负载型固体碱催化蒜头果油甲酯化的研究

The Methyl Esterification of Malania oleifera oil Catalyzed by Supported Solid Base

通过氨水沉淀、Na_2CO_3浸渍、焙烧等处理步骤制备了负载型固体碱Na_2O/Al_2O_3-MgO催化剂,将Na_2O/Al_2O_3-MgO催化剂应用于蒜头果油甲酯化过程中,分析各工艺条件对蒜头果油甲酯化转化率的影响。结果表明:借助XRD、BET、SEM分析发现,催化剂前驱体具有类水滑石结构,该前驱体经焙烧处理后,所得催化剂比表面积为29.5 m^2/g,其成分除Al_2O_3、MgO外,还存在Na-Al及Na-Al-Mg氧化物;通过单因素及正交试验在综合考虑降低实际生产成本的基础上获得了优化的工艺条件,即在保持甲醇回流的状态下,催化剂用量为2%、反应时间5 h、醇油物质的量比为15∶1,此条件下,蒜头果油甲酯化转化率可达到96.4%。

The supported solid base catalyst Na2O/Al2O3-MgO, was prepared through ammonia precipitation process, impregnation process with NaECO3 and calcination process. The effects of various process condition on the methyl esterification yield of Malania oleifera oil were analyzed by applying Na2O/Al2O3-MgO catalyst. The findings indicated that by the analyses of XRD, SEM and BET, it could be seen that catalyst precursor had the structure of hydrotaleite-like compounds and the specific surface area of roasted catalyst was 29.5 m2/g. In addition to Al2O3 and MgO, Na-Al and Na-AI-Mg oxides were identified in the catalyst by XRD. By single factor test and orthogonal test, considering higher conversion rate and lower production cost, the optimal process condition for applying the Na2O/Al2O3-MgO catalyst in methyl esterification of M. oleifera oil was obtained. In the condition of keeping the re- flux of methanol, the catalyst amount as 2% and the molar ratio of methanol to oil as 15 ： 1, after a reaction time of 5 h, the conversion rate of methyl esterification of M. oleifera oil could achieve 96.4%.