Chemical properties of bio-oils produced by fast pyrolysis of bamboo

Abstract

Bamboo powder was analytically pyrolyzed using pyrolysis-gas chromatography (Py-GC), and the effects of fast pyrolysis conditions on the product distribution of bio-oil were evaluated. 4-Vinylphenol (4VP) was identified as a major product of bamboo fast pyrolysis by 1 H-NMR and 13 C-NMR spectrometry. The formation pathway of 4VP demonstrated that p-coumarate esters are present in bamboo lignin, and 4VP is likely to be derived from these p-coumarate structures. The evaluation of the effect of fast pyrolysis temperature on the product distribution of bio-oil revealed that increasing pyrolysis temperature resulted in high yields of compounds containing a furan structure and reduced yields of phenolic compounds, except catechol. The fast pyrolysis of Klason lignin produced 4VP in lower yield than that from bamboo powder, even though the yield of 4-vinylguaiacol from acid lignin was greater than that from bamboo powder. In comparison with fast pyrolysis, slow pyrolysis of bamboo produced simple phenols, such as phenol, guaiacol, methyl guaiacol, syringol, and methyl syringol, in higher yields, whereas the yield of 4VP was lower than that from fast pyrolysis. The chemical characteristics of bio-oil depend on the biomass source, pyrolysis conditions, and the type of pyrolyzer.