Abstract

Hydrochlorofluorocarbons (HCFCs) are greenhouse gases and can deplete the ozone layer. To stop further adverse effects, the Montreal Protocol requires HCFCs to be collected and destroyed by 2020 for developed countries and 2030 for developing countries. We studied the decomposition reactions of CD3CD2CHFCl as a model system to emulate HCFCs currently in use to better understand how they would react when subjected to high temperature in a destruction chamber. The unimolecular reactions of energized CD3CD2CHFCl molecule are 1,1-HCl, 1,1-HF, 1,2-DCl and 1,2-DF elimination with a ratio of 0.16: 0.004: 0.82: 0.013. All elimination pathways form cis- and trans-alkenes and the ratio varied from 1 to 3.5. The data collected shows that the 1,1-HX (X=Cl, F) elimination reaction, forming a carbene, can become the dominant degradation pathway at high temperatures. After all results have been collected, they are calibrated to account for the fact that different molecules fragment differently. Calibrations using the stabilized product were done via proxy because some pure samples could not be acquired. Calibration factors are multiplied into the data and ranged from 1.71 to 8.38. By studying these degradation pathways, it can better understood how to destroy them or convert them into feedstock for other industries after they are all banned.

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