the application of life-cycle analysis to integrated solid ... · the application of life-cycle...

The Application of Life-Cycle Analysis to Integrated Solid Waste ManagementPlanning for the State of Delaware

Morton A. BarlazS. Ranji RanjithanP. Ozge Kaplan

North Carolina State University

Objective

Use a planning tool to evaluate multiple alternatives for solid waste management in Delaware

Consider cost, emissions, energy consumptionConsider scenarios that may differ from current practice

Presentation Outline

SWM-LCI BackgroundModeling ApproachData CollectionCounty-specific SWM Strategies

Least-cost scenarios• Combinations of Curbside Recycling, Yard Waste

Composting and CombustionConsideration of Environmental Emissions

Statewide SWM StrategiesAlternative SWM StrategiesUncertainty analysis Summary

Solid Waste Management is Complex: Many Options are Interrelated

Recycling vs. waste-to-energy for recyclable paper and plastics (newsprint, cardboard, plastic)

Relative benefits of landfilling or composting yard waste if we plan to recover methane?

How do the cost and environmental emissions change if we add a material to a recycling program?

MRF(Material Recovery

Facilities)

TREATMENTcomposting, combustion

DISPOSALCOLLECTION

REMANUFACTURING

Ash Landfill

Landfill

Aerobic Compostingof Yard Waste

Refuse DerivedFuel

Combustion withPower Generation

1. Mixed refuse MRF

Recyclables

Recyclables

Non-recycled Waste

3. Commingled Recyclables MRF

2. Processing Sorted Recyclables



0. Yard Waste Collection

12. Wet/Dry (recyclables collected separately)

1. Mixed MSW

2. Commingled recyclables sorted at the point of collection

3. Pre-sorted Recyclables

4. Commingled Recyclables

5. Co-collection in single compartment truck

6. Co-collection in separate compartments

7. Mixed waste after removal of recyclables

8. Recyclables Drop-off

11. Wet/Dry (recyclables in dry)

Manufacturing Process

Mixed Waste Composting

Broken Glass

Recyclables

Non-recycled Waste

Non-recycled Waste

Recyclables

Recyclables

Residual

EnhancedBioreactor

Residual

Solid Waste Management Life-Cycle Inventory Model

A computer model to assist in decision makingQuantitative information to screen waste management alternatives

• cost, energy consumption, emissionsCompare many alternatives

• Identify an optimal solution• Model existing waste management system

Perform sensitivity analysis on uncertain model inputsThe person making a decision will still have to consider “unmodeled” factors

Modeling Solid Waste Management System in Delaware

New Castle County Urban64% of the state population

Kent CountySuburban to rural 16% of the state population

Sussex CountySuburban to rural20% of the state population

Modeling Approach

Each county was modeled separatelyRepresent individual facilities by countyUnique travel distancesMore realistic

ChallengesAppropriate combination of county-specific strategies to obtain appropriate statewide strategies

Data Collection: Waste Generation and Composition

Franklin Report for Delaware (2002)Waste generation

SCS Report (1997)Yard waste

EPA’s Waste Characterization Report: 2000 Update (2002)Wastes mapped into 42 categoriesGeneration vs. Disposal

Recycling Participation

Drop Off: Capture rates calculated from amount of material recycled (Franklin)

20% of MSW generated is recovered by Recycle Delaware Program

Curbside: recovery rate is assumed to be 20% greater than the national average

Waste Collection and Disposal

Tonnage data provided by DSWAPrivate MSW haulers contacted for route data

travel times between stopstime from garage to first stop% of volume utilized

Where are we now?




