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SNGN Description
System Balancing
Balancing Rules
Balancing Actions
Forecasting Party
Available Capacities
Capacity Allocation
Oversubscription & Buyback
Gas Characteristics
Natural Gas
Sulphur Compounds

Gas Characteristics

Natural gas is comprised of a mixture of gases, being methane (CH4) predominant, usually in a concentration of about 90%. The characteristics of natural gas are related to the concentration of its components, which must fall within specific tolerances established by regulation.
These tolerances are defined by a series of requisites, mainly:

  • The amount of energy inherent to a specific volume, Gross Calorific Value (GCV), which converts the metered volumes into energy supplied.

  • The adequacy of a combustible gas to a burning apparatus, defined by the Wobbe Index (WI) and the Specific Gravity (d).

  • The limitation of components whose excessive amount present may deteriorate equipment used in gas transport and processing, namely water concentration (dew point), hydrogen sulfide (H2S) and sulfur.

  • Other components which may influence the security and usage of natural gas.

The quality of natural gas transported and delivered by the RNTGN is controlled by real-time monitoring of the most relevant quality parameters (GCV, gravity, Wobbe Index and gas composition) through gas and sulfur chromatographs installed at specific points of the transmission network.