A hydrocarbon condensate stabilizer and a method for producing a stabilized hydrocarbon condenstate stream

Patent metadata

Field	Value
Publication number	US-2017191748-A1
Application number	US-201515326960-A
Country	US
Kind code	A1
Filing date	Jul 9, 2015
Priority date	Jul 24, 2014
Publication date	Jul 6, 2017
Grant date	—

Abstract

A mixed phase pressurized unstabilized hydrocarbon stream is fed into a stabilizer column at a feed pressure. A liquid phase of stabilized hydrocarbon condensate is discharged from a bottom end of the stabilizer column, while a vapour phase of volatile components from the pressurized unstabilized hydrocarbon condensate stream is discharged from a top end of the stabilizer column. The vapour phase being discharged from the top end of the stabilizer column is compressed and subsequently passed through an ambient heat exchanger wherein partial condensation takes place. The resulting partially condensed overhead stream is separated in an overhead separator into a vapour effluent stream and an overhead liquid stream. After discharging the overhead liquid stream from the overhead separator, it is selectively divided into a liquid reflux stream and a liquid effluent stream. The liquid reflux stream is expanded to the feed pressure and fed into the stabilizer column.

First claim

1 . A method of producing a stabilized hydrocarbon condensate stream, comprising:
providing a pressurized unstabilized hydrocarbon condensate stream at a first temperature, said first temperature being below a second temperature; partially evaporating the pressurized unstabilized hydrocarbon condensate stream whereby the pressurized unstabilized hydrocarbon condensate stream becomes a mixed phase pressurized unstabilized hydrocarbon stream at an initial pressure; expanding the mixed phase pressurized unstabilized hydrocarbon stream from said initial pressure to a feed pressure; feeding the mixed phase pressurized unstabilized hydrocarbon stream at said feed pressure into a stabilizer column via a first inlet device into the stabilizer column; discharging from a bottom end of the stabilizer column a liquid phase comprising stabilized hydrocarbon condensate, wherein the bottom end of the stabilizer column is separated from the first inlet device by a first vapour/liquid contacting device; discharging from a top end of the stabilizer column a vapour phase comprising volatile components from the pressurized unstabilized hydrocarbon condensate stream; compressing the vapour phase being discharged from the top end of the stabilizer column to an auxiliary pressure, thereby forming a compressed overhead vapour stream, whereby the auxiliary pressure is higher than the feed pressure; passing the compressed overhead vapour stream through an ambient heat exchanger; passing an ambient stream through an ambient heat exchanger in indirect heat exchanging contact with the compressed overhead vapour stream, whereby passing heat from the compressed overhead vapour stream to the ambient stream as a result of which partially condensing the compressed overhead vapour stream whereby the compressed overhead vapour stream becomes a partially condensed overhead stream at said second temperature; passing the partially condensed overhead stream into an overhead separator and in the overhead separator separating the partially condensed overhead stream into a vapour effluent stream and an overhead liquid stream; discharging the vapour effluent stream from the overhead separator; discharging the overhead liquid stream from the overhead separator; selectively dividing the overhead liquid stream being discharged from the overhead separator at said second temperature into a liquid reflux stream and a liquid effluent stream; expanding the liquid reflux stream to the feed pressure; feeding the liquid reflux stream at said feed pressure into the stabilizer column via a second inlet device into the stabilizer column at a level gravitationally above the first inlet device, wherein the first inlet device and the second inlet device are separated from each other by a second vapour/liquid contacting device; contacting the liquid reflux stream with a vapour part of the mixed phase pressurized unstabilized hydrocarbon stream in the second vapour/liquid contacting device within the stabilizer column.

2 . The method of claim 1 , wherein pressurized unstabilized hydrocarbon condensate stream comprises at least condensed C 5 + components, and methane, whereby the amount of methane and any volatile inert components is in the range of from 50 mol % to 80 mol % of the pressurized unstabilized hydrocarbon condensate stream.

