Energetic aspects

Thermodynamic calculations [3] show that, for an electrolysis cell involving carbon anodes, the theoretical electrical energy consumption is 6.34 kWh/kg A1 while, for inert anodes, the theoretical consumption is 9.26 kWh/kg A1 at a temperature of 960 °C. The energy consumption for producing prebaked carbon anodes is about 17% of the energy required for electrolysis [3,4, 6]. 

On the other hand, the anode reaction on carbon is associated with considerable overvoltage of 0.6-0.8 V [3,4]. The anodic overvoltage on inert anodes is much lower, that is 0.15 V [25-27]. Even so, the polarisation potential of an inert anode is higher than that of a carbon anode. 

If inert anodes are used instead of carbon anodes, an advantage of 17% of the actual consumption of electrical energy (17% of 14 kWh/kg A1 = 2.4 kWh/kg Al) can be gained, but this energy is not saved during 

the total consumption of energy for aluminium production is about 14.0kWh/kg Al (for electrolysis) and the energy consumption for producing prebaked carbon anodes is 2.5kWh/kg Al, therefore totally 16.5-17.0 kWh/kg Al. Likewise, one should take into account the energy content in 500kg carbon anodes/t Al. 

The data in Table 1.4.1 are calculated for an electrolysis temperature of 960 °C. In the case of using a K3AlFg-based electrolyte, the electrolysis can take place at temperatures of 700-750 °C, and so a further saving of electrical energy will result. 

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Woledge, R. C. Curtin, N. A. and Ilomsher, E. (1985). Energetic Aspects of Muscle Contractiom Monographs of the Physiology Society, No. 41. Boston, MA Academic Press. 

Miller, I. R. Structural and energetic aspects of charge transport in lipid layers and in biological membranes, in Topics in Bioelectrochemistry and Bioenergetics, Vol. 4 (ed.) Milazzo, G., New York, Wiley 1981... 

The energetic aspects of underpotential deposition can be investigated by a slow (i.e., a few millivolts per second) potential scan starting at a potential so high that no adsorption takes place. As the potential is lowered, one or more current peaks axe observed, which are caused by the adsorption of the metal ions (see Fig. 4.9). According to the usual convention, the adsorption current is negative (i.e., cathodic). Different peaks may correspond to different adsorption sites, or to different structures of the adsorbate layer. If the potential is scanned further past the equilibrium potential bulk deposition is observed. 

The number of hydrogen bonds per molecule in liquid water depends on the balance between the favorable energetic aspect of optimal hydrogen bonding and the unfavorable entropy considerations resulting from restrictions in water molecule location (Wallqvist and Mountain, 1999). 

The energetic aspects of the peculiarity of isobutene, and of the individual steps in cationic polymerisations have been discussed in detail by Plesch [4a]. A discussion of the energetics of the closely related ionic isomerisation and cracking reactions has been given by Greensfelder [4b] see also Chapter 1. 

In the following sections we will focus on geometric and energetic aspects of the various species which compose the mechanism of Figure 3. We will start with the species prior olefin coordination (Section 3.1), we will... 

R. L. Schowen, Structural and Energetic Aspects of Proteolytic Catalysis by Enzymes Charge-Relay Catalysis in the Function of Serine Proteases , in Mechanistic Principles of Enzyme Activity , Eds. J. F. Liebman, A. Greenberg, VCH, New York, 1988, p. 119 — 165. 

Schowen, R.L. (1988). Structural and energetic aspects of protolytic catalysis by enzymes charge-relay catalysis in the function of serine proteases. In Mechanistic Principles of Enzyme Activity, Liebman, J.P. and Greenberg, A. (eds), pp. 119-168. VCH Publishers, New York... 

Solvation is a process in which solute particles (molecules or ions) in a solution interact with the solvent molecules surrounding them. Solvation in an aqueous solution is called hydration. The solvation energy is defined as the standard chemical potential of a solute in the solution referred to that in the gaseous state.11 The solvation of a solute has a significant influence on its dissolution and on the chemical reactions in which it participates. Conversely, the solvent effect on dissolution or on a chemical reaction can be predicted quantitatively from knowledge of the solvation energies of the relevant solutes. In this chapter, we mainly deal with the energetic aspects of ion solvation and its effects on the behavior of ions and electrolytes in solutions. 

Now let us study the energetic aspect in more detail. For the monomolec-ular steps we obtain... 

Esener, A. A., Roels, J. A. and Kossen, N. W. F. Biotechnoi. Bioeng. 25 (1983) 2803. Theory and applications of unstructured growth models Kinetic and energetic aspects. 

Structural and energetic aspects of the ene reaction have been investigated320 using a variety of computational methods incorporating different ways of accounting for electron configuration, and the mechanistic course of Lewis acid-catalysed cycloaddi-... 

Membrane unit operations are today largely used in many different applications for their higher efficiency in comparison with traditional separation systems. Moreover the integration of different membrane operations in the same unit, or in combination with conventional ones, offers important benefits in terms of product quality, plant compactness, environmental impact, and energetic aspects. 

In 1993, L.T. Zhuravlev35 published a review article of work performed in the former USSR on the surface characterization of amorphous silica. This review article is a very important document in the study of the silanol distribution. Also, the energetical aspects of the dehydration and dehydroxylation processes are discussed in detail. The determination of the silanol number as a function of treatment temperature has already been discussed in chapter 4. 

Ritchie, J.M. (1973). Energetic aspects of nerve conduction. Prog. Biophys. Mol. Biol. 26, 147-187. 

Maurer, M. Schwegler, P. and T.A. Larsen (2003) Nutrients in urine energetic aspects of removal and recovery.- Water Science and Technology 48, 37-46. 

Acetylenic ethers follow the same pathway, but the less favorable energetical aspects dictate the use of harsher reaction conditions. 

The proton transfer in ionized phenol-water clusters is strongly dependent on the number of water molecules and their specific organization, i.e., the PT is a process assisted by the solvent [72], Most of the theoretical studies of PT in [C6H50H-(H20) ],+ clusters were focused on the structure, vibrational, [79,80,81] and energetic aspects [77,78]. However, much less is known on the dynamics of PT. 

A negative or zero interfacial tension is a necessary condition for the emulsification which leads to the phase inversion reported by Bender (5). This is one of the most important criteria for the particle formation mechanism. Unfortunately this surface energetics aspect has not been discussed by previous workers. 

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