Life Cycle Impact Assessment

Abstract

This chapter is dedicated to the third phase of an LCA study, the Life 6 Cycle Impact Assessment (LCIA) where the life cycle inventory's information on 7 elementary flows is translated into environmental impact scores. In contrast to the 8 three other LCA phases, LCIA is in practice largely automated by LCA software, 9 but the underlying principles, models and factors should still be well understood by 10 practitioners to ensure the insight that is needed for a qualified interpretation of the 11 results. This chapter teaches the fundamentals of LCIA and opens the black box of 12 LCIA with its characterisation models and factors to inform the reader about: (1) the 13 main purpose and characteristics of LCIA, (2) the mandatory and optional steps of 14 LCIA according to the ISO standard, and (3) the science and methods underlying 15 the assessment for each environmental impact category. For each impact category, 16 the reader is taken through (a) the underlying environmental problem, (b) the 17 underlying environmental mechanism and its fundamental modelling principles, 18 (c) the main anthropogenic sources causing the problem and (d) the main methods 19 available in LCIA. An annex to this book offers a comprehensive qualitative 20 comparison of the main elements and properties of the most widely used and also 21 the latest LCIA methods for each impact category, to further assist the advanced 22practitioner to make an informed choice between LCIA methods. 25After studying this chapter, the reader should be able to: 26• Explain and discuss the process and main purposes of the LCIA phase of an 27 LCA study. 28• Distinguish and explain the mandatory and optional steps according to inter-29 national standards for LCA. 30• Differentiate and describe each of the impact categories applied in LCIA 31 regarding: 32the underlying environmental problem. 33the environmental mechanism and its fundamental modelling principles. 34the main anthropogenic sources causing the problem. 35the main methods used in LCIA. 36 37 38 39 10.1 Introduction 40 In practice, the LCIA phase is largely automated and essentially requires the 41 practitioner to choose an LCIA method and a few other settings for it via menus and 42 buttons in LCA software. However, as straightforward as that may seem, without 43 understanding a few basic, underlying principles and the meaning of the indicators, 44 neither an informed choice of LCIA method nor a meaningful and robust inter-45 pretation of LCA results is possible. However, the important extent of science and 46 its inherent multidisciplinarity frequently result in a perceived opacity of this phase. 47 This chapter intends to open the black box of LCIA with its characterisation models 48 and factors, and to accessibly explain (1) its main purpose and characteristics, 49(2) the mandatory and optional steps according to ISO and (3) the meaning and 50 handling of each impact category. While this chapter is a pedagogical and focused 51 introduction into the complex and broad aspects of LCIA, a more profound a...

GHG Emissions by (Petro)Chemical Processes and Decarbonization Priorities—A Review

“…The second fundamental indicator to be evaluated is the gate-to-gate GHG emission factor. This parameter (borrowed from the Life Cycle Assessment (LCA) jargon [46,47] and typically expressed in mass of carbon dioxide equivalent per a specific "functional unit") quantifies the carbon footprint associated with a production plant (from the entrance "gate" to the exit "gate"). Similar indicators are the cradle-to-gate and cradle-to-grave GHG emission factors, wherein "cradle" accounts for the extraction of raw materials.…”