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E&C Cry og en i cs Standard P lan ts

Nitrogen Generation Unit APSA L1)Training documentation

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Generic part1

stDay

Welcoming introduction

Process introduction

Summary and training program philosophy

Nitrogen Generation Unit systemic presentation

PFD & PID

Compression modulePurification module

2sd

Day

Heat Exchange module

Distillation module

Cold Production module

Mass balance

Safety : CnHm risks, safely operation

Operation training3rd Day

Process control overview

Start-up and shutdowns

Deriming / Drying & exceptional regeneration

Main control loops

Alarms and trips

Operating manual

R01/R02 timing

Supervision in steady conditions

Trouble shooting

quiz Operators questions and answers

Taining - PERU LNGNitrogen Generation Uni t

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PRESENTATIONPRESENTATIONPRESENTATION

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1. Generalities

1.1. Nitrogen On-Site Supply System

N2 Production (Nm3/h)

Bulk SupplyBulk Supply

10100 1000 10000

100%

99.9%

95%

SPISPISmall MembranesSmall Membranes

AMSAAMSALarge MembranesLarge Membranes

APSA LAPSA L

APSA LEAPSA LELargeLarge CryoCryo..

High PurityHigh Purity

LINLIN

APSAAPSASmallSmall CryoCryo..

N2 purity

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1. Generalities

1.2. APSA L /LE : Process and Markets

ChemicalsChemicals

RefineriesRefineriesGlassGlass

APSAAPSA--LL

GlassGlassAPSAAPSA--LCLC

APSAAPSA--LELE ElectronicsElectronics

Classic

7-10 barA N2

Claude Cycle

2-3 barA N2

Booster Re-cycle

Ultra High Purity

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1. Generalities

1.3. Air Separation Unit (ASU) Inlet & Outlet

Air

SeparationUnit

PRODUCTS:

O2, N2, Ar(gas or liquid)

SOURCE :

Atmospheric Air

WASTE NITROGEN

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1. Generalities

1.4. Raw material composition

OXYGENNITROGENARGON

HELIUMNEON

KRYPTONXENON

HYDROGENSTEAM

CARBON DIOXIDE

HYDROCARBONS {

O2N2Ar

HeNeKrXeH2

H2O

CO2CH4

20,9 %78,1 %0,93 %

5,24 ppm18,18 ppm1,139 ppm0,086 ppm0,5 ppm

variable300 700 ppm

3 5 ppm

ELEMENTS SYMBOLCOMPOSITION

IN VOLUME

< 0.5 ppmC2+

Principal

Rare gas

Impurities

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1. Generalities

1.5. Cryogenic production stages ?

DISTILLATIONCOMPRESSION

PURIFICATION

HEAT

EXCHANGE

COLD

PRODUCTION

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1. Generalities

1.6. Cryogenic production modular approach

COMPRESSION

PURIFICATION

HEAT

EXCHANGE

DISTILLATION

COLD

PRODUCTIONResidual Gas

GASEOUS

PRODUCTS

LIQUID

PRODUCTS

Air

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1. Generalities

1.7. Plants Modules Overview

COMPRESSION

PURIFICATION

COLD PRODUCTION

HEAT

EXCHANGE

DISTILLATION

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1. Generalities

1.8. APSA L : Global Scheme

Nitrogen recoveryNitrogen recovery 40%40%

APSA LAPSA L

GANGAN

Residual GasResidual Gas

AIRAIR

LINLIN

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1. Generalities

1.9. APSA L : Process Cycle

Gaseous N2to customer

Liquid N2to backup

Residual Enriched Gas (>35% O2)

Cooling WaterPower Civil Works

R01 R02

D01

Compression Purification Cold Production Heat Exchange Distil lation

Air

inlet

C01

K01

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AIR PURIFICATIONAIR PURIFICATIONAIR PURIFICATION

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TO REMOVE THE VARIOUS AIR CONTAMINANTS IN ORDER TOPREVENT TROUBLES IN APSA UNITS:

TEMPERATURE ~ -180C

TO REMOVE THE VARIOUS AIR CONTAMINANTS IN ORDER TOPREVENT TROUBLES IN APSA UNITS:

TEMPERATURE ~ -180C

WATER (air moisture)WATER (air moisture)

Carbon Dioxide CO2Carbon Dioxide CO2

Hydrocarbons CnHmHydrocarbons CnHm

Nitrous oxide (N2O)Nitrous oxide (N2O)

Air Purification OBJECTIVESOBJECTIVESOBJECTIVES

Ai P ifi i

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Purification requirementsPurificationPurification requirementsrequirements

- unit corrosion

- plugging (pipes, exchangers, column) by solidification

due to cryogenic temperature (0C / ice)

- unit corrosion


due to cryogenic temperature (0C / ice)

WATER

- plugging (pipes, exchangers, column) by solidif ication

due to cryogenic temperature (-130C / solid CO2)


due to cryogenic temperature (-130C / solid CO2)

O

- explosion r isk in the vaporizers with oxygen enrichedatmosphere (Rich Liquid, Oxygen)

- explosion risk in the vaporizers with oxygen enrichedatmosphere (Rich Liquid, Oxygen)

nHm

- explosion risk with CnHm- explosion risk with CnHm O

Air Purification

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Air CompositionAir Composition Inlet Comp.Inlet Comp. Inlet Comp.Inlet Comp. PurifPurif. Outlet. Outlet

NormalNormal PeakPeak MaxMax allowaballowab

N2 Nitrogen 78.11 %O2 Oxygen 20.96 %

Ar Argon 0.93 %

H2O Water saturation

CO2 Carbon Dioxide 350 450 ppm 600 ppm 0.1 ppmCnHm Hydrocarbons < 0.1 ppm 0.5 ppm

Ne Neon 18 ppm

He Helium 5.2 ppm

CH4 Methane 1 6 ppm 15 ppm 8 ppmKr Krypton 1.139 ppm

H2 Hydrogen 0.5 ppm

Xe Xenon 0.086 ppm

+ other natural or industr ial impurities : hydrocarbons,CO, H+ other natural or industrial impurities : hydrocarbons,CO, H22S, NOS, NO22 ..........

Air Composition / Air ContaminantsAir Composition / Air ContaminantsAir Composition / Air Contaminants

Air Purification

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Contaminant-free

Air

Air with

contaminants:

H2O, CO2,CnHm

OBJECTIVES:

ELIMINATION OF WATER IN VAPOUR FORM

ELIMINATION OF CARBON DIOXIDE CO2

ELIMINATION OF HYDROCARBONS EXCEPTMETHANE CH4 and some other CnHm

OBJECTIVES:

ELIMINATION OF WATER IN VAPOUR FORM

ELIMINATION OF CARBON DIOXIDE CO2

ELIMINATION OF HYDROCARBONS EXCEPTMETHANE CH4 and some other CnHm

Air passes through upward a vesselequipped with two specific materials:

-ALUMINA: to trap water molecules

- MOLECULAR SIEVE: to trap CO2 and

Hydrocarbon molecules

Air passes through upward a vessel

equipped with two specific materials:

-ALUMINA: to trap water molecules

- MOLECULAR SIEVE: to trap CO2 and

Hydrocarbon molecules

ALUMINA:

WATER

MOLECULAR

SIEVE:

CO2, CnHm

Process presentationProcessProcess presentationpresentationAir Purification

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TheADSORPTION process occurs

in 2 steps:

- first, an attraction of the

molecules to the adsorbent

- then, a diffusion of the

molecules into the pores where

they are fixed (or trapped).

TheADSORPTION process occurs

in 2 steps:

- first , an attraction of the

molecules to the adsorbent

- then, a diffusion of the

molecules into the pores where

they are fixed (or trapped).Adsorbent

Pores

ATTRACTION

DIFFUSION/

FIXATION

Molecules

ALUMINA and MOLECULAR SIEVE

are solid materials in the form ofporous particles of 2 to 5 mm

diameter: they are called

ADSORBENTS.

ALUMINA and MOLECULAR SIEVE

are solid materials in the form of

porous particles of 2 to 5 mm

diameter: they are called

ADSORBENTS.

Adsorption ProcessAdsorptionAdsorption ProcessProcessAir Purification

Air Purification

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Reversible Process : Adsorption & Desorption

Adsorption increases (the amount of

adsorbed molecules increases) when:

the pressure increases

the temperature decreases

Adsorption increases (the amount of

adsorbed molecules increases) when:

the pressure increases

the temperature decreases

ADSORPTION IS A REVERSIBLE PROCESS:

if the pressure decreases or if the temperature increases, theadsorbed molecules will be able to leave the pores of the adsorbentparticles: this is the Desorption of the adsorbent.

(also called Regeneration)

ADSORPTION IS A REVERSIBLE PROCESS:

if the pressure decreases or if the temperature increases, theadsorbed molecules will be able to leave the pores of the adsorbentparticles: this is the Desorption of the adsorbent.

(also called Regeneration)

Thus, for a fixed adsorbent quantity, we design a cyclic processwith alternating phases: adsorption/desorption.

we can play with the temperature: TSA cycle (TemperatureSwing Adsorption)

we can play with the pressure: PSA cycle (Pressure SwingAdsorption).

Thus, for a fixed adsorbent quantity, we design a cyclic processwith alternating phases: adsorption/desorption.

we can play with the temperature: TSA cycle (TemperatureSwing Adsorption)

we can play with the pressure: PSA cycle (Pressure SwingAdsorption).

