| Bio-oils produced by fast pyrolysis are promising renewable energy source,which have the potential to substitue for fossil energy.However,the bio-oil needs to be further improved because of its undesired properties,such as acidity,relatively high viscosity,limited thermal stability and low heating value.In this study,the multi-step upgrading process has been proposed based on the properties of bio-oil.Furthermore,the viewpoint of comprehensive utilization of distillation residue is put forward.Firstly,the basic properties and thermal stability of bio-oil have been investigated.During an accelerated ageing process?store at 80??,the active compounds are prone to condensation reaction and form large molecules or solids,which caused the low-boiling volatiles contents of bio-oil with ageing time was evident decreased,while viscosity and water-insolubles of bio-oil have gradually increased.The results indicated that the instability of bio-oil was caused by multiple factors and synergies between active molecules and solids usually exist.Solvent–anti-solvent extraction technology?dichloromethane as solvent,water as anti-solvent?was developed to separate organic phase from bio-oil.Compared with the raw bio-oil,the modified bio-oil?extracted organic phase?had the high concentrations of phenols and the low contents of sugars and water.Then,three sets of feasible blended fuels?blend-1,blend-2 and blend-3?,devirved from the blend of bio-oil or modified bio-oil with commercial diesel and 1-butanol,were prepared through three-phase diagrams.The combustion characteristics and the combustion kinetic and thermodynamic parameters of the prepared blended fuels have been systematically investigated.The results illustrated that the 3#blended fuel?55%modified pyrolysis oil,10%diesel,35%1-butanol?with the highest combustion efficiency is recommended as burner fuel.The nickel supported on carboxylic carbon nanotubes catalysts with different diameter?Ni/CCNTs-X,X=1,2,3,4 and 5?have been synthesized via sonication-assisted impregnation approach in this work.And,the hydrogenation process and mechanism of model compound?vanillin?over Ni-based catalysts were systematically investigated.During the hydrodeoxygenation process,the transformation of vanillin to p-creosol mainly proceed via hydrogenation/hydrogenolysis path.Furthermore,the prepared Ni-based catalysts were used for catalytic hydrogenation of the modified bio-oil and compared with commercial Ru/C.The quality of modified bio-oil was improved after hydrogenation process.And the hydrogenation performance of Ni/CCNTs-4catalyst was significantly better than that of Ru/C catalyst.The comprehensive utilization of distillation residue,derived from the distillation by-product of the rice straw pyrolysis oil,has been conducted in this work.?1?The magnetic biochars were facile fabricated by thermal pyrolysis of Fe?NO3?3 and distillation residue at various temperatures.The adsorption capacity of the magnetic biochars to various aromatics?i.e.,anisole,phenol and guaiacol?were investigated carefully.The results shown that the magnetic biochar can be used as an effective adsorbent for aromatic contaminants treatment due to its strong adsorption ability.The adsorption mechanisms also have been studied.?2?The distillation residue was used to prepare the blended fuels with lignite.The significant synergistic interaction was observed during co-combustion of the blended fuels.The structure-performance relationship between the chemical structure,element composition and surface morphology of the solid blended and the combustion performance was established.Meanwhile,the combustion mechanisms and kinetic parameters were calculated by the Coats-Redfern model,suggesting the combustion reaction of lignite was enhanced by distillation residue during co-combustion. |
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