微水相超声波协同纳米Ca-Mg-Al固体碱催化制备生物柴油  

Preparation of Biodiesel on Nano Ca-Mg-Al Solid Base Catalyst Under Ultrasonic Radiation in Microaqueous Media

作　　者：邓欣[1] 方真[1] 胡远飞[1] 曾虹燕[2] 廖凯波[2] 于长流[3] 

机构地区：[1]中国科学院西双版纳热带植物园昆明分部生物能源组,云南昆明650223 [2]湘潭大学化工学院,湖南湘潭411105 [3]大港油田集团石油化工公司煅烧焦厂,天津300280

出　　处：《石油化工》2009年第10期1071-1075,共5页Petrochemical Technology

基　　金：国家高技术研究发展计划资助项目(2003AA214061)

摘　　要：以尿素为沉淀剂制备了纳米Ca-Mg-Al水滑石,采用X射线衍射、傅里叶变换红外光谱和扫描电子显微镜对其进行了表征,以其煅烧后得到的纳米Ca-Mg-Al复合金属氧化物为固体碱催化剂,采用微水相超声波辐射协同固体碱催化小桐子油与甲醇进行酯交换反应制备了生物柴油,并研究了催化剂的失活原因。实验结果表明,纳米Ca-Mg-Al水滑石的柱撑阴离子为CO_3^(2-),晶粒大小均匀,呈良好的层状结构。在超声波功率210W、占空比0.7、反应时间30min、温度60℃、甲醇与小桐子油摩尔比4∶1、催化剂用量1.5%(基于小桐子油的质量)的反应条件下,生物柴油收率达94.3%,精制后的生物柴油完全符合德国生物柴油标准DIN V 51606:1997。催化剂失活的主要原因是层状结构的塌陷和副产物甘油附着在催化剂表面,使用后的催化剂用乙醇洗去表面的甘油后,可连续使用12次。Nano Ca-Mg-Al hydrotalcite was prepared by coprecipitation using urea as precipitation agent,and characterized by means of XRD, FTIR and SEM. With the aid of ultrasonic radiation, biodiesel were prepared from Jatropha oil and methanol in microaqueous media with calcined nano Ca-Mg-Al hydrotalcite as solid base catalyst. The results showed that Ca-Mg-Al hydrotalcite existed in laminar structure, particle size distributed uniformly, and the interlayer pillared anion was carbonate. Under conditions：ultrasonic power 210 W, duty ratio 0.7, reaction time 30 min, temperature 60 ℃, mole ratio of methanol to Jatropha oil 4 ： 1 and catalyst mass fraction of 1.5% （based on Jatropha oil）, yield of biodiesel was 94.3%. The specifications of biodiesel after purification completely met DIN V 51606：1997. The main causes of catalyst de-activation were surface absorption of by-product glycerol, aggregation of catalyst particles and partial collapse of laminar structure. After removing the glycerol from surface of catalyst by washing with ethanol, the catalyst could be reused for 12 times.

关 键 词：固体碱催化剂 生物柴油 小桐子油 超声波 微水相 酯交换 

分 类 号：TQ645.1[化学工程—精细化工]