Using InputOutput Analysis for Life Cycle Assessment

1
Using Input-Output Analysis for Life Cycle
Assessment

• 12-090 Lecture 9
• Readings
• Industrial Ecology excerpt, Sullivan et al.,
  Maclean and Lave

2
Life Cycle Assessment

• An analysis of the environmental effect of
  materials taken out of the environment (inputs)
  and wastes released (outputs) for a product or
  service over its life

3
Components and Criteria of LCA

• Inventory analysis
• What are inputs and outputs at each life cycle
  stage
• Impact analysis
• What are the environmental impacts from the
  inputs and outputs
• Improvement analysis
• How can the design be changed to reduce impacts

4
Environmental Assessment Inputs (Resources)

• Raw materials
• E.g., minerals, ores (iron, copper, bauxite,
  zinc, lead, gold, silver, etc.), chemicals,
  fertilizers
• Energy
• E.g., electricity, petroleum (motor gasoline,
  kerosene, jet fuel, aviation fuel, etc.), natural
  gas, coal (bituminous, anthracite), nuclear fuel

5
Environmental Assessment Outputs (Emissions
and Wastes)

• Solid, liquid, gaseous
• Toxic emissions
• Greenhouse gas emissions (CO2, N2O, CH4, CFC-11,
  CFC-12)
• Conventional pollutants (CO, SO2, NOx,
  Particulates, VOCs)
• Hazardous wastes
• e.g., asbestos, mercury switches, lead-acid
  batteries
• Non-hazardous wastes

6
Data Sources in LCA

• Proprietary company data
• Consultants, labs, academia
• Public
• U.S. EPA data, e.g.,
  Toxics Release Inventory
  (TRI)
• Data sources and accuracy are often the biggest
  problems

7
Models of LCA

• Conventional LCA, developed by SETAC and EPA,
  based on process models
• Traditionally graphic interfaces to databases of
  data
• Economic input-output analysis-based LCA
  (EIO-LCA), developed by Carnegie Mellons Green
  Design Initiative

8
Economic Input-Output Analysis

• Developed by Wassily Leontief (Nobel Prize in
  1973)
• General interdependency model quantifies the
  interrelationships among sectors of an economic
  system
• Identifies direct indirect economic inputs
• Can be extended to environmental and energy
  analysis

9
Circularity Effects

• Circularity effects in the economy must be
  accounted for cars are made from steel, steel is
  made with iron ore, coal, steel machinery, etc.
  Iron ore and coal are mined using steel
  machinery, energy, etc...

product
emissions
10
The Boundary Issue

• Where to set the boundary of the LCA?
• Conventional LCA ideally include all
  processes, but at least the most important
  processes (these get added into a more complete
  model)
• In EIO-LCA, the boundary is by definition the
  entire economy, recognizing interrelationships
  among industrial sectors
• In EIO-LCA, the products described by a sector
  are representing an average product not a
  specific one

11
EIO-LCA Implementation

• Use the 498 x 498 input-output matrix of the U.S.
  economy
• Shows effects of production in US economy
• Augment with sector-level environmental impact
  coefficient matrices effect/ output from
  sector
• Sector or industry analysis, not product

12
Input-Output Visualization

• Production Recipe - 20,000 automobile

Engine
Conferences
Steel
. . .
Car
2500
2000
1000
1000
10
Other Parts
Plastics
13
Direct versus Indirect Effects

• Direct effects
• Inputs needed for final production of product
  (energy, water, etc.)
• Immediately associated with product (e.g.,
  emissions from the auto assembly plant)
• Indirect effects
• ALL inputs needed in supply chain, impacts from
  other stages
• Uncontrolled by product manufacturer (e.g.,
  emissions from suppliers plants)
• e.g. Metal, belts, wiring for engine
• e.g. Copper, plastic to produce wires

14
EIO-LCA Software

• Internet URL http//www.eiolca.net/
• First LCA tool completely free on Internet in
  full version
• Uses public data
• Quick, easy to use

15
Comparison of LCA Models

• Both conventional LCA and EIOLCA have merits
  and limitations
• Speed
• Accuracy
• Scope
• Availability
• Regardless, life-cycle assessment is an important
  and robust tool for pollution prevention and
  environmental decision-making