Pyrolysis of hazelnut shells in a fixed-bed tubular reactor: yields and structural analysis of bio-oil

Fixed-bed pyrolysis experiments have been conducted on a sample of hazelnut shells to determine the possibility of being a potential source of renewab le fuels and chemical feedstocks. The effects of pyrolysis temperature and well-sweep gas atmosphere (Nz) on the pyrolysis yields and chemical composi tions have been investigated. The maximum bio-oil yield of 23.1 wt.% was ob tained in N-2 atmosphere at a pyrolysis temperature of 500 degrees C and he ating rate of 7 K min(-1). The pyrolysis products were characterised by ele mental analysis and various chromatographic and spectroscopic techniques an d also compared with currently utilised transport fuels by simulated distil lation. Bio-oil was then fractionated into pentane soluble and insoluble co mpounds (asphaltenes). Pentane soluble was then solvent fractionated into p entane, toluene, ether and methanol subfractions by fractionated column chr omatography. The aliphatic and low-molecular-weight aromatic subfractions o f the bio-oil were then analyzed by capillary column gas-liquid chromatogra phy and GC/MS. Further structural analysis of bio-oil and aromatic and pola r subfractions FTIR and H-1-NMR spectra were obtained. The chemical charact erization has shown that the bio-oil obtained from hazelnut shells was quit e similar to the crude oil and shale oil. (C) 1999 Elsevier Science B.V. Al l rights reserved.