SEKIGUCHI Hidetoshi Tokyo Institute of Technology, Dept. Chem. Eng., Research Associate, 工学部, 助手 (50226643)
WATANABE Takayuki Tokyo Institute of Technology, Dept. Chem. Eng., Research Associate, 工学部, 助手 (40191770)
HONDA Takuya Tokyo Institute of Technology, Dept. Chem. Eng., Associate Professor, 工学部, 助教授 (10016595)
|Budget Amount *help
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1991: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1990: ¥1,500,000 (Direct Cost: ¥1,500,000)
The decomposition of CCl_2F_2 was studied using a thermal argon plasma. Thermodynamic calculations were performed to obtain the informations about the products. In the calculations, 73 species were considered in the four kinds of the reaction systems : C-Cl-F-Ar, C-Cl-F-H-Ar, C-Cl-F-O-Ar, and C-Cl-F-H-O-Ar which respectively corresponded to CCl_2F_2 decomposition without gas addition, with H_2, with O_2, and with H_2 and O_2 or H_2O. The results indicated that the simultaneous addition of H_2 and O_2 was effective for the decomposition of CCl_2F_2 since HF, HCL, and CO_2 or CO were dominant in C-Cl-F-H-O-Ar reaction system.
The numerical calculations were also performed in C-Cl-F-H-O-Ar reaction system with the assumptions of one dimensional flow, 26 species, and 60 step reactions. The results showed as follows : CCl_2F_2 was decomposed rapidly. When the reaction gases of CCl_2F_2, H_2, and O_2 were fed in the ratios 1 : 2 : 1, the product gases consisted of CO, CO_2, H_2, HF, HCl, and Cl_2, which was similar to the results of the water addition. An excess of H_2 suppressed the formation of Cl_2. While CO, HF, and HCL were produced when the ratio of CCl_2F_2 : H_2 : O_2 was 1 : 2 : 0.5.
The experimental studies were carried out using Ar plasma jet generated by d. c. arc discharge at atmospheric pressure. The experimental results showed that CCl_2F_2 was completely decomposed and converted to CO and CO_2 with the addition of H_2 and O_2. However the conversions about the components of Cl and F were not investigated, thus the further analyses must be carried out.
These results mentioned above confirmed that the thermal plasma methods was useful to decompose CCl_2F_2 rapidly and abundantly.