KOH/Al_2O_3固体碱催化酯交换合成生物柴油的研究

Preparation of Biodiesel by Transesterification over KOH/Al_2O_3 Catalyst

采用等体积浸渍法制备了KOH/Al_2O_3负载型固体碱催化剂,并将其用于菜籽油与甲醇酯交换法合成生物柴油的研究;分别考察了催化剂附载量、煅烧温度、醇油摩尔比、反应温度、反应时间等条件对生物柴油产率的影响;结果表明:用等体积浸渍法,在400℃煅烧5 h,制得负载量为20%(w)的KOH/Al_2O_3催化剂.当催化剂用量为5%(w),醇油摩尔比为12:1,在60℃下反应2 h后,生物柴油产率高达92.3%(w).运用X-射线衍射、比表面积测定等手段对催化剂结构进行了表征,结果表明催化剂的活性与其晶相和比表面积密切相关.

Synthesis of biodiesel by transesterification of rapeseed oil and methanol catalyzed by KOH/Al_2O_3 solid base was studied.The catalyst was prepared by isochoric impregnation.Effects of some factors on the transesterification were investigated systematically and reaction conditions were optimized.The optimum reaction conditions on KOH/Al_2O_3catalyst were:mass ratio of KOH to Al_2O_320%;calcination temperature 400℃for 5 h; molar ratio of methanol to oil 12:1,the amount of catalyst 5 wt%;reaction temperature...