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| 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 |
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| DOI： |
| 中文关键词: CaO 复合氧化物 固体碱 催化剂 生物柴油 |
| 英文关键词:calcium oxide complex oxide solid base catalyst biodiesel |
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| 中文摘要: |
| 采用共沉淀、浸渍及高温焙烧的方法制备了CaO/(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CaO/(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；CaO/(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CaO/(Mg-Fe-O)固体碱催化剂介孔中的CaO起主要催化作用；CaO/(Mg-Fe-O)固体碱中的CaO以无定形或微晶的形式高度分散于MgFe2O4及MgO表面。 |
| 英文摘要: |
| 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 transesterification 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 transesterification 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 CO2-3 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 main catalytic role; CaO in the solid base was highly dispersed on the surface of MgFe2O4 and MgO in the form of amorphous or microcrystal. |
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