Catalysis of Organic..

Gőbölös and Margitfalvi 25329. Reductive Amination of Isobutanolto Diisobutylamine on Vanadium ModifiedRaney® Nickel CatalystSándor Gőbölös and József L. MargitfalviChemical Research Center, Institute of Surface Chemistry and Catalysis, H-1025Budapest, Pusztaszeri út 59-67, HungaryAbstractgobolos@chemres.huAmination of i-butanol to diisobutylamine was investigated on vanadium modifiedgranulated Raney® nickel catalyst in a fixed bed reactor. The addition of 0.5 wt.% Vto Raney® nickel improved the yield of amines and the stability of catalyst. Factorialexperimental design was used to describe the conversion of alcohol, the yield and theselectivity of secondary amine as a function of “strong” parameters, i.e. the reactiontemperature, space velocity and NH 3 /i-butanol molar ratio. Diisobutylamine wasobtained with 72% yield at 92% conversion and reaction parameters: P=13 bar,T=240°C, WHSV=1 g/g h, and molar ratios NH 3 /iBuOH= 1.7, H 2 /NH 3 = 1.9.IntroductionAmines find application as intermediates in many fields of industry and agriculture(1). Lower alkylamines are usually produced by the amination of the correspondingalcohols with ammonia. However, only scare data are available in the literature onthe preparation of isobutylamines. In the alkylation of NH 3 or amines with alcohols,Co-, Ni- or Cu-containing catalysts are mainly used (1). Nickel catalysts producemainly primary amine, however, in many applications secondary amines are needed.Diisobutylamine ((iBu) 2 NH) was obtained from i-butanol (iBuOH) and i-butylaminewith 60% yield on 20wt.%Co-5wt.%Ni/Al 2 O 3 catalyst at 200ºC (2). Supported nickelcatalysts containing 25-45 wt.% metal were active in producing (iBu) 2 NH fromiBuOH and NH 3 with 65-72% yield at 86-92% conversion, and also at 200ºC (3).In this work the effect of process parameters on the amination of iBuOH to (iBu) 2 NHwas studied over V-modified Raney® nickel. V is known to increase the yield ofamines and the stability of catalyst (4,5). Factorial experimental design was used todescribe the conversion of alcohol, and the yield and selectivity of secondary amineas a function of reaction temperature, space velocity and NH 3 /iBuOH molar ratio.Results and DiscussionThe V-modified Raney® nickel catalyst showed noticeable stability in time-onstreamexperiment for 55 h, and tolerated several heating-cooling cycles. It is