Hexafluoropropane Thermal Decomposition Performance Of Nano-metal Oxide

To improve fire extinguishing performance of HFCs extinguishing and give reference to the research on its extinguishing fire in cooperation, an experiment research system with functions that supplying raw material according to requirements, programmed temperature and gas chromatography was designed on the basis of former research. The products of thermal decomposition of HFC-236fa at different temperatures and residence times were analyzed through using gas chromatography (GC), gas chromatography/mass spectrometry (GC/MS), Fourier transform infrared spectrum (FTIR), fluoride ion-selective electrode (FISE) and ion chromatography. The changes of products and process in the thermal decomposition after adding to Nano-MgO and Nano-CeO2 were specially investigated. The changes of the composition of Nano-MgO were studied by using X-ray diffraction and FTIR for further research. The reasons of the changes in the thermal decomposition were studied seriously. The conclusions were summarized as following:(1)HFC-236fa was steady at 500 degree. It started to decompose at 600 degree and has the intense decomposition at 700 or 800 degree. Fluoride elimination was the most feasible reaction in thermal decomposition of HFC-236fa.The decomposition of HFC-236fa became stronger with the increase of the temperatures and the enhancement of residence times.(2)The decomposition of HFC-236fa became stronger after adding to Nano-MgO. This illustrated that Nano-MgO make the thermal decomposition stronger. MgF2 was found on the Nano-MgO after reaction and the concentration of the MgF2 increased with the increase of the temperatures, it made that the concentration of the HF produced from the decomposition was obviously decreased.(3)The decomposition of HFC-236fa became stronger after adding to Nano-CeO2, the decomposition rate was lower than that adding to Nano-MgO, but the products were more. F3C—CF(CF3)—CF2—CF3 was first found. CeF3 was found on the Nano-CeO2, its size was larger and more perfect as the increase of the temperature.