Gas quality parameters
The natural gas supplied and transferred at the Entry/Exit points into/from the transmission system defined in the transmission contract shall meet the following chemical and physical parameters:
a) Chemical composition
Methane (C2) | min. 92 % |
Methane (C2) | max. 4 % |
Propane (C5) | max. 2 % |
Butane (C4) | max. 1,5 % |
Pentane (C5) | max. 0,5 % |
Hexane (C6+) | max. 0,2 % |
Nitrogen (N2) | max. 2 % |
Carbon dioxide (C02) | 1 % |
Oxygen (O2) | max. 0,02% |
Hydrogen sulphide (H2S) | max. 2 mg/m3 |
Mercaptan sulphur (RSH) | max. 5,6 mg/m3 |
Total sulphur | max. 20 mg/m3 |
Gross calorific value | min. 10,80 kWh/m3max. 12,20 kWh/m3
|
Wobbe index | min. 13,59 kWh/m3 max. 15,37 kWh/m3 |
Related to normal conditions t2=15°C and p=101.325 kPa and the combustion gases temperature t1=15°C. a) Hydrocarbon dew point
Water drew pointNot higher than minus 8 degrees Celsius (-8 ˚C) at a pressure of 39.2 barg.
b) Hydrocarbon dew point
Hydrocarbon dew pointNo hydrocarbons shall condensate at a temperature of zero degrees Celsius (0 ˚C) at delivery pressure.
c) The natural Gas shall not contain any extraneous particles and mechanical impurities.