Production of monomeric phenols by thermochemical conversion of biomass: areview

Citation
C. Amen-chen et al., Production of monomeric phenols by thermochemical conversion of biomass: areview, BIORES TECH, 79(3), 2001, pp. 277-299
Citations number
96
Language
INGLESE
art.tipo
Review
Categorie Soggetti
Biotecnology & Applied Microbiology
Journal title
BIORESOURCE TECHNOLOGY
ISSN journal
0960-8524 → ACNP
Volume
79
Issue
3
Year of publication
2001
Pages
277 - 299
Database
ISI
SICI code
0960-8524(200109)79:3<277:POMPBT>2.0.ZU;2-D
Abstract
Biomass is a renewable and alternative source for the production of fuels a nd chemicals. This paper provides a brief survey of lignin precursors as we ll as thermogravimetric and pyrolysis studies of lignin with special refere nce to the production of phenols. Thermogravimetric analysis provides infor mation on pyrolysis kinetics while thermogravimetry in combination with mas s or infrared spectrometers allowed a rapid characterization of the vapours produced by thermal treatment. Pyrolysis enabled even greater insight into the thermal behaviour of lignin. Pyrolysis of single, dimeric and trimeric model lignin compounds can determ ine the thermal stability of the intermediate compounds formed and the orig in of the pyrolysis products. A free radical mechanism has been suggested a s a major route during the early lignin degradation stages followed by a co mbined free radical and concerted pathway at elevated temperatures. Pyrolys is of lignin in the presence of catalysts as additives was investigated. Si gnificant differences in terms of yields of pyrolysis products and phenolic compounds were observed. The addition of salts resulted in a high weight l oss at low temperature and yielded more char than untreated wood. Some meta l catalysts such as transition metals and metal oxides such as Fe2O3 and Cu exhibited a better activity in terms of selectivity for the degradation of lignin. (C) 2001 Elsevier Science Ltd. All rights reserved.