Pyrolysis of animal by-products provides pyro-oil that contains about 10 wt% nitrogen mainly in aliphatic compounds and virtually no sulfur. The nitrogen should be removed from the oil preferably by hydrodeni-trogenation (HDN) to obtain liquid fuel and ammonia. In order to understand the catalytic HDN processes of such bio-oils the HDN of propylamine (PA) was studied as model reaction over silica-supported Ni2P and Ni catalysts. Catalysts were prepared by H2-reduction of catalyst precursor NiO/phosphated silica gel and NiO/phosphated SBA-15 silica material and NiO/silica gel.