Ala Modarresi

Exergy analysis of biological hydrogen production

Abstract Exergy is defined as the maximum work obtainable while the system contacts with environment reversibly. Exergy analysis is a powerful approach for analysing both the quantity and the quality of energy. This concept identifies the system components with the highest thermodynamic inefficiency and the processes that cause them. Exergy analysis was applied to a novel process for biological production of hydrogen from biomass in a combined bioprocess employing thermophilic and phototrophic bacteria. The exergy content of the process streams is calculated using MS-Excel program. Calculation of exergy incorporates chemical exergy, physical exergy and exergy of mixing. Special attention is given to the calculation of chemical exergy of biomass- and sugar components involved in the process.