoided fossil energy Avoided mineral fertilisation Avoided materials
INPUTS
MSW flow
Fossil electricity consumption
Fossil fuels use
Transport activities
OUTPUTS
PRODUCTS EMISSIONS
Renewable electricity
Recovered materials
Compost
Diffuse emissions
Composting stage
Organic (compost) fertilisation N2O
N2O
CO2
INCINERATIONSCENARIO
Fossil fuels use
Renewable electricity generation
Electricity consumption
‐80%
‐60%
‐40%
‐20%
0%
20%
40%
60%
80%
CC TA FE ME FD
kg CO2 eq kg SO2 eq kg P eq kg N eq kg oil eq
Relativ
e contrib
utions
Diffuse emissions Fossil electricity consumption
Fossil fuels use Transport activities
Renewable electricity generation Recovered materials
COMPOSTINGSCENARIO
Recovered materials
Composting emissions
‐100%
‐80%
‐60%
‐40%
‐20%
0%
20%
40%
60%
80%
CC TA FE ME FD
kg CO2 eq kg SO2 eq kg P eq kg N eq kg oil eq
Relativ
e contrib
utions
Difusse emissions Compost emissionsAvoided emissions ‐ compost application Fossil electricity consumptionRenewable electricity generation Recovered materialsTransport activities
Composting stage Compost in soils
‐80%
‐70%
‐60%
‐50%
‐40%
‐30%
‐20%
‐10%
0%
10%
20%
30%
40%
CC TA FE ME FD
kg CO2 eq kg SO2 eq kg P eq kg N eq kg oil eq
Relativ
e contrib
utions
Diffuse emissions Fossil electricity consumption Renewable electricity generation
Fossil fuels use Recovered materials Transport activities
LANDFILLINGSCENARIO
Transport activities
Renewable electricity generation
However, environmental results are highlydependent on the impact category
‐100,00
‐80,00
‐60,00
‐40,00
‐20,00
0,00
20,00
CC TA FE ME FD
Relativ
e relatio
ns (%
)
INCINERATION COMPOSTING LANDFILLING
COMPARATIVE ASSESSMENT
SELECTION OF THE MOST SUSTAINABLE ALTERNATIVE FOR MSW MANAGEMENT IN GALICIA
SOCIAL INDICATORS
ECONOMIC INDICATORS
ENVIRONMENTAL INDICATORS
Employment
Safety and public health
Social perception
INCINERATION SCENARIO
COMPOSTING SCENARIO
LANDFILLINGSCENARIO
Capital costs
O&M costs
Revenues
Climate Change
Terrestrial Acidification
Freshwater Eutrophication
Marine Eutrophication
Fossil Depletion
Criteria
Alternatives
Goal
Saaty (1980). The Analytical Hierarchy Process.
Multicriteria decisiontool to solve decisionproblems affected bymultiple independentfactors
AHP method
EMPLOYMENT SAFETY & PUBLIC HEALTH SOCIAL PERCEPTION
Great number of employees is preferable
Number of employees dealing with waste
treatment
Percentage of the population that are satisfied with MSW
management model
Great percentage of population is preferable
Percentage of valorised waste & Percentage of
waste disposed in landfill
Higher waste valorisationLower waste in landfill
Waste option Year Capital Cost Units Reference
Landfilling 2003 0.0057x0.61 106 € Tsilemou and Panagiotakopoulos (2006)
Incineration2003 0.0049x0.80 106 € Tsilemou and Panagiotakopoulos (2006)
2006 0.0035x0.83 106 € Murphy and McKeogh (2006a,b)
Composting 2005 0.0021x0.76 106 € Tsilemou and Panagiotakopoulos (2005)
x = design capacity (103 t/year)
Waste option Year O&M Cost (O) Units Reference
Landfilling 2003 103.86x‐0.30 €/t Tsilemou and Panagiotakopoulos (2006)
Incineration2003 726.37x‐0.29 €/t Tsilemou and Panagiotakopoulos (2006)
2006 755.97x‐0.29 €/t Murphy and McKeogh (2006a,b)
Composting 2005 1624x‐0.48 €/t Tsilemou and Panagiotakopoulos (2005)
x = plant capacity (103 t/year)
CAPITAL COSTS
O&M COSTS
REVENUES
0,0
0,1
0,2
0,3
0,4
0,5
Economic Social Environmental Overall0,0
0,2
0,4
0,6
0,8
1,0Sc
eanr
ios
scor
e
Crit
eria
sco
re
LANDFILLING INCINERATION COMPOSTING
However, different conclusions can be drawnwhen each criterion is analysed separately
SENSITIVITY ANALYSIS
Composting was found as the best option assuming a similar weight for the
three pillars of sustainability, followed by incineration.
However, AHP method shows as main outcomes can change when each
criterion is analysed separately:
Composting would be again the most favourable alternative from an
environmental perspective.
Incineration would be the preferable option on the basis of popular
opinion (social criteria).
Landfilling would lead to the best economic profile.
