Abstract:

To improve the content of monoglycerides （MAGs） in the product, the preparation of MAGs by glycerolysis of triglyceride catalyzed by Ce modified MgO catalysts was studied. MgO support was prepared by hydrothermal method with magnesium oxide as raw material, and Ce modified MgO catalyst was prepared by constant-volume impregnation method with cerium nitrate and MgO support as raw materials. The orthogonal test was designed, in which reaction time, reaction temperature and catalyst dosage were optimized. The effect of Ce addition on the content of MAGs in crude products was also investigated. The structure of Ce modified MgO catalysts was analyzed by BET, XRD and CO₂-TPD. The experimental results show that the reaction temperature has the highest significance level among the three selected factors affecting the content of MAGs. When the amount of Ce is 0.3%, catalyst dosage is 0.5% （of the total mass of glycerol and glyceryl tristearate）, the molar ratio of glycerol to glyceryl tristearate is 2∶1, the reaction temperature is 220 ℃, and the reaction time is 2 h, the content of MAGs is 42.0%. The characterization results show that, the addition of Ce has little effect on the specific surface area, pore volume and pore size of the catalyst when the Ce content is less than 0.3%, but the catalyst will be more alkaline. When the Ce content is more than 0.5%, the specific surface area, pore volume, pore size and alkalinity of the catalyst are significantly decreased.

Key words: monoglycerides, preparation, glyceryl tristearate, Ce modified MgO catalyst