Substitute natural gas (SNG), or synthetic natural gas, is a fuel gas (predominantly methane, CH4) that can be produced from fossil fuels such as lignite coal, oil shale, or from biofuels (when it is named bio-SNG) or using electricity with power-to-gas systems.
So we’ve got “gas” in the US (short for “gasoline”), which is a liquid. There’s liquified petroleum gas (LPG), which is also a liquid. And there’s synthetic natural gas.
EDIT: Bonus: my understanding is that in Germany, an unqualified “gas” tends to refer to natural gas, which Germany is presently importing in liquid form (liquified natural gas, or LNG).
https://en.wikipedia.org/wiki/Substitute_natural_gas
So we’ve got “gas” in the US (short for “gasoline”), which is a liquid. There’s liquified petroleum gas (LPG), which is also a liquid. And there’s synthetic natural gas.
EDIT: Bonus: my understanding is that in Germany, an unqualified “gas” tends to refer to natural gas, which Germany is presently importing in liquid form (liquified natural gas, or LNG).