Download pptx - GSU AND GDU

Gas Sweetening

&Dehydration

Process

Presented by: Aniruddh Singh Shekhawat

• Introduction• H2S & it’s need of processing• Gas Sweetening Process• Gas dehydration Process• Recap

What is Sour Gas?Sour Gas is a Natural Hydrocarbon gas with acid gases; most commonly Carbon dioxide, hydrogen sulphide & to some extent mercaptans.

Natural Gas

Non-Hydrocarbon

(Acid Gas)Hydrocarbon

Industrial effects

Corrosion

Environmental effects

Acid rain, Poisoning

Gas Terminal

GSU DPDU

CFU

GDU

LPGU

KRU

CWU

SRU

36” 42”

Sulfur

Sweet gas to HBJ PL

Sweet gas to Local consumers

LPG

ARN

HCSKO

ACID GAS

SOUR GAS

SOUR COND

From Offshore

HSDATF

• H2S is a highly toxic & Colourless flammable gas

• Corrosive to all metals (less corrosive to SS)

• Can cause catalyst poisoning in refinery processes

• On combustion forms toxic gas SO2.

• 4.3% LEL and 45% HEL by volume with an auto- ignition temperature of 500oF (292oC)

• Heavier than air (1.18 times heavier)• It may accumulate in dangerous

concentrations in drains, valve pits, vessels and tanks.

• Has no heating value.•Yet constitutes a volume-filler

• Corrosive in presence of water.

• Promotes hydrate formation.

CO2

Note: The composition of components is from ADMA Company

Components Mole Fraction at I/L

Mole Fraction at O/L

Hydrogen SulphideMethaneEthanePropaneIsobutanenbutaneIsoPentanenPentaneHexaneCarbon Dioxide

0.013%81.7%6.34%3.72%0.70 %0.86%0.15%0.13%0.05%6.30%

0.0004%82.8%6.39%3.77%0.74%0.84%0.16%0.15%0.07%4.9%

Significant factors are;1. Type & conc. of impurities.2. Degree of removal of impurities or

selectivity of acid component removal.3. Volume of the Gas stream.4. Temp. & Pr. Conditions5. HC Composition.6. Economics

1. Non-regenerative

2. Regenerative process• Physical absorption-water wash,

selexol, fluor solvent etc.• Chemical absorption- The alkonol-

amine processes3. Regenerative process with elemental

sulphur recovery

PHASE ITRAIN #

PHASE II

PHASE III

PHASE III A

CAPACITY313233

3435

36

3738

5.6 MMSCMD each

5.6 MMSCMD each

5.6 MMSCMD each

6.3 MMSCMD each

Amine type Chemical formula

Mol. Wt. Vapour pressure at

370C

Removal capacity%

MEA (Mono ethanol amine)

HO C2H4NH2 61.08 1.05 100

DEA (Diethanol amine) (HOC2H4)2NH 105.14 0.058 58

TEA (Triethanol amine) (HOC2H4)3N 148.19 0.0063 41

DGA (Di glycolamine) H(OC2H4)2NH2 105.14 0.160 58

DIPA (Di-isopropanol amine)

(HOC3H6)2NH 133.19 0.010 46

MDEA (Methyl diethanol amine)

(HOC2H4)2NH3 119.17 0.0061 51

P301A/B, MULTISTAGE CENTRIFUGALPUMP

E305 PREHEATER

V301INLETKOD

ROVs

SWEET GAS OUT

V302OUTLET

KOD

SWEET GAS TOGDU

SOUR GAS FROM SLUG CATCHER

ABSORBERCOLUMN

C301

TRAY 9

TRAY 7

TRAY 5

TRAY 3

TRAY 1

SOUR GAS IN

“RICH” MDEA TO V303MP FLASH DRUM

MDEA TANKT301

H2S Absorption

E306COOLER

LV112

SDV104

PV & FV101

MDEAMethyl Di Ethanol Amine

+ H2SMDEA-H, HS

+ -

Amino Hydro Sulphide

High Press.Low Temp

Absorption :

