Upgrading fast pyrolysis oil: Solvent–anti-solvent extraction and blending with diesel

• Solvent–anti-solvent extraction technology was developed to modify pyrolysis oil.
• Three phase charts were built to effectively prepare the homogeneous blended fuels.
• The physicochemical properties of the blended fuels have been improved compared with the pyrolysis oil.
• The blended fuel of blend-3 with the high combustion efficiency could be used as burner fuel.
• Combustion kinetic and thermodynamic parameters of blended fuels were investigated.

In order to upgrade biomass fast pyrolysis oil for excellent applications, solvent–anti-solvent extraction technology (dichloromethane as solvent, water as anti-solvent) was developed to separate organic phase from pyrolysis oil. The optimum extraction efficiency was achieved at pyrolysis oil:dichloromethane:water = 10:10:3 (volume ratio). In comparison to the raw pyrolysis oil, the modified pyrolysis oil (extracted organic phase) had the high concentrations of phenols, while the low sugars and water contents. Then, the pyrolysis oil and modified pyrolysis oil were used to prepare the homogeneous blended fuels with commercial diesel in the presence of 1-butanol by mean of three-phase charts of pyrolysis oil/diesel/1-butanol and modified pyrolysis oil/diesel/1-butanol blends. Three sets of feasible blended fuels (blend-1, blend-2 and blend-3) have been produced. And, the basic physical properties, structural characteristics, thermal degradation properties, combustion characteristics and the combustion kinetic and thermodynamic parameters (Ea, A, ΔH‡, ΔG‡ and ΔSΔS‡) of the prepared blended fuels have been systematically investigated. The physicochemical properties of the blend fuels have been improved compared with the pyrolysis oil. Meanwhile, blend-3 (55% modified pyrolysis oil, 10% diesel, 35% 1-butanol) with the highest combustion efficiency is recommended as burner fuel.