The density of natural gas is usually expressed in kg/m3 (kilograms per cubic meter) or lb/ft3 (pounds per cubic foot). Natural gas density is customarily measured at standard conditions (STC); this includes standard temperature (0ยฐC or 32ยฐF) and standard pressure (1 atmosphere or 14.7 psia).
Natural gas has a very low density (it’s lighter than air). Namely, the density of natural gas at standard conditions ranges from 0.71 kg/m3 to as high as 0.97 kg/m3. For comparison, the air has a 1.293 kg/m3 density at the same conditions. Why do we have this wide 0.71 – 0.97 kg/m3 range?
Well, natural gas is composed of a mixture of gases (C1 to C7 hydrocarbons, to be specific). The main component is C1 gas methane (chemical formula: CH4). C1, C2, C3 gases like methane have lower weight than C4, C5, C6, and C7 gases like pentane. If natural gas has a higher percentage of higher C gases, the density is closer to 0.97 kg/m3. If natural gas has a higher percentage of lower C gases, the density is closer to 0.71 kg/m3.
Here are average, low, and high natural gas densities in a chart (expressed in kg/m3 and lb/ft3):
Density Of Natural Gas Chart
| kg/m3: | lb/ft3: | |
|---|---|---|
| Average-Density Natural Gas: | 0.84 kg/m3 | 0.052 lb/ft3 |
| Low-Density Natural Gas: | 0.71 kg/m3 | 0.044 lb/ft3 |
| High-Density Natural Gas: | 0.97 kg/m3 | 0.061 lb/ft3 |
Let’s spell these numbers out to get a good realistic grip on what is the weight of average-density natural gas per standard cubic meter or standard cubic foot:
- 1 standard cubic meter of natural gas weighs 0.84 kg.
- 1 standard cubic foot of natural gas weighs only 0.052 lbs. In the US, we pay natural gas by thousand cubic feet or MCF (gas price is about $15 per MCF). In the winter (heating), an average US household uses about 10 MCF per month (that’s 520 lbs of gas). In the summer, the average monthly use drops to about 2-3 MCF (that’s about 100-150 lbs of gas).
- To get 1 kg of natural gas, we need 1.19 m3 of average-density natural gas.
- To get 1 pound of natural gas, we need almost 20 cubic feet of gas (19.23 ft3, to be exact).
We hope that now you have a good grip on what is the density of natural gas, both low-density and high-density, as well as average-density. If you have any questions or would need some help, our comment section below is always open, just ask a question, and we can help you out.