Integration of hydrogen liquefaction with gas processing units

A method comprising:

• compressing a first hydrogen stream, and expanding a first portion to produce a hydrogen refrigeration stream, with the remainder forming a second portion
• cooling a second hydrogen stream against nitrogen refrigeration cycle thereby producing a cool hydrogen stream, wherein at least a portion of the nitrogen refrigeration cycle is provided by a nitrogen refrigeration stream,
• further cooling at least a portion of the cool hydrogen stream against a secondary refrigeration cycle thereby producing a cold hydrogen stream, and a warm hydrogen refrigeration stream, wherein at least a portion of the secondary refrigeration cycle is provided by the hydrogen refrigeration stream,
• compressing the warm hydrogen refrigeration stream,
• mixing the second portion with a high-pressure gaseous nitrogen stream to form an ammonia synthesis gas stream, and
• wherein the first hydrogen stream and the warm hydrogen refrigeration stream are compressed in the same compressor.