利用農業廢棄物以微波活化合成微孔活性碳及探討物化性質

Preparation and Characterization of Microporous Activated Carbon from Agricultural Waste by Microwave-Assisted Activation

黃郁婷(Yu-Ting Huang)

指導教授 ： 席行正

國立臺北科技大學/工程學院/環境工程與管理研究所/碩士(2012年)

https://doi.org/10.6841/NTUT.2012.00245

摘要

本研究利用不同農業廢棄物做為起始原料製備多孔性碳基吸附材，搭配不同活化劑(KOH及ZnCl2)及活化劑比例，配合微波開發出不同物化特性之活性碳吸附劑，期盼能合成多孔隙碳基吸附劑之可行性。本研究之技術具有低成本、新穎性及回收再利用等優勢，並可達到林業廢棄物資源再利用之目的。
本研究結果顯示利用不同微波活化時間搭配不同活化劑和比例，均可成功將銀合歡碳化材及檳榔木碳化材開發為具有高度孔徑發展之活性碳吸附劑。值得注意的是當銀合歡添加KOH與ZnCl2活化後，加入KOH的銀合歡碳化木及檳榔木碳化木BET比表面積皆有明顯上升之趨勢，而孔隙結構均以微孔分佈為主，而觀察活性碳表面發現，其原始材料本身具有植物性質，故能觀察到維管束之構造。特別的是管壁表面存在許多小孔，因此在活化過程中，活化氣體將不斷經由孔洞進入結構，將封閉微孔打開或者在創造一些新的孔隙結構。經適當的微波活化程序後，活性碳之表面BET及微孔表面積均顯著提升，此現象表示已將銀合歡及檳榔木開發為具有微孔結構之活性碳。另外由元素分析結果得知，添加KOH活化後使得銀合歡及檳榔木碳化材之碳含量不斷減少，而氧含量則不斷增加，進一步增加其活性碳表面含氧官能基之含量，而添加ZnCl2後碳含量之所以增加，可能為材料本身脫水反應所造成。本研究結果顯示兩種起始原料皆為開發微孔活性碳之適當材料。

關鍵字

銀合歡 ； 檳榔木 ； 微波活化 ； 活性碳

並列摘要

The study attempts to prepare highly porous activated carbon adsorbent with diverse physical and chemical properties from two agricultural wastes (Leucaena leucocephala and Areca catechu L) with two agents (KOH and ZnC12) at various ratios and activation time. This approach is low-cost, innovative, and able to recycle and reuse the agricultural wastes.
The results of the study showed that with different microwave activation time, activation reagent and ratios, carbonized agricultural waste wood (i.e., char) can be developed into highly microporous activated carbon. After adding KOH, the BET surface area of both Leucaena leucocephala and Areca catechu L char increased pore structure is mainly microporous. Since the starting precursors are natural plants, the structure of vascular can be clearly observed under a scanning microscope. The surface of the wall contains many small pores, through which activation agents can enter the structure during activation to open up the closed micropore or create new pore structure. After the microwave activation, both the BET the micropore surface area of resulting activated carbon increased, indicating that Leucaena leucocephala and Areca catechu L woods have been developed into activated carbon with well-developed micropore structure. The elemental analysis showed that the carbon content of Leucaena leucocephala and Areca catechu L wood activated carbons reduced after KOH activation. The increasing oxygen content suggested a increase in the amount of oxygen functional groups on activated carbon surface that may enhance the hydrophilicity. In contrast, the addition of ZnCl2 increased the oxygen and may dehydrate the materials. The study suggests that both starting agricultural wastes are ideal for developing microporous activated carbon.

並列關鍵字

Leucaena leucocephala ； Areca catechu L ； microwave assisted ； activated carbon

參考文獻

呂明倫、黃靜宜、鍾玉龍，恆春半島銀合歡入侵分布之動態與區位分析，航測及遙測學刊，2009，14(1):1-9。

黃玲娟，檳榔幹材不同部位之解部特徵與化學成分之研究。2005，11-18。

Jones, D. A., Lelyveld, T. P., Marvofidis, S. D., Kingman, S. W., Miles, N. J., “Microwave Heating Applications in Environmental Engineering - A Review,” Resources, Conservation and Recycling, 2002, vol. 34, 75-90.

Fang, C. S., Chang, B. K. L., Lai, P. M. C., Klaila, W. J., “Microwave demulsification,” Journal of Chemical Education, 1988, vol. 73, 227-239.

Abu-Samia, A., Morris, J. S., Koirtyohann, S. R., “Wet ashing of some biological samples in a microwave oven,” Analytical Chemistry, vol. 47, 1475-1477.