Guidelines for Air Emission Regulation

9. Conversions regarding surplus air and moisture content

9.1 Conversion to CO2%
9.2 Conversion to reference O2%
9.3  Conversion between CO2% and O2%
9.4 Conversion between O2% and CO2%
9.5 Conversion from dry to moist volume flow
9.6 Conversion from dry to moist concentration
9.7 Conversion from ppm to mg/normal m3
9.8 Units of energy and output
9.9 Prefixes


In the following, all percentages are volume % dry gas.

9.1 Conversion to CO2%


  

Cref. = concentration at reference CO2% [mg / normal m3(ref.)]
Cmeasured = measured concentration [mg / normal m3(measured)]
CO2%(ref.) = reference CO2% [Vol%]
CO2%(measured) = measured CO2% [Vol%]


If the substance is measured at a concentration of 150 mg/normal m3 at 5% CO2, at 10% CO2 this will correspond to:

9.2 Conversion to reference O2%

Cref. = concentration at reference O2% [mg/normal m3(ref.)]
Cmeasured = measured concentration [mg/normal m3(measured)]
O2%(ref.) = reference O2% [Vol%]
O2%(measured) = measured O2% [Vol%]


If the substance is measured at a concentration of 150 mg/normal m3 at 15% O2, at 10% O2 this will correspond to:

9.3 Conversion between CO2% and O2%

9.4 Conversion between O2% and CO2%


The following values for CO2%(max) can be used (for rough calculations)

Wood and straw: 20%
Household waste: 19%
Coal: 19%
Heavy fuel oil: 16%
Light fuel oil: 15%
Natural gas: 12%

CO2%(max) gives CO2%, when combustion is without air surplus.

9.5 Conversion from dry to moist volume flow

The definition of moisture percent in the air as used in OML calculations expresses the proportion of water vapour in relation to the total volume (the volume H2O / total volume of air (including water vapour))74. Conversion between the total volume and dry volume is according to the following equation:


   
Qmoist = the total amount of moist gas [m3, moist / h]
  
Qdry = amount of dry gas [m3, dry / h]
   
H2O% = volume percentage of water vapour in relation to the total amount of moist gas [Vol%]

9.6 Conversion from dry to moist concentration


Cmoist = concentration in moist gas [mg / m3, moist]
  
Cdry = concentration in dry gas [mg / m3, dry]
  
H2O% = volume percentage of water vapour in relation to the total amount of moist gas [Vol%]

9.7 Conversion from ppm to mg/normal m3

1 ppm SO2
= 2.93 mg/normal m3 SO2 at 0oC and 101.3 kPa.
1 ppm NO
= 1.34 mg/normal m3 NO at 0oC and 101.3 kPa.
1 ppm NO2
= 2.05 mg/normal m3 NO2 at0oC and 101.3 kPa.
1 ppm CO
= 1.25 mg/normal m3 CO at 0oC and 101.3 kPa.
1 ppm CO2
= 1.98 mg/normal m3 CO2 at 0oC and 101.3 kPa.
1 ppm C
= 1.87 mg/normal m3 C at 0oC and 101.3 kPa.
1 ppm HCl
= 1.63 mg/normal m3 HCl at 0oC and 101.3 kPa.

9.8 Units of energy and output

1 J/s = 1 W
1 MJ/s = 0.8598 Gcal/h
1 kJ = 2,778 x 10-4 kWh
1 kWh = 3,600 kJ
1 kWh = 859.8 kcal
1 kcal = 1.163 x 10-3kWh
1 kcal = 4.1868 kJ

9.9 Prefixes

peta (P) 1015
tera (T) 1012
giga (G) 109
mega (M) 106
kilo (k) 103
milli (m) 10-3
micro (µ) 10-6
nano (n) 10-9
pico (p) 10-12
femto (f) 10-15
atto (a) 10-18

 

74 Moisture percentages should always be expressed as mentioned above. Certain methods of measurement (e.g. gravimetric determination of water content) allow the possibility of stating results as the amount of water vapour in relation to the dry volume of air. This result should always be converted to Vol% H2O before correction.
Recalculation from "dry" Vol% H2O to Vol% H2O:
Vol% H2O = Vol% H2O(dry) * 100 / (100 + Vol% H2O(dry)).