Statewide SWM StrategiesAlternative SWM StrategiesUncertainty analysis

Base Scenario Development

Current practice in Delaware is represented in SWM-LCI modelThe resultant strategy will serve as a base case (20% diversion) to analyze and compare differences in alternative SWM strategiesThe mass flows through facilities are appropriately represented

New Castle County is divided into 2 residential sectors

• one served by the transfer station• one with direct haul to landfill

SWM Strategies

IV

LandfillCombustionYard Waste CompostingMixed Waste MRFCommingled MRFPre-sorted MRF

VIIIIIICurrentLeast-GHELeast-Cost

Waste Flow Breakdown by Unit Operations[current practice (base case)]

20 17.8

18.6

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

Residuals Collection

Pre-sorted Recycling

TransferMRF

Landfill

Diversion

% o

f Tot

al W

aste New Castle

Kent

Sussex

Cost Breakdown by Unit Operations[current practice (base case)]

-10

-5

0

5

10

15

20

25

30

35

40

45



TransferMRF

Landfill

Transportation

RemanufacturingTotal

Cos

t, $

M/y

r

New Castle

Kent

Sussex

• Costs per ton are higher in rural counties

Indicator Parameters for Environmental Emissions

-4.0

-3.5

-3.0

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

-70 -60 -50 -40 -30 -20 -10 0 10Greenhouse Gas Equivalents, Thousands Tons/yr

Emis

sion

s, M

illio

ns lb

s/yr

Particulate MatterNitrogen Oxides

Sulfur Oxides

GHE Breakdown by Unit Operations[current practice (base case)]

-10

-5

0

5

10

15

20

25



TransferMRF

Landfill

Transportation


Gre

enho

use

Equi

vale

nts

(GH

E), T

hous

ands

Ton

s/yr

New Castle

Kent

Sussex

• Recycling results in avoided emissions

Where are we now?





Least-Cost SWM Strategies with

- Curbside Recycling

- Yard waste composting

- Combustion

Future Facility Locations

A combustion facility is assumed to be located near the landfill in New Castle CountyYard waste composting facilities are assumed to be located on the border of the Kent and Sussex Counties and near the landfill in New Castle County A MRF is assumed to be located on the border of the Kent and Sussex Counties

Variation of Mass Flows and GHE with Diversion[curbside recycling in New Castle County]

• Commingled recyclables only collected in residential sector 2 in max case

• Up to 28% diversion, pre-sorted and mixed waste MRFsare utilized, curbside recycling thereafter

• Minimum GHE at max diversion

New Castle County

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

20.0 21.0 22.0 23.0 24.0 25.0 26.0 27.0 28.0 28.5 28.9% Diversion

% o

f Tot

al W

aste

0

5

10

15

20

25

Gre

enho

use

Gas

Equ

ival

ents

(G

HE)

, Tho

usan

ds T

ons/

yr

Mixed WasteMRFPresortedMRFCommingledMRFGHE

Variation of Cost and GHE with Diversion[curbside recycling in New Castle County]

New Castle County

35

40

45

50

55

60

65

0 5 10 15 20 25 30

% Diversion

Tota

l Cos

t, $

M/y

r

10

15

20

25

30

35

40

Gre

enho

use

Equi

vale

nts

(GH

E),

Thou

sand

s To

ns/y

r

Cost

GreenhouseEquivalents

• Cost escalates with implementation of curbside recycling at 28% diversion

Variation of Mass Flows & GHE with Diversion [curbside recycling + yard waste composting in New

Castle County]

New Castle County

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

20 23 25 28 30 32 35 35.10 35.15% Diversion

% o

f Tot

al W

aste

10

12

14

16

18

20

22

24

Gre

enho

use

Gas

Equ

ival

ents

(G

HE)

, Tho

usan

ds T

ons/

yrMixed Waste MRF Pre-sorted MRF Commingled MRFYard Waste Composting GHE

• Cost of mixed waste MRF < yard waste composting < curbside collection

• GHE does not decrease with implementation of composting in contrast to recycling

Variation of Cost & GHE with Diversion [curbside recycling + yard waste composting in New

Castle County]

New Castle County

0

10

20

30

40

50

60

70

0 5 10 15 20 25 30 35 40

% Diversion

Tota

l Cos

t, $

M/y

r

0

5

10

15

20

25

30

35

40

45

Gre

enho

use

Equa

ival

ents

(GHE

), Th

ousa

nds

Tons

/yr

Cost

GHE

• Steep increase in cost with implementation of curbside recycling

Variation of Mass Flows & GHE with Diversion [curbside recycling + yard waste composting + combustion

in New Castle County]

