Application of laser-based diagnosis for characterization of the influence of inorganics on the slow pyrolysis of woody biomass

Publication date: Available online 9 March 2019Source: Journal of Analytical and Applied PyrolysisAuthor(s): H. Almuina-Villar, N. Lang, A. Anca-Couce, J. Röpcke, F. Behrendt, A. Dieguez-AlonsoAbstractThe influence of inorganic species content on the slow pyrolysis of thermally thick wood particles was investigated with the application of laser-based spectroscopy techniques. Infrared laser absorption and laser-induced fluorescence were used to characterize, on-line and in-situ, the release of permanent gases (CO and CH4) and the formation of species emitting fluorescence, respectively. These advanced methods were combined with the continuous monitoring of mass and temperature and with off-line GC-MS analysis of the liquid fraction. The experiments were performed using spherical particles of beech, H2O- and HCl-washed beech, KCl-doped beech and pine. The pyrolytic behavior of washed beech (with lower content in inorganic species) was found to resemble much closely the one of pine, rather than the one of beech, probably due to the pine low content in K. Both washed beech and pine showed a more clear separation between cellulose and lignin decomposition, being the lignin decomposition, and potentially the presence of heterogeneous secondary reactions, shifted to higher temperatures. The composition of the species emitting fluorescence was also affected by the removal/addition of inorganic species. K was observed to catalyze the pyrolysis reaction. A strong exothermic behavior, ...
Source: Journal of Analytical and Applied Pyrolysis - Category: Chemistry Source Type: research