Life Cycle Assessment LCA - University of...

Introductional lecture

Laboratory for Heat and Power

Life Cycle Assessment – LCA

Agenda

Life Cycle Assessment 2

What is LCA and how to use it?

How to approach LCA

1. Goal and scope

2. Inventory analysis

3. Impact assessment

4. Analysis and interpretation

Examples:

• Plastic bags

• CO2 emissions of vehicles

• 3 kW UPS system with PEM fuel cell

LCA – what is and how it is defined?

3

Life Cycle Assessment, as defined by the ISO 14040 and ISO 14044 is the compiling and

evaluation of the inputs and outputs and the potential environmental impacts of a

product system during a product’s lifetime

ISO 14040 introduction in LCA,

definition and background

ISO 14044 describes the procedure of

making LCA model

Life Cycle Assessment

LCA – how is structured?

4 Life Cycle Assessment

LCA – some historical overview

5

before

• Energy analysis in companies in energy intensity industry goal is to reduce costs of energy consumption and risk management linked to energy supply;

1969

• The Coca-Cola USA – first case

• Goal environmental impact of different packing - superiority of plastic packing

1984

• Swiss federal laboratory initiation;

• Necessarily of lining up of LCA methodology and definition of basic standards and guidelines

90s

• SETAC (Society of Environmental Toxicology and Chemistry) organization establishment

• Basic material database and first eco-labels for mass production products

till1996

• Under EcoInvent – Swiss center for life cycle basic databases definition of materials and processes from main industrial and economic branch

od 1997

• ISO standards 14040–14044 list exact definitions for LCA terminology, methods, processes, environmental declarations, management with natural resources, measurements, etc.


LCA – phases and use

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1. Definition of goal and scope

1. Definition of goal and scope

2. Inventory analysis 2. Inventory analysis

3. Impact assessment 3. Impact assessment

4. I

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LCA Framework Direct use

• Research and

improvement of

products/processes

• Strategic planning

• Policy

• Marketing

• Othr.


LCA – steps

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1. • GOAL of LCA

2. • SCOPE of LCA

3.

• Life Cycle Inventory (LCI) - energy and mass balance and environmental impacts

4.

• LCIA: Life cycle Inventory Assessment – Basic Impact categories / Impact methodology

5. • Interpretation / Analysis and reporting

6. • Critical review (optional)


1. Goal and the Scope GOAL

• The use of LCA (marketing, product research, product improvement, etc.) • The purpose: with purpose the scope is defined; • Audience: public, shareholders, executives, engineers, consumers, etc. • Usage for comparative analysis for publication of results critical review is obligatory;

SCOPE

During the scope definition the product or process system under study is characterized, all assumptions are detailed and the methodology used to set up the product system is defined. The following factors require definition before the LCA is done: • Function of the product • Functional unit • Reference flow • Description of the system • System boundaries • Allocation procedures • Impact categories and the impact assessment method • Data requirements • Data assumptions • Limitations • Data quality requirements • Peer review • Reporting type

8

Descriptions Descriptions


Scope: purpose and functional unit

Functionality of the product

• If different product are lined up, there functionality have to be exactly defined.

EXAMPLE: Pen

Purpose: writing/drawing

Functional unit: draw of line, 1 mm thick in 5 km long and lasts 10 years

Reference flow: is the number of pens that complete the purpose defined with functional

unit:

1 pen of manufacturer A

1,2 pen of manufacturer B

9 Life Cycle Assessment

Scope: Boundary conditions (the case of paper clip)

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Cut-off criteria: Which materials are included in the study (according to mass, environment impacts, etc.)

By mass: usually all materials are included that represent more than 5 % of overall mass;

… by energy, market value, etc.

• From cradle to grave

• From cradle to gate

• From gate to gate

• From gate to grave


Scope: Allocation

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In many processes more than one product is produced. In such a case all inputs and outputs of the

process have to be allocated to the different products. The allocation to different products can be

done according to one of the rules defined below

• by mass: proportional to mass;

• by heating value: This allocation method is often used for production processes of fuels;

• By market value;

• By other rules;

ISO14044 ISO suggests that allocation should be avoided whenever possible. The ISO also suggests that allocation according to physical relationships such as product mass or heating value rather than using non-physical relationships between the products (for example the market price).

PRIMER: 0,9 kg

0,1 kg

Product A represents 90 % of mass, therefore 90 % of all impacts are allocated to product A – allocation by mass.

Instead of allocation we can use: • System expansion; • Substitution of material / process


Scope: Data quality

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Descriptions of data quality are important because the data quality has a

significant influence on the results of the LCA study. Data quality requirements

have to be determined at the beginning of the study.

• Data acquisition: Is the data measured, calculated or estimated? How much of the data

required is primary data (in %) and how much data is taken from literature and databases

(secondary data)?

• Time-reference: When was this data obtained and have there been any major changes since

the data collection that might affect the results?

• Geographical reference: For what country or region is this data relevant?

• Technology (Best Available Technology) – Is the secondary data from literature or databases

representative for state-of-the-art-technology or for older technology?

• Precision: Is the data a precise representation of the system?

