固定化生物吸附材於乙醇-水之吸附選擇性探討

Immobilization of starch sorbents for the selective adsorption of ethanol-water mixtures

劉祐維(Yu-Wei Liu)

指導教授 ： 鍾財王

中原大學/工學院/化學工程研究所/碩士(2010年)

https://doi.org/10.6840/cycu201000328

摘要

酒精汽油為生質酒精添加在石化汽油中，可以取代高污染的含鉛汽油作為替代能源，但添加在汽油中的酒精其含水量必須小於0.5wt%，若水含量超過0.5wt%現有的引擎就必須有所調整。目前工業上大多以分子篩3A當作選擇性吸附材，由於其吸附選擇性及再生效率較差，所以近年來有些學者開始利用澱粉等材料來當作吸附材。未經處理的澱粉吸附材在吸附水分子後，膨潤及糊化等問題造成澱粉再生後的吸附力大幅下降，因此，本研究將澱粉固定化在矽膠基材上，以求解決澱粉在吸附上所遇到的問題。本研究利用Sol-Gel法成功將澱粉固定化在矽膠基材上，利用能量散佈光譜儀 (Energy - dispersive X-ray, EDX)分析證實澱粉能成功地被固定在矽膠基材中，由分析結果可知當矽膠與澱粉的摻混比為一時摻混效果最佳。由氣相吸附測試結果發現固定化澱粉對水與乙醇的吸附選擇比(Water/Ehanol uptake)是傳統吸附材分子篩3A的2.4倍。此外，經過固定化後的澱粉再生後吸附能力比未經處理澱粉高出約36.3%。實驗數據經等溫吸附方程式迴歸後，比較迴歸常數發現 Langmuir model為大部分吸附材吸附行為的最佳描述。基於上述結果固定化澱粉表現出更好的吸附選擇比和再生能力。因此，本研究製備的固定化澱粉可能在填充塔酒精脫水系統中具有更好的應用價值。

關鍵字

乙醇 ； 溶膠-凝膠 ； 等溫吸附曲線 ； 水 ； 生物吸附材 ； 固定化

並列摘要

Ethanol gasoline is a mixture of anhydrous ethanol and diesel, which may replace gasoline contain lead, and serve as bio-fuel. If the water content of ethanol is less than 0.5 wt %, and it may be blended into gasoline used in engine. Otherwise, the engine should be redesigned. Zeolite 3A is a widely used adsorbent in industry for ethanol dehydration. However, it has a low efficiency with adsorption selectivity and regeneration. Recently, some investigators have tried to use biomass based materials as a replacement to Zeolite 3A, such as starch. However, starch powder was recovered after adsorption with water vapor, and significant decrease of its adsorption ability was observed. In the present study, starch was immobilized into silica gel using sol-gel method for solving these problems. Results of energy-dispersive x-ray analysis showed that the starch particles are successfully immobilized into silica gel. The selectivity of the new material was found to be 2.4 times than that of Zeolite 3A. The adsorption ability of the new material increased by about 36.3% compared to that of raw starch. Furthermore, data using isotherm models and R-square values analysis suggested that Langmuir model is the most suitable model for this adsorbent material. Based on the above results, the immobilized starch was proven to be superior in terms of adsorption selectivity and regeneration ability over other adsorbents. Thus, this adsorbent material might be a potential adsorbent for application in ethanol dehydration systems.

並列關鍵字

Isotherm ； Alcohol ； Sol-Gel ； Bio-adsorbent ； Immobilize

參考文獻

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