Designing Internals to Minimize Fouling in the Bottom of ... · YORK ® separations ... RATEFRAC® software, SCHEIBEL ... SMV extraction packing, SMVP extraction packing, SPEED-WAY

© 2018 Koch-Glitsch, LP. All rights reserved.

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Dennis Schmude

Designing Internals to Minimize Fouling in the Bottom of FCC Main Fractionators


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FCC Main Fractionator

GAS OIL FEED

LCO

Slurry

HCO

TO FCC GAS PLANT

FCC NAPHTHA

Reactor Effluent

FCC Reactor

FCC Wet Gas Compressor

Spent CatalystSteam

FCC UnitSimplified Flowsheet

HCO Wash Zone

Slurry PA Zone


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Bottom Section Fouling

A

B

C

D


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Fouling Symptoms

Hydraulic flooding– High DP– Unstable operation– Reduction in throughput

Loss of efficiency– Poor slurry PA heat transfer– Poor wash section performance


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Preventing HCO Wash Section Fouling

Maintain adequate temperature

Maintain and control adequate wash rates

Design for high reliability, not high efficiency

Eliminate wash section for severe cases (if possible)


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HCO Wash SectionTrays

Large size, high lift fixed valve units (PROVALVE® trays)– Avoid floating valve units– Avoid small valve units– Consider directional valve units

Minimize number of flow passes– Maximizes downcomer clearance

Avoid utilizing an excess number of trays


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HCO Wash SectionPacking

Sheet Metal Structured Packing

Traditional Grid New Grid Packing(Large Crimp)

New Grid Packing(XL Crimp)

Packing Type/Size FLEXIPAC® 3YS FLEXIGRID® 3-45 PROFLUX® 64 PROFLUX® 45

Nominal Thickness 0.008” 0.06” 0.04” 0.04”

Nominal Surface Area (ft2/ft3) 34 14 20 14

Fractionation Efficiency Best Fair Good Fair

De-entrainment Removal Efficiency Best Fair Good Fair to Good

Fouling Resistance Moderate Good Good Excellent

Clean & Reinstall No Yes Yes Yes


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HCO Wash SectionPacking

Proper packing selection for efficiency needs– Structured packing vs. grid packing– Most units do not take an HCO side

cut product

Utilize short packing depth (less than 1 stage)– 3 to 4 ft of grid type packing suitable for

most units

Proper liquid distributor selection for efficiency needs


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HCO Wash Bed Distributor Comparison

Liquid Distributor Type Spray Nozzle Trough (Gravity)Drip Point Baffle

Feed Point Density 0.06 7 - 9 3 – 4No. of Feed Points 19 2500 1100Distributor Opening Size 0.343” 0.09” 0.14”

Nominal Liquid Velocities 3 – 5 ft/s < 0.1 ft/sResidence Time 8 - 10 sec Parting box – 30 sec

Troughs – 120 sec

Liquid Distributor Quality Low HighCoverage at Top of Bed Excellent Some dry areas initiallyWash Entrainment Risk High Low

Example: 20 ft ID Fractionator, 5,000 BPD wash (0.6 gpm/ft2)


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HCO Wash to Slurry PA Transition

SLURRY PA

HCO WASH

No liquid collection device

Slurry PA Bed

HCO Wash Bed

HCO Draw Tray


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HCO Wash to Slurry PA Transition

Distribution/mixing of wash liquidis important


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Baffle Trays for Slurry PA

Sheds Disc & Donut


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Slurry PA Grid Packing Selection

Traditional Grid New Grid Packing(XL Crimp)

Packing Type/Size FLEXIGRID® 2-45 PROFLUX® 40X

Nominal Thickness 0.06” 0.04”

Nominal Surface Area (ft2/ft3) 14 13

Fouling Resistance Good Excellent

Hydraulic Capacity High Very High


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Fouling Resistance

FLEXIGRID® 2-45 grid PROFLUX® 45 grid


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Liquid Distributor for Slurry PA


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Liquid Distributor for Slurry PA


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Slurry PA After Catalyst Carryover Event

A

B C


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Liquid Distributor Features

Feed notch shape

Elevated vs non-elevated feed notches

Feed pipe and parting box predistribution

Parting box metering to troughs– Large holes vs side notches

Beam supported design


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Bed Support and Hold Down System

Hold down system should not block liquid from distributor system

Eliminate/minimize horizontal surfaces– Free flow support ring– Special beam designs for large diameter towers


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Feed InletGas Distribution

Most common and reliable configuration is to utilize no vapor distribution device

Some units may warrant utilizing a vapor distribution device in the following situations:– Packed slurry PA– Excessive inlet nozzle velocities– Inadequate space from gas inlet to bottom of bed

Conventional vapor distribution devices are not suitable to handle fouling


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CFD Model StudyGas Distribution

No Feed Device With Feed Device

m/s m/s


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Conclusions

Packing in the bottom sections is common

Very fouling service

Typical FCCU lengths are achievable with proper selection and design of internals

Improvements in equipment hardware available– Especially compared to units with internals designs that are

15 years or older


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Thank you.

