Methods and configuration of an NGL recovery process for low pressure rich feed gas
First Claim
1. A method for operating a natural gas liquids (NGL) recovery system, the method comprising:
- separating a feed stream comprising methane, ethane, and propane into a propane and heavier hydrocarbon stream and an ethane-containing residue gas stream, wherein separating the feed stream comprises;
cooling the feed stream to yield a chilled feed stream;
introducing the chilled feed stream into a feed stream separation unit to yield a feed stream separator bottom stream and a feed stream separator overhead stream;
pumping the feed stream separator bottom stream to yield a pressurized feed stream separator bottom stream;
introducing the pressurized feed stream separator bottom stream into a stripper column;
reducing the pressure of the feed stream separator overhead stream using a first JT valve to yield a letdown feed stream separator overhead stream;
introducing the letdown feed stream separator overhead stream into an absorber column;
collecting a stripper column overhead stream from the stripper column;
chilling the stripper column overhead stream to yield a first chilled stripper column overhead stream utilizing refrigerant content from an absorber bottom stream;
chilling the first chilled stripper column overhead stream utilizing propane refrigeration to yield a second chilled stripper column overhead stream;
chilling the second chilled stripper column overhead utilizing refrigerant content from an absorber overhead stream to yield a third chilled stripper column overhead stream;
reducing the pressure of the third chilled stripper column overhead stream using a second JT valve to yield a letdown stripper column overhead stream;
introducing the letdown stripper column overhead stream as a lean reflux to a top of the absorber column, wherein the lean reflux is a two phase stream;
collecting the absorber bottom stream from the absorber column;
pumping the absorber bottom stream to yield a pressurized absorber bottom stream;
heating the pressurized absorber bottom stream to yield a heated absorber bottom stream;
introducing the heated absorber bottom stream to a top of the stripper column;
supplying heat to the stripper column; and
collecting a stripper column bottom stream from the stripper column, wherein the stripper column bottom stream forms the propane and heavier hydrocarbon stream and wherein the propane and heavier hydrocarbon stream comprises propane and heavier hydrocarbons and less than about 2.0% of ethane by volume.
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Accused Products
Abstract
Separating propane and heavier hydrocarbons from a feed stream by cooling the feed stream, introducing the chilled feed stream into a feed stream separation unit, pumping the separator bottom stream, introducing the pressurized separator bottom stream into a stripper column, reducing the pressure of the separator overhead stream, introducing the letdown separator overhead stream into an absorber column, collecting a stripper overhead stream from the stripper column, chilling the stripper overhead stream, reducing the pressure of the chilled stripper overhead stream, introducing the letdown stripper overhead stream into the absorber column, collecting an absorber bottom stream, pumping the absorber bottom stream, heating the absorber bottom stream, introducing the heated absorber bottom stream into the stripper column, and collecting the stripper bottom stream from the stripper column. The stripper column bottom stream includes the propane and heavier hydrocarbons and less than about 2.0% of ethane by volume.
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Citations
21 Claims
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1. A method for operating a natural gas liquids (NGL) recovery system, the method comprising:
separating a feed stream comprising methane, ethane, and propane into a propane and heavier hydrocarbon stream and an ethane-containing residue gas stream, wherein separating the feed stream comprises; cooling the feed stream to yield a chilled feed stream; introducing the chilled feed stream into a feed stream separation unit to yield a feed stream separator bottom stream and a feed stream separator overhead stream; pumping the feed stream separator bottom stream to yield a pressurized feed stream separator bottom stream; introducing the pressurized feed stream separator bottom stream into a stripper column; reducing the pressure of the feed stream separator overhead stream using a first JT valve to yield a letdown feed stream separator overhead stream; introducing the letdown feed stream separator overhead stream into an absorber column; collecting a stripper column overhead stream from the stripper column; chilling the stripper column overhead stream to yield a first chilled stripper column overhead stream utilizing refrigerant content from an absorber bottom stream; chilling the first chilled stripper column overhead stream utilizing propane refrigeration to yield a second chilled stripper column overhead stream; chilling the second chilled stripper column overhead utilizing refrigerant content from an absorber overhead stream to yield a third chilled stripper column overhead stream; reducing the pressure of the third chilled stripper column overhead stream using a second JT valve to yield a letdown stripper column overhead stream; introducing the letdown stripper column overhead stream as a lean reflux to a top of the absorber column, wherein the lean reflux is a two phase stream; collecting the absorber bottom stream from the absorber column; pumping the absorber bottom stream to yield a pressurized absorber bottom stream; heating the pressurized absorber bottom stream to yield a heated absorber bottom stream; introducing the heated absorber bottom stream to a top of the stripper column; supplying heat to the stripper column; and collecting a stripper column bottom stream from the stripper column, wherein the stripper column bottom stream forms the propane and heavier hydrocarbon stream and wherein the propane and heavier hydrocarbon stream comprises propane and heavier hydrocarbons and less than about 2.0% of ethane by volume. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A natural gas liquids (NGL) recovery system commprising:
a deep dewpointing subsystem (DDS) configured to separate a feed stream comprising methane, ethane, and propane into a propane and heavier hydrocarbon stream and an ethane-containing residue gas stream, the DDS comprising; a first heat exchanger configured to receive the feed stream and to output a chilled feed stream; a feed stream separation unit configured to receive the chilled feed stream and to output a feed stream separator bottom stream and a feed stream separator overhead stream; a first JT Valve configured to reduce the pressure of the feed stream separator overhead stream to yield a letdown feed stream separator overhead stream; an absorber column configured to receive the letdown feed stream separator overhead stream into the absorber column and to produce an absorber bottom stream; a first pump configured to receive the absorber bottom stream to output a pressurized absorber bottom stream; a stripper column configured to receive the feed stream separator bottom stream and the pressurized absorber bottom stream and to output a stripper column overhead stream and a stripper column bottom stream, wherein the stripper column overhead stream comprises methane and ethane; a second heat exchanger configured to chill the stripper column overhead stream and to heat the compressed absorber bottom stream and to output a first chilled stripper column overhead stream and a heated absorber bottom stream; a third heat exchanger configured to further chill the first chilled stripper column overhead stream and to output a second chilled stripper column overhead stream, wherein the first heat exchanger is configured to further chill the second chilled stripper column overhead stream and to output a third chilled stripper column overhead stream, a second JT valve configured to reduce the pressure of the third chilled stripper column overhead stream to yield a lean reflux stream, wherein the lean reflux stream is fed to a top of the absorber column, and wherein the stripper column bottom stream forms the propane and heavier hydrocarbon stream and wherein the propane and heavier hydrocarbon stream comprises propane and heavier hydrocarbons and less than about 2.0% of ethane by volume. - View Dependent Claims (16, 17, 18, 19, 20, 21)
Specification