New Castle County

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

20 25 40 60 80 85 88 88.70 88.73

% Diversion

% o

f Tot

al W

aste

-80

-60

-40

-20

0

20

40

Gre

enho

use

Gas

Equ

ival

ents

(G

HE)

, Tho

usan

ds T

ons/

yr

Mixed Waste MRF Pre-sorted MRF Commingled MRFYard Waste Composting Combustion GHE

• Combustion is utilized to meet diversion constraint because it is estimated to be less expensive than alternatives

• Note partial implementation of combustion & utilization of a mixed waste MRF

• GHE increases near maximum due to composting

Variation of Cost & GHE with Diversion [curbside recycling + yard waste composting +

combustion in New Castle County]

New Castle County

0

10

20

30

40

50

60

70

80

90

0 10 20 30 40 50 60 70 80 90 100% Diversion

Tota

l Cos

t, $

M/y

r

-50

-40

-30

-20

-10

0

10

20

30

40

50

Gre

enho

use

Equi

vale

nts

(GHE

), Th

ousa

nds

Tons

/yr

Cost

GHE

• Cost and GHE increase near maximum case illustrate extremes of numerical solution

• Ash content of yard waste leads to use of composting

Comparison of Cost and Emissions

88.47%

-2.16E+05

7.02E+03

5.60E+07

3.39E+08

-1.37E+06

-1.94E+06

6.88E+04

-2.32E+06

-2.71E+06

1.92E+08

Recycling + Composting

+ Combustion

MAX

85.29%31.03%30%34.88%28.34%25%19%%Diversion

-1.69E+061.15E+071.24E+077.32E+061.17E+071.22E+071.37E+08lbs/yearCH4

-8.04E+042.53E+041.90E+043.06E+043.19E+043.40E+043.81E+05tons/yearGHE

-5.54E+08-5.71E+07-1.20E+087.06E+07-1.12E+07-6.42E+06-8.96E+07lbs/yearCO2-Fossil

9.68E+085.25E+085.79E+084.66E+085.21E+084.98E+081.78E+09lbs/yearCO2-Biomass

3.89E+05-2.21E+069.12E+05-1.40E+06-1.77E+06-9.05E+04-1.42E+06lbs/yearCO

-4.88E+06-2.35E+06-2.42E+06-2.01E+06-2.31E+06-2.15E+06-1.85E+06lbs/yearSOx

-1.24E+06-4.91E+05-3.79E+054.94E+05-3.37E+04-3.22E+05-3.80E+04lbs/yearNOx

-1.05E+06-2.36E+06-1.68E+06-2.24E+06-2.35E+06-2.25E+06-1.84E+06lbs/yearTotal PM

-5.24E+06-2.85E+06-1.72E+06-2.27E+06-2.68E+06-2.02E+06-8.84E+05MBTU/yearEnergy

1.45E+081.19E+089.89E+072.05E+081.62E+081.01E+089.80E+07$/yearCost

Combustion No

Combustion


+ Combustion


MAXRecycling

MAXRecyclingCurrent

Least-GHELeast-Cost

UnitsParameter

Variation of Waste Flows, Cost, & GHE with Diversion

[curbside recycling]New Castle County

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

20.0 21.0 22.0 23.0 24.0 25.0 26.0 27.0 28.0 28.5 28.9% Diversion

% o

f Tot

al W

aste

0

5

10

15

20

25

Gre

enho

use

Gas

Equ

ival

ents

(G

HE)

, Tho

usan

ds T

ons/

yr

Mixed WasteMRFPresortedMRFCommingledMRFGHE

• Similar use of mixed waste MRF which is cheaper• GHE increases with use of curbside collection in Sussex County• GHE decrease by 50% in New Castle County, compared to only a 10%

decrease in Sussex County

Sussex County

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

19.0 20.0 21.0 22.0 23.0 24.0 25.0 26.0 27.0 27.5% Diversion

% o

f Tot

al W

aste

8

9

10

11

12

13

Gre

enho

use

Gas

Equ

ival

ents

(G

HE)

