Blended Amines

1BLENDED AMINES

By: Charalambos Patsatzis

Houston Refining LP

Overview In August of 2002 LCR underwent a solvent

upgrade from conventional DEA (25-28 wt%) to a formulated UcarsolTM LE-713 DEA and UcarsolTM LE-713 supplied by the same

company Solvent upgrade took approximately 4 months to

complete No unit shutdowns No equipment upgrades

Except for reliability improvements that were identified

2Outline Reason for Change DEA Regeneration Overview Unit Limitations Contactor Limitations

Tighter specifications on product stream

Available Options Capital expenditure Solvent upgrade

Solvent Upgrade What Changed Since 2002?

Reason for Change

FCCU and Coker off gas streams had to be rerouted to an alternate processing unit. Existing processing location was scheduled for an

extensive outage This meant increased amine circulation to meet product

specifications

Product specifications were reduced from 160 to 30 ppmw for H2S CO2 specification remained at the same target

If specifications were not met refinery would have to route the streams to the flare system Extensive environmental implications

3DEA System

Typical System Capacity Needs Regenerators

Regenerator Capacity

Available Excess

Capacity431 1250 B/H 431-A 900 B/H

431-B 600 B/H 250 B/H

DEA Regeneration OverviewPlant Amine Regenerators

Built in 1968 - upgrade to 431B regenerator

Original unit 1954 First amine regenerator

DEA System



Available Excess

Capacity431 1250 B/H 431-A 900 B/H

431-B 600 B/H 250 B/H436 1750 B/H 436-A 1000 B/H

436-B 1000 B/H 250 B/H


Built in 1974 - Part of sulfur/refinery expansion

4DEA System



Available Excess

Capacity431 1250 B/H 431-A 900 B/H

431-B 600 B/H 250 B/H436 1750 B/H 436-A 1000 B/H

436-B 1000 B/H 250 B/H441 2500 B/H 441 3000 B/H 500 B/H

5500 B/H 6500 B/H 1000 B/H


Built in 1995 - Part of major sulfur/refinery expansion

DEA Regeneration Overview Contd

Gas Phase Contactors: Liquid Phase Contactors:Unit Process Stream Unit Process Stream

230 GP Fuel Gas ARU C3/C5 Idle631-A&B Recycle H2 LPG LPG

632 Recycle H2 FCCU Liquid PPs633 Recycle H2 736 Liquid PPs634 Recycle H2 737 Liquid PPs635 Recycle H2636 Recycle H2

FCCU Dry Gas736 Dry Gas737 Dry GasMag Recycle H2BTU Recycle H2

There are 17 Amine Absorbers in the Refinery

5DEA Regeneration Overview Contd

Amine Loading Lean amine loading 0.01-0.02 mol H2S/mol solvent Rich amine loading 0.4-0.6 mol H2S/mol solvent

Amine Velocities Lean/Rich velocities between 4-7 ft/sec No PWHT on older amine system piping

1 out of 3 systems

Corrosion Rates Corrosion coupons indicate 8-16 mils/yr on rich amine

system piping

Amine Regenerator Flow Diagram

6431-A&B DEA REGENERATORS

431-A 431-B

436-A&B DEA REGENERATORS

7441 DEA REGENERATOR

Unit Limitations

Amine Regenerators Lean amine cooling In excess of 140oF Rate limitations Already at 125% of design capacity Reboiler duty Steam supply limitation Throw-away limitation For ammonia control Metallurgy limitations No PWHT

Amine Piping Line velocities (specially around control loops)

Single Storage Tank Feeds all Three Systems Rich Amine Flash Drums

With higher rates amine retention times are reduced

8Contactor Limitations Absorbers

Lean amine cooling Rich amine loading Instrumentation limitations CO2 loading Metallurgy limitations No PWHT

Amine Piping (IBL) Line velocities (rich amine return outlet) Hydraulic constraints

Contactor Limitations ContdBrimstone Analysis

Component Molar%

H2 14.394N2 7.44

CH4 36.002CO 1.293CO2 1.669C2H4 17.984C2H6 15.118H2S 0.581C3H8 2.927i-C4 1.049n-C4 0.925i-C5 0.382n-C5 0.174C6+ 0.062Total 100

