Selective hydrogenation of sunflower oil over noble metal catalysts

Abstract

Selective hydrogenation of sunflower oil was tested using a variety of heterogeneous catalysts. The reaction was carried out in a batch reactor under different operating conditions. Palladium and platinum supported on Al 2O 3, ZrO 2 and TiO 2 were screened. A range of metal dispersions (6–69%) and loadings (0.3–3.9%) were studied for promotion of selectivity in cis C 18:1. The catalysts were compared with a conventional Ni catalyst. The Pd catalysts were found to be much more active than the Ni catalyst. The Pt catalyst, while not as active as the Pd catalysts, produced lower trans fatty acids during hydrogenation. The level of trans could be further reduced by increasing the operating pressure to 10 bar and reducing the reaction temperature to 100 °C. The reduction in trans formation was most significant for the Pt based catalyst. The different catalysts prepared were shown to process a wide variety of different characteristics in terms of metal dispersion, surface areas, particle size, etc. However, this had little influence on the overall activity of the samples. The key issue in terms of activity was the catalyst metal content.