Life cycle analysis methods

6 Life Cycle Energy and GHG Emissions Analyses 6.1 Life Cycle Analysis Methods 

This Section investigates life cycle energy and GHG emissions of a PV electrolytic H2 system. The boundaries of the life cycle energy and GHG emissions analyses are cradle to grave. Five life cycle stages are evaluated  

Stage 1 materials production, which includes ore extraction, milling, part casting and machining, and transportation  

Construction, office facility utilization and employee travel to and from work are included. All components are scaled to a thirty year operating life. 

I hr data source for levelized costs for combined-cycle electricity generating plants is EIA, Annual Energy Outlook 2005, Market Trends - Electricity Demand and Supply, Fig. 71 - Data Table. 

A generalized analysis such as this produces only approximate life cycle energy and GHG emissions estimates because of cross-sectional variation in product and material production processes and local energy sources. Sensitivity analysis is an analytical tool to evaluate the effect of variances in life cycle estimation parameters on results. The sensitivity analysis performed in this study applies a 25% variance to each of the life cycle estimation parameters. 

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Capital investment decisions are best made within the context of a life-cycle cost analysis. Life-cycle cost analysis focuses on the costs incurred over the life of the investment, assuming only candidate investments are considered that meet minimally acceptable performance standards in terms of the non-inonetary impacts of the investment. Using life-cycle analysis, the capital investment decision takes into account not just the initial acquisition or purchase cost, but maintenance, energy use, the expected life of the investment, and the opportunity cost of capital. When revenue considerations are prominent, an alternative method of analysis such as net benefit or net present value may be preferred. 

Capital investments can also be selected on the basis of other measures of performance such as return on investment, internal rate of return, and benefit-cost ratio (or savings-to-investment ratio). Flowever, care must be taken in the application of these methods, as an incremental analysis is required to ensure consistent comparison of mutually exclusive alternatives. Also, rather than requiring a separate value to be calculated for each alternative, as in the case of the life-cycle cost method, these other methods incorporate the difference between two mutually exclusive alternatives within a single measure. For example, the net benefits measure directly pressures the degree to which one alternative is more economically desirable than another. 

Methodically devised and established methods (and criteria) of substance and process assessment and evaluation like risk analysis, toxicological and ecotoxi-cological analyses, life-cycle-analysis and cost-benefit analysis . But also much simpler approaches, which in practice play an important role for assessing formulations and snbstance properties (e.g. the nse of negative and/or positive lists). 

Handbook of Green Chemistry and Technology, J. H. Clark and D. J. Macquarrie, Eds., Blackwell Publishing 2002, 540 pp., ISBN 0-632-05715-7. This collection of 22 review essays covers all the important areas of green chemistry, including environmental impact and life-cycle analysis, waste minimization, catalysts and their industrial applications, new synthesis methods, dean energy, and novel solvent systems. The chapters are well referenced and contain pertinent examples and case studies. 

The short summary of the life-cycle method preceding the actual analyses is necessary, because life-cycle analysis is not a standard calculation. In the literature, one finds various definitions ranging from restricted net energy analyses over environmental impact studies to the full consideration of both environmental and social impacts. It is the latter methodology, more fully described in Sorensen (2004a), which will be employed here. 

Vinyl chloride monomer (VCM) manufacture Maximization of VCM production and minimization of environmental burden, environmental impact and operating cost simultaneously. e-constraint method A design methodology consisting of 4 steps was proposed and applied to VCM plant The steps are (1) life cycle analysis of the process, (2) formulation of the design problem, (3) MOO, and (4) multi-criteria decision-making to find best compromise solutions. Khan et al. (2001)... 

Industrial ecology life-cycle analysis detection, monitoring, measurement science (4) development of noninvasive spectroscopic technology synchrotron-based methods, availability and development application of GC-MS computation and modeling (4) satellite technology (profiles, surface temperature, etc.)... 

The fact that menthol is produced from both renewable and fossil feedstocks allows for an interesting study in sustainability. In order to produce the same crop year after year, it is necessary to use fertilisers to replenish the nitrogen and minerals which the plant takes from the soil. Secondary metabolites such as menthol and essential oils occur at a level of, at most, only a few per cent of the dry weight of the herb. Therefore, in order to produce an economic return, it is necessary to use efficient, mechanical methods of cultivation and harvesting. A full life cycle analysis of menthol production reveals that production from cultivation of mint plants consumes more fossil fuel, produces more carbon dioxide effluent and has more environmental impact than either of the leading synthetic routes. 

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