Process for upgrading natural gas with improved management of CO2

摘要

Disclosed herein are processes for producing a CO-depleted product gas stream. The processes involve feeding a natural gas feed stream comprising greater than about 10 vol % CO to at least one membrane unit comprising a plurality of polymer membranes to provide a CO -rich permeate comprising at least 95 vol % CO and a CO -depleted product gas stream. The polymer membranes comprise a crosslinked polyimide polymer having covalent ester crosslinks and have a CO permeance of at least 20 GPU and a CO /CH4 selectivity of greater than 20, at 35 degrees C and a feed pressure of 100 psia. Also disclosed herein is an apparatus incorporating the crosslinked polyimide polymer for producing a CO -depleted product gas stream from a natural gas feed stream.