Requirements concerning the quality of natural gas for transmission
Specification | Unit of measure | System | ||
natural gas grade E | natural gas grade Lw | natural gas grade Ls | ||
gross calorific value | MJ/m3 | ≥ 34.1 | ≥ 30.1 | ≥ 26.1 |
net calorific value | MJ/m3 | ≥ 31.0 | ≥ 27.0 | ≥ 24.0 |
upper Wobbe index |
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- nominal | MJ/m3 | 50.0 | 41.5 | 35.0 |
- variation range | MJ/m3 | 45.0-54.0 | 37.5-45.0 | 32.5-37.5 |
hydrogen sulphide | mg/m3 | ≤ 7.0 | ≤ 7.0 | ≤ 7.0 |
oxygen | % (mole/mole) | ≤ 0.2 | ≤ 0.2 | ≤ 0.2 |
carbon dioxide | % (mole/mole) | ≤ 3.0 | ≤ 3.0 | ≤ 3.0 |
mercury vapours | µg/m3 | ≤ 30.0 | ≤ 30.0 | ≤ 30.0 |
water dew point at 5.5 MPa between 1 April and 30 September | ºC | ≤ +3.7 | ≤ +3.7 | ≤ +3.7 |
water dew point at 5.5 MPa between 1 October and 31 March | ºC | ≤ -5.0 | ≤ -5.0 | ≤ -5.0 |
hydrocarbon dew point | ºC | 0 | 0 | 0 |
hydrocarbons that may undergo condensation at temperature of 5ºC at the pipeline pressure | mg/m3 | ≤ 30.0 | ≤ 30.0 | ≤ 30.0 |
dust particles with diameter exceeding 5 µm | mg/m3 | ≤ 1.0 | ≤ 1.0 | ≤ 1.0 |
mercaptan sulphur | mg/m3 | ≤ 16.0 | ≤ 16.0 | ≤ 16.0 |
total sulphur | mg/m3 | ≤ 40.0 | ≤ 40.0 | ≤ 40.0 |
The values in the table refer to normal conditions, i.e.:
- pressure at atmospheric pressure – 101.325 kPa
- temperature – 273,15 K (0ºC)