Influence of gas atmosphere on synergistic control of mercury and dioxin by non-thermal plasma

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Aiming at mercury and dioxin in fire coal gas as research objects, NTP (Non-thermal plasma，NTP) catalytic technology was used to investigate the degradation effect of operating condition parameters on mixed pollutants in mixed flue gas condition, and to explore the synergistic degradation of Hg0 and TCB (1,2,3-Trichlorobenzene, TCB) under mixed flue gas conditions. The research results showed that the conversion efficiency of mercury and TCB increased with the addition output of voltage, and decreased with the increase of the gas flow rate. Under optimal reaction conditions: voltage=17kV, frequency=300Hz, gas flow rate=2L/min, the conversion efficiency of Hg0 and TCB reached the highest 91.4% and 84.98%, respectively. In the NTP catalytic system, active free radicals played an important role in the synergistic conversion of mercury and TCB, which have a competitive effect, to make the conversion efficiency of mixed pollutants lower than a single substance. In the mixed flue gas condition, the mixed gas has an inhibitory effect on the synergistic conversion of mercury and TCB. Kinetic modeling of NTP catalytic synergistic reaction was established. Under three conditions of TCB, mercury and TCB, mixed simulated flue gas, the NTP catalytic technology showed a quasi-first-order kinetic reaction for the degradation of TCB. According to the synergistic effect of NTP and composites, the transformation and degradation of TCB mainly included two processes: TCB and ring opening, and Hg0 was finally oxidized to Hg2+.

Section: Effect Of Discharge Frequency On the Conversionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Research on degradation mechanism of trichlorobenzene and Hg⁰ by nonthermal plasma catalysis

Bian¹,

Zhu

Zhu³

et al. 2023

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“…In the dechlorination process of TCB, the dissociation energy of the C-Cl bond on the benzene ring in TCB is Cl (2)<Cl (1)<Cl (4), in which the Cl(2)-C bond is relatively unstable. The presence of 1,4dichlorobenzene suggests the dechlorination process of the TCB decomposition [32][33][34][35][36]. The possible decomposition pathway of TCB by NTP is shown in figure 10, which is inferred from the by-products of TCB.…”

Section: Influence Of the Oxygen Content On The Tcb Removal Efficiencymentioning

confidence: 99%

1,2,4-trichlorobenzene decomposition using non-thermal plasma technology

Zhu¹,

Zhang²,

Ma³

2020

Non-thermal plasma (NTP) is regarded as a potential application for environmental pollution control due to its ability to remove pollutants. As a major precursor of dioxins, the influence of the parameters of 1,2,4-trichlorobenzene (TCB) decomposition using NTP technology was investigated through a series of experiments, including voltage, frequency, water content, initial concentration, flow rate, and oxygen content. The experimental results show that the energy injected into the NTP system has a positive correlation to voltage and frequency. Oxygen has the greatest influence on TCB decomposition. The optimal reaction condition was at 15 kV, 1000 Hz, an initial concentration of 20 mg m −3 , a flow rate of 2 l min −1 , H 2 O at 4%, and O 2 at 0%. Under this condition, the TCB removal efficiency could reach 92%. According to the generated product backstepping, the hydroxyl radical (•OH) plays an important role in TCB decomposition due to its strong oxidation, which participates in the dechlorination and oxidation reactions as free radicals, and the possible decomposition pathway of TCB by NTP is inferred from the identified byproducts. It is of great significance to investigate the influence of the parameters of TCB decomposition using NTP technology in order to provide references for industrial application.

“…Guan et al also found that the NO x removal efficiency was improved significantly at lower temperatures in the NH 3 -SCR system because C 3 H 6 could be decomposed into useful intermediates such as methyl, methoxy radicals, and partial oxidation products of C 3 H 6 conversion, including peroxyl radicals and hydro-peroxy radicals [31]. In the presence of C 3 H 6 , specific pathways between NO and hydrocarbons could occur in the NTP-SCR system, such as the following chemical reactions [32][33][34]: It is noted that in practical applications, H 2 O is an inevitable combustion product in marine diesel engine exhaust and could generate a variety of strong oxidizing free radicals though NTP gas-phase reaction, which usually contributes to the oxidative removal of NO x [35]. Numerous investigations have indicated that the conversion of NO to NO 2 is an important intermediate step in the reduction of NO x to N 2 , and the most efficient approach to achieve it is using NTP combined with an SCR catalyst.…”

Section: Effect Of C 3 H 6 On No X Conversionmentioning

confidence: 99%

Selective catalytic reduction of NO_x with NH₃ assisted by non-thermal plasma over CeMnZrO_x@TiO₂ core–shell catalyst

Zhu¹,

Zhang²,

Li³

et al. 2022

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The presented work reports the selective catalytic reduction (SCR) of NO x assisted by dielectric barrier discharge plasma via simulating marine diesel engine exhaust, and the experimental results demonstrate that the low-temperature activity of NH3-SCR assisted by non-thermal plasma is enhanced significantly, particularly in the presence of a C3H6 additive. Simultaneously, CeMnZrO x @TiO2 exhibits strong tolerance to SO2 poisoning and superior catalytic stability. It is worthwhile to explore a new approach to remove NO x from marine diesel engine exhaust, which is of vital significance for both academic research and practical applications.