N2O calculation

[Kam999]

Can any body direct me how to calcualte N2O emission from the combustion of fossil fuels.
N2O is one of the Green House Gases.
Fuels we are using are
Coke
Gas Oil
Diesel
Kero
Natural Gas
Refinery Gas

Thanks.

Muhammad Ehtisham

 

[PeterAB]

Sorry there is no quick answer to this one. Its not just a matter of what you are burning. Combustion conditions, esp. temperature, are important.

 

[vintage70]

and excess oxygen too

 

[mohtogh]

I think you mean NO2 (not N2O) , and also depends on pressure .

 

You may need to check US EPA publication called Emission factor AP-42. web site:

http://www.epa.gov/ttn/chief/ap42/

for external and internal combustion sources.

 

[7604]

well you have to take samples of the combustion product analyse the with GC and make the material balances- simple

 

[ideahamster]

Ehti, as mentioned by 7604, we have found the easiest method is to measure the offgas. I don't what type of abatement device you are talking about and how many stages of combustion it contains and I am also wondering if you are talking about NOx (NO + NO2) as opposed to N2O. Assuming the former, we have employed three different methods - we have had a certified offgas abatement company take samples of the stack under different operating conditions both in the Oxidizer as well as in the process which is sending the offgas to the Oxidizer. We then regressed the data into a fairly simple equation which can be used for ongoing predictions. The second method: We had a unit shut down on our site and they had an Enerac 3000 which is a portable probe sampling device. We permanently borrowed this device and we use it periodically to ensure our algorithm is still tight. Third: we have an online NOx analyzer in our stack. We have had problems with tubing leaks and moisture so we haven't found this to be completely reliable at this point.
Keep in mind that, as PeterAB pointed out, the resulting concentration is a combination of the incoming N bearing compounds, the temperature of the vessel, the O2 level (in general, you want a reducing zone followed by an oxidizing zone), all of which is very complex in terms of predicting resulting NOx levels.
Having said all of this, if you are really looking for N2O, then I have no experience with this and you can disregard all of the above.

Thanks,
Tim

 

[25362]

What I remember of N2O (nitrous oxide) is that it is named "laughing gas" and is used as "propellant" gas in whipped creams and as anesthetic in dentistry.

 

[Acajun]

Also the main concern as a greenhouse gas contributor is the agriculture industry, the reason being that they use N based fertilizers and that the Nitrogen reacts with the bacteria in the soil to produce N2O. I have come across some reports that Nitric Acid plants also cause N2O to be released into the environment.

Jp

 

[25362]

Digging into technical literature I learnt that the only two nitrogen oxides considered NOx air pollutants are nitrogen dioxide NO2 and nitric oxide NO.
On measuring, both are exprssed as NO2. The later is the only gaseous pollutant with colour: it is the brownish component of the smog layer. Its residence time in the atmosphere is a few days. The natural background average concentration is 5 micrograms/cubm. Urban areas may reach values 30 times as high. NO2 is paramagnetic and is in equilibrium with its dimer N2O4, colourless and diamagnetic.

NOx mixes consist mostly of NO that is released on high-temperature combustion of fossil fuels in power plants and in internal combustion engines. Other sources are fertilizers, gas plants where natural gas is used as turbine fuel for compressors and gas pipelines. NO reacts readily with oxygen to form NO2. At high pressures it disproportionates into N2O + NO2.

N2O is mostly prepared by thermal decomposition of ammonium nitrate.