Preparation of a gas (mixture) containing fluorine molecule, comprises decomposing nitrogen trifluoride by passing high density hot electron plasma at atmospheric pressure, to obtain high temperature, cooling and rapid cooling

摘要

Preparation of a gas or a gas mixture containing molecular fluorine from a gas or a gas mixture of fluorine derivative, comprises decomposing fluorine gas (mixture), particularly nitrogen trifluoride by passing a high density hot electron plasma at atmospheric pressure or a pressure close to it, to obtain a maximum temperature (T max) higher than 2000 K of the heavy species in plasma, cooling the mixture of the various species in plasma to a temperature (T h) followed by rapid cooling to obtain a gas mixture containing of fluorine in molecular form. Preparation of a gas or a gas mixture (I) containing molecular fluorine from a gas or a gas mixture (II) of fluorine derivative, comprises decomposing (II), particularly nitrogen trifluoride by passing a high density hot electron plasma at atmospheric pressure or a pressure close to the atmospheric pressure to obtain a maximum temperature T max higher than 2000 K of the heavy species in plasma, cooling the mixture of the various species in plasma to a temperature T h, then rapid cooling between T h and T b (where T h and T b are two temperatures determined in experiments according to gas or the gas mixture containing fluorine, T h is the temperature from which the gas molecules or mixture of gases initially injected into plasma can start to be reformed from their dissociation fragments and T b is the temperature to which more than 90% of the fluorine atoms resulting from dissociation in plasma recombined) to obtain (I). An independent claim is included for a fluorinated gas generator delivering (I), comprising a source of nitrogen trifluoride in gaseous form, generators of a high density hot electron plasma to decompose the fluorinated gas molecules and to generate a plasma at a maximum temperature of the heavy, neutral and ionic species T max higher than 2000 K, cooling unit for the gas mixture resulting from the decomposition and recovery unit of the gas mixture containing fluorine molecules cooled at temperature lower than T b.