AdsorbedAdsorbedphasephase

GaseousGaseousphasephase

SolidSolid

Adsorption ProcessAdsorptionAdsorption ProcessProcessAir Purification

Air Purification

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The name of Adsorbents designates porous solid materials.

Their main characteristic is a maximum surface (active zone for the adsorptionprocess) in a small

volume: we define the specific area.

Adsorbents come in different forms:- spherical balls- cylindrical pellets- irregular crushed particles

Chimical

formula

Specific

area

m2/g

Pore diameter

Angstrm

(10-10

m)

ACTIVATEDCARBON

C 800 to 1500 40 to 5000

ALUMINA AL2O3 300 to 350 10 to 40

MOLECULAR

SIEVE:

Type A, Type X

SiO2, Na2OCaO, K2O

900 3 to 10

Each gram of product

particle has a surface

equivalent to a tennis

court

Adsorbent characteristicsAdsorbentAdsorbent characteristicscharacteristicsAir Purification

S fAir Purification

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Affinity (Adsorbent / Molecule) depends on :

The type of adsorbent: presence of attraction field diameter of the pores

The type of adsorbent:presence of attraction fielddiameter of the pores

The type of molecule: their physical and chemical characteristics determine the intensity of the

adsorbent attraction: so, we designate

molecules strongly attracted (with electrical moment)and molecules weakly attracted (neutral molecules) the size of the molecules must be smaller than the diameter of the pores:

thus, nitrogen molecule is able to pass into a 4 pore, but not into a 3 pore.

The type of molecule:their physical and chemical characteristics determine the intensity of the

adsorbent attraction: so, we designatemolecules strongly attracted (with electrical moment)and molecules weakly attracted (neutral molecules)

the size of the molecules must be smaller than the diameter of the pores:thus, nitrogen molecule is able to pass into a 4 pore, but not into a 3 pore.

Adsorbed molecules

ACTIVATED CARBONOil vapour:

Hydrocarbons C2 and C3 typesALUMINA H2O

MOLECULAR

SIEVE

C2H2, NO2, CO2, H20

Selectivity of the processSelectivitySelectivity of theof the processprocessAir Purification

Ch iCh i ff d bd b tAir Purification

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The function of the adsorption process for an APSA unit is to trap in vapour form

the air contaminants such as water, carbon dioxide CO2 and hydrocarbons, beforefeeding the cold box.

To trap water, knowing that air is always saturated after compression process, thechoice indifferently could be molecular sieve or alumina.

We prefer alumina for the following reasons:

- alumina is less sensitive to the possible presence of liquid water particles- the temperature of regeneration process for alumina is colder:

around 40C for alumina, 250C for molecular sieve

To trap CO2, the only choice is molecular sieve.

The same for hydrocarbons, mainly made up of acetylene C2H2:it is not possible to trap methane CH4 by the adsorption process.

MOLECULAR SIEVECO2, C2H2


ALUMINAH2O

ALUMINAH2O

Choice of adsorbentsChoiceChoice ofof adsorbentsadsorbentsAir Purification

Ad ti W tAd ti W t llAir Purification

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Saturated zone front Clean zone

ADSORPTION

DESORPTION (REGENERATION)

END OF DESORPTION (REGENERATION)

Dry gas

Saturated Gas

Saturated Gas Dry gas

Adsorption: Water analogyAdsorption: WaterAdsorption: Water analogyanalogyAir Purification

I t ll ti d iI t ll ti d iI t ll ti d iAir Purification

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The design of the installation is a combination with two types of adsorbents:

first , compressed air passes through a bed of alumina in order to trap water

then, compressed air passes through a bed of molecular sieve intended to trapCO2 and Hydrocarbons

Thus, we keep molecular sieve free of moisture contamination.

The design of the installation is a combination with two types of adsorbents:

first, compressed air passes through a bed of alumina in order to trap water

then, compressed air passes through a bed of molecular sieve intended to trapCO2 and Hydrocarbons

Thus, we keep molecular sieve free of moisture contamination.

AIR


ALUMINAH2O

AIR

Adsorber

V-6701 A/BALUMINA

MOLECULAR

SIEVE

Installation designInstallation designInstallation designAir Purification

Ad ti / R ti C lAdsorption / Regeneration CycleAdsorption / Regeneration CycleAir Purification

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Using a fixed amount of adsorbent, we know that the duration of adsorption process will be limited:

after a certain duration of air circulation, the pores of the adsorbent become saturated:- with water molecules for alumina- with CO2 and Hydrocarbon molecules for molecular sieve

We obtain the saturation of the adsorbents: the adsorption process is

over.

Using a fixed amount of adsorbent, we know that the duration of adsorption process will be limited:

after a certain duration of air circulation, the pores of the adsorbent become saturated:- with water molecules for alumina- with CO2 and Hydrocarbon molecules for molecular sieve

We obtain the saturation of the adsorbents: the adsorption process is

over.

To achieve a continuous air purification

compatible with the non-stop distillationprocess of APSA unit, we need an

operating cycle with two adsorbers.

An arrangement with two adsorbers in parallelallows to purify compressed air with one adsorber

(ADSORPTION phase), while the second one is indesorption process (REGENERATION phase).

When the first adsorber is close to the limit ofadsorption capacity, we perform a reverse

operation in order to feed with compressed air the

second adsorber, which is contaminant-free thanksto the previous regeneration process.

To achieve a continuous air purif ication

compatible with the non-stop disti llationprocess of APSA unit, we need an

operating cycle with two adsorbers.

An arrangement with two adsorbers in parallelallows to purify compressed air with one adsorber

(ADSORPTION phase), while the second one is indesorption process (REGENERATION phase).

When the first adsorber is close to the limit ofadsorption capacity, we perform a reverse

operation in order to feed with compressed air the

second adsorber, which is contaminant-free thanksto the previous regeneration process.

Contaminant-free

air

Air with

contaminants

ADSORPTION

Adsorption / Regeneration CycleAdsorption / Regeneration CycleAdsorption / Regeneration CycleAir Purification

REGENERATION

Ad ti f t i th b dAdsorption front in the bedAdsorption front in the bedAir Purification

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0100200300400500

0

0 1 2 3 4 5

CO2 (ppm) Adsorbed quantity

Bed

Height

t = 100 min

t = 20 min

Adsorbed

quantity

Adsorption front in the bedAdsorption front in the bedAdsorption front in the bedAir Purification

Air wi th contaminants

Contaminant-free

air

Regeneration front in the bedRegeneration front in the bedRegeneration front in the bedAir Purification

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CO2 (ppm) Desorbed quantity

Bed

He

ight

Saturated Vaporized

Rich Liquid

Vaporized

Rich Liquid

0100200300400500

0

0 1 2 3 4 5

Desorbed

quantity

Regeneration front in the bedRegeneration front in the bedRegeneration front in the bedAir Purification

Regeneration fluid : Vaporized Rich Liquid (VRL)

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Air Purification TechnologyTechnologyTechnology

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Horizontal beds

Adsorption phase :

Cycle time : 150 min

Air pressure : 8.1 bar g Air temperature : 40C

Regeneration phase :

Regeneration temperature : 90C

(heater outlet) Air pressure : 0.1 bar g

Heating duration : ~20 min

Cooling duration : ~100 min

Horizontal beds

Adsorption phase :

Cycle time : 150 min

Air pressure : 8.1 bar g Air temperature : 40C

Regeneration phase :

Regeneration temperature : 90C

(heater outlet) Air pressure : 0.1 bar g

Heating duration : ~20 min

Cooling duration : ~100 min

Mole Sieve bed

Alumina bed

Air

VaporizedRich Liquid

Air

TechnologyTechnologyTechnology

Vaporized

Rich Liquid

Regeneration fluid : Vaporized Rich Liquid (VRL)Regeneration fluid : Vaporized Rich Liquid (VRL)

Air Purification V01 / V02 InstallationV01 / V02 InstallationV01 / V02 Installation

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VRL Air to Cold Box

Event

Air

V-6701A

V-6701B

Electr ic heater EH-6701

AdsorptionPhase

RegenerationPhase

CVAG06B

KV 530

CVAG06A

CVWO009BCVWO009A

KV 525KV 515

KV 520KV 510

KV 516 KV 526

V01 / V02 InstallationV01 / V02 InstallationV01 / V02 Installation

VRL

Air Purification Purification cyclePurification cyclePurification cycle

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Purification steps

HP Isolation

Depressurization

Blow-Off

Heating

Cooling

LP Isolation

Pressurization

Parallel position

Adsorption

Purification cyclePurification cyclePurification cycle

Air

VRL

Air

Bottle in

Adsorption

phase

VRL

Bottle in

Regeneration

phase

Air Purification Pressure cyclePressure cyclePressure cycle

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Pressure cyclePressure cyclePressure cycle

Air

VRL

Air

Bottle in

Adsorption

phase

VRL

Bottle in

Regeneration

phase

Bott le 1

Bott le 2

time

press

ure

time

Heating Cooling

Heating Cooling

pres

sure

Adsorption

Adsorption

Regeneration

Regeneration

Air Purification Automatic sequenceAutomatic sequenceAutomatic sequence

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On line V6701 B

HP Isolation V6701 A

VRL Cold Box

Event

Air

V6701

A

V6701

B

Depressurization V6701 A

VRL Cold Box

Event

Air

V6701

A

V6701

B

Automatic sequenceAutomatic sequenceAutomatic sequence


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VRL Cold Box

Event

Air

V6701

A

V6701

B

Heating V6701 ABlow-Off V6701 A

VRL Cold Box

Event

Air

V6701

A

V6701

B

Automatic sequenceAutomatic sequenceq


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Air

VRL Cold Box

Event

V6701

A

V6701

B

LP Isolation V6701 ACooling V6701 A

VRL Cold Box

Event

Air

V6701

A

V6701

B

Automatic sequenceqq


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Parallel PositionPressurization V6701 A

VRL Cold Box

Event

Air

V6701

A

V6701

B

VRL Cold Box

Event

Air

V6701

A

V6701

B

uto at c seque ceqq

Air Purification Temperature profileTemperature profileTemperature profile

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GoodRegeneration

indicator

Time

Temperature

Heating Cooling

Inlettemperature

Outlet

temperatureCold Desorption Hot Desorpt ion

Heat Peak

Heating temperature

VRL temperature

at cold box outlet

p pp pp p

Air Purification

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What does the purif ication process look like ?

