The Formation of Gas Bubbles by Processing of Liquid n-Heptane in the Microwave Discharge

et al. 2019

Emission spectra and gas products of microwave discharge in liquid n‐heptane with and without argon bubbling (6–40 l h−1) are investigated. The discharge was excited in a system with a coaxial input of energy. The pressure above the surface of the liquid was equal to atmospheric pressure. It is shown that the addition of argon changes the spectral composition of the plasma radiation, in which the emission of hydrogen and argon atomic lines appears. The addition of argon does not affect the rotational and vibrational temperatures of the state C2true(d3normalΠgtrue), the composition and the ratio of the main gas products (H2, CH4, C2H2, C2H4).

Section: Resultsmentioning

confidence: 60%

Microwave discharge in liquid n‐heptane with and without bubble flow of argon

Averin

Билера

et al. 2019

“…In 2D simulation of the MW discharge in liquid n ‐heptane, the electron concentration in the discharge was estimated to be about 10 14 cm −3 . The role of electron impact in the decomposition of hydrocarbon can be important at the initial stage of discharge evolution.…”

Section: Resultsmentioning

confidence: 99%

“…In 2D simulation of the MW discharge in liquid n-heptane, the electron concentration in the discharge was estimated to be about 10 14 cm −3 . [29,30] The role of electron impact in the decomposition of hydrocarbon can be important at the initial stage of discharge evolution. As the temperature increases, the role of thermal dissociation grows and just the latter mechanism determines decomposition of hydrocarbons.…”

Section: Resultsmentioning

confidence: 99%

“…[22][23][24] The results of 1D and 2D simulation of electromagnetic fields and the processes characteristic for inliquid plasmas have been reported. [25][26][27][28][29][30] It is known that processing of liquid hydrocarbons by MW discharge of any type leads to formation of nanosize carbon-containing particles. However, to our best knowledge, there is no publications devoted to systematic characterization of the solid-state products obtainable by MW plasma for a wide range of hydrocarbon liquids.…”

Section: Introductionmentioning

confidence: 99%

“…Investigations of in‐liquid MW plasma with the aid of emission spectroscopy in the visible range have been published . The results of 1D and 2D simulation of electromagnetic fields and the processes characteristic for in‐liquid plasmas have been reported …”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Nanosize carbon products formed in microwave discharge in liquid alkanes

Averin

Щеголихин

et al. 2017

Carbon‐containing nanosize solid‐state phase have been produced in the atmospheric pressure microwave (MW) plasma ignited in the gas bubbles in liquid alkanes CnH2n+2 (n = 7, 8, 10, 15, 16). Gas bubbles are generated by flow of argon. According to SEM data, the solid‐state products are represented by particles having dimensions in the range of 100–200 nm. Raman spectra of the sooty‐like unpurified solid products permit to categorize them as sp3+sp2 mixed forms of carbon comprising mainly an “damaged grapheme” along with a “few‐layer” graphite nanoparticles. NMR spectra of the solid products show strong aromatization and formation of various unsaturated molecular fragments. FTIR‐ATR spectra indicate that the carbonaceous nanoparticles are contaminated with minor amounts of different hydrocarbon residues and oxidized species.

Light emission from microwave discharges in liquid hydrocarbons at the initial stages of their development

Krashevskaya

Batukaev

et al. 2021

Time‐resolved optical techniques (spectrograph, high‐speed camera, photodiode) were used for scrutinizing the initial stages of the microwave discharge (2.45 GHz, 200–500 W) achieved in liquid alkanes (CnH2n + 2). Petroleum solvent Nefras S2 80/120 (a mixture of light hydrocarbons with boiling temperatures ranging between 33°C and 205°C) was considered to be representative of alkanes. The discharge was ignited in the liquid, at the end of a molybdenum antenna located under ambient conditions above the liquid. The discharge displaced sequences of light pulses of different shapes and amplitudes, randomly distributed in time. The minimum pulse duration is 0.5 ms. At times close to 1 ms, the spectrum comprises emission bands of the C2 molecule, lines of hydrogen, and the C+ ion, but there is no continuum associated with the emission of the formed solid carbon‐containing particles. In a number of cases, an anomalous spectrum of the C2 molecule was recorded, with no such sequences having been observed before.