以UV／TiO2程序進行氣相中三氯乙烷分解反應之研究

The Degradation of Trichloroethane in Gas Phase by UV/TiO2 Process

本研究係以化學氣相沈積法披覆二氧化鈦光觸媒於環管狀反應器上，並採用365nm波長之UV燈管置於反應器中央為激發光源，控制因子包括初始濃度、氣體流量、光照強度、溼度及氧氣含量等。實驗採用連續流方式，進行三氯乙烷在異相光催化分解反應中，溼度及氧氣含量對最終產物的影響並了解其礦化情形。由實驗結果顯示，當氧分子增加時，HCl、Cl2和CO2的產量均會隨著增加，但當溼度增加時，除了HCl的產量下降外，Cl2和CO2的產量卻會隨之上升。而由質量平衡的結果可知，三氯乙烷之異相光催化分解的礦化程度不佳，推估三氯乙烷反應後並無完全地轉換為無機產物，而仍有大部分以中間產物的型態存在。

The object of this study was to investigate the effect of moisture and oxygen concentration for trichloroethane in the heterogeneous photocatalytic reaction using a TiO2 catalyst deposited in an annular reactor by the chemical vapor deposition (CVD) method. The UV light source was used a UV lamp with 365 nm wavelength placing in the center of reactor, and the controlled factors included the initial reactant concentration, 5as flow rate, light intensity, moisture, and oxygen concentration. From the experimental results, the production of HCl, C12, and CO2 increased with the increasing oxygen concentration. However, the formation of HCl decreased as the moisture increased. According to the results of mass balance, the minerilzation of trichloroethane in photocatalytic reaction had not a good efficiency, it indicated that there existed a large part of intermediates.