8/14/2019 Natural Gas Dehydration With TEG

1/24

Natural GasDehydration with TEG

Workshop

Ti cc ming ging, xy ra hin tng boha ca nc, nc ln vo trong kh gy ramt s vn sau:

+ Hnh thnh hydrates rn c th gy tc

van, ng ng.+ S hin din ca nc v H2S hoc CO2

c th gy ra cc vn v n mn.

+ Nc ngng t gy ra n mn, bo mnng ng.

Ni chung, qu trnh dehydration s dngtrong cc nh my kh p ng cc iukin ca ng ng. C mt s quy trnh snc cho qu trnh dehydration nh: glycols,silicagel, molecular sieves.

Cng nghip sn xut kh t nhin s dngtriethylene glycol (TEG) dehydration khti ni c nhit im sng thp, chnghn nh thit k cho cc thm lc a ngoikhi ca bin Bc Cc hoc min Nam hoccho cc qu trnh lm lnh.

Trong v d ny, nhit im sng canc trong kh kh l -20oC (-4oF) ti 6200kPa (900 psia).

8/14/2019 Natural Gas Dehydration With TEG

2/24

8/14/2019 Natural Gas Dehydration With TEG

3/24

Process Overview

8/14/2019 Natural Gas Dehydration With TEG

4/24

Column Overview

TEG Contactor

TEG Regenerator

8/14/2019 Natural Gas Dehydration With TEG

5/24

Building the Simulation

Defining the Simulation Basis

S dng Peng Robinson EOS vi cc cu tsau: N2, H2S, CO2, C1, C2, C3, i-C4, n-C4,i-C5, n-C5, H2O v TEG.

Starting the Simulation

Add the feed streams

1. Add dng vt liu vo nh trong bng sau:In this cell Enter Name Inlet GasTemperature 30oC (85oF)Pressure 6200 kPa

(900 psia)Molar Flow 500 kgmole/h

(10 MMSCFD)

Component Mole Fraction N2 0.0010H2S 0.0155CO2 0.0284C1 0.8989C2 0.0310C3 0.0148i-C4 0.0059n-C4 0.0030i-C5 0.0010n-C5 0.0005H2O 0.0000TEG 0.0000

2. Add TEG feed vo TEG Contactor:

8/14/2019 Natural Gas Dehydration With TEG

6/24

In this cell Enter Name TEG feedTemperature 50oC (120oF)Pressure 6200 kPa

(900 psia)LiqVol Flow 0,5 m3/h (2USGPM)

Component Mass FractionH2O 0.01TEG 0.99

Mixer Operation

bo ha hi nc, kh v nc c hatrn trc khi vo Contactor.

Add Mixer ha trn Inlet Gas v Water to dng bo ha.

In this cell Enter Connections Name SaturateInlets Inlet Gas

Water to SaturateOutlet Gas + H2OParameters Equalize AllPressureAssignmentWork Sheet 0.5 kgmole/h

(1.1 lbmole/hr)Water toSaturate,Flowrate

100% Water

Water toSaturate,Composition

30oC (85oF)

Gas + H2O,Temperature

80

8/14/2019 Natural Gas Dehydration With TEG

7/24

Separator Operation

Nc t do c tch s b khi kh bithit b separator, FWKO.

Add Separator v cc thng s:In this cell Enter Connections Name FWKO TK Feed Gas + H2OVapour Oulet Gas to Contactor Liquid Outlet FWKO

Contactor Operation

M phng TEG Contactor.

AddAbsorber column vi cc thng s sau:

In this cell Enter Connections Name TEG Contactor No of Stages 8Top Stage Feed Gas to Contactor Bottom StageFeed

Gas to Contactor

Ovhd Vapour Dry GasBottoms Liquid Rich TEGPressuresTop 6190 kPa (897

psia)Bottom 6200 kPa (900

psia)

Valve Operation

8/14/2019 Natural Gas Dehydration With TEG

8/24

Dng Rich TEG qua van VLV-100, p sutdng ra c t ng tnh ton.

Add Valve vi cc thng s sau:

In this cell Enter ConnectionsInlet Rich TEGOutlet LP TEG

Heat Exchange Operation

Regen Feed c gia nhit n 105oC

(220o

F) trong thit b trao i nhitL/R HEX trc khi vo thit b ti sinhRegenerator.

Add Heat Exchange vi cc thng s sau:

In this cell Enter Connections Name L/R HEXTube side Inlet Regen BttmsTube Side Outlet Lean from LR Shell Side Inlet LP TEGShell Side Outlet Regen FeedParametersTubeside Delta P 0.7 kPa

(0.1 psia)Shellside Delta P 70 kPa (10 psia)Work SheetRegen Feed,

Temperature

105oC

Regen Feed,Pressure

110kPa (16 psia)

Regenerator Operation

8/14/2019 Natural Gas Dehydration With TEG

9/24

8/14/2019 Natural Gas Dehydration With TEG

10/24

Do TEG b mt mt nn phi c mt dng bsung duy tr cn bng vt cht .

