PHLEGMATIZATION OF METHYL CHLORIDE AND CHLORINE GAS MIXTURES BY CARBON TETRACHLORIDE IN THEIR PHOTOIGNITION

Subject of investigation (scientific study) — the photoignition of CH3Cl + Cl2 gas mixtures in the presence of carbon tetrachloride. The inflammation was initiated by radiation of mercury-quartz lamp of 1 kW. The experimentally determined value of the minimum phlegmatization concentration (MPC) CCl4 was 33 % (vol.). The calculation of the MPC was based on the heat balance equation, in which the limiting (peak) adiabatic combustion temperature is the combustion temperature in the lower concentration limit of photoignition in the conditions of the first two fastest stages of the sequential substitution of hydrogen atoms by chlorine. The calculation was performed for an equimolar mixture of CH3Cl + Cl2. The resulting calculated value was 35.9 % (vol.), which is in good agreement with the experimental value. It is concluded that for the evaluation of the phlegmatization action of neutral (not participating in the chemical transformation) substances, the heat balance equation can be used. Based on this method the estimates of phlegmatizing concentration of hydrogen chloride are provided.