Biomass in the form of pine bark (Pinus brutia Ten.) was pyrolysed in an externally heated fixed-bed reactor. The effects of temperature and heating rate on the yields and compositions of the products were investigated. Pyrolysis runs were performed using reactor temperatures between 300 and 500 degreesC with heating rates of 7 and 40 degreesC min(-1). The product yields were significantly influenced by the process conditions. The bio-oil obtained at 450 degreesC, at which the liquid product yield was maximum, was analysed. It was characterized by Fourier transform infrared spectroscopy. In addition, the solid and liquid products were analysed to determine their elemental composition and calorific value. Chemical fractionation of bio-oil showed that only low quantities of hydrocarbons were present. while oxygenated and polar fractions dominated. The empirical formula of the bio-oil with heating value of 31.03 MJ kg(-1) was established as CH1.43O0.332N0.0013. (C) 2003 Elsevier Science Ltd. All rights reserved.