1. Add Material Stream vi cc thng s sau:

In this cell Enter Connections Name Makeup TEGTemperature 15oC (60oF)Compenent Mole FractionTEG 0.99H2O 0.01

Add Mixer vi cc thng s sau:In this cell Enter ConnectionsInlets Makeup TEG

Lean from L/R Outlet TEG to PumpParametersPressureAssignment

Equalize All

Work SheetLiquid VolFlowrate of TEGto Pump

0.5 m3/h (2USGPM)

Pump Operation

S dng bm nng cao p sut trc khivo Contactor

Add Pump vi cc thng s sau:

In this cell Enter ConnectionsInlet TEG to PumpOulet Pump Out

8/14/2019 Natural Gas Dehydration With TEG

11/24

Energy Pump QWork SheetPressure of PumpOut

6275 kPa (910 psia)

Heat Exchanger

Nhm mc ch lm lnh dng TEG tr liContactor

Add Heat Exchanger vi cc thng s sau:

In this cell Enter ConnectionsTube Side Inlet Pump OutTube Side Outlet TEG to RecycleShell Side Inlet Dry GasShell Side Outlet Sales GasParametersTube Side Delta P 70 kPa (10 psia)Shell Side Delta P 35 kPa (5 psia)Work SheetTEG to Recycle,Temperature

50oC (120oF)

Recycle Operation

Recycle c ci t theo mt khi l thuyttrong qu trnh sn xut. Dng nguyn liuv dng sn phm c t ng tnh tongii hn tun hon . Cc bc sau y din

ra trong qu trnh hi t:+ Hysys s dng cc iu kin n tnh

ton v gii quyt cc vn ca dng trongs dy chuyn sn xut.

8/14/2019 Natural Gas Dehydration With TEG

12/24

+ Sau so snh cc gi tr ca cc dng tnh ton.

+ Da vo s sai khc ca cc gi tr Hysys

s thay i cc gi tr tnh ton.+ Qu trnh tnh ton s lp i lp li cho

n khi cc gi tr trong dng tnh ton phhp vi nhng gi nh.

Trong case ny, lean TEG ( TEG Feed ) banu c tnh c thay th bng dng TEGc tnh n Recycle.

1. Click vo biu tng Recycle. Trong Connections tab in ccthng tin nh hnh sau:

2. Chuyn n trang Tolerance trong Parameters Tab v thchin nh hnh di y:

8/14/2019 Natural Gas Dehydration With TEG

13/24

SAVE YOUR CASE!

8/14/2019 Natural Gas Dehydration With TEG

14/24

Analyzing the ResultsMt trong nhng tiu chun s dng xcnh hiu qu ca qu trnh dehydration lim sng ca kh kh. iu ny c th ddng kim tra bng cch xc nh nhit ngng t ca nc. u tin phi loi bhon ton TEG khi dng v TEG nh hngn im sng ca nc. Tch TEG bngthit b splitter sau lm lnh. Nhit dng ra c tnh ton bng thit b Adjustt tm ra im m ti nc thay itrng thi.

1. Add Component Splitter vi cc gi tr nh sau:

In this cell Enter Connections Name Remove TEGInlet Sales GasOverhead Outlet TEG OnlyBottoms Outlet Water DewpointEnergy Split QParametersBottoms Pressure 6155 kPa (893

psia)Word SheetWater Dewpointtemperature

-20oC (-4oF)

SplitsTEG Fraction inOverhead

1.0

All Other Fractions

0.0

8/14/2019 Natural Gas Dehydration With TEG

15/24

2. Add Separator tch nc ngng.

In this cell Enter ConnectionsFeed Water DewpointVapour Outlet Gas OutLiquid Outlet XS H2O

Adjust s thay i nhit im sng canc cho n khi p ng c yu cudng kh ra.

Balance tm im sng ca dng ti6200 kPa ( 900 psia ).

Add Adjust iu chnh nhit imsng ca nc cho n khi nhit imsng ca dng kh ra l -20oC (-4oF).

Hon thnh nh hnh di y:

8/14/2019 Natural Gas Dehydration With TEG

16/24

Exploring with theSimulation

Ex1:

The addition of stripping gas (slipstreamfrom Sales Gas) will enhance the ability of the Regenerator to remove water from therich TEG. A Tee operation is used to splitSales Gas into 2 streams.

Strip Gas flow = 50 kgmole/h

The stream pressure is 6165 kPa which is toohigh for the Regenerator. Use a Mole balanceto transfer the flow and composition of StripGas to

SG to Regen. Specify the following parameters for SG to Regen:

T = 70C

P = 110 kPaSG to Regen enters as a feed to theRegenerator Reboiler. Does the TEGconcentration in Regen Bttms increase?

8/14/2019 Natural Gas Dehydration With TEG

17/24

8/14/2019 Natural Gas Dehydration With TEG

18/24

8/14/2019 Natural Gas Dehydration With TEG

19/24

8/14/2019 Natural Gas Dehydration With TEG

20/24

8/14/2019 Natural Gas Dehydration With TEG

21/24

8/14/2019 Natural Gas Dehydration With TEG

22/24

8/14/2019 Natural Gas Dehydration With TEG

23/24

8/14/2019 Natural Gas Dehydration With TEG

24/24