Atmospheric Chemistry and Physics Discussions
www.atmos-chem-phys-discuss.net
1680-7367
1680-7375
10
2
2010
10.5194/acpd-10-3021-2010
http://www.atmos-chem-phys-discuss.net/10/3021/2010/
http://www.atmos-chem-phys-discuss.net/10/3021/2010/acpd-10-3021-2010.html
http://www.atmos-chem-phys-discuss.net/10/3021/2010/acpd-10-3021-2010.pdf
3021
3051
2010-02-05
Molecular hydrogen (H<sub>2</sub>) emissions and their isotopic signatures (H/D) from a motor vehicle: implications on atmospheric H<sub>2</sub>
M. K. Vollmer
martin.vollmer@empa.ch
S. Walter
S. W. Bond
P. Soltic
T. Röckmann
Empa, Swiss Federal Laboratories for Materials Testing and Research, Laboratory for Air Pollution and Environmental Technology, Uberlandstrasse 129, 8600 Dubendorf, Switzerland
Institute for Marine and Atmospheric research Utrecht, Utrecht University, Princetonplein 5, 3508TA Utrecht, The Netherlands
Empa, Swiss Federal Laboratories for Materials Testing and Research, Laboratory of I. C. Engines, Uberlandstrasse 129, 8600 Dubendorf, Switzerland
Molecular hydrogen (H<sub>2</sub>), its isotopic signature (deuterium/hydrogen,
δD), carbon monoxide (CO) and other compounds were studied in the
exhaust of a passenger car engine fuelled with gasoline or methane and run
under variable air-fuel ratios and operating modes. H<sub>2</sub> and CO
concentrations were largely reduced downstream of the three-way catalytic
converter (TWC) compared to levels upstream, and showed a strong dependence
on the air-fuel ratio (expressed as lambda, λ). The isotopic
composition of H<sub>2</sub> ranged from δD=–140‰ to δD=–195‰ upstream of the TWC but these values decreased to
–270‰ to –370‰ after passing through the TWC. Post-TWC
δD values for the fuel-rich range showed a strong dependence on TWC
temperature with more negative δD for lower temperatures. These
effects are attributed to a rapid temperature-dependent H-D isotope
equilibration between H<sub>2</sub> and water (H<sub>2</sub>O). In addition, post TWC
δD in H<sub>2</sub> showed a strong dependence on the fraction of removed
H<sub>2</sub>, suggesting isotopic enrichment during catalytic removal of H<sub>2</sub>
with enrichment factors (ε) ranging from –39.8‰ to
–15.5‰ depending on the operating mode. Our results imply that there
may be considerable variability in real-world δD emissions from
vehicle exhaust, which may mainly depend on TWC technology and exhaust
temperature regime. This variability is suggestive of a δD from
traffic that varies over time, by season, and by geographical location. An
earlier-derived integrated pure (end-member) δD from anthropogenic
activities of –270‰ (Rahn et al., 2002) can be explained as a mixture of
mainly vehicle emissions from cold starts and fully functional TWCs, but
enhanced δD values by >50‰ are likely for regions where TWC
technology is not fully implemented. Our results also suggest that a full
hydrogen isotope analysis on fuel and exhaust gas may greatly aid at
understanding process-level reactions in the exhaust gas, in particular in
the TWC.
Aalto, T., Lallo, M., Hatakka, J., and Laurila, T.: Atmospheric hydrogen variations and traffic emissions at an urban site in Finland, Atmos. Chem. Phys., 9, 7387–7396, 2009.
Affek, H P. and Eiler, J M.: Abundance of mass $^47$CO<sub>2</sub> in urban air, car exhaust, and human breath, Geochim. Cosmochim. Acta, 70, 1–12, \doi10.1016/j.gca.2005.08.021, 2006.
Auckenthaler, T S.: Modelling and Control of Three-Way Catalytic Converters, Ph.D. Thesis, Swiss Federal Institute of Technology, Zurich, No 16018, 2005.
Barnes, D H., Wofsy, S C., Fehlau, B P., Gottlieb, E W., Elkins, J W., Dutton, G S., and Novelli, P C.: Hydrogen in the atmosphere: Observations above a forest canopy in a polluted environment, J. Geophys. Res., 108(D6), 4197, \doi10.1029/2001JD001199, 2003.
Begemann, F. and Friedman, I.: Tritium and deuterium content of atmospheric hydrogen, Z. Naturforsch. A., 14, 1024–1031, 1959.
Bond, S W., Alvarez, R., Vollmer, M K., Steinbacher, M., Weilenmann, M., and Reimann, S.: Molecular hydrogen (H<sub>2</sub>) emissions from gasoline and diesel vehicles, Intern. J. Hydrogen Energy, in review, 2010.
