介孔碳基固体酸的制备及在生物柴油生产中的应用

以蔗糖为碳源、SiO_2为模板剂,采用碳化-磺化法制备介孔碳基固体酸催化剂,通过酸碱滴定、BET、XRD、FT-IR、SEM等方法对其进行表征,考察碳化温度、磺化温度对催化剂性能的影响,并将其用于大豆油与甲醇的酯交换反应,考察反应条件及原料中脂肪酸含量的影响。结果表明:制备催化剂的适宜条件为碳化温度400℃、磺化温度170℃;大豆油与甲醇酯交换反应的最佳条件为反应温度130℃、醇油摩尔比30、反应时间4h、催化剂用量(占大豆油质量的百分比)8%,生物柴油收率最高达95.94%;连续使用5次后,生物柴油收率仍达到85.46%,说明催化剂具有良好的稳定性;原料中的脂肪酸对催化剂性能有一定的负面影响,但当脂肪酸质量分数达到15%时,生物柴油收率依然可达90%以上。

PREPARATION OF MESOPOROUS CARBON-BASED SOLID ACID AND ITS APPLICATION IN BIODIESEL PRODUCTION

Mesoporous carbon-based solid acid catalysts were prepared by carbonization-sulfonation method with SiO2 as a template and sucrose as carbon source. The catalysts were characterized by acidimetric analysis, BET, XRD, FT-IR and SEM. The effects of carbonization temperature and sulfonation temperature on the catalyst performance were investigated, then the prepared catalysts were used in transesterification reaction between soybean oil and methanol, and the effects of reaction conditions and the content of fatty acids in the feed were studied. The results show that the optimum preparation conditions of the catalysts for carbonation and sulfonation temperature were 400 ℃ and 170 ℃, respectively; the yield of biodiesel for transesterification reaction between soybean oil and methanol reached 95.94% under the optimum conditions of molar ratio of methanol to soybean oil 30, reaction time 4 h and catalyst dosage of 8% (accounted for the percentage of soybean oil ); The yield of biodiesel is still over 85.46% after the catalyst was reused for five times, ,indicating the good stability of the catalyst. The fatty acids in the feedstock have a negative effect on the performance of the catalyst. However, in the case of 15% fatty acid in the raw material, the biodiesel yield is still over 90%.