Life-cycle inventory analysis

A life cycle assessment (LCA), also known as life cycle analysis, of a product or process begins with an inventory of the energy and environmental flows associated with a product from "cradle to grave" and provides information on the raw materials used from the environment, energy resources consumed, and air, water, and solid waste emissions generated. GHGs and other wastes, sinks, and emissions may then be assessed (Sheehan et ah, 1998). The net GHG emissions calculated from an LCA are usually reported per imit of product or as the carbon footprint. 

The inventory stage involves the collection of all the data that will be used in the life-cycle analysis. The quality of the data is an important part of the life-cycle inventory (LCI) process, and, as with any model, the results of an LCA are only as good as the data inputs. There are two basic sources of data for an LCA, primary and secondary in nature. Primary data are derived directly from the... 

Figure 12 shows the basic framework for compiling an inventory of wastes, emissions, and energy use associated with the manufacture, use, and disposal of a product (SETAC, 1991). Compiling an inventory is just the first step in a life cycle analysis, however. After the inventory is compiled, the impacts of raw material use, waste generation, and emission generation must be assessed. Finally, after the life cycle impacts are assessed, mechanisms for reducing adverse environmental impacts can be... 

Obviously, the first and most important factor in the inventory analysis stage is the overall composition of the battery system. Technically, a life cycle analysis can only be specifically performed on a specific battery composition, and there is often great variety in the compositions for batteries that nominally all belong to the same family. In addition, a rigorous life cycle analysis should consider every material in the battery, no matter how minute the environmental impacts may appear to be. The tendency in most life cycle analyses on battery systems to date has been to concentrate on the hazardous materials or heavy metals contained in those batteries while ignoring contributions which may arise from greater amounts of less high-profile substances. For example, life... 

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. 

It is environmentally important to perform a life cycle assessment analysis, not only for non-biodegradable polymers but also for partially biodegradable or even completely biodegradable polymers. Life cycle analysis (LCA) is a tool which helps in understanding the environmental impact associated with the products, processes and activities throughout the life of a polymer. The life cycle of vegetable oil-based polymers is shown in Rg. 2.6. Thus a complete LCA would include three separate but interrelated components, an inventory analysis, an impact analysis and an improvement analysis. 

The components of a life cycle analysis include the life cycle inventory. These involve a complete resource requirement to be identified in terms of materials and eneigy. The life cycle impact assessment characterizes and assesses the effects of the environmental emissions. The life cycle Improvement analysis is used to quantify the life cycle inventory and import, and is used to assess possible environmental improvements that can be made. 

Once the life-cycle inventory has been quantified, we can attempt to characterize and assess the eflfects of the environmental emissions in a life-cycle impact analysis. While the life-cycle inventory can, in principle at least, be readily assessed, the resulting impact is far from straightforward to assess. Environmental impacts are usually not directly comparable. For example, how do we compare the production of a kilogram of heavy metal sludge waste with the production of a ton of contaminated aqueous waste A comparision of two life cycles is required to pick the preferred life cycle. 

Having attempted to quantify the life-cycle inventory and impact, a life-cycle improvement analysis suggests environmental improvements. 

ISO, F.nvironmental Management—Life Cycle Assessment—Goal and Scope Definition and Inventory Analysis (ISO 14041). 

Jensen WB (1997) A note on the term Chalcogen . J Chem Educ 74 1063-1064 Fischer W (2001) A second note on the term Chalcogen . J Chem Educ 78 1333 Fthenakis V, Wang W, Kim HC (2009) Life cycle inventory analysis of the production of metals used in photovoltaics. Renewable Sustainable Energy Rev 13 493-517 Waitkins GR, Bearse AE, Shutt R (1942) Industrial utilization of selenium and tellurium. Ind Eng Chem 34 899-910... 

Capello, C., Hellweg, S., Badertscher, B., Hungerbuhler, K. (2005) Life-Cycle Inventory of Waste Solvent Distillation Statistical Analysis of Empirical Data. Environmental Science and Technology, 39, 5885-5892. 

ISO 14041 1998 (1998) Environmental Management - Life Cycle Assessment - Goal and Scope Definition and Life Cycle Inventory Analysis. European Commitee for Standardisation, Brussels, Belgium. 

Similarly, Overcash et al. [32] produced an engineering rule-of-practice-based analysis of separate unit processes used in manufacturing. The information is collated in the form of a unit process life cycle inventory, which then helps to evaluate the manufactured products through the quantification of various parameters, including input materials, energy requirements, material losses and machine variables. 

Rebitzer G, Ekvall T, Frischknecht R, Hunkeler D, Norris G, Rydberg T, Schmidt WP, Suh S, Weidema BP, Pennington DW. Life Cycle Assessment Part 1 Framework, Goal and Scope Definition, Inventory Analysis, and Applications. Environment International. 2004 30(5) 701-720. DOI 10.1016/j.envint.2003.11.005... 

ISO (1998) ISO 14041 Environmental management - Life cycle assessment - Goal and scope definition and inventory analysis. International Organisation for Standardisation, Geneva... 

The aim of the Life Cycle Impact Assessment (LCIA) is to facilitate the interpretation of the results of the inventory analysis. The result of the inventory analysis is an emission profile for each alternative system. In this study the emission profile is the total of all emissions to air, water and soil from the grave-to-cradle chain for the use of cushion vinyl floor covering, including the up chain processes, like electricity production and the down chain processes, like the incineration and landfill of the waste. Such an emission profile may consist of hundreds of emissions and extractions. In LCA impact assessment the total of interventions (emissions, extractions) of a process chain is evaluated in terms of environmental problems (impact categories). 

Authors have stressed the importance of LCAs for comparing environmental and energy impacts, outlined the difficulties encountered in conducting such assessments, and provided examples of past LCAs. They addressed additional issues and also examined the usefulness of LCAs in formulating public policy. When a given pollutant arises at multiple sites, life-cycle impact analysis is often replaced by life-cycle inventory analysis (Graedel et al., 1995). 

The core of LCA is a cradle-to-grave life-cycle inventory analysis that is fundamentally an engineering exercise describing a chemical, material, and energy accounting balance for the entire product system. The various inputs and outputs are collected or inventoried for each unit operation in the defined system (see fig. 4.4). A key qualifier in the figure is the definition of the system boundary, as it will directly affect the quality of the final results and conclusions. The inventory practice and methods are relatively well defined. 

Figure 4.4 Elements of a life cycle inventory analysis.

Recently, terms such as life cycle inventory (LCI), cradle-to-grave-analysis, eco-balancing, and material flow analysis have come into use. 

Inventory analysis involves data collection and calculation procedures to quantify relevant inputs and outputs of a product system. These inputs and outputs may include the use of resources and releases to air, water, and land associated with the system. These data also constitute the input to the life-cycle impact assessment. 

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