Application And Characterization Of Supported Phosphotungstic Acid In The Catalytic Modification For M15 Methanol Gasoline

The pressure on energy resources could be released and the dependence on petroleum inour country could be effectively reduced by the application of methanol gasoline which iscompounded with methanol and gasoline. But the most widely used M15 methanol gasoline ishighly volatile which could lead to a high saturated vapor pressure and thus it is easy to causethe problem of air resistance on automobile and the fuelling facilities. The saturated vaporpressure of M15 methanol gasoline could be reduced and the air resistance phenomenon couldbe eliminated or improved by the methanol gasoline catalytic modification technology(namely performing a catalytic reaction for the distilled light component of methanol gasolinein the presence of catalyst), in this way, the amount of main highly volatile component will beconverted and reduced. Supported phosphotungstic acid possesses a high catalytic activity forthe etherification and alkylation of catalytic modification for methanol gasoline. So supportedphosphotungsitc acid is choosed to conduct the catalytic modification for the light componentin M15 methanol gasoline, in this way, the saturated vapor pressure will be reduced and theresisitance phenomenon will be improved.The effect of catalytic modification will be analyzed and evaluated by the method of gaschromatography and saturated vapor pressure determination. And through the orthogonal testsand single-factor test, the technological condition of catalytic modification of supportedphosphotungstic acid catalyst for the light component in M15 methanol gasoline isdetermined as: reaction temperature 85℃, airspeed 1.0h-1and pressure 1.25MPa.The different effect of catalytic modification caused by different preparation conditionswill be examined and the best preparation condition of supported phosphotungstic sodium is determined as: loading 30% and calcination temperature 300℃. Compared with activedcarbon and neutral alumina, the supported phosphotungstic acid with silica as the carrierpossesses a better effect in the catalytic modification for M15 methanol gasoline.Carrier is modified with co-catalysts such as zinc, lanthanum, zirconium and cobalt, andthe effects of catalytic modification of these modified supported phosphotungstic acid catalystfor the light component in M15 methanol gasoline are different. And the best catalytic effectappears with the supported phosphotungstic acid catalyst modified with lanthanum which isprepared under the optional conditions of lanthanum loading 3% and carrier modifiedcalcination temperature 550℃. Compared with the supported phosphotungstic acid catalyst,D002 resin and KRM-30 resin, for M15 methanol gasoline which is modified by this kind ofcatalyst, its saturated vapor pressure is lower and by the testing, its quality is proved to becorresponding with the local standards of Shanxi Province.FT-IR, XRD, NH3-TPD, BET are employed to characterize, and the results show thatphosphotungstic acid interacts with the silica. The disperse degree of phosphotungstic acid onthe carrier is affected directly by the loading amount and calcination temperature ofphosphotungstic acid. The supported phosphotungstic acid catalyst still keeps the largespecific surface area and mesoporous when the loading amount is 30%.