Air Purification

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What does the purif ication process look like ?

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EXCHANGERSEXCHANGERSEXCHANGERS

4. Heat Exchange

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4.1. Why exchange the heat ?

Gaseous N2to customer

Liquid N2to backup

Residual Enriched Gas (>35% O2

)

R01 R02

D01

Compression Purification Cold Production Heat Exchange

Distillation

Air

inlet

C01 K01

CRYOGENICCRYOGENICNONNON--CRYOGENICCRYOGENIC

4. Heat Exchange

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4.2. Principles of Heat Exchange

GOAL

To get air at good conditions for the distillation

To warm up gaseous product from the cryogenictemperature to the ambient one

PRINCIPLESHeat flux from the Hot fluid to cold fluid

Driving force = temperature difference

Counter flow arrangement

Heat exchange in an aluminium brazed Heat Exchanger

4. Heat Exchange

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4.3. Heat exchange formula

where

H = Duty or Heat exchanged (kcal/h)K = Heat exchange coeff

= f(fluids, material, flow) (kcal/h.m2.C)

S = Surface (m2)

T = Average temperature difference between hot

and cold f luids (C)

H = K . S

. Ln(T)

4. Heat Exchange

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4.4. Heat exchange formula

H = Q . Cp

. T

where

H = Duty or Heat exchanged (kcal/h)Q = Flowrate

(Nm3/h)

Cp = Specific heat (kcal/Nm3/C)

T = Temperature difference for the same fluid (C)

4. Heat Exchange

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4.5.Three types of heat exchanger

Cross currentCross current

++

++

CounterCounter--currentcurrent CoCo--currentcurrent

++

4. Heat Exchange

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4.6. Co-current exchanger

Insulation

-100C

0C

-100C

-50C

-50C

-50C

Cold Nitrogen

Cold Nitrogen

Hot Nitrogen

Same number of hot passages and cold passages

Temperature of Hot Nitrogen at the end of the exchanger ?

4. Heat Exchange

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4.7. Counter-current exchanger

Cold Nitrogen

Cold Nitrogen

Hot Nitrogen

-100C

0C

-5C -100C

-95C

-5C -10C

-5C

-10C

Same number of hot passages and cold passages

Temperature of Hot Nitrogen at the end of the exchanger ?

4. Heat Exchange

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4.8. T Warm End definition

Brazed aluminium HX

T cold = 0C

AirWN2

GAN

T cold

T warm

end

T warm end ~ 2C

Loss of cold capacity to beproduced by the turbine

4. Heat Exchange

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4.9. Basis about heat exchange diagram

Temperature (C)

Exchan

gedheat(k

cal/h)

Coldcom

posite

Hotc

ompo

site

-100C

0C

-5C -100C

-95C

N2

N2

Air

-5C -50C

-45C

-50C

0-95 -5-100

T Warm End ?

4. Heat Exchange

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4.10. Real heat balance diagram for APSA L

0

200000

400000

600000

800000

1000000

1200000

1400000

-200 -150 -100 -50 0 50

Temperature (C)

H Heat flow (kcal/h)

Hot composite

Cold composite

4. Heat Exchange

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4.11. Heat balance

T

HT1

T2T3

T4T1

T2T3

T4Warm end

Cold end

QC

QF

Heat Balance :Heat Balance :

H = HC

= QC

. CpC

. ( T2

T1

)

= -

HF = -

QF . CpF . ( T4 T3 )

H = Q . Cp . T

4. Heat Exchange

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13PERU LNG - 2009

4.12. Heat exchange exercise

25C

T=?-100C

20C

Warm end

Cold end

8 Nm3/h

5 Nm3/h

AIR

NITROG

EN

We consider a counter flow

exchanger

We want to warm up 5 Nm3/h ofN2 from - 100 to 20C at 1 bar abs

A 8 Nm3/h flowrate of Air is

available at 25C and 5 bar abs

Cp(Air) = 0.31 kcal/Nm3/C

Cp(N2) = 0.31 kcal/Nm3/C

Air temperature at cold end ?

4. Heat Exchange

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14PERU LNG - 2009

4.13. Heat exchange exercise result

25C

T= -50C-100C

20C

Warm end

Cold end

8 Nm3/h

5 Nm3/h

AIR

NITROG

EN

Heat exchanged by Nitrogen

HN2

= 5x0.31x[20-(-100)] = 186 kcal/h

Heat exchanged by air

HAIR

= 8x0.31x[T-25]

But HN2 = - HAIR = 186 kcal/h Then 8x0.31x[T-25] = -186 kcal/h

Finally T = -186/(8x0.31)+25 = -50C

4. Heat Exchange

4 14 I fl f f l t h t h

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4.14. Influence of f lowrate on heat exchange

Flow evolution T warm end T cold end

Hot fluid

Cold f luid

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4. Heat Exchange

4 16 C t fl t

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17PERU LNG - 2009

4.16. Counter flow arrangement

Parting sheetParting sheet


Spacer barSpacer bar

Exchange finExchange fin

FlowrateFlowrate


Perforated finsPerforated fins

HeringboneHeringbonefinsfins

SerratedSerratedfinsfins

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4. Heat Exchange

4 18 Different type of distributors

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19PERU LNG - 2009

4.18. Different type of distributors

4. Heat Exchange

4 19 Different type of fins

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20PERU LNG - 2009

4.19. Different type of fins

Straight fins

Perforated fins

Serrated fins

Heringbone

fins

4. Heat Exchange

4 20 General view of the heat exchanger

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21PERU LNG - 2009

4.20. General view of the heat exchanger

--

AssemblyAssembly

--

Outlet fluidOutlet fluid

--

CoreCore

--

HeaderHeader

--

NozzleNozzle

--

WidthWidth

--

StackStack

--

LengthLength

--

PassesPasses

--

Side plateSide plate

--


--

Heat transfer finsHeat transfer fins

--

Distributor finsDistributor fins

--


--

End barEnd bar

6611

22

33

44

55

77

88

99

1010

1111

1212

1313

1414

1515

33

55

11

22

44

66

77

88

99

1010

1111

1212

11

331414 1515

4. Heat Exchange

4 21 General view of the heat exchanger

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22PERU LNG - 2009

4.21. General view of the heat exchanger

4. Heat Exchange

4 22 Warm end Embrittlement hazard

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23PERU LNG - 2009

4.22. Warm end Embrittlement hazard

Nitrogen piping at warm end of the Heat Exchanger is not

designed for cryogenic temperature

Occasionally, there can be cold f luid ingress at the warm end :

During process deviation

During stop of the plant

Precautions must be taken to prevent cold embritt lement

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1PERU LNG 2009

COLD PRODUCTIONCOLD PRODUCTIONCOLD PRODUCTION

6. Cold Production

6.1. Energy balance principle

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2PERU LNG 2009

6.1. Energy balance principle

Heat inlet

or

Cold losses

Heat losses

or

Cold inlet

APSA-L

)()( outletheatinletheat =

6. Energy Balance & Cold Production

6.2. Cold balance application

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3PERU LNG 2009

6 C pp

GAN LIN

R01 R02

D01Air

inlet

C01 K01

{

8 bar g

40C

0.1 bar g

35C

7 bar g

-171CWarmend T

Liquid

production

Insulation

losses

Turbine

work

6.3. Energy balance

6. Cold Production

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4PERU LNG 2009

gy

Cold losses or heat inlets

Heat exchanger warm end temperature difference

Liquid production

Heat entrance due to non perfect insulation

Cold inlets or heat losses

Turbine work

Isotherm expansion of products

Liquid assist

6. Cold Production

6.4. Cold balance comparison

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5PERU LNG 2009

p

Small units Large plants

Insulation

Warm end T

Liquid production

GAS LIQUID GAS LIQUID

70% 7% 20% 1%

30% 2% 80% 3%

0% 91% 0% 96%

6. Cold Production

6.5. Why a Cold Production is required ?

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6PERU LNG 2009

y q

AIM

START-UP: COOL DOWN

To ensure a decrease of the temperature in the cold box

NORMAL RUN: ENERGY BALANCE

To maintain the cold balance of the plant

HOW

By withdrawing some heat out of the cryogenic system

By expansion of air

6. Cold Production

6.6. Turbine principle

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7PERU LNG 2009

Symmetric work to the one of a centrifugal compressorSymmetric work to the one of a centrifugal compressor

