Thermodynamic energy conversion

Landsberg P. T and Tonge G. (1980), Thermodynamic energy conversion efficiencies , J. Appl. Phys. 51, R1-R20. 

Table 4.1 The transferred electrons (Ne), electromotive force ( °), volume energy density (IVe), and thermodynamic energy conversion efficiency (erev) of electrooxidation of selected alcohols at standard conditions.

The subject of thermodynamics embodies the principles of energy conversion in macroscopic systems. The general restrictions which experience has shown to apply to all such conversions are known as the laws of thermodynamics. These laws are fundamental in the sense that they cannot be derived from anything more basic. They do not require to be proven, but their acceptance is based on the fact that the conclusions derived from them are consistent with the results of all known experiments. 

De Vos, A. Endoreversible Thermodynamics of Solar Energy Conversion, Chapter 6, Oxford Science Publishers, Oxford, 1992. 

Eq. 2 is notable in the context of the energy conversion scheme proposed above because the separated redox products, quite remarkably, have the thermodynamic ability over a broad pH range to either oxidize water (using Ru(bpy)o +) or to reduce water (using PQ+). ... 

From a consideration of thermodynamics, solar energy conversion by means of photoinduced charge separation followed by water splitting is a feasible process. 

A. De Vos, Endoreversible Thermodynamics of Solar Energy Conversion, Oxford University Press, Oxford, 1992 R. S. Berry, V. A. Kazakov, S. Sieniutycz, Z. Szwast, and A. M. Tsvihn, Thermodynamic Optimization of Finite-Time Processes, John Wiley Sons, Chichester, 2000) P. Salamon, J. D. Nulton, G. Siragusa, T. R. Andersen, and A. Limon, Energy 26, 307 (2001). 

The energy storage and power characteristics of electrochemical energy conversion systems follow directly from the thermodynamic and kinetic formulations for chemical reactions as adapted to electrochemical reactions. First, the basic thermodynamic considerations are treated. The basic thermodynamic equations for a reversible electrochemical transformation are given as... 

Electrochemical energy conversion devices are pervasive in our daily lives. Batteries, fuel cells and supercapacitors belong to the same family of energy conversion devices. They are all based on the fundamentals of electrochemical thermodynamics and kinetics. All three are needed to service the wide energy requirements of various devices and systems. Neither... 

An energy conversion cyclic system that converts heat to work, and sometimes work to heat, is the foremost objective of thermodynamics. 

Incident solar energy is absorbed by the surface water of the oceans. Ocean surface temperatures in excess of 26°C occur near the equator. Pure water has a maximum density at a temperature of 4°C. The chilled water tends to settle to the depths of the ocean. The combination of the warmed ocean surface water and cold deep ocean water provides the thermodynamic condition needed to operate a heat engine called ocean thermal energy conversion (OTEC). A typical closed-cycle OTEC Rankine cycle using a working fluid such as ammonia or a freon is suggested. 

A numerical example of the carbon dioxide supercritical cycle has been made by Feher (Feher, E.G., The super-critical thermodynamic power cycle. Energy Conversion, vol. 8, pp. 85-90, 1968). The reasons for the neglect of the supercritical cycle until now are not known. 

Otherwise, the mixture is called a nonazeotrope. A nonazeotropic mixture has a temperature distribution parallel to that of the thermal reservoir. Note that one of the requirements for the nonazeotropic mixture energy conversion improvement is to have a nonconstant temperature heat source and heat sink. The proper choice of best combination of the nonazeotropic mixture is still not entirely understood. Uncertainties in modeling the thermodynamic and heat-transfer aspects of the nonazeotropic mixture refrigeration cycle are such that the probability of realizing significant net benefits in actual application is also not fully known. 

The first law of thermodynamics relates the energy conversion produced by chemical reaction of an energetic material to the work acting on a propulsive or explosive system. The heat produced by chemical reaction q) is converted into the internal energy of the reaction product (e) and the work done to the system [w] according to... 

It should be noted that r y is the maximum thermodynamic efficiency obtained under reversible conditions, i.e., such that the rate of any photochemical reaction from D is infinitesimally slow. Although riy has some theoretical interest, it has no practical interest since we are interested in maximizing the rate of a photochemical reaction from D which will lead to the production of useful work. The rate of energy conversion by such a process can be defined as... 

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