Effect of H2O2 on the treatment of NO and NO2 using a Mg–Al oxide slurry

Kameda, Tomohito; Kodama, Aki; Yoshioka, Toshiaki

doi:10.1016/j.chemosphere.2014.08.025

Cited by 16 publications

(11 citation statements)

References 16 publications

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“…Currently, the main technical process of NO x wet absorption from exhaust gas is to preoxidize NO in the gas or liquid phase and then absorb NO x with a certain degree of oxidation in the absorption system. Many mature oxidation technologies can oxidize NO to NO 2 effectively, such as hydrogen peroxide (H 2 O 2 ), , sodium hypochlorite (NaClO), ozone (O 3 ), ,, and nonthermal plasma (NTP). , This paper mainly studies NO 2 wet absorption, which is critical for the NO x wet absorption technique.…”

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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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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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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“…The results showed that when the mole ratio of NH 4 HSO 3 /(NH 4 HSO 3 + (NH 4 ) 2 SO 3 ) increased from 0 to 0.8, the conversion efficiency of NO decreased from 62.1 to 54.8 and 88.6 to 81.3% for ATP and L-ATP1, respectively. When the proportion of NH 4 HSO 3 increased in the solution, H + would form by the reaction of hydrogen bisulfite with NO and NO 2 , resulting in an increase of the acidity of the solution, which increased the mass transfer resistance of gas–liquid phase and inhibited the progress of chemical reactions . At the same time, it can be seen that the effect of sulfite ratio on NO 2 absorption is greater than NO. …”

Section: Resultsmentioning

confidence: 99%

Modified Fe-Rich Palygorskite as an Efficient and Low-Cost Heterogeneous Fenton Catalyst for NO_x and SO₂ Removal

Yang

et al. 2020

Energy Fuels

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In this article, the entire removal process was based on a cycle absorption system in which a primary-absorber was used to scrub SO 2 by urea, then residual NO and SO 2 could be oxidized by the vaporized H 2 O 2 /catalysts in the catalytic system, and finally, the soluble gaseous pollutants and the remaining gaseous oxidants were absorbed by ammonium sulfite that was produced from the primary-absorber. The complex catalysts formed by iron recovery from the bauxite residue (red mud) were restructured with adenosine triphosphate (ATP) to generate mesopores with surface-active sites (FeOH) for efficient H 2 O 2 catalysis. Further, 95.2% SO 2 and 88.6% NO were removed from flue gas under the operation conditions where SO 2 concentration was 2000 ppm, NO concentration was 500 ppm, O 2 concentration was 7%, CO 2 concentration was 10%, catalytic temperature was 140 °C, H 2 O 2 feeding rate was 1.5 mL/h, and the total gas flow rate was 1.5 L/min. The results suggested that the catalytic performance is closely related to the structure of support ATP, which was elucidated by a series of experiments in different Fe loadings and BET characterization. From electron spin resonance (ESR) results, H 2 O 2 generally decompose not only into the • OH free radical by iron oxide but also into • HOO and related reactive oxygen species. According to the results of X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (TPR), the content of FeOH and lattice oxygen in the modified ATP catalyst played an important role in the adsorption of H 2 O 2 on the protonated surface of the low-acid catalyst. Furthermore, the rational catalytic mechanism of catalyst/H 2 O 2 at low and high temperatures (corresponding to 140 and 200 °C) was proposed by transient response experiments.

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“…Redistribution subject to ECS terms of use (see 18.236.120. 13 Downloaded on 2018-05-11 to IP Ni(I) leads to the formation of NH 3 and N 2 products. Simultaneously, Co(III) was generated at the anodic half-cell in the 5 M H 2 SO 4 solution and was used to oxidize NO by electro-scrubbing.…”

Section: Discussionmentioning

confidence: 99%

“…10,11 Heterogeneous catalytic oxidation at the gas phase produced NO 2 , 12 but solution phase oxidation by ozone and H 2 O 2 produced the NO 3 − product. 1,13 Because of the catalytic reaction, NO is solubilized in an aqueous solution, otherwise it less soluble or insoluble in an aqueous solution.…”

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confidence: 99%

Synergistic Effect of Mediated Electrochemical Reduction and Mediated Electrochemical Oxidation on NO Removal by Electro-Scrubbing

