Gas-phase reaction of CHF₃ (HFC 23) with CH₄ in the presence of CBrF₃ (halon 1301) to produce CH₂=CF₂ (VDF) is presented. Experiments were carried out in a plug-flow reactor at temperatures between 873 and 1173 K. Under these conditions, CH₂=CF₂ was a dominant product observed, with CH₂F₂, C₂H₂, CH₂CHF, C₂F₄, C₂H₆ and CHFCF₂ also detected. In the presence of less than 6000 ppm of CBrF₃, the rate of formation of CH₂=CF₂ is significantly enhanced, and a much lower rate of formation of the major by-product, C₂F₄ is observed. Further increasing the proportion of CBrF₃ in the feed resulted in an even higher rate of formation of CH₂=CF₂. Experimental results are fitted very well by a model derived from the NIST and GRI-Mech 3.0 mechanisms, modified to include additional published kinetic data.
Journal of Hazardous Materials Vol. 180, Issue 1-3, p. 181-187