Modeling of fast pyrolysis of wood for prediction of bio-oil composition

In this work, a mathematical model is introduced that simultaneously solves the mass and energy balance of the fast pyrolysis process. For the yield calculation, the model uses starting values obtained from the literature. The mass balance is matched by introducing polycyclic aromatic hydrocarbon compounds, which are minimised by applying an optimisation algorithm. Earlier work suggested that pyrolysis oil compounds with lower oxygen content should be introduced in order to reduce the amount of the polycyclic aromatic hydrocarbon compounds required to solve the mass balance. In this work, we compare the effect of substituting glucose with levoglucosan on the calculated pyrolysis oil composition. Levoglucosan has lower oxygen content in comparison to glucose. Furthermore, we force the model to calculate higher, more realistic water contents for the pyrolysis oil. The model provides valid mass and energy balances within a certain range of heat of reactions. The model indicates that the fast pyrolysis reaction can be either exo- or endothermic. By varying the sugar species and the water content, we could conclude, that more lower oxygenated compounds should be used in order to better represent the composition of the pyrolysis oil. However, for many of those compounds, thermophysical data is not yet available and we suggest that further experimental work on the determination of thermophysical properties of pyrolysis oil components should focus on low-oxygenated phenols, acids, sugars, and aldehydes.