Compresseur Turbine

6. Cold Production

6.7. Turbine thermo-dynamical Principle

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8PERU LNG 2009

Compressor / Pump Turbine

Theorem of Bernoulli : csteE2

VP=+

Static pressure Dynamic pressure

6. Cold Production

6.8. Turbine thermodynamical Principle

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9PERU LNG 2009

Increase in the gas speed without energywithout energy

extractionextraction in the inlet vanes (1)

static pressure diminishesstatic pressure diminishes

Decrease in the gas speed with energywith energy

extractionextraction in the relaxation wheel (2)

dynamic pressure diminishesdynamic pressure diminishes

Decrease in the gas speed without energywithout energyextractionextraction in the diffuser (3)

dynamic pressure is transformed into staticdynamic pressure is transformed into static

pressurepressure

1

2 3

6. Cold Production

6.9. Turbine overview Entrance gas process

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10PERU LNG 2009

Outinggasprocess

Turbine

body

6. Cold Production

6.10. Turbine wheels

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11PERU LNG 2009

Gas

entrance

Gas outing

6. Cold Production

6.11. Turbine wheels

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12PERU LNG 2009

Adjustable diffuser(IGV)

Wheel of the turbine

Arrival of thefluid by the

volute

Discharge

6. Cold Production

6.11. Speed tr iangle

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13PERU LNG 2009

0

1

2

0

1

2

Fixed part : Distributor

Mobile guide

vanes

Wheel

3

1U

r

1Vr

1Wr

2Ur

2Vr

2W

r

6. Cold Production

6.12. How braking cryogenic turbines ?

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14PERU LNG 2009

BrakingBraking of the turbine

Energetic stability

ConsumptionConsumption of this energy

Oil spin-dry

pump

Electrical

generator

Air

brake

Booster

brake

Oil

brake

Production of mechanical energyProduction of mechanical energy with the expansion wheel

6. Cold Production

6.13. APSA-L Oil brake turbine principle

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15PERU LNG 2009

- Figure of an oil brake -

Turbine wheel

Oiled contact surface

6. Cold Production

6.14. APSA-L cold production equipment

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16PERU LNG 2009

Air

Oil Tank

Water

Air

6. Cold Production

6.15. APSA-L PERU LNG : LIN Production Case

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17PERU LNG 2009

LRV

Turbine -19kW

19kW

S = 43000 rpm

F = 1650 Nm3/h

P = 0.2 bar g

T = -184C

F = 1650 Nm3/h

P = 4.3 bar g

T = -148C

6. Cold Production

6.16. Cryostar ECO turbine

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18PERU LNG 2009

Oil tank

Oil brake valve

6. Cold Production

6.17. Cryostar ECO turbine

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19PERU LNG 2009

Oil cooler

Oil pump

Oil tank

6. Cold Production

6.18. Turbine elements

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20PERU LNG 2009

Expander stage Oil brake sleeve in bearing housing

6. Cold Production

6.19. Expansion turbine behaviour

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21PERU LNG 2009

2 choices to increase the cold production of the plant:

increase the turbine inlet pressure of 100 mbar

decrease the turbine outlet pressure of 100 mbar

What is the best choice ?EXPANSION POWER VARIATION VS P VARIATION EITHER ON MP SIDE OR BP SIDE

15

15.1

15.2

15.3

15.4

15.5

15.6

15.7

15.8

15.9

16

16.1

0 10 20 30 40 50 60 70 80 90 100

DP (mbar)

Power(kW)

POWER BP VAR (KW)

POWER MP VAR (kW)

GAIN MP

GAIN BP

ConclusionBe careful withthe pressure on

the BP side of

the turbine.

Quick loss of cold

production

6. Cold Production

6.20. P&ID : Expansion turbine

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22PERU LNG 2009

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1PERU LNG -2009

AIR DISTILLATION

PRINCIPLE

AIR DISTILLATIONAIR DISTILLATION

PRINCIPLEPRINCIPLE

Distillation

Goal and principle

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2PERU LNG -2009

GOAL

To separate Nitrogen and Oxygen from atmospheric Air

PRINCIPLE

Separation by Distillation : Content difference between

liquid and vapour phases

KEY PARAMETERS

Boiling Point

Liquid vapour equilibrium

Fractional distillation

Reflux

WATER + ALCOHOL MIXTURE:

ALCOHOL t l til t

PRINCIPLEPRINCIPLEPRINCIPLEDistillation

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3PERU LNG -2009

LIQUID:

enriched in leastvolatil

component::

WATER

VAPOUR:

enriched in most

volatilcomponent::

ALCOHOL

BOILING

ALCOHOL: most volatil component

WATER: least volatil component

LIQUID Mixture

Two components:

WATER +ALCOHOL

APSA03/Distill1/VA#1

AIR = MIXTURE NITROGEN (79 %) + OXYGEN (21 %)

t l til t NITROGEN

PRINCIPLEPRINCIPLEPRINCIPLEDistillation

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4PERU LNG -2009APSA03/Distill1/VA#2

most volatil component : NITROGENleast volatil component : OXYGEN

LIQUID:enriched in least

volatil

component::

OXYGEN

VAPOUR:

enriched in mostvolatil

component::

NITROGEN

BOILING

LIQUID AIR

-200C, 1 b abs

At the boilling point, there are two phases:

At the boilling point, there are two phases:

Boiling Point dfinitionBoilingBoiling Point dPoint dfinitionfinitionDistillation

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5PERU LNG -2009

VAPOUR

LIQUID

P, T

- a boil ing LIQUID

- a release of VAPOUR

- a boil ing LIQUID

- a release of VAPOUR

Thus we define a

LIQUID-VAPOUR EQUILIBRIUM

Thus we define a

LIQUID-VAPOUR EQUILIBRIUM

A boiling point is defined with:

- a TEMPERATURE T

- a PRESSURE P

A boiling point is defined with:

- a TEMPERATURE T

- a PRESSURE P

Boiling point values and volatility scale

Boiling PointsBoilingBoiling PointsPointsDistillation

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6PERU LNG -2009

Boiling point values and volatility scale

Name SymbolMolecular

Weight (g)

Boiling Temperature @

1,013 bar abs.

Helium He 2 -269 C

Hydrogen H2 2 -253C

Neon Ne 20 -246C

Nitrogen N2 28 -196C

Air Air 29 -191C

Argon Ar 40 -186C

Oxygen O2 32 -183C

Kripton Kr 84 -153C

Xenon Xe 131 -108C

At the boiling point, if one parameter changes (Pressure or Temperature), the other

parameter has to change too:

Boiling PointsBoilingBoiling PointsPointsDistillation

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7PERU LNG -2009

VAPOUR

LIQUID

11 b abs

- 168 C

VAPOUR

LIQUID

1 b abs- 196 C

VAPOUR

LIQUID

3.6 b abs

- 183 C

VAPOUR

LIQUID

1 b abs- 183 C

VAPOUR

LIQUID

3.6 b abs

- 168 C

VAPOUR

LIQUID

11 b abs

- 152 C

NITROGEN OXYGEN

If the Pressure increases the Temperature has to increase too

PRESSURE AND TEMPERATURE RELATIONSHIP:

Boiling Points CurvesBoilingBoiling PointsPoints CurvesCurvesDistillation

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8PERU LNG -2009

If the Pressure increases, the Temperature has to increase tooOR

If the Temperature increases, the Pressure has to increase too

AND inversely.

Do les courbes des points dbullition:4

Pressure = f (Temperature) Temperature = f (Pressure)

Curves: Liquid state and Gaseous state separation

P

T

T

P

LiquidState

Gaseous

State

LiquidState

Consequence: the boiling point curves


GaseousState

Nitrogen versus Oxygen

Distillation Boiling PointsBoilingBoiling PointsPoints

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9PERU LNG -2009

ISOBARICISOBARICISOBARIC

NITROGENNITROGEN OXYGENOXYGEN

- 196 C

- 183 C

1 b abs

VAPOUR

LIQUID

VAPOUR

LIQUID

4.5 b abs 1.3 b abs

OXYGENOXYGENOXYGENNITROGENNITROGENNITROGEN

ISOTHERMALISOTHERMALISOTHERMAL

- 180 C

Nitrogen is more volatil than Oxygen:

-NITROGEN = most volatile component

-OXYGEN = least volatile component

Nitrogen is more volatil than Oxygen:

-NITROGEN = most volatile component

-OXYGEN = least volatile component

For an OXYGEN-NITROGEN MIXTURE at the LIQUID-VAPOUR

EQUILIBRIUM

For an OXYGEN-NITROGEN MIXTURE at the LIQUID-VAPOUR

EQUILIBRIUM

Distillation Nitrogen - Oxygen mixtureNitrogenNitrogen -- Oxygen mixtureOxygen mixture

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10PERU LNG -2009

EQUILIBRIUM,

NITROGEN being the most volatile component:

EQUILIBRIUM,

NITROGEN being the most volatile component:

OO22++NN22

OO22++NN22

P, T

(the Vapour phase and the Liquid phase are called CONCOMITANT PHASES)(the Vapour phase and the Liquid phase are called CONCOMITANT PHASES)

- the liquid phase BECOMES LESS

CONCENTRATED IN NITROGEN:

