Configurations and methods for small scale lng production

An LNG plant comprising:

• a cold box comprising a heat exchanger, wherein the heat exchanger comprises a plurality of heat exchanger passes;
• a refrigeration unit fluidly coupled with the plurality of heat exchanger passes, wherein the refrigeration unit is configured to provide:
• a first refrigerant stream to a first heat exchanger pass of the plurality of heat exchanger passes, wherein the first refrigerant stream is at a first pressure;
• a second refrigerant stream to a second heat exchanger pass of the plurality of heat exchanger passes, wherein the second refrigerant stream comprises a first portion of the first refrigerant stream downstream of the first heat exchanger pass, and wherein the second refrigerant stream is at a second pressure;
• and
• a third refrigerant stream to a third heat exchanger pass of the plurality of heat exchanger passes, wherein the third refrigerant stream comprises a second portion of the first refrigerant stream downstream of the first heat exchanger pass, and wherein the third refrigerant stream is at a third pressure, wherein the second pressure and the third pressure are both below the first pressure,
• wherein the cold box is configured to receive a natural gas feed stream and produce LNG from the natural gas feed stream using a refrigeration content from the refrigeration unit in the plurality of heat exchanger passes.

A method of generating LNG from a natural gas feed comprising:

• passing a first refrigerant stream through a first heat exchanger pass of a plurality of heat exchanger passes in a cold box, wherein the first refrigerant stream is at a first pressure;
• separating the first refrigerant stream into a second refrigerant stream and a third refrigerant stream downstream of the cold box;
• passing the second refrigerant stream through a second heat exchanger pass of the plurality of heat exchanger passes, wherein the second refrigerant stream is at a second pressure;
• passing the third refrigerant stream through a third heat exchanger pass of the plurality of heat exchanger passes, wherein the third refrigerant stream is at a third pressure, wherein the second pressure and the third pressure are both below the first pressure;
• passing a natural gas feed stream through at least a fourth heat exchanger pass of the plurality of heat exchanger passes;
• and
• liquefying at least a portion of the natural gas stream in the cold box using a refrigeration content provided by at least one of the second refrigerant stream or the third refrigerant stream to form an LNG stream.