Cooperative Research on Gaseous Air Contaminants Removal by using of Discharge Plasma Processing

本项目的主要目的是利用非热等离子体处理技术对气态空气污染物进行净化的基础研究和实用技术开发。研究的污染物是各种挥发性有机化合物（VOCs）和NOx从燃料燃烧排出的烟气。典型的挥发性有机化合物是氯氟烃（CFC-113：控制防止臭氧层破坏）、卤代有机化合物（三氯乙烯、四氯化碳：引起癌症或其他）和正常有机材料如酒精、丙酮。非热等离子体是通过各种方法产生的。它们是使用具有在内壁上形成的条形电极的氧化铝陶瓷反应器或具有在内壁上接触的螺旋线电极的石英管的高频表面放电、阻挡放电或其中阻挡不是必需的超短脉冲放电。并对这些放电的组合效应或相互比较进行了检验。在任何情况下，如果提供足够的放电能量，则可以获得大于95%的非常高的分解率。VOCs分解的最终产物是二氧化碳和水。采用FID-GC、GC-MS和FTIR等方法对等离子体分解NOx的各种副产物进行了表征，发现等离子体分解NOx的过程强烈依赖于残余氧浓度。添加氨或其他物质对增强NOx去除是必要的。催化、添加剂和等离子体处理相结合的方法对降低NOx是非常有效的。

The main aim of this project is that fundamental research and development of practical technology of cleaning gaseous air contaminants by using Non-Thermal Plasma Processing. Contaminants studied are various volatile organic compounds (VOCs) and NOx in flue gas exhausted from fuel combustion. Typical VOCs are chlorofluoro-carbon (CFC-113 : controlled against ozone layr depletion), halogenated organic compounds (trichloroethylene, tetrachloromethane : cause of cansor or others) and normal organic materials such as alcohol, acetone. Non-Thermal Plasma is generated by various methods. They are high frequency surface discharge using an alumina ceramic reactor with stripe electrode formed on inner wall or a quartz tube with a spiral wire electrode contacted on the inner wall, barrier discharge, or ultra short pulse discharge where barrier is not essential. Combining effects of those discharge or mutual comparison were also tested now. In any case, very high decomposition rate more than 95% is available, if enough dischage energy is supplied. Final products of VOCs decomposition are found to carbondioxide and water. Various byproducts generated by the plasma were identified by using FID-GC,GC-MS and FTIR.It is found that NOx decomposition by the plasma is strongly dependent on the residual oxygen concentration. The addition of anmonia or others is necessary to enhance NOx removal. Combined method of catalysis, additioning and plasma processing was very effective in reducing NOx.