Energy demand scenario

Most studies of the time evolution of the fuel cycle and the evolving mix of reactor types during future decades have been based on global (or national) nuclear energy demand scenario analyses which, up to now, have assumed the use of traditional reactor types, such as LWRs, pressurized heavy water reactors (PHWRs), and fast breeder reactors (FBRs). Possible implications of small reactors without on-site refuelling on the transition timing and strategy have not yet been assessed extensively. 

The results within the impact category GWP illustrate the great influence of both, the supply of chemicals (33% batch and 37% Conti wc, resp.) and the energy demand during synthesis (42% batch and 28% Conti wc, resp.) along the whole process chain. The disposal of the chemical refuse as well has a significant impact (23% both, batch and Conti wc). In the case of the worst-case scenario, the influence of the supply of the reaction device amoimts to 10% (assumed hfe time of the micro-structured devices 1 week) decreasing to 3% in Conti Scl (assumed life time of the micro-structured devices 3 month). 

Fig. 15.1 The world energy supply in the two Shell long-term energy scenarios Dynamics as Usual and Spirit of the Coming Age. The stacking order is such that carbon-neutral electricity-delivering sources (hydro, nuclear and renewables excluding biofuels) are at the bottom. When overlaid with the energy demand of the electricity sector (lower hashed area) one observes that carbon-free electricity supply falls far short of electricity...

The examples described in Sects. 2-4 all use carbon dioxide as the phase to dissolve the substrates and/or products. Under continuous operation, the CO2 phase thus serves as the mobile phase. However, one may also envisage a so-called inverted scenario, where SCCO2 becomes the stationary catalyst phase and a second liquid phase contains substrates and products. This allows the processing of components that are not or only very poorly soluble in SCCO2. Furthermore, as it uses a liquid as continuous phase, energy-demanding compression cycles of the CO2 phase are avoided. A necessary prerequisite is the use of a sufficiently C02-philic catalyst as outlined below. 

Capello et al.16 also assessed the environmental impacts of the life cycles of four solvent mixtures (methanol-water, ethanol-water, methanol-ethanol, and -propyl alcohol-water of different compositions w/w) that can be used for the solvolysis of p-methoxybenzoyl chloride. Different waste treatment scenarios for these binary mixtures (incineration and distillation) were analyzed. It appears that a solvent mixture with a high water content has a low environmental impact because the cumulative energy demand (CED) for the production of water is about three orders of magnitude lower than that for organic solvents.37... 

The transition to a new energy carrier requires a series of investments and enhancements not only in energy supply and distribution, but also in vehicles and other end-use technologies. This chapter addresses the demand side in three major categories, namely, transportation, stationary power, and industrial uses. Transportation demand scenarios are postulated for the present (i.e., 2002), the near term (2020), and the long term (2050). 

Several scenarios for global energy demand and supply by the year 2050 are discussed below. For ease of comparison, they are based on the same assumptions regarding energy demand concern for human welfare and environmental sustainability are assumed to lead to highly efficient energy consumption patterns based on increased concern for materials conservation and emphasis on non-material ("information society") types of activity. 

With respect to economic activity and energy demand, the scenario expects the development imtil the mid-21st century to be dominated on one... 

In normative models aimed at environmental sustainability, the natural approach to energy demand is to translate needs and goal satisfaction to energy requirements consistent already at demand level with environmental sustainability. For market-driven scenarios, basic needs and human goals play an equally important role, but secondary goals are more likely to be influenced by commercial interest rather than by personal motives. It is interesting that the basic needs approach is always taken in discussions of the development of societies with low economic activity, but rarely in discussions of highly industrialised cormtries. 

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