Time-resolved ammonia measurement in vehicle exhaust

Mohn, Joachim; Forss, Anna Maria; Brühlmann, Stefan; Zeyer, Kerstin; Lüscher, Roland; Emmenegger, Lukas; Novak, Philippe; Heeb, Norbert V.

doi:10.1504/ijep.2004.005548

Cited by 31 publications

(15 citation statements)

References 18 publications

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“…The temperature of the tube was increased by 1.5 K min −1 to a final temperature of 543 K. Downstream of the heated glass tube the reaction gas was diluted with 250 mL min −1 high‐purity synthetic air (99.999%, 20.5% O 2 in N 2 ) and transferred through a heated PTFE line (453 K, Winkler GmbH, Heidelberg, Germany) to a Fourier transform infrared (FTIR) spectrometer (CX‐4000, Gasmet Technologies Oy, Helsinki, Finland). The N 2 O mixing ratios and reaction by‐products (H 2 O, NH 3 , NO, NO 2 , HNO 3 ) were quantified in real‐time by FTIR spectroscopy . Downstream of the FTIR spectrometer the process gas was dynamically diluted to a constant N 2 O mole fraction of 90 ppm.…”

Section: Methodsmentioning

confidence: 99%

Reassessment of the NH₄NO₃ thermal decomposition technique for calibration of the N₂O isotopic composition

Mohn

Gutjahr

Toyoda

et al. 2016

Rapid Comm Mass Spectrometry

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The study reveals that the completeness and reproducibility of the NH NO decomposition reaction currently confine the anchoring of N O site-specific isotopic composition to the international isotope ratio scale AIR-N . The authors suggest establishing a set of N O isotope reference materials with appropriate site-specific isotopic composition, as community standards, to improve inter-laboratory compatibility. Copyright © 2016 John Wiley & Sons, Ltd.

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Section: Methodsmentioning

confidence: 99%

Reassessment of the NH₄NO₃ thermal decomposition technique for calibration of the N₂O isotopic composition

Mohn

Gutjahr

Toyoda

et al. 2016

Rapid Comm Mass Spectrometry

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“…Ammonia can be absorbed in condensed water or react with acidic compounds present in the exhaust or along the system. Previous studies have reported that ammonia sticks, and it is also adsorbed on the surfaces of sampling and analysis equipment, as well as on the dilute exhaust systems’ walls (Durbin et al 2002 ; Heeb et al 2006 , 2012 , 2008 ; Mohn et al 2004 ). Ammonia is delayed in the constant volume sampler (CVS) making time-resolved ammonia analysis from the CVS tunnel extremely difficult (Mohn et al 2004 ).…”

Section: Introductionmentioning

confidence: 99%

“…Previous studies have reported that ammonia sticks, and it is also adsorbed on the surfaces of sampling and analysis equipment, as well as on the dilute exhaust systems’ walls (Durbin et al 2002 ; Heeb et al 2006 , 2012 , 2008 ; Mohn et al 2004 ). Ammonia is delayed in the constant volume sampler (CVS) making time-resolved ammonia analysis from the CVS tunnel extremely difficult (Mohn et al 2004 ). As a result, exhaust tailpipe measurements have been considered to be the most appropriate approach for measuring vehicular ammonia emission on chassis dynamometer tests (Durbin et al 2002 ; Heeb et al 2006 , 2012 , 2008; Mohn et al 2004 ).…”

Section: Introductionmentioning

confidence: 99%

Intercomparison of real-time tailpipe ammonia measurements from vehicles tested over the new world-harmonized light-duty vehicle test cycle (WLTC)

