industrial ecology – winter 2008 – session 11 – february 20 mfa methodology – all materials...

Industrial Ecology – Winter 2008 – Session 11 – February 20

MFA Methodology – All MaterialsMFA Methodology – All Materials

DomesticExtraction

DomesticProcessedOutput (DPO)(to Air, Landand Water)

DomesticHiddenFlows

DomesticHiddenFlows

Imports Exports

ForeignHiddenFlows

Air andWater

WaterVapor

Stocks

TMRTDODMI

Economic Processing

Domestic Environment

TMO

TMI


Input flows:

DomesticExtraction

DomesticHiddenFlows

Imports

ForeignHiddenFlows

TMRDMI

TMI

Direct Material Input = Domestic Extraction + Imports

Total Material Input = Direct Material Input + Domestic Hidden Flows

Total Material Requirement = Total Material Input + Foreign Hidden Flows

TMR

DMI

TMI



Output flows:


DomesticHiddenFlows

Exports

TDO


TMO

Total Domestic Output (TDO) = Domestic Processed Output + Domestic Hidden Flows

Domestic Processed Output (DPO) = Direct Material Input + Net Additions to Stock – Exports

Total Material Output (TMO) = Total Domestic Output + Exports

TDO

TMO

DPO



DomesticExtraction


DomesticHiddenFlows

DomesticHiddenFlows

Imports Exports

ForeignHiddenFlows

Air andWater

WaterVapor

Stocks

TMRTDODMI

Economic Processing


TMO

TMI



Input Flows (origin)Domestic extraction

Fossil fuels (coal, oil, etc.)Minerals (ores, gravel, etc.)Biomass (timber, cereals, etc.)

+ ImportsFossil fuels, Minerals, BiomassSemi-finished goodsFinal Goods

Direct material input (DMI)+ Unused domestic extraction

from mining/quarryingfrom biomass harvestsoil excavation

Total material input (TMI)+ Unused foreign extraction

from mining/quarryingfrom biomass harvestsoil excavation

Total material requirements (TMR)

Output Flows (destination)Emissions and wastes

Emissions to airWaste to landEmissions to water

+ Dissipative use of products(Fertilizer, manure, compost, seeds, paints, pesticides, etc.)

Domestic processed output to nature (DPO)+ Disposal of unused domestic extraction

from mining quarryingfrom biomass harvestsoil excavation

Total domestic output to nature (TDO)+ Exports

Fossil fuels, Minerals, BiomassSemi-finished goodsFinal Goods

Total material output (TMO)



Net Additions to stock (NAS): Infrastructure and buildings Machinery & durable goods etc.

Mass balance equation: Inflows – Outflows = Stock Change

Net Additions to Stock (NAS) = Domestic extraction + Imports – Direct Processed Output – Exports

Net Additions to Stock (NAS)DomesticExtraction


Imports Exports

Stocks



Material Flow Perspective of Pollution Prevention:Material Flow Perspective of Pollution Prevention:

If pollution is caused by material flows, its prevention is also a material issue:

There are essentially three ways to reduce or prevent pollution:

• Dematerialization (less material to achieve the same function)

• Substitution (different substance or material)

• Reuse & recycling (use material and value-added over and over)


Dematerialization examplesDematerialization examples

• Advanced High Strength Steels (AHSS) in automotive applications (25% weight reduction)

• Mass reduction of beverage containers

• Continuous casting technology in metals production

• Drip lines instead of sprinklers for irrigation

• Carsharing business models

• Spaceframe design concept

• Miniaturization in the electronics industry (e.g. precious metal content in consumer electronics)

Dematerialization typically has a natural economic driver and is also often done in conjunction with material substitution.


Dematerialization / Resource ProductivityDematerialization / Resource Productivity

Material flow indicator

GDP

Material flow indicator

Capita

Decoupling from economic growth

Decoupling from population growth

Criticism:• Trans-materialization• Re-materialization• Earths carrying capacity is absolute not relative

Generic environmental indicator

GDP per CapitaEnvironmental Kuznets Curve

Hypothesis: Dematerialization occurs naturally as nations get wealthier

3 main ways for dematerialization:• Increase primary resource productivity• Decrease material intensity of consumption • Increase resource productivity through reuse and recycling


Material substitution examplesMaterial substitution examples

• Steel versus aluminum versus plastics versus composites in automotive

• Steel versus concrete versus timber in construction

• Glass versus steel versus aluminum versus PET versus laminated cardboard in packaging

• MTBE instead of lead as oxygenate in automotive fuels

• Bio-based plastics versus petroleum-based plastics (e.g. polylactic acid)

• Lead-based solder versus lead-free solder (e.g. tin silver copper antimony alloy, tin copper selenium alloy, etc.)


