Impact of hot water pretreatment temperature on the pyrolysis of birch wood

•Hot water pretreatment temperature influences the treated wood composition.•TG and Py-GC/FID/MS reveal the chemical changes in wood.•Evolution of levoglucosan and lignin derived products in volatiles is presented.

Hydrothermal treatment of wood is an integral part of a modern biorefinery concept. Our research is devoted to the study of properties of birch wood and lignocelluloses at its base after hydrothermal treatment at various temperatures using TG and Py-GC/FID/MS. It was found that treatment in temperature range 150-200 °C led to increase of the content of pyrolysis volatiles due to the increase of the content of the main cellulose product-levoglucosan, while the content of the phenolic products was practically constant. Due to hydrolytic processes and condensation reactions in the temperature range 200-250 °C the content of all carbohydrate derived volatiles decreased and the content of lignin destruction products increased mainly at the expense of dimethoxylated derivatives.