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.