Catalytic pyrolysis of olive oil residue to produce synthesis gas: the effect of bulk and nano metal oxides

In this study, olive oil residue (OR) biomass was pyrolyzed in the presence of bulk MgO (B-MgO), nano-MgO (N-MgO), bulk ZnO (B-ZnO)), and nano-ZnO (N- ZnO) metal oxides at different temperatures (400, 600, and 800 ºC). Significant results were obtained in terms of synthesis gas formation and CO(2) reduction. The efficiency distribution of the products obtained as a result of the metal oxide-based pyrolysis process and the effects of metal oxides were examined in detail. Nanometal oxides were synthesized by the hydrothermal method. Characterization of metal oxides was carried out by Brunauer–Emmett–Teller (BET), x-ray powder diffraction (XRD) analysis and scanning-electron microscopy-energy dispersive x-ray (SEM-EDX) techniques. The metal concentration of OR biomass was detected via the x-ray fluorescence (XRF) technique. Tar product properties were evaluated by gas chromatography-mass spectrometry (GC-MS) and Fourier transform-infrared spectroscopy (FT-IR) analyzes. Analysis results show that pyrolytic tar is very similar to diesel and gasoline as it contains significant concentrations of aliphatic and aromatic hydrocarbons in composition. In addition, the composition of noncondensable gaseous products was determined by micro gas chromatography (micro-GC) analysis.