Determination of the activation energies of beef tallow and crude glycerin combustion using thermogravimetry


Autoria(s): Crnkovic, Paula Cristina Garcia Manoel; Koch, Christoph; Avila, Ivonete; Mortari, Daniela Andresa; Cordoba, Aymer Yeferson Maturana; Santos, Antonio Moreira dos
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

01/11/2013

01/11/2013

2012

Resumo

The present study deals with the determination of the activation energy for the thermal decomposition of two renewable fuels crude glycerin and beef tallow. The activation energies were investigated by using a thermogravimetric analyzer (TGA) in the temperature range of 25-600 degrees C in atmosphere of synthetic air. The TG curves of the thermal decomposition process of both samples were divided into several phases and the second, called PH2, was chosen for the kinetic study because it is associated with the combustion ignition. Differential Thermal Analysis (DTA) showed an endothermic event at the PH2 region for the crude glycerin corresponding to devolatilization, while for beef tallow, this step presented an exothermic event, called LTO (low-temperature oxidation), which is correlated with devolatilization followed by combustion. For the entire PH2, activation energy values for crude glycerin were between 90 kJ mol(-1) and 42 kJ mol(-1), while for the beef tallow they ranged from 50 kJ mol(-1) to 113 kJ mol (1). The activation energy values obtained at the pre-ignition stage - conversion between 0 and 0.45 - showed that the crude glycerin with higher values requires an additional energetic support at the start of combustion processes and the beef tallow ignites more easily, presenting lower values. According to the Wolfer's equation, a direct relation between the activation energy and the ignition delay is established and the results of this study provides useful data for the development and design of new combustion chambers and engines when non-traditional fuels are used as feedstock. (C) 2012 Elsevier Ltd. All rights reserved.

CAPES

CAPES [PNPD 0034088, BEX 1149/10-5]

FAPESP

FAPESP [2011/00183-2, 2011/11321-7]

Identificador

BIOMASS & BIOENERGY, OXFORD, v. 44, n. 4, supl. 1, Part 3, pp. 8-16, SEP, 2012

0961-9534

http://www.producao.usp.br/handle/BDPI/37455

10.1016/j.biombioe.2012.04.013

http://dx.doi.org/10.1016/j.biombioe.2012.04.013

Idioma(s)

eng

Publicador

PERGAMON-ELSEVIER SCIENCE LTD

OXFORD

Relação

BIOMASS & BIOENERGY

Direitos

closedAccess

Copyright PERGAMON-ELSEVIER SCIENCE LTD

Palavras-Chave #BIOFUELS #CRUDE GLYCERIN #BEEF TALLOW #KINETICS #THERMAL ANALYSIS #IGNITION DELAY #PYROLYSIS #KINETICS #FUEL #HYDROGEN #TESTS #OILS #GAS #AGRICULTURAL ENGINEERING #BIOTECHNOLOGY & APPLIED MICROBIOLOGY #ENERGY & FUELS
Tipo

article

original article

publishedVersion