CaO/(Mg-Fe-O)固体碱的制备及其酯交换催化活性研究  

Preparation of CaO/( Mg-Fe-O) solid base and its catalytic activity in transesterification

作　　者：李晓红[1] 靳福全[1] 

机构地区：[1]太原工业学院化学与化工系,太原030008

出　　处：《中国油脂》2015年第7期55-59,共5页China Oils and Fats

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)

摘　　要：采用共沉淀、浸渍及高温焙烧的方法制备了Ca O/(Mg-Fe-O)固体碱催化剂,以蓖麻油转化率为催化剂活性评价指标,采用正交实验考察了制备条件对催化剂酯交换催化活性的影响。得到的优化条件为:Mg/Fe摩尔比3∶1,Ca(Ac)2浸渍液质量分数15%,浸渍时间12 h,焙烧温度800℃,焙烧时间2 h。以优化条件下制备的Ca O/(Mg-Fe-O)固体碱为催化剂,用于蓖麻油和甲醇酯交换反应,蓖麻油转化率可达94.74%。采用TG-DTA、FTIR、BET及XRD技术对催化剂及其前驱体进行了表征。结果表明:当温度超过750℃时,Ca(Ac)2/(Mg-Fe水滑石)几乎不再失重;Ca O/(Mg-Fe-O)固体碱和Ca(Ac)2/(Mg-Fe水滑石)相比,其—OH和CO2-3的红外吸收峰显著下降;负载于Ca O/(Mg-Fe-O)固体碱催化剂介孔中的Ca O起主要催化作用;Ca O/(Mg-Fe-O)固体碱中的Ca O以无定形或微晶的形式高度分散于Mg Fe2O4及Mg O表面。CaO/（Mg-Fe-O） solid base catalyst was prepared by coprecipitation,impregnation and calcination. Taking conversion rate of castor seed oil as evaluation index of catalyst activity, the effects of preparation conditions on the catalytic activity of CaO/（Mg - Fe - O） solid base in transesteritlcation were investigated through orthogonal experiment. The optimal conditions were obtained as follows： molar ratio of Mg to Fe 3：1, mass fraction of calcium acetate impregnation solution 15%, impregnation time 12 h, calcination temperature 800 ℃, calcination time 2 h. CaO/（Mg - Fe - O） solid base prepared under the optimal conditions was used as catalyst in the tram- estefification of castor seed oil and methanol, and the conversion rate of castor seed oil reached 94. 74%. The catalyst and its precursor were characterized by TG - DTA,FTIR,BET and XRD. The results revealed that when the temperature exceeded 750℃, Ca （Ac）2/（Mg- Fe hydrotalcite） almost did not loss weight; compared with Ca（Ac）2/（Mg-Fe hydrotalcite）, --OH and CO32- infrared absorption peaks of CaO/（Mg-Fe-O） solid base decreased significantly; CaO supported in mesoporous of the solid base catalyst CaO /（Mg- Fe- O） played the nmin catalytic role; CaO in the solid base was highly dispersed on the surface of MgFe20＋and MgO in the form of amorphous or microcrystal.

关 键 词：CAO 复合氧化物 固体碱 催化剂 生物柴油 

分 类 号：TE667[石油与天然气工程—油气加工工程] O643.36[理学—物理化学]