Bottinga, Y.: Calculated fractionation factors for carbon and hydrogen isotope exchange in system calcite-carbon dioxide-graphite-methane-hydrogen-water vapor, Geochim. Cosmochim. Acta, 33, 49–64, 1969.
Brenninkmeijer, C. A M., Janssen, C., Kaiser, J., Röckmann, T., Rhee, T S., and Assonov, S S.: Isotope effects in the chemistry of atmospheric trace compounds, Chem. Rev., 103, 5125–5161, \doi10.1021/cr020644k, 2003.
Brühlmann, S.: Validierung H-Sense, Tech. Rep. unpublished, Empa, Swiss Federal Laboratories for Materials Testing and Research, 2004.
Chanton, J P., Rutkowski, C M., Schwartz, C C., Ward, D E., and Boring, L.: Factors influencing the stable carbon isotopic signature of methane from combustion and biomass burning, J. Geophys. Res., 105, 1867–1877, 2000.
Craig, H.: Standards for reporting concentrations of deuterium and oxygen-18 in natural waters, Science, 133, 1833–1834, 1961.
Cramer, B., Poelchau, H., Gerling, P., Lopatin, N., and Littke, R.: Methane released from groundwater: the source of natural gas accumulations in northern West Siberia, Marine and Petroleum Geology, 16, 225–244, 1999.
D'Alleva, B A. and Lovell, W G.: Relation of exhaust gas composition to air-fuel ratio, SAE Journal, 38, 90–98, 1936.
Ehhalt, D., Israel, G., Roether, W., and Stich, W.: Tritium and deuterium content of atmospheric hydrogen, J. Geophys. Res., 68, 3747–3751, 1963.
Ehhalt, D H. and Rohrer, F.: The tropospheric cycle of H<sub>2</sub>: a critical review, Tellus, Ser. B., 61, 500–535, \doi10.1111/j.1600-0889.2009.00416x, 2009.
Feilberg, K L., Johnson, M S., Bacak, A., Röckmann, T., and Nielsen, C J.: Relative tropospheric photolysis rates of HCHO and HCDO measured at the European photoreactor facility, J. Phys. Chem. A., 111, 9034–9046, \doi10.1021/jp070185x, 2007.
Friedman, I. and O'Neil, J R.: Compilation of stable isotope fractionation factors of geological interest, in: Data of Geochemistry, Geological Survey Professional Paper 440-KK, pp. KK1–KK12, 6th edn., 1977.
Gerst, S. and Quay, P.: Deuterium component of the global molecular hydrogen cycle, J. Geophys. Res., 106, 5021–5031, 2001.
Gonfiantini, R.: Standards for stable isotope measurements in natural compounds, Nature, 271, 534–536, 1978.
Gonsior, B. and Friedman, I.: Tritium and Deuterium im atmosphärischen Wasserstoff, Z. Naturforsch. A., 17, 1088–1091, 1962.
Hammer, S., Vogel, F., Kaul, M., and Levin, I.: The H<sub>2</sub>/CO ratio of emissions from combustion sources: comparison of top-down with bottom-up measurements in southwest Germany, Tellus, Ser. B., 61, 547–555, 2009.
Haryanto, A., Fernando, S D., Filip~To, S D., Steele, P H., Pordesimo, L., and Adhikari, S.: Hydrogen production through the water-gas shift reaction: Thermodynamic equilibrium versus experimental results over supported Ni catalysts, Energy $&$ Fuels, 23, 3097–3102, \doi10.1021/ef801076r, 2009.
Hauglustaine, D A. and Ehhalt, D H.: A three-dimensional model of molecular hydrogen in the troposphere, J. Geophys. Res., 107(D17), 4330, doi:10.1029/2001JD001156, 2002.
Kaiser, J., Brenninkmeijer, C. A M., and Röckmann, T.: Intramolecular $^15$N and $^18$O fractionation in the reaction of N<sub>2</sub>O with O($^1$D) and its implications for the stratospheric N<sub>2</sub>O isotope signature, J. Geophys. Res., 107, D14, \doi10.1029/2001JD001506, 2002.
Leonard, L S.: Fuel distribution by exhaust gas analysis, Society of automobile engineers, 379A, 1–22, 1961.
Nakagawa, F., Tsunogai, U., Komatsu, D D., Yamada, K., Yoshida, N., Moriizumi, J., Nagamine, K., Iida, T., and Ikebe, Y.: Automobile exhaust as a source of $^13$C- and D-enriched atmospheric methane in urban areas, Organic Geochemistry, 36, 727–738, 2005.
Novelli, P C., Lang, P M., Masarie, K A., Hurst, D F., Myers, R., and Elkins, J W.: Molecular hydrogen in the troposphere: global distribution and budget, J. Geophys. Res., 104, 30427–30444, 1999.
Pieterse, G., Krol, M. C., and Röckmann, T.: A consistent molecular hydrogen isotope chemistry scheme based on an independent bond approximation, Atmos. Chem. Phys., 9, 8503–8529, 2009.
