Abstract: Disclosed is a process for liquefying natural gas wherein an available methane-rich feed, i.e., natural gas, at an excess pressure is initially expanded to provide expansion work which may be utilized in a number of novel ways, such as to provide refrigeration in a refrigerant cycle used to cool the feed or in one or more refrigerant cycles used in a liquefaction zone to liquefy the feed, or to generate electrical power for use in the liquefaction process or for export. In one embodiment, the expansion work is obtained by use of an expander/compressor device (turboexpander) which expands the feed to (1) drive the compressor of the device and thereby provide compression for a closed loop propane refrigeration cycle to pre-cool the natural gas stream, and (2) produce an expanded, chilled natural gas feed for a liquefaction process.