粉煤灰源NaY沸石的制备及其对乙酸乙酯的吸附性能研究  

Study of the preparation of NaY zeolite from coal fly ash and its adsorption performance of ethyl acetate

作　　者：李艳霞 何文宇 成海荣 黄皓旻 付名利 吴军良 牛晓君 胡芸 叶代启 LI Yanxia;HE Wenyu;CHENG Hairong;HUANG Haomin;FU Mingli;WU Junliang;NIU Xiaojun;HU Yun;YE Daiqi(School of Environment and Energy,South China University of Technology,Guangzhou 510006;Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control,Guangzhou 510006;National Engineering Laboratory for VOCs Pollution Control Technology and Equipment,Guangzhou 510006)

机构地区：[1]华南理工大学,环境与能源学院,广州510006 [2]广东省大气环境与污染控制重点实验室,广州510006 [3]挥发性有机物污染治理技术与装备国家工程实验室,广州510006

出　　处：《环境科学学报》2021年第12期4803-4811,共9页Acta Scientiae Circumstantiae

基　　金：广州市科技计划项目(No.201804020026);国家重点研发计划(No.2018YFB0605200);国家自然科学基金(No.51878293,21777047);广东省自然科学基金(No.2017B090901049)。

摘　　要：采用粉煤灰合成沸石的方法既经济又环保,在乙酸乙酯吸附领域中具有巨大应用前景.遵循节能减排、废物再利用的环保原则,探索了3种不同Si/Al比的粉煤灰、结晶温度、结晶时间和碱浓度4个因素对合成NaY沸石的影响.XRD、氮气吸脱附实验及ICP结果表明,Si/Al比和水热结晶温度对高比表面积NaY沸石的合成影响最大.Si/Al比在1左右的粉煤灰合成的沸石比表面积较低,且晶形中存在大量的NaA沸石,而Si/Al比在2左右的粉煤灰合成了高比表面积且纯度较高的NaY沸石;3种粉煤灰均在65℃下合成NaY沸石,但在105℃下完全转化为方钠石.实验优化结果表明,最优合成条件为采用Si/Al为2左右的粉煤灰,在2 mol·L^(-1)碱浓度、65℃水热温度下结晶12 h.该条件下合成的NaY沸石比表面积高达654.86 m^(2)·g^(-1)(比表面积最高的粉煤灰源沸石之一),是原粉煤灰比表面积的22倍左右,对乙酸乙酯的吸附量也由15.4 mg·g^(-1)增至108.2 mg·g^(-1).Zeolite synthesized from coal fly ash represents an environmentally friendly and economical strategy,which has great prospects in the application of ethyl acetate adsorption.Based on the principles of energy conservation,emission reduction and waste recycling,the effects of three different Si/Al ratios of coal fly ash,crystallization temperature and time,and alkali concentration on the synthesis of NaY zeolite were explored.The results of XRD,N2 adsorption-desorption isotherms,and ICP exhibit that the Si/Al ratio and hydrothermal crystallization temperature significantly influence the synthesis of NaY zeolite.The one prepared from the coal fly ash with a Si/Al ratio around 1 contains a large amount of NaA in the crystal,showing relatively low surface specific area(SSA),while that with large SSA and high crystal purity was synthesized by the coal fly ash with a Si/Al ratio around 2.In addition,the NaY zeolite could be formed by using three kinds of coal fly ash at 65℃,but it was completely transformed into sodalite at 105℃.After experimental optimization,the use of the fly ash with a Si/Al ratio of about 2 under 65℃for 12 h at an alkali concentration of 2 mol·L^(-1)was defined as the best synthesis condition.The SSA of the as-prepared NaY zeolite is as high as 654.86 m^(2)·g^(-1)(one of the coal fly ash source zeolites with the highest SSA),which is about 22 times of the original coal fly ash.Its adsorption capacity for ethyl acetate also increased from 15.4 mg·g^(-1)to 108.2 mg·g^(-1),indicating the potential practical application.

关 键 词：硅铝比 高比表面积 NAY沸石 粉煤灰 结晶温度 

分 类 号：X701[环境科学与工程—环境工程]