文摘
In this study, the storage stability of bio-oil was investigated for periods of 1, 2, 4, and 8 weeks at a temperature of 23 °C. Four kinds of bio-oil from biomass with different inorganic content controlled by impregnation process, i.e., yellow poplar (YP), demineralized YP (D-YP), K-impregnated YP (K-YP), and Mg-impregnated YP (Mg-YP), were subjected to aging. During aging, the elemental composition, water content, and total acid number of bio-oil were consistent. On the other hand, viscosity, average molecular weight, and solid content of bio-oil largely increased. The amount of aldehydes and ketones significantly decreased for K-YP and Mg-YP, while that of levoglucosan significantly decreased for D-YP oil. Most of the inorganic elements were highly concentrated in a solid form in bio-oil. The leaching test revealed that inorganic species tend to leach from the solid to the liquid phase during the initial storage period. However, the overall behavior slightly fluctuated over the whole period.