Kinetics of cellulose pyrolysis modelled by three consecutive first-order reactions

• Type: Article in International Scientific Journal
• Date: 1989

Authors

S. S. Alves (Author) Other; José Luís Figueiredo (Author) FEUP

Journal

Title: Journal of Analytical and Applied Pyrolysis

Vol. 17

Pages: 37-46

ISSN: 0165-2370

Publisher: Elsevier

Indexing

Scopus - 28 Citations

Other information

Authenticus ID: P-00F-GMZ

DOI: 10.1016/0165-2370(89)85004-1

Abstract (EN): Isothermal thermogravimetry can be used to help elucidate complex reaction mechanisms, particularly if data are represented as 'DMM plots', i.e., as - dM¿/dt vs. M¿, where M¿ is dimensionless mass and t is time. In a previous work it was shown that the simplest homogeneous reaction scheme consistent with the DMM curves of cellulose pyrolysis consists of three consecutive first-order reactions. In this work it is further shown that other mechanisms, such as nucleation and growth (Avrami-Erofeev equation) and diffusion, are also inconsistent with the experimental DMM curves. The experimental isothermal temperature range of the previous work is extended up to around 350°C to allow the calculation of the kinetic parameters of each of the three consecutive reactions. The stoichiometric parameters obtained by optimization for each of the reactions confirm former conclusions: the first reaction releases some volatile matter; the second reaction releases practically no volatiles, probably consisting of a rearrangement or activation of the solid; the third reaction releases most of the total volatile matter. Activation energies obtained vary between 139 and 209 kJ/mol. © 1989.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10