GSU AND GDU

  • View
    697

  • Download
    1

Embed Size (px)

Text of GSU AND GDU

Slide 1

Gas Sweetening&DehydrationProcess

Presented by: Aniruddh Singh Shekhawat

Presentation content

IntroductionH2S & its need of processingGas Sweetening ProcessGas dehydration ProcessRecap

Introduction

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

Sour Gas Effects

Effects of Sour GasIndustrial effectsCorrosionEnvironmental effectsAcid rain, Poisoning

Plant OverviewGas TerminalGSUDPDUCFUGDULPGUKRUCWUSRU

3642SulfurSweet gas to HBJ PLSweet gas to Local consumers

LPG

ARNHCSKO

ACID GASSOUR GASSOUR CONDFrom Offshore

HSDATF

Hydrogen Sulphide

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

Natural Gas Composition at HaziraNote: The composition of components is from ADMA Company

ComponentsMole Fraction at I/LMole Fraction at O/LHydrogen SulphideMethaneEthanePropaneIsobutanenbutaneIsoPentanenPentaneHexaneCarbon Dioxide0.013%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%

Criteria of Process selection

Significant factors are;Type & conc. of impurities.Degree of removal of impurities or selectivity of acid component removal.Volume of the Gas stream.Temp. & Pr. ConditionsHC Composition.Economics

Processes

Non-regenerative

Regenerative processPhysical absorption-water wash, selexol, fluor solvent etc.Chemical absorption- The alkonol-amine processesRegenerative process with elemental sulphur recovery

Gas Sweetening Unit

Processing CapacityPHASE ITRAIN #PHASE IIPHASE IIIPHASE III ACAPACITY313233

3435

36

37385.6 MMSCMD each 5.6 MMSCMD each5.6 MMSCMD each6.3 MMSCMD each

Absorption Process by Amine Solution

Types of Amines

Amine typeChemical formulaMol. Wt.Vapour pressure at 370CRemoval capacity%MEA (Mono ethanol amine)HO C2H4NH261.081.05100DEA (Diethanol amine)(HOC2H4)2NH105.140.05858TEA (Triethanol amine)(HOC2H4)3N148.190.006341DGA (Di glycolamine)H(OC2H4)2NH2105.140.16058DIPA (Di-isopropanol amine)(HOC3H6)2NH133.190.01046MDEA (Methyl diethanol amine)(HOC2H4)2NH3119.170.006151

P301A/B, MULTISTAGE CENTRIFUGALPUMPE305 PREHEATER

V301INLETKOD

ROVsSWEET GAS OUT

V302OUTLETKOD

SWEET GAS TOGDU

SOUR GAS FROM SLUG CATCHER

ABSORBERCOLUMNC301TRAY 9TRAY 7TRAY 5TRAY 3TRAY 1

SOUR GAS IN

RICH MDEA TO V303MP FLASH DRUM

MDEA TANKT301

H2S Absorption

E306COOLER

LV112

SDV104

PV & FV101

Valve type tray

Sweetening PrincipleMDEAMethyl Di Ethanol Amine+H2S

MDEA-H, HS+-Amino Hydro SulphideHigh Press.Low TempAbsorption :Regeneration :MDEA-H, HS

Low Press.High TempMDEAMethyl Di Ethanol Amine+H2S+-

Process ChemistryMDEA 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)

Process Chemistry

H2S reacts to give amine hydrosulfide:H2S + R2NH HS - , R2NH2+CO2 can react directly with amine to form an amine carbonate:2.CO2 + 2R2NH R2NCOO-, R2NH2+3.CO2 + H2O H2CO3CO2 + HO- HCO3-These acids then react with the amine to form amine bicarbonate (HCO3,- RNH2+) and amine carbonate (CO2, (R2NH2+)2).

Process Chemistry (Cont..)

The overall reaction depends upon contact time.Contact time depends onThe gas flow rateThe liquid height above plate area (Weir height)Number of active traysOnly parameter that can be varied is the number of active trays.

PV218

PV216TO FLARETO FUEL GAS HEADER

LV215

FV205

LEAN AMINE

RICH MDEA TO V303MP FLASH DRUM

C303COL.MP FLASH DRUMV303

TO C302

TC558

E302 A/BCOOLER

REGENERATED AMINEFROM C302

E301A/B PHEM. P. Absorption

TO TANK 301

PLATE HEAT EXCHANGERS

ACID GAS OUT

V304REFLUXKOD

REGENERATORCOLUMNC302SOUR GAS IN

E303COOLER

SOUR GAS IN

RICH MDEA FROM V303 THRU E301

PV326

PV327TO FLARE

P304A/B

TO SRULV330LV327

SDV309Amine RegenerationE304REBOILER

REGENERATED AMINE TO TANK

REBOILERS

Kettle-type Reboiler Heat Exchanger Model

Typical Acid Gas Composition at HaziraH2SC1C2C3iC4nC4iC5CO26800 to 69001.480.2.02.02.03.1698.25

