A method for determining the relative reactivity of volatile organic compounds (VOCs) with respect to the air plasma of a pulsed corona discharge is proposed. It is based on the use of specially selected mixtures of organic compounds. The approach is based on the method of competing reactions: all components of the mixture are in equal conditions, so the relative reactivity can be determined with high accuracy using the gas chromatography. The parameters of scaling processes are proposed – plasma chemical yield, relative reactivity, formal reagent as a set of plasma components. In this paper, using the example of a number of VOCs, we demonstrate the extended capabilities of the method using a special technique for processing experimental data. More accurate data on the relative reactivity of a number of VOCs of wide application have been obtained. It is proposed to use the energy yield of ozone as a criterion for the energy efficiency of a plasma chemical installation.

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Обнаружено каталитическое влияние электроотрицательных добавок (ССl4 и фреона-113) на процессы конверсии летучих органических соединений под действием неравновесной плазмы атмосферного давления, генерируемой импульсным коронным разрядом. Показано, что данные добавки в концентрации менее 0.1% значительно уменьшают ток разряда, но при этом энергетическая эффективность процесса удаления летучих органических соединений возрастает. На примере удаления паров перхлорэтилена (ПХЭ, C2Cl4) количественно продемонстрировано каталитическое влияние электроотрицательных добавок на процесс конверсии в воздухе и азоте. Так, добавка 0.085% CCl4 в воздух позволяет снизить энергозатраты при удалении ПХЭ с концентрацией 0.09% в 2 раза (с 12 до 6 eV / molecule при степени очистки 63%). Предложены механизмы активного влияния электроотрицательных добавок на ток разряда и на процессы удаления примесей. DOI: 10.21883/PJTF.2017.24.45348.16857

Investigations of methane conversion in atmospheric-pressure mixtures of various composition and temperature, irradiated by pulsed nanosecond electron beams and non-self-sustained discharges initiated by electron beams, were carried out. It was shown that during direct conversion at room temperature, the energy cost of the conversion of one CH 4 molecule (5.6 eV molecule −1 ) was commensurate with that obtained in the experiments with the use of continuous electron beam. The main products of direct conversion were hydrogen and ethylene. If a small amount of oxygen was present in the mixture, methanol was added to the conversion products, which in turn decomposed into CO, CO 2 and H 2 O. The results of numerical simulations and experiments were basically the same. The use of a non-self-sustained discharge increased the degree of direct conversion of methane, but the energy cost of conversion also increased. The main products of carbon dioxide conversion of CH 4 (dry reforming) under the action of pulsed electron beam at room temperature were CO, H 2 , C 2 H 6 , and carbon. Energy cost of conversion (12 eV molecule −1 ) was about two times higher than in the case of direct conversion of methane. However, the use of pulsed electron beam for dry reforming turned out to be energetically more efficient than the use of the most types of discharges. The main products of CH 4 oxidative conversion by pulsed electron beam were H 2 , C 2 H 6 , and C 2 H 4 . At room temperature, the energy cost of methane conversion without a catalyst was 9 eV molecule −1 , whereas the use of Ni catalyst resulted in a seven-fold increase, and the use of NaOH/CaO one-in a 14-fold increase in the conversion efficiency compared to irradiation without a catalyst. When the temperature of the catalysts rised to 623 K, the conversion efficiency increased by another four times. The processes in electron-beam plasma that provide the implementation of the main mechanisms of methane conversion are also discussed in the paper.