A process for liquefying a hydrocarbon feed gas comprising the steps of: a) pre-treating the hydrocarbon feed gas to remove sour species and water therefrom; b) providing a refrigeration zone, wherein refrigeration in the refrigeration zone is provided by circulating a mixed refrigerant from a mixed refrigerant system and an auxiliary refrigerant from an auxiliary refrigeration system through the refrigeration zone; c) coupling the mixed refrigerant system and the auxiliary refrigeration system in a manner whereby the auxiliary refrigeration system is driven, at least in part, by waste heat generated by the mixed refrigerant; and d) passing the pre-treated feed gas through the refrigeration zone where the pre-treated feed gas is cooled and expanding the cooled feed gas to produce a hydrocarbon liquid, characterized in that the step of circulating a mixed refrigerant through the refrigeration zone comprises: i) compressing the mixed refrigerant in a compressor; ii) passing the compressed mixed refrigerant through a first heat exchange pathway extending through the refrigeration zone where the compressed mixed refrigerant is cooled and expanded to produce a mixed refrigerant coolant; iii) passing the mixed refrigerant coolant through a second heat exchange pathway extending through the refrigeration zone to produce a mixed refrigerant; and iv) recirculating the mixed refrigerant to the compressor that the process further comprises the waste heat is produced from a gas turbine driving the compressor in the compressing step, and that the waste heat is utilized to produce steam in a single steam turbine generator that is configured to produce electrical power which drives auxiliary refrigeration compressors, and that the auxiliary refrigerant system comprises one or more ammonia refrigeration packages. a) pre-treating the hydrocarbon feed gas to remove sour species and water therefrom; b) providing a refrigeration zone, wherein refrigeration in the refrigeration zone is provided by circulating a mixed refrigerant from a mixed refrigerant system and an auxiliary refrigerant from an auxiliary refrigeration system through the refrigeration zone; c) coupling the mixed refrigerant system and the auxiliary refrigeration system in a manner whereby the auxiliary refrigeration system is driven, at least in part, by waste heat generated by the mixed refrigerant; and d) passing the pre-treated feed gas through the refrigeration zone where the pre-treated feed gas is cooled and expanding the cooled feed gas to produce a hydrocarbon liquid, characterized in that the step of circulating a mixed refrigerant through the refrigeration zone comprises: i) compressing the mixed refrigerant in a compressor; ii) passing the compressed mixed refrigerant through a first heat exchange pathway extending through the refrigeration zone where the compressed mixed refrigerant is cooled and expanded to produce a mixed refrigerant coolant; iii) passing the mixed refrigerant coolant through a second heat exchange pathway extending through the refrigeration zone to produce a mixed refrigerant; and iv) recirculating the mixed refrigerant to the compressor i) compressing the mixed refrigerant in a compressor; ii) passing the compressed mixed refrigerant through a first heat exchange pathway extending through the refrigeration zone where the compressed mixed refrigerant is cooled and expanded to produce a mixed refrigerant coolant; iii) passing the mixed refrigerant coolant through a second heat exchange pathway extending through the refrigeration zone to produce a mixed refrigerant; and iv) recirculating the mixed refrigerant to the compressor