ABSTRACT
Activated carbon supported palladium catalysts are very attractive for the continuous fixed-bed hydrogenation of fatty acids. The development process which has been carried out has resulted in the preparation of a very active and selective catalyst with a long lifetime. Important parameters for the development of a superior catalyst are the selection of support material and catalyst reduction method. In addition to the catalyst development, various reaction conditions were investigated in order to develop the concept of a commercial process. A particular activated carbon supported palladium fixed-bed catalyst retains a high activity after more than 4300 hours on stream in a long-term test run which was carried out in order to simulate a multi-step continuous reactor cascade. The new fixed-bed process offers advantages over the currently applied discontinuous stirred-tank reactor process with supported nickel catalysts. These advantages include i) no nickel contamination of the product, ii) significantly reduced catalyst poisoning by sulphur, iii) no need for the separation of catalyst powders, and iv) no catalyst sensitivity against water. A more than 20 times higher catalyst productivity has been determined for our fixed-bed process compared to the currently applied discontinuous process. Also, a comparison of both processes revealed economic advantage for our continuous fixed-bed process.
