A study on pyrolysis of Canada thistle (Cirsium arvense) with titania based catalysts for bio-fuel production

The catalytic pyrolysis of Cirsium arvense was performed with titania supported catalysts under the operating conditions of 500 °C, 40 °C/min heating rate, 100 mL/min N2 flow rate in a fixed bed reactor for biofuel production. The effect of catalysts on product yields was investigated. The amount of pyrolysis products (bio-char, bio-oil, gas) and the composition of the produced bio-oils were determined by proton nuclear magnetic resonance (1H NMR), Fourier transform infrared spectroscopy (FT-IR), gas chromatography/mass spectrometry (GC-MS) and elemental analysis (EA) techniques. Thistle bio-oils had lower O/C and H/C molar ratios compared to feedstock. The highest bio-char and bio-oil yields of 29.32 wt% and 36.71 wt% were obtained in the presence of Ce/TiO2 and Ni/TiO2 catalysts respectively. GC-MS identified 97 different compounds in the bio-oils obtained from thistle pyrolysis. 1H NMR analysis showed that the bio-oils contained ∼55-77% aliphatic and ∼6-19% aromatic structural units.