Zn/Al复合氧化物催化剂结构特性及其酯交换催化活性  

The Structure of Zn/Al Complex Oxides and Their Catalytic Activity to the Transesterification in Biodiesel Production

作　　者：齐涛[1] 鲁厚芳[1] 蒋炜[1] 梁斌[1] 

机构地区：[1]四川大学化工学院,四川成都610065

出　　处：《化学反应工程与工艺》2009年第1期52-58,共7页Chemical Reaction Engineering and Technology

基　　金：教育部科学技术研究重大项目资助(307023)

摘　　要：采用共沉淀法制备系列Zn/Al水滑石前驱体,经煅烧制备的Zn/Al复合氧化物用于催化酯交换反应生产生物柴油。利用X射线衍射(XRD),原子吸收光谱(AAS),红外光谱(IR),热失重(TG)和低温N_2吸附法(BET)等技术对前驱体及催化剂进行表征。结果表明,Zn和Al物质的量比为3.74时所制得前驱体形成单一类水滑石结构,煅烧所得Zn/Al复合氧化物中Al完全以无定形存在,ZnO分散度好,碱强度最高。将该催化剂在200℃,2.5 MPa,醇油比42:1,催化剂质量分数1.4%的条件下催化菜籽油-甲醇酯交换反应时,菜籽油转化率达到84.53%。Zn/Al hydrotalcite-like compounds with different Zn/Al ratios were prepared by co-precipitation of Zn （NO3）2 and Al （NO3）3 solutions, from which a serials of Zn/Al complex oxide catalysts were obtained by calcining the hydrotalcite-like precursors. The catalysts obtained were used in the transesterification reaction of rapeseed oil and methanol. Both precursor and catalyst were characterized with with X-ray diffractomer （XRD）, atomic absorption spectrometry （AAS）, FT-IR spectrornete （FT-IR）, thermogravimetry analysis （TG） and Brunauer-Enmet-Teller （BET） methods. The results showed that a complete hydrotalcite-like structure was obtained using precursor with 3. 74 ratio of Zn to Al, and thereafter the derived oxide catalyst possessed the highest basicity and exhibited the highest catalytic activity. The characterization results suggested that the alumina oxide was highly dispersed or existed in amorphous form. Under the conditions of 200℃, 2.5 MPa, 42 ： 1 molar ratio of methanol to rapeseed oil and catalyst mass fraction 1.4%, the conversion of rapeseed oil was 84.53 %.

关 键 词：生物柴油 锌/铝复合氧化物 酯交换反应 催化活性 

分 类 号：TE667[石油与天然气工程—油气加工工程]