Preparation Of Compound Magnetic LDHs And Its Application In Biodiesel Transesterification

With the development of the world,further depletion of fossil fuel reserves,energy crisis and global warming,environmental pollution and other issues forced the humans to find renewable energy sources.The survival of humanity is inseparable from nature,due to overexploitation of resources,resulting in increasingly serious environmental problems,environmental protection is imminent.Biodiesel technology comes from nature-renewable plant,animal oil extracted from oil,through a chemical reaction produced can replace fossil fuels and renewable energy.Biodiesel is environmentally friendly and safe storage and transportation,renewable,superior dynamic performance and many other advantages,is considered an ideal alternative to fossil fuels.Currently bio-oil production stage mainly rely on a solid acid catalyst with a solid base oil transesterification,the catalyst under milder conditions can exhibit high activity catalyst and product separation difficulties still exist,enables consumption increases,detrimental to their long-term development.Magnetic Fe₃O₄ were synthesized by FeCl3·6H₂O and FeCl2·4H₂O,and used as a raw material for preparing Fe₃O₄/ MgAl-LDH.The calcined production Fe₃O₄ / Mg?Al?O and the biodiesel yield were taken as the catalyst in the synthesis of biodiesel from microalgae oil with methanol and the activity catalyst index,respectively.Several measurments such as TGDTG?XRD?SEM?EDS?TEM?N2 absorption-desorption and VSM were employed for characterising the catalysts.The results showed that: MgAl-LDH?Mg?Al?O successfully loaded on Fe₃O₄ and the particles had strong magnetic response.When reaction time was 4h,methanol/oil ratio was 13:1,the biodiesel oil yield could reach to 90%.After using three times the catalyst still had activity and could be easily separated and recycled.By coprecipitation preparation of zinc modified Fe₃O₄/ ZnMgAl-LDHs new type solid alkali catalyst,by thermogravimetric?TG-DTG?and X-ray diffraction?XRD?,scanning electron microscopy?SEM?,energy spectrum?EDS?,transmission electron microscopy?TEM?and vibrating sample magnetometer?VSM?to characterize.The research results show that when the doping amount of Zn2 + 15%,n?methanol?: n?micro algae oil?= 12:1,m?Fe₃O₄ / ZnMg?Al?O?: m?micro algae oil?= 3%,65 ? reaction 3h,Fe₃O₄/ZnMgAl-LDHs the highest catalytic activity,microalgae yield up to 94% of new biological diesel oil,after repeated use 7 times,biodiesel yield is still higher than 82%.