低温等离子体催化降解甲醛的实验研究

Experimental Study of Low Temperature Plasma and Catalyze Process on Formaldehyde Decomposition

为了消除甲醛对空气的污染,实验研究了低温等离子体与催化相结合的降解技术。气体放电产生的低温等离子体和紫外光为催化剂TiO2光催化作用提供激发能源,TiO2通过X射线衍射图与UV-vis表征,选定合适的TiO2后置负载于放电器的接地极板上。实验表明,在气体放电作用下甲醛降解迅速,降解率随它的初始质量浓度0ρ(CH2O)的变化有一峰值,0ρ(CH2O)过低和过高都不利于甲醛的去除;催化剂对甲醛降解有明显的促进作用,有TiO2薄膜时,甲醛去除率的峰值由73%提高到84%;电场强度是降解效率的主要决定因素,降解效率随着电场强度的增加而上升。

The low temperature plasma is combined with a catalytic method for decomposing the formaldehyde jointly to degrade the volatility organic compound. The low temperature plasma is produced by gas discharge. The type of the reactor is line-board, its material is stainless steel, and there are eight groups in the reactor. The low temperature plasma and the ultraviolet ray which is produced by gas discharge provide excitation energy for titanium dioxidephotocatalysis. The titanium dioxide is loaded on negative plate of the line-board gas discharge reactor after selected by token of XRD and UV-vis. The power supply is the 15 kV alternating current, and the voltage scope is controlled by a transformer. The experimental results show that the max corona voltage ascends along with the discharge distance. The rate of decomposition is rapid, and there is a peak value of the efficiency of decomposition. The relationship between initial concentration and residence time is important for the reactor design in application. The peak value of the efficiency of decomposition increases from 73% to 84%, when there is TiO2 film, this shows that the catalyst accelerates the degradation of the formaldehyde The electric field intensity is the predominate factor of the efficiency of decomposition. The plasma-catalysis is an effective technology for degradation of volatility organic compound.