Life Cycle Assessment Scott Matthews Civil and Environmental Engineering Carnegie Mellon University
LCA patterns of use • More for larger firms than smaller. • More a tool for a pull strategy than for a push strategy. • Acceptance substantially vary among countries (more accepted by developed countries than developing countries). • LCA started to become a part of the regulatory system in Europe but not in the US.
Some results from the Survey by Frankel and Rubik (1999)
Important applications of LCA perceived by industries Source: Frankl&Rubik, 1999
Resources and materials Manufacture Disposal Use Example of process-flow diagram (aggregated): Source: Hauschild, 2003 Product system of a uniform (cloth)
Example of “required data” table (Inputs and outputs table - part) (source: International Aluminum Institute, 2003)
Identifying required data (cumulative input mass - part) (source: Suh, 2000)
Example of inventory result (part) (source: International Aluminum Institute, 2003)
In-Class Assignment • Suppose you need to choose a new copier for an office. In a small group: • Define appropriate goals and scope for a life cycle cost and environmental life cycle assessment. • Define appropriate environmental indicators (e.g. electricity or energy use). • Define major benefit or cost categories to consider • Develop a set of processes to be considered (i.e. inputs and outputs identified and estimated). • We will have reports from groups by end of period.
Example: Copier LCA • In GaBi demo, explore under Processes, Production, Materials, Metal • Look at steel (3 options) • Can also see plastic, etc options • Double click to see inputs/outputs • Generally shows normalized impacts for 1kg of output item (eg 1 kg of ABS plastic) • The data records refer to a process that requires many inputs, and produces 1 kg of ABS plastic (as well as many other outputs)
Complexity • We’ve been looking at fairly small, streamlined LCI problems • How does the method scale?
sub-system2 process process process process process process process process process process process process process process process process process process process process process sub-system1 Structure of a Process-based LCA Model
The Boundary Issue • Where to set the boundary of the LCA? • “Conventional” LCA: include all processes, but at least the most important processes if there are time and financial constraints • 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
RESOURCES waste system boundary 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
Economic Input-Output Life-Cycle Assessment (EIO-LCA)
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
EIO-LCA Implementation • Use the 498 x 498 input-output matrix of the U.S. economy from 1992 • 491 for 1997 • Augment with sector-level environmental impact coefficient matrices (R) [effect/$ output from sector] • Environmental impact calculation: E = R[I - D]-1F
Life Cycle Stages • At each stage, there are some inputs used and some outputs created that need to be identified • Example: automobile production • Direct: smoke from factory • Indirect: smoke from suppliers’ factories
I-O and Supply Chains Engine Steel Conferences . . . $20,000 Car: $2500 $2000 $1200 $800 $10 Other Parts Plastics Electricity . . . $2500 Engine: $300 $200 $150 $10 Steel Aluminum
Effects Specified • Direct • Inputs needed for final production of product (energy, water, etc.) • Indirect • ALL inputs needed in supply chain • e.g. Metal, belts, wiring for engine • e.g. Copper, plastic to produce wires • Calculation yields every $ input needed
EIO-LCA Software • Internet version http://www.eiolca.net/ • About 1 million users to date • About 1,500 registered users • update notices • other benefits • First LCA tool completely free on Internet in full version (not a ‘demo’)