Reuse and Recycling: From Supply Chains to Supply Loops

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Reuse and RecyclingFrom Supply Chains to Supply
Loops
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From supply chains to supply loops
Traditional supply chains end with the sale and
delivery of the final product
Raw materials mining
Primary materials production
Component manufacture
Final product assembly
Product sale and delivery
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.
Product demand use
End-of-life product disposal
What happens to the product after sale and
deliveryis of no concern for supply chain
managers
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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
Final product assembly
Product sale and delivery
Product demand use
Component re- processing
Product re- processing
Materials re- processing
End-of-life product disposal
Eol product collection inspection
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A supply loop is constrained when it is not able,
for technical or economic reasons, to reprocess
all targeted arising end-of-life products into
secondaryoutput that is marketable a above-cost
prices.
Raw materials mining
Primary materials production
Component manufacture
Final product assembly
Product sale and delivery
Product demand use
Component re- processing
Product re- processing
Materials re- processing
End-of-life product disposal
Eol product collection inspection

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

• Limited feasibility of reprocessing

• Limited market demand for the reprocessed
  secondary resources

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Supply Loops Environmental Benefits
2.
1.
Primaryproduction
Disposal
Use
Collection reprocessing

• Diversion of product or process waste from
  landfill or incineration by collecting them for
  economic value recovery via reprocessing.
• Generation of secondary resources from product
  or process waste and displacement of primary
  resources, i.e. materials, components products.

The environmental benefits from displacement are
frequently more significant than the benefits
from avoided landfill / incineration.
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Supply Loops - Material Recycling Definitions
Primary material production
Product manufacturing
Use
Disposal
Material reprocessing
Secondary output
eol recycling efficiency rate Eol collection
rate Eol reprocessing yield
Available secondary resource
Collected secondary resource
Available secondary resource
Secondary output
Collected secondary resource
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Supply Loops - Material Recycling - Definitions
Primary material production
Product manufacturing
Use
Disposal
Material reprocessing
eol recycling efficiency rate Eol collection
rate Eol reprocessing yield
Overall recycling input rate Overall
recycling efficiency rate
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Supply Loops Material Recycling Infinite
Cycles
Materialsproduction
End-of-life product disposal
Materials use
Collection recycling
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
Example ? 0.66, m 1kg M 3kg 1kg
primary 2kg secondary
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Supply Loops Environmental Performance 100
yield
Production Eprod
End-of-life disposal Edisp
Use Euse
Collection Ecoll
Reprocessing Erepro

• Life cycle impact (of a chosen environmental
  impact category)
• Without recycling
• With recycling
• Change in life cycle impact
• Recycling reduces life cycle impact if

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Supply Loops Environmental Performance
Limited yield
Production Eprod
Use Euse
End-of-life disposal Edisp
Collection Ecoll
Reprocessing Erepro

• Life cycle impact (of a chosen environmental
  impact category)
• Without recycling
• With recycling
• Change in life cycle impact
• Recycling reduces life cycle impact if

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Supply Loops Environmental Performance
Examples
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Case study Recycling and reuse of structural
steel sections in construction
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Case study Recycling and reuse of structural
steel sections in construction
Product life cycle
Use of buildings and other structures
BF Section production 28.5GJ / tonne
Fabrication of sections 4.8GJ / tonne
Use of sections in construction 2.0GJ / tonne
EAF Section production 10.8GJ / tonne
Re-fabrication of sections 4.8GJ / tonne
Section recovery via deconstruction 0.4GJ / tonne
Section recovery via demolition 0.4GJ / tonne
Landfill of sections 1.3GJ / tonne
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Case study Recycling and reuse of structural
steel sections in construction
Environmental evaluation of supply loops for
steel sections
Factor 2
Factor 5
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Energy savings of section reuse relative to
recyclingas a function of reuse rate R (starting
with 100 recycling, no reuse)
It seems that, since Ereuse lt Erecycle, reusing
more is better. However, Edecon and Erefab may
be increasing functions of r.
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Energy savings of section reuse relative to
recyclingas a function of reuse rate R (starting
with 100 recycling, no reuse)
It Ecoll and Erepro are increasing functions of
r,Ereuse will increase with increasing reuse
rate.
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Case study Reusing Components in Durable Goods
Model
Product demand use
Product manufacturing Eman
1-rc
1-c
rc
c
Eol product collection insp. Ecoll
End-of-life product disposal Edisp
Product remanufacturing Ereman
rc
(1-r)c

