A method for liquefying a natural gas feed stream and removing nitrogen therefrom, the method comprising: (a) passing a natural gas feed stream through a main heat exchanger (102, 106, 110) to cool the natural gas stream and liquefy all or a portion of said stream, thereby producing a first LNG stream; (b) withdrawing the first LNG stream from the main heat exchanger (102, 106, 110); (c) expanding and partially vaporizing an at least partially liquefied nitrogen-enriched natural gas stream (144, 344), and introducing said stream (460, 360) into a distillation column in which the stream is separated into vapor and liquid phases; (d) forming a nitrogen-rich vapor product from overhead vapor withdrawn from the distillation column; (e) providing reflux to the distillation column by condensing a portion of the overhead vapor from the distillation column in a condenser heat exchanger; and (f) forming a second LNG stream from bottoms liquid withdrawn from the distillation column; wherein refrigeration for the main heat exchanger (102, 106, 110) and for the condenser heat exchanger is provided by a closed loop refrigeration system, refrigerant circulated by the closed loop refrigeration system passing through and being warmed in the main heat exchanger (102, 106, 110) and passing through and being warmed in the condenser heat exchanger; and wherein the at least partially liquefied nitrogen-enriched natural gas stream is formed by (i) expanding, partially vaporizing and separating the first LNG stream, or an LNG stream formed from part of the first LNG stream, to form a nitrogen-depleted LNG product and a recycle stream composed of nitrogen-enriched natural gas vapor, (ii) compressing the recycle stream to form a compressed recycle stream (134, 138), and (iii) passing the compressed recycle stream through the main heat exchanger (102, 106, 110), separately from and in parallel with the natural gas feed stream, to cool the compressed recycle stream and at least partially liquefy all or a portion thereof, thereby producing the at least partially liquefied nitrogen-enriched natural gas stream, or wherein the at least partially liquefied nitrogen-enriched natural gas stream is formed in step (a), wherein step (a) comprises (i) introducing the natural gas feed stream into the warm end of the main heat exchanger (102, 106, 110), cooling and at least partially liquefying the natural gas feed stream, and withdrawing the cooled and at least partially liquefied stream from an intermediate location of the main heat exchanger (102, 106, 110), (ii) expanding, partially vaporizing and separating the cooled and at least partially liquefied stream to form a nitrogen-enriched natural gas vapor stream and a nitrogen-depleted natural gas liquid stream, and (iii) separately re-introducing the vapor and liquid streams into an intermediate location of the main heat exchanger (102, 106, 110) and further cooling the vapor and liquid streams in parallel, the liquid stream being further cooled to form the first LNG stream and the vapor stream being further cooled and at least partially liquefied to form the at least partially liquefied nitrogen-enriched natural gas stream. (a) passing a natural gas feed stream through a main heat exchanger (102, 106, 110) to cool the natural gas stream and liquefy all or a portion of said stream, thereby producing a first LNG stream; (b) withdrawing the first LNG stream from the main heat exchanger (102, 106, 110); (c) expanding and partially vaporizing an at least partially liquefied nitrogen-enriched natural gas stream (144, 344), and introducing said stream (460, 360) into a distillation column in which the stream is separated into vapor and liquid phases; (d) forming a nitrogen-rich vapor product from overhead vapor withdrawn from the distillation column; (e) providing reflux to the distillation column by condensing a portion of the overhead vapor from the distillation column in a condenser heat exchanger; and (f) forming a second LNG stream from bottoms liquid withdrawn from the distillation column;