甲醇脱水合成二甲醚的Al2O3-HZSM-5组合固体酸催化剂(英文)  

Synthesis of Dimethyl Ether via Methanol Dehydration over Combined Al_2O_3-HZSM-5 Solid Acids

作　　者：张立伟[1] 王军华[1] 吴佩[1] 侯昭胤[1] 费金华[1] 郑小明[1] 

机构地区：[1]浙江大学化学系,浙江杭州310028

出　　处：《催化学报》2010年第8期987-992,共6页

基　　金：Supported by the National Basic Research Program of China (973 Program,2007CB210207 and 2007AA05Z415);the National Natural Science Foundation of China (90610002);the Zhejiang Provincial Natural Science Foundation (Z406142)

摘　　要：制备了可用于固定床反应器中甲醇脱水制备二甲醚的Al2O3-HZSM-5组合固体酸催化剂系列,并采用X射线衍射、扫描电镜、N2物理吸附和氨气程序升温脱附等对其进行了表征.结果表明,在浸渍法制备的组合Al2O3-HZSM-5催化剂中,细小的氧化铝颗粒高度分散在HZSM-5分子筛的周围;在化学沉淀法制备的组合Al2O3-HZSM-5催化剂中,一层氧化铝膜覆盖在HZSM-5分子筛的颗粒外层.所制备的催化剂都具有较多的大孔和介孔比表面积,在低温(235oC)和高空速(30h-1)条件下具有较高的甲醇脱水反应活性和稳定性,其中在化学沉淀法制备的组合Al2O3-HZSM-5催化剂上,二甲醚产率达到13.5g/(g·h).Combined Al2O3-HZSM-5 solid acids were prepared and used for methanol dehydration to dimethyl ether （DME） in a fixed-bed reactor.The physicochemical properties of the combined solid acids were characterized by X-ray diffraction,field emission scanning electron microscopy,N2 adsorption,and NH3 temperature-programmed desorption.Al2O3 was highly dispersed in Al2O3-HZSM-5 after impregnation （Al2O3-HZSM-5-IM）,while a layered Al2O3-covered HZSM-5 structure solid acid was synthesized via chemical precipitation （Al2O3-HZSM-5-CP）.Both the combined Al2O3-HZSM-5 solid acids prepared by impregnation and chemical precipitation have a higher surface area and more meso-and macropores.The combined Al2O3-HZSM-5 solid acids exhibit higher methanol dehydration activity than pure Al2O3 and it possesses higher stability than pure HZSM-5 at a lower temperature （235 °C） and a higher LHSV （30 h？1）.The stable DME productivities for Al2O3-HZSM-5-IM and Al2O3-HZSM-5-CP at 235 °C reached 12.7 and 13.5 g/（g·h）,respectively.

关 键 词：组合固体酸 氧化铝 HZSM-5 甲醇 二甲醚 

分 类 号：TQ223.24[化学工程—有机化工]