Decomposition of tetrafluoromethane by water plasma generated under atmospheric pressure

Tetrafluoromethane (CF4) decomposition by water plasma generated under atmospheric pressure was investigated by means of thermodynamic analyses and experiments. Thermodynamic equilibrium calculations were performed between 300 and 6000 K at atmospheric pressure. Experimental results indicated that CF4 was completely decomposed by water plasma, and recovery of fluorine can be achieved more than 99%. Influence of factors such as arc current and additive flow rate of O2 on CF4 decomposition was determined. Furthermore, the decomposition mechanism of CF4 was investigated from chemical kinetics consideration. CFx (x: 1–4) was thermally decomposed above 4000 K, oxidized in the temperature range of 4000–2400 K, and removed by H radical at temperatures below 2400 K.