Insights into membrane fouling of a side-stream ceramic membrane reactor for phenol hydroxylation over ultrafine TS-1
Insights into membrane fouling of a side-stream ceramic membrane reactor for phenol hydroxylation over ultrafine TS-1
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DOI：
10.1016/j.cej.2013.11.049
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发表时间：
2014-03-01
影响因子：
15.1
通讯作者：
Chen, Rizhi
中科院分区：
文献类型：
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作者：
Jiang, Hong;Jiang, Xiulong;Chen, Rizhi
以超细钛硅分子筛TS-1（TS-1）为催化剂，H2 O2为氧化剂，建立了侧流陶瓷膜反应器，用于苯酚连续羟基化制备苯二酚和对苯二酚。通过设计一系列的过滤实验，基于反应混合物的气相色谱/质谱（GC/MS）分析的膜污染机理进行了详细的研究。采用场发射扫描电子显微镜（FESEM）和能量色散X射线能谱（EDS）对膜表面形貌和化学性质进行了表征。结果表明，反应物苯酚和目标产物邻苯二酚、对苯二酚对膜污染影响不大，但目标产物过氧化副产物对苯醌对膜污染起重要作用。TS-1颗粒和过氧化副产物在膜表面形成的滤饼是造成膜污染的主要原因。提出了一种有效的膜污染清洗方法，可使污染膜的纯水通量恢复95%以上。(C)2013爱思唯尔有限公司版权所有。
A side-stream ceramic membrane reactor was established for continuous phenol hydroxylation to dihydroxybenzene including catechol and hydroquinone over ultrafine titanium silicalites-1 (TS-1) catalysts with H2O2 as the oxidant. The membrane fouling mechanisms were investigated in detail by designing a series of filtration experiments based on the gas chromatography/mass spectrometry (GC/MS) analysis of the reaction mixtures. The field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDS) were used to reveal the surface morphology and chemical nature of the fouled membranes. It is found that the reactant (phenol) and the target products (catechol and hydroquinone) have little influence on membrane fouling, but the overoxidation by-products of target products, such as p-benzoquinone, play an important role in membrane fouling. The filter cake formed on the membrane surface composed of the TS-1 particles and the overoxidation by-products is the main reason of membrane fouling. An efficient cleaning strategy of fouled membrane was also proposed, which leads to an over 95% recovery of pure water flux of the fouled membranes. (C) 2013 Elsevier B.V. All rights reserved.