Separation And Upgrading Of Bio-oil

Biomass energy is the most common renewable energy. As it is friendly to the environment, it is an ideal clean energy. The effective use of biomass energy can reduce the energy consumption and environmental crises. Biomass with low energy density can be converted to high energy density liquid called bio-oil via pyrolysis. Liquid fuel plays an important part in the energy structure, and the production and application of bio-oil are very important in biomass utilization. Bio-oil can substitute fossil fuel after upgrading. In addition, extraction of high value compounds, such as acetic acid and levoglucosan in bio-oil, is also an important application of bio-oil.After a review of biomass utilization and development situation, based on the properties of bio-oil, the upgrading methods of bio-oil were compared, and the distillation and etherification technology of bio-oil were then studied.Experimental research on the pyrolysis of pine wood has been carried out on a mini fluid bed which was developed. And physical properties such as water content, viscosity, LHV, solid content and pH value were investigated. Combustion characteristics and components distribution of bio-oil were analyzed by thermo gravimetric and GC-MS. It was found that this kind of bio-oil is rich in phenols and has a high water content and pH value.Based on the component distribution and physical properties of bio-oil, it was found that bio-oil is an easily degenerate mixture and contains complicated composition. Experiments of bio-oil separation using molecular distillation technology were carried out, focusing on the influence of distillation temperature on the bio-oil components distribution. Bio-oil was divided into three fractions: liquid nitrogen condensate, room temperature condensate and residue, both liquid nitrogen condensate and room temperature condensation are distillate fractions. After GC-MS analysis, liquid nitrogen condensate contains most volatile components, and the high acidity is relate to high acids content; room temperature condensate is rich in phenols; as residue has a high content of levoglucosan.At last, upgrading research of bio-oil and liquid nitrogen condensate via esterification was carried out. In order to obtain the activity of exchange resins catalyst, Etherification of acetic acid and ethanol has been studied as a model reaction. This catalyst has a mild property and been easy to separate after esterification. Because the acid in bio-oil converted to ester after esterification, the properties of bio-oil were improved.