旋轉反應器在光觸媒的應用之製程特性與規模放大

旋轉反應器 (RDR) 在光觸媒降解之應用近年來受到極高的重視，其不僅可避免懸浮型光觸媒反應器需在操作後需分離光觸媒粉體的問題，並藉由旋轉盤旋轉，使有機污染物可高度均勻混合並產生極薄的液膜，因此光穿透率可顯著提升而大幅極高光反應速率，避免塗佈型光觸媒反應器的常見之質傳限制問題，甚至效能可超越懸浮型光觸媒反應器。本研究主要分成三部分。首先，將結合旋轉盤流體力學與動力學模式，利用甲基橙在紫外光下之降解速率觀察旋轉反應器之製程特性。實驗結果顯示，在僅有1.6秒之轉盤滯留時間下，甲基澄之光降解轉化率高達55%。此外，藉由轉盤旋轉，不僅可同時增加光反應速率及質傳速率，並能使整體光降解反應速率位於光反應限制區，不受質傳限制之影響。第二，本研究進一步提出旋轉反應器對有機染料的光降解機制，與質傳之機制進行比較，並成功使用軟體模擬轉盤上濃度之變化。結果顯示，模擬之反應機制進一步證明在轉速提升之後能避免質傳的影響。最後，本研究提出旋轉反應器在製程放大的便利性與可能性，其可藉由轉盤之放大而大幅提升光降解之轉化率。

關鍵字

二氧化鈦；旋轉反應器；甲基橙；光降解反應；高級氧化程序

並列摘要

Rotating-disk-reactor (RDR) has been received much attention in photocatalysis, which not only avoids the difficult separated process between TiO2 and solution, but would be expected to possess better performance even than the suspension photocatalytic reactors. Three main objectives of this work are to be noted. Firstly, we investigated the process characteristics of RDR on degrading methyl orange (MO) by combining the kinetics model and fluid dynamics model we proposed. The results show that the conversion of MO was up to 55% within 1.6s of retention time. With disk rotating: (1) The photocatalytic reaction rate was greatly improved by light penetration only through the micro-scale liquid film. (2) The mass transfer rate was increased significantly and the reaction is shifted to the photocatalytic reaction rate limitation region. Secondly, the intrinsic mechanism of photocatalytic reaction have been presented and simulated. Last but not least, the possibility of scale-up is discussed in our research. Based on our model, the optimal condition of photocatalytic process could be simply attained by calibrating several parameters, including flow rate, rotating speed, disk size and light intensity.

並列關鍵字

TiO2 ； Rotating-disk-reactor ； Methyl orange ； Photocatalysis ； Adcanced Oxidation Process

參考文獻

76. C. F. Lo, J. C. S. Wu, "Preparation and characterization of tio2-coated optical-fiber in a photo reactor", Journal of the Chinese Institute of Chemical Engineers; 36, 119-126 (2005).

1. Y. Parent, D. Blake, K. MagriniBair, C. Lyons, C. Turchi, A. Watt, E. Wolfrum, M. Prairie, "Solar photocatalytic processes for the purification of water: State of development and barriers to commercialization", Solar Energy; 56, 429-437 (1996).

2. S. M. Rodriguez, C. Richter, J. B. Galvez, M. Vincent, "Photocatalytic degradation of industrial residual waters", Solar Energy; 56, 401-410 (1996).

3. M. R. Hoffmann, S. T. Martin, W. Y. Choi, D. W. Bahnemann, "Environmental applications of semiconductor photocatalysis", Chemical Reviews; 95, 69-96 (1995).

4. P. Wyness, J. F. Klausner, D. Y. Goswami, K. S. Schanze, "Performance of nonconcentrating solar photocatalytic oxidation reactors .1. Flat-plate configuration", Journal of Solar Energy Engineering-Transactions of the Asme; 116, 2-7 (1994).

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旋轉反應器在光觸媒的應用之製程特性與規模放大

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