A process for preparing C¶10¶-C¶30¶-alkenes by partial hydrogenation of alkynes to fixed-bed supported palladium catalysts

A process for the preparation of alkenes by partial hydrogenation of alkynes in the liquid phase at temperatures of 20 to 250 ° C and hydrogen pressures from 0.3 to 200 bar on palladium-fixed-bed support catalysts obtained by heat treatment of the support material in the air, cooling, applying a palladium compound and optionally additionally for doping purposes other metal ions, molding and processing to monolithic catalyst elements are available, which is characterized in that use is DOLLAR AA) alkynes of 10 to 30 carbon atoms, as starting compounds, DOLLAR AB) the palladium compound and optionally the other Matellionen by impregnating the annealed and cooled support material with a palladium salts and optionally other metal ions applying containing solution and subsequent drying of the carrier material and DOLLAR AC) that is added or a corresponding amount of CO the hydrogenation 10 to 2000 ppm of carbon monoxide (CO) in fluss leaves, caused by slight decomposition of an added to the reaction mixture compound which eliminates CO under the reaction conditions strength phase. DOLLAR A particularly advantageous designed, the method, when performing the partial hydrogenation in a tubular reactor in a downflow or upflow mode with product recycling at cross-sectional loadings of from 20 to 500 m 3 · · / m · 2 · * h. Particularly suitable is the method for the preparation of 3,7,11,15-tetramethyl-1-hexadecen-3-ol (isophytol), ...