Naphthalene and Acenaphthene Decomposition by Electron Beam Generated Plasma Application

Abstract

The application of non-thermal plasma generated by electron beam (EB) was investigated in laboratory scale to study decomposition of polycyclic aromatic hydrocarbons like naphthalene and acenaphthene in flue gas. PAH compounds were treated by EB with the dose up to 8 kGy in dry and humid base gas mixtures. Experimentally established G-values gained 1.66 and 3.72 mol/100 eV for NL and AC at the dose of 1 kGy. NL and AC removal was observed in dry base gas mixtures showing that the reaction with OH radical is not exclusive pathway to initialize PAH decomposition, however in the presence of water remarkably higher decomposition efficiency was observed. As by-products of NL decomposition were identified compounds containing one aromatic ring and oxygen atoms besides CO and CO 2 . It led to the conclusion that PAH decomposition process in humid flue gas can be regarded as multi-step oxidative de-aromatization analogical to its atmospheric chemistry.

Kinetic Mechanisms of Electron-Beam Induced Polycyclic Aromatic Hydrocarbons Transformation in Flue Gases

“…The concentration of OH-radical behaves as non-monotonous function of the dose lowering down to 1.6 ppb on the interval D = 1-4 kGy and then increasing up to 4 ppb at D = 20 kGy. The model predictions of NL decomposition, the simplest representative of the PAHs compounds, and their comparison with experimental data [8] are given in Fig. 5 for two gas mixtures: N 2 /O 2 /H 2 O (84/10/6, vol.%) and N 2 /O 2 (90/10, vol.%).…”

“…The leading role of OH radicals in the degradation of aromatic molecules is due to both Fig. 6 Products of NL decomposition under EB irradiation in wet gas mixture: 1-naphthalene, 2-nitronaphthalene, 3-products of nitronaphthalene decomposition, 4-2-formyl-cinnaldehyde, 5-naphthol; lines are the model predictions, points are the experimental data [8] Plasma Chem Plasma Process their higher concentration in the irradiated gas and quite a high value of their reaction rate constant.…”

“…As experimental data show, the interaction of aromatic molecules with active components induced by EB treatment of flue gases results in their decomposition [7][8][9]. On the other hand, at some process conditions it is observed the formation of higher-ringed compounds, which may be more toxic than initial ones [10].…”

Organic Pollutants Treatment from Air Using Electron Beam Generated Nonthermal Plasma – Overview

“…These results demonstrated the insignificant role of adsorption for PAHs removal (Callén et al, 2007). Naphthalene (NL) and acenaphthene (AC) decomposition in gas mixture was studied in lab scale experiment (Ostapczuk, et al, 2008b). It was found that NL was more easily decomposed than AC, G-values for these two compounds were 1.66 and 3.72 mol/100 eV for NL and AC at the dose of 1 kGy , respectively.…”

Atmospheric pressure dielectric barrier discharge for the remediation of soil contaminated by organic pollutants

“…Non-thermal plasmas (NTPs) are regarded as promising advanced oxidation processes (AOPs) for the sustainable and efficient removal of organic pollutants from wastewater (Ognier et al 2009;Hijosa-Valsero et al 2013;Iya-Sou et al 2013;Jamróz et al 2014;Magureanu et al 2015;Stratton et al 2015) and polluted gas (Ostapczuk et al 2008;Malik et al 2011;Jolibois et al 2012;Bao et al 2014;Zhang et al 2015). During the last few years, they have started to be examined for soil remediation (Wang et al 2010;Lou et al 2012;Ognier et al 2014;Aggelopoulos et al 2015a).…”