Natural gas is composed primarily of methane (typically, at least 90%), but may also contain ethane, propane and heavier hydrocarbons. Small quantities of nitrogen, oxygen, carbon dioxide, sulfur compounds, and water may also be found in “pipeline” natural gas.
The pre-treatment process removes the oxygen, carbon dioxide, sulfur compounds, and water.
The liquefaction process, compresses, cools, condenses, and lets down the pressure and temperature at which methane, the main constituent of natural gas, liquefies.
The entire process can be optimized to produce the purest form of LNG.