Filteration System of MDEA in GSU

X301M

FV221P303A/BP307

FV522V311

DM WATERSUPPLYT303STIRRERCharcoal BedCATRIDGEPRECOAT

PSV1525

PSV1523

PSV1524

MDEA TANKT301

X302

Filteration of MDEAPrecoat filter is designed to filter solids such as iron sulphides & iron carbonatesV311 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 filtersThen the cartridge takes any entrained micro solids

LL103ANTIFOAM TANKV361(Dimethylpolysiloxanic oil)

FUEL GAS BLANKET

P361A/BLL301FLARE GAS

LH302TO FLAREP362A/BFLARE GAS KODV362TOSLOPTANKFUEL GAS FROM C303FUELGASKODV363FUEL GAS

LV403

PV601

METHANOLTANKLH602LL602P363A/BANTIFOAM RETURNFUEL GAS FROM C303Common Utilities at GSU

Alarm System Logic In GSU

LHH224LLL109PB101LL111SOV1104

LLL109PB101

LL111

SOV1101SOV1102

PB101

SOV1318(PV327)SOV1216(PV216)

SOV1317(FV309)

P303A/B ST

MP FL DRM V303C301 ABSORBER

C301 BTM SDV104I/L SDV

Alarm System Logic In GSU (Cont...)

LL334P304A/B ST

LLL109PB101

LL111

SOV1205SOV1206

P301AP301BSOV1309(FV309)

LL335P305 ST

PB121

PL561AB-BYPASS SWITCHFL104

SOV1205LL549

LH110LH219PB111PB112

LL329PB118V304 REF DRMV305 SUMP

(PANEL PUSH BUTTON)T301 TANKABSORBER O/L KODV302C302 REG CLMN(UNLATCHING SWITCH)

EQUIPDETAILSOUR GASHEATERE305SOUR GAS KOD V301ABSORBER COLMN C301FUEL GAS STRIPPERC303RICH AMINE FLASH DRUM V303SWEET GAS COOLER E306FLARE GAS HEATER E307LEAN AMINE STORAGE TANK T301DUTY4.655 X 1.1 MM KCAL/HNANANANA0.778 X 1.1 MM KCAL/H0.905 X 1.1 MM KCAL/HNADIMENSION (MM)NA3300 DIA X 4850TL31OO OD X 11850 H510 DIA X 4000 H2200 DIA X 6000TLNANA6000 DIA X 9000 HDESIGN PRESSUREKG/CM2 NA83831010 NANAATMDESIGN TEMP DEGREE CELSIUSNA49 757575NANA60

Equipment Details (GSU)

Equipment Details (Cont.) EQUIPDETAILTREATED GAS KODV302KETTLE TYPE REBOILER E304REGEN. COL. C302FUEL GAS STRIPPERC303PLATE TYP AMINE-AMINE EX. E301A/BOVERHEAD CONDSRE303REFLUX DRUM V304LEAN AMINE COOLER E302A/BDUTYNA13.77 X 1.2MM KCAL/HNANA7.96X 1.1 MMCAL/H6.91 MMCAL/HNA5.14 X 1.1 MM KCAL/HRDIMENSION (MM)3300 DIA X 4200HNA2900 OD X 19150 H510 DIA X 4000 HNANA1400X 3000HNADESIGN PRESSUREKG/CM2 82.05(S/T): 6.5XFV/9X FV KG/CM2G6.5 & VACUUM10NA(S/T): 6.5 FV/7.56.5 & FV(S/T): 6.5/7.5DESIGN TEMP DEGREE CELSIUS53(S/T):144/20019575NA(S/T): 127/5895(S/T): 88/58

Gas Dehydration Process

Adsorption process

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.

Dehydration ChemistryChemical Formula: HO(C2H4O)3HAdsorbs 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

Dehydration PrincipleHO ( C2 H4 O )3 H

Triethylene Glycol (TEG)H2O

RICH TEGAdsorptionatHigh PressLow Temp

H2ORegenerationat Low PressHigh Temp

Processing CapacityPHASE ITRAIN #PHASE IIPHASE IIIPHASE III ACAPACITY4142

4344

4546

475.7 MMSCMD each5.7 MMSCMD each5.7 MMSCMD each6.3 MMSCMD each

P401A/B, DOUBLE ACTINGRECIPROCATING PUMPV404INLETKOD

TEGGAS OUT

V401OUTLETKOD

SWEET GAS TODPD

SWEET GAS FROM GSU

ABSORBERCOLUMNC401

TRAY 1 TO 9

RICH TEG

LV106

SDV104

PV & FV101

Dehydration Process by adsorptionSURGE DRUMV403

REGENERATED TEG FROM E401E403COOLER

Bubble-Cap Tray

TEG Regeneration

E402REBOILER

VAPOUR VENTTV215

FUEL GAS FOR STRIPPING (FT202)

TO SURGE DRUMV403

C403E401 PHE

HP STEAMDEGASSER DRUMV402

CHARCAOL BED

LV116CATRIDGE FILTERFUEL GAS

RICH TEG FROM C401

C402REGEN

TEG Regeneration ProcessThe 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 valveTwo, the other stream g