• Bulletin of the Korean Chemical Society
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• v.12 no.6
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• pp.652-658
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• 1991

The effect of intermolecular collisions in the infrared multiphoton dissociation (IRMPD) of difluorochloromethane was investigated using He, Ar, and $N_2$ as buffer gases. The reaction probability for IRMPD of difluorochloromethane was measured as a function of laser fluence and the buffer gas pressure under unfocused beam geometry. It was observed that the reaction probability was initially enhanced with the increase of buffer gas pressure up to about 20 torr, but showed a decline at higher pressures. The reaction probability increases monotonically with the laser fluence, but the rate of increase diminishes at higher fluences. An attempt was made to simulate the experimental results by the method of energy grained master equation (EGME). From the parameters that fit the experimental data, the average energy loss per collision, $<{\Delta}E>_d$, was estimated for the He, Ar, and $N_2$ buffer gases.

• Applied Chemistry for Engineering
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• v.10 no.2
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• pp.190-195
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• 1999

The thermal pyrolysis of chlorodifluoromethane (R22) for producting tetrafluoroethylene (TFE) has been studied using the tubular reactor designed by the authors. The reaction temperature over $600{\sim}850^{\circ}C$, residence time over 0.005~0.6 sec, and steam/R22 ratio 3 to 30 were varied through experiments to analyze the effect of these variables on the conversion of R22 and selectivity for TFE. We have provided the guidelines for the optimal operation and design for the pyrolysis reactor. With increasing the dilution ratio, not only the conversion of R22 but also the selectivity for TFE increase. The optimum range of reaction temperature was $700{\sim}750^{\circ}C$ and the residence time 0.07~0.1 sec. In the kinetic study, first order rate equation was fitted well with the experimental data. This indicates that the main reaction step is a $CF_2$ generation from R22 pyrolysis. The range of activation energy for the rate constant was obtained 44.7~48 kcal/mol.