Untreated 732 Before LE-713

High CO2 in the contactor feed

9Contactor Limitations ContdBrimstone Analysis

CO2 within acceptable range

Component Molar%

H2 14.104N2 7.593

CH4 36.969CO 1.279CO2 0.369C2H4 18.465C2H6 15.471H2S Non DetectedC3H8 2.784i-C4 1.099n-C4 1.076i-C5 0.474n-C5 0.215C6+ 0.102Total 100

Treated 732 Before LE-713

Contactor Limitations Contd

Component Molar%

H2 6.293N2 0.095

CH4 51.506CO 0.534CO2 0.231C2H4 2.277C2H6 20.437H2S 11.072C3H8 7.433i-C4 0.058n-C4 0.041i-C5 0.006n-C5 0.019C6+ Non DetectedTotal 100.0

Untreated 737 Before LE-713

No CO2 concern on this contactorBrimstone Analysis

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Available Options

Capital Upgrade Upgrade existing

regenerator(s) Invest on new

regenerator

Solvent Upgrade Upgrade single

amine system Upgrade entire

amine system (three amine systems)

Available Options Contd

Capital Upgrade Time constraints ROI below 50% OBL piping

upgrades would be required

Solvent Upgrade Relatively quick

transition ROI at 75% No equipment

upgrades would be necessary

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Solvent Upgrade

Engineering analysis was performed on entire amine system Simulations were constructed with new solvent

properties for amine system including contactors Economics were evaluated

Energy savings Reliability Solvent losses Solvent selection Solvent percent strength

Choice was to upgrade solvent on the entire amine system

Solvent Upgrade Contd

Initial charge was performed using UcarsolTM to get system volume up to desired UcarsolTM LE-713 formulation

Due to the large system volume capacity ~600,000 gallon Solvent strength was to be stepped in three different

phases 30% 35% (target) 40% (if needed)

Solvent loaded directly into the individual systems Monitor closely solvent losses Monitor solvent performance for absorbers in different

service

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Solvent Upgrade Contd Target UcarsolTM LE-713 formulation was

achieved approximately 4 months from the time that system was initially charged Primary driver for the extended time was cost Fresh amine tank was then converted to UcarsolTM LE-

713 tank System leveled at 35 wt% on solvent strength Fresh amine tank was then converted to UcarsolTM

LE-713 tank Brimstone Engineering Services conducted plant

wide performance testing Testing performed before initial charge Testing performed 1 year after system was at steady

state

Solvent Upgrade Contd Systems in place for monitoring

Purchased state of the art GC for in house sampling Training to mitigate system losses

Technical department Operations department

Supplier Involvement

Instrumentation upgrades on key amine absorbers Updated control configuration Temperature control Upgraded analyzers Real time rich loading equations

More intense corrosion monitoring system Going away from corrosion probes and focusing more on TML

readings Ion exchange system for anion and HSAS control

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Current Situation Amine concentration at 40 wt%

Primarily from circulation reduction

Energy savings 27.5 MMBtu/hr Amine losses Down by17%

Primarily due to increased awareness and training Better instrumentation on amine absorbers


Current Situation Amine Loading

Lean amine loading 0.01-0.015 mol H2S/mol solvent

Rich amine loading 0.4-0.45 mol H2S/mol solvent

Amine Velocities Lean/Rich velocities

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Summary

Solvent upgrade was successfully completed Refinery has increased solvent concentration for

energy savings (currently at 40%) COS and trace sulfur species removal was within

target after solvent upgrade No equipment upgrades No unit shutdowns were required

What Changed Since 2002?

FCCU Dry Gas Contactor CO2 specifications changed New contract signed in conjunction with a

compression station New CO2 specification at 500 ppmv

Operation of FCCU has changed over the last two years causing more CO2 slip to the absorber

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Pilot plant data (tests performed at DOWs pilot plant facilities) confirmed that a solvent upgrade was required to meet product specification

Solvent upgrade would be specific to this system only Upgrade is planned for 2nd week of October

Equipment that would allow system optimization had to be installed


Equipment that would allow system optimization had to be installed Installation complete

Training on new system Technical department Operations department

Product exports to 3rd party facility to begin in November

Supplier Involvement

Documents

Blended Amines