Molecular Sieve Applications - KLM Technology Sieve Applications PRESENTER: CHARLES D. NOLIDIN Cheah Phaik Sim Loo Yook Si ... Comparison of Breakthrough Test Parameter Mol Sieve X

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  • Molecular SieveMolecular SieveApplicationsApplications

    PRESENTER: CHARLES D. NOLIDIN

    Cheah Phaik Sim

    Loo Yook Si

    Karl Kolmetz

  • OutlinesOutlines

    Introduction - Molecular Sieve Adsorbents

    Adsorption Principles

    Dynamic Adsorption

    Regeneration Methods

    Applications in Titan

    Molecular Sieve Life and Contaminants

    Thermal Effects (Safety Aspects)

    Services Provided

    Conclusion

  • Introduction - Molecular SieveIntroduction - Molecular SieveAdsorbentsAdsorbents

    Crystalline aluminosilicate or syntheticzeolites

    Unique structure withregular pore size

  • Introduction - Molecular SieveIntroduction - Molecular SieveAdsorbentsAdsorbents

    Strong adsorptive force to remove many gasor liquid impurities to very low levels (ppmor less)

    Differ from other adsorbents in the form oftheir isotherms which have a high adsorptioncapacity for relatively low concentrations ofthe adsorbate

  • Synthesis and Preparation ofSynthesis and Preparation ofMolecular SievesMolecular Sieves

    Sodium Silicate Caustic Soda Sodium Aluminate

    Synthesis

    Ion Exchange

    Activation

    Binder

    Mixing

    Extrusion

    Activated Powder

    ActivationGranulation

    Activation

    1.6 - 3.2 mm 0.7 - 1 - 1.5 - 2 - 5 mm

  • Adsorption PrinciplesAdsorption Principles

    A phenomenon of a surface on which amolecule contained in a fluid is fixed on asurface of a solid

    Adsorption of the impurities having lowerand/or same size as the pores of themolecular sieve.

  • Adsorption PrinciplesAdsorption Principles

    When several impurities having the samesize have to be removed, the more polar ofthem is first adsorbed.

    Physisorption of the impurities (Van derWaals interaction) on the molecular sievefollowing a extended Langmuir equation.

  • Dynamic AdsorptionDynamic Adsorption

    The most common mode of adsorptiveseparation process employs a fixed bed,cyclic operation.

    Mass Transfer Zone (MTZ) is defined asthe bed length (h) through which theconcentration of the adsorbate is reducedfrom initial CO to desired CS

  • Dynamic AdsorptionDynamic Adsorption

    Water vapor is adsorbed in a finite lengthof bed (MTZ) as wet process stream entersfresh molecular sieve bed

    As wet gas continues to flow, the bed maybe divided into 3 zones, saturated(equilibrium) zone, MTZ and active (freshor regenerated) zone

  • Dynamic AdsorptionDynamic Adsorption

    When the MTZ reaches the outlet end of thebed, the bed is exhausted and regenerationis required

    The water content is shown to increase inthe breakthrough curve as the MTZ movestowards the outlet

  • Dynamic AdsorptionDynamic Adsorption

    Saturated molsieve (noadsorption)

    Fresh orregenerated molsieve

  • Regeneration MethodsRegeneration Methods

    The saturated mol sieve recovers itsadsorption capacity after desorption - this isregeneration

    Four methods available commercially:

    * Thermal swing - heating the bed to atemperature at which the adsorptive capacityis reduced to a low level

    * Pressure swing - reducing adsorptive capacityby lowering pressure at constant temperature

  • Regeneration MethodsRegeneration Methods

    * Inert purge stripping - passing a fluidcontaining no adsorbable molecules and inwhich the adsorbate is soluble withoutchanging temperature or pressure

    * Displacement desorption - passing a fluidcontaining a high concentration of anadsorbable molecule without changingtemperature or pressure

  • Applications in TitanApplications in Titan

    The necessity of water removal is toprevent any hydrates in subsequent lowtemperature equipment.

    Discussion of molecular sieves applicationin Titan will be limited to the following:-

    Cracked Gas Dryers

    Liquid Dryers

    Hydrogen Dryers

  • Cracked Gas DryersCracked Gas Dryers Process Flow DiagramProcess Flow Diagram

    Steam

    ReactivationGas Supply

    CW

    To FuelSystem

    Regeneration

    Process To HPDepropanizer

    From CG SubcoolerKnock Out Drum

    Drying

  • Cracker 1

    One vessel on drying mode and one vesselon regeneration or standby mode

    Presently, the dryer vessels are loadedwith mol sieves from two differentvendors

    Fixed adsorption cycles of 60 to 70 hours

    Cracked Gas DryersCracked Gas Dryers Operating Conditions (Adsorption Step)Operating Conditions (Adsorption Step)

  • Design operating conditions are:

    * Temperature ~ 10.5C

    * Pressure ~ 15 kg/cm2g

    * Flow rate ~ 76 ton/h

    * Water content ~ 886 ppmv

    Cracked Gas DryersCracked Gas Dryers Operating Conditions (Adsorption Step)Operating Conditions (Adsorption Step)

  • Cracked Gas DryersCracked Gas Dryers Comparison of Breakthrough Test Comparison of Breakthrough Test

