负载型磷钨酸催化剂的制备及其在甲醇汽油催化改性中的应用

以SiO2为载体、磷钨酸(PW12)为主活性物质,采用浸渍法制备了PW12/SiO2催化剂,并将该催化剂用于M15甲醇汽油中的轻质组分的催化改性;考察了PW12负载量、焙烧温度、反应温度、空速、反应压力等因素对催化剂催化性能的影响。实验结果表明,在PW12负载量(相对于SiO2的质量分数)30%、焙烧温度300℃条件下制备的催化剂的作用下,在反应温度80℃、空速2 h-1、反应压力1.0 MPa的反应条件下,催化剂的活性最高,反应后7种易挥发组分甲醇、异己烷、甲基叔丁基醚、苯、甲苯、正辛烷和对二甲苯的总质量分数及饱和蒸气压均最低,分别为29.38%和57.4 kPa。采用XRD和FTIR手段对催化剂的结构进行表征。表征结果显示,负载后PW12的部分特征吸收峰发生一定程度偏移;当PW12负载量超过30%后,XRD谱图中出现了明显的PW12特征晶相衍射峰。

Preparation of Supported Phosphotungstic Acid Catalyst and Its Application to Catalytic Modification of Methanol Gasoline

A supported phosphotungstic acid PW12 catalyst PW12/SiO2 was prepared by a pickling process and was used in catalytic modification of the light components in M15 methanol gasoline.The effects of PW12 loading,catalyst calcination temperature,reaction space velocity,reaction pressure and reaction temperature on the performance of the catalyst in the modification reactions were investigated.The results indicated that under the optimal conditions of PW12 loading 30%(based on SiO2 mass),catalyst calcination temperature 300 ℃,reaction space velocity 1 h-1,reaction pressure 1 MPa and reaction temperature 80 ℃,both the total mass fraction of the 7 light components(methanol,isohexane,methyl tert-butyl ether,benzene,toluene,octane and xylene) and the saturated vapor pressure were lowest,29.38% and 57.4 kPa respectively.The catalyst was characterized by means of XRD and FTIR,and the results showed that after PW12 was loaded,part of the infrared absorption peaks of the main active component shifted to some extent.When PW12 loading exceeded 30%,the characteristic crystalline peaks of PW12 would appear on XRD spectra.