Preparation of C10-C30-alkenes by partial hydrogenation of alkynes over fixed-bed supported palladium catalysts
申请人:——
公开号:US20010039368A1
公开(公告)日:2001-11-08
Alkenes are prepared by partial hydrogenation of alkynes in the liquid phase at from 20 to 250° C. and hydrogen partial pressures of from 0.3 to 200 bar over fixed-bed supported palladium catalysts which are obtainable by heating the support material in the air, cooling, applying a palladium compound and, if required, additionally other metal ions for doping purposes, molding and processing to give monolithic catalyst elements, by a process in which
A) alkynes of 10 to 30 carbon atoms are used as starting compounds,
B) the palladium compound and, if required, the other metal ions are applied to the support material by impregnation of the heated and cooled support material with a solution containing palladium salts and, if required, other metal ions and subsequent drying, and
C) from 10 to 2000 ppm of carbon monoxide (CO) are added to the hydrogenation gas or a corresponding amount of CO is allowed to form in the liquid phase by slight decomposition of a compound which is added to the reaction mixture and eliminates CO under the reaction conditions.
The process is particularly advantageous if the partial hydrogenation is carried out in a tube reactor by the trickle-bed or liquid phase procedure with product recycling at cross-sectional loadings of from 20 to 500 m
3 /m
2 *h. The process is particularly suitable for the preparation of 3,7,11,15-tetramethyl-1-hexadecen-3-ol (isophytol), 3,7,11-trimethyl-1-dodecen-3-ol (tetrahydronerolidol), 3,7,11-trimethyl-1,4-dodecadien-3-ol, 3,7,11-trimethyl-1,6-dodecadien-3-ol (dihydronerolidol), 3,7-dimethyloct-1,6-dien-3-ol or 3,7-dimethyloct-1-en-3-ol from the corresponding alkynes.
烯烃的制备是通过液相中的炔烃在 20 至 250 摄氏度和 0.3 至 200 巴氢气分压下,在固定床支撑的钯催化剂上进行部分氢化来实现的,钯催化剂可通过在空气中加热支撑材料,冷却,加入钯化合物,必要时加入其他金属离子进行掺杂,成型和加工,得到整体催化剂元件,其工艺过程为
A) 以 10 至 30 个碳原子的炔烃作为起始化合物、
B) 通过用含有钯盐和其他金属离子(如需要)的溶液浸渍加热和冷却后的载体 材料,并随后进行干燥,将钯化合物和其他金属离子(如需要)应用到载体材 料上,以及
C) 在氢化气体中加入 10 至 2000 ppm 的一氧化碳 (CO),或通过加入反应混合物中的化合物的轻微分解在液相中形成相应量的一氧化碳,并在反应条件下消除 CO。
如果部分氢化是在管式反应器中通过涓流床或液相程序进行的,并在横截面载荷为 20 至 500 m
3 /m
2 *h.该工艺尤其适用于制备 3,7,11,15-四甲基-1-十六烯-3-醇(异植物醇)、3,7,11-三甲基-1-十二烯-3-醇(四氢芹醇)、3,7、3,7,11-三甲基-1,4-十二烯-3-醇、3,7,11-三甲基-1,6-十二烯-3-醇(二氢芹醇)、3,7-二甲基辛-1,6-二烯-3-醇或 3,7-二甲基辛-1-烯-3-醇。