OH kinetics in photo-triggered discharges used for VOCs conversion

The kinetic of the hydroxyl radical is studied in N2/O2/H2O mixtures with small amounts of acetone or isopropyl alcohol (0.5%). The radical density is measured in absolute value in the afterglow of a photo-triggered discharge, which generates an homogeneous transient non-equilibrium plasma, using a time resolved absorption measurement method. For dry mixtures, experimental results are compared to predictions of a self-consistent 0D discharge and kinetic model. It is shown that dissociation of the VOCs through quenching collisions of nitrogen metastable states plays an important role in the production of OH. Measurements can not be explained looking only at the oxidation of acetone or IPA by the oxygen atom. This result is reinforced by experimental results about the OH density in wet mixtures, with or without VOCs, compared to dry ones

Microwave micro-plasmas in air: simulations and experiment

International audienc

Microwave air plasmas in capillaries at low pressure II. Experimental investigation

International audienc

Hydrodynamic study of a microwave plasma torch

A hydrodynamic model was developed to simulate the flow and the heat transfer with the gas/plasma system produced by a microwave-driven (500–900 W at 2.45 GHz) axial injection torch, running in atmospheric pressure helium at 3–9 L min−1 input gas flows. The model solves the Navier-Stokes’ equations, including the effect of the plasma upon the momentum and the energy balance, in order to obtain the spatial distributions of the gas velocity and temperature. The model predicts average gas temperatures of 2500–3500 K, in the same range of those obtained by optical measurements. Simulations show that the plasma influences the gas flow path and temperature, promoting an efficient power transfer

Numerical and experimental analysis of microwave micro-plasmas in air

International audienc

Study of microwave micro-plasmas in air

International audienc