Bartling K, Thompson J U, Pfromm P H, Czermak P, Rezac M E
Institute of Paper Science and Technology, 500 10th Street NW, Atlanta, Georgia 30318, USA.
Biotechnol Bioeng. 2001 Dec 20;75(6):676-81. doi: 10.1002/bit.1193.
The esterification of geraniol with acetic acid in n-hexane was investigated. A commercial lipase preparation from Candida antarctica was used as catalyst. The equilibrium conversion (no water removal) was found to be 94% for the reaction of 0.1 M alcohol and 0.1 M acid in n-hexane at 30 degrees C. This was shown by both hydrolysis and esterification reactions. The activation energy of reaction over the temperature range 10 degrees to 50 degrees C was found to be 16 kJ/mol. The standard heat of reaction was -28 kJ/mol. Membrane pervaporation using a cellulose acetate/ceramic composite membrane was then employed for selective removal of water from the reaction mixture. The membrane was highly effective at removing water while retaining all reaction components. Negligible transport of the solvent n-hexane was observed. Water removal by pervaporation increased the reaction rate by approximately 150% and increased steady-state conversion to 100%.
研究了香叶醇与乙酸在正己烷中的酯化反应。使用了一种来自南极假丝酵母的商业脂肪酶制剂作为催化剂。在30℃下，0.1M醇和0.1M酸在正己烷中的反应（不除水）的平衡转化率为94%。水解和酯化反应均表明了这一点。在10℃至50℃温度范围内反应的活化能为16kJ/mol。反应的标准热为-28kJ/mol。然后采用醋酸纤维素/陶瓷复合膜进行膜渗透蒸发，以从反应混合物中选择性除去水。该膜在除去水的同时能有效保留所有反应组分，对溶剂正己烷的传输可忽略不计。通过渗透蒸发除水使反应速率提高了约150%，并使稳态转化率提高到100%。
