Gasoline and gaseous hydrocarbons from fatty acids via catalytic cracking

The conversion of palmitic and oleic acid as well as tall oil fatty acid was investigated in a fully continuous small scale fluid catalytic cracking (FCC) pilot plant. A conventional FCC zeolite catalyst was used. Experiments were performed in the range of 485–550°C. The highest gasoline yield of 44 wt.% was obtained from oleic acid at 550°C. Palmitic acid yielded the most cracking gas at 550°C with 43.9 wt.%. The obtained gasoline was practically oxygen-free at high octane numbers. Oxygen contained in the feed was mainly converted to water and small amounts of CO₂. Gasoline aromaticity clearly increased with temperature. The formation of high boiling products was enhanced by the number of C=C double bonds in the fatty acids. Large amounts of propene and ethene were formed which are valuable reactants for the polymer industry. The lower price of fatty acids in comparison with fresh vegetable oils makes them an interesting feedstock for the FCC process.