estudio y caracterización de un plasma de microondas a presión ...

2.3. Results
2.3.1. Destruction of trichloroethylene
Capítulo 2
The trichloroethylene destruction process was studied in a helium plasma under
variable conditions as regards applied microwave power, gas flow-rate, inner diameter of
the coupler tip and C2HCl3 concentration.
2.3.1.1. Influence of the applied microwave power
The principal mechanism for the decomposition of residual molecules in non-
equilibrium plasmas is via electron collisions. The efficiency of which increases when
the amount of energy released to free electrons in the plasma increases. As a result, the
electronic density and temperature of the plasma have a direct impact on the efficiency
with which contaminants can be destroyed since the microwave energy supplied to the
torch via the waveguide is used to reach optimum efficiency [19, 20]; therefore,
increasing the applied power increases the electron density and temperature of the
plasma, and the efficiency with which the compounds introduced in the main gas flow
are destroyed.
C 2 HCl 3 concentration (ppb)
60
55
50
45
40
35
30
25
20
15
10
5
0
Total flow rate: 1.0 L/min
C 2 HCl 3 : 1000 ppm
Helium
300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
Microwave Power (W)
Figure 2.2: Variation of the C 2HCl 3 concentration in the helium plasma as a function of the
applied microwave power.
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