Life Cycle Assessment (LCA)

A Guide to Best Practice

Walter Klöpffer, Birgit Grahl

• Éditeur: Wiley-VCH
• Année: 2014
• ISBN:
  9783527655649
• Édition: 1
• Sujet: Scienze fisiche
• Sous-sujet: Chimica organica

This first hands-on guide to ISO-compliant Life Cycle Assessment (LCA) makes this powerful tool immediately accessible to both professionals and students. Following a general introduction on the philosophy and purpose of LCA, the reader is taken through all the stages of a complete LCA analysis, with each step exemplified by real-life data from a major LCA project on beverage packaging. Measures as carbon and water footprint, based on the most recent international standards and definitions, are addressed. Written by two pioneers of LCA, this practical volume is targeted at first-time LCA users but equally makes a much-valued reference for more experienced practitioners. From the content:
* Goal and Scope Definition
* Life Cycle Inventory Analysis
* Life Cycle Impact Assessment
* Interpretation, Reporting and Critical Review
* From LCA to Sustainability Assessment and more.

1
Introduction

To date life cycle assessment (LCA) is a method defined by the international standards ISO 14040 and 14044 to analyse environmental aspects and impacts of product systems. Therefore, the introduction of the methodology in Chapters 2–5 relates to these standards. As a prelude, the scope and development of the methodology are introduced here.

1.1 What Is Life Cycle Assessment (LCA)?

1.1.1 Definition and Limitations

In the introductory part of international standard ISO 14040¹ serving as a framework, LCA has been defined as follows:

LCA studies the environmental aspects and potential impacts throughout a product's life (i.e. cradle-to-grave) from raw material acquisition through production, use and disposal. The general categories of environmental impacts needing consideration include resource use, human health, and ecological consequences.

A similar definition of LCA was adopted as early as 1993 by the Society of Environmental Toxicology and Chemistry (SETAC)² in the ‘Code of Practice’.³

Similar definitions can also be found in the basic guidelines of⁴ DIN-NAGUS as well as in the ‘Nordic Guidelines’⁵ commissioned by Scandinavian Ministers of the Environment. Those deliberate limitations of LCA to analysis and interpretation of environmental impacts have the consequence that the method is restricted to only quantify⁶ the ecological aspect of sustainability (see Chapter 6). The exclusion of economical and social factors distinguishes LCA from product line analysis (PLA) (Produktlinienanalyse) and similar methods.⁷ This separation was made to avoid a method overload, being well aware that a decision, for example, in the development of sustainable products, cannot and must not neglect these factors.⁸

1.1.2 Life Cycle of a Product

The main idea of a cradle-to-grave analysis, that is, the life cycle of a product, is illustrated in a simplified manner in Figure 1.1. Usually, the starting point for building a product tree is the production of the end product and the use phase. Further diversification of the boxes in Figure 1.1 into singular processes, the so-called unit processes, as well as the inclusion of transports, diverse energy supply, co-products, and so on, turn this simplistic scheme, even with simple products, into very complex ‘product trees’ (diverse raw materials and energy supply, intermediate products, co-products, ancillary material, waste management including diverse disposal types and recycling).

Figure 1.1 Simplified life cycle of a tangible product.

Interconnected unit processes (life cycle or product tree) form a product system. The centre is a product, a process, a service or, in the widest sense, a human activity.⁹ In an LCA, systems that serve a specific function and therefore have a specified performance are analysed.

Therefore, the quantified performance (avail) of a product system is the intrinsic standard of comparison (reference unit). It is the sole correct basis for the definition of a ‘functional unit’.¹⁰

1.1.3 Functional Unit

Besides the cradle-to-grave analysis (thinking in terms of systems, life cycles or production trees), the functional unit is the second basic term in an LCA and is therefore to be explained here.

The function of a beverage packaging, for example, is – besides shielding of the liquid – above all, transportability and storability. The functional unit is most frequently defined as the provision of 1000 l liquid in a way to fulfil the technical aspects of the performance. This function can, for instance, be mapped with different packaging specifications (the following examples are arbitrarily chosen):

• 5000 0.2 l¹¹ pouches
• 2000 0.5 l reusable bottles of glass
• 1000 1 l single-use beverage carton
• 500 2 l PET (polyethylene terephthalate) single-use bottles.

Thus, for a comparison of packaging systems, the life cycle of 5000 pouches, 2000 reusable glass bottles, 1000 cardboards and 500 2 l PET bottles, which are four product systems that roughly fulfil the same function, needs to be analysed and compared.

Slight variations in performance (convenience, e.g. weight, user friendliness, aesthetics, customer behaviour, suitability as advertising medium or other side effects of packaging systems) are not important in this simplistic example. It is, however, important to note that sys...