Exergetic and economic analysis of a cheese whey wastewater anaerobic treatment plant with a cogeneration system

Abstract

This paper investigates the extension of an existing steam production plant in order to cover both thermal and electrical needs of a factory. The plant uses biogas produced from cheese whey (CW) wastewater anaerobic digestion treatment. For this purpose a microturbine is chosen among the commercially available microturbines. The selection of the suitable microturbine for matching with the existing system is not a trivial task: the limitations (the amount of the biogas produced), the requirements (the amount of the steam produced) of the existing system, and the specifications of the microturbine by the manufacturer must be satisfied. The system considered was studied through the development of an appropriate simulation model validated with available data. Then an exergetic and economic analysis for the extended system was carried out. The results showed that the matching performance of the microturbine with the existing system has positive effects on the exergy efficiency of the plant as well as to the incomes and savings for the factory which are significantly increased compared to the existing ones. Thus, this study proves that the anaerobic treatment of CW is a sustainable way for the factory to treat the whey it produces. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.