PROCESS FOR UPGRADING NATURAL GAS WITH IMPROVED MANAGEMENT OF CO2

摘要

Disclosed herein are processes for producing a CO2-depleted product gas stream. The processes involve feeding a natural gas feed stream comprising greater than about 10 vol % CO2 to at least one membrane unit comprising a plurality of poly-mer membranes to provide a CO2 -rich permeate comprising at least 95 vol % CO2 and a CO2 -depleted product gas stream. The polymer membranes comprise a crosslinked polyimide polymer having covalent ester crosslinks and have a CO2 permeance of at least 20 GPU and a CO2 /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 CO2 -depleted product gas stream from a natural gas feed stream.