NOx scrubbing with H2O2/HNO3 solutions achieved with a laboratory bubble contactor

Ghriss, Ons; Amor, Hédi Ben; Chekir, Hassen; Jeday, Mohamed Razak

doi:10.1007/s10163-019-00912-7

Cited by 4 publications

(4 citation statements)

References 24 publications

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“…For example, flue gas impurities such as nitrogen oxides (NO x ) and sulfur oxides (SO x ) are soluble in alkaline CO 2 capture solutions. SO x reacts in solution to form SO 3 2– and SO 4 2– , while NO x reacts to form NO 2 – and NO 3 – . , These contaminants are redox-active and can compete with CO2RR at the cathode. Experimentation revealed that SO x impurities do not decrease CO2RR in the reactive carbon electrolyzer as they do in CO 2 electrolyzers, but ppm-level concentrations of NO x anions in the feedstock cause >50% losses in reaction selectivities.…”

Section: Co2 and Reactive Carbon Electrolyzer Configurationsmentioning

confidence: 99%

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Reactive Carbon Capture Enables CO₂ Electrolysis with Liquid Feedstocks

Pimlott,

Kim,

Berlinguette

2024

Acc. Chem. Res.

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Metrics & MoreArticle Recommendations * sı Supporting Information CONSPECTUS: The electrochemical reduction of carbon dioxide (CO2RR) is a promising strategy for mitigating global CO 2 emissions while simultaneously yielding valuable chemicals and fuels, such as CO, HCOO − , and C 2 H 4 . This approach becomes especially appealing when integrated with surplus renewable electricity, as the ensuing production of fuels could facilitate the closure of the carbon cycle. Despite these advantages, the realization of industrial-scale electrolyzers fed with CO 2 will be challenged by the substantial energy inputs required to isolate, pressurize, and purify CO 2 prior to electrolysis.To address these challenges, we devised an electrolyzer capable of directly converting reactive carbon solutions (e.g., a bicarbonaterich eluent that exits a carbon capture unit) into higher value products. This "reactive carbon electrolyzer" operates by reacting (bi)carbonate with acid generated within the electrolyzer to produce CO 2 in situ, thereby facilitating CO2RR at the cathode. This approach eliminates the need for expensive CO 2 recovery and compression steps, as the electrolyzer can then then coupled directly to the CO 2 capture unit. This Account outlines our endeavors in developing this type of electrolyzer, focusing on the design and implementation of materials for electrocatalytic (bi)carbonate conversion. We highlight the necessity for a permeable cathode that allows the efficient transport of (bi)carbonate ions while maintaining a sufficiently high catalytic surface area. We address the importance of the supporting electrolyte, detailing how (bi)carbonate concentration, counter cations, and ionic impurities impact selectivity for products formed in the electrolyzer. We also catalog state-of-the-art performance metrics for reactive carbon electrolyzers (i.e., Faradaic efficiency, full cell voltage, CO 2 utilization efficiency) and outline strategies to bridge the gap between these values and those required for commercial operation Collectively, these findings contribute to the ongoing efforts to realize industrial-scale electrochemical reactors for CO 2 conversion, bringing us closer to a sustainable and closed-loop carbon cycle.

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Section: Co2 and Reactive Carbon Electrolyzer Configurationsmentioning

confidence: 99%

“…. 58,59 These contaminants are redox-active and can compete with CO2RR at the cathode. Experimentation revealed that SO x impurities do not decrease CO2RR in the reactive carbon electrolyzer as they do in CO 2 electrolyzers, 53 but ppm-level concentrations of NO x anions in the feedstock cause >50% losses in reaction selectivities.…”

mentioning

confidence: 99%

Reactive Carbon Capture Enables CO₂ Electrolysis with Liquid Feedstocks

Pimlott,

Kim,

Berlinguette

2024

Acc. Chem. Res.

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“…In addition to that, the NO 2 mass transfer rate in water also plays an important role as it further converts to HNO 3 . Numerous reports have been published on the chemistry of conversion of NO 2 to HNO 3 in the aqueous system. ,, Some important features were also reported in the past regarding the effect of using hydrogen peroxide to the aqueous medium . To be precise, in the presence of H 2 O 2 , the intermediate formation of HNO 2 is prevented and it further oxidizes to HNO 3 .…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Reaction Kinetics for Removal of NO_x by Ozone and Hydrogen Peroxide

Khuntia

Sinha

Mohan

2020

Ind. Eng. Chem. Res.

