Abstract: The fuel required to provide the energy for compressing a gas can be reduced by compressing the gas substantially adiabatically through a pressure ratio of at least 2.5:1 in a compressor, cooling the hot compressed gas by heat exchange with water at superatmospheric pressure, further heating the water to produce super-heated steam and using the superheated steam to drive the compressor. The total amount of fuel consumed can be considerably less than that used for compressing gas conventionally (i.e. substantially isothermally).

Abstract: A method for cooling and liquefying a methane-rich gas stream, such as natural gas, is set forth wherein the methane-rich gas stream is heat exchanged against a single component refrigerant, such as propane, in a closed cycle and a multicomponent refrigerant, such as lower hydrocarbons, in another closed cycle in which the single component refrigerant is used to cool the multicomponent refrigerant subsequent to the multicomponent refrigerant's compression and between stages of its compression. The additional cooling between stages of compression shifts compression load from the multicomponent refrigeration cycle to the single component refrigeration cycle. This shift of compression load allows the load on the compression drivers on both cycles to be balanced. The ability to shift compression load is beneficial in cool ambient condition regions where the two cycles could be effected differentially.