Calculation of chemical exergy values of some fuels

SUMMARY Calculation of Chemical Exergy Values of Some Fuels In this study, chemical exerji values of some solid and liguid fuels used in our country were calculated and the fuels are compared with each other depend on obtained exerji values. The first law analysis of thermodynamics which explains energy conservation principle, although necessary, does not give a complete picture ( or evaluating ) of the limitations and potantialities of the various components of an energy system. This way result in the installation of equipment that is not properly designed and matched with one another. But, the second law of thermodynamics, or exergy analysis gives better result for performans analysis and design of the energy systems. Exergy or availability energy is the maximum theoretical useful work obtainable as the system interact to equilibrium with the environment only. Alternatively, exergy is the minimum theoretical useful work required to form a quantity of matter from substances present in the environment and to bring the matter to a spesified state. Therfore, the use of exergy analysis ( or second law of thermodynamics ) in thermal system design and performance calculations is using more and more gradually. In the present study, the chemical exergy values of some hard coal, lignite, wood and biomass and other fuel-oil fuels used in our country were calculated by using exergy analysis method given in the literatüre and calculated results are given in tables and figures. According to the obtained chemical exergy calculations, the best fuels are Çatalağza ( hard coal ), Sorgun ( lignite ), Hybride Poplar ( wood, biomass ) and No.2 fuel-oil. Key Words: Energy, Exergy, Higher Heating Value, Coal, Wood, Biomass, Fuel-Oil. VI