System and Method for Separating Natural Gas Liquid and Nitrogen from Natural Gas Streams

A system for removing nitrogen from a feed stream comprising nitrogen, methane, ethane, and other components to produce a methane product stream, an NGL product stream, and a nitrogen vent stream the system comprising:

• a first separator wherein the feed stream is separated into a first overhead stream and a first bottoms stream;
• a first fractionating column wherein the first overhead stream is separated into a second overhead stream and a second bottoms stream;
• an expander for expanding the first overhead stream prior to the first fractionating column;
• a second fractionating column wherein the first bottoms stream and second bottoms stream are separated into a third overhead stream and a third bottoms stream;
• a third fractionating column wherein at least a first NRU feed stream separated into a fourth overhead stream and a fourth bottoms stream;
• a first heat exchanger for cooling a first portion of the feed stream prior to the first separator and cooling a first portion of the second overhead stream prior to the third fractionating column through heat exchange with the fourth bottoms stream and a recycle refrigerant stream;
• a second heat exchanger for cooling the first portion of the second overhead stream after the first heat exchanger and prior to the third fractionating column through heat exchange with the fourth bottoms stream and a recycle refrigerant stream;
• wherein the first NRU feed stream comprises the first portion of the second overhead stream;
• wherein the third bottoms stream is the NGL product stream and comprises at least 90% of the ethane from the feed stream;
• wherein the fourth overhead stream is the nitrogen vent stream;
• and
• wherein the methane product stream comprises the fourth bottoms stream.