Embedded energy

GHG emissions associated with the raw material are determined from the energy used to manufacture the plastic materials and the fuel used to transport them to the plant. The transportation and manufacture of the secondary packaging used to transport the primary raw materials and finished materials may also be considered. The embedded energy of the materials, if made from petroleum products, is also accounted for when it is used as a raw material (Keoleian and Spitzley, 1999 Spitzley et al., 1997). End-of-life emissions may also be included in LCA of milk packaging and include fhe energy used fo recycle the package or emissions in the form of CH4 from a landfill. 

Fig. 5.16 The embedding energy F(p) for H and the rare gas atoms He and Ne in a free-electron gas of density p. (After Puska et a . (1981).)...

Note that we have imitated Johnson s notation in which the quantity / is a constant factor that appears in the determination of the density p, and the parameters ro, and o are other parameters that are determined through the fitting procedure. Once the density function and the pair potentiai have been specified, fhe determination of the embedding function is complete in principle. In this case, because of the choice of functions, the relevant equations can be solved analytically with the result that the embedding energy is given by... 

Fig. 4.9. Various representations of the embedding energy for Cu (adapted from Johnson (1988)). The solid curve is the embedding fnnction for Cu derived from UBER as described in text, the dashed curve is a fit for the embedding function and the dotted curve corresponds to an embedding function of the Finnis-Sinclair form in which F(p) a...

These are determined from the self-consistent-field local density (SCF-LD) functional calculations (Puska et al. 1981) on the embedding energy of an atom in jellium. The values as a function of jellium densities are represented by a Morse-like form. (It is not strictly a Morse potential since density is the variable instead of distance.) The variable, r depends upon the density of the solid at the position of A ... 

Figure 20. Embedding energy as a function of jellium density for two different atoms. The data are from Puska et al (1981).

This equation shows, that the single-reactant indices are the lst-order criteria. Indeed, for the fixed perturbations [Aa, Ax(ij)] and [Aa, Ax(r2)] due to the same agent attacking the two alternative locations rj and r2 in a molecule, the trends in A F xfri)] and Al/ija,x(r2) are reflected by those in /i Cr, ) and /iJt.(r2), so that the local potential constitute a valid single-reactant reactivity criterion. The embedding energy contributions are of the 2nd-order in such a perturbational approach. 

These normalized response quantities determine the corresponding embedding energy contributions, the quadratic functions of the reaction stimuli Aa and Ax(r). 

Such embedding energy contributions are included in all 2nd-order perturba-tional approaches to chemical reactivity [3-13,47,51,52,57,73,75,80,83,85-89]. 

Figure 2.80. Embedding energies of He, II, Li, B, N, C, O and Ne in a homogeneous electron gas (jellium) as a function of electron-gas densityt l...

Quaternary incinerating waste as a way of reclaiming the embedded energy. 

Tertiary recycling involves chemical breakdown of nylon or PET for repolymerisation. This requires either clean, sorted pre-consumer waste or post-consumer waste, sorted by fibre type, as a feedstock. In quaternary recycling, the embedded energy of textiles can be reclaimed through incineration (Wang, 2010). This final approach is not addressed in this chapter. 

Twelve parameters were required for every specific element in order to develop the function within the modified embedded-atom method [40]. The Usted values include the sublimation energy of elements, nearest-neighbor distance, embedding energy, factors for atomic densities, and so on. The modified embedded-atom method was successfiiUy applied to calculating various bonding characteristics. 

The plastic bottle in this comparison emerges as being comparable in embedded energy cost (within the error of at least 10%), but appears to be superior in terms of its carbon footprint, to aluminum cans. The outcome of the LCA exercise is sensitive... 

TABLE 5.4 Embedded Energy, Solid Waste Generated, and GWP Per 10,000 Units of 12 oz Packages Mannfactnred... 

AU plastic waste including htter is a material of value in terms of the embedded energy and the nonrenewable materials that comprise it. It is clearly a resource or a raw material that must ideally be recycled and its material and/or energy resources extracted for reuse. Degradability and compostability do not facilitate this key sustainability objective. 

TABLE 8.1 The Embedded Energy and GWP of Selected Packaged Food Items... 

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