Available energy applications

A number of methods have been described in earlier sections whereby the surface free energy or total energy could be estimated. Generally, it was necessary to assume that the surface area was known by some other means conversely, if some estimate of the specific thermodynamic quantity is available, the application may be reversed to give a surface area determination. This is true if the heat of solution of a powder (Section VII-5B), its heat of immersion (Section X-3A), or its solubility increase (Section X-2) are known. 

Fig. 11.15, the loss of capacity with cycle life is shown. The available energy capacity can be calculated as 35 kW h at the beginning of the battery s life and 21 kW h at the end. The energy density of 86 W h kg at the beginning is attractive compared with the conventional secondary batteries of 40 W h kg or less. The energy capability with cycling must be improved for practical applications. 

Distribution of Carbon. Estimation of the amount of biomass carbon on the earth s surface is a problem in global statistical analysis. Although reasonable projections have been made using the best available data, maps, surveys, and a host of assumptions, the validity of the results is impossible to support with hard data because of the nature of the problem. Nevertheless, such analyses must be performed to assess the feasibility of biomass energy systems and the gross types of biomass available for energy applications. 

Climate and Environmental Factors. The biomass species selected for energy applications and the climate must be compatible to facilitate operation of fuel farms. The three primary climatic parameters that have the most influence on the productivity of an indigenous or transplanted species are insolation, rainfall, and temperature. Natural fluctuations in these factors remove them from human control, but the information compiled over the years in meteorological records and from agricultural practice supplies a valuable data bank from which to develop biomass energy applications. Ambient carbon dioxide concentration and the availability of nutrients are also important factors in biomass production. 

Aluminum—air battery. A second potential application of this available energy is based on electrochemical oxidation of aluminum in air to produce electricity. In an aluminum—air battery, for example, thin coils of aluminum strip may be used as the fuel. No elech ic battery recharging would be required since the aluminum is consumed to generate the electricity directly. This fuel would not give off fumes or pollute and could be stored in solid form indefinitely. If this concept materializes into commercial viability, it will provide the energy needed for electric vehicles. 

Finally, the aura of mystery in nuclear energy applications should be dispelled. Just as a food processor need not know how to design and build a refrigerator or freezing unit, neither should he be expected to know how to design or build a radiation unit. In either case, companies and individuals are available to assume this burden for him. However, for a company to remain uninformed of the applications and advantages offered by radiation over conventional techniques will ensure conformity to the old adage, always a bridesmaid, but never a bride.,... 

Wepfer, W.J., "Applications of Available Energy Accounting," Thermodynamics Second Law Analysis, A.C.S. Symposium... 

A general thrust of the chapter will be SIMPLICITY. Differences in terminology have been eliminated wherever possible. In this analysis Availability, Available Energy, Exergy, and Work will be used as equivalent. This means that kinetic and potential energy effects and the potential work to be derived from the diffusion of chemical species into equilibrium with the environment have been ignored. This simplification may introduce significant inaccuracies in some studies, but is not important here. The intent is to demonstrate that simplified - perhaps even approximate - analysis can have valuable practical applications. 

In the application of this method to a Rankine cycle cogeneration system, generalized costing equations for the major components have been developed. Also, the utility of the method was extended by relaxing the rule that each state variable (and hence each Lagrange constraint) must correspond to an available-energy flow. The applicability was further extended by the introduction of numerical techniques necessary for the purpose of evaluating partial derivatives of steam table data. 

This paper provides a framework for the application of Second Law based design methodology to separation systems. A relationship is derived for the available-energy destruction in a binary separation column as a function of the reflux ratio and the feed and product mass fractions. This derivation is limited to separations in which the entropy production is predominately due to mass transfers. 

F. Basic principles and applications of thermoeconomics and available energy costing (105 to 115). 

Schiff, D., "Entropy (Available Energy) Analysis, Energy and Environmental Control Applications," Technical Report, Mitre Corporation, McLean, VA, NTIS PC A05/MF A01,... 

F. Basic Principles and Applications of Thermoeconomics and Available Energy Costing... 

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