作　　者： ; ; ; ; ; ;

机构地区： 华南理工大学轻工与食品学院轻化工研究所

出　　处： 《中南大学学报（自然科学版）》 2010年第3期883-889,共7页

摘　　要： 在超声波条件下,对纳米KF/γ-Al2O3催化大豆油与甲醇酯交换反应中影响甲酯含量的诸因素进行考察,并采用XRD、TEM、BET比表面积分析以及Hammett指示剂法等手段对使用前后纳米KF/γ-Al2O3催化剂进行表征。研究结果表明:超声功率密度对酯交换反应有明显的影响;在最优条件下:超声功率密度为53.3W/L,醇油物质的量比为6:1,催化剂用量为3%,在45℃时反应35min,酯交换反应甲酯含量最高达98.70%;与机械搅拌相比,酯交换反应时间由2h缩短为35min,催化剂和甲醇用量减少,反应条件更温和;超声作用对催化剂KF/γ-Al2O3的表面负载和结构没有显著影响,但催化剂比表面积下降明显,由60.34m2/g下降到37.26m2/g。 The nano-structured KF/γ-Al2O3–catalyzed synthesis of biodiesel was performed in ultrasonic irradiation. Effects of experimental parameters including ultrasonic power density,molar ratio of methanol to soybean oil,catalyst amount,reaction temperature and time on the transesterification of soybean oil and methanol were investigated. The fresh and used catalysts were characterized by means of XRD,TEM and BET. The results indicate that increasing the ultrasonic power density causes the increase in the methyl esters concentration of the transesterification. The maximum concentration of methyl esters is 98.70% under the following optimized conditions：ultrasonic power density 53.3 W/L; molar ratio of methanol to soybean oil 6：1; mass ratio of catalyst to soybean oil 3%; reaction temperature 45 ℃ and reaction time 35 min. In comparison to the mechanical stirring,the ultrasonic irradiation allows the significant reduction of the amounts of KF/γ-Al2O3 and methanol and the time requires for reaching equilibrium. The structure of nano KF/γ-Al2O3 surface does not change,but the specific surface area of the nano-catalyst greatly reduces from 60.34 m2/g to 37.26 m2/g after transesterification of soybean oil and methanol in the ultrasound field.

关 键 词： 超声 氟化钾 氧化铝 酯交换 生物柴油 大豆油

领　　域： [化学工程]