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ISRN Thermodynamics
Volume 2012 (2012), Article ID 672691, 8 pages
http://dx.doi.org/10.5402/2012/672691
Research Article

Thermodynamic Analysis of the Hydrogen Production from Ethanol: First and Second Laws Approaches

1Chemical Engineering Department, Central University of Las Villas, Carretera a Camajuaní Km 5 y 1/2, Santa Clara, 54830 Villa Clara, Cuba
2Research Group ENVOC, Ghent University, Coupure Links 653, 9000 Ghent, Belgium

Received 6 December 2011; Accepted 7 January 2012

Academic Editors: A. Ghoufi and P. Li

Copyright © 2012 Yannay Casas-Ledón et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A thermodynamic analysis of hydrogen production from ethanol steam reforming (ESR) is carried out in the present paper. The influence of reactants molar ratio feed into the reforming stage ( 2 . 5 < m o l W a t e r / m o l E t O H < 8 ), temperature (573 to 1173 K) and pressure ( 1 < 𝑃 < 1 0 atm) over equilibrium compositions is studied. The direct method employed to analyze the system is the minimization of Gibbs free energy (MGFE) in conjunction with Lee-Kesler state equation, using the Kay mixing rules. The temperature and reactants molar ratio showed a positive influence on the hydrogen yield; ethanol conversion is 100% for the whole interval analyzed while the pressure affected greatly the hydrogen production. The carbon deposition exhibits a maximum value at temperatures around 773 K, and three reactions are proposed to describe the solid carbon formation in a wide temperature range based on thermodynamics and experimental predictions. The conditioning stages (mixing, vaporization, and heating) are studied in addition to the reaction to analyze the system quality by means of an exergetic method applying the 2nd law of thermodynamic.