SnCl_4/C催化高酸值皂脚制备乙酯生物柴油

Preparation of Ethyl Biodiesel from High Acid Value Soapstock by SnCl_4/C

利用活性炭负载SnCl4（SnCl4/C）固体酸催化剂,考察了油酸乙酯合成过程中催化剂的制备、反复使用效能以及最佳催化时间,并选取油酸和月桂酸作为碱炼皂脚中C18和C12脂肪酸代表物合成乙酯生物柴油,比较了油酸乙酯和月桂酸乙酯的生物柴油品质。结果表明：SnCl4/C催化剂在负载率45%时,重复使用5次时酯化率保持在71%-73%范围内,具有较好的稳定性;在反应温度89℃、醇油物质的量比6∶1条件下,合成油酸乙酯最佳反应时间为8 h,分别以C12和C18脂肪酸为原料制备的乙酯生物柴油均基本符合国家标准,其中以C12脂肪酸制备的乙酯生物柴油品质略好于C18脂肪酸;乙酯生物柴油在一定程度上可以替代甲酯生物柴油。

For producing ethyl biodiesel by the transesterification reaction of fatty acid with ethanol,the preparation and re-use feasibility of the catalyst,and the effect of reaction time were individually investigated using SnCl4/C as catalyst at 89℃ and molar ratio of ethanol to oil 6∶1.Subsequently,the characteristics of two types of biodiesels,i.e.,ethyl laurate and ethyl oleate,prepared from oleic acid（C18） and lauric acid（C12） were compared.Results：SnCl4/C can be steadily reproduced and has stable and high catalytic activity.The cost-effective reaction time for the transesterification reaction is 8 h.The two types of ethyl biodiesel originated from oleic acid（C18） and lauric acid（C12） have comparable biodiesel characteristics which can satisfy the requirements of Chinese Biodiesel Standard and can replace methyl biodiesel to some extent.