Systems and methods for natural gas liquefaction capacity augmentation using supplemental cooling systems and methods to improve the efficiency of a liquefaction cycle for producing liquefied natural gas (LNG).

A method for producing liquefied natural gas (LNG) is provided. The method may include feeding natural gas from a high-pressure natural gas source to a separator and removing a non-hydrocarbon from the natural gas. A portion of the natural gas from the separator may be precooled, and the precooled natural gas may be cooled in a first heat exchanger with a first refrigeration stream. A first portion of the cooled natural gas may be expanded in a turbo-expander to generate the first refrigeration stream. A second portion of the cooled natural gas may be cooled in a second heat exchanger with the first refrigeration stream and expanded in an expansion valve to produce a two-phase fluid containing the LNG and a vapor phase. The LNG may be separated from the vapor phase in a liquid separator and stored in a storage tank.