| abstract |
In the production of aliphatic alpha ,w-aminonitriles (I) by catalytic partial hydrogenation of aliphatic alpha ,w-dinitriles (II), the catalyst contains: (a) iron (Fe) and/or Fe compound(s); (b) 0.01-5 wt.%, with respect to (a), of a promoter based on group 2, 3, 4 or 5 elements selected from aluminium, silicon, zirconium, titanium and vanadium; and (c) 0-0.5 wt.%, with respect to (a), of an alkali(ne earth) metal compound. Preferably component (a) is based on Fe oxide(s) and (b) on Al, Si and V. The catalyst is optionally supported. Simultaneous production of ACN and HMD from ADN comprises: (1) catalytic partial hydrogenation of ADN to a mixture containing ACN, HMD and ADN; (2) separation of ACN and HMD from the mixture; (3) adding an acid or acid ion exchanger to the mixture containing ADN especially in an amount of 0.01-10 wt.% with respect to ADN, ADN is then separated. If ADN is separated by distillation, the acid used has a boiling point above that of ADN at the pressure used for distillation and a pKa value \} 10. The purified ADN is then recycled. Hydrogenation may be carried out in a suspension or stationary bed reactor. |