A Study on the Ethylene Dichloride Decomposition by Using a RF Plasma System

• Main Authors: Yang Renbo, 楊仁泊
• Other Authors: Li Chun-Teh, Lee Wen-Jhy
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/37233041392160286144

碩士 === 國立成功大學 === 環境工程研究所 === 83 === In this study ethylene dichloride was decomposed in a radio frequency plasma system. The degradation products were analyzed by using a Fourier infrared spectrophotometer (FTIR). The results show that when argon plus oxygene was used the carrier gas, a better degradation was obtained. At low gas pressures, plasma was more easily generated, less power was needed to achieve the same degradation results, and the plasma temperature was lower. The main gaseous products from degradation in plasma were CO2, CO, H2O, and HCl. The main product from oxygenless plasma was C2H3Cl. Other organo- chlorine products found were CCl4, C2HCl3, while non- organochlorine products were mainly two- carbon hydrocarbons, such as C2H2, C2H4, and C2H6. Among the four internal electrodes plated with four different metals (gold, copper, nickle, and chromium), the copper-plated electrode was found to have the best result. In all cases, depo- sition was found inside the reactor, causing a gradual decrease in the degradation efficiency curve. An extreme Φ value of the external electrode would cause deposition inside the wall. This deposition may be removed with an oxygen plasma. When the gas flow rate was 25 sccm, concen- tration was 6%, pressure was 9 torr,Φ value was between 1.0 ~ 1.3, and the input power was 50 watt, the degration efficiency and conversion rate (CO2+CO) were found to be higher than 99.99% and 95%, respectively. In addition, under the same condition, both the degradation efficiency and conversion rate at the external electrode were higher than those at the internal. In the competion between ethylene dichloride (EDC) and dichloro- methane ( DCM), the degradation of the former was found to be easier.