Gas quality requirements

Gas quality requirements for the injection of biomethane and gaseous LNG into the Latvian gas transmission system (published in accordance with paragraph 11 of the Regulation of the Cabinet of Ministers No. 567 of September 13, 2022).

No.	Indicators	Unit	Value
1.	Wobbe number (index), W_S	kWh/m³	14,02 – 15,5 *
2.	Combustion heat (inferior)	kWh/m³	≥ 10.41 *
3.	Combustion heat (superior)	kWh/m³	≥ 9.48 *
4.	Relative density, d	No unit	0,55 – 0,7
5.	Total Sulphur, S	g/ m³	≤ 0,03
6.	Hydrogen sulphide + carbon sulphide, H2S+COS (as S)	g/ m³	≤ 0,007
7.	Mercaptans, RSH (as S)	g/ m³	≤ 0,016
8.	Methane, CH₄	mol, %	≥ 90
9.	Nitrogen, N₂	mol, %	≤ 3
10.	Oxygen, O₂	mol, %	≤ 0,02/(0,5)**
11.	Carbon dioxide, CO₂	mol, %	≤ 2,5
12.	Water dew point, H₂O DP	°C, at 4,0 MPa	≤ -10
13.	Hydrocarbon dew point, HC DP	°C, at 0,1-7,0 MPa	≤ -2
14.	Mechanical impurities	g/ m³	≤ 0,001
15.	Methane number	no unit	≥ 65
16.	Hydrogen, H₂	mol, %	≤ 0,1/(2)**
17.	Liquid phase of water and hydrocarbons	g/m³	Not permissible

* The reference conditions for these parameters have been indicated in base temperature conditions (combustion/measuring) 25/0°C, pressure 101.325 kPa

** gas quality requirements may deviate up to the value indicated in the brackets due to connected biomethane or hydrogen producers.