Thermal synthesis and pyrolysis of a xylan

Study on the pyrolytic behaviour of xylan-based hemicellulose using TG–FTIR and Py–GC–FTIR

“…7a presents that the formation of 1,4-anhydro-D-xylopyranose is mainly attributed to the cleavage of the glycosidic linkage of the xylan chain, followed by the rearrangement of the depolymerized molecules. It is reported that the 1,4 intramolecular glycosidic bond on the xylopyranose is less stable than the 1,6 glycosidic bond on the glucopyranose (levoglucose) [20]. This implies that most of the produced 1,4-anhydro-D-xylopyranose would be instantly consumed to produce the two-carbon, three-carbon fragments and gases through the pathways (2), (3), (4), (5) and (6) in Fig.…”

“…It is difficult to separate the chemical reactions in the two peaks. The decomposition of xylan units would move forward with the elevated heating rate, enhancing the mass loss in the first peak [20]. Thus it is sensible that the first peak is much lower than the second one at the low heating rate (3 K/min).…”

“…This indicates that the CO and methanol are mainly volatilized around the first peak of the sharp mass loss stage, while the second peak is essentially ascribed to the evolution of CO 2 , aldehyde-type and acetic products. The formation of methanol should be assigned to the O-methyl group lined to the C 4 position of the glucuronic acid unit, while the evolution of CO is attributed to the decarbonylation reactions [20]. The CO 2 and acetic acid are evolved through the whole ''sharp mass loss stage'', mainly due to the cleavage of the acetyl groups from the xylan chain.…”

“…The distribution of the main products (gas, bio-oil and char) for the pyrolysis of hemicellulose has been investigated using the fixed-bed pyrolysis reactors [19][20][21] while very limited experimental studies are available for growing important fluidized bed reactor systems. The yield of typical compounds in bio-oil is discussed by Hosoya [21].…”

Relationships between Biomass Composition and Liquid Products Formed via Pyrolysis

“…However, secondary reactions occur during the pyrolysis process involving other components present within the biomass (Ponder and Richards, 1991;Kleen and Gellerstedt, 1995;Muller-Hagedorn et al, 2003;Fahmi et al, 2007;Patwardhan et al, 2010;Ronsse et al, 2012;Lou et al, 2013;Mante et al, 2014). As products form, they can interact with catalytic minerals in the residual solid.…”