Effects of Superheated Steam or Nitrogen as a Diluent on the Production of Tetrafluoroethylene by Pyrolysis of Chlorodifluoromethane

Abstract

Influences of a diluent (steam or nitrogen) on the tetrafluoroethylene (TFE) preparation by pyrolysis of chlorodifluoromethane (R 22) have been studied. The reaction was carried out under atmospheric pressure by a flow method in the adiabatic tank reactors at the temperature ranging from 640 to 850° C, the residence time being less than 1 s. The molar ratio of a diluent to R 22 was varied from 0.2 to 9.0.
The conversion of R 22 increased with an increase in the amount of the diluents (Fig.5). In the presence of steam, the conversion was not affected by space velocity of total gases, but by space velocity of R 22 (Figs.6 and 9).
The selectivity for the yield of TFE was dominated by space velocity of total gases and was independent of the diluents and their concentrations (Fig.7).