镁铝水滑石催化制备生物柴油的研究

Study on the preparation of biodiesel catalyzed over hydrotalcite

采用共沉淀法制备镁铝水滑石,并用浸渍法制得KF负载量不同的KF/镁铝水滑石固体碱催化剂,以大豆油和甲醇进行的酯交换反应为研究对象考察催化剂的制备条件,实验结果表明,当镁铝比为3∶1时,KF的负载量为50%(KF占镁铝水滑石的质量)在500℃下煅烧3 h时催化剂具有较高的催化活性。采用Hammett指示剂法测定该KF/镁铝水滑石表面碱量为8.45 mmol/g。

Mg-Al hydrotalcite(HT)was prepared by co-precipitation method..The KF/hydrotalcite solid base catalysts were prepared using the hydrotalcite as a carrier by impregnation. The preparation conditions of catalyst were investigated. The result shows that the molar ratio of Mg to Al is 3∶1,the load ratio of KF/hydrotalcite(KF accounted hydrotalcite mass ratio)50%,calcination temperature 500℃,calcination time 3h. The catalysts show best catalytic activity in the transesterification of soybean oil with methanol. The base amount(8.45 mmol/g)on catalyst surface was determined by mean of Hammett indication method.