Thermal Plasma Decomposition of Tetrachloroethylene

Abstract

Tetrachloroethylene (C 2 Cl 4) has been used widely as a solvent and dry cleaning agent, but was later specified as possible human carcinogen. As a result, its safe treatment became a priority. In this paper, we report on its decomposition in an atmospheric radiofrequency thermal plasma reactor. Main components of the exhaust gases were determined by Fourier transform infrared spectroscopy. We found that complete decomposition can be achieved in either oxidative or reductive conditions but not in neutral one. The solid soot product was characterised by transmission electron microscopy and specific surface area measurement. Organic compounds adsorbed on the surface of the soot were extracted by toluene and comprised, based on gas chromatography mass spectrometry, of various perchlorinated aliphatic (for example hexachlorocyclopentadiene) and aromatic compounds (like hexachlorobenzene, octachloronaphthalene or octachloroacenaphthylene). Several nitrogen containing molecules were also identified whose presence are rare during thermal plasma treatments. Further investigation of the extract by mass spectrometry revealed various higher molar mass chlorinated carbon clusters and two types of fullerenes (C 60 and C 70). Run-15 20 800 O 2 1 4 Run-16 20 260 O 2 1 1.2 Run-17 20 400 O 2 10 20 Run-2 40 Run-3 13 Run-4 31 Run-5 17 Run-7 24 Run-13

In-flight Synthesis of Nanosized ZrC Particles from Various Precursors in RF Thermal Plasma

“…The torch was mounted vertically on top of the reactor connected simultaneously to a cyclone and a vacuum pump. A detailed description of the system and schematic presentation is illustrated in our previous publications [34][35][36]. Zirconium(IV)-propoxide solution (NZP: Zr(OCH 2 CH 2 CH 3 ) 4 70 wt% in 1-propanol, from Sigma-Aldrich) was applied as the zirconium and carbon source, the liquid was delivered by a peristaltic pump (Masterflex) to the atomizer probe placed in the center of plasma flame.…”