Energy conversion exergy

Chapters 9 through 12 demonstrate thermodynamic, or exergy analysis of industrial processes. First, Chapter 9 deals with the most common energy conversion processes. Then, Chapter 10 presents this analysis for an important industrial separation process, that of propane and propylene. Finally, Chapter 11 analyzes two industrial chemical processes the production of polyethylene. Chapter 12 is included to discuss life cycle analysis in particular its extension into exergetic life cycle analysis, which includes the "fate" or history of the quality of energy. 

In this chapter, we explore how the exergy concept can be used in the analysis of energy conversion processes. We provide a brief overview of commonly used technologies and analyze the thermodynamic efficiency of (1) coal and gas combustion, (2) a simple steam power plant, (3) gas turbine, and (4) combined cycle and cogeneration. At the end of this chapter, we summarize our findings with some concluding remarks. 

In the previous chapters, thermodynamic analysis is used to improve processes. However, as pointed out in Chapter 9 (Energy Conversion), the exergy analysis did not make any distinction between the combustion of coal and natural gas and, as a result, could not make any statements regarding toxicity or environmental impact of exploration, production and use of the two fuels. A technique that can do this is LCA. What exactly is life cycle analysis In ISO 14040 [1], life cycle analysis (or life cycle assessment) is defined as "the compilation and evaluation of the inputs, outputs and potential environmental impacts of a product throughout its life cycle."... 

Design Optimization. The goal in design optimization of energy conversion systems is to select the equipment which strikes the best balance between overall capital (and other) costs and the cost of the exergy input—for the particular type of system opera-... 

Figure 3. Exergy ratios of energy conversion steps.

Johnson, D. H., "Exergy of the Ocean Thermal Resource and the Second-Law Efficiency of Idealized Ocean Thermal Energy Conversion Power Cycles," Solar Energy Research Institute, Golden, CO, Report No. SERI/TR-252-1420R, Available as NTIS PCA03/MF 01, National Technical Information Service (1982). 

Khalifa, H. E., "Economic Implications of the Exergy and Thermal Efficiencies of Energy Conversion Systems,"... 

Ishida, M. and Nishida, N., "Evaluation of Coal Conversion Processes from an Energy Efficient Use Viewpoint (III) Energy and Exergy Analysis of a Gasification Process,"... 

Steam-reforming shows quite good energy and exergy conversion efficiencies, 46 and 42%, and a solar transformity of the expected order of magnitude (1.15 x 10 seJ/J of hydrogen, labor and services included). Steam-... 

THERMOECONOMICS is the branch of thermal sciences that combines a thermodynamic (exergy) analysis with economic principles to provide the designer or operator of an energy-conversion system with information which is not available through conventional thermodynamic analysis and economic evaluation but is cmcial to the design and operation of a cost-effective system. Thermoeconomics rests on the notion that exergy (available... 

The standard chemical exergy of a substance not present in the environment can be calculated by considering a reversible reaction of the substance with other substances for which the standard chemical exergies are known. For energy-conversion processes, calculation of the exergy of fossil fuels is particularly important. 

Atsonios K, Panopoulos KD, Doukelis A, Koumanakos A, Kakaras Em, 2012. Exergy analysis of a hydrogen fired combined cycle with natural gas reformin-gand membrane assisted shift reactors for COj capture. Energy Conversion and Management 60196-203... 

Figure 1.1. Exergy efficiencies of the principal types of energy conversion systems [2].

Chao, Z., Yan, W., 2006, Exergy cost analysis of a coal fired power plant based on structural theory of thermoeconomics. Energy Conversion and Management, 47 817-843. 

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