Material substitutionMaterial substitution

Case study 1 – Lead-free solderCase study 1 – Lead-free solder

Background: Electronics industry consumes around 90 Kt pa of lead-based solder (60%Sn-40%Pb), 25-50% of which is process waste (recycling rate ?).

Issue: Toxicity of lead (EU ROHS Directive 2002/95/EC bans lead in EEE)

Substitute: Lead-free solder (e.g. the one announced by Sony in 1999: 93.4% tin, 2% silver, 4% bismuth, 0.5% copper and 0.1% germanium)

ADP (kg antimony eq.) HTP (kg 1,4-dichlorobenzene eq.)

Emission to soil

Lead 0.0135 3281

Tin 0.033 13

Silver 1.845 -

Bismuth 0.0731 -

Copper 0.00194 94

Germanium 0.00000147 -


Lead-free solder announced by Sony in1999: 93.4% Sn, 2% Ag, 4% Bi, 0.5% Cu and 0.1% Ge

New issues: • Production capacity for increased use of alloying materials: If all solder was based on Sony’s alloy, world production would increase as follows Sn +12%, Ag +11%, Bi +89%, Ge +103%• Bismuth by-product of mining other metal, especially lead, copper and tin• Depletion of some of the alloying metals

Alternative : Electrically conductive adhesives (polymer binder plus conductive filler)?

Current depletion time Depletion time with 100% Sony solder

Tin 27 20

Silver 16 14

Bismuth 30 16

Copper 35 35

Germanium 35 17


Case study 1 – Lead-free solderCase study 1 – Lead-free solder


Background: Production of plastics worldwide consumes around 270 MMT pa of fossil fuel, 120 MMT as feedstock and another 150 MMT as process energy.

Issues: • Depletion of fossil fuels • Additives (plasticizers, stabilizers, flame retardants, blowing agents)

• Lack of biodegradability (growing and persistent solid waste stream)

Substitute: Bio-based polymers (e.g. PLA or PHA)

Examples: • NatureWorks (Cargill Dow Polymers, USA) – packaging films, bottles, textile fibers based on polylactic acid from maize fermentation • GreenFill (GreenLight Products, UK) – loosefill packaging derived from wheat starch • Mater-Bi (Novamont, Italy) – films, tableware, nappies based on a copolymer of maize starch and polycaprolactone • (PotatoPak, UK) – supermarket display trays based on potato starch • (Rodenburg Polymers, NL) – packaging materials from potato starch • NatureFlex (Surface Specialities, UK) – cellulosic packaging films


Case study 2 – Bio-based plasticsCase study 2 – Bio-based plastics


American Society for Testing and Materials (ASTM) definition:“Biodegradable plastic: a degradable plastic in which the degradation results from the action of naturally occurring microorganisms such as bacteria, fungi and algae”.

The first compostable logo for cutlery went to Nat-Ur. The Biodegradable Products Institute’s (BPI) symbol demonstrates that the product meets the ASTM D6400 “Specifications for Compostable Plastics”.




European Standard for biodegradability is BS EN 13432 (2000):

• Biodegradation: over 90% compared with cellulose in 180 days under conditions of controlled composting using respirometric methods (ISO14855)

• Disintegration: over 90% in 30 months (ISO FDIS 16929)

• Ecotoxicity: test results from aquatic and terrestrial organisms (Daphnia magna, worm test, germination test) as for reference compost

• Absence of hazardous chemicals (included in the reference list)




In an LCA the cradle-to-gate GHG emissions of polyhydroxyalkanoate (PHA), a bio-polymer extracted from genetically modified corn, were compared to those of polyethylene (PE).

New issues: • The extraction process of PHA from corn stover is quite energy intensive.• If the extraction energy comes from fossil fuels, the cradle-to-gate GHG emissions of PHA are higher than those of PE.• Cradle-to-gate GHG emissions of PHA are lower than those of PE only if the stover is burned for energy generation, i.e. no fossil fuels are required for PHA extraction.

