Optimization of hydrothermal liquefaction process for bio-oil products from kitchen residue under subcritical conditions

In this work, the process parameters of batch hydrothermal liquefaction of kitchen residue were optimized with the yield of bio-oil as reference, including reaction temperature, residence time and initial pressure. According to the experimental results, the bio-oil yield of kitchen residue was the highest (39.73%) under the reaction conditions of 6 MPa, 300 degrees C and 30 min. The elemental content and components of bio-oil were characterized by organic element analyzer and gas chromatography/mass spectrometer. The surface and structural properties of biochar were detected and analyzed by Fourier transform infrared spectrometer, scanning electron microscope and surface area and porosity analyzer.