07/06/2016 till the last drop - baretti 1 · entrainment to the wash zone ... -fcc catalyst...

07/06/2016 Till the last drop - Baretti 1


Till the last drop Deep Cut Vacuum Design and Experience Cesare Somaini

Baretti® Your worldwide partner


6th TRC-JCCP/Idemitsu International Symposium Bottom of Barrel Upgrading

Baretti

Bottom of Barrel Upgrading

Deep-cut Vacuum

Process Design

Mechanical Design

Critical Zones Analysis

Conclusions

Contents



• Baretti is an Italian private company created on 1890. It still belongs to the founding family.

• Baretti has been providing Mass Transfer Technologies and Components since 1950.

• Baretti designs and manufactures all kind of columns internals and provide relevant spare parts, technological upgrades and site services.



6th TRC-JCCP/Idemitsu International Symposium Bottom of Barrel Upgrading Bottom of Barrel Upgrading

• Heavier crudes resulting in more residue per bbl of feed

• Increasing demand of middle distillates and declining demand of residual fuels

• Tightening of product specification to meet