, Tho

usan

ds T

ons/

yr

Mixed Waste MRF Presorted MRF Commingled MRF GHE

New Castle County

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

20 23 25 28 30 32 35 35.10 35.15% Diversion

% o

f Tot

al W

aste

10

12

14

16

18

20

22

24

Gre

enho

use

Gas

Equ

ival

ents

(G

HE)

, Tho

usan

ds T

ons/

yr

Mixed Waste MRF Pre-sorted MRF Commingled MRFYard Waste Composting GHE

Sussex County

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

19 20 22 25 27 30 31 32 33 34 34.5

% Diversion%

of T

otal

Was

te

4

5

6

7

8

9

10

11

12

13

Gre

enho

use

Gas

Equ

ival

ents

(GH

E), T

hous

ands

Ton

s/yr

Mixed Waste MRF Pre-sorted MRF Commingled MRF

Yard Waste Composting GHE

• Similar use of mixed waste MRF, curbside recycling, yard waste composting• Utilization of composting stabilizes the emissions in New Castle County

scenarios, and increases emissions in Sussex County


[curbside recycling + yard waste composting]


[curbside recycling + yard waste composting + combustion]New Castle County

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

20 25 40 60 80 85 88 88.70 88.73

% Diversion

% o

f Tot

al W

aste

-80

-60

-40

-20

0

20

40

Gre

enho

use

Gas

Equ

ival

ents

(G

HE)

, Tho

usan

ds T

ons/

yr


Sussex Co

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

19 20 30 40 60 80 85 87 88

% Diversion

% o

f Tot

al W

aste

-8

-6

-4

-2

0

2

4

6

8

10

Gre

enho

use

Gas

Equ

ival

ents

(G

HE)

, Tho

usan

ds T

ons/

yr


• In Sussex County, a mixed waste MRF is utilized upstream of combustion to reduce transport costs

• Composting and curbside recycling only used near maximum diversion with resultant increases in GHE emissions

Where are we now?





Least-GHE SWM Strategies with Curbside Recycling + Yard Waste Composting + Combustion

Sussex County

-

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

Base MinGHE%

of T

otal

Was

te0

2

4

6

8

10

12

14

Gre

enho

use

Equi

vale

nts

(GH

E)Th

ousa

nds

Tons

/yr

Mixed Waste MRF Presorted MRF Commingled MRF GHE

Variation of Waste Flows & GHE with Cost While Minimizing GHE

[curbside recycling + yard waste composting]

• Increasing Cost constraint• New Castle: Drop-off<mixed waste MRF<commingled

recycling<composting• Sussex: only 2 cases due to 5% difference in cost between base case

and min GHE

-

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

Base 40 40 45 50 55 MinGHE

Total Cost, $ M/yr

% o

f Tot

al W

aste

0

5

10

15

20

25

Gre

enho

use

Equi

vale

nts

(GH

E), T

hous

ands

Tons

/yr

Mixed Waste MRF Presorted MRF Commingled MRF

Yard Waste Composting GHE

Variation of Waste Flows & GHE with Cost While Minimizing GHE

[curbside recycling + yard waste composting + combustion]New Castle County

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

39.67 40 45 50 55 60 65 70 MinGHE

Total Cost, $M/yr

% o

f Tot

al W

aste

-70

-60

-50

-40

-30

-20

-10

0

10

20

Gre

enho

use

Equi

vale

nts

(GHE

), Th

ousa

nds

Tons

/yr

Mixed Waste MRF Presorted MRF Commingled MRFCombustion GHE

Sussex County

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

38 39 40 41 42 43 44 MinGHETotal Cost, $M/yr

% o

f Tot

al W

aste

-12

-10

-8

-6

-4

-2

0

Gre

enho

use

Equ

ival

ents

(GHE

), Th

ousa

nds

Tons

/yr

Mixed Waste MRF Presorted MRF Commingled MRFCombustion GHE

• Increasing Cost constraint• Combustion most effective but a mixed waste MRF utilized upstream in