Regeneration :

MDEA-H, HS

Low Press.High Temp

MDEAMethyl Di Ethanol Amine

+ H2S+ -

• MDEA reacts instantaneously with H2S • H2S reacts to yield Hydro sulphide by proton transfer.• H2S + Amine(R2NH2) HS- + (Amine) H+ • CO2 can only react if it dissolves in water to form

bicarbonate ion.• Then this ion undergoes acid-base reaction with the

amine to yieldH2O + CO2 H2CO3 & CO2 + HO- HCO3-

• These acids then react with amine to form amine bicarbonate (HCO3-, RNH2+) and amine carbonate.

CO2 + H2O + R2NCH3 R2NCH4+ + HCO3- (Slow reaction)

H2S reacts to give amine hydrosulfide:1. H2S + R2NH ↔ HS - , R2NH2+CO2 can react directly with amine to form

an amine carbonate:2. CO2 + 2R2NH ↔ R2NCOO-, R2NH2+3. CO2 + H2O ↔ H2CO3

4. CO2 + HO- ↔ HCO3-5. These acids then react with the amine

to form amine bicarbonate (HCO3,- RNH2+) and amine carbonate (CO2, (R2NH2+)2).

The overall reaction depends upon contact time.Contact time depends on………

• The gas flow rate• The liquid height above plate area (Weir height)

• Number of active trays• Only parameter that can be varied is the number of active trays.

PV218

PV216

TO FLARE

TO FUEL GAS HEADER

LV215

FV205

‘LEAN’ AMINE

“RICH” MDEA TO V303MP FLASH DRUM

C303COL.

MP FLASH DRUMV303

TO C302

TC558

E302 A/BCOOLER REGENERATED AMINE

FROM C302

E301A/B PHE

TO TANK 301

PLATE HEAT EXCHANGERS

ACID GAS OUT

V304REFLUX

KODREGENERATORCOLUMN

C302

SOUR GAS IN

E303COOLER

SOUR GAS IN

“RICH” MDEA FROM V303 THRU’ E301PV326

PV327

TO FLARE

P304A/B

TO SRU

LV330

LV327

SDV309

E304REBOILER

REGENERATED AMINE TO TANK

REBOILERS

Kettle-type Reboiler Heat Exchanger Model

H2S C1 C2 C3 iC4 nC4 iC5 CO2

6800 to 6900

1.48 0.2 .02 .02 .03 .16 98.25

X301M

FV221

P303A/B

P307

FV522

V311

DM WATERSUPPLY

T303

STIRRER

Charcoal Bed

CATRIDGE

PRECOAT

PSV1525

PSV1523PSV1524

MDEA TANKT301

X302

• Precoat filter is designed to filter solids such as iron sulphides & iron carbonates

• V311 holds a bed of charcoal as part of filtration package

• Then the stream (20% of the total MDEA flow in the system) passes thru’ activated charcoal filter removing odour, impurities, colour & hydrocarbon.

• X 301 & X302 are precoat & cartridge type filters• Then the cartridge takes any entrained micro

solids

LL103

ANTIFOAM TANKV361

(Dimethylpolysiloxanic oil)

FUEL GAS BLANKETP361A/B

LL301

FLARE GAS

LH302

TO FLARE

P362A/B

FLARE GAS KODV362

TOSLOPTANK

FUEL GAS FROM C303

FUELGASKODV363

FUEL GAS

LV403

PV601

METHANOLTANKLH602

LL602

P363A/B

ANTIFOAM RETURN

FUEL GAS FROM C303

LHH224 LLL109 PB101

LL111

SOV1104

LLL109 PB101

LL111

SOV1101

SOV1102

PB101SOV1318(PV327)

SOV1216(PV216)

SOV1317(FV309)

