Absorption of NO2 into aqueous (NH4)2SO3 solution in a stirred tank reactor

Pan, Weiguo; Zhang, Xiaobo; Ren, Jianxing; Jin, Qiang; Xu, Hang

doi:10.1002/ep.11645

Cited by 18 publications

(5 citation statements)

References 21 publications

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“…Effect of the Initial NO 2 Concentration on NO 2 Absorption by Na 2 SO 3 and Na 2 SO 3 /NaHSO 3 . As shown in Figure 7, increasing the initial concentration of NO 2 increased the NO x absorption efficiency from 95.4% to 97.8% in the Na 2 SO 3 absorption system and from 96.0% to 97.8% in the Na 2 SO 3 /NaHSO 3 absorption system, and these results are compatible with the results of Guo et al 21 As explained above, the absorption process was mainly controlled by the gas film when the S(IV) concentration exceeded 0.2 mol/L (Figure ). In addition, the gas-phase driving force increased as the initial NO 2 concentration increased, and a high initial NO 2 concentration enhanced the amount of NO 2 dissolved in the liquid phase, which promoted the rates of reactions 6−9.…”

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confidence: 90%

“…Although the NO 2 absorption performance by sulfite is good, the main N-containing products from the absorption of NO 2 in solution are nitrate and nitrite. ,, Nitrate can induce the fertilization of seawater and reduce the dissolved oxygen content in seawater, hence affecting biodiversity. According to the Marine Environment Protection Committee (MEPC), the nitrate concentration in scrubber water should not exceed 60 mg/L. − Moreover, nitrite is extremely unstable and easily oxidized to nitrate.…”

Section: Introductionmentioning

confidence: 99%

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A Prospective Method for Absorbing NO₂ by the Addition of NaHSO₃ to Na₂SO₃-Based Absorbents for Ship NO_x Wet Absorption

Zhang

Zhou

et al. 2020

Energy Fuels

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A high nitrate concentration in scrubber water is a major factor that restricts ship applications of NO x wet absorption technology. In this paper, an absorption system (Na 2 SO 3 /NaHSO 3 ) that can effectively improve NO 2 absorption and reduce the concentrations of nitrate and nitrite was studied. Several factors that affect the NO x absorption efficiency and the concentrations of nitrate and nitrite were investigated in a bubble reactor by using Na 2 SO 3 and Na 2 SO 3 /NaHSO 3 . In addition, the reaction mechanism for the process of NO 2 absorption was deduced. The results illustrate that increases in S(IV) concentration and initial NO 2 concentration could enhance the NO x absorption efficiency while increases in the NO/NO 2 ratio and SO 2 concentration decreased the NO x absorption efficiency. Moreover, the maximum NO x absorption efficiency was 97.8% at 0.15 mol/L S(IV) and 1400 ppm of NO 2 when using the Na 2 SO 3 /NaHSO 3 absorption system. The S(IV) concentration was the main factor affecting the NO x absorption efficiency and the concentrations of nitrate and nitrite. Increasing the SO 2 concentration slightly affected the NO x absorption efficiency but was beneficial for decreasing the concentrations of nitrate and nitrite. The performance of the Na 2 SO 3 / NaHSO 3 absorption system was better than that of Na 2 SO 3 in the presence of oxygen. Furthermore, the minimum concentrations of nitrate and nitrite were 13.5 and 0 mg/L, respectively, in the Na 2 SO 3 /NaHSO 3 absorption system for 1100 ppm of NO 2 and 0.3 mol/L S(IV) and were much lower than current regulations for scrubber water. Finally, compared with other experimental results, the Na 2 SO 3 /NaHSO 3 absorption system exhibits great potential for ship NO x wet absorption, and the addition of NaHSO 3 plays a key role in decreasing the concentrations of nitrate and nitrite.

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confidence: 90%

Section: Introductionmentioning

confidence: 99%

A Prospective Method for Absorbing NO₂ by the Addition of NaHSO₃ to Na₂SO₃-Based Absorbents for Ship NO_x Wet Absorption

Zhang

Zhou

et al. 2020

Energy Fuels

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“…13,14 In light of the difficulty in coupling discrete SO 2 and NO x removal approaches, developing an effective technology for simultaneous removal of SO 2 and NO x is a desired goal. Various technologies have been developed for simultaneous removal of SO 2 and NO x , such as solid-phase absorption, 15,16 nonthermal plasma, 17,18 enhanced wet scrubbing, 7,19,20 etc. WFGD can be used for the combined removal of NO x and SO 2 provided that the NO x is in a highly oxidized state with high water solubility.…”

