以二氧化碳及水蒸氣物理活化法製備玉米穗軸、香菇蒂及甘蔗渣活性碳之吸附性質與水活性之探討

Investigation on Water Activity and Absorption Properties of Activated Carbons Prepared from Corn Cob, Mushroom Stalk and Bagasse Pith Using Methods of Physical Activation with CO2 and Steam

吳韋倫(Wei-Lun Wu) ； 吳思敬(She-Ching Wu) ； 林翰謙(Han-Chien Lin)

《嘉大農林學報》 7卷1期 (2010/02) Pp. 1-15

https://doi.org/10.29891/JAFNCU.201002.0001

摘要

本研究以二氧化碳及水蒸氣爲活化氣體之物理活化法製備農業廢棄物玉米穗軸、香菇蒂與甘蔗渣等之活性碳，並比較三者於不同製備條件活性碳之物理吸附性質及其水活性等。結果顯示，三者農業廢棄物活性碳收率介於9.8-25.1%，且以二氧化碳活化者收率較高，約爲11.5-25.1%。碘值結果可知，以水蒸氣活化法在活化溫度800℃及850℃之甘蔗渣活性碳的吸附性能較佳，皆達1009mg/g，而亞甲基藍吸附值最佳者為以水蒸氣活化法在活化溫度800℃之甘蔗渣活性碳，可達540.5mg/g。BET比表面積方面，以甘蔗渣活性碳於水蒸氣活化法在活化溫度800℃者爲最大值(894.69平方公尺/g），而各活性碳以BDDT分類法之吸脫附等溫線而言，皆屬TypeⅠ型之微孔隙較多者，且因其皆具遲滯輪現象，又依IUPAC分類法可知，各製備活性碳皆屬於具有裂縫狀孔隙之H4類型。水活性評估結果得知，三者農業廢棄物活性碳之水活性值範圍介於0.191-0.546，且在不同活化溫度（750、800及850℃）下，皆以水蒸氣活化者較以二氧化碳活化者低。依上述結果，以不同活化法所製備之三種農業廢棄物活性碳，應可初步做爲食品防潮劑之原料。

關鍵字

玉米穗軸 ； 香菇蒂 ； 甘蔗渣 ； 活性碳 ； 二氧化碳物理活化法 ； 水蒸氣物理活化法 ； 水活性

並列摘要

The study used corn cob, mushroom stalk and bagasse pith of agricultural wastes as the specimens to prepare various activated carbons (Acs) by using the methods of physics activation with either carbon dioxide (CO2) or steam at different activated temperature. The physical absorption properties and the water activity of Acs were compared by based on their preparation conditions. The results obtained that the yield for three kinds of agriculture wastes of Acs was 9.8-25.1 %, and the yield of Acs, about 11.5-25.1%, by using CO2-activation was higher than that by using steam-activation. For the iodine number tests, the best one was bagasse pith activated carbon (Ac) by using steam-activation at 800℃ and 850℃ of activated temperature, and both them were all reached to about 1009 mg/g. From the results of adsorbed value on methylene blue number tests, the best one was bagasse pith Ac by using steam-activation at 800℃, and its value was reached to about 540.5 mg/g. In the specific surface area tests, the largest value (894.69 m^2/g) was the bagasse pith Ac by using steam-activation at 800℃. For all Acs, according to the classification of BDDT (Brunauer-Deming-Deming-Teller), their adsorption/desorption isotherms were the type Ⅰ with micropore, and were belong to the crack shape pores of H4 type in accordance with the IUPAC (International Union of Pure and Applied Chemistry) classifications of hysteresis loop. For evaluation of water activity (Aw), the results of Aw for Acs prepared from three kinds of agricultural wastes were 0.191-0.546. The Aw of Acs at different activated temperatures (750, 800 and 850℃) by using steam-activation was lower than that by CO2-activation. From the above results, it is indicated that the Acs prepared from three kinds of agricultural wastes are able to as a moisture-proof material for food industry using.

並列關鍵字

Corn cob ； Mushroom stalk ； Bagasse pith ； Activated carbon Ac ； Method of physical activation with CO2 ； Method of physical activation with steam ； Water activity Aw