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In this article, the kinetics of the ozone and hydrogen peroxide-based NO2 removal from flue gas has been evaluated using the well-known two-film theory. The effectiveness of the rate of absorption of NO2 has been tested by the effect of pH, temperature, H2O2 concentration, and so forth. This study also includes the comparison of the Hatta number (Ha) at various experimental conditions. It was observed that the reaction of NO2 is first order in nature with both ozone and hydrogen peroxide. The effect of SO2 concentration on the absorption of NO2 was negligible. However, the absorption efficiency decreases in the presence of higher SO2 concentration in the peroxone process. The predicted model shows a good fit with the experimental results for various NO2 inlet concentrations. The optimum pH for NO2 absorption for ozonation and peroxone processes was 8. At 318 K, absorption of NO2 shows the maximum value for the ozonation process, whereas for the peroxone process, it was 328 K. The effect of H2O2 on the absorption of NO2 in the aqueous phase was prominent with high Ha values. It was observed that NO2 absorption increases rapidly when H2O2 concentration is increased from 0 to 0.3 mol·L–1. In the zone of 0.5–3.5 mol·L–1 H2O2 concentration, the rate of NO2 absorption was slow.

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“…SO x reacts with water to form SO 3 2– and SO 4 2– , while NO x reacts to form NO 2 – and NO 3 – (eqs 4 and 5). , These contaminants are redox-active and may compete with the CO 2 reduction reaction (CO2RR) at the cathode. Consequently, decreases in CO2RR product formation due to these anions could render the use of reactive carbon solutions impractical.…”

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confidence: 99%

Impurity-Resistant CO₂ Reduction Using Reactive Carbon Solutions

et al. 2023

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Electrolyzers that electrochemically convert aqueous (bi)carbonate solutions (solutions containing captured CO2, or “reactive carbon solutions”) into commodity chemicals couple CO2 capture with CO2 conversion. Industrial exhaust streams contain nitrogen oxides (NO x ) and sulfur oxides (SO x ) that form redox-active anions in reactive carbon solutions that can interfere with downstream CO2 reduction. We therefore designed experiments to test how impurities produced from the dissolution of NO x (NO2 – and NO3 –) and SO x (SO3 2– and SO4 2–) impact the electrochemical conversion of (bi)carbonate to CO. We found that CO production was unaffected by SO x compounds in a 3.0 M KHCO3 feedstock, but 2000 ppm of NO x impurities decreased CO selectivity from ∼60% to <5%. This decrease was caused by the preferential reduction of NO2 – and NO3 – over CO2. Our study establishes tolerance limits for common flue gas impurities in reactive carbon solutions and provides strategies to mitigate toxification effects.

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NOx scrubbing with H2O2/HNO3 solutions achieved with a laboratory bubble contactor

Cited by 4 publications

References 24 publications

Reactive Carbon Capture Enables CO₂ Electrolysis with Liquid Feedstocks

Reactive Carbon Capture Enables CO₂ Electrolysis with Liquid Feedstocks

Evaluation of Reaction Kinetics for Removal of NO_x by Ozone and Hydrogen Peroxide

Impurity-Resistant CO₂ Reduction Using Reactive Carbon Solutions

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NOx scrubbing with H2O2/HNO3 solutions achieved with a laboratory bubble contactor

Cited by 4 publications

References 24 publications

Reactive Carbon Capture Enables CO2 Electrolysis with Liquid Feedstocks

Reactive Carbon Capture Enables CO2 Electrolysis with Liquid Feedstocks

Evaluation of Reaction Kinetics for Removal of NOx by Ozone and Hydrogen Peroxide

Impurity-Resistant CO2 Reduction Using Reactive Carbon Solutions

Contact Info

Product

Resources

About

Reactive Carbon Capture Enables CO₂ Electrolysis with Liquid Feedstocks

Reactive Carbon Capture Enables CO₂ Electrolysis with Liquid Feedstocks

Evaluation of Reaction Kinetics for Removal of NO_x by Ozone and Hydrogen Peroxide

Impurity-Resistant CO₂ Reduction Using Reactive Carbon Solutions