Catalysis of Organic..

Gőbölös and Margitfalvi 255maximums in the function of NH 3 /iBuOH ratio (see also Fig. 2). Under the samecondition (t=220°C, NH 3 /iBuOH=1.4) the yield of amine is lower on the unmodifiedRaney® nickel than on the V-modified one (compare 5 th and 6 th rows in Table 2).Table 2. Amination of isobutanol. Effect of temperature and NH 3 /iBuOH ratioT, °C NH 3 /iBuOH Conversion, %Yield, % Selectivity, %(iBu) 2 NH (iBu) 2 NH200 1.1 72 53 74200 1.4 78 59 76200 2.3 82 59 72220 0.9 69 51 73220 a 1.4 88 60 68220 1.4 87 65 75220 1.7 88 67 76240 1.2 88 66 75240 1.7 92 72 78240 2.5 95 60 63Reaction condition: WHSV=1.0g/g catalyst h; P=13bar; H 2 /NH 3 =1.9a Experiment was carried out on unmodified Raney nickel.80Yield of (iBu) 2 NH, %706050400 0,5 1 1,5 2 2,5 3NH 3 /iBuOH molar ratioFigure 2. Amination of i-butanol. Effect of NH 3 /i-BuOH ratio on (iBu) 2 NH yield.Reaction condition: T=225°C;WHSV=1.0g/8g catalyst h9; H 2 /NH 3 =1.6Low NH 3 /iBuOH molar ratio is not sufficient to achieve high conversion and degreeof amination, whereas at high ratios, e.g. NH 3 /iBuOH=2.5 the selectivity of primaryamine increases at the expense of secondary one. It has been found that thetemperature, space velocity and NH 3 /iBuOH ratio strongly affect both the conversion