探討非傳統吸附劑去除酒精中微量水分之研究

The Use of Non-convectional Adsorbent to Separate a Small Amount of Water Content from Ethanol

王冠翔(Wang-Kuang Hsiang)

指導教授 ： 鍾財王

中原大學/工學院/化學工程學系/碩士(2008年)

https://doi.org/10.6840/cycu200800355

摘要

本研究成功利用實驗室自製之重量法吸附平衡設備，得到分子篩3A、馬鈴薯澱粉、玉米澱粉、樹薯澱粉、纖維素及二氧化鈦奈米線之水氣與乙醇在24oC下之恆溫吸附曲線。由氣相吸附實驗的結果，發現在相對壓力約0.6時，吸附劑之吸附水量與吸附乙醇量之比值，以馬鈴薯澱粉最高，其值為64.138。其次依序為纖維素、玉米澱粉、樹薯澱粉、二氧化鈦奈米線，最後為分子篩3A。由恆溫吸附曲線，發現非傳統吸附劑相較於分子篩3A對水與乙醇有良好的選擇性。
本研究使用Langmuir、BET、Mod-BET、Halsey、Smith、Henderson、Oswin、Ferro-Fintan、GAB和Peleg之恆溫吸附模式，回歸氣相吸附實驗數據。並利用平均相對偏差百分比(E)來判斷回歸模式是否準確的描述實驗所得的恆溫吸附曲線。由回歸結果得知，Langmuir模式對分子篩3A之回歸結果較佳，澱粉吸附劑以GAB、Ferro-Fintan和Peleg模式較好，其中以四參數之Peleg模式最佳。纖維素以Smith模式效果最好，但這些模式皆無法確切的描述二氧化鈦奈米線的吸附行為。
在液相吸附實驗中，觀察到各吸附劑在乙醇濃度90wt%時，皆有最高的移除水量，隨著乙醇濃度下降至50wt%及15wt%，所有吸附劑的移除水量也隨之銳減。在乙醇濃度90wt%，分子篩3A的吸附效果較這些為固定化之澱粉材料與纖維素之吸附劑來的好，但在15wt%與50wt%時，除了馬鈴薯澱粉之外，其於的澱粉材料與纖維素都有較佳的吸附效果。而二氧化鈦奈米線在液相吸附時，有較佳的吸附效果。

關鍵字

水 ； 吸附 ； 乙醇 ； 恆溫吸附曲線 ； 纖維素 ； 澱粉

並列摘要

The potential of using bio-based adsorbent to remove low water content from ethanol was assessed. In this study, adsorption isotherms for zeolite 3A, potato starch, corn starch, cassava starch, cellulose ,and titania nanowires were determined at 24oC using the gravimetric method. Experiment results indicated that the water adsorption ratio(g water/g ethanol) of potato starch is the highest with the value 64.138 at relative pressure equal to 0.6, the lowest is zeolite 3A. It was found that this non-conventional adsorbent had good selectivity in ethanol-water solution in comparison with zeolite 3A.
The data obtained were fitted to several model including Langmuir, BET, Mod-BET, Halsey, Smith, Henderson ,Oswin, Ferro-Fintan ,GAB ,and Peleg. Analysis showed that the Langmuir model better described the experimental data for zeolite 3A. GAB, Ferror-Fintan, and Peleg model can describe the experiment data of starch-based adsorbent well. The Peleg model with four parameters gave the best fit on the starch-based adsorbent. The result of cellulose data fitted by the Smith model was better than with the other models.
In these liquid phase experiments, all adsorbents had good adsorptive capacity at 90 wt % ethanol. When the ethanol concentration was decreased to 50 wt% and 15 wt%, the amount of water removed for all adsorbents. For ethanol 90wt%, the zeolite 3A adsorptive capacity is greater than starch-based and cellulose adsorbent which is not immobilization. But, bio-based adsorbent have good adsorptive capacity except for potato starch, in ethanol concentration 15 wt% and 50 wt%. However, titania nanowires has good adsorptive capacity in liquid phase.

並列關鍵字

adsorption ； water ； starch ； cellulose ； isotherm ； ethanol

參考文獻

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