Modelling Methane Emission

Arah JRM, Kirk GJD. 2000. Modeling rice plant-mediated methane emission. Nutrient Cycling in Agroecosystems 58 221-230. 

Knox JW, Matthews RB, Wassmann R. 2000. Using a crop/soil simulation model and GIS techniques to assess methane emissions from rice fields in Asia. III. Databases. Nutrient Cycling in Agroecosystems 58 179-199. 

A variety of process-based models of methane emission from wetlands have been published, ranging from very complex models requiring a large number of measured input parameters to straightforward special-purpose models involving correlations between measured parameters. These models have been developed to understand controls on CH4 fluxes from a range of environments, as well as to scale fluxes and soil consumption to global scales. 

Cao M., Marshall S., and Gregson K. (1996) Global carbon exchange and methane emissions from natural wetlands application of a process-based model. J. Geophys. Res. 101, 14399-14414. 

Walter B. and Heimann M. (2000) A process-based, climate-sensitive model to derive methane emissions from natural wetlands application to five wetland sites, sensitivity to model parameters, and climate. Global Biogeochem. Cycles 14, 745-765. 

Walter B. P., Heimann M., and Matthews E. (2001) Modeling modern methane emissions from natural wetlands 1. Model description and results. J. Geophys. Res.-Atmos. 106, 34189-34206. 

IPCC) model. According to this model, GHG emission is reported in carbon dioxide equivalent unit. This is a quantity that describes for a given mixture and amount of GHG the amount of COj that would have the same GWP when measured over a specified timescale (generally, 100 years). The CO2 equivalent of methane emission is 25 according to this model. This is the characterization factor for methane, which means 1 kg of methane emission will have the same GWP impact as 25 kg of CO2. 

Methanotrophic microorganisms play a very important role in landfills. Microbial oxidation of methane in the upper layers of waste and landfill biocovers leads to a reduction of methane emissions from landfills by at least 25-30% per year (Nozhevnikova et al. 1993 Chanton Liptay, 2000). The analysis of data on 42 landfills shows that the removal efficiency of methane in landfill biocovers is from 22% in clayey materials to 55%, in sandy materials. The overall mean value across all the studies was 36% 6%, while the range of annual fluctuations observed in the 15 landfills was from 11% to 89% (Chanton et al. 2009). In practice, the share of methanotrophs in the reduction of methane emissions from landfills is much larger than 10% which is assumed in the models of methane emissions. 

She received her M.Sc. of the philosophy of nature and the protection of the environment at the Catholic University of Lublin in 1993. In 1999 she received her Ph.D. in agrophysics after defence the thesis entitled A possibility of the reduction of methane emission form landfill by its biochemical oxidation in landfill cover—model study , at the Institute of Agrophysics of the Polish Academy of Science. 

Kebreab E, K. A. Johnson, S. L. Archibeque, D. Pape and T. Wirth, 2008. Model for estimating enteric methane emissions from United States dairy and feedlot cattle. J Anim Sci. 86, 2738-2748. 

The temperature for methane and butane calculated with the isothermal model is a factor 1.4 times greater than the average temperature measured by Lihou and Maund (1982) in their small-scale tests, although higher local maximum temperatures were measured. In this model, combustion is stoichiometric, thus leading to very high fireball temperatures which, in turn, lead to high radiation emissions. Effective surface emissions measured experimentally were one-half the value calculated from this model, because combustion is not stoichiometric and emissivity is less than unity. 

Many extensive models of the high-temperature oxidation process of methane have been published [20, 20a, 20b, 21], Such models are quite complex and include hundreds of reactions. The availability of sophisticated computers and computer programs such as those described in Appendix I permits the development of these models, which can be used to predict flow-reactor results, flame speeds, emissions, etc., and to compare these predictions with appropriate experimental data. Differences between model and experiment are used to modify the mechanisms and rate constants that are not firmly established. The purpose here is to point out the dominant reaction steps in these complex... 

Both the modeling studies and smog-chamber simulations show significant oxidant formation with NO -h aldehydes, NO, + alkanes (except methane), or even NO, -i- carbon monoxide in moist air. The development of significant oxidant from NO + aldehydes is particularly ominous, because aldehyde emission is not now controlled. As the modelers state [Pg.27]

We have coupled ECHAM to a tropospheric chemistry model that considers tropospheric chemistry including non-methane hydrocarbons (NMHC) which are represented in the Carbon Bond Model (CBM-4). The model considers emissions of NO, CO and NMHC, dry deposition of 03, N02, HN03 and H202, and wet deposition of HN03 and H202. Surface CH, concentrations are prescribed. A version of the chemistry model without... 

Table 3. Base background scenarios and subsonic aircraft NOx scenarios used in the global model studies. These scenarios are used to study ozone increases, non linearity in ozone productions from aircraft emissions and the impact on methane lifetime and methane concentrations for future aircraft emissions.

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