3 . The method of claim 1 , wherein said partially evaporating the pressurized unstabilized hydrocarbon condensate stream comprises indirectly heat exchanging the pressurized unstabilized hydrocarbon condensate stream in a feed-effluent heat exchanger against an effluent stream being fed to the feed-effluent heat exchanger at the second temperature, wherein the effluent stream at said second temperature consists of one or both of the vapour effluent stream and the liquid effluent stream, preferably comprising at least the vapour effluent stream.

4 . The method of claim 3 , further comprising:
passing the vapour effluent stream being discharged from the overhead separator to the feed-effluent heat exchanger; and/or passing the liquid effluent stream to the feed-effluent heat exchanger.

5 . The method of claim 1 , wherein said ambient stream is at an ambient temperature when entering into the ambient heat exchanger prior to said indirect heat exchanging contact with the compressed overhead vapour stream, and wherein the first temperature is below said ambient temperature and the second temperature is above said ambient temperature.

6 . The method of claim 1 , further comprising adding heat from a heat source to the bottom end of the stabilizer column below the first vapour/liquid contacting device.

7 . The method of claim 1 , wherein said expanding the mixed phase pressurized unstabilized hydrocarbon stream from said initial pressure to a feed pressure and said feeding of the mixed phase pressurized unstabilized hydrocarbon stream into the stabilizer column via the first inlet device comprises:
passing the mixed phase pressurized unstabilized hydrocarbon stream into an inlet separator; separating the mixed phase pressurized unstabilized hydrocarbon stream into a pressurized liquid hydrocarbon feed stream and a pressurized vapour hydrocarbon feed stream; discharging the pressurized vapour hydrocarbon feed stream from the inlet separator; passing the pressurized vapour hydrocarbon feed stream being discharged from the inlet separator into the stabilizer column via the first inlet device; discharging the pressurized liquid hydrocarbon feed stream from the inlet separator; passing the pressurized liquid hydrocarbon feed stream being discharged from the inlet separator into the stabilizer column via a third inlet device located gravitationally below the first inlet device and above the first vapour/liquid contacting device.

8 . The method of claim 7 , wherein said passing of said mixed phase pressurized unstabilized hydrocarbon stream into the inlet separator comprises lowering the pressure from the initial pressure to an intermediate pressure which is lower than the initial pressure and higher than the feed pressure, and further carrying out said separating of the mixed phase pressurized unstabilized hydrocarbon stream in the inlet separator at said intermediate pressure.

9 . The method of claim 7 , further comprising the steps of:
cooling the liquid phase comprising the stabilized hydrocarbon condensate being discharged from the bottom end of the stabilizer column whereby discharging heat from the liquid phase thereby becoming a cooled stream comprising the stabilized hydrocarbon condensate; splitting the cooled stream comprising the stabilized hydrocarbon condensate into a recycle stream and a discharge stream; passing the discharge stream to a condensate storage tank; pumping the recycle stream up to above the first vapour/liquid contacting device and below the first inlet device; and feeding the recycle stream back into the stabilizer column at a level above the first vapour/liquid contacting device and below the first inlet device and at a first flow rate.

10 . The method of claim 9 , further comprising:
determining a second flow rate of the pressurized liquid hydrocarbon feed stream being discharged from the inlet separator; adjusting the first flow rate whereby the sum of the first flow rate and the second flow rate exceeds a pre-determined minimum liquid feed rate into the stabilizer column.

11 . The method of claim 1 , wherein said step of compressing the vapour phase being discharged from the top end of the stabilizer column to an auxiliary pressure comprises passing the vapour phase though an overhead compressor system comprising a plurality of overhead compressors, whereby prior to

Assignees

• Shell Oil Co

Inventors

• Van Leeuwen Lars Hendrik
• Hartenhof Micha
• Jain Divya

Classifications

• F25J2200/02

  in a single pressure main column system · CPC title

• C10L2290/46

  Compressors or pumps · CPC title

• F25J1/0231

  for the working-up of the hydrocarbon feed, e.g. reinjection of heavier hydrocarbons into the liquefied gas · CPC title

• C10G7/02

  Stabilising gasoline by removing gases by fractioning · CPC title

• F25J2200/74

  Refluxing the column with at least a part of the partially condensed overhead gas · CPC title