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Title
Wheat straw pyrolysis analysis by thermogravimetry and gas chromatography-mass spectrometry
Authors
Qing Yang and Shubin Wu
Received
November 20, 2008
Published
Volume 43 Issue 4-6 April-June
Keywords
wheat straw, thermogravimetry, kinetics, Py-GC-MS, catalyst, pyrolysis
Abstract
The effect of the heating rates and the existence of a Ni-catalyst on the thermogravimetric characteristics of wheat straw were investigated by thermogravimetry and gas chromatography–mass spectrometry. The weight loss of wheat straw was not markedly influenced by the heating rates, over a temperature range from 220.6 to 391.2 °C, although, to obtain the same weight loss, the corresponding temperature was increased and the heating rates were enhanced. The thermogravimetric kinetic parameters of wheat straw were calculated both without catalyst and with 0.5% Ni-catalyst, by the method of Kissinger; the apparent activation energy values of wheat straw were of 93.92 and 119.80 KJ·mol-1, and the frequency factors lnA were of 17.82 and 23.02 min-1, respectively. The weight loss of wheat straw was not markedly influenced by the Ni-catalyst, while pyrolysis–gas chromatography–mass spectrometry (Py-GC-MS) evidenced that, at 800 °C, the presence of the catalyst influenced the peak intensities derived from cellulose, hemicellulose and lignin. It was concluded that the Ni-catalyst favors a more catalytic effect on wheat straw lignin, that is, the total value of the peak area from phenolic compounds and vanillin was higher than that from furfural and levoglucosan.
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