Sussex County• GHE levels off prior to min GHE scenario

Comparison of Cost and Emissions

88.47%

-2.16E+05

7.02E+03

5.60E+07

3.39E+08

-1.37E+06

-1.94E+06

6.88E+04

-2.32E+06

-2.71E+06

1.92E+08


+ Combustion

MAX

85.29%31.03%30%34.88%28.34%25%19%%Diversion

-1.69E+061.15E+071.24E+077.32E+061.17E+071.22E+071.37E+08lbs/yearCH4

-8.04E+042.53E+041.90E+043.06E+043.19E+043.40E+043.81E+05tons/yearGHE

-5.54E+08-5.71E+07-1.20E+087.06E+07-1.12E+07-6.42E+06-8.96E+07lbs/yearCO2-Fossil

9.68E+085.25E+085.79E+084.66E+085.21E+084.98E+081.78E+09lbs/yearCO2-Biomass

3.89E+05-2.21E+069.12E+05-1.40E+06-1.77E+06-9.05E+04-1.42E+06lbs/yearCO

-4.88E+06-2.35E+06-2.42E+06-2.01E+06-2.31E+06-2.15E+06-1.85E+06lbs/yearSOx

-1.24E+06-4.91E+05-3.79E+054.94E+05-3.37E+04-3.22E+05-3.80E+04lbs/yearNOx

-1.05E+06-2.36E+06-1.68E+06-2.24E+06-2.35E+06-2.25E+06-1.84E+06lbs/yearTotal PM

-5.24E+06-2.85E+06-1.72E+06-2.27E+06-2.68E+06-2.02E+06-8.84E+05MBTU/yearEnergy

1.45E+081.19E+089.89E+072.05E+081.62E+081.01E+089.80E+07$/yearCost

Combustion No

Combustion


+ Combustion


MAXRecycling

MAXRecyclingCurrent

Least-GHELeast-Cost

UnitsParameter

Observations from County-Wide Summary

The least-cost and least GHE solutions vary by countyUse of a mixed waste MRF upstream of combustionGHE from curbside recyclables collection in Sussex County

Non-uniform utilization of curbside collection, combustion subject to a cost constraintModel led to counter-intuitive results

MRF upstream of combustionEffectiveness of yard waste composting influenced by transport distance

Model can be rerun with alternate assumptions

Where are we now?


Least-cost scenarios• Combinations of Curbside Recycling, Yard

Waste Composting and CombustionConsideration of Environmental Emissions


Procedure to Identify Statewide SWM Strategies

SWM strategies are generated for each countyCombinations of these strategies are explored to identify

Cost-effective diversion strategies GHE-minimizing strategies at different costs

Identify the Cost-effective 30% Statewide Diversion Strategy?

……………………

……………………

……………………

100,072,350 35,145,802 20,485,900 44,440,648 33.3%20%20%40%

98,877,21435,145,802 20,485,900 43,245,513 30.0%20%20%35%

99,169,597 35,145,802 20,778,283 43,245,513 30.7%20%25%35%

99,256,197 35,524,785 20,485,900 43,245,513 30.9%25%20%35%

99,169,597 35,145,802 20,778,283 43,245,513 30.7%20%25%35%

99,258,166 35,524,785 21,683,004 42,050,377 30.5%25%40%30%

99,403,794 36,282,751 21,070,666 42,050,377 30.9%35%30%30%

99,317,194 35,903,768 21,363,049 42,050,377 30.7%30%35%30%

99,024,81135,903,768 21,070,666 42,050,377 30.0%30%30%30%

TotalSussexKentNew CastleState-wideSussexKentNew Castle

Cost [$/yr]DIVERSION

For each county approximately 17 SWM strategies exist (20 – 88% diversion):17 x 17 x 17 = 4,913 combinations should be analyzed for minimum cost…

Uniform diversion is not least cost case

Least-Cost 30% Statewide Diversion

Waste Flows in Cost-effective 30% Statewide Diversion Strategy

[curbside recycling + yard waste composting + combustion]

