The effect on pyrolysis products of the pre-treatments applied to biomass

Biomass is converted into liquid, solid and gas products with thermochemical conversion methods. Pyrolysis is one of the thermochemical conversion methods which the raw material is transformed into new products by decomposing in oxygen-free environment at high temperature. In this study, Sinapis alba plant was used as a raw material source. Before the pyrolysis process, acidic (H2SO4, HCl), basic (NaOH, KOH) and hydrothermal (HTL) pre-treatment processes were applied to raw material. Pyrolysis experiments were carried out at 350°C, 450°C and 550°C. In total, six different samples were pyrolyzed, five of them were pre-treated and the one of them was untreated. The obtained liquid and solid products were analyzed by elemental analysis, FT-IR, GC-MS, 1H NMR, SEM analysis methods. As a result, the highest liquid product yield was observed at 350°C with %16,65 ratio for biomass which pre-treated with NaOH solution and the highest solid product yield at 350°C with %31,39 ratio was seen by raw substance. According to the elemental analysis results, the highest energy value for liquid products was found 24,039 Mj/kg in raw material, and the highest energy value for solid products was found 28,061 Mj/kg in the biomass pre-treated with NaOH solution. The aromatic, aliphatic and oxygenated compounds were detected in the obtained products, according to the GC-MS results. Keywords: Sinapis alba, Pyrolysis, Bio-oil, Biochar, Pre-treatment methods.