Suarez-Bertoa

Zardini

Lilova

et al. 2015

Environ Sci Pollut Res

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Four light-duty vehicles (two diesel, one flex-fuel, and one gasoline vehicle) were tested as part of an intercomparison exercise of the world-harmonized light-duty vehicle test procedure (WLTP) aiming at measuring real-time ammonia emissions from the vehicles’ raw exhaust at the tailpipe. The tests were conducted in the Vehicle Emission Laboratory (VELA) at the European Commission Joint Research Centre (EC-JRC), Ispra, Italy. HORIBA, CGS, and the Sustainable Transport Unit of the Joint Research Centre (JRC) took part in the measurement and analysis of the four vehicles’ exhaust emissions over the world-harmonized light-duty vehicle test cycle class 3, version 5.3 using a HORIBA MEXA 1400 QL-NX, a CGS BLAQ-Sys, and the JRC Fourier transform infrared spectrometer, respectively. The measured ammonia concentrations and the emission profiles revealed that these three instruments are suitable to measure ammonia from the vehicles’ raw exhaust, presenting no significant differences. Furthermore, results showed that measurement of ammonia from the vehicle exhaust using online systems can be performed guaranteeing the reproducibility and repeatability of the results. While no ammonia was detected for any of the two diesel vehicles (even though, one was equipped with a selective catalytic reduction system), we report average ammonia emission factors 8–10 mg/km (average concentrations 20–23 ppm) and 10–12 mg/km (average concentrations 22–24 ppm) for the flex-fuel and gasoline vehicles, respectively.Electronic supplementary materialThe online version of this article (doi:10.1007/s11356-015-4267-3) contains supplementary material, which is available to authorized users.

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“…An infrared spectrum with 0.5 cm −1 optical resolution was recorded every three seconds, and trace gas (N 2 O, CO, CH 4 , CO 2 and H 2 O) mixing ratios were retrieved by classical least square fitting in selected wavelength regions (Mohn et al, 2004. Calibration spectra were recorded under identical instrumental and spectroscopic conditions from certified and diluted calibration gases or by continuous injection of liquids into nitrogen.…”

Section: On-line Ftir Analysis Of Mixing Ratiosmentioning

confidence: 99%

A liquid nitrogen-free preconcentration unit for measurements of ambient N<sub>2</sub>O isotopomers by QCLAS

et al. 2010

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Abstract. Important information about the biogeochemical cycle of nitrous oxide (N 2 O) can be obtained by measuring its three main isotopic species, 14 N 15 N 16 O, 15 N 14 N 16 O, and 14 N 14 N 16 O, and the respective site-specific relative isotope ratio differences δ 15 N α and δ 15 N β . Absorption laser spectroscopy in the mid-infrared is a direct method for the analysis of the 15 N isotopic composition of N 2 O, yet not sensitive enough for atmospheric N 2 O mixing ratios (320 ppb). To enable a fully-automated high precision analysis of N 2 O isotopic species at ambient mixing ratios, we built and optimized a liquid nitrogen-free preconcentration unit to be coupled to a quantum cascade laser (QCL) based spectrometer. During standard operation 10 l of ambient air are preconcentrated on a HayeSep D trap and desorbed in 50 ml of synthetic air. Rigorous tests were conducted, using FTIR, quantum cascade laser absorption spectroscopy (QCLAS), GC-FID and component-specific ozone and oxygen analysers to investigate recovery rates, conservation of isotopic signatures and spectral interferences after preconcentration. We achieve quantitative N 2 O recovery of >99% with only minor, statistically not significant isotopic fractionation and no relevant spectral interferences from other atmospheric constituents. The developed preconcentration unit also has the potential to be applied to other trace gases and their isotopic composition.

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Time-resolved ammonia measurement in vehicle exhaust

Cited by 31 publications

References 18 publications

Reassessment of the NH₄NO₃ thermal decomposition technique for calibration of the N₂O isotopic composition

Reassessment of the NH₄NO₃ thermal decomposition technique for calibration of the N₂O isotopic composition

Intercomparison of real-time tailpipe ammonia measurements from vehicles tested over the new world-harmonized light-duty vehicle test cycle (WLTC)

A liquid nitrogen-free preconcentration unit for measurements of ambient N<sub>2</sub>O isotopomers by QCLAS

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Time-resolved ammonia measurement in vehicle exhaust

Cited by 31 publications

References 18 publications

Reassessment of the NH4NO3 thermal decomposition technique for calibration of the N2O isotopic composition

Reassessment of the NH4NO3 thermal decomposition technique for calibration of the N2O isotopic composition

Intercomparison of real-time tailpipe ammonia measurements from vehicles tested over the new world-harmonized light-duty vehicle test cycle (WLTC)

A liquid nitrogen-free preconcentration unit for measurements of ambient N&lt;sub&gt;2&lt;/sub&gt;O isotopomers by QCLAS

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Reassessment of the NH₄NO₃ thermal decomposition technique for calibration of the N₂O isotopic composition

Reassessment of the NH₄NO₃ thermal decomposition technique for calibration of the N₂O isotopic composition

A liquid nitrogen-free preconcentration unit for measurements of ambient N<sub>2</sub>O isotopomers by QCLAS