Gasskvalitet

Gasskvalitet refers to the properties of gas, most commonly natural gas, that determine whether it can be safely transported through gas networks, used in households and industry, and measured accurately. A consistent gas quality is essential for interoperability between suppliers, pipelines, metering systems, and end-use appliances.

The central concept is the Wobbe-index, which relates the energy content of gas to its flow under fixed pressure. The Wobbe-index, together with other properties, affects burner performance, flame stability, and energy delivered to equipment. Related parameters include the calorific value (energy content per volume), relative density, and the gas composition.

Gas composition typically includes methane as the main component, with varying amounts of other hydrocarbons (ethane, propane, etc.), inert gases such as nitrogen, and carbon dioxide. Contaminants like hydrogen sulfide (H2S) and water vapor are controlled for safety and corrosion reasons. The gas is also required to meet dew-point specifications to prevent condensation and hydrate formation in pipelines. Odorants are often added for leak detection, though odorization is separate from quality specs.

Standards and limits for gas quality are defined by national and regional authorities and by pipeline operators. Standards cover acceptable ranges for Wobbe-index, calorific value, H2S, CO2, moisture, and other impurities, as well as measurement methods. Gas quality management involves testing at production, processing, and entry points to networks, with adjustments needed if blends of renewable gases (such as biomethane or hydrogen) are introduced, as these can alter Wobbe-index and dew points and require compatibility checks across equipment and infrastructure.