Abstract: An incoming compressed gas, such as natural gas, is pre-cooled and the gas separated from any included liquid. The pre-cooled and separated gas is expanded using an expander to rapidly reduce pressure and corresponding temperature, as well as remove any components solidified by the temperature drop. An output stream from the expander, combined with other streams, is again gas/liquid separated. The output separated gas stream is sent through another expansion and gas/liquid separation, separating one or more other components, such that a final output gas is achieved. In the case of natural gas, the final output is, for example, methane, which may be fed back to cool the incoming gas prior to end use of the methane.