• Environmental impact
• Without reuse Eman Edisp
• With reuse (1-rc)Emanrc Ereman c Ecoll
  (1-rc) Edisp
• Change in environmental impact
• ?E rcEman rcEdisp - rcEreman - cEcoll
  gross reduction - additional
  impact
• c collection rate, r reuse yield, product between
  c and r is reuse rate rc

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Supply loop constraint Limited component
durability
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Supply loop constraint Limited component
durability
Example Average number of lives n 3
Collection rate c 0.1 Total collected
111 Total reused 110
1
Reuse yield r
Collection rate c
1
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Supply loop constraint Limited component
durability
Example Average number of lives n 3
Collection rate c 0.5 Total collected
875 Total reused 750
1
Reuse yield r
Collection rate c
1
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Supply loop constraint Limited component
durability
Example Average number of lives n 3
Collection rate c 0.9 Total collected
2439 Total reused 1710
1
Reuse yield r
Collection rate c
1
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Limited component durability impacts technical
feasibility of reuse
Reuse rate rc is now a non-linear function of
the collection rate c and the average number of
lives n
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Total environmental impact is a non-linear
function of the collection rate c
Beyond a certain collection rate environmental
impact starts to increase again.
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Conclusions
In supply loops the additional environmental
impacts ofcollection and reprocessing need to be
traded off against the saved environmental
impacts of primary production and disposal. In
constrained supply loops more is not always
better. Supply loops may haveenvironmentally
optimal collection rates anywhere between 0 and
100.

• In product systems with reuse the environmental
  impacts of the processes need to be assessed and
  managed in an integrated way withthe three basic
  supply loop constraints
• the access to end-of-life products
• the feasibility of the reprocessing
• and the market demand for the secondary resources

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Case study Iron and Steel in the UK

• Scope and system boundaries
• Document and analyze the iron steel flows of
  the UK from 1970-2000
• Calculate the current recycling rate
• Boundaries of the material stocks are the
  geographical borders of the UK
• Account for trade

• Process groups
• Production (integrated steelworks, EAF mills,
  foundries)
• Fabrication and manufacturing (component and
  product manufacturing)
• Use

• Material categories
• Iron ore
• Iron and steel scrap - Home scrap (generated
  at iron and steel foundries and mills) -
  Prompt or new scrap (generated during fabrication
  and manufacturing) - End-of-life or old scrap
  (generated when iron and steel containing goods
  leave the use phase)
• Iron and steel industry products (e.g. castings,
  ingots, billets, rods, bars, sections,
  plates, strip, sheet, etc.)
• Iron and steel contained in new final goods (
  of iron and steel in goods)

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Case study Recycling Rate of Iron and Steel in
the UK
Material and process flow model of the UK iron
and steel cycle
Trade
Trade
Trade
Iron steel products
Iron steel in new goods
Iron ore
Production
Use
Fabrication manufacturing
C
Iron steel scrap
TSG
Loss
Ex
Im
UK border
Trade
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Case study Recycling Rate of Iron and Steel in
the UK
Ex
Im
C
TSG
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Case study Recycling Rate of Iron and Steel in
the UK
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Case study Recycling Rate of Iron and Steel in
the UK
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Case study Recycling Rate of Iron and Steel in
the UK
I S in new final goods entering use in the UK
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Case study Recycling Rate of Iron and Steel in
the UK
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Case study Recycling Rate of Iron and Steel in
the UK
Total scrap generation versus actual scrap
consumption
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Case study Recycling Rate of Iron and Steel in
the UK
Results and sensitivity analysis