Pyrolytic and hydrogenolytic degradation studies on lignocellulosics,pulps and lignins

Wood and MWL's from beech, spruce, bamboo as well as teak wood and teak-HCl-lignin were subjected to analytical pyrolysis (Py), using the off-line approach, and to hydrogenolysis (Hy). Gas chromatography-mass spectrometry (GCMS) was used for product identification and assignment as derivatives from 4-hydroxy-phenyl-propane, guaiacylpropane and syringylpropane basic units followed by capillary gas chromatography (GC) for quantitative determination of the phenolics. The results are compared with those of nitrobenzene oxidation and quantitative FTIR-spectroscopy. Py-GC and Hy-GC experiments were also used for the characterization of residual lignins in kraft and alkaline-sulphite-anthraquinone-methanol (ASAM) pulps from beech, pine and sugar cane bagasse. Analytical pyrolysis of biomass, both in on-line and off-line approach, is well suitable for lignin classification even without previous lignin isolation. Hydrogenolysis is more recommendable for the characterization of residual lignins in pulps.