电石渣负载氟化钾的催化酯交换特性研究

通过浸渍法制备以氟化钾为活性体、电石渣为载体的负载型钙基酯交换催化剂,并在借助X射线荧光光谱仪、热分析天平、X射线衍射仪、氮气吸附-脱附仪、扫描电子显微镜以及哈米特指示剂法等手段对催化剂表征,以及气相色谱仪对原料油成分分析的基础上,通过间歇式酯交换实验系统,从催化剂添加量、醇油物质的量比、酯交换温度与时间等影响因素出发,研究了电石渣负载氟化钾催化花生油与甲醇酯交换的特性。电石渣负载氟化钾后,产生KCaF3、CaF2以及KF等新物相,并且在催化剂添加量为5%、反应温度为62℃、反应时间为2 h以及醇油物质的量比为15的酯交换条件下,能够取得91.58%的甘油收率,相比较氢氧化钙和未有活性体负载的电石渣,其催化酯交换性能得到提高。

Catalytic performance of carbide slag loaded with potassium fluoride in transesterification

Using the potassium fluoride as the active site and the carbide slag as the carrier, a calcium-based loaded catalyst for the transesterification was prepared through the impregnation method. The catalyst was characterized by X-ray fluorescence, thermogravimetric analysis, X-ray diffraction, nitrogen adsorption and desorption, scanning electron microscope and Hammett indicator. Also, the composition of peanut oil was analyzed by gas chromatograph. Then, the performance of prepared catalyst in the transesterification of peanut oil with methanol was examined with a batchwise experimental system. After being loaded with potassium fluoride, the new textural phases of KCaF₃, CaF₂ and KF emerge. Under the condition of the catalyst addition of 5%, the transesterification temperature of 62 ℃, the transesterification time of 2 h and the molar ratio of methanol to oil of 15, the glycerol yield of 91.58% can be achieved. Compared with calcium hydroxide and unloaded carbide slag, this loaded catalyst has a better performance.