ISSN:
1572-8986
Keywords:
dichlorodifluoromethane (CCl2F2)
;
plasma system
;
radiofrequency
;
reaction mechanism
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Technology
Notes:
Abstract Decomposition of dichlorodifluoromethane (CCl2F2 or CFC-12) in aradiofrequency (RF) plasma system is demonstrated. The CCl2F2decomposition fractions ηCCl 2 F 2 and mole fractionsof detected products in the effluent gas stream of CCl2F2/O2/Ar andCCl2F2/H2/Ar plasma, respectively, have been determined. The experimentalparameters including input power wattage, O2/CCl2F2 or H2/CCl2F2 ratio,operational pressure, and CCl2F2 feeding concentration wereinvestigated. The main carbonaceous product in the CCl2F2/O2/Arplasma system was CO2, while that in the CCl2F2/H2/Ar plasma systemwas CH4 and C2H2. Furthermore, the possible reaction pathways werebuilt-up and elucidated in this study. The results of the experimentsshowed that the highly electronegative chlorine and fluorine wouldeasily separate from the CCl2F2 molecule and combine with the addedreaction gas. This led to the reactions terminated with the CO2,CH4, and C2H2 formation, because of their high bonding strength. Theaddition of hydrogen would form a preferential pathway for the HCland HF formations, which were thermodynamically stable diatomicspecies that would limit the production of CCl3F, CClF3, CF4, andCCl4. In addition, the HCl and HF could be removed by neutral orscrubber method. Hence, a hydrogen-based RF plasma system provideda better alternative to decompose CCl2F2.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1007027805680
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