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

Patent metadata

Field	Value
Publication number	US-10370598-B2
Application number	US-201515326964-A
Country	US
Kind code	B2
Filing date	Jul 9, 2015
Priority date	Jul 24, 2014
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

A mixed phase unstabilized hydrocarbon stream is created by partially evaporating an unstabilized hydrocarbon condensate stream, including indirectly heat exchanging the unstabilized hydrocarbon condensate stream against an effluent stream in a feed-effluent heat exchanger. The mixed phase unstabilized hydrocarbon stream is fed into a stabilizer column. A liquid phase of stabilized hydrocarbon condensate is discharged from a bottom end, while an overhead vapor stream consisting of a vapor phase comprising volatile components from the unstabilized hydrocarbon condensate stream is discharged from a top end of the stabilizer column. The overhead vapor stream is passed through an overhead condenser. The resulting partially condensed overhead stream is separated in an overhead separator into a vapor effluent stream and an overhead liquid stream. The effluent stream against which the unstabilized hydrocarbon condensate stream is heat exchanged in the feed-effluent heat exchanger comprises the vapor effluent stream.

First claim

The invention claimed is:

1. A method of producing a stabilized hydrocarbon condensate stream, comprising:
providing an unstabilized hydrocarbon condensate stream at a first temperature, said first temperature being below a second temperature;
partially evaporating the unstabilized hydrocarbon condensate stream comprising indirectly heat exchanging the 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, whereby the unstabilized hydrocarbon condensate stream becomes a mixed phase unstabilized hydrocarbon stream;
feeding the mixed phase unstabilized hydrocarbon stream 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, said bottom end being gravitationally lower than the first inlet device;
discharging from a top end of the stabilizer column an overhead vapour stream consisting of a vapour phase comprising volatile components from the unstabilized hydrocarbon condensate stream;
passing the overhead vapour stream through an overhead condenser;
passing a coolant through the overhead condenser in indirect heat exchanging contact with the overhead vapour stream, whereby passing heat from the overhead vapour stream to the coolant as a result of which partially condensing the overhead vapour stream whereby the 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, which overhead liquid stream comprises a liquid reflux stream;
feeding the liquid reflux stream 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 unstabilized hydrocarbon stream in the second vapour/liquid contacting device within the stabilizer column;

wherein the effluent stream at said second temperature comprises the vapour effluent stream.

2. The method of claim 1 , further comprising:
passing the vapour effluent stream being discharged from the overhead separator to the feed-effluent heat exchanger.

3. The method of claim 1 , further comprising:
selectively dividing the overhead liquid stream being discharged from the overhead separator at said second temperature into said liquid reflux stream and a liquid effluent stream.

4. The method of claim 3 , further comprising:
passing the liquid effluent stream to the feed-effluent heat exchanger.

5. The method of claim 1 , wherein the bottom end of the stabilizer column is separated from the first inlet device by a first vapour/liquid contacting device, and further comprising adding heat from a heat source to the bottom end of the stabilizer column below the first vapour/liquid contacting device.

6. The method of claim 1 , wherein the step of providing the unstabilized hydrocarbon condensate stream at said first temperature comprises:
providing a natural gas feed stream, said natural gas feed stream comprising methane, ethane, propane, butanes, and C 5 + components, whereby at least 80 mol % is methane and inert components including one or more of nitrogen, argon, and helium;
partially condensing said natural gas feed stream, whereby condensing at least the C 5 + components, thereby creating a partially condensed natural gas stream;
passing the partially condensed natural gas stream through a liquids extraction device and extracting the unstabilized hydrocarbon condensate stream from the refrigerated natural gas stream, said unstabilized hydrocarbon condensate stream comprising at least the condensed C 5 + components.

7. The method of claim 6 , further comprising the step of discharging a lean natural gas stream from the liquids extraction device simultaneously with the unstabilized hydrocarbon condensate stream, and further refrigerating the lean natural gas stream whereby fully condensing the lean natural gas stream, and subsequently depressurizing the lean natural gas stream whereby producing a flash vapour stream and a liquefied natural gas stream.

8. The method of claim 7 , wherein the effluent stream being discharged from the feed-effluent heat exchanger is combined with the lean natural gas stream being discharged from the liquids extraction device, prior to said further refrigerating.

9. A hydrocarbon condensate stabilizer for producing a stabilized hydrocarbon condensate, comprising:
a condensate feed line for providing an unstabilized hydrocarbon condensate stream;
feed-effluent heat exchanger fluidly connected to the condensate feed line and arranged to bring the unstabilized hydrocarbon condensate stream in indirect heat exchanging contact with an effluent stream to partially evaporate the unstabilized hydrocarbon condensate stream thereby forming a mixed phase unstabilized hydrocarbon stream;
a stabilizer column comprising a first inlet device in fluid connection with the feed-effluent heat exchanger to allow feeding of the mixed phase unstabilized hydrocarbon stream into the stabilizer column, the stabilizer column further comprising a bottom end that is located gravitationally lower than the first inlet device, the stabilizer column further comprising a second inlet device 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, the stabilizer column further comprising a top end which top end is located in the stabilizer column gravitationally higher than the second inlet device;
a liquid discharge line fluidly connected to the bottom end of the stabilizer column and arranged to receive a liquid phase comprising stabilized hydrocarbon condensate that is discharged from the bottom end of the stabilizer column;
an overhead line in fluid communication with the top end of the stabilizer column and arranged to receive an overhead vapour stream consisting of a vapour phase comprising volatile components from the unstabilized hydrocarbon condensate stream that is discharged from the top end of the stabilizer column;
an overhead condenser arranged in the overhead line, arranged to receive the overhead vapour stream and to bring the overhead vapour stream in indirect heat exchanging contact with a coolant, whereby passing heat from the overhead vapour stream to the coolant as a result of which partially condensing the overhead vapour stream whereby the overhead vapour stream becomes a partially condensed overhead stream;
an overhead separator arranged in the overhead line for receiving the partially condensed overhead stream from the overhead condenser and separating the partially condensed overhead stream into a vapour effluent stream and an overhead liquid stream comprising a liquid reflux stream;
an effluent vapour line arranged to receive the vapour effluent stream being discharged from the overhead separator;
a liquid reflux line fluidly connected to the overhead separator and arranged to receive the liquid reflux stream and convey the liquid reflux stream to the second inlet device into the stabilizer column;
a reflux exp

Assignees

• Shell Oil Co

Inventors

• Van Leeuwen Lars Hendrik
• Hartenhof Micha
• Jain Divya

Classifications

• F25J3/0247

  separation of CnHm with 4 carbon atoms or more · CPC title

• F25J2205/04

  in the feed line, i.e. upstream of the fractionation step · CPC title

• C10L3/101

  Removal of contaminants · CPC title

• F25J1/0022

  Hydrocarbons, e.g. natural gas · CPC title

• F25J3/0209

  Natural gas or substitute natural gas · CPC title