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

Mixed Waste MRF

Pre-sorted MRF

Commingled MRFTransfer

Yard Waste Composting

Combustion

Landfill

Diversion

% o

f Tot

al W

aste

New Castle

Kent

Sussex

• Minimize cost subject to a diversion constraint

• Analysis similar to county specific analyses

• Combustion used subject to cost constraint

• Mixed waste MRF used in rural counties

0

10

20

30

40

50

60

70

80

90

100

20 25 30 35 40 45 50 55 60 65 70 75 80 85 87 88 88.5

State-wide Diversion Rate, %

Cou

nty-

wid

e D

iver

sion

Rat

e, %

New Castle

Kent

Sussex

County-Specific Contribution to Statewide Diversion [curbside recycling + yard waste composting + combustion]

• The statewide optimum diversion strategy varies by county

• Between 50 and 70% diversion, all increases occur in New Castle County due to lower transport cost

Cost Breakdown in Cost-effective 30% Statewide Diversion Strategy


-10

0

10

20

30

40

50

Mixed Waste MRF

Pre-sorted MRF



Combustion

Landfill

Transportation


Tota

l Cos

t, $

Mill

ion/

yr

New Castle

Kent

Sussex

GHE Breakdown in Cost-effective 30% Statewide Diversion Strategy


-20

-15

-10

-5

0

5

10

15

20

25

Mixed Waste MRF

Pre-sorted MRF



Combustion

Landfill

Transportation


Gre

enho

use

Equi

vale

nts,

Tho

usan

ds to

ns/y

r

New Castle

Kent

Sussex

Variation of Waste Flows in Cost-effective 30% Statewide Diversion Strategy


0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

Mixed Waste MRF

Presorted MRF


Composting

CombustionLandfill

% o

f Tot

al W

aste

20%40%60%80%88%88.47%-"Max"

• Composting and curbside recycling only utilized near maximum diversion when combustion is enabled

Variation of Cost & GHE with Diversion in Cost-effective 30% Statewide Diversion Strategy


95

115

135

155

175

195

215

20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95

State-wide Diversion, %

Tota

l Cos

t, $M

illio

ns/y

r

-60-50-40-30-20-1001020304050

Gre

enho

use

Gas

Equ

ival

ents

, Th

ousa

nds

tons

/yr

Cost

GHE

• GHE increases at the extreme due to implementation of composting and curbside recycling to meet diversion constraint

Waste Flows in GHE-minimizing Strategies [curbside recycling + yard waste composting + combustion]

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Mixed Waste MRF

Presorted MRF


Composting

CombustionLandfill

% o

f Tot

al W

aste

$98.6M/yr - Base$100M/yr$110M/yr$120M/yr$130M/yr$140M/yr$145M/yr-Least GHE

• Combustion increases as the cost constraint is relaxed

• Yard waste never utilized as no GHE offset

• Curbside collection only used near min-GHE scenario

Tradeoff Between GHE and Cost (using GHE-minimizing scenarios)


-100

-80

-60

-40

-20

0

20

40

90 100 110 120 130 140 150

Total Cost, $M/yr

Gre

enho

use

Equi

vale

nts

(GHE

), Th

ousa

nds

Tons

/yr

0

10

20

30

40

50

60

70

80

Coun

ty-w

ide

Cost

, $M

/yr

GHE New Castle Kent Sussex

• Minimize GHE at increasing cost constraint

• No GHE benefit at increasing cost near minimum GHE

Observations from Statewide Analyses

The optimal statewide strategy is a combination of three unique SWM alternatives that are county-specific

a uniform statewide strategy will be sub-optimal

Where are we now?





