III International Conference

PP-II-133THE EFFECT OF THE SUPPORT ON THE PERFORMANCE OF Со/СоAl x O yCATALYST IN FISCHER-TROPSCH SYNTHESISSvidersky S.A., Mikhailova Y.V., Sineva L.V., Mishin I.V. 1 , Mikhailov M.N., Krylova A.Y.United Research and Development Centre, Moscow, Russia1 N.D. Zelinsky Institute of organic chemistry RAS, Moscow, RussiaE-mail: SviderskySA@yrd.ruFischer-Tropsch synthesis is a complex catalytic process that includes many successiveand competing reactions and leads to formation of a various hydrocarbons from syn-gas.Heavy hydrocarbons are preferably formed in the presence of Со based catalysts. Catalyticproperties of such systems depend on the support phase composition, which is determined bythe nature of initial compounds and preparation conditions. Alumina based Со-catalysts areefficient in producing heavy hydrocarbons with undesirably high methane formation. Tocombine high yields of heavy hydrocarbons with low selectivity to methane the mixed oxidebased Со catalysts were developed. The present work is aimed at the investigation ofinfluence of Со/СоAl x O y catalyst support on yield and selectivity to high molecular weighthydrocarbons formed from СО and Н 2 . Catalytic results are supplemented by the XRD studyof phase composition of СоAl x O y support and 20%Со/СоAl x O y catalysts.The СоAl x O y support was prepared by calcining mechanical mixture of cobalt precursor(nitrate, acetate, basic carbonate, oxide) with aluminum hydroxide. The 20%Со/СоAl x O ycatalysts was prepared by double impregnation of support by Co(NO 3 ) 2·6H 2 O water solution.Hydrocarbon synthesis was carried out in fixed-bed catalytic reactor at atmospheric pressure.Before synthesis all samples were pre-reduced in hydrogen flow.The XRD study showed that the nature of cobalt precursor and aluminum hydroxide(gibbsite, boehmite, bayerite) influenced sample phase composition. In particular, boehmitebased samples contain much more γ-Al 2 O 3 , than gibbsite based support, in which most ofalumina occurs as amorphous phase. For all samples the main spinel phase detected wasСo 2 AlO 4 . Results obtained by XRD correlate with catalytic data described below.Catalytic tests confirmed that cobalt precursor nature in 20%Со/СоAl x O y catalyst supporthas an influence on yield and selectivity to С 5+ hydrocarbons. The С 5+ hydrocarbons yieldvaried in a row: basic carbonate (127 g/m 3 ) > nitrate (110 g/m 3 ) > acetate (97 g/m 3 ) > oxide(83 g/m 3 ). The highest С 5+ hydrocarbons selectivity was also reached for cobalt basiccarbonate containing sample (91% vs. 84-85% for other catalysts). It should be noted that all407