丁酸发酵液萃取-酯化偶联合成丁酸乙酯的研究

Study on Synthesis of Ethyl Butyrate by Butyric Acid Fermentation Broth Extraction Coupling with Esterification

丁酸乙酯是一种广泛应用于食品、香精、化学、医药和能源等工业的短链酯类。为实现利用丁酸发酵液合成丁酸乙酯,通过络合萃取丁酸发酵液并在萃取相中直接进行脂肪酶催化丁酸和乙醇发生酯化反应,实现了丁酸发酵液萃取-酯化偶联合成丁酸乙酯。首先,确定了三辛胺(TOA)-环己烷为合适的萃取剂和酯化反应的反应溶剂。其次,对反应条件进行优化,在最优反应条件下,萃取相中Novozym 435催化合成丁酸乙酯反应5 h基本达到平衡,酯化率为81.42%,体积产率为65.96 mmol/(L·h);酶在该体系中重复利用6次,酯化率仍未见明显降低,维持在85.40%-87.83%之间。100 m L丁酸发酵液通过萃取-酯化后,丁酸乙酯相对于丁酸的得率为0.65 mol/mol。利用丁酸发酵液萃取-酯化偶联合成丁酸乙酯的工艺具有工业应用价值。

Ethyl butyrate is one of the short chain ester, which is widely used in food, flavor, chemical, medicine and energy industry. In order to synthesize ethyl butyrate using butyric acid fermentation broth, butyric acid extraction from fermentation broth and estrification catalyzed by Novozym 435 in the extractive phase was studied. Tri-n-octylamine （ TOA ） ＋ cyclohexane were adopted as extractive agent and esterifieation reaction medium. Under the optimum conditions, the esterification reaction in the extractive phase had approached equilibrium in 5 h, the corresponding esterifieation yield was 81.42% and productivity was 65.96 mmol/ （ L· h ） . Good operational stability of Novozym 435 in this reaction system was observed. Ethyl butyrate yield relative to butyric acid was 0.65 mol/mol, which ethyl butyrate was synthesized by 100 mL butyric acid fermentation broth extraction-esterification coupling. These results suggest that synthesis of ethyl butyrate by butyric acid fermentation broth extraetion-esterification coupling could realize the scale-up industrial production.