Natural gas production contains low molecular weight hydrocarbon compounds; it include methane (CH4), ethane (C2H6), propane (C3H8) and butane (C4H10). Although these hydrocarbons exist in a liquid state at underground pressures, they will become gaseous at normal atmospheric pressure, they are called natural gas liquids (NGLs). In the plant, contaminants are removed and the NGL hydrocarbons are recovered for other commercial uses. For economic reasons, some plants may be designed to yield an intermediate product typically containing over 90 per cent pure methane and smaller amounts of CO2,...