abstracts - Институт катализа им. Г.К. Борескова

OP-I-35monoxide adsorption and hydrogenation of surface carbon species. At these conditionsoxygen-containing species are the most abundant surface intermediates.Steady-state kinetics in a slurry reactor. Preliminary experiments showed the absenceof external (gas-liquid) and intraparticle mass transfer limitations in the slurry stirred tankreactor at the conditions of FT synthesis. The rates of carbon monoxide conversion andhydrocarbon production were calculated from inlet and outlet mass flows. The chemicalcompositions of the liquid and gaseous phase were obtained from flash calculations, whichare based on the equal fugaicities of each component in gaseous and liquid phases.Depending on the experimental conditions, the time required to attain the steady-statestate varied between 11 and 25 days. The experimental data show higher carbon monoxideconversion and higher methane selectivity at higher H 2 /CO ratios. For syngas with H 2 /COratios between 1.6 and 3.6, the selectivity plots exhibit different deviations from the ASFdistributions. The olefin to paraffin ratio decreases exponentially as a function of carbonnumber.The experimental data have been fitted using the comprehensive kinetic model. Thereaction pathways involved hydrogen and carbon monoxide chemisorption, carbon monoxidedissociation, polymerization of CH x species, olefin readsorption and hydrogenation. Themodel adequately predicts the experimental relations between the carbon monoxideconversion rates and chemical composition of the liquid phase. The model also foresees theexperimentally observed deviations from the ASF distribution at different H 2 /CO ratios,which are due to olefin readsorption and chain reinitiation. The prediction of the rates ofhigher olefin production was less satisfactory. This could be probably attributed to the verylow concentrations of higher olefins and the presence of different products of theirisomerization.AcknowledgementThe financial support of Air Liquide is gratefully acknowledged.References:1 M. Bremaud, P. Fongarland, J. Anfray, S. Jallais, D. Schweich and A.Y. Khodakov,Catalysis Today, 106(2005), 137.2 H. Kobayashi and M. Kobayashi, Catal.Rev.-Sci.Eng. 10(1974) 139.3 A. Hinz, B. Nilsson and A. Andresson, Chem.Eng.Sci. 55(2000) 4385.162