CONSEQUENTLY, IT BECOMESENRICHED IN OXYGEN

- the liquid phase BECOMES LESS

CONCENTRATED IN NITROGEN:

CONSEQUENTLY, IT BECOMES

ENRICHED IN OXYGEN

- the vapour phase BECOMES ENRICHEDIN NITROGEN

- the vapour phase BECOMES ENRICHEDIN NITROGEN

VAPOUReven more

Distillation Fractional DistillationFractional DistillationFractional Distillation

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11PERU LNG -2009

VAPOUReven more

enriched in

NITROGENNITROGEN

CONDENSER

1st BOILING

2d BOILING

VAPOUR:

enriched in

NITROGENNITROGEN

LIQUID:

enriched in

OXYGEN

Liquefaction:Liquid enriched in

NITROGENNITROGEN

VAPOUR:

"PURE" NITROGEN

N


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12PERU LNG -2009

LIQUID:

"PURE" OXYGEN

VAPOUR

MORE

ANDM

OREENRIC

HEDI

NNITR

OGEN

LIQUID

MOREAN

DMOR

EENR

ICHED

INOX

YGEN

(liquid

flowsdown

bygravi

ty)

Successive Boilings and

Liquefactions


ISOBARIC SYSTEM:

pressure is the same in each vessel

ISOBARIC SYSTEM:

pressure is the same in each vessel

-- 196196 CC"PURE" NITROGEN


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13PERU LNG -2009

-- 183183 CC"PURE" OXYGEN

pressure is the same in each vessele.g.: 1 b abs

pressure is the same in each vessele.g.: 1 b abs

CONSEQUENCE:

TEMPERATURE

GRADIENT

CONSEQUENCE:

TEMPERATURE

GRADIENT

-- 196196 CCPURE NITROGEN


SUPPRESSION OF THE BOILERS AND CONDENSERS

For that, we achieve a LIQUID-VAPOUR CONTACT:

Vapour:

HOTTER

Distillation LIQUID VAPOUR CONTACTLIQUIDLIQUID VAPOUR CONTACTVAPOUR CONTACT

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14PERU LNG -2009

LIQUID

(colder)

VAPOUR

(hotter)

Boil ing of the LIQUID =

VAPOUR

Liquefaction of

the VAPOUR =

LIQUID

LIQUID VAPOUR CONTACT

Heat Transfer

(calories)

,the Vapour passes through the Liquid in the vessel

- the vapour HOTTER, makes the liquid boiling

- the liquid COLDER, condenses the vapour


Liquid:

COLDER

LIQUID-VAPOUR

Contact

SUPPRESSION OF THE BOILERS AND CONDENSERS

Distillation LIQUID VAPOUR CONTACTLIQUIDLIQUID VAPOUR CONTACTVAPOUR CONTACT

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15PERU LNG -2009

TEMP

ERATU

REGR

ADIEN

T:

Vapouri

shott

er

Liquid

iscolde

r

We only need:

One boiler at the bottom

One condenser at the top

We only need:

One boiler at the bottomOne condenser at the top

BOILER

CONDENSER

CONDENSER

MOST VOLATILE

Distillation Fractional Distillation : ColumnsFractional Distillation : ColumnsFractional Distillation : Columns

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16PERU LNG -2009

BOILER:

Vaporizer

VAP

OUR

BECOMESR

ICHER

IN

MOSTV

OLATILE

COM

PONENT

L

IQUID

BECOMESR

ICHER

IN

LEAST

OLATILE

CO

MPONENT

LIQUID-VAP

OUR

CONTAC

T

LIQUID-VAP

OUR

CONTAC

T

DISTILLATION

COLUMNS:

DISTILLATION

COLUMNS:

TRAYSTRAYS

PACKINGPACKING

COMPONENT

LEAST VOLATILECOMPONENT

LABORATORY

Device

LABORATORY

Device

CONDENSER

Distillation Regular ColumnRegular ColumnRegular Column

GAN

Condenser

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17PERU LNG -2009

VAPORIZER

GOX DRAW-OFF

LOX DRAW-OFF

LIN DRAW-OFFGAN DRAW-OFF

AIR FEED

VAPOUR

LIQ

UID

=REFLUX

PACKING

SECTIONS

AIR

LIN

GOX

Vaporizer

LOX

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FOR A GAS NITROGEN PRODUCTION, ONLY THE UPPER

SECTION OF THE COLUMN IS NECESSARY:we do not need the lower section

From the regular column to the APSAFromFrom thethe regularregular columncolumn to the APSAto the APSADistillation

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19PERU LNG -2009

CONDENSER

VAPORIZER

GOX DRAW-OFF

LOX DRAW-OFF


AIR FEED

VAPOUR

LIQ

UID

we do not need the lower section

CONDENSER

AIR FEED


From the regular column to the APSAFromFrom thethe regularregular columncolumn to the APSAto the APSADistillation

EQUIPMENTS NEEDED

CONDENSER

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20PERU LNG -2009

EQUIPMENTS NEEDED:

- PACKING SECTION

- CONDENSER AT THE TOP

- AIR FEED IN GASEOUS STATE

- GAN DRAW-OFF

- LIQUID WASTE OUTLET

AIR FEED

GAN DRAW-OFF

PACKING

SECTION

Air feed must be in gaseous state,in order to build-up the

up-coming vapour:so that the vaporizer is

no longer necessary

LIQUID WASTE

OUTLET

INCOMING MATERIAL QUANTITY= OUTGOING MATERIAL QUANTITY

INCOMING MATERIAL QUANTITY= OUTGOING MATERIAL QUANTITY

Distillation Material BalanceMaterial BalanceMaterial Balance

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21PERU LNG -2009

400 Nm3/h THE LIQUID WASTE IS THE

CONSEQUENCE OF THE MATERIAL

BALANCE:

Flowrate, O2 content

ITS O2 CONTENT IS ALWAYS HIGHER

THAN THE ONE OF AIR;

For that, this liquid is called:

RICH LIQUID

THE LIQUID WASTE IS THE

CONSEQUENCE OF THE MATERIAL

BALANCE:Flowrate, O2 content

ITS O2 CONTENT IS ALWAYS HIGHER

THAN THE ONE OF AIR;For that, this liquid is called:

RICH LIQUID

Flowrate = 1000 - 400 = 600 Nm3/h

O2 = = 35 %600

1000 x 21 %

1000 Nm3/h

O2 = 21 %

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DEFINITION: Heat quantity necessary to vaporize totally

1 kg of liquid

DEFINITION: Heat quantity necessary to vaporize totally

1 kg of liquid

Distillation LATENT HEAT OF VAPORIZATIONLATENT HEAT OF VAPORIZATIONLATENT HEAT OF VAPORIZATION

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23PERU LNG -2009

1 kg

Liquid

1 kg

Vapour

Heat quantity: kcal

OXYGEN: 51 kcal (-183 C, 1 b abs)

NITROGEN: 47.6 kcal (-196 C, 1 b abs)

OXYGEN: 51 kcal (-183 C, 1 b abs)

NITROGEN: 47.6 kcal (-196 C, 1 b abs)


OBJECTIVES:

To liquefy gas nitrogen at the topof the column in order to achieve

CONDENSER

Distillation Vaporizer - Condenser systemVaporizerVaporizer -- Condenser systemCondenser system

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24PERU LNG -2009

PRINCIPLE:

We need a specific device to draw-off the connecting heatquantity from gas nitrogen.

GAN LIN

Heat quantity

DRAWN-OFF

of the column in order to achieve

the Reflux.LINGAN

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Vaporized

RICH LIQUID

VaporizedRL RLHeat

TRANSFER

Upper part

Distillation Vaporizer - Condenser systemVaporizerVaporizer -- Condenser systemCondenser system

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26PERU LNG -2009

LIN

GAN

EXCHANGER

GAN LINTRANSFER

APSA column

RICH LIQUID

bath

AN EXCHANGER IS LOCATED AT THE TOP OF THE COLUMN

IN ORDER TO ACHIEVE THE HEAT TRANSFER BETWEEN

RICH LIQUID AND GAN

VAPORIZER CONDENSER

VAPORIZED RICH LIQUIDRICH LIQUID

VALVE

Distillation APSA column : final constructionAPSA column : final constructionAPSA column : final construction

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27PERU LNG -2009

VAPORIZER - CONDENSER

GAN DRAW-OFF

GASEOUS AIR

RICH LIQUID BATH

BOTTOM RICH LIQUID

E02

K01

RICH LIQUIDPIPE

Distillation Reflux Ratio R : definit ionReflux Ratio R : definitionReflux Ratio R : definit ion

L

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28PERU LNG -2009

AIR

GAN

RL

V

L

Where:

V = Vapor Flowrate (Nm3/h)

L = Liquid Flowrate (Nm3/h)

R =L

V

R = LV

Distillation Reflux Ratio R : definit ionReflux Ratio R : definitionReflux Ratio R : definit ion

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29PERU LNG -2009

V L

AIR

GAN

LR

GAN

AIR

V

Where:

L = V GANand

V = Air

Consequently, R = f (GAN & Air flow rates) :

R =Air GAN

Air

Incomming

N2 amount

Outgoing

N2 amountL/V

Air GAN RL Total

Distillation Reflux Ratio R variationReflux Ratio R variationReflux Ratio R variation

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1000x79% =

790

400x100% =

400

600x65% =

390 790390/790=

0.49

1000x79% =

790450x100% =

450390 840

340/790=

0.43

The column becomes less concentrated inNitrogen :

Consequently, the column becomes enriched in

Oxygen

The GAN purity decreases (O2 content

increase)

The GAN purity decreases (O2 content

increase)

AIR

GAN

LR

Distillation Conclusion : Reflux Ratio impactConclusion : Reflux Ratio impactConclusion : Reflux Ratio impact

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31PERU LNG -2009

AIR

GAN

RL

V

L GAN

R = L/V

% N2 GAN(GAN Purity)

TECHNOLOGY : Packing elementTECHNOLOGY : Packing elementTECHNOLOGY : Packing elementDistillation

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32PERU LNG -2009

AST (Advanced Sieve Trays)

Benefits :

Very efficient liquid vapour contact

Low pressure drop (liquid film distribution)

High operating flexibility (minimal / maximal gas load)

High capacity (maximal gas load)

Low inertia

Distillation TECHNOLOGY : Packing elementTECHNOLOGY : Packing elementTECHNOLOGY : Packing element

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33PERU LNG -2009

Structure: assembly of corrugated metallic sheets (aluminium).

