Pd/C上松脂催化歧化反应的研究  

Study on Catalytic Disproportionation of Pine Gum over Pd/C

作　　者：王琳琳[1] 孙文静[1] 陈小鹏[1] 胡雄光[1] 童张法[1] 

机构地区：[1]广西大学化学化工学院,广西南宁530004

出　　处：《高校化学工程学报》2007年第5期784-789,共6页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金资助项目(30560119);广西青年基金资助项目(0640001);广西自然科学基金资助项目(0575003);广西研究生教育创新计划项目(2006105930817D06);广西大学科研基金资助项目(X061020)

摘　　要：以Pd/C为催化剂、马尾松和湿地松松脂为原料并利用其自身所含松节油作溶剂进行催化歧化反应制备歧化松香和对-伞花烃的研究。采用GC-MS和GC法定性定量分析了松脂催化歧化反应产物,并探讨了松脂歧化反应的竞争机制,发现酸性物与中性油的分子间氢转移反应均以脱氢反应为主,主产物为脱氢枞酸和对-伞花烃,伴随少量加氢反应。考察了搅拌速度对外扩散的影响,表明当搅拌转速大于500r?min?1时,即可消除外扩散对反应速度的影响。由均匀实验设计方法确定了Pd/C上马尾松松脂催化歧化反应的最佳工艺条件为:反应温度260℃,催化剂用量为占松脂质量的0.2%,反应时间为180min,该条件下脱氢枞酸含量(占酸性物的重量百分数)和对-伞花烃含量(占中性油的重量百分数)分别为89.45%、61.76%,所得产品优于ZBB72002-1984的特级歧化松香指标。比较了马尾松松脂与湿地松松脂催化歧化反应的效果,在相同反应条件下以马尾松松脂为原料制得的脱氢枞酸比以湿地松松脂为原料制得歧化产品中脱氢枞酸的含量高18%、对-伞花烃含量高16%。Using turpentine from pine gum itself as solvent, catalytic disproportionations of P. massoniana and P. elliottii pine gums for the preparation of disproportionated rosin and p-cymene over Pd/C catalyst were studied. The products of catalytic disproportionation were quantitatively and qualitatively analyzed by GC and GC-MS, and the competition mechanism of the disproportionation reaction was discussed. The results show that, during the intermolecular hydrogen transfer reaction of resin acids and turpentine, dehydrogenation is the main reaction companying with a little hydrogenation reaction, and its main products are p-cymene, dehydroabietic acid and hydrogenation resin acids. The effect of stirring speed on external diffusion was investigated and it was found that the effect of external diffusion on the reaction rate can be eliminated when the stirring speed is over 500 r.min^-1. Based on the uniform design method, the optimal reaction conditions for disproportionation of P. massoniana over Pd/C were obtained experimentally as follows： reaction temperature 260℃, catalyst dosage 0.2% （based on pine gum weight）, reaction time 180 min. Under above conditions, the contents of dehydroabietic acid and p-cymene in the disproportionation product are 89.45% （based on the acid material weight） and 61.76% （based on the neutral oil weight）, respectively. According to the Chinese Standard of B72002-1984 for disproportionated rosin products, the quality indexes of the disproportionation products are higher than those of the standard for superfine disproportionated rosin. The catalytic disproportionation results ofP. massoniana and P. elliottii pine gums were compared, and it shows that the contents of dehydroabietic acidand p-cymene in the products obtained from the disproportionation of P. massoniana pine gum are respectively 18% and 16% higher than that from P. elliottii pine gum.

关 键 词：松脂 催化歧化 歧化松香 对-伞花烃 

分 类 号：TQ351.471[化学工程] TQ032.41