松木模板法制备CaAl2xO3x+1固体碱催化剂

Preparation of CaAl2xO3x+1solid base catalyst by pinewood template method

关键词:  模板法  松木屑  固体碱  催化剂  蓖麻油  生物柴油 

Key words:  template method  pinewood sawdust  solid base  catalyst  castor oil  biodiesel

摘要:

目的 采用松木模板法制备固体碱催化剂旨在改变催化剂结构、提高催化剂性能。方法 以一水乙酸钙、二水碱式乙酸铝为原料、松木屑为模板,经浸渍、干燥、焙烧制备CaAl2xO3x+1固体碱催化剂。采用单因素试验考查钙铝物质的量比、焙烧温度及焙烧时间对催化剂活性的影响。对催化剂及前驱体进行TG、XRD及SEM表征。结果 制备CaAl2xO3x+1固体碱催化剂的最佳条件:钙铝物质的量比4∶1、焙烧温度900 ℃、焙烧时间7 h。催化剂前驱体温度超过900 ℃后分解基本结束。CaAl2xO3x+1固体碱催化剂晶相结构类似松木屑模板,是由大量无定型物质(Al₂O₃、CaO或其复合物)和少量晶体(CaO)构成的表面光滑的亚微米级颗粒组成。结论 通过松木模板法可制得类似松木结构且活性较高的固体碱催化剂。 

Abstract:

Objective The purpose of preparing solid base catalyst by pinewood template method is to change the structure of the catalyst and improve the performance of the catalyst. Methods CaAl2xO3x+1 solid base catalyst was prepared by impregnating, drying and roasting using calcium acetate monohydrate, aluminum acetate dihydrate as raw materials and pinewood sawdust as template. The effects of Ca/Al molar ratio, calcination temperature and calcination time on the catalyst activity were investigated by single factor test.The catalysts and precursors were characterized by TG, XRD and SEM. Results The optimum conditions for preparing CaAl2xO3x+1 solid base catalyst were as follows:molar ratio of Ca/Al 4∶1, calcination temperature 900℃, calcination time 7 h. When the temperature of catalyst precursor exceeds 900 ℃, the decomposition basically ends. The crystal phase structure of CaAl2xO3x+1 solid base catalyst is similar to that of pinewood sawdust template. It consists of a submicron particle with smooth surface composed of a large amount of amorphous substances (Al₂O₃, CaO or their compounds) and a small amount of crystals (CaO). Conclusion The solid base catalyst with structure similar pinewood and high activity can be prepared by pinewood template method.