Study On The Catalytic Selective Oxidation Of Methane To Methanol In Liquid Phase

The current researching of catalytic selective oxidation of methane to methanol in liquid phase at home and abroad was reviewed in this paper .The process of selective oxidation of methane to methanol in oleum was studied. The appropriate catalyst was selected and the effect of process conditions on the reaction catalysed by V2O5 and I2 was discussed. The catalytic mechanism of the reaction catalysed by V2O5 and I2 was deduced based upon the literature and experiments. The reaction rate catalysed by V2O5 was ascertained. Thermodynamic analysis on the reaction system was carried outIn the part of catalyst's evaluation, transition metals salt and oxide; various iodine compounds; hetreopolyacids, transition metals ligand complex and metallo-organic compound were studied. Among them, the best result was given by V2O5 and I2.In the part of optimizing process conditions, the influence of temperature, the amount of catalysts, reaction time and the content of SO3 in oleum was discussed respectively. For the reaction catalysed by V2O5, the reaction conditions recommended are as follows: reaction temperature 180C, amount of V2O5 0.25mol/l,reaction time 2h, the content of SO3 in oleum 50wt%. Under the optimum process conditions the conversion of CH4 is 54.4% and the yield of CH3OH is 45.5%.For the reaction catalysed by I2, the reaction conditions recommended are as follows: reaction temperature 200C,amount of I20.099mol/l,reaction time 3h, the content of SO3 in oleum 50wt%.Under the optimum process conditions the conversion of CH4 is 82.7% and the yield of CH3OH is 70.5%.In the study of catalytic mechanism, free radical mechanism was denied through the experiment, and the electrophilic alternative mechanism was suggested. The catalytic mechanism of the reaction catalysed by V2O5 and I2 was deduced based upon the literature and experimentAnalyzing the pressure-time relationship of the reaction catalysed by V2O5 gived well-defined information about the reaction rate and indicated a first- order reaction.In the thermodynamic analysis on the reaction system, the possible reactions of the "methane-oleum" system were calculated and several conclusions were drawn.Cao Kai (Chemical Engineering) Directed by associate professor Zhang Xiucheng...