催化氧化反應及捲氣式反應器之研究

Catalytic Oxidation of Industrial Wastewater in a Gas-Induced Reactor

詹煌義(Chan Huang Yi)

指導教授 ： 林勝雄

元智大學/工程學院/化學工程與材料科學學系/碩士(2000年)

摘要

催化氧化反應器為一高氣體利用率的系統。本研究採用活性碳纖維，利用其高吸附量、快吸附速度的特性以及臭氧之強氧化力的優點，來進一步提升臭氧加柱狀活性碳之系統的效能。
在批次反應的研究中，討論不同操作條件（臭氧質量流率、活性碳填充量、pH值），對於臭氧加活性碳纖維系統之處理效果影響。連續式反應的討論則是著重在前處理步驟─化學混凝的應用，對連續式反應的影響。化學混凝法的應用，可有效的減輕催化氧化反應處理染整廢水的負荷及成本，是為一實際可行之方案。
多因子配置實驗（實驗設計）的研究是採用統計的理論，應用於量化因子（葉片轉速、活性碳纖維填充量、臭氧質量流率、反應時間）對於催化氧化反應的影響。發現以上四個主要因皆有99 %的信心可說其影響效果顯著；在交互作用部份則都是不顯著的要因。再者，利用迴歸分析法獲得其應答曲面的函數，以此可求得催化氧化反應操作條件之最適組合。同時，亦可利用應答曲面來預測不同操作條件之下的處理成效。
動力學方面，以臭氧質量流率變化及不同活性碳纖維填充量做動力學模擬研究。在本實驗中所討論之四種動力學模式（指數、總和、通式及複式動力學模式）之中，發現複式及通式動力學模式是可很適切的描述催化氧化反應的反應機制。
反應器設計及規模放大的討論，無因次數的分析，則是了解攪拌動力之動力曲線的變化。嘗試以臨界轉速的研究來定義捲氣現象。氣體滯留率(Gas Holdup)的研究，無非是想探究反應器中有多少之氣體被留在液相之中。最後，考慮氣、液、固三相的操作比率，以研究在規模放大時，定比率放大是否為可行的方式。

關鍵字

催化氧化反應 ； 捲氣式反應器 ； 工業廢水 ； 實驗設計

並列摘要

Catalytic oxidation reaction is a process that achieves a maximum utilization of oxygen in a catalytic environment. In the present research, the activated carbon fiber (ACF) and ozone were combined to achieve a maximum efficiency of the catalytic oxidation process by capitalizing the adsorption and catalytic oxidation capabilities of ACF.
In the batch experimental test, investigations were made to examine the treatment efficiencies of industrial wastewater by such a process under various operating conditions including the ozone mass flow rate, amount of ACF and pH. In the continuous tests, chemical coagulation was adopted as a pretreatment measure of the industrial wastewater. Test results indicated that chemical coagulation offers an efficient means for complimenting the catalytic oxidation reaction process.
Multi-factor experimental design was employed in the present study to help search for the optimal operating conditions that include the mixer speed, amount of ACF, ozone mass flow rate and the reaction time. Analysis of experimental design showed that the effects of these four operating variables are strong with 99 % confidence. However, the interactions of these four variables on the treatment efficiency are not evident. The multi-factor response surface equation obtained from the experimental tests permitted easy determination of optimal operating conditions.
Kinetic studies were also attempted to investigate the reaction mechanism of the catalytic oxidation process. Several kinetic models, including exponential, Lumped, generalized and complex kinetics, were considered for describing catalytic oxidation reaction. The generalized and complex kinetics were found to represent well the reaction process.
For process scale-up and reactor design, dimensionless analysis was made to correlate the power number and the mixer speed. The dimensionless correlation allows easy scale-up of experimental apparatus. Test results shows that the correlation is represented by two line segments that join at a critical mixer speed for gas induction onset. Other related aspects, like gas holdup, in the liquid phase were also studied in the experimental tests.

並列關鍵字

Catalytic Oxidation ； Gas-Induced Reactor ； Industrial Wastewater ； Experimental Design

參考文獻

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