稻殼灰資源化製備中孔洞矽質循環材料應用於甲苯吸附之研究

Abstract

由於資源短缺、廢棄物處置及空氣污染等問題，本研究嘗試將廢棄稻殼資源化再利用，分別以水熱法及噴霧乾燥法製備中孔洞分子篩之高附加價值循環材料，並探討孔洞材料對大分子徑、低極性的甲苯VOCs之吸附能力及反覆吸脫附性。 本研究以稻殼萃取高純度矽源搭配雙性區塊共聚合物F127 (EO106PO70EO106, Pluronic F127, BASF)為模板，透過水熱法合成具中/微孔洞結構之RSBA-16，以及透過噴霧乾燥法製備中孔洞矽質顆粒作為甲苯之吸附劑，並調整界面活性劑與二氧化矽莫耳比例，尋求最佳甲苯吸附之孔洞結構。將製備材料與市售商用沸石一同進行甲苯吸附試驗，結果顯示市售商用沸石NaY具有最高的甲苯飽和吸附容量(153 mg/g)，RSBA-16略低於NaY飽和吸附容量(147mg/g)，但於後續反覆吸脫附的再生性實驗中，NaY劣化情形嚴重，至第五次吸附試驗工作吸附量已降至初始一半，而本研究製備之RSBA-16經十五次反覆循環吸脫附試驗其工作吸附量仍無明顯衰退。 RSBA-16、RSBA-15與RMCM-41具有相近之高比表面積，一般孔洞材料具備大比表面積時，可以提供更多活性吸附位置，增加甲苯吸附能力，而在相同比表面積下，具有較多微孔比表面積將有助於提升甲苯吸附能力，而RSBA-16(147 mg/g)同時具備高比表面積及高微孔比表面積，其甲苯吸附量遠高於RSBA-15(105 mg/g)及RMCM-41(80 mg/g)。此外RSBA-16其製備成本與RSBA-15相近，並遠低於RMCM-41。故經過吸附效能、製備成本與再生測試後，RSBA-16具有最佳的吸附劑應用潛力。

In order to solve the problems of resource shortage, waste disposal and air pollution, the rice husk becomes a valuable agriculture waste resource which can be made into various kinds of energy products and circular materials to solve this problem. This study synthesised mesoporous silica materials by hydrothermal method and spray drying method respectively using rice husk ash derived silica. And the ability of toluene by these porous material were investigated. This study used the rice husk ash derived silicate precursor solution and the non-ionic surfactant of Pluronic F127 to synthesis RMCM-41, RSBA-15 and RSBA-16 by hydrothermal method. And similar materials were used to synthesize mesoporous silica particles by spray drying method. These mesoporous materials were applied to toluene VOCs adsorption and the results were compared with those of zeolites. It showed that there were two adsorbents with higher adsorption capacity than the other adsorbents in toluene adsorption tests. Zeolite NaY showed the highest capacity(153 mg/g), And the capacity of mesoporous material RSBA-16(147 mg/g) was a little lower than NaY. But NaY showed significant decay during cyclic toluene adsorption-desorption test, which was only half capacity of NaY after 5 times cyclic test. The result also indicated that RMCM-41, RSBA-15 and RSBA-16 possessed close values of specific surface area. But RSBA-16 shows much higher adsorption capacity of toluene as compared to other mesoporous materials. The main reason might be owing to its specific surface area presented in micropore range that determined the superiority of toluene adsorption capacity of RSBA-16 adsorbents (147 mg/g) over other adsorbents such as RMCM-41 (80 mg/g) and RSBA-15 (105 mg/g). The results suggested that RSBA-16 which had high adsorption capacity, high cyclic stability and relatively low chemical cost can be considered as a potential adsorbent for toluene control.