José Muñoz

Hydrogen Production from Ethanol Decomposition by Two Microwave Atmospheric Pressure Plasma Sources: Surfatron and TIAGO Torch

Molecular hydrogen production from ethanol decomposition by two microwave atmospheric pressure plasma sources (surfatron and Torche a Injection Axiale sur Guide d’Onde (TIAGO) torch) was studied by optical emission spectroscopy and mass spectrometry. In both cases ethanol was almost completely decomposed, thus giving place to molecular hydrogen. However, the atmosphere surrounding the discharge significantly influences the overall decomposition process. When the surfatron is used, C2H2 and CO are obtained as exhaust gases. Likewise, H2O and HCN are also detected at plasma exit when sustained with the TIAGO torch.

Surface Wave Discharges Generated with Ar/He and Ar/N2 Gas Mixturesat Atmospheric Pressure

This work is aimed at studying emission spectra and morphological characteristics of surface wave discharges generated with Ar/He and Ar/N2 gas mixtures at atmospheric pressure with powers ranging from 80 to 400 W. In both cases, power density is higher than that found with pure Ar, although these changes are due to different discharge features. Kinetic processes can be derived from the analysis of plasma-emitted spectra. We also provide evidence of variations in the external aspect of discharges (filamentation and contraction) related to changes in thermal conductivity in gas mixture.

Hydrogen and By-Products Formation After the Decomposition of Ethanol by Means of a Microwave Plasma Torch at Atmospheric Pressure

Argon TIAGO torch plasma in air ambience has been studied to produce the decomposition of ethanol obtaining hydrogen at the plasma exit. Dependence of by-products formed on ethanol flows has been studied. Ethanol molecules were completely decomposed, and an important conversion to hydrogen was obtained. Images of plasma generated in these conditions are presented.

Atmospheric Pressure

This paper shows the morphological modifications of an atmospheric-pressure argon surface-wave discharge when small amounts of nitrogen are introduced into the plasma (changes in the discharge color, disappearance of radial contraction, and appearance of postdischarge).

\hbox{Ar}{-}\hbox{N}_{2}

Microwave-torch plasmas sustained in easy-to-ionize gases such as argon are strongly affected by the presence of nitrogen when emerging into ambient air. Examination of pictures of their flame as a function of distance from the torch tip provides information to the setting of operating conditions (gas flow and microwave power) such as to minimize contamination of the discharge by nitrogen.

Surface-Wave Discharge Morphology

The use of the van der Waals broadening of Ar atomic lines to determine the gas temperature in Ar‐He plasmas, taking into account both argon and helium atoms as perturbers, has been analyzed. The values of the gas temperature inferred from this broadening have been compared with those obtained from the spectra of the OH molecular species in the discharge.