PYROLYSIS OF ISOCHRYSIS MICROALGAE WITH METAL OXIDE CATALYSTS FOR BIO-OIL PRODUCTION

Pyrolysis of Isochrysis microalgae was carried out in a fixed-bed reactor without and with metal oxide catalysts (CeO 2 , TiO 2 , Al 2 O 3 ) at the temperatures of 450, 500 and 550 o C with a constant heating rate of 40 o C/min. The pyrolysis conditions including catalyst and temperature were studied in terms of their effects on the yields of pyrolysis products and quality. The amount of bio-char, bio-oil and gas products was calculated. The composition of the produced bio-oils was determined by Elemental analysis (EA), Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance ( 1 H NMR) and Gas chromatography/mass spectrometry (GC–MS) techniques. As a result of the pyrolysis experiments, it is shown that there have been significant effects of both catalyst and temperature on the conversion of Isochrysis microalgae into solid, liquid (bio-oil) and gas products. The highest bio-oil yield (24.30 %) including aqueous phase was obtained in the presence of TiO 2 (50%) as catalyst at 500 °C. 98 different compounds were identified by GC-MS in bio-oils obtained at 500 o C. According to 1 H NMR analysis, bio-oils contained ∼60-64 % aliphatic and ∼17-19 % aromatic structural units. EA showed that the bio-oils contained ∼66-69 % C and having 31-34 MJ/kg higher heating values.