3 replies to this topic

[Ankit_Kumar]

Hi there. 

I have NOx emission value in ppm but i want to convert it into ng/J as environmental agency limit is in ng/J.

I have calculated Stack gas flow (kg/hr) by assuming complete combustion, Molecular Wt of Fuel Gas and stack is also calculated.

Requested to kindly verify the calculations and unit used.

I have calculated Heat Input (J/hr) = LCV of Fuel (KCal/Nm3) * Vol. flow rate of Fuel gas(Nm3/hr)* 4186 

Now i am confused regarding conversion of NOx in ppm to ng/ hr ... this is wht i did:

NOx (ppm) * Vol flow of Fuel (m3/hr) = NOx (mg/hr) .... Kindly note tht Vol flow unit are not Nm3/hr but m3/hr was used.

Then NOx (mg/hr) * 1000000 = NOx (ng/hr)

So Finally, NOx (ng/J) = NOx (ng/hr) / Heat Input (J/hr) 

Regards

[Chemitofreak]

Ankit,

 

Please note the following

 

ppm wt = mg/kg

 

ppm vol = ml/m3

 

when the density is 1000 kg/m3 then only 1 ppm = 1 mg/l

[Ankit_Kumar]

I think ppm vol = ml/m3 is for liquid only.

 

For gas(air pollutant)  ppm vol= mg/m3

correct me if i m wrong ......

[Chemitofreak]

It is ppm i.e. parts per million.

 

It does't matter it is gas or liquid.

 

ppm wt = mg/kg

 

ppm vol = ml/m3

 

So use the aforementioned, and calculate.

 

If you want the change the numerator in terms of mass or volume you would require density of the fluid.