Section: Introductionmentioning

confidence: 99%

Investigation of NO Removal with Ozone Deep Oxidation in Na₂CO₃ Solution

et al. 2019

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Wet flue gas desulfurization (WFGD) provides highly efficient SO 2 removal in industrial flue gas treatment. Although NO and NO 2 are not readily absorbed in the traditional desulfurization wash tower, deep oxidation with ozone can promote the formation of N 2 O 5 that is absorbed in the washing fluid, making possible simultaneous denitration and desulfurization in the WGFD unit. This paper presents a survey of operating parameters for NO x removal after ozone deep oxidation using a Na 2 CO 3 -based WFGD. The effects of preoxidation time, Na 2 CO 3 aqueous solution concentration, spray liquid/gas ratio, gas residence time in wash tower, and SO 2 concentration on NO x removal efficiency were investigated systematically in a variable-configuration experimental setup. The results demonstrate that preoxidation time was the most sensitive factor in N 2 O 5 formation, although oxidation continued in the wash tower. Thus, one strategy for a system where physical constraints limit the volume of the oxidation chamber is to extend the flue gas residence time in the wash tower. Increasing the liquid/gas ratio and Na 2 CO 3 solution concentration gave some enhancement on the wet absorption process. Under optimal laboratory conditions, 95% NO x removal efficiency was achieved. Addition of SO 2 yielded a slight inhibition for NO x removal, and under industrial relevant operating conditions, 98% SO 2 and 62% NO x removal was achieved during 50 min experimental runs.

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“…Scrubbing tests conducted in previous studies revealed that sodium sulfite (Na 2 SO 3 ) can effectively reduce aqueous NO 2 in scrubbing liquor and promote the absorption of NO 2 from the influent gas . These studies used pure NO or NO 2 in air streams and alkaline Na 2 SO 3 solution as the scrubbing liquor.…”

Section: Resultsmentioning

confidence: 99%

Reduction of nitrogen dioxide from etching vent gases by scrubbing with caustic sodium sulfide solution

Chou

2013

J. Chem. Technol. Biotechnol.

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BACKGROUND Acids and nitrogen dioxide (NO2) in gases that are vented from Al‐etching operations for the production of thin‐film transistor‐liquid crystal displays (TFT‐LCD) are harmful to the environment. Scrubbing the gases using traditional caustic liquids with high salinities is ineffective in removing NO2. This work develops practices for improving the removal of NO2 by adding reducing agents to the scrubbing liquids. RESULTS Field results reveal that Na2SO3 is a less effective agent for reducing NO2 than is Na2S, because it has a stronger reduction ability. In this work, when the scrubber parameters were a packing height of 1.0–2.0 m, a liquid‐to‐gas ratio L/G of 0.48–2.64 L m−3 and a superficial gas velocity U of 0.66–2.08 m s−1, and for influent NO2 concentrations of several tenths of ppm, the NO2 removal depended more on the sulfide dose than on the mass‐transfer rate of NO2 to the liquid. CONCLUSIONS A sodium sulfide dose of 1.53±0.22 kg/(kg NO2 removed) over influent NO2 at a concentration 30–50 ppm was obtained. This value was much higher than the stoichiometric value for the reduction of NO2 to nitrite. Sulfide addition using an ORP‐controlled mode with an ORP of −400 ± 10 mV and a pH of 12.5 ± 0.1 in the scrubbing liquid is suggested for reducing chemical costs and obtaining the desired NO2 concentration of exhaust gas. © 2013 Society of Chemical Industry

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Absorption of NO₂ into aqueous (NH₄)₂SO₃ solution in a stirred tank reactor

Cited by 18 publications

References 21 publications

A Prospective Method for Absorbing NO₂ by the Addition of NaHSO₃ to Na₂SO₃-Based Absorbents for Ship NO_x Wet Absorption

A Prospective Method for Absorbing NO₂ by the Addition of NaHSO₃ to Na₂SO₃-Based Absorbents for Ship NO_x Wet Absorption

Investigation of NO Removal with Ozone Deep Oxidation in Na₂CO₃ Solution

Reduction of nitrogen dioxide from etching vent gases by scrubbing with caustic sodium sulfide solution

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Absorption of NO2 into aqueous (NH4)2SO3 solution in a stirred tank reactor

Cited by 18 publications

References 21 publications

A Prospective Method for Absorbing NO2 by the Addition of NaHSO3 to Na2SO3-Based Absorbents for Ship NOx Wet Absorption

A Prospective Method for Absorbing NO2 by the Addition of NaHSO3 to Na2SO3-Based Absorbents for Ship NOx Wet Absorption

Investigation of NO Removal with Ozone Deep Oxidation in Na2CO3 Solution

Reduction of nitrogen dioxide from etching vent gases by scrubbing with caustic sodium sulfide solution

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Absorption of NO₂ into aqueous (NH₄)₂SO₃ solution in a stirred tank reactor

A Prospective Method for Absorbing NO₂ by the Addition of NaHSO₃ to Na₂SO₃-Based Absorbents for Ship NO_x Wet Absorption

A Prospective Method for Absorbing NO₂ by the Addition of NaHSO₃ to Na₂SO₃-Based Absorbents for Ship NO_x Wet Absorption

Investigation of NO Removal with Ozone Deep Oxidation in Na₂CO₃ Solution