Life cycle assessment inventory phase

Life cycle assessment is defined by ISO 14040 as compilation and evalu ation of inputs, outputs and the potential environmental impacts of a product system throughout its life cycle. The ISO standards regulate the procedural aspects of LCA. They do not, however, provide all the information required for carrying out an LCA study. The main phases of LCA are goal and scope definition, inventory, impact assessment, and interpretation. The various applications of LCA are not regulated by the standard (Fig. 15.1). 

Life-Cycle Interpretation is the phase of life-cycle assessment in which the findings of either the inventory analysis or the impact assessment, or both, are combined in consistence with the defined goal and scope in order to reach conclusions and recommendations. 

The inventory results should be presented in clear form, how much and what substances from the environment enter the system and how much get out. These results serve for subsequent life cycle impact assessment [48], The aim of the life cycle impact assessment is to measurably compare the environmental impacts of product systems and to compare their severity with new quantifiable variables identified as impact category. The impact categories are areas of specific environmental problems such as global warming, climate changes, acidification, eutrophication, ecotoxicity and others. Already in the phase of definition of the LCA study scope, it is necessary to describe what impact category will be applied and which of their environmental mechanisms will serve as a basis for impact assessment [46],... 

Life-cycle analysis A technique for assessing the environmental aspects and potential impacts associated with a product, by (1) compiling an inventory of relevant inputs and outputs of a process, from the extraction of raw resources to the final disposal of the product when it is no longer usable (so called from cradle to grave analysis) (2) evalnating the potential environmental impacts associated with those inputs and outputs and (3) interpreting the results of the inventory and impact phases in relation to the objectives of the study. 

Qatargas verified emissions inventory provides data which help in understanding key emission sources and areas of concern and providing a platform to progress Phase 3 of the strategy which covers technology assessment and life cycle analysis. This paper covers the technology assessment part only which is addressed in the sections below. 

In the third phase of an LCA, the life cycle impact assessment (LCIA), the inventory data are allocated to possible environmental impacts. Thereby, different... 

The International Standard Organization (ISO 14040) [26] breaks the LCA framework into four main stages (1) Goal and scope definition of the study. This stage clarifies the purposes of carrying the study while the assumptions and system boundaries are described clearly. (2) Life Cycle Inventory (LCI) analysis. LCI involves data collection and calculation procedures to quantify relevant inputs and outputs of the entire system defined within the system boundaries. (3) Life cycle impact assessment involves qualifying the potential environmental impacts of the inventory analysis results. (4) The interpretation of the results from the previous phases of the study in relation to the objective of the study. This interpretation can be in form of conclusions and recommendations to decision-makers for process changes to deliver improvement in the environmentel performance. 

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