P303A/B ST

MP FL DRM V303 C301 ABSORBERC301 BTM SDV104

I/L SDV

LL334P304A/B ST

LLL109 PB101

LL111

SOV1205

SOV1206

P301A

P301B

SOV1309(FV309)

LL335P305 ST

PB121

PL561

AB-BYPASS SWITCH

FL104

SOV1205LL549 LH110 LH219 PB111

PB112

LL329 PB118

V304 REF DRM

V305 SUMP (PANEL PUSH BUTTON)

T301 TANK ABSORBER O/L KODV302

C302 REG CLMN (UNLATCHING SWITCH)

EQUIPDETAIL

SOUR GASHEATERE305

SOUR GAS KOD V301

ABSORBER COLMN C301

FUEL GAS STRIPPERC303

RICH AMINE FLASH DRUM V303

SWEET GAS COOLER E306

FLARE GAS HEATER E307

LEAN AMINE STORAGE TANK T301

DUTY 4.655 X 1.1 MM KCAL/H

NA NA NA NA 0.778 X 1.1 MM KCAL/H

0.905 X 1.1 MM KCAL/H

NA

DIMENSION (MM)

NA 3300 DIA X 4850TL

31OO OD X 11850 H

510 DIA X 4000 H

2200 DIA X 6000TL

NA NA 6000 DIA X 9000 H

DESIGN PRESSUREKG/CM2

NA 83 83 10 10 NA NA ATM

DESIGN TEMP DEGREE CELSIUS

NA 49 75 75 75 NA NA 60

EQUIPDETAIL

TREATED GAS KODV302

KETTLE TYPE REBOILER E304

REGEN. COL. C302

FUEL GAS STRIPPERC303

PLATE TYP AMINE-AMINE EX. E301A/B

OVERHEAD CONDSRE303

REFLUX DRUM V304

LEAN AMINE COOLER E302A/B

DUTY NA 13.77 X 1.2MM KCAL/H

NA NA 7.96X 1.1 MMCAL/H

6.91 MMCAL/H

NA 5.14 X 1.1 MM KCAL/HR

DIMENSION (MM)

3300 DIA X 4200H

NA 2900 OD X 19150 H

510 DIA X 4000 H

NA NA 1400X 3000H

NA

DESIGN PRESSUREKG/CM2

82.05 (S/T): 6.5XFV/9X FV KG/CM2G

6.5 & VACUUM

10 NA (S/T): 6.5 FV/7.5

6.5 & FV (S/T): 6.5/7.5


53 (S/T):144/200

195 75 NA (S/T): 127/58 95 (S/T): 88/58

Adsorption is the process of removing impurities from a gas stream by means of a solid material called adsorbent that has special attraction for the impurities.

• Chemical Formula: HO(C2H4O)3H• Adsorbs water from the Gas until the

equilibrium partial pressure of TEG & water in the gas is reached.

• Bonding with water forms H-OHHO-CH2-CH2-O-CH2-CH2-OCH2-CH2-OH

• Results achieved-1 to 2% of moisture by wt in the outlet

HO ( C2 H4 O )3 H

Triethylene Glycol (TEG)

H2O

RICH TEG

Adsorptionat

High PressLow Temp

H2ORegeneration

at Low PressHigh Temp

PHASE ITRAIN #

PHASE II

PHASE III

PHASE III A

CAPACITY4142

4344

4546

47

5.7 MMSCMD each

5.7 MMSCMD each

5.7 MMSCMD each

6.3 MMSCMD each

P401A/B, DOUBLE ACTINGRECIPROCATING PUMP

V404INLETKOD

TEG

GAS OUT

V401OUTLET

KOD

SWEET GAS TODPD

SWEET GAS FROM GSU

ABSORBERCOLUMN

C401

TRAY 1 TO 9

“RICH” TEG

LV106

SDV104

PV & FV101

SURGE DRUMV403

REGENERATED TEG FROM E401

E403COOLER

E402REBOILER

VAPOUR VENT

TV215

FUEL GAS FOR STRIPPING (FT202)

