A liquefied natural gas production system, the system comprising: a natural gas stream from a supply of natural gas ; a refrigerant stream from a refrigerant supply ; at least one heat exchanger that exchanges heat between the refrigerant stream and the natural gas stream and that comprises a first heat exchanger to at least partially vaporize the refrigerant stream and at least partially condense the natural gas stream; a natural gas compressor that compresses the natural gas stream to a pressure of at least 135 bara to form a compressed natural gas stream; a natural gas cooler that cools the compressed natural gas stream after being compressed by the natural gas compressor, wherein the natural gas cooler is configured to cool the compressed natural gas stream to near ambient temperature; and a natural gas expander that expands the compressed natural gas to a pressure less than 200 bara, but no greater than the pressure to which the natural gas compressor compresses the natural gas stream, after being cooled by the natural gas cooler; wherein the natural gas expander is connected to the first heat exchanger to supply natural gas thereto, with the liquefied natural gas production system being characterized in that the at least one heat exchanger further comprising a second heat exchanger that cools the natural gas stream prior to the natural gas stream being compressed in the natural gas compressor ; or the compressed natural gas stream prior to the compressed natural gas stream being cooled in the natural gas cooler , wherein the refrigerant stream comprises a liquefied nitrogen stream, and wherein the at least one heat exchanger at least partially vaporizes the nitrogen stream. a natural gas stream from a supply of natural gas ; a refrigerant stream from a refrigerant supply ; at least one heat exchanger that exchanges heat between the refrigerant stream and the natural gas stream and that comprises a first heat exchanger to at least partially vaporize the refrigerant stream and at least partially condense the natural gas stream; a natural gas compressor that compresses the natural gas stream to a pressure of at least 135 bara to form a compressed natural gas stream; a natural gas cooler that cools the compressed natural gas stream after being compressed by the natural gas compressor, wherein the natural gas cooler is configured to cool the compressed natural gas stream to near ambient temperature; and a natural gas expander that expands the compressed natural gas to a pressure less than 200 bara, but no greater than the pressure to which the natural gas compressor compresses the natural gas stream, after being cooled by the natural gas cooler; wherein the natural gas expander is connected to the first heat exchanger to supply natural gas thereto, with the liquefied natural gas production system being characterized in that wherein the natural gas expander is connected to the first heat exchanger to supply natural gas thereto, with the liquefied natural gas production system being characterized in that the at least one heat exchanger further comprising a second heat exchanger that cools the natural gas stream prior to the natural gas stream being compressed in the natural gas compressor ; or the compressed natural gas stream prior to the compressed natural gas stream being cooled in the natural gas cooler , wherein the refrigerant stream comprises a liquefied nitrogen stream, and wherein the at least one heat exchanger at least partially vaporizes the nitrogen stream. <EOS>