Preparation Of Paramagnetic Core-shell Nanocatalyst And Its Application To Transesterification Of Microalgae Oil

The increasing depletion of oil resources and the improvement of people’s awareness ofenvironmental protection, to speed up the pace of the development of environmentallyfriendly renewable energy. Biodiesel and petroleum diesel is similar to the carbon content(carbon chain length between C14-C24), the main indicators of consistent and can be mixedwith petroleum diesel in any proportion, so it can be widely used. Biodiesel is a long-chainalkyl (methyl, ethyl or propyl) ester prepared from vegetable oils or animal fats. It usuallyrefers to fatty acid ester prepared by the reaction of lipids (such as vegetable oils, animal fats)with alcohols. To the principle of not competing land with food, not competing food withpeople, this subject selected short growth cycle, high oil content, high value-added microalgaeoil as raw material.Pepole traditionally use homogeneous catalyst to catalyze trans-esterification reaction, but there are problems: corrosive to the equipment, can not be recycledto be reused, produce large amounts of waste water after being processed, pollution of theenvironment et al. This study selected the paramagnetic core-shell nanocatalyst, it canmaintain a high catalytic performance, at the same time can be easily separated and reused.The key lies in the preparation of core-shell structure of nanoscale catalyst: the monodispersemagnetic core.First of all, chose the method of co-precipitation to prepared magnetic core, respectivelyusing hydrochloric acid, sodium acetate to modificate the magnetic nanoparticles This methodis simple and large output, but the the magnetic nanoparticles are serious reunion. At the sametime chose solvothermal method to produce magnetic nanoparticles, iron chloride as the ironsource, ethylene glycol as solvent, while using the microwave heating alternative to thetraditional reactor, thereby greatly reducing the reaction time, playing an energy-saving effect,The size of crystal grain is about10nm, magnetic nanoparticles size is about30-50nm, having good monodisperse.Secondly, Using solid base catalyst CaO, NaOH·ZrO2to catalize microalgae oil, CaOand NaOH·ZrO2, the two catalytic methyl content are78.7%and80.4%， peanut oil as theraw material the two catalytic methyl content are100%、95.5%. Known NaOH·ZrO2catalysthas high catalytic activity, when the crude oil as a raw material, repeated use the catalyst, thecatalytic activity is gradually decreased. Also discussed SO2-4/ZrO2microalgae oil as the rawmaterial for catalytic activity, as the temperature rises, the product ester content graduallyincreases, but the increase is not apparently.Finally, For the catalyst is difficult to separated from the reaction system, chose Fe3O4particles as the carrier, the catalytic active material composition coated on the particle surface.Prepared Fe2-3O4@SO4·ZrO2catalysts to catalize microalgae oil t. Impregnated NaOHprepared Fe3O4@NaOH·ZrO2catalysts microalgae oil, reused five times, the results knownby the gradual decrease in catalytic activity, but not much. Microalgae oil acid value is higher,so this project was prepared using a two-step to produce biodiesel. Using core-shellnano-solid acid catalyst Fe2-3O4@SO4·ZrO2pretreatment microalgae crude oil, after usingFe3O4@NaOH·ZrO2catalytic converters esterification, the measured content of the final82.3%of the methyl ester.