Patent ID: 9487458
Filing Date: 2016-11-08
CPC Classification: B01D,C07C,C10G,F25J

Claim Text:
1. A method of removing nitrogen from a hydrocarbonaceous feed gas having a CO2 content of equal or less than 50 ppmv, a water content of equal or less than 0.1 ppmv, and a nitrogen content of at least 3 mol %, comprising: cooling the hydrocarbonaceous feed gas in a heat exchanger to condense C3 separating in a phase separator the condensed C3 feeding the vapor stream into a fractionation column, and using the fractionation column to produce a nitrogen-enriched overhead product and a nitrogen-depleted bottom product; partially condensing the nitrogen-enriched overhead product using refrigeration generated by pressure reduction of a portion of the nitrogen-depleted bottom product to thereby produce a liquid reflux to the fractionation column and a gaseous nitrogen vent stream; and feeding the liquid reflux to the fractionation column.