srandomat: Opet střílíš od boku a vedle:
"The gas extracted from underground hydrocarbon deposits contains a varying
mix of hydrocarbon components, which usually includes mostly methane, along with
ethane, propane and butane. Other gases also occur in natural gas, notably CO2.
These gases have wide-ranging boiling points and also different heating values,
allowing different routes to commercialization and also different uses. The
"acidic" elements such as hydrogen sulphide and carbon dioxide, together with
oil, mud, water, and mercury, are removed from
the gas to deliver a clean sweetened stream of gas. Failure to remove much or
all of such acidic molecules, mercury, and other impurities could result in
damage to the equipment. Corrosion of steel pipes and amalgamization of mercury
to aluminum within cryogenic heat exchangers could cause expensive damage".
https://en.wikipedia.org/wiki/Liquefied_natural_gas
Jinými slovy, zemní plyn musí byt před zkapalněním od siry a
uhlicitanu vyčisten, aby nekorodoval
plant equipment a zasobniky.