Greenhouse nitrous oxide

Excess fertilizer and combustion processes also can increase nitrous oxide (NnO) and nitrogen oxides (NOx) in the atmosphere. Nitrous oxide is a powerful greenhouse gas, and nitrogen oxides lead to smog and acid rain. The production of fertilizers requires a great deal of energy. The use of fossil fuels to supply the thermal requirements for fertilizer production further increases emission of nitrogen compounds to the atmosphere. 

Nitrous oxide has received increasing attention the last decade, due to the growing awareness of its impact on the environment, as it has been identified as an ozone depletion agent and as a Greenhouse gas [1]. Identified major sources include adipic acid production, nitric acid and fertilizer plants, fossil fuel and biomass combustion and de-NOx treatment techniques, like three-way catalysis and selective catalytic reduction [2,3]. 

Since nitrous oxide, NjO, is a designated "greenhouse" gas, and may contribute to depletion of the ozone layer, its removal from emissions to atmosphere is desirable [1]. However, there are several reports that NjO can be formed at low selectivity as an undesirable by-product of NO+CO conversions during the initial warm-up-from-cold periods in three-way-catalytic (TWC) converters or components thereof [1-3]. TWC s commonly contain Rhodium and Ceria and although N,0 dissociation over RhjO, has been extensively studied [4], the following are among mechanistic possibilities as yet... 

Chianese, D. S., Rotz, C. A., and Richard, T. L. (2009d). Simulation of nitrous oxide emissions from dairy farms to assess greenhouse gas reduction strategies. Trans. ASABE 52, 1325-1335. 

Some greenhouse gases occur naturally in the atmosphere, while others result from human activities. Naturally occurring greenhouse gases include water vapor, carbon dioxide, methane, nitrous oxide, and ozone. Certain human activities, however, add to the levels of most of these naturally occurring gases ... 

Each greenhouse gas differs in its ability to absorb heat in the atmosphere. HFCs and PFCs are the most heat-absorbent. Methane traps over 21 times more heat per molecule than carbon dioxide, and nitrous oxide absorbs 270 times more heat per molecule than carbon dioxide. Often, estimates of greenhouse gas emissions are presented in units of millions of metric tons of carbon equivalents (MMTCE), which weighs each gas by its GWP value, that is, Global Warming Potential. 

Problems may arise when the atmospheric concentration of greenhouse gases increases. Since the beginning of the industrial revolution, atmospheric concentrations of carbon dioxide have increased nearly 30%, methane concentrations have more than doubled, and nitrous oxide concentrations have risen by about 15%. These increases have enhanced the heat-trapping capability of the earth s atmosphere. 

What has changed in the last few hundred years is the additional release of carbon dioxide by human activities. Fossil fuels burned to run cars and trucks, heat homes and businesses, and power factories are responsible for about 98% of carbon dioxide emissions, 24% of methane emissions, and 18% of nitrous oxide emissions. Increased agriculture, deforestation, landfills, industrial production, and mining also contribute a significant share of emissions (5). For example, in 1997, the United States emitted about one-fifth of total global greenhouse gases. 

Much later—more than half a century after Carothers invented nylon— scientists at the University of California at San Diego discovered that the production of nylon seemed to contribute a small but significant amount of nitrous oxide to the atmosphere. By that time, it was well known that nitrous oxide, N20, is a potent greenhouse gas and ozone destroyer. Within a month of the discovery s publication in 1991, Du Pont and several other nylon producers announced plans to phase out nitrous oxide emissions within five years. 

Energy production and consumption pose nature into pressure and make the energy sector becomes the largest contributor of greenhouse gas (GHG) emission in Vietnam since 2010, accounting for 67%. Several emission sources of GHG could be found in a waste treatment facilities it came from (1) emission of methane (CH4, GWP 25) at landfill of mixed waste, (2) from emission of fossil carbon dioxide through the combustion of plastics and composites or supported fuels (auxiliary), and (3) from emission of nitrous oxide (NOx) during incineration/ pretreatment process, etc. 

Fig. 4.1 Greenhouse gas emission such as carbon dioxide (C02), methane (CH4) and nitrous oxide (N20) converted to C02 equivalents, by sector in 2004 (Barker et al. 2007). Agriculture and forestry together play a major role in the global fluxes of the greenhouse gases carbon dioxide, nitrous oxide and methane...

Fig. 4.2 Main sources of greenhouse gas emissions in the agricultural sector in 2005 (Smith et al. 2007). Soil emission and enteric fermentation are the main sources and agriculture is assumed to be one of the major sources particularly of nitrous oxide (N20) and methane (CH4)...

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