A sensitivity analysis may help to estimate how variations on criteria priority
can affect final results.
Questions
Inputs/Outputs SOGAMA LOUSAME NOSTIÁN LANDFILLING
INPUTS
Population (inh) 2282553 86605 396782 2282553MSW flow (t) 1.00 1.00 1.00 1.00Organic waste (t) 0.97 0.34 0.24 0.97Packaging (t) 0.03 0.66 0.76 0.03Electricity use (kWh) 81.0 37.1 37.1* 0.00*NG use (kWh) 527 ‐ ‐ 11.3Transport (t∙km) 51.3 7.87 6.76 51.3
OUTPUTS ‐PRODUCTS
Electricity generation (kWh) 637 10.5 43.3 58.4Electricity origin Incineration + Landfill Landfill AD + Landfill LandfillRecovered materials (kg) 34.0 177 56.8 ‐Paper/Cardboard (kg) 2.55 (7.5%) 58.2 (32.9%) 14.1 (24.8%) ‐Plastics (kg) 10.9 (32.1%) 61.8 (34.9%) 28.9 (50.9%) ‐Glass (kg) 3.30 (9.7%) 7.97 (4.5%) ‐ ‐Metals (kg) 17.3 (50.9%) 19.9 (11.2%) 13.8 (24.3%) ‐Compost (kg) ‐ 6.63 (2% OF) 94.7 (39% OF) ‐
OUTPUTS ‐EMISSIONS
Origin MSW Plant Composting Avoided Composting Avoided LandfillCH4 (air) (kg) 12.0 0.03 ‐ 0.43 ‐ ‐NOx (air) (kg) 0.36 ‐ ‐ ‐ ‐ ‐SOx (air) (kg) 0.03 ‐ ‐ ‐ ‐ ‐N2O (air) (kg) ‐ 2.16 0.004 31.0 0.06 ‐NH3 (air) (kg) ‐ 0.009 0.03 0.13 0.47 ‐NO3
‐ (water) (kg) ‐ 1.16 0.36 16.6 5.19 ‐PO4
‐3 (water) (kg) ‐ 0.003 0.003 0.05 0.04 ‐
SOGAMA:Organic waste = 781089 t/yPRTE = 576651 t/y (74%)Landfill = 204438 t/y (26%)
Product Price Units Reference
Energy 50.14 €/MWh RD 413/2014Orden IET/1045/2014
Plastic (PEAD/PEBD) 895 €/ton ANARPLA (June 2016)
Plastic (PET) 720 €/ton ANARPLA (June 2016)
Paper/Cardboard 83 €/ton ASPAPEL (December 2016)
Metals (Steel) 303 €/ton METALRADAR (March 2017)
Metals (Aluminium) 1785 €/ton METALRADAR (March 2017)
Compost 28 €/ton COGERSA (2016)
Updated costs:
http://www.energiaysociedad.es/manenergia/2‐2‐el‐marco‐normativo‐espanol/http://www.energiaysociedad.es/manenergia/3‐5‐regulacion‐espanola‐de‐las‐energias‐renovables/
i = Interest rate (%)
n = Time period (reference year – present)
Organic fertilisers:
RD 506/2013: Fertilisation (RD 865/2010: Growing media) [RD 535/2017]
Directive 2008/98; Law 22/2011 (raw materials recovered waste)
COMPOST (organic amendment) – Annex IV (RD 506/2013):
Residues from waste treatment plants (19)
Waste from aerobic treatment of MSW (19.05)
Waste from anaerobic treatment of MSW (19.06)
MSW (including selectively collected fractions)
COMPOST Requirements:
% Organic matter/% organic N
Moisture
Heavy metals and microorganisms
Right granulometry
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Relativ
e contrib
ution
Landfill Incineration Recycling Composting/digestion
0
10000
20000
30000
40000
50000
60000
70000
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
GDP
Landfill Incineration Recycling Composting and digestion GDP Linear (GDP)
The Analytical Hierarchy Process (AHP) is a robust and flexible
multicriteria decision making tool designed to deal with complex decision
problems affected by multiple independent factors
Fourmain steps:
1. Definition of the problem
2. Structuration of the decision hierarchy in three levels:
Goal
Criteria
Alternatives
3. Construction of the pairwise comparison matrices
4. Determination of composite weight for each alternativeSaaty (1980). The Analytical
Hierarchy Process.
Criteria i1 Criteria i2 Criteria i3
Criteria i1 1 1/5 1/4
Criteria i2 5 1 1
Criteria i3 4 1 1
Alternative j1 0,5813
Alternative j2 0,3092
Alternative j3 0,1096
ALTERNATIVES/CRITERIA
Preference number Explanation
1 Equally important
3 Weak importance
5 Strong importance
7 Very strong importance
9 Absolute importance
2, 4, 6, 8 Intermediate values
[Saaty’s Fundamental Scale for AHP preference]
CONSISTENCY RATIO
[Eigen vector for alternative priority]
