Normalgas

Normalgas is a hypothetical gaseous energy carrier used in energy modeling and academic literature to represent a baseline natural gas mixture. As a modeling construct, it provides a standard reference composition against which alternative fuels and process configurations can be compared. Because it is not a real substance, its exact formulation varies by study, but it is typically methane-dominated and designed to resemble conventional natural gas within common pipeline and combustion standards.

In most definitions, Normalgas contains roughly 60–90% methane, with ethane, propane, and heavier hydrocarbons in smaller shares, plus carbon dioxide and nitrogen as inert components. The precise Wobbe index, heating value, and molar composition are left to the modeling assumptions. The gas is assumed to be colorless, odorless, and flammable for simulation purposes, with properties that can be adjusted to reflect different supply regions.

As a concept, Normalgas is not produced or traded physically. It is generated digitally in datasets or software to calibrate models of pipelines, engines, and gas-fired systems. Researchers may define multiple Normalgas variants to study sensitivity to composition.

It is used in optimization of energy systems, reliability planning for gas networks, emissions accounting, and comparative analysis of fuels in combustion simulations.

Properties mirror those of real methane-rich gases, so safety and environmental concerns entail flammability and methane emissions; the utility of Normalgas is to isolate the effects of gas composition from other variables.

The term appears in modeling literature from the late 20th century onward as a convenient referent for a standard gas.

See also: Natural gas, Gas mixture, Energy modeling.