Department of Mechanical Engineering,Sharif University of Technology
Abstract. By simultaneously applying pinch technology and the exergoeconomic method to a complex
process system, benecial and energy-ecient measures are identied. The three-link-model" exergoeconomic
methodology optimizes the design and operability of a system. In this work, contrary to traditional
exergoeconomic methods, a reversed method is used. The approach proposed for the optimization of
such a complex system is to iteratively optimize subsystems. Since the reversed exergoeconomic method
is used, assumptions considered by Tsatsaronis (based on four assumptions for calculating the costoptimal
exergetic eciency and relative cost dierence) are not applicable and new assumptions are to be
considered. Unlike traditional exergoeconomic methods, the product exergetic specic cost is considered to
be known and the objective will be to maximize the exergetic cost of the fuel. Heat
ows costs are calculated
with the assistance of a Pinch analysis. The strength of the combination of a Pinch analysis and the
exergoeconomic method is elucidated in a case study applied to the Mazandaran wood and paper industry.
Replacement of the pressure valve and Direct Cyclone Contact Evaporation (DCCE) is proposed, while by
selection of the optimum decision variable and applying Pinch technology simultaneously, the recoverable
black liquor could be increased by 7% and energy consumption decreased by 12%.