Reações de fotooxidação da amonia por LASER pulsado de gas carbonico e por descargas eletricas : aplicação a separação isotopica do deuterio da amonia natural

AUTOR(ES)
DATA DE PUBLICAÇÃO

1979

RESUMO

LASER photochemical reactions initiated by the multiphoton processs, were studied for various rrolecular systems. These studies indicated that the multiphoton excitation presents advantage af high selectivity and reactian yields. In our work we examined, the multiphoton excitation of Ammonia, in mixtures containing this gas and oxigen, using a pulse CO2 LASER which operates in the infrared region of 900 to 1100cm. The same mixtures were also subjected to the low and high power eletric discharges. The result is of the reactions obtained for the LASER and eletric discharges were compared. This comparision led us to suggest a dissociation mecanism for ammonia, which is the result of a multiphotonic absorption process accompanied by a collisional mechanism, justifies the dissociation in condition of the low LASER power density and relative high pressure in the gás mixture. The observed chain reaction was accompainied by a yellow flash permite us some considerations of the reaction mechanism for the NH2 X B1 and NH2 Ã A1 radicals with oxigen. The LASER excitation was carried out using three distinct frequencies of P(32); R(10) and P(16) lines, which are respectivelly in resonance, quasi resonance and out of resonance with the absorptions of the Ammonia molecule. The obtained reactions for the three case allowed us to evaluate the band broadening produced by the power density of radiation, originating a loss in the selectivity of excitation. Finally we studied the possible use of a LASER excitation to the isotop separation of Deuterium, in the NH2D present in natural Ammonia. These results showed that the LASER Separation of Deuterium is feasible.

ASSUNTO(S)

fotoquimica lasers em quimica amonia - oxidantes fotoquimicos

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