Liquefaction of natural gas feeds containing hydrogen

A method comprising:

• (a) cooling and liquefying a hydrogen-containing natural gas feed stream in a natural gas liquefaction plant having at least one gas turbine-driven refrigeration compressor to form a liquefied natural gas stream;
• (b) using a fuel stream to drive at least one of the at least one gas turbine-driven refrigeration compressor;
• (c) reducing the pressure of the liquefied natural gas stream to form an expanded LNG stream;
• (d) separating the expanded LNG stream into an endflash stream and a hydrogen-depleted LNG stream in an endflash separator, the endflash stream having a higher concentration of hydrogen that the hydrogen-containing natural gas feed stream;
• (e) compressing the endflash stream to form a compressed endflash stream;
• (f) storing the hydrogen-depleted LNG stream in an LNG storage tank;
• (g) compressing a BOG stream from the LNG storage tank to form a compressed BOG stream;
• (h) further compressing the compressed BOG stream to form a further compressed BOG stream;
• and
• (i) combining the further compressed BOG stream with the hydrogen-containing natural gas feed stream upstream from the performance of step (a);
• wherein the fuel stream comprises the compressed endflash stream.

A method comprising:

• (a) cooling and liquefying a hydrogen-containing natural gas feed stream in a natural gas liquefaction plant to form a liquefied natural gas stream;
• (b) reducing the pressure of the liquefied natural gas stream to form an expanded LNG stream;
• (c) separating the expanded LNG stream into a first endflash stream and a hydrogen-depleted LNG stream in a first endflash unit, the first endflash stream having a higher concentration of hydrogen than the hydrogen-containing natural gas feed stream, the hydrogen-depleted LNG stream having a lower concentration of hydrogen than the hydrogen-containing natural gas feed stream;
• (d) compressing the endflash stream using an endflash compressor to form a compressed endflash stream;
• (e) using the compressed endflash stream as a fuel stream;
• and
• (f) controlling the pressure at which the endflash compressor is operated to maintain a hydrogen concentration in the fuel stream within a predetermined range.