Synthesis Of Biodiesel From Jatropha Curcas Seed Oil Catalyzed By Mesoporous Solid Base

Energy is inseparable from human life,but fossil energy is non-renewable and causes serious environmental pollution.Therefore,it is necessary to find new clean and renewable energy.Biodiesel has become a research hotspot in recent years due to its excellent physical and chemical properties.Solid base catalyst has excellent performance in biodiesel catalysis.In this paper,two solid base catalysts were synthesized by co-precipitation method and used in the preparation of biodiesel.（1）Jatropha curcas seed oil was used as the feedstock oil for biodiesel preparation.Acid value and low moisture and volatile content.The negative effect on transesterification reaction was basically negligible,so it was an ideal feedstock oil for biodiesel preparation.（2）Using attapulgite as raw material,cetyltrimethylammonium bromide（CTAB）was added under alkaline conditions,and then the MCM-41 mesoporous silica molecular sieve was prepared by hydrothermal crystallization in a reaction kettle,and then KF/Mg-Al-LDO/MCM-41 was prepared by co-precipitation method and constant volume impregnation method.The preparation conditions of the catalyst were optimized by single factor method and response surface method.Optimization conditions:concentration of CTAB solution was 11.1%,mass ratio of Mg-Al hydrotalcite to MCM-41 was 2.1:1,KF load was 21.7wt%,calcination temperature was 595.2℃,calcination time was 5.3 h,and the yield was 95.47%.（3）K₂CO₃/MMT/Fe₃O₄ was prepared by introducing magnetic core into Na-montmorillonite as carrier and introducing K₂CO3 through equal-volume impregnation method.The preparation conditions of the catalyst were optimized by single factor method and response surface method.Optimization conditions:24.8 mmol/100g CTAB usage amount,25.3wt%K₂CO₃ loading amount,367.2℃calcination temperature,2.5 h calcination time,and 94.76%yield.The magnetic K₂CO₃/MMT/Fe₃O₄ catalyst was characterized by XRD,FT-IR and SEM,and the alkali strength and alkali distribution were measured.The results showed that the magnetic catalyst was easy to separate in the reaction system.（4）KF/Mg-Al-LDO/MCM-41 and K₂CO₃/MMT/Fe₃O₄ catalysts were combined with single factor method and response surface method to optimize the preparation conditions of biodiesel.The preparation conditions of KF/Mg-Al-LDO/MCM-41 catalyzed transesterification reaction are as follows:catalyst dosage is 4.1 wt%,molar ratio of alcohol to oil is 9.9:1,reaction temperature is65.7℃,reaction time is 3.1 h,and the yield is 96.22%.The reaction conditions of K₂CO₃/MMT/Fe₃O₄ catalyzed transesterification were as follows:catalyst dosage5.1 wt%,molar ratio of alcohol to oil 10.2:1,reaction temperature 65.2℃,reaction time 3.4 h,and yield of 95.41%.