Gas composition and quality for transmission, monthly

Gas quality data for the Danish transmission grid that is representative for gas delivered from the transmission grid. The data are validated but the data cannot be used for billing purposes. The basis of the dataset is hourly values and the maximal and minimal value is therefore respective the maximal and minimal hourly value.

The values listed are for informational purposes only and are not suited for settlement purposes. Though Energinet consider the numbers to be true, we cannot guarantee the accuracy of the values.


Month

Comment
Description

Year and month

Title

Month

Property constraint
Name

Month

Validation rules
Type

date

Example

2017-01

Unit

Months

Size

7

Gas quality parameter

Description

For each month there are 20 rows with average, min. and max. values for the following gas quality parameters:

Methane, Ethane, Propane, I-butane, N-butane, I-pentane, N-pentane, Hexane+, Carbon dioxide, Nitrogen, and Oxygen. All of these are components of the natural gas and have mole % as unit.

The remaining of the 20 gas quality parameters are described in greater detail below

Gross Calorific Value: A term describing the amount of heat de-veloped by combustion of one cubic metre of gas at constant pressure when the gas and air for the combustion have a temperature of 25\u00b0C, the combustion products being brought to that temperature and the water formed by the combustion being present in liquid state. The reference conditions for normal cubic metres are 0\u00b0C and 1 atm.

Net Calorific Value: A term describing the amount of heat generated, when the temperature of the combustion air and the natural gas prior to combustion is 25\u00b0C, when the combustion products (flue gas) are cooled to 25\u00b0C, and when the water produced during combustion is present in the form of steam. The reference conditions for normal cubic metres are 0\u00b0C and 1 atm.

Wobbe Index: The Wobbe index offers information about the heating effect a burner is exposed to during combustion of a fuel. The greater the Wobbe index, the greater the heating effect and thereby the greater the load on the burner. The load on a burner is thus directly proportional to the Wobbe index. Different gases with the same Wobbe index will impose the same load on the burner. The Wobbe index can be calculated as the gross calorific value divided by the square root of the relative density.

Normal Density: Normal density is the mass of a normal cubic meter of gas. The reference conditions for normal cubic metres are 0\u00b0C and 1 atm. Relative Density: The relative density aka the specific gravity is the density of natural gas divided by the density of air at the same pressure and temperature, and is an expression of the amount of heavier hydrocarbons that are in the natural gas.

Methane Number: A methane number characterises the gas’s knock tendency as a fuel for gas engines. It can be compared to the octane number for petrol.

Water Dew Point: Water content of gas described as dew point at the absoluite pressure of 70 bar.

Hydro Carbon Dew Point: The temperature for precipitation of liquid hydro carbons measured at the pressure with the highest hydrocarbon dew point.

H2S: Hydrogen Sulphide content of the natural gas

Total Sulphur: Total Sulphur content of the un-odorized natural gas.

H2S and total sulphur are given as the measurement in Nybro.

Title

Gas quality parameter

Property constraint
Name

Qualityvalue

Validation rules
Type

string

Example

Methane

Unit

text

Size

20

Unit

Comment
Description

Unit for the gas quality values. Possible values are:

  • mole - %
  • kWh/Nm\u00b3
  • MJ/Nm\u00b3
  • kg/Nm\u00b3
  • [-]
  • \u00b0C
  • mg/Nm\u00b3
  • kg/GJ
Title

Unit

Property constraint
Format
Name

Unit

Validation rules
Type

string

Example

kWh/Nm\u00b3

Unit

text

Size

20

Gas quality average

Comment
Description

Average value for the gas quality parameters.

Title

Gas quality average

Property constraint
Format

([0-9]*[,])[0-9][0-9][0-9]

Name

Average

Validation rules
Type

number

Example

43.792

Unit

Number

Size

7.3

Min

Comment
Description

Montly minimum value for the gas quality parameters.

Title

Min

Property constraint
Format
Name

Min

Validation rules
Type

number

Example

41.609

Unit

Number

Size

7.3

Max

Comment
Description

Monthly maximum value for the gas quality parameters.

Title

Max

Property constraint
Format
Name

Max

Validation rules
Type

number

Example

44.111

Unit

Number

Size

7.3