Brassica napus L. pyrolysis experiments were performed in a Heinze reactor under static atmosphere at a pyrolysis temperature of 500 degrees C at 40 degrees C/min of heating rate. The effect of particle size on the yields of the products was investigated. The particle size of rapeseed was varied in the range of 0.224-1.8 mm. Pyrolysis oil and char yields from rapeseed were found to be largely independent of particle size in the experimental conditions. Oil yield shows a maximum of ca 46 wt% with a particle size range of 0.85-1.8 mm. The various characteristics of pyrolysis oil obtained under these conditions were identified on the basis of standard test methods. The empirical formula of pyrolysis oil with a heating value of 38.4 MJ/kg was established as CH1.67O0.12N0.046. The results from the pyrolysis of rapeseed showed the potential of rapeseed as an important source of liquid hydrocarbon fuels. Rapeseed oil was also evaluated for fatty acid composition. (C) 2000 Elsevier Science Ltd. All rights reserved.