Price, H., Jaegle, L., Rice, A., Quay, P., Novelli, P C., and Gammon, R.: Global budget of molecular hydrogen and its deuterium content: Constraints from ground station, cruise, and aircraft observations, J. Geophys. Res., 112, D22108, \doi10.1029/2006JD008152, 2007.
Rahn, T., Kitchen, N., and Eiler, J.: D/H ratios of atmospheric H<sub>2</sub> in urban air: Results using new methods for analysis of nano-molar H<sub>2</sub> samples, Geochim. Cosmochim. Acta, 66, 2475–2481, 2002.
Rahn, T., Eiler, J M., Boering, K A., Wennberg, P O., McCarthy, M C., Tyler, S., Schauffler, S., Donnelly, S., and Atlas, E.: Extreme deuterium enrichment in stratospheric hydrogen and the global atmospheric budget of H<sub>2</sub>, Nature, 424, 918–921, 2003.
Rhee, T S., Mak, J., Röckmann, T., and Brenninkmeijer, C. A M.: Continuous-flow isotope analysis of the deuterium/hydrogen ratio in atmospheric hydrogen, Rapid Commun. Mass Spectrom, 18, 299–306, 2004.
Rhee, T. S., Brenninkmeijer, C. A. M., and Röckmann, T.: The overwhelming role of soils in the global atmospheric hydrogen cycle, Atmos. Chem. Phys., 6, 1611–1625, 2006.
Röckmann, T., Rhee, T. S., and Engel, A.: Heavy hydrogen in the stratosphere, Atmos. Chem. Phys., 3, 2015–2023, 2003.
Röckmann, T., Gómez~Álvarez, C X., Walter, S., van~der Veen, C., Wollny, A G., Gunthe, S., Helas, G., Pöschl, U., Keppler, F., Greule, M., and Brand, W A.: The isotopic composition of H<sub>2</sub> from biomass burning – dependence on combustion efficiency, moisture content and δD of local precipitation, J. Geophys. Res., in review, 2010.
Salaün, M., Kouakou, A., Da~Costa, S., and Da~Costa, P.: Synthetic gas bench study of a natural gas vehicle commercial catalyst in monolithic form: On the effect of gas composition, Applied Catalysis B: Environmental, 88, 386–397, 2009.
Sanderson, M G., Collins, W J., Derwent, R G., and Johnson, C E.: Simulation of global hydrogen levels using a Lagrangian three-dimensional model, J. Atmos. Chem., 46, 15–28, 2003.
Schimmelmann, A., Sessions, A L., and Mastalerz, M.: Hydrogen isotopic (D/H) composition of organic matter during diagenesis and thermal maturation, Annual Review of Earth and Planetary Sciences, 34, 501–533, \doi10.1146/annurev.earth.34.031405.125011, 2006.
Steinbacher, M., Fischer, A., Vollmer, M K., Buchmann, B., Reimann, S., and Hueglin, C.: Perennial observations of molecular hydrogen (H<sub>2</sub>) at a suburban site in Switzerland, Atm. Environ., 41, 2111–2124, \doi10.1016/j.atmosenv.2006.10.075, 2007.
Toyoda, S., Yamamoto, S., Arai, S., Nara, H., Yoshida, N., Kashiwakura, K., and Akiyama, K.: Isotopomeric characterization of N<sub>2</sub>O produced, consumed, and emitted by automobiles, Rapid Commun. Mass Spectrom, 22, 603–612, \doi10.1002/rcm.3400, 2008.
Tsunogai, U., Hachisu, Y., Komatsu, D D., Nakagawa, F., Gamo, T., and Akiyama, K.: An updated estimation of the stable carbon and oxygen isotopic compositions of automobile CO emissions, Atm. Environ., 37, 4901–4910, \doi10.1016/j.atmosenv.2003.08.008, 2003.
Vollmer, M K., Juergens, N., Steinbacher, M., Reimann, S., Weilenmann, M., and Buchmann, B.: Road vehicle emissions of molecular hydrogen (H<sub>2</sub>) from a tunnel study, Atm. Environ., 8355–8369, \doi10.1016/j.atmosenv.2007.06.037, 2007.
Walter, S. and et~al.: Manuscript in preparation, 2010.
Xiao, X., Prinn, R G., Simmonds, P G., Steele, L P., Novelli, P C., Huang, J., Langenfelds, R L., O'Doherty, S., Krummel, P B., Fraser, P J., Porter, L W., Weiss, R F., Salameh, P., and Wang, R. H J.: Optimal estimation of the soil uptake rate of molecular hydrogen from the Advanced Global Atmospheric Gases Experiment and other measurements, J. Geophys. Res., 112, D07303, \doi10.1029/2006JD007241, 2007.