Questions?TRADEMARKSThe following trademarks are owned by Koch-Glitsch, LP in the United States and may be registered in other jurisdictions: AHOP® Automated Hardware Ordering Program, BALLAST® tray, BATCHFRAC® software, Bi-FRAC® tray, CASCADE MINI-RINGS® random packing, DEMISTER® mist eliminator, FLEXICHEVRON® mist eliminator, FLEXIFIBER® mist eliminator, FLEXIGRID® severe service grid packing, FLEXILOCK® tray construction, FLEXIMAX® random packing, FLEXIPAC® structured packing, FLEXIPAC® HC® structured packing, FLEXIRING® random packing, FLEXITRAY® valve tray, GEMPAK® structured packing, GLITSCH GRID® severe service grid packing, GOODLOE® mesh structured packing, HORIZON® technology, HY-PAK® random packing, IMTP® random packing, INTALOX® Packed Tower Systems technology, INTALOX PACKED TOWER SYSTEMS WITH PROCESS TOWER L® (logo). INTALOX® structured packing, INTALOX® SNOWFLAKE® random packing, INTALOX® ULTRA random packing, KARR® column, KATAMAX® reactive distillation structured packing, “K” KOCH-GLITSCH® (logo), KG-TOWER® software, KOCH-GLITSCH® technology, KOCH-OTTO YORK® separations technology, KY-FLEX® liquid-liquid coalescing media, MAX-FRAC® tray, MINIVALVE® tray, OMNI-FIT® technology, OTTO YORK and Design® (Football), PROFLUX® severe service grid, PROVALVE® tray, RATEFRAC® software, SCHEIBEL® column, Super INTALOX® Saddles random packing, SUPERFLUX® tray, SUPERFRAC®

tray, THE SEPARATIONS COMPANY®, TRITON® tray, and ULTRA-FRAC® tray. The following registered trademarks are owned by Koch-Glitsch, LP in the CTM countries and may be registered in other jurisdictions: BETA RING® random packing and SATURN® technology. The following trademarks are owned by Koch-Glitsch, LP in the United States and may be registered in other jurisdictions: CMR random packing, COALEX liquid-liquid coalescing media, DEMISTER-PLUS mist eliminator, ETAPAK random packing, FLEXIPEAK mist eliminator, INTALOX® ULTRA random packing, KFBE fluidized bed structured packing, KITTEL tray, KY-MESH liquid-liquid coalescing media, LUBEMAX technology, PLUS technology, PURGE downcomer, ROSEMAX structured packing, SMV extraction packing, SMVP extraction packing, SPEED-WAY manway, TYPE "D" SAFETY SCRUBBER mist eliminator housing, VARIOFLEX tray, YORK-EVENFLOW vane inlet device, YORKMESH knitted wire mesh, and YOU CAN RELY ON US. All other trademarks, service marks, or registered trademarks that appear in this document are the trademarks or service marks of their respective owners. For related trademark information, visit http://www.koch-glitsch.com/trademarks.aspx..

PATENTSThe following technologies are protected by one or more patents in the USA; other foreign patents may be relevant: Column Internals (US6722639, US6889961, US6889962, US7104529, US7114709, US7125004, US8317166, US8485504, US9089787, US9625221), Cyclone mist eliminator (US9192886), FLEXILOCK® tray construction (US6592106), FLEXIPAC® HC® structured packing (US6478290), FLEXIPEAK mist eliminator (US7905937), INTALOX® ULTRA random packing (US7722945), KFBE fluidized bed structured packing (US6224833), KITTEL® trays (US7028995), LUBEMAX technology (US6962661), Mechanical Design Enhancements (US8485504, US8944418, US9295926), Mini Bubble Promoter (USD650466), OMNI-FIT® technology (US6736378, US7055810, US7125005), PROFLUX® severe service grid (US8298412), PROVALVE® tray (US5762834), SATURN® technology (US6736378, US7125005), SUPERFLUX® tray (US5895608), SUPERFRAC® tray (US5895608), TRITON® tray (US5762834), ULTRA-FRAC® tray (US8500105, US8191870). Available exclusively from Koch-Glitsch, FLEXIPAC® HC® structured packing is protected by US Patent US6478290 and other patents worldwide assigned to Praxair Technology, Inc. Koch-Glitsch, LP is the exclusive worldwide licensee of Praxair Technology, Inc. for the manufacture and sale of this packing in all markets except for industrial gas separation.

LEGAL NOTICESThe Information in the presentation is not a guarantee of results to be achieved by any user and is not a statement of warranty, either express or implied. ALL EXPRESS AND IMPLIED WARRANTIES ARE EXPRESSLY DISCLAIMED, INCLUDING THOSE FOR MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Individual results may vary and Koch-Glitsch cannot anticipate nor control conditions of application. IN NO EVENT SHALL KOCH-GLITSCH, ITS AFFILIATES, OR ANY PARTY INVOLVED IN CREATING, PRODUCING, OR DELIVERING THIS PRESENTATION BE LIABLE FOR ANY LOSS, DAMAGE, CLAIM, FINE, PENALTY OR ANY OTHER CLAIM, INCLUDING BUT NOT LIMITED TO CLAIMS FOR CONSEQUENTIAL, SPECIAL, GENERAL, INCIDENTAL, DIRECT, INDIRECT, PUNITIVE, PERSONAL INJURY OR PROPERTY DAMAGES, INCLUDING WITHOUT LIMIT LOSS OF PROFITS, REVENUES, OR OTHER ECONOMIC LOSSES, ARISING OUT OF YOUR ACCESS, USE, OR INABILITY TO USE THIS PRESENTATION OR ANY ERRORS OR OMISSIONS IN THE CONTENT THEREOF.

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Designing Internals to Minimize Fouling in the Bottom of ... · YORK ® separations ... RATEFRAC® software, SCHEIBEL ... SMV extraction packing, SMVP extraction packing, SPEED-WAY