The Liquid-Vapour contact is obtained bythe division of the liquid on the

corrugated-crossed sheets: the liquid f ilm

Distillation TECHNOLOGY : Packing elementTECHNOLOGY : Packing elementTECHNOLOGY : Packing element

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34PERU LNG -2009

Corrugated-

crossed aluminium

sheets

Perforations

corrugated crossed sheets: the liquid f ilm

is drawn downwards by gravity while the

gas (vapour) flows upwards through the

perforations and the void spaces between

the sheets.

Distillation VaporizerVaporizerVaporizer

GOAL

to condense gas at the top of the disti llation column in

Vaporizer - Condenser

VaporizerVaporizer -- CondenserCondenser

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35PERU LNG -2009

PRINCIPLES

Heat exchange in an aluminium brazed Heat ExchangerCounter flow arrangement

Heat flux from the Hot fluid to cold fluid

Driving force = temperature difference

AIR

GAN

LR

to condense gas at the top of the disti llation column in

order to ensure a liquid reflux in the column

to vaporise Rich liquid fluid at a lower pressure in order to

feed the turbine (APSA L/LE) or the booster (APSA LE)

E02 Vaporizer

VaporizedRICH LIQUID

TECHNOLOGY : Bath type vaporiser

KEY COMPONENT FOR THE PRESSUREMAP AND FOR THE COLD PRODUCTION

Distillation VaporizerVaporizerVaporizer

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36PERU LNG -2009

-172C

4.8b

-170C

9.7b

Incondensable

gases

APSA column

RICHLIQUID

bath

SAFETY : in all cases the vaporiser must

be completely submerged

LIN

GAN

EXCHANGER

T= 2C

RL

RL + VRL

GAN

GAN

LIN

LIN

AIR downstream the Air Purification still Contents some contaminants:

Distillation Vaporizer deconcentration purgeVaporizerVaporizer deconcentrationdeconcentration purgepurge

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HYDROCARBONS

N2O

A PART OF THESE COMPONENTS ARE STOPPED IN THE

PURIFICATION UNIT

THE OTHER PART ENTER IN THE COLD BOX

The light components go up (ex: H2

,)

The heavy component go within the vaporiser bath (RL)

AMONG THESE HEAVY COMPONENTS, SOME ARE NOT VAPORISED

Distillation Vaporizer deconcentration purgeVaporizerVaporizer deconcentrationdeconcentration purgepurge

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CONCLUSION : WITHOUT ANY PURGE IT COULD HAPPEN AN

ACCUMULATION OF HYDROCARBONS WHICH CAN FORM

EXPLOSIVE COMPLEXES WITH RICH LIQUID BATH

TO AVOID ACCUMULATION, THE BATH MUST BE PURGED

PERMANENTLY

DECONCENTRATION PURGE :

DIRECTLY LINKED TO THE SAFETY OF THE PLANT

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MASS BALANCEMASS BALANCEMASS BALANCE

)()( outletinlet =

7. Mass balance

7.1. Mass balance formula

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)()( outletinlet

GLOBAL MASS BALANCE

inlet flowrate = outlet flowratePARTIAL MASS BALANCE

inlet flowrate,i = outlet flowrate,i inlet N2 flowrate = outlet N2 flowrate

APSA LAPSA L

GANGAN


AIRAIR

7. Mass balance

7.2. Mass balance application

Residual GasResidual GasGLOBAL MASS BALANCE

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3PERU LNG 2009

APSA LAPSA L

GANGAN


AIRAIR

QAir = QRes + QGAN

whereQAir = inlet air flowrate

xAir = inlet air Nitrogen composition

PARTIAL MASS BALANCE

QN2,Air = QN2,Res + QN2,GAN

xAir.QAir = xRes.QRes + xGAN.QGAN

7. Mass balance

7.3. Mass balance exercise


A customer want to produce N2 ata purity of 1ppm O2.

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4PERU LNG 2009

APSA LAPSA L

GANGAN


AIRAIR

He wants to use his air network

producing 4000 Nm3/h.

A classical O2 content in the

Residual gas is 30 % for such a

plant.

Argon is not considered in the

calculation

Air composition :78.11 % N2, 0.93% Ar, 20.96% O2

How much Nitrogen he will produce in these conditions ?

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1PERU LNG 2009

OVERVIEW OF APSA L

CONTROL

OVERVIEW OF APSA LOVERVIEW OF APSA L

CONTROLCONTROL

9. Process Flow Diagram : Warm Skid

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9. Process Flow Diagram : Cold Box

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3PERU LNG 2009

9. Process Flow Diagram : LIN Storage

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4PERU LNG 2009

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1PERU LNG - 2009

GENERAL SAFETYGENERAL SAFETYGENERAL SAFETY

Safety issues on APSA-L

General Safety Issues

General hazards in industrial environment

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Hazards specific to ASU

CnHm related hazards

Identification

Prevention

General Safety Rules

What kind of risks ?

Running machines

Electricity

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Pressure

Noise

Under-oxygenation (Anoxia)

Over-oxygenation

Cryogenic temperaturesHigh temperatures

Burning

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Example: Pressure hazard (continued)

PIPING AND

CONTAINERS COMPLIANT

WITH CURRENT REGULATIONS

ALWAYS MAKE SURE

THERE IS ZERO PRESSURE

BEFORE SERVICE OPERATIONS

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5PERU LNG - 2009

SAFETY DEVICES

OBSERVE SERVICE OPERATION

PROCEDURES

REPORT ANY DEFECT

OBSERVED ON A DEVICE,

A PIPE

OR SAFETY PART

IMMEDIATELY

SAFETY

MEASURES

-> Design codes

-> Scheduled inspections

-> Tests

32


Usual Hazardous works :

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6PERU LNG - 2009

Work at high levels

Digging work

Hoisting and handling equipments

Traffic

Electricity

Machines

Work on piping or vessel

WeldingSources of radioactivity


Safety Management

Defining clearly responsibilities

Approvals and qualifications

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7PERU LNG - 2009

Qualified and trained workers

Qualified subcontractors

Procedures

Work permit

Electrical / Mechanical isolation

Equipments

PPE

Certified tools / machinery

EIS Management?


Usual Personal Safety equipment

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Helmet

Safety glasses and adequate face shields for specific

hazards (chipping, acid work, welding, molten metals )

Ear plugs and noise-proof head sets

Safety shoesClean and Fire-proof clothing

Safety mittens or gloves

Protective masks with suitable filterSafety belt or harness if necessary

ASU Related Safety

Gas Hazards

Processed gases of ASU involve 2 main specific hazards

1) Inflammation or explosion

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9PERU LNG - 2009

Inflammation or explosion

Causes

Presence of flammable gas in air

Oxygen enriched atmosphere (more than 21% oxygen)

Concerned zones

liquid oxygen filling station oxygen expansion valve station

oxygen metering station

liquid or gaseous oxygen vent

) p

2) Anoxia

O2 gas hazardPROPERTIES .GAS ENABLES AND MAINTAINS COMBUSTION.

SAFETY MEASURES

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WITH AIR

After

analysis

if O = 21%2

DETECTION

No

leaks

O %O %22

O %O %22

IDENTIFICATION

of pipes andstorage locations.

NAMECOLOUR

Purge venting

to the outside

O2 gas hazard (continued)OXYGEN O 22

PERCEPTION

DENSITY/AIR

Colourless, odourless, tasteless.

d = 1.1AIR SPECIAL

PRECAUTIONS

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11PERU LNG - 2009

EFFECT OF OXYGEN ENRICHMENT

ON COMBUSTION

Fuels ignite more easily.

Flames much hotterand spread more quickly

NORMAL PROPORTION IN AIR 21%

PRECAUTIONS

Detection with alarm if %

O in air exceeds 25%.

No grease, no oil.

No particles.

Clean clothing made from

fire resistant textiles-

Controlled speed

with slow manoeuvres.

Floors clean and made from

non combustible materials.

% O in air2

Effect on combustion

25%25%

30%30%

50%50%

FASTER COMBUSTION

QUICK COMBUSTION

INSTANTANEOUS COMBUSTIONEXPLOSIONEXPLOSION

2

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N2 gas hazard

PROPERTIES

18% O

21% ONormal breathing

Vertigo,

headaches

Asphyxia

GAS DOES NOT SUPPORT LIFE.

