Semi-open loop liquefaction process

A method of liquefying natural gas, the method comprising the steps of:

• (a) cooling and liquefying a natural gas feed stream via indirect heat exchange with at least a first cold refrigerant stream to form a first liquefied natural gas stream and a warmed gaseous refrigerant stream;
• (b) flashing and separating the first liquefied natural gas stream to form a liquefied natural gas product stream and at least a first flash gas stream;
• (c) combining and compressing the first flash gas stream and the warmed gaseous refrigerant stream to form a compressed refrigerant stream;
• and
• (d) expanding at least a first portion of the compressed refrigerant stream to form the first cold refrigerant stream;
• wherein the natural gas feed stream is kept separate from and is not combined with either the first flash gas stream or the compressed refrigerant stream, and
• wherein step (b) comprises combining, flashing and separating the first liquefied natural gas stream and a second cold refrigerant stream to form the liquefied natural gas product stream and at least the first flash gas stream.