Generally, flames already contain a weakly ionized plasma
with typical density greater than 1010 ions/cm3. For example,
the oxidation of methanol by oxygen atoms is ten million times
faster than that by oxygen molecules at the gas temperature of
1300 K [6]. If so, as mentioned earlier, because the microwave
plasma torch has high plasma density of ∼1013/cm3 in air
discharge and high temperature of 6000 K at the center axis
[7], we expect that the microwave plasma torch can accomplish
mostly perfect combustion of fuel.