Week 10 pt2

Question 1

Life Cycle Assessment (LCA)

Answer 1

Is a tool to help decision-makers compare all major environmental impacts (characterise the environ. trade-offs), and hence select the product/process that results in the least impact to the environment.

Can be used for the Planning in EMSs.

Question 2

Why LCA?

Answer 2

Systematic and wholistic evaluation of environmental consequences

Can be quantitative (more rigorous) or qualitative

Optimising existing processes at each step, i.e., relates environmental impact to a function in a process.

Helping decision-making in selecting process/product alternatives.

Helping to avoid shifting environ. problems from one place to another

Question 3

Overview of LCA Procedure

Answer 3

1. Choose scope, boundary and functional unit
2. Inventory all resources, i.e., Mass & Energy balances!
3. LCA Impact Assessment
   Classification of impacts
   Characterisation of impacts
   Valuation
4. Interpretation/Improvement Analysis

Question 4

Scoping

Answer 4

Defines and describes product/process.
Establishes context where the assessment is to be made.
Identifies the boundaries and environ. effects to be reviewed for the assessment.
Provides background information, details methodological choices, and lays out report format

Scope includes
* Product system
* Functions of systems
* Functional unit
* System boundary
* Allocation procedures
* Impact categories, assessment method and interpretation type

Question 5

Inventory

Answer 5

Mass & Energy balances for process emissions
Quality of data
Can be a very big task
Subjectivity can be a problem

Question 6

Impact Assessment-Classification

Answer 6

Classify process inputs and outputs into impact categories, e.g., Carcinogenicity, Toxicity, Impact on ozone layer, Acid rain
Greenhouse effect enhancement

Question 7

Impact Assessment- Characterisation

Answer 7

Inventory value of each item multiplied by potency factor.

Potency factor depends on nature of item e.g., molecular weight, other chemical properties;

Effect scores obtained by adding results within an impact category…e.g., all the acidic items in the acidification category;

The effect scores for each class are then normalised against the contributions to that effect within a specified region, e.g., Australia.

Question 8

Impact Assessment- Valuation

Answer 8

Categories have different degree of impact on environment, so weight the results to reflect this and so identify major impacts

Environ impact of a category may vary with location, climate, conditions etc….i.e., weighting factors may be different according to situation

May be subjective

Question 9

Interpretation/Improvement Analysis

Answer 9

Identify parts of process needing attention….alternative preferable, otherwise implement pollution abatement…and can determine best type of that via LCA

Question 10

Issues/limitations re LCA

Answer 10

System boundary choice depends on availability
of: Inventory data, Resources, Time
General uncertainties in methodology
Potency factor availability
Temporal and spatial aggregation
Subjectivity of valuation
Hence may use streamlined version of LCA

Question 11

Streamlined LCAs

Answer 11

Used to identify most important parts to study.
Basis for selection:
Literature
Ignore components <1% product weight
Energy use
Toxicity
Economic value

Question 12

Qualitative LCAs

Answer 12

H,M,L…but equivalence issues over whole LCA
Semi-quantitative system, 1-4, and calculate
single score….good for comparisons
Can use these for potency factors…
Good for design phase where may have
insufficient quantitative data

Question 13

Eco-innovation Compass

Answer 13

Dow and World Council for Business Sustainability…options for new products/processes
Compass has 7 points: Service, Durability, Re-use, Mass, Energy, Safety, Resource Use
Allows trade-off b/w alternatives