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

Abstract

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).

Microwave Discharges in Liquid Hydrocarbons: Physical and Chemical Characterization

“…Another method of microwave plasma generation in liquids is the coaxial input of microwave energy into the liquid, in which the discharge is ignited at the end of the central conductor of coaxial line (Figure 2c). It is the most widespread method of microwave plasma generation in liquids (see, e.g., [14,15,28,[37][38][39][40][41][42][43][44][45]). Modeling of electrodynamics of quarter wavelength [30] and coaxial [44] antenna systems has shown that in the latter system the microwave field strength at the tip of antenna is much less sensitive to the antenna length.…”

“…The presented photographs reflect the non-stationary nature of microwave discharges in liquids. Gas products of microwave discharge in n-heptane are studied much better than in other hydrocarbons [43], and it is possible to compare these results with the results obtained in other conditions.…”

“…Table 1. Comparison of distributions of gas-phase products in pyrolysis of n-heptane [57,58,61,62] and microwave discharge in liquid n-heptane [43]. All values are given in wt.…”

“…% (all data were recalculated on the basis of data from the original articles). In microwave discharge [43], among the products, acetylene and its homologs, as well as allene, absent in low-temperature experiments [57,59,61,62], were determined. The same products were fixed at temperatures of more than 800 • C in flow reactors [58,60] and in the shock tube [41,42].…”

“…Comparison of the results of chemical analysis of products obtained in a microwave discharge [43] in liquid n-heptane and barrier discharge [66][67][68] showed that the composition of products obtained in microwave discharge is much richer.…”