An integrated method for determining nitrogen oxide (NOx) emissions at nitric acid plants

Margeson, John H.; Knoll, J.; Midgett, M.R.; Oldaker, Guy B.; Loder, K.R.; Grohse, Peter; Gutknecht, W. F.

doi:10.1021/ac00277a079

Cited by 8 publications

(15 citation statements)

References 13 publications

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“…The NH 4 + oxidation rate in solution is a linear function of the NH 4 + concentration [Margeson et al, 1984] and independent of the NO 3 À solution concentrations for collection conditions in this study where solution pH did not change significantly following collections. Based on the 2.8% increase in NO 3 À observed due to NH 3 oxidation interference at 200 ppmv NH 3 after 7 days [Margeson et al, 1984], our 200 ppbv NH 3 concentration should result in a negligible 0.0028% interference. Our experiments demonstrate negligible interference in that blank solutions with added NH 4 + reduced 1 week after solution preparation had consistent NO 3 À concentrations (within 0.2 μM) and δ 15 N-NO x (within 0.9‰) relative to those reduced 1 day after solution preparation.…”

Section: No X Collection and Isotopic Analysismentioning

confidence: 60%

“…To evaluate the potential for ammonia (NH 3 ) interference via solution collection and oxidation to NO 3 − over time [ Margeson et al ., ], we added NH 4 + to simulate solution collection of vehicle NH 3 emissions at maximum expected on‐road concentrations (~200 ppbv NH 3 ) [ Sun et al ., ]. The NH 4 + oxidation rate in solution is a linear function of the NH 4 + concentration [ Margeson et al ., ] and independent of the NO 3 − solution concentrations for collection conditions in this study where solution pH did not change significantly following collections. Based on the 2.8% increase in NO 3 − observed due to NH 3 oxidation interference at 200 ppmv NH 3 after 7 days [ Margeson et al ., ], our 200 ppbv NH 3 concentration should result in a negligible 0.0028% interference.…”

Section: Methodsmentioning

confidence: 99%

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Vehicle NO_x emission plume isotopic signatures: Spatial variability across the eastern United States

et al. 2017

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On‐road vehicle nitrogen oxide (NOx) sources currently dominate the U.S. anthropogenic emission budgets, yet vehicle NOx emissions have uncertain contributions to oxidized nitrogen (N) deposition patterns. Isotopic signatures serve as a potentially valuable observational tool to trace source contributions to NOx chemistry and N deposition, yet in situ emission signatures are underconstrained. We characterize the spatiotemporal variability of vehicle NOx emission isotopic signatures (δ15N‐NOx) representative of U.S. vehicle fleet‐integrated emission plumes. A novel combination of on‐road mobile and stationary urban measurements is performed using a field and laboratory‐verified technique for actively capturing NOx in solution to quantify δ15N‐NOx at hourly resolution. On‐road δ15N‐NOx upwind of Providence, RI, ranged from −7 to −3‰. Simultaneous urban background δ15N‐NOx observations showed comparable range and variations with on‐road measurements, suggesting that vehicles dominate NOx emissions in the Providence area. On‐road spatial δ15N‐NOx variations of −9 to −2‰ were observed under various driving conditions in six urban metropolitan areas and rural interstate highways during summer and autumn in the U.S. Northeast and Midwest. Although isotopic signatures were insensitive to on‐road driving mode variations, statistically significant correlations were found between δ15N‐NOx and NOx emission factor extremes associated with heavy diesel emitter contributions. Overall, these results constrain an isotopic signature of fleet‐integrated roadway NOx emission plumes, which have important implications for distinguishing vehicle NOx from other sources and tracking emission contributions to NOx chemistry and N deposition.

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Section: No X Collection and Isotopic Analysismentioning

confidence: 60%

Section: Methodsmentioning

confidence: 99%

Vehicle NO_x emission plume isotopic signatures: Spatial variability across the eastern United States

et al. 2017

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“…2. Make sampling solutions using 1 M potassium permanganate (KMnO 4 ) stock solution and 10 M sodium hydroxide (NaOH) 10 , and then dilute the solution with ultrapure water to the correct volume. NOTE: Purchase premade solutions because they tend to contain lower "blank" NO 3 -concentrations than other forms.…”

Section: Solution Preparationmentioning

confidence: 99%

Automated, High-resolution Mobile Collection System for the Nitrogen Isotopic Analysis of NO<sub>x</sub>