Generating Alternative SWM Strategies

Optimal solution may not be appropriatepolitical feasibilitycapital intensivefacility siting…

Generate alternatives that maximize differences in unit operations & waste flow choices in SWM strategies

Cost-effective 30% statewide diversion strategy includes:

• cost-effective 35% diversion from New Castle

Cost: $43.2 M/yr $48 M/yr

• cost-effective 20% diversion from Kent

Cost: $20.2 M/yr $22.5 M/yr

• cost-effective 20% diversion from Sussex

Cost: $34.6 M/yr $38.7 M/yr

Generating Alternative Strategies

relax the cost

relax the cost

relax the cost

Waste Flows for Alternative SWM Strategies to Achieve 30% Statewide Diversion

13032511801780564tons/yrCombustion

303030%Diversion

12496131150tons/yrYard Waste Composting

574574310tons/yrCommingled MRF

172903271786696tons/yrPresorted MRF

1247728366573554tons/yrMixed Waste MRF

58297185719tons/yrPre-Sorted Transfer

53301989424394tons/yrMixed Waste Transfer

NC-Alt 2 + K-Alt 2 + S-Alt2

NC-Alt 1 + K-Alt 2 + S-LCLeast-Cost

Three of 27 cases considered at each diversion level based on generation of 2 alternatives per county (33)

Cost & Emissions for Alternative SWM Strategies to Achieve 30% Statewide Diversion

303030%Diversion13,239,24412,838,60412,161,215lbs/yrCH4

12,62111,28018,761tons/yrGHE-185,463,540-186,878,075-117,803,444lbs/yrCO2-fossil654,434,958650,697,534585,195,295lbs/yrCO2-biomass1,522,6361,077,938418,973lbs/yrCO-2,372,025-2,482,903-2,584,434lbs/yrSOx-222,019-265,041-560,727lbs/yrNOx-736,587-942,806-1,013,081lbs/yrTotal PM

-1,776,187-1,894,368-2,022,063MBTU/yearEnergy 105,105,000108,504,00098,060,000$/yearCost

NC-Alt 2 + K-Alt 2 + S-Alt2

NC-Alt 1 + K-Alt 2 + S-LCLeast-Cost

The alternatives perform differently with respect to cost and emissions

Observations from MGA Analysis

The procedure illustrated here could be applied to scenarios for which further study is desired

Select alternatives with favorable traits

Where are we now?





Consideration of Cost and Environmental Emissions Under Conditions of

Uncertainty

ObjectivesIntegrate uncertainty propagation proceduresCharacterize and compare uncertainty in cost and LCI emissions estimates

Uncertain Parameters

Collection Process:travel time between route and facility, number of houses per stop, loading time at one service stop, fuel usage rate

Combustion Processheat rate (kcal input/kWh)

Material Recovery Facilitybaler electricity usage rate

Landfill Processwaste density, gas collection efficiency, decay rate, extent of methane oxidation

Remanufacturing LCI ModelEmissions from raw and/or recycled material production such as ferrous, aluminum

Illustrative Results

The procedure was applied to the cost-effective 30% statewide diversion caseThe least-cost and two alternatives were analyzed

Uncertainty in Cost of Strategies for 30% Statewide Diversion


0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

70 80 90 100 110 120

Cost, $ Million/year

Prob

abili

ty

Base Case Least-cost with 30% Diversion Alternative 30% Diversion

$98M

$99M$109M

Uncertainty in GHE of Strategies for 30% Statewide Diversion


0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

10 15 20 25 30 35 40 45

Greenhouse Gas Equivalents, Thousand Tons/year

Pro

babi

lity

Base Case Least-cost with 30% Diversion Alternative 30% Diversion

43,00019,00029,000

Summary

Developed new procedures to use the model for a complex statewide analysisDemonstrated modeling to generate alternatives and uncertainty analysisQuantified tradeoffs among cost, diversion, emissionsProvided counter-intuitive and creative results

The Answer Is ……

Humans must still make decisionsConsider combustion, mixed waste MRFCan we vary solid waste management by county, or even neighborhood?• Use model to document cost implications of

this decisionWhat are the appropriate cost and emissions targets?

Going Forward

Identify a narrow set of favorable alternatives for further exploration

Model could be constrained to utilize favorable traits of multiple alternatives Consider locations of hypothetical new facilitiesDetailed engineering analysis

Acknowledgements

Delaware Solid Waste Authority

the application of life-cycle analysis to integrated solid ... · the application of life-cycle...

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