Abstract: Oxidative dehydrogenation of C2-C3 alkanes is an interesting alternative to the current industrial processes (steam cracking or catalytic dehydrogenation) for the olefins production. At present, the most promising results are obtained for transformation of ethane to ethylene [1] due to its lower reactivity as compared to propylene. The goal of the present study is reveal of the reaction condition effects on the performance of MoVTeNbO catalyst in oxidative conversion of ethane. Oxide catalyst with the ratio Mo:V:Te:Nb = 1:0.3:0.23:0.12 have been prepared according [2] by stepwise thermal decomposition of mixed slurry with formation of the socalled M1 and M2 phases, the first being an active one [3]. Catalytic activity has been carried out at 340-480oC and varied mole ratio O2/C2H6 = 10.00.2 in flow and flow circulating setups with on-line chromatographic analysis. Formation of reaction products is described by triangular scheme with ethylene and carbon oxides forming by parallel path from ethane and carbon oxides forming by consecutive route from ethylene as well. Under O2/C2H6  1 within 340-460oC temperature was determined does not affect the part of parallel and consecutive routes of reaction products formation, therefore at equal ethane conversion selectivity to ethylene and COx are independent of temperature. When ratio O2/C2H6 decreases up to 0.2 and reaction temperature becomes higher then 470oC catalyst deactivation is observed. Decline in catalytic activity and ethylene selectivity is conditioned by decomposition of M1 and M2 phases owing to partial elimination of Te and Mo and formation of Te-free phases – Mo5-x(V,Nb)xO14 and (Mo,V)O2 possessing insufficient catalytic properties. On the basis of the dependencies of the rates of particular reactions on reaction conditions kinetic model was proposed and kinetic parameters were estimated with the maximal deviation of the calculated and experimental reaction mixture concentrations of no more than 5.3%.

Cite: Bondareva V.M. , Lazareva E.V. , Kardash T.Y. , Ovchinnikova E.V. , Sobolev V.I.
Effect of Reaction Conditions on Ethane Oxidative Conversion over MoVTeNbO Catalyst
X International Conference “Mechanisms of Catalytic Reactions” 02-06 Oct 2016