CaO/Zn-Fe-O固体碱的制备、表征及油脂醇解催化活性  

PREPARATION AND CHARACTERIZATION OF CaO/Zn-Fe-O SOLID BASE AND ITS CATALYTIC ACTIVITY IN OIL ALCOHOLYSIS

作　　者：靳福全[1] 

机构地区：[1]太原工业学院化学与化工系,山西太原030008

出　　处：《精细石油化工》2015年第6期8-13,共6页Speciality Petrochemicals

基　　金：山西省高校科技开发项目(2010130);山西省高等学校大学生创新创业训练项目(2011370);太原工业学院大学生创新创业训练项目(2014年)

摘　　要：采用共沉淀、浸渍及高温焙烧的方法制备了CaO/Zn-Fe-O固体碱催化剂。采用正交试验考察了制备条件对CaO/Zn-Fe-O固体碱油脂醇解催化活性的影响,得到的优化条件为:n(Zn)/n(Fe)=5,Ca(Ac)_2浸渍液质量分数0.15、浸渍时间12h、焙烧温度800℃、焙烧时间3h。以优化条件下制备的CaO/Zn-Fe-O固体碱为催化剂,在n(醇)/n(油)=9、m(催化剂)/m(油)=0.04、搅拌速率400r/min、反应温度70℃、反应时间3h的条件下,蓖麻油转化率为84.21%。采用TG-DTA、FT-IR、BET及XRD技术对催化剂及其前驱体进行了表征。结果表明:Ca(Ac)_2/Zn-Fe水滑石TG曲线出现3个失重台阶,分别位于180~250℃、250~380℃及700~750℃温区;CaO/Zn-Fe-O固体碱催化剂BET比表面积为6.19m^2/g,BJH脱附累积孔容为0.011 6cm^3/g,BJH脱附平均孔半径为3.84nm;CaO/Zn-Fe-O固体碱中的活性组分CaO以无定形或微晶的形式高度分散于Zn-Fe-O复合氧化物载体表面。CaO/Zn-Fe-O solid base catalyst was prepared by coprecipitation, impregnation and calcination method. Effects of preparation conditions on the catalytic activity of CaO/Zn-Fe-O solid base in oil alcoholysis were investigated via orthogonal tests. Optimized conditions were obtained as Zn/Fe molar ratio of 5, Ca（Ac）2 impregnating solution mass fraction of 0.15, impregnating time of 12 h, calcination temperature of 800 ℃ and calcination time of 3 h. Castor oil conversion could reach 84.9.1% in the presence of the CaO/Zn-Fe-O catalyst prepared under optimized conditions when the reaction was carried out at 70 ℃ for 3 h with alcohol/oil molar ratio of 9, catalyst/oil mass ratio of 0.04 and stirring speed of 400 r/min. The catalyst and its precursor were characterized with techniques of TG-DTA, BET, FT-IR and XRD. The results showed that Ca（Ac）2/Zn-Fe hydrotalcite had three weight loss steps in the TG curve, appearing respectively in 180 -250 ℃, 250 -380 ℃ and 700 - 750 ℃. BET surface area of CaO/Zn-Fe-O solid base catalyst was 6.19 m2/g, BJH desorption cumulative volume of pores was 0. 011 6 cm3/g and BJH desorption average pore radius was 3.84 nm. The active ingredient CaO in the solid base was highly dispersed on the Zn-Fe-O complex oxide support surface in an amorphous or microcrystalline way.

关 键 词：氧化钙 复合氧化物 固体碱 制备 催化 催化剂 生物柴油 

分 类 号：TQ426[化学工程]