WHEN THESE GASES ARE PRESENT:THE QUANTITY OF O DECREASES,

ATMOSPHERE UNDER OXYGENATED,2

2

2

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13PERU LNG - 2009

WITH AIR

SAFETY MEASURES0% O

,

ASPHYXIA.

2

orAfter

analysisif O = 21%2

If O < 18%2

DETECTION

Alarm

if O

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14PERU LNG - 2009

Effects

Every touch with liquefied gas causes frostbite similar to burnSkin and lungs can be damaged by cold atmosphere

Lower the temperature, longer the touch, more serious effects are

Hypothermia can cause death Safety rules

Do not touch cold material

Do not stay in a cold atmosphere

Do not walk in a zone where cryogenic liquid has flown

Do not purge voluntarily cryogenic liquids on the ground

Take care of wet clothes

ASU Related Safety

Operating in Heat Insulated Area

Perlite Insulation (cold box, exchanger box)Perlite : hydrated silicate pre-submitted to an expansion

Highly irritant material to be handled with gloves, glasses

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15PERU LNG - 2009

Highly irritant material to be handled with gloves, glasses

and maskExtremely light and fluid (a fall in perlite lead to death)

Rock-wool insulation (cold tank, exchanger box)

Highly itching material

Work in a tunnel highly dangerous (risk of collapsing)

Nearly all heat insulated area are considered CONFINED

SPACE specific entry rules apply

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1PERU LNG 2009

HYDROCARBONS SAFETYHYDROCARBONS SAFETYHYDROCARBONS SAFETY

Hydrocarbons Safety

1. CnHm Hazards: Explanations1. Risks related to the impurities in the bath type vaporizers

2. Right/wrong operation of the E02 vaporizer

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g g p p

3. Right/wrong operation of the front end purification (FEP)

2. Hazards Controls:The 8 Golden Rules

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Hydrocarbons Safety

Bath type vaporizer operation (APSA-L)

InternalInternal type (main vaporiser E02)type (main vaporiser E02)

LP

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4PERU LNG 2009

Important RECIRCULATION of l iquid(thermosiphon effect):

- around 1 Nm3 vaporised *

- for 50 Nm3 of non-vaporised LR *

* figures corresponding to an exchanger

completely immersed

Rare gases purge

Ne, He, H2

LP

HP

LR Purge

GAN & LIN Prod.

LRV

Hydrocarbons Safety

Proper and Wrong operation of a bath type vaporizer

Liq = 25 Nm3/h

N2O = 160 ppm

Gas = 100 Nm3/h

N20 =100 ppb

Reduced feedNormal operation

Gas = 100 Nm3/h

+

Liq = 5000 Nm3/h

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5PERU LNG 2009

Heat to vaporise 100

Liq = 5100 Nm3/h

N20 = 40 ppm

q

N20 = 41 ppm

Liq = 125 Nm3/h

N20 = 40 ppm *

* considering CO2 in that case, only 1 ppm in

the feed would lead to deposit

Heat to vaporise 100

DEPOSIT N2O

Hydrocarbons Safety


CORRECT VAPORISATION DRY VAPORISATION

GAS LIFT

STOPPED

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6PERU LNG 2009

Gas lif t in

normal

operation.Recycling

= up to

50 times

the vaporised

flowrate

Solubility limit is

reached. Deposits of

CnHm, CO2 or N2O

are

building up

Concentration is

increasing

TOO LOWLEVEL

Hydrocarbons Safety


DISTILLATION after plugingof a channel in the vaporiser

Pluging by solid :

- suspended sol ids

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7PERU LNG 2009

p

(aerosol of oi l - dust of

adsorbent)

- dissolved impurities

CO2, N2O after

reaching the solubility

limit.

Then concentration

in liquid impur ities

(CH4 - C3H8 - C2H6)

Hydrocarbons Safety


Normal Operation:

Excess liquid flowing out

No concentration

Dry Boiling:

No liquid out

Concentration build up

Deposit starts if liquid

gets saturated and

Contaminants cannot be

eliminated wi th the gasNormal level

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8PERU LNG 2009

phaseNormal level

Low level Low level

Hydrocarbons Safety Application: APSA-L E02 Vaporizer

LRV

CnHm enter CnHm exit

VAPO

E02ININ Q

LRVLRV Q

LRLR Q

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9PERU LNG 2009

LR

LR

AIRAIR

LRLRV

AIRAIRLR

Q

Q

QQK

Q =

+

Q

Purge Rate = 0.2% of AIR FLOW

Concentration factor = 500Air content LOX content

CH4 = 5 ppm CH4 = 2500 ppm

C2H6 = 0.2 ppm C2H6 = 100 ppm

C2H2 = 0.5 ppm C2H2 = 250 ppm

Purge Rate = 0.2% of AIR FLOW

Concentration factor = 500Air content LOX contentCH4 = 5 ppm CH4 = 2500 ppm

C2H6 = 0.2 ppm C2H6 = 100 ppm

C2H2 = 0.5 ppm C2H2 = 250 ppm

PI4.2 barg

Hydrocarbons SafetyAdsorption Principles

The Front End Purif ication (FEP)is designed to stop completely :

H2O

CO2

H2O and CO2free air

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10PERU LNG 2009

CO2

But other impurities

from the air pass through

the adsorber before CO2 :

CH4 Methane

C2H6 Ethane

C3H8 Propane

N2O Nitrous Oxide

C2H4 Ethylene

Air with all

contaminantsREACTIVATION

ADSORPTIO

N

And may enter into the Cold BoxAnd may enter into the Cold Box

Hydrocarbons SafetyAdsorption capacity of Front End Purification

aton

aton

totalH2O, CO2,

nC4H10, C2H2, O3.

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Frontend

Frontendpurific

a

purifica

partial

none

N2O, NO2,

C2H4

ADSORPTIONADSORPTIONLEVELSLEVELS

C3H8,

NO

H2, CO,H2, CO,

CH4, C2H6CH4, C2H6

Hydrocarbons Safety Contaminants dangerous for the purif ication

Some CONTAMINANTS can badly damageSome CONTAMINANTS can badly damage

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They are mainly:They are mainly:

-- the acid gases : CI2, SO2, H2S etc., NH3the acid gases : CI2, SO2, H2S etc., NH3

-- miscellaneous organic moleculesmiscellaneous organic molecules

the molecular sievesthe molecular sieves

Hydrocarbons Safety Potential hazards in the Front End Purification

Abrasion of a part of the adsorbent (velocity too high)

Risk of channeling = by pass flow

Risk of lower adsorption capacity

Risk of introducing adsorbent dust in the cold box

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Internal bypass of the beds, by leakage Liquid water carry-over (separation problem) :

CO2 adsorption capacity is reduced if water vapor reaches the molecular

sieve

A part of the adsorbent can be destroyed Presence of some aerosols which go through the FEP

Presence of dangerous contaminants in the mole sieve

Too long adsorption phase :

break-trough of CO2 or H2O

Example of CO2 entering an APSA L4 :

-10 ppb of CO2 entering continuously : 2 kg per year

-2 ppm of CO2 during 15 minutes : 15 grams of deposit

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Hydrocarbons Safety Event sequence to explosion

Spontaneous ignition of reactive

material on Aluminum platefin

main vaporizer in cold box

Explosive rupture of

cryogenic distillation

column

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Presence of airborne fuel

- aerosols light hydrocarbons -

concentration/accumulation in

LOX & on Aluminum surfaces -

with N2O or CO2 ice & dry-boiling

Combust ion of accumulated

hydrocarbon contaminants

on Aluminum vaporizer cores

Massive runaway combustion

of Aluminum exchangers inoxygen (exothermic reaction)

Flash vaporization

of cryogenic liquid

Uncontrolled escalation

to explosion

Hydrocarbons Safety Risks related to the impurities in the vaporizers

During the operation of the ASU, the concentration of impurities in the bath ofthe vaporiser may lead to strong explosions :

- Hydrocarbons, such as Ethane, Propane, Ethylene, Acetylene, or aerosols, can

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concentrate and/or deposit. The Lower Inflamability Limit is reached in LOX- Ozone is a strong ignition agent

These explosion hazards exist when there is a lack of LOX (LR) feed into the

passages, caused by :- Too low level of the bath of the vaporiser

- Plugging of passages by solid deposits: CO2* , N2O*, dust...

* Risk of accidental deposit of CO2 or N2O, due to their low solubility in LOX,5 ppm and 160 ppm respectively.

Hydrocarbons Safety Possible Damage Overview

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Hydrocarbons Safety How to control the CnHm hazards

The 8 GOLDEN RULES1. Environmental Survey

2. Operation of FEP

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18PERU LNG 2009

3. Operation of Vaporizer4. Deconcentration purge

5. Periodical Deriming

6. Control of the transient phases

7. Control of other sources of pollution

8. EIS management

Hydrocarbons Safety

1. Environmental Survey

1. Surrounding industries and distances

2. Atmospheric conditions

3. Air analysis

4. Communication with surrounding industries

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19PERU LNG 2009

g

The plant operator shall maintain an environment

file including following information :

Nearby industries liable to release gases

Distances between those potentials sources and theair intake of the ASU (+ height of sources)

Presence of haze (organic aerosols)

Polluted site or Not ?

