Air pollution calculations part I

I am chemical engineer who is involved in water pollutions and air pollutions. Actually I am closely familiar with air pollutions and some of the methods of they calculation. Recently I have invited in a phone interview about my abilities in emission engineering. The people who lead the interview ask about some of the principles of calculating pollution of SO2 and NOx.
I had prepared my self before but may be not enough and two weeks ago they didn’t invite me to the face to face interview. But this is not the basis of this my post.
In this post I want to take a look about two methods of calculation of pollutions. At first I will describe the stoichiometric method which is based on the calculations of molecular masses of the each element in the chimney gasses. The second method is named Corinair from the CORe INventory of AIR Emissions. This methodology is developed from the then European Topic Centre on Air Emissions under contract to the European Environment Agency.
At first we should see what are the limitations in EU about some pollution compounds such as Sulfur Dioxide. The Directive 2001/80 describe those emission limits and give the specific differences between appliances depend from them heat power.
The Sulfur dioxide has a linear decrease chart where you could calculate the limit. This is only for liquid fuels and with 3% oxygen content burning of course and there is the chart:




As you see here the limit of SO2 emissions is 1700 mg SO2 per normal cubic meter if your combustion plant has less than 300 MWt heating power. From 300 to 500 we have linear decreasing from 1700 down to 400 mg/Nm3. And for big combustion plants we have 400 mg/Nm3 for limit of SO2.
If the fuel is a gaseous fuel at general (it means natural gases not this which could be received in some refineries from different types of cracking processes) the limit of SO2 is 35 mg/Nm3.
For NOx the limits are quite different.


So every of this info about limits you are able to see here.