Research On Production And Utilization Of Bio-oil From Biomass Fast Pyrolysis

Biomass fast pyrolysis technology is promising to realize the continuous produc tion and industrial applications,and capable to convert biomass into bio-oil that mi ght be a substitute to the liquid fuels,and thus become one of the frontier technol ogies in the world's development of renewable energy.However,various impact fac tors on pyrolysis,as well as the limitations in the direct utilization of crude bio-oil, are the primary issues that restrict the commercialization of biomass fast pyrolysis technology.On this basis,and supported by the Basic Research Program of China and National Natural Science Foundations,an integrated research on the production and utilization of bio-oil from biomass fast pyrolysis was presented in this thesis.The species of biomass feedstock influenced the distribution of liquid pyrolysis products directly.Considering the species and distribution of biomass resources in China and the economic feasibility,seven different biomass materials belonging to f our species were selected as the research objects.A series of testing methods,such as elemental and industrial analysis,compositional analysis,thermogravimetric anal ysis,thermogravimetric-Fourier transform infrared spectrometry analysis,were carried out to achieve the physical and chemical properties of different biomass materials. The pyrolysis behavior at inert atmosphere was studied,and the pyrolysis products were identified preliminarily.The influence of different spray mediums on the yield and quality of bio-oil w as investigated in a 5kg/h biomass fast pyrolysis fluidized-bed reactor.L-isopar was a perfect spray medium,which would come into different layers with bio-oil rapid ly after mixed and not impact the composition of bio-oil.Moreover the spray cond ensation improved the bio-oil yield to some extent.On the fluidized-bed pyrolysis s ystem the influence of operating conditions and the biomass species on the bio-oil yield was achieved,and the properties of the pyrolysis products were analyzed furt her.Based on the analysis of physical and chemical characteristics,the bio-oil was pre-separated by molecular distillation,and the properties of bio-oil distillates were analyzed.The physical properties and the porosity structure of biomass pyrolysis ch ar were studied.It was indicated that the char generated during biomass pyrolysis h ad the primary porosity structure,available for the production of active carbon.In the near future emulsification of bio-oil together with diesel to produce emu lsified fuels is an effective way to use bio-oil as an alternative fuel.The formulas of emulsified fuels were explored firstly by studying the emulsification of bio-oil m odel compounds.The appropriate formulas for bio-oil emulsification were determine d by further experimental research,and the influences of storing periods and collect ion ways of bio-oil on the emulsification performance were analyzed as well.Differ ent biomass pyrolysis oils were emulsified by the optimized emulsifier formula.The emulsification performance and physical-chemical properties of the emulsified fuels were analyzed.Based on the experimental results,pseudo-ternary phase diagram of the emulsified fuels was drawn,and their combustion characteristics were numerica lly simulated,which were helpful to the utilization of bio-oil emulsified fuels econo mically and the optimization of emulsifier formulas.