Hydrocarbons Safety

2. Operation of FEP

Complete retention of CO22 in FEP is of vital importance forthe unit (low solubility in RL : 5 ppm at 181C)

Air conditions evolutions have an impact on :

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Mass Flow RatePressure

Temperature

Duration of the adsorption

Air Cleanliness

Regeneration conditions act on :

Regeneration gas flow rate

Duration of heating

Heating temperature

Hydrocarbons Safety

2. Operation of FEP

FEP performance control : CO22 content analysis at outlet1 ppm Alarm

3 ppm Shutdown of the unit after 15 minutes

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Control of the desorption effectiveness : temperature peak

Alarm in case of no heat peak

Recommended REGEX operation after CO2 breakthrough

test (3 years)

Hydrocarbons Safety

3. Control of the level of bath vaporizer

Upper level tap (100%of the transmitter scale)

Level sample

100% immersion (Level Set Point)LT2

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Lower level tap for LT1

90% immersion (Low Level Threshold)80% immersion (Very Low Level Threshold)

0% immersion

(0% of LT1)

LT170% Lower tap of LT2

Calibration using the heights and the density of the liquid

Check with level sample gaugeTransmitters:

22ndnd

transmittertransmitter= improvement= improvement

Height,m

Plant Shutdown after 1 hour

Hydrocarbons Safety 4. Deconcentration Purge

Deconcentration line: 1/2.LR.04

Deconcentration type: intermittent purge (but permanently

in service)

Deconcentration volume: at least 0.2% of the air flow

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Deconcentration control: sequence linked to the level of

vaporizer E02

Time of purge is constant

Level drop is monitoredAlarm is raised in case of low level drop

Hydrocarbons Safety 5. Periodical Deriming

The objective is to vaporize any contaminants which may

have entered in the equipment of the cold box

Every 3 years

Applied to cold box equipment only (compressor and FEP

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are running independently)Deriming operation

Low pressure

High flow

Deriming mean

Dry air

Usually ambient temperature

Exceptionally hot temperature (65C is the limit for thealuminum heat exchanger)

Refer to PFD

Hydrocarbons Safety 6. Transient Phases

Start-up

As much liquid production as possible

Minimum air input

Liquid assist after first liquid production (LIN only)

S

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25PERU LNG 2009

Shut-down

Drain ALL liquid after 48h shut-down

Drain if E02 level is below 80% immersion

Change of run-typeMaintain vaporizers level

Normal run

Control of frosted pipes and dead-ends

Hydrocarbons Safety 7. Other sources of pollution

Machine: Turbine

Lubricated machine

Seal gas pressure

Instrument air

U ll d i

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26PERU LNG 2009

Usually: dry air

Back-up ?

Air intake

Car parking, Truck unloading

Hot works, fires...

Exchanger water leak...

Hydrocarbons Safety 8. E.I.S Management

E.I.S = Element Important for Safety

Safety Protection Loops

Alarm and Shutdowns parameters

Set-points

D l

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Delay Hysteresis

Qualified personnel

Management of Change

Hydrocarbons Safety Conclusions

Hazard is a combination of

A polluted atmosphere

A not proper operation of the vaporizer

Hazard is a combination of

A polluted atmosphere

A not proper operation of the vaporizer

C l d t id t

C l d t id t

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28PERU LNG 2009

THE GOLDEN RULES

1. Environmental Survey2. Operation of FEP

3. Operation of Vaporizer

4. Deconcentration purge

5. Periodical Deriming

6. Control of the transient phases


8. EIS management

THE GOLDEN RULES

1. Environmental Survey

2. Operation of FEP

3. Operation of Vaporizer

4. Deconcentration purge

5. Periodical Deriming6. Control of the transient phases


8. EIS management

Can lead to severe accidentsCan lead to severe accidents

DERIMINGDERIMINGDERIMING

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1PERU LNG 2009

DERIMINGAND

EXCEPTIONAL REGENERATION

DERIMINGDERIMINGANDAND

EXCEPTIONAL REGENERATIONEXCEPTIONAL REGENERATION

1. Deriming Procedure1. Deriming Procedure Deriming and Drying Procedure

PurposeRemove contaminants in every locations they are subject to

accumulate

Accelerate to warm up of the plant after a shutdown

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2PERU LNG 2009

Main recommendations

All liquids should be completely purged before starting deriming

Start deriming with all valves closed

6 phases in order to defrost progressively the plant

Proceed from a clean circuit towards a dirty circuit

Use the lowest pressure possible

Keep the deriming outlets wide open

Control the deriming flow rate in order to avoid high velocities

1. Deriming Procedure1. Deriming Procedure

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1. Deriming Procedure1. Deriming Procedure

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2. Exceptional Regeneration2. Exceptional Regeneration

Purpose

Remove impurities not desorbed during regular reactivation

Exceptional procedure to avoid any damage

Carry out :

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Carry out :

At initial start-up

To clean from contaminants accumulated during transportation

To control adsorption capacity respect to design capacityAfter an pollution accident

Late reversal

Liquid water from R02

Unusual temperature at the inlet of the dryers

After repetitive CO2 break-through


Highlights

Passing dry gas at low pressure and increased temperature

Long period of time through the bottle (24 hours at least)

Temperature in the bottles may range from 230 to 290C

Temperature increase : two steps to avoid damage of

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6PERU LNG 2009

Temperature increase : two steps to avoid damage ofadsorbents

Outlet electrical heater

Bottle bottom

145C

~120C

~ 240C

290C

Phase 1 Time

Temperature

Phase 2 Phase 3 Phase 4

Effective part of

exceptional regeneration

Effective part of

exceptional regeneration


ATM

EH-6701

Instrument Air

PV 561

KV 540Deriming Air

From Exchangers

TI

580

Q(WN2) = 121 Nm3/h

P (V-6701 A) = 1.033 bar absTI 513 outlet = 240C

Q(WN2) = 121 Nm3/h

P (V-6701 A) = 1.033 bar absTI 513 outlet = 240C

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C01

V-6701 A V-6701 B

Outlet Water

Inlet Water

To Exchangers

KV 515

ATM

ATM

TI

513

AIR

PERU LNGPERU LNGPERU LNG

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1PERU LNG 2009

PERU LNGNITROGEN GENERATOR SYSTEM

TRAINING

PERU LNGPERU LNGNITROGEN GENERATOR SYSTEMNITROGEN GENERATOR SYSTEM

TRAININGTRAINING

1. Process description APSA LProcess description APSA L

2. Air Purification Unit2. Air Purification Unit2. 1 Exceptional Regeneration2. 1 Exceptional Regeneration

3. Turbine Expanders3. Turbine Expanders

4. Cold box4. Cold box warm standstillwarm standstill

NITROGEN GENERATOR TRAININGNITROGEN GENERATOR TRAINING

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5. Production5. Production

6. Trip and shutdown6. Trip and shutdown

7. Start up cold standstill7. Start up cold standstill

8. Control loop description8. Control loop description

9. Stutdown9. Stutdown

1. Process description APSA LProcess description APSA L

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PurificationCompression Heat exchange Cold production Distillation

2. Air Purification Unit2. Air Purification UnitTo start it we should do a Initialization; for this the inlet valve should be close and

the inlet pressure PT_502 at 0 bar. You choose the bottle which be in regeneration

and press initialization button. The Bottles will place in HP isolation step.

You open inlet valve FV_580 to pressurize the bottle on line and the HP cold box

Open it to have enough flow for regeneration.

You should open the KV_540 to send air in regeneration bottle and put the PV_561

in auto mode with SP at 160 mbar. When flow from cold box is enough you closeKV 540

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AIR

g yKV_540.

When the timer step is done and you have all condition, a indication Next step

appear you can move manually the sequence by Next step button

If you need to move all the sequence you have a Bypass button to bypass the

heating and cooling timer. But this dont bypass other step.

If all is correct you should put the sequence in auto mode in order to avoid CO2

breakthrough. You can open air production valve FV561 and put in auto SP 750

Nm3/h

In case of problem you must put the sequence in manual mode and check the

problem.

2. Air Purification Unit2. Air Purification Unit1. High Pressure Isolation

Isolation of the bottle in adsorption

Timer step 360s

2. Depressurization

The bottle is slowly depressurized in opposite direction to the adsorption

flow. Drop pressure of bottle should be done during step timer else we

have Depressurization to long and stop the sequence. Timer step 300s

heater

Cold Box

N2cold boxKV_540

Cold Box

N2cold box

heater

KV_540

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5PERU LNG 2009

KV_520KV_510

KV_526KV_516

KV_525KV_515

KV_530

venting

V-6701A V-6701B

Hp isolationIn service

Ai r

KV_520KV_510

KV_526KV_516

KV_525KV_515

KV_530

venting

V-6701A V-6701B

Hp isolationIn service

Ai r

2. Air Purification Unit2. Air Purification Unit3.Blow-off

Start to send flow thought the bottle. We should have

minimum 8 mbar of DP on heater else Alarm EH-6701

Heater low flow. Timer step 60s

4.Heating

The heater starts to increase temperature at around 150C

In case of the outlet temperature is always < 135c after 15 min Alarm Heater

start fault Timer step 45mn

Cold Box

N2cold box

heater

KV_540

Documents

157883-000-CG-VT-0001