Muthuraman

Ramu

Ahn

et al. 2016

J. Electrochem. Soc.

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A combined MER (mediated electrochemical reduction) and MEO (mediated electrochemical oxidation) approach was examined for the first time for the efficient removal of NO by electro-scrubbing. The generation of a mediator (Ni(I) from Ni(II)(CN) 4 2− in 9 M KOH) by electrochemical reduction was identified by the changes in the ORP value and potentiometric titration. The Ni(I) formation found to be 9% (4.3 mM) in 2 h electrolysis, which is decreased to 1.83 mM (4%) during addition of NO demonstrates NO removal occurred. The MER of NO at the cathodic half-cell by electro-scrubbing revealed the formation of NH 3 and N 2 . The reductive removal efficiency of NO was almost 100% up to a gas flow rate of 0.25 g min −1 . At the anodic half-cell, the Co(III) mediator from Co(II)SO 4 in 5 M H 2 SO 4 was generated electrochemically with concomitant conversion of NO to NO 3 − in the solution phase with a removal efficiency of 28%. The combination of MEO and MER with electro-scrubbing demonstrates 97% removal efficiency of NO up to 0.5 g min −1 . The combined removal approach is more suitable for high concentrated NO with energy efficiency of 0. Abundantly generated nitric oxide (NO) gas that includes power plant and steel plant etc., is decomposed by many technologies, such as wet scrubbing, catalytic oxidation, and selective catalytic reduction (SCR).1-3 The reduction of NO leads a combination of cationic intermediates and products, N 2 O, NH 2 OH, N 2 , and NH 3 , in the solution phase. [4][5][6] The reduction products varied depending on the catalyst and experimental conditions: on TiO 2 in the colloid solutions to produce NH 3 ; 4 in heterogeneous catalytic reduction process with NH 3 as the reactant produced N 2 ; 7,8 and N 2 O formed on boron-doped graphene method.9 At the same time, the oxidation of NO leads to the anionic products of NO 2 and NO 3 − . 10,11 Heterogeneous catalytic oxidation at the gas phase produced NO 2 , 12 but solution phase oxidation by ozone and H 2 O 2 produced the NO 3 − product. 1,13 Because of the catalytic reaction, NO is solubilized in an aqueous solution, otherwise it less soluble or insoluble in an aqueous solution.14 Using this approach, many oxidant-15,16 and reductant-17 containing wet-scrubbing processes have been adopted in NO removal. Note that the above methods require a continuous catalyst or reactant feed to make the process sustainable.An electron considered to be a green catalyst and can be feed continuously to regenerate the spent catalyst sustainably. Using this approach, electrogenerated Ce(IV) and Mn(III) mediators have been used to oxidize NOx to NO 3 − in HNO 3 medium. 18,19 In a similar method, electrogenerated Ag(II) with a wet scrubber in the name of 'electro-scrubbing' have used NOx oxidation to NO 2 in a single stage scrubber and NO 3 − in a two stage scrubber column. 20 In the presence of SO 2 in NO oxidation using the electrogenerated Ag(II) mediator in highly concentrated nitric acid have shown NO 2 with 60 to 80% of NO 3 − formation. [21][22][23] Note that unless...

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Effect of H2O2 on the treatment of NO and NO2 using a Mg–Al oxide slurry

Cited by 16 publications

References 16 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

Modified Fe-Rich Palygorskite as an Efficient and Low-Cost Heterogeneous Fenton Catalyst for NO_x and SO₂ Removal

Synergistic Effect of Mediated Electrochemical Reduction and Mediated Electrochemical Oxidation on NO Removal by Electro-Scrubbing

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Effect of H2O2 on the treatment of NO and NO2 using a Mg–Al oxide slurry

Cited by 16 publications

References 16 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

Modified Fe-Rich Palygorskite as an Efficient and Low-Cost Heterogeneous Fenton Catalyst for NOx and SO2 Removal

Synergistic Effect of Mediated Electrochemical Reduction and Mediated Electrochemical Oxidation on NO Removal by Electro-Scrubbing

Contact Info

Product

Resources

About

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

Modified Fe-Rich Palygorskite as an Efficient and Low-Cost Heterogeneous Fenton Catalyst for NO_x and SO₂ Removal