Material (fuel)

PHA (biomass)

PHA (natural gas)

PHA (coal)

PHA (oil)

LDPE HDPE

g CO2 eq / kg of resin

-4,000 3,800 5,400 5,000 2,800 2,200




Reuse and Recycling:Reuse and Recycling:

From Supply Chains to From Supply Chains to

Supply LoopsSupply Loops


Lee & Billington, for example, define a supply chain as […] a network of facilities that procure raw materials,

transform them into intermediary goods and then final products, and deliver the products to customers through a distribution system.What happens to the product after sale and deliveryis of no concern for supply chain managers

End-of-lifeproduct disposal

Product demand & use

Raw materials

mining

Primary materials

production

Component

manufacture

Finalproduct

assembly

Productsale anddelivery

Traditional supply chains end with the sale and delivery of the final product

From supply chains to supply loopsFrom supply chains to supply loops


Supply loops divert end-of-life products from landfill and reprocess these products, their components or their materials into secondary resources which replace primary resources in forward supply chains.



Raw materials

mining

Primary materials

production

Component

manufacture

Finalproduct

assembly


Componentre-

processing

Productre-

processing

Materialsre-

processing

Eol productcollection

& inspection




Raw materials

mining

Primary materials

production

Component

manufacture

Finalproduct

assembly


Componentre-

processing

Productre-

processing

Materialsre-

processing

Eol productcollection

& inspection

A supply loop is constrained when it is not able, for technical or economicreasons, to reprocess all targeted arising end-of-life products into secondaryoutput that is marketable a above-cost prices.

The reasons can be:• Limited collection of end-of-life products• Limited feasibility of reprocessing

• Limited market demand for the reprocessed secondary resources


Production DisposalUse

Reuse and recycling – Environmental benefitsReuse and recycling – Environmental benefits


1. Diversion of product or process waste from landfill or incineration

by collecting them for economic value recovery via reprocessing.

2. Generation of secondary resources from product or process waste

and displace primary resources, i.e. materials, components and products.

The environmental benefits from displacement can be significantly higher than the benefits from avoided landfill / incineration.

1. 2.


Supply Loops - Material Recycling - DefinitionsSupply Loops - Material Recycling - Definitions

Product manufacturing

Disposal

UseMaterial

Production

Material reprocessing

recycling input rate

recycling efficiency rate

eol recycling efficiency rate

Eol collection rate

Eol reprocessing yield

Oco

O

NcrOcrS nnoo

P

N

Ncn

oooo crO

Ocr

oo cO

Oc

oo

oo rOc

Ocr

P

S

NO

S


Materialsproduction


Materialsuse

is the recycling efficiency rate for each cycle

Question: How much recycled material do I get from m primary material?

Total amount of material (assuming unlimited recyclability) is

Summing this series gives

of which is secondary (recycled) material.

Overall recycling efficiency rate:

Supply Loops – Materials Recycling – Infinite CyclesSupply Loops – Materials Recycling – Infinite Cycles

Example:ρ = 0.66, m = 1kgM = 3kg1kg primary2kg secondary

1

...432 mmmmM

)1( mM

MS

)1()1( mmmS


ProductionEprod

CollectionEcoll

End-of-life disposalEdisp

ReprocessingErepro

UseEuse

Life cycle impact (of a chosen environmental impact category):

• Without recycling:

• With recycling:

Change in life cycle impact

Recycling reduces life cycle impact if

Supply Loops – Basic Environmental PerformanceSupply Loops – Basic Environmental Performance

R

R1R1

R

dispuseprodwithout EEEE

dispcollusereproprodwith ERREEREERE )1()1(

)( dispprodreprocollwithoutwith EEEEREEE

collreprodispprod EEEEE 0


Basic Environmental Performance – ExamplesBasic Environmental Performance – Examples


Material Primary Production (cradle-to-gate in

MJ/kg)

Secondary Production (cradle-

to-gate MJ/kg)

SavingsFactor

Steel 21.7 7.1 3

Aluminum 194.7 10.3 19

Copper ~100 20 – 30 3.3 - 5

Glass 12 7.2 1.7

PET 82.7 ? ?


Due Date of Assignment 3: Wednesday, 27 February:Due Date of Assignment 3: Wednesday, 27 February:

Reading for Friday, 22 February:Reading for Friday, 22 February:

Geyer & Jackson (2004) Supply loops and their constraints: The industrial ecology of reuse and recycling, Cal Man Rev 46(2), 55-73

Davis et al. (2007) Time-dependent MFA of iron and steel in the UK, Resources, Conservation & Recycling 51(2007), 118-140

(is posted on course website)

industrial ecology – winter 2008 – session 11 – february 20 mfa methodology – all materials...

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