Study Of Biodiesel Production Catalyzed By Nano Solid Base

In this study,namo KF/γ-Al₂O₃ were prepared by impregnation method and blending method and their activity for biodiesel production in the continuous double transesterification was investigated and discovered that nano KF/γ-Al₂O₃ obtained by blending method exhibits better catalytic performance.The experimental result showed that the yield of fatty acid methyl ester（FAME）could reached 98.82% at the oil/DMC/methanol ratio of 1/1/8,the amount of catalyst 15% under 65℃ in 30 min.Compared with the nano KF/γ-Al₂O₃ made by impregnation method,the yield of FAME was increased by 40% under the same reaction condition.And compared with tranditional reaction system,the raction time was shorten by 40 min.The physicochemical properties of catalyst was evidenced by TGA,BET,CO₂-TPD and IR.The results indicated that the high activity of catalyst is mainly due to the generation of new phase K2 O with strong alkaline on the surface of γ-Al₂O₃ during calcination,In the paper,a series of nanometer-sized alkali metal oxide solid base was prepared by sol-gel method and their catalytic performance for biodiesel prepared in a continuous double transesterification system were investigated.The experimental result showed that catalytic performance of nano catalysts was much better than general solid alkali,especially,nano CaO showed good catalytic activity.The yield of FAME exceeded 92.82% at the oil/DMC/methanol ratio of 1/1/8,the amount of catalyst 5% under 65℃ in 4h.Compared with common CaO,the yield of FAME was increased by 25% under the same reaction condition.The physicochemical properties of catalyst was evidenced by TGA,BET,CO₂-TPD and IR.The results indicated that the calcining temperature has a signification effect on the particle size and the crystallinity of powders.Moreover,the specific surface area,pore size and pore volumn of catalysts was increased remarkablely.The all consequence manifested that surface structure is important factor that affect the performance of catalysts.A series of nano mixed solid bases were prepared by homogeneous precipitation method and reaction conditions for biodiesel production in the continuous double transesterification were investigated.The experimental results showed that nano MgO-CaO exhibits an excellent catalytic performance.Under the optimum condition,the biodiesel yield could reached 97.39% at the oil/DMC/methanol ratio of 1/1/6,the amount of catalyst 10% under 65℃ in 4h.The catalysts were characterized and discovered that calcining temperature has no remarkable effect on crystal shape of MgO-CaO powders.However,the calcining temperature has a signification effect on the surface structure and catalytic activity of catalysts.When the calcining temperature is 800℃,the largest surface,pore size and pore volumn nano MgO-CaO powders is produced.Moreover,MgO and CaO powders have uniform dispersion.In the article,the catalytic performance of namo CaO obtained by calcining nano Ca（OH）₂ made by reversed precipitation method for biodiesel production in continuous double transesterification was investigated.The experimental results show that nano CaO by calcining Ca（OH）₂ presoma exhibits an excellent catalytic performance.Under the optimum condition（reaction temperature 65℃,oil/dimethyl carbonate/ methanol molar ratio 1:1:8,calcination temperature 600℃）the yield of biodiesel could reached 94.24% after 1h at catalyst amount of 10%.Compared with common Ca O,the yield of FAME was increased by 40% and compared with nano CaO made by sol-gel,the reaction yield is shortened 3h.The catalysts were characterized and discovered that calcining temperature has a signification effect on the nano CaO obtained by sol-gel method,while calcining temperature has weak influence on the surface structure of these catalysts and has a signification effect on the surface basicit.