Life Cycle Assesment Flashcards
(34 cards)
Definition of Industrial Ecology
The study of material and energy flows through industrial systems.
Life Cycle Assessment (LCA) Basics
A systems methodology for compiling and evaluating information on materials and energy as they flow through a product or service manufacturing chain.
2 main reasons for LCA to be carried out.
- To analyze all the steps in a product chain and see which use the greatest amount of energy and materials or produce the most waste
- To enable comparisons among alternative products or supply chains and to see which one create the least environmental impact
4 general stages of the product or service chain
- Acquisition of materials
- Manufacturing, refining, and fabrication
- Use by consumers
- End-of-life disposition
Characteristic Terminologies
Cradle-to-grave
includes the entire material/energy cycle of the
product/material, but excludes recycling/reuse.
Characteristic Terminologies
Cradle-to-cradle
includes the entire material cycle, including recycling/reuse.
Characteristic Terminologies
Cradle-to-gate
includes material acquisition, manufacturing/refining/fabrication (factory gate), but excludes product uses and end-of-life.
Characteristic Terminologies
Embodied energy
A cradle-to-gate analysis of the life cycle energy of a product, inclusive of the latent energy in the materials, the energy used during material acquisition, and the energy used in manufacturing intermediate and final products.
Characteristic Terminologies
Gate-to-gate
a partial LCA looking at a single added process or material in the product chain.
Characteristic Terminologies
Well-to-wheel
a special type of LCA involving the application of fuel cycles to transportation vehicles.
4 steps for conducting Life Cycle Analyses (LCAs)
- Scoping
- Inventory
- Impact Assessment
- Interpretation
Definition of scoping
The boundaries of the system are defined, where the data quantity, quality, and sources are specified, and where any assumptions that underlie the LCA are stated.
Inventory analysis
The inventory analysis step involves the collection of information on the use of energy and various materials used to make a product or service at each part of the manufacturing process.
Inventory Analysis
for product have been produced for a long time, the data are readily available. What about newer product?
for newer products that are either under development or under patent protection, data are often considered proprietary and are generally not shared in open sources.
Inventory Analysis
2 additional aspects that should be addressed during inventory analysis.
- the functional unit of comparison
- the allocation of inventory quantities among co-products or services.
Inventory Analysis
3 ways to allocate materials and energy among co-products
- Mass
- Volume
- Economic Value
Definition of Impact Assessment
The life cycle impact assessment (LCIA) takes the inventory data on material resources used, energy consumed, and wastes emitted by the system and **estimates potential impacts on the environment. **
When the interpretation step of LCA occurs ?
it occurs throughout the analysis
Interpretation of LCA
2 formal reasons for conducting an LCA
- identication of hot spots where material and/or energy use and waste emissions, both quantity and type, are greatest so that efforts can be focused on improving the product chain
- comparison of results between and among other LCAs in order to gain insight into the preferable product, service, process, or pathway.
Interpretation of LCA
how many cautions that apply to the interpretation of result
4 !
Interpretation of LCA
what are the cautions applied ?
- Assumptions
- Data Quality, Uncertainty, and Sensitivity
- Incommensurability
- Risk Evaluation and regulation
Interpretation of LCA
definition of assumptions
a variety of assumption must be
made in order to carry out the LCA.
Example; exclusion of elements of the study that clearly have no appreciable impact on the results or choosing one set of system boundaries over another.
Interpretation of LCA
what is data quality, uncertainty and sensitivity
a variety of data sources will be used in LCA. In some cases these may be from the full-scale operation of a process, in others the source is from a small scale or even laboratory scale,
in still other cases it may be necessary to simulate information from literature sources
Interpretation of LCA
what are the incommensurability
Sometimes LCA impact categories
are overlap in the sense that the same pollutant may contribute to more than one category