    ParameterVessel A

    Mol Sieve XVessel S

    Mol Sieve Y

    Mol sieve type1/8 and 1/16

    3 1/8 and 1/16

    3

    Date of bthru test Mol sieve life of 4 months Mol sieve life of 7 months

    Feed rate 59.6 ton/h 58 ton/h

    Water content 787 ppmv 900 ppmv

    Adsorption time 83.5 hours 76 hours

    Adsorptioncapacity

    13.78 gH2O/100g molsieve

    13.92 gH2O/100g molsieve

    Mol sieve life 42 months to date 18 months to date

  • Regeneration periodof 48 hours

    Design regenerationconditions are:

    * Depressurised to 4kg/cm2g

    * Heat to bedtemperature of 200C

    * Regen gas flow rate is6 tons/h

    Cracked Gas DryersCracked Gas Dryers Operating Conditions (Regeneration Step)Operating Conditions (Regeneration Step)

    DRAINING

    WARM PURGE HEATING

    COOLING

    STANDBY

    DEPRESSURIZING

    COLD PURGE

    REPRESSURIZE

  • Cracked Gas DryersCracked Gas Dryers Typical Regeneration Curve (Mol Sieve Y) Typical Regeneration Curve (Mol Sieve Y)

    Depressurize

    Startregeneration

    48 hours Time

    Drain Purge Heat CoolRepressurize

    Stand-by250

    150

    100

    50

    0

    200

    Tem

    pera

    ture

    C

    Mol Sieve X has similar regeneration curve

  • Liquid DryersLiquid Dryers Process Flow Diagram Process Flow Diagram

    Liquid drain

    To fuel gassystem

    Depressurizingto CGC suctiondrum

    Heater

    Regen gas fromDemethanizerSystem

    Steam

    Coalescer

    Process liquidfrom CG knockout drum

    Water

    Purge gasfrom CGDryers

    Drying

    Process liquid toHP Depropanizer

    Regeneration

  • Cracker 1

    One vessel on drying mode and one vesselon regeneration mode

    Fully automatic operations by PLC

    Fixed adsorption cycles of 24 hour

    Have used mol sieves from two differentvendors

    Liquid DryersLiquid Dryers Operating Conditions (Adsorption Step)Operating Conditions (Adsorption Step)

  • Design operating conditions are:

    * Temperature ~ 10.5C

    * Pressure ~ 18.6 kg/cm2g

    * Flow rate ~ 7736 kg/h

    * Water content ~ 420 ppmw

    Liquid DryersLiquid Dryers Operating Conditions (Adsorption Step)Operating Conditions (Adsorption Step)

  • Liquid DryersLiquid Dryers Comparison of Breakthrough Test Comparison of Breakthrough Test

    Parameter Mol Sieve X Mol Sieve Y

    Mol sieve type 1/16 3 1/16 3

    Date of bthru testMol sieve life of 7

    monthsMol sieve life of 15

    months

    Flow rate 9300 kg/h 12500 kg/h

    Water content 420 ppmw 420 ppmw

    Adsorption time 36 hours 25 hours

    Adsorptioncapacity

    15.62 gH2O/100gmol sieve

    14.58 gH2O/100gmol sieve

    Mol sieve life 35 months 24 months *

    * Short run life due to different regeneration conditions

  • Regeneration periodis 24 hours

    The typical operatingconditions are:

    * Depressurised to 4kg/cm2g

    * Heat to bedtemperature of 200C

    * Regen gas flow rate is135 kg/h

    Liquid DryersLiquid Dryers Operating Conditions (Regeneration Step)Operating Conditions (Regeneration Step)

    SWITCHOVER

    HEATING COOLING

    PURGING

    STANDBY

    DRAINING

    DEPRESSURIZING

    FILLING

  • Hydrogen DryersHydrogen Dryers Process Flow Diagram Process Flow Diagram

    Frommethanatoreffluentseparator

    Drying

    H2 productsto plant

    Depressurizing tocompressorsuction drum

    Fromregenerationgas heater

    Regeneration

    Liquiddrain

    To fuel gas system

  • Cracker 2

    One vessel on drying mode and one vesselon regeneration or standby mode

    Only used mol sieves from one vendor

    Fixed adsorption cycles of 48 hours

    Hydrogen DryersHydrogen Dryers Operating Conditions (Adsorption Step)Operating Conditions (Adsorption Step)

  • Design operating conditions are:

    * Temperature ~ 12C

    * Pressure ~ 30 kg/cm2g

    * Flow rate ~ 1226 kg/h

    * Water content ~ 475 ppmv

    Hydrogen DryersHydrogen Dryers Operating Conditions (Adsorption Step)Operating Conditions (Adsorption Step)

  • Hydrogen DryersHydrogen Dryers Performance Performance

    Parameter Vessel A/S

    Mol sieve type 1/8 3

    Flow rate 1300 kg/h

    Water content 475 ppmv

    Adsorption time 48 hours

    Adsorption capacity7.59 gH2O/100g mol

    sieve

    Mol sieve life 31 months to date

  • Regeneration periodof 48 hours

    Design regenerationconditions are:

    * Depressurised to 4kg/cm2g

    * Heat to bedtemperature of 200C

    * Regen gas flow rate is600 kg/h

    Hydrogen DryersHydrogen Dryers Operating Conditions (Regeneration Step)Operating Conditions (Regeneration Step)

    DRAINING