不同溶劑萃取對柳杉疏伐木化學成分及其生物炭孔隙特性之影響

Effects of Different Solvent Extractions on Chemical of Cryptomeria japonica Thinning Wood and Pore Characteristics of Biochar

劉素玲(Su-Ling Liu) ； 鄭森松(Sen-Sung Cheng)

《國立臺灣大學生物資源暨農學院實驗林研究報告》 34卷2期 (2020/06) Pp. 79-95

https://doi.org/10.6542/EFNTU.202006_34(2).0001

摘要

為了解柳杉疏伐木可否作為再生資源推動循環經濟，本研究檢測未處理、熱水及甲醇萃取等三種處理方式下柳杉疏伐木化學組成分之差異及其經三種不同炭化溫度（500、550、600°C）製備之生物炭孔隙特性的不同。研究結果顯示，三種不同前處理柳杉之全纖維素、α-纖維素、酸不可溶木質素和乙醇－甲苯抽出物含量等皆呈顯著性差異。經不同炭化溫度處理之柳杉生物炭之收率介於23.33至25.79%之間，且皆隨著炭化溫度之提高而降低。然而，所有處理生物炭之pH介於6.49-7.55，且皆隨著炭化溫度之提高而增加。三種不同前處理柳杉所製備之生物炭之N_2吸、脫附等溫曲線均屬於TypeI（b）類型，顯示其孔隙結構以微孔為主；BET比表面積介於394.88 - 565.05 m^2/g，以炭化溫度550°C經甲醇萃取者為最高（565.05 m^2/g）。因此，以再生資源推動循環經濟為目標下，回收已萃取之柳杉製備生物炭為一可行之方式。

關鍵字

柳杉 ； 溶劑萃取 ； 化學組成分 ； 生物炭 ； 孔隙性質

並列摘要

To investigate if Cryptomeria japonica thinning wood can be applied to renewable resources for circular economy, this study examined the chemical composition differences of C. japonica thinning wood under three different pretreatments- untreated, hot water and methanol extracted; and analyzed their pore characteristics of the biochars prepared at different carbonization temperatures-500, 550 and 600°C. The results indicated that the contents of holocellulose, α-cellulose, klason lignin and alcohol-toluene extractives of C. japonica all showed significant differences with different pretreatments. The yields of the C. japonica biochars carbonized at three carbonization temperatures ranged from 23.33% to 25.79% and decreased with carbonization temperature. The pH of three biochars ranged from 6.49 to 7.55, and it increased with increasing carbonization temperature. The nitrogen adsorption and desorption isotherms of biochar prepared from different pretreatments were both Type I (b), indicating that micropore was a major pore structure. The specific surface area of three biochars ranged from 394.88 m^2/g to 565.05 m^2/g, and the C. japonica extracted by methanol and carbonized at 550°C showed the highest specific surface (565.05 m^2/g). Therefore, we suggest that recovering the extracted C. japonica to prepare biochar is a feasible method to approach the goal of circular economy with renewable resources.

並列關鍵字

Cryptomeria japonica ； Solvents extracted ； Chemical compositions ； Biochar ； Pore properties