Wojtal

Miller

O'Conner

et al. 2016

JoVE

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Nitrogen oxides (NO x = NO + NO 2 ) are a family of atmospheric trace gases that have great impact on the environment. NO x concentrations directly influence the oxidizing capacity of the atmosphere through interactions with ozone and hydroxyl radicals. The main sink of NO x is the formation and deposition of nitric acid, a component of acid rain and a bioavailable nutrient. NO x is emitted from a mixture of natural and anthropogenic sources, which vary in space and time. The collocation of multiple sources and the short lifetime of NO x make it challenging to quantitatively constrain the influence of different emission sources and their impacts on the environment. Nitrogen isotopes of NO x have been suggested to vary amongst different sources, representing a potentially powerful tool to understand the sources and transport of NO x . However, previous methods of collecting atmospheric NO x integrate over long (week to month) time spans and are not validated for the efficient collection of NO x in relevant, diverse field conditions. We report on a new, highly efficient field-based system that collects atmospheric NO x for isotope analysis at a time resolution between 30 min and 2 hr. This method collects gaseous NO x in solution as nitrate with 100% efficiency under a variety of conditions. Protocols are presented for collecting air in urban settings under both stationary and mobile conditions. We detail the advantages and limitations of the method and demonstrate its application in the field. Data from several deployments are shown to 1) evaluate field-based collection efficiency by comparisons with in situ NO x concentration measurements, 2) test the stability of stored solutions before processing, 3) quantify in situ reproducibility in a variety of urban settings, and 4) demonstrate the range of N isotopes of NO x detected in ambient urban air and on heavily traveled roadways.

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“…Most other plants tested use selective catalytic reduction (SCR) or selective noncatalytic reduction (SNCR), both of which use an injection of ammonia into the stream to reduce NO x emissions (i.e., 4NO + 4 NH 3 + O 2 → 4N 2 + 6H 2 O). Ammonia is known to interfere with certain NO x collection methods, 16 and the H 2 SO 4 and H 2 O 2 collection utilized by Felix et al 10 in the rest of the power plants is very similar to the Environmental Protection Agency method for ammonia collection (EPA Conditional Test Method 027). Therefore, it is unknown if the difference in δ 15 N-NO x measured in the SCR/SNCR (13.6‰ to 25.6‰) and nonammonia NO x reduction (9.0‰ to 12.6‰) power plants (Figure 1) is driven by fractionation in the NO x removal step or by possible ammonia interference in the measurements.…”

mentioning

confidence: 99%

Collection of NO and NO₂ for Isotopic Analysis of NO_x Emissions

et al. 2014

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There have been several measurements made of the nitrogen isotopic composition of gaseous NOx (NOx = NO + NO2) from various emission sources, utilizing a wide variety of methods to collect the NOx in solution as nitrate or nitrite. However, previous collection techniques have not been verified for complete or efficient capture of NOx such that the isotopic composition of NOx remains unaltered during collection. Here, we present a method of collecting NOx (NO + NO2) in solution as nitrate to evaluate the nitrogen isotopic composition of the NOx (δ(15)N-NOx). Using a 0.25 M KMnO4 and 0.5 M NaOH solution, quantitative NOx collection was achieved under a variety of conditions in laboratory and field settings, allowing for isotopic analysis without correcting for fractionations. The uncertainty across the entire analytic procedure is ±1.5‰ (1σ). With this method, a more robust inventory of NOx source isotopic composition is possible, which has implications for studies of air quality and acid deposition.

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An integrated method for determining nitrogen oxide (NOx) emissions at nitric acid plants

Cited by 8 publications

References 13 publications

Vehicle NO_x emission plume isotopic signatures: Spatial variability across the eastern United States

Vehicle NO_x emission plume isotopic signatures: Spatial variability across the eastern United States

Automated, High-resolution Mobile Collection System for the Nitrogen Isotopic Analysis of NO<sub>x</sub>

Collection of NO and NO₂ for Isotopic Analysis of NO_x Emissions

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An integrated method for determining nitrogen oxide (NOx) emissions at nitric acid plants

Cited by 8 publications

References 13 publications

Vehicle NOx emission plume isotopic signatures: Spatial variability across the eastern United States

Vehicle NOx emission plume isotopic signatures: Spatial variability across the eastern United States

Automated, High-resolution Mobile Collection System for the Nitrogen Isotopic Analysis of NO<sub>x</sub>

Collection of NO and NO2 for Isotopic Analysis of NOx Emissions

Contact Info

Product

Resources

About

Vehicle NO_x emission plume isotopic signatures: Spatial variability across the eastern United States

Vehicle NO_x emission plume isotopic signatures: Spatial variability across the eastern United States

Collection of NO and NO₂ for Isotopic Analysis of NO_x Emissions