Byproduct identification and mechanism determination in plasma chemical decomposition of trichloroethylene
Plasma chemical behavior of trichloroethylene (TCE) was investigated with a packed-bed ferroelectric pellet reactor and a pulsed corona reactor. Volatile byproducts were identified by gas chromatography and mass spectrometry (GC-MS), and it was shown that reactor type, TCE concentration, flow rate, background gas, and moisture affected TCE decomposition efficiency and product distribution. Byproduct distributions in nitrogen and the negative effect of oxygen and moisture on TCE decomposition efficiency show that TCE decomposition proceeds via initial elimination of chlorine and hydrogen atoms, the addition of which to TCE accelerates its decomposition. Active oxygen species like OH radical is less likely involved in the initial step of TCE decomposition in plasma. Triplet oxygen molecules (3O2) scavenge intermediate carbon radicals derived from TCE decomposition to give much lower yields of organic byproducts.