以溶劑萃取法自氯黴素模擬製程廢水中回收醋酸之研究

Recovery of Acetic Acid from Simulated Process Streams of Chloromycetin Production Using Solvent Extraction

吳榮宗(Rong-Tzong Wu)

指導教授 ： 莊瑞鑫

元智大學/工程學院/化學工程與材料科學學系/碩士(1997年)

摘要

本論文旨在研究醋酸的溶劑萃取；系統共分為二個部份，分別為萃取平衡及萃取動力學，所使用的萃取劑為氯化三辛基甲基胺(Trioctylmethylammonium chloride，Aliquat 336）、三級胺與四級胺混合物(Tri- -alkyl amines，Alamine 336)、三辛基氧化膦(Trioctylphosphine oxide，TOPO)與磷酸三丁酯 (Tri-n-butyl phosphate，TBP)，稀釋劑為二甲苯 (Xylene)。
在萃取平衡方面，首先在溫度 15 ~ 45℃ 下測定醋酸在有機相的分配比，發現在同樣的條件下的萃取效果為Aliquat 336最佳、TBP最差。在萃取平衡溫度效應部分，發現此萃取系統的溫度影響並不明顯。而在反萃取平衡部分，發現碳酸鈉(Sodium carbonate， )最適合當反萃取液，其在不同的萃取劑溶液中，效果皆不錯。
在動力學方面，本文以一薄膜傳送槽 (Membrane-based permeation cell) 來探討萃取系統的界面動力學；首先測定出正反向的質傳速率，其次則估算出在整個系統中各個成分的擴散係數，並由擴散係數求出其質傳係數，再扣除擴散阻力後，即可得到薄膜的界面反應濃度，同時可求得真正的 (Intrinsic) 反應速率式與其速率常數，其結果如下：
正向萃取 ， ；
正向萃取 ， 。
另外，由TBP的溫度效應與速率常數關係中求得正萃取反應的活化能為22.63 kJ/mol (5.41 kcal/mol)。

關鍵字

溶劑萃取 ； 醋酸 ； 萃取劑 ； 薄膜 ； 質傳速率

並列摘要

Equilibrium and kinetics of solvent extraction of acetic acids was investigated in this study. Trioctylmethylammonium chloride (Aliquat 336), Tri- -alkyl amines (Alamine 336), Trioctylphosphine oxide (TOPO) and Tri-n-butyl phosphate (TBP) are used as extractants, on the other hand xylene is the diluent.
In the equilibrium studies, first of all we detect that distribution ratio of acetic acid in the range of 15℃~25℃.Aliquat 336 is best and TBP is worse of their extraction effect under the same conditions. In temperature effect, in this system it is not obvious. In stripping , is most suitable to be an stripping agent,and it also has good result in the different extractants.
In the kinetic studies, the membrane-based permeation cell was adopted to study the interfacial transfer kinetics. At first, the forward and backward extraction rates were measured, and then the individual mass transfer coefficients estimated to be deducted by diffusion coefficients of each species. In addition, eliminating the contribution of diffusion resistance, we could obtain the intrinsic chemical reaction expression occurring in organic phase interface, and also the rate constants. The results were as follows: ， and ，
Finally, the activation energy for extraction with TBP could also be obtained to be 22.63 kJ/mol (5.41 kcal/mol).

並列關鍵字

solvent extraction ； Acetic acid ； extractant ； membrane ； extraction rate

參考文獻

劉英俊，汪金追" 生物化學工程學 "，中央圖書出版， (1987) 。

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Bizek, V., Horacek, J., Rericha, R. and Kousova, M. Amine Extraction of Hydroxycarboxylic Acids. 1. Extraction of Citric Acid with 1-Octanol/n-Heptane Solutions of Trialkylamine. Ind. Eng. Chem. Res., 31, 1554-1562 (1992) .

Bohrer, M. P. Diffusional Boundary Layer Resistance for Membrane Transport. Ind. Eng. Chem. Fundam., 22, 72-78 (1983)