Quantified monophenols in the bio-oil derived from lignin fast pyrolysis

• Feedstock of EMAL isolated from moso bamboo using enzymatic/mild acidolysis method has a higher purity and yield and chemical structure greatly reserves native lignin. Compared to industrial lignin, the higher bio-oil yield of 54.17% and more phenols of 79.34% in bio-oil were obtained.
• Alkylphenols account for a big part of monophenols, i.e. the yield based on lignin of phenol, methylphenol, ethylphenol can reach 28.47, 14.12, and 20.42 mg g−1, respectively. Furthermore, the yield bsed on lignin of guaiacol, p-methylguaiacol, vanillin was respectively 12.64, 24.84, and 15.01 mg g−1.
• The higher yield of monophenols derived from lignin depolymerization can be used either directly as bio-fuel after upgrading or as feedstock for chemicals.

The present work is dedicated to investigate the effect of pyrolysis temperature on the products distribution and the yield of monophenols producing from lignin fast pyrolysis. The bio-oils obtained at different pyrolysis temperatures were first qualitatively identified and then quantified by using external standards with mainly focus on the major monophenols. The results showed that the yield and identity of the phenolic products were strongly correlated to the pyrolysis temperature as well as the chemical structure and thermochemical properties of lignin. The highest yield of bio-oil (54.17%) was obtained at a pyrolysis temperature of 600 °C. The major individual monophenols were phenol, p-methylguaiacol, p-ethylphenol, and vanillin etc., and their associated yields (mg monophenol/g lignin) determined from the optimal pyrolysis conditions were 28.47 mg g−1, 24.84 mg g−1, 20.42 mg g−1, and 15.01 mg g−1, respectively.