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)

Source: Frankl&Rubik, 1999 Important applications of LCA perceived by industries

Disposal Use Resources and materials Manufacture 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)

Paper vs. Plastic Grocery Sacks: Comparison of Three Studies Allen & Bakshan i Graedel & Allenby Ciambro ne PE 60,790 sacks Energy [M BTU] Air pollution [lb] Paper 30,395 sacks Energy [M BTU] Air pollution [lb]

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?

Structure of a Process-based LCA Model process sub-system1 process sub-system2

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

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... emissions product system boundary RESOURCESRESOURCES waste

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] -1 F

Data Sources in EIO-LCA (1997)

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 $20,000 Car: Engine $2500$2000$1200$800$10... Conferences Other Parts Steel Plastics $2500 Engine: $300$200$150$10... Electricity SteelAluminum

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 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’)