復合萃取精餾分離乙酸乙酯-乙醇-水混合體系的研究

摘  要

    本文綜述分析了國內外有關乙酸乙酯一乙醇一水體系分離現狀，提出了復合萃取精餾工藝流程，選擇水為分離乙酸乙酯和乙醇的萃取劑，甘油為分離乙酸乙酯和水的萃取劑。

采用氣相色譜法測定乙酸乙酯、乙醇、水在甘油中的無限稀釋活度系數，用單參數法關聯乙酸乙酯-甘油、乙醇-甘油、水-甘油二元體系的模型參數。設計單級循環式汽液平衡釜，系統的測定了乙酸乙-乙醇、乙醇-水、乙酸乙酯-乙醇-水、乙酸乙酯-乙醇-甘油、乙醇-水-甘油及乙酸乙酯-乙醇-水-甘油體系的VLE，采用最小方差法關聯Wilson, UNIQUAC， NRTL， Margules，Van Laar模型中該體系的相互作用參數。

模擬結果表明：Wilson模型關聯誤差最小，同時建立了二元、三元、四元模擬框圖并用NEWTON-RAPSON法關聯二元、三元、四元汽液平衡數據，并與實測數據進行比較。為復合萃取精餾模擬計算及進一步實驗研究提供了理論依據和基礎數據。

關鍵詞：萃取劑，復合萃取精餾，甘油，汽液平衡，模型參數

Abstract

    The recent processes of separation ethyl acetate-ethanol-water mixture were reviewed in this paper. Azeotropic distillation，membrane separation，liquid-liquid extraction, extractive distillation processes were studied and discussed. On the basis of predecessors，the composite extractive distillation was put forward first by which high purity ethyl acetate can be obtained one time.

The interaction of solvents，ethyl acetate，ethanol and water were studied in detail, relative volatility of ethyl acetate/ethanol and ethyl acetate/water were tested under different solvents. Combined with other influencing factors，water was selected as extractive agent for ethyl acetate-ethanol system and glycerol for ethyl acetate-water system. VLE  data  of  ethanol-water, ethyl acetate-ethanol and ethanol-ethyl acetate-water, ethanol-water-glycerol, ethyl acetate-ethanol-glycerol and ethanol-ethyl acetate-water-glycerol were tested by the simple single equilibrium caldron .The interactive parameters of Wilson, UNIQUAC, NRTL, Margules. Van Laar equation were correlated by the method of  Minimum Variance .The results showed that Wilson equation had the minor absolute error. Diagram of two phases system simulation calculation, Diagram of three phases system simulation calculation and Diagram of four phases system simulation calculation were given，the binary，ternary and quaternary VLE data were simulated according to interactive parameters. The results of calculation data were coincided with experiment data, and providedbasic data for the separation calculation of ethyl acetate-ethanol-water.

The paper can provide theoretical basis and industrial produce for the simulation and calculation of composite extractive distillation and further studies on experiments.

Keywords: Extraction agent；Composite extractive distillation；Glycerol；VLE；Model parameter

目   錄

1概述1

1.1  前言1

1.2  國內外研究現狀及趨勢4

2  復合萃取溶劑的篩選11

2. 1  國內外萃取劑篩選現狀11

2. 2  復合萃取劑篩選13

2. 3  實驗部分15

3  汽液平衡數據的測定及關聯19

3. 1  概述19

3. 2  實驗方案篩選19

3. 3  無限稀釋活度系數的測定20

3. 4  汽液平衡數據的測定22

3. 5  小結35

結論36

參考文獻37

致謝40