Title: Assessment of thermodynamic performances for distillation columns

Authors: Yasar Demirel

Addresses: Department of Chemical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA

Abstract: This study uses the results of converged mass and energy balances and exergy loss profiles by the Aspen Plus simulator to assess the thermodynamic performances of existing continuous distillation columns. Distillation is highly irreversible and energy intensive process. Such an assessment identifies the level of exergy loss due to irreversibility, the avoidable part of exergy loss, and exergy efficiency. The case studies assessed are the separation sections of methanol and vinyl chloride monomer production plants, and a 15-component two-column system. These systems contain two columns in series, which separate multicomponent feeds, produce side products, and operate with integrated process heat streams. The results show considerable exergy losses mainly in and around the feed stage, condenser, and reboiler. The estimated avoidable parts of the exergy loss profiles and the total exergy losses help in identifying possible improvements.

Keywords: exergy losses; exergy loss profiles; exergy efficiency; potential improvement indicator; thermodynamic performances; distillation columns.

DOI: 10.1504/IJEX.2006.010229

International Journal of Exergy, 2006 Vol.3 No.4, pp.345 - 361

Published online: 11 Jul 2006 *

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