TO SURGE DRUMV403

C403

E401 PHE

HP STEAM

DE

GA

SS

ER

DR

UM

V40

2

CH

AR

CA

OL

BE

D

LV116

CATRIDGE FILTER

FUE

L G

AS

‘RIC

H’ T

EG

FR

OM

C40

1

C402REGEN

• The relatively cool TEG from C401 bottom does two things;• One, it brings down the temperature of the vapour leaving the

C402 top thru’ three way valve• Two, the other stream goes into the plate heat exchanger E401

to cool the regenerated glycol before going into V303 and in turn getting itself heated upto 145 deg before entering C402 having 4 bubble cap trays.

• TV 212 controls the temp of reboiler where the TEG at 185 deg overflows into the attached C403 end mounted on the side of the reboiler. C403 is a packed column where the hot fuel gas from V401/402 preheated inside a 2nd coil in E402, strips the glycol of remaining moisture to achieve 99.7% purity.

• This stripped glycol comes in contact at E401 with the cooler rich TEG from C401 & reaches 80-deg.

• Stripper gas is piped into E402 & V403 to maintain +ve pressure.

• The reciprocating TEG pumps attached to V403 completes the cycle of pumping TEG into the column C401.

LLL105 FL106 PB101SOV1103

LL218 PB106P403 ST

LLL105 FL106 PB101SOV1101

LLL105 FL106 PB101P401A/B STOP

LLL105 PB101SOV1102

LLL133 PB101SOV1105

THH210 PB101SOV1212 (TV212)

LLL132 PB101SOV1104

C401 ABSORBER TEG FLOWLOW SWITCH

V404 I/L KOD

V401 DRYGAS SCRUBBER

E402 REBOILER TEMP

SUMP V405

I/L SDV

O/L SDV

C401 BOTTOM

EQUIP

DETAIL

FEED GAS KOD V404

GLYCOL ABSORBER COLUMN C401

DRIED GAS SCRUBBER V401

RICH GLY DEGASSING DRUM V402

LEAN GLY TRIM COOLER E403

DUTY NA NA NA NA 0.164X1.2MMKCAL/H

DIMENSION (MM)

3300 DIA X 3250H

2800 DIA X 9000H

3600 DIDX 4200H

1100 DIA X 3250H

2200 DIA X 6000TL

DESGN PRESSUREKG/CM2

81.4 81.4 81.06 10 (S/T): 7.5/ 82


55 60 60 55 (S/T): 60/120

EQUIP

DETAIL

GLYCOL STRIPPG COLUMNC403

GLYCOL REG. C402

LEAN GLYCOL SURGE DRUM V403

LEAN GLYCOL TANK T401

GLY-GLY HEAT EXCH. E401A/B

RICH GLYCOL REBOILERE402

DUTY NA NA NA NA 0.627X1.2MM KCAL/H

0.625X1.2 MM KCAL/H

DIMENSION (MM)

500 DIAX 2150H

600DX 4200L (UPPER) 800X2590 (LOWER)

1000 DIA X 4000L

4500 DIA X 3000H

NA NA

DESGN PRESSUREKG/CM2

1.1 1.1 1.1 ATM (S/T): 1.0/ 39 (S/T): 1.0/ 39 & FV


240 220(TOP) 240(BTM)

240 60 (S/T): 240/220

(S/T): 240/260

The incoming sour gas is treated by washing/scrubbing with aqueous solution MDEA (Methyldiethanolamine).

Selectively removing H2S from 1375ppm (max) down to 4ppm & limiting CO2 co absorption to max of 32%.

Processing Acid Gas at SRU for Sulphur Removal.Removing moisture, entrained or enriched during

sweetening, in Gas Dehydration Unit with TEG upto -46 deg celsius.