The present invention relates to a method of deoxygenating tall oil pitch, yielding aliphatic and aromatic hydrocarbons. The invention even comprises turning the aliphates into polymerizable olefins by steam cracking, and turning the aromates into polymerizable terephthalic acid by oxygenation and, as necessary, rearrangement. The monomers can be used for the production of polymers of partially or completely biologic origin. According to the invention, tall oil pitch is first heated to turn it into liquid, which is then fed into a catalyst bed and catalytically deoxygenated with hydrogen. The deoxygenation catalyst is preferably a Ni—Mo catalyst and, in addition, a cracking catalyst can be used, such as an acidic zeolite catalyst. The deoxygenated product stream is cooled down so as to obtain a liquid, which is distilled for separation of the aliphatic and aromatic hydrocarbons for use in the production of the respective monomers and finally polymers.