Lecture 5 - LCA of WM (Chap 3.1-3.3)

Question 1

What is included in a Scope definition in LCA?

Answer 1

• Functional unit
  
  • -> Unitary: “management of 1 tonne of municipal solid waste”
  • -> Generation-based: “Management of the waste generated in Copenhagen municipality”
  • -> Input-based: “100 tonnes of waste entering a waste incineration plant”
  • -> Output-based: “Production of 500 kWh from a dedicated incineration plant for industrial waste”
• Approach to multifunctionality (attributional/consequential)
• Defining system boundaries and cut-offs
• Type, quality and sources of required data
• Review and reporting
• Identify critical review needs.

Question 2

Which life cycle stages is included in system boundary in LCA of waste management systems?

Answer 2

Only end-of-life (also waste generation in use stage needed as input).

Question 3

What 4 elements are in the simplified waste management chain?

Answer 3

• Sources (eg. households or industry)
• Collection (seperate or mixed)
• Treatment (eg. biological, mechanical, thermal, landfill)
• End-processing (eg. reprocessing, energy recovery)

Question 4

What are foreground systems (in LCA system boundaries)?

Answer 4

System for which we want to provide decision support regarding their development (comprises all waste management activities from waste generation through treatment and recovery of materials and/or energy, to the exchanged with the background systems)

Question 5

What are background systems (in LCA system boundaries)?

Answer 5

Systems which impact or govern the effects of decisions taken regarding foreground systems (economic activities and markets (e.g. energy production, material production) which exchange materials and energy (including the functional outputs) with the foreground system.)

Question 6

What is attributional LCI modelling?

Answer 6

Using average or generic data are typically used where the goods a services stem from a wide mix of producers or technologies. Also referred to as “accounting”, “book-keeping”, “retrospective” or “descriptive”.

Question 7

What is consequential LCI modelling?

Answer 7

Modelling aims at identifying the consequences that a decision in the foreground system has for other processes and system of the economy. Also called “change-orientated”, “effect-orientated”, “decision-based” and “market-based”. A key step is identification of marginal processes which responds to system changes.

Question 8

What are the 4 steps in LCIA?

Answer 8

• Classification
• Characterization
• Normalization - optional
• Weighting - optional

Question 9

Long-term landfill emissions are not directly comparable to the mostly instantaneous emissions from other processes. How is this issue solved?

Answer 9

• This problem is typically solved by integrating emissions over time and treating the integrated emissions as occurring at the same moment as other emissions.
• Requires that an adequate time frame for integration is chosen