市售備長炭特性之初步研究

Preliminary Study on Characterization of Commercial Bey-Charng Charcoals

「備長炭」為一種碳化木炭，具多孔洞特性結構，可被使用於水質之吸附淨化程序。本研究主要目的係進行市面上備長炭孔洞特性之初步分析調查，並與常用活性碳（基材為椰子殼及煙煤）做一比較，並將前述備長炭及活性碳進行對甲烯藍染料之初步吸附研究，並將其吸附動力數據以假二階反應模式（pseudo-second order model）迴歸分析，所得動力學參數再與其孔洞特性做一比較性探討。研究結果顯示，備長炭BET表面積約為20-40 平方公分／g，遠低於活性碳（BET表面積約為1000 平方公分／g），然而其孔洞大小分佈相當窄，絕大多數集中於2.0 nm以下，即屬微孔性，與活性碳類似。吸附用備長炭（代號：C-2）比燃料用備長炭（代號：C-1）有稍佳的甲烯藍吸附去除效能，符合此二種備長炭孔洞特性分析結果。本研究中亦初步利用假二階反應模式進行吸附動態分析，結果顯示其迴歸相關性甚高。

Bey-Charng charcoal, a carbonized material and characteristics of porous and hard structure, is extensively used as adsorbent for the removal of all impurities from the aqueous solution. The objective of this work was to examine the pore properties of commercial Bey-Charng charcoals, and compare the results with those of commercial granular activated carbons with coconut shell- and bituminous coal- based. Further, a preliminary adsorption of methylene blue onto these Bey-Charng charcoals and granular activated carbons was carried out and analyzed using pseudo-second order model. The results showed that BET surface areas of Bey-Charng charcoals are approximately 20-40 m^2／g, significantly lower than those （about 1000 m^2／g） of granular activated carbons. The pore size distribution of Bey-Charng charcoal revealed a sharp peak at a much lower pore diameter （about 2.0 nm）, implying that its pore property should belong to microporosity like the activated carbon does. In comparison with removal efficiency by methylene blue adsorption, the Bey-Charng charcoal （adsorption use, notation code: C-2） is superior to another Bey-Charng charcoal （fuel use, notation code: C-1）, which is consistent with the results of their pore properties. Finally, it was found that the adsorption process can be well described with the pseudo-second- order model. The kinetic parameters of the model obtained in the present work are in line with the pore properties of the Bey-Charng charcoals and granular activated carbons