Thermal cracking of rapeseed oil under isothermal reactive distillation conditions allows the production of alternative liquid fuels. Temporal changes of the sump phase and the oil condensate show an increased higher heating value due to deoxygenation. The sump phase also shows an increasing thermal stability, accompanied by polymerization and aromatization. This is derived from a changing iodine value, H/C ratio as well as viscosity. The deoxygenation of the oil condensate is confirmed by a decreasing acid value and the reduction of detected carboxylic acids.