Catalysis of Organic..

Gőbölös and Margitfalvi 257Y=421.79-1.676T-268.1n-245.1w+1.265Tn+1.099Tw+106.1nw-0.511Tnw(Maximum of Y=76.1%, T-240ºC, n=2.0, w=1.0g/g h) (t=95%, F=95%)The t-test for individual parameters showed that all three parameters weresignificantly different from zero within 90 or 95% confidence level. F-statistic at95% significance indicates the fit between calculated and experimental data. Thecoefficients of the equations describing the conversion, end the yield and selectivityof secondary amine indicate strong interaction between the temperature and thespace velocity and the temperature and NH 3 /iBuOH ratio. With respect to theconversion the strength of parameters is roughly equal. The strength of parameters indetermining (iBu) 2 NH selectivity decreases in the order: n > w > T. The yield ofsecondary amine is strongly influenced by all three parameters. The maximumvalues of conversion, selectivity and yield calculated by using derived equations, aswell as related reaction parameters are given in parentheses. With respect to themaximum selectivity and yield of (iBu) 2 NH the measured and calculated values arein quite good agreement.Experimental SectionThe granulated Raney® nickel catalyst was prepared by leaching a 50wt.% Ni-Alalloy with 20wt.% NaOH-H 2 O solution at 50°C as described elsewhere (8).Modification of Raney® nickel catalyst with 0.5 wt.% V was carried out byadsorption using an aqueous solution of NH 4 VO 3 (3). Catalytic test was carried outin a continuous-flow fixed bed reactor charged with 20g granulated Raney® nickelcatalyst. Prior to activity test the catalyst was heated to 250°C at a rate of 2°C/min ina flow of 75%H 2 -25%N 2 mixture and kept at 250°C for 3 hours. Liquid organicreaction product was analyzed by gas chromatography using FID and a glass column(3m x 3mm) filled with 60/80 mesh Chromosorb P NAW containing 5wt.% KOHand 18wt.% Carbowax 20M. Factorial experimental design (6,7) was applied toexplore the effect of temperature (T), weight hour space velocity (WHSV) andNH 3 /iBuOH molar ratio on the catalytic performance of V-modified Raney® nickel.References1. K. S. Hayes, Appl. Catal. A, 221, 187 (2001).2. A. Buzas, C. Fogarasan, N. Ticusan, S. Serban, I. Krezsek and L. Ilies, Ger.Offen. 2,937,325 (1981).3. M. Deeba, U.S. Patent 4,918,234 to Air Products (1990).4. J. Antal, J. Margitfalvi, S. Göbölös et al.., Hung. Patent 206,667 to NitrogenWorks Pét, Hungary (1987).5. S. Göbölös, M. Hegedűs, E. Tálas, J.L. Margitfalvi, Stud. Surf. Sci. Catal. Vol.108, Elsevier, Amsterdam, pp. 131-138 19976. G.E.P. Box and K.B. Wilson, J. Royal Statist. Soc., Ser.B 13, 1-45 (1951).S.7. A. Dey and R. Mukerjee, Fractional Factorial Planes, Wiley, N.Y. 1999.8. Gőbölös, E. Tálas, M. Hegedűs, J.L. Margitfalvi, J.Ryczkowski, Stud. Surf. Sci.Catal. Vol. 59, Elsevier, Amsterdam, 1991, pp. 335-342