1. Life Cycle Assessment (LCA)

2. Life Cycle Assessment (LCA)
Life Cycle Assessment is an environmental management tool. The International Organisation for Standardisation (ISO) defines LCA as
A compilation and evaluation of the inputs, outputs and potential environmental impacts of a product throughout its lifecycle

3. Life Cycle Assessment (LCA)
LCA considers the following stages in the life cycle of an activity
Extraction and processing of raw materials
Manufacturing
Transportation and distribution
Use, reuse and maintenance
Recycling
Final disposal

4. Life Cycle Assessment (LCA)
Primary Resources
Emissions & Waste
Extraction & Processing
Production
Use
Reuse/Recycle
Disposal

5. Life Cycle Assessment (LCA)
The LCA methodology is standardised by a series of ISO standards and includes the following phases
1. Goal and scope definition (ISO 14041)
2. Inventory Analysis (ISO 14041)
3. Impact Assessment (ISO 14042)
4. Interpretation (ISO 14043)

6. Goal and Scope Definition
The first phase of LCA includes definition of
The purpose of the study and its intended use
The system and system boundaries
The functional unit
Data quality, the assumptions and limitations of the study

7. Goal and Scope Definition
In full LCA studies, the system boundary is drawn to encompass all stages in the life cycle from extraction of raw materials to the final disposal. However, in some cases, the scope of the study will demand a different approach, where it is not appropriate to include all stages in the life cycle. This is usually the case with commodities, for instance, which can have a number of different uses so that it is not possible to follow their numerous life cycles after the production phase. The scope of such studies is from “cradle to gate”.

8. Goal and Scope Definition
One of the most important elements of an LCA study is a functional unit. The functional unit represents a quantitative measure of the output of products or services which the system delivers. In comparative LCA studies, it is crucial that the systems are compared on the basis of equivalent function, that is functional unit
Eg comparison of different beverage packaging should be based on their equivalent function which is to contain a certain amount of beverage. The functional unit is then defined as “the quantity of packaging necessary to contain the specified volume of beverage”.

9. Inventory Analysis
The purpose of the “Inventory Analysis” is to identify and quantify the environmental burdens in the life cycle of the activity under study. The burdens are defined by material and energy used in the system and emissions to air, liquid effluents and solid wastes discharged into the environment.
Inventory Analysis includes the following steps
Detailed definition of the system under study
Data collection
Allocation of environmental burdens in multiple-function systems
Quantification of the burdens

10. Life Cycle Inventory Analysis
Materials Acquisition
Formulation, processing and Manufacturing
Product Distribution
Product use
Recycle, products, components, materials
Waste Management
Inputs
Materials
Energy
Water
Air
Outputs
Principal Products
Coproducts
Water effluents
Airborne emissions
Solid Waste
Other Environmental
interactions

11. Life Cycle Inventory Analysis
Environment
System
Functional Outputs
Inputs
Emissions/Wastes
Subsystems

12. Life Cycle Inventory Analysis
Environmental burdens are then quantified for each subsystem according to the formula
Where bcj,i is burden j from activity i and xi is a mass or energy flow associated with that activity

13. Calculating Environmental Burdens & Impacts in LCA - Example
The system in this example has one functional output and each activity i from extraction of raw materials to final disposal generates a certain amount of CO2 and CH4.
Extraction
Production
Use
Disposal
CO2 = 0.2 kg/t
CH4 = 0.1 kg/t
x1 = 2t/tFU
CO2 = 0.3 kg/t
x2 = 1.5t/tFU
CO2 = 0.1kg/t
CH4 = 0.1kg/t
x3 = 1t/tFU
CH4 = 0.3kg/t
x4 = 0.5 t/tFU x1 x2 x3 x4 FU

14. Calculating Environmental Burdens & Impacts in LCA - Example
Using the Environmental Burdens equation the total environmental burdens per functional unit related to the emissions of CO2 and CH4 are therefore
BCO2 = ∑bcCO2 . xi = (0.2)2+(0.3)1.5+(0.1)1+(0.1)0.5 →BCO2 = 1.0 kg/tFU
BCH4 = ∑bcCH4 . xi = (0.1)2+(0.1)1.5+(0.1)1+(0.3)0.5 →BCH4 = 0.6 kg/tFU

15. Classification Factors for Selected Burdens

16. Calculating Environmental Burdens & Impacts in LCA - Example
EGWP = (ecCO2)BCO2 + (ecCH4)BCH2
= 1(1) + 21(0.6)
→ EGWP = 13.6 kg CO2 equiv / tFU

17. Impact Assessment The impacts most commonly considered in LCA are
Non-renewable resource depletion
Global warming
Ozone depletion
Acidification
Eutrophication
Photochemical oxidant formation
Human toxicity
Aquatic toxicity

18. Impact Assessment Characterisation
Involves the quantification of the impact of interest relative to a reference substance. In the example we examined we look at the Global Warming Potential of the Products life cycle relative to CO2 emissions. Takes place using the formula
eck,j represents the relative contribution of burden Bj to impact Ek

19. Interpretation
This phase is aimed at system improvements and innovation and it includes the following steps
Identification of major burdens and impacts
Identification of ‘hot spots’ in the life cycle
Sensitivity analysis
Evaluation of findings and recommendations

20. Interpretation Sensitivity Analysis
Indicates the level of reliability of the LCA
Data availability and reliability
Uncertainties
Data gaps