• Completeness: Are any data missing? How are data gaps filled?

• Representivity, consistency, reproducibility: Is the data representative, consistent and can it

be reproduced?


2. Life Cycle Inventory - LCI table

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Data gathering and LCI table creation:

• Iterative process;

• Represents the revision of the process;

• Possible adaptation of goal/scope;

• The result is LCI table;

• Mainly mass and energy flows are included

The setting up of LCI table


Life Cycle Inventory: Data gathering

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The most time demanding process in LCA study. All data of materials and processes have to be

carefully listed:

Inflows

• energy inputs

• raw material inputs

• ancillary inputs

• other physical inputs

Products and co-products

Outflows

• wastes

• emissions to air, water and soil

• other environmental aspects


Calculation of LCI

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Before calculating the life cycle inventory, the following three steps should be completed:

• Data Validation - Validating the collected data is a continuous process. This can be done

with mass or energy balances as well as with a comparison to similar data. Also,

methods have to be in place to handle data gaps.

• Relating Data to Unit Processes - The data has to be related to unit processes

• Relating Data to Functional Unit - The data has to be related to the functional unit.

* In GaBi, the LCI of the whole system is generated automatically once a system of processes

is set up.


3. LCIA: Life Cycle Impact Assessment

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The Life Cycle Impact Assessment (LCIA) identifies and evaluates the amount and significance of the

potential environmental impacts arising from the LCI. Inputs and outputs are first assigned to impact

categories and their potential impacts quantified according to characterization factors.

Figure shows the conversion from emissions to impact potentials via classification and characterization.

classification and characterization

Required steps

• Classification

• characterization

Optional steps

• Normalization

• Grouping /Weighting


Impact Assessment Methods

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There are different methods that can be used to perform a Life Cycle Impact Assessment. In life

cycle impact assessment methods, such as TRACI or CML, two main approaches are used to

classify and characterize environmental impacts:

• TRACI** (Tool for Reduction of Chemical and Environmental Impacts): mid-point method

(problem oriented) - ZDA

• CML*: End point method (damage oriented) - EU * Centre of Environmental Studies, University of Leiden

**EPA: U.S. Environmental Protection Agency

EXAMPLE: ECOINDICATOR 95 metod

damage oriented METHOD

- Classification of flows in different impact categories

- Impact categories are also grouped to belong to end-point categories:

- damage to human health;

- damage to ecosystem quality;

- damage to resources;

The used end points are easier to interpret and to communicate.

The choice of impact categories and the choice of the impact assessment method should be

documented in the goal and scope definition


LCIA: Classification and Categorization (ex.: methane)

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All emissions that add to GWP are transformed into CO2 equivalent according to categorization factor. According to CML 2001 (Dec. 2007) methane has categorization factor of 25, that means it contributes 25 times more than CO2, when the 100 year window is taken into account. Calculate the GWP of 6 kg of methane.


4. Interpretation

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Two basic steps that are iterative:

I. Identification of significant issues

II. Evaluation


To identify the “significant issues” or data elements that contribute most

significantly to the results of both the LCI and LCIA for each product, process or

service. Can include:

• LCI elements: energy consumption, major material flows, wastes and emissions etc.

• Impact category indicators that are of special interest or whose amount is of concern

• Essential contributions of life cycle stages to LCI or LCIA results such as individual unit processes

or groups of processes (e.g., transportation, energy production)

The results can be presented in form of data lists,¸tables, bar diagrams or other

convenient forms. They can be structured according to the life cycle phases, different

processesd.


4. Interpretation

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Two basic steps that are iterative:


II. Evaluation

I. Evaluation

The following three methods should be used for the evaluation

a. Completeness check: In the completeness check, any missing or information

will be analyzed to see if the information is necessary to satisfy the goal and

scope of the study.

b. Sensitivity check: The sensitivity check determines how the results are

affected by uncertainties in the data, assumptions, allocation methods,

calculation procedures, etc..

c. Consistency check: The consistency of the used methods and the goal and

scope of the study is checked: data quality, system boundaries, data

symmetry of time period and region, allocation rules and impact assessment.


4. Interpretation: conclusions, report and guidelines

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The goal of the life cycle interpretation phase is to draw conclusions, identify

limitations and make recommendations for the intended audience of the LCA:

• Identify the significant issues;

• Evaluate the methodology and results for completeness, sensitivity and

consistency; and

• Draw preliminary conclusions and check that these are consistent with the

requirements of the goal and scope of the study


4. Interpretation: Report (reference document)

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1. Administrative Information a. Name and Address of LCA Practitioner (who conducted the LCA study)

b. Date of report

c. Other Contact Information or Release Information

2. Definition of Goal and Scope

3. Life Cycle Inventory Analysis (data collection, calculation procedures, LCI

table)

4. Life Cycle Impact Assessment (methodology, results)

5. Life Cycle Interpretation

a. Results

b. Assumptions and Limitations

c. Data Quality Assessment

6. Critical Review (internal and external) a. Name and Affiliation of Reviewers

b. Critical Review Reports

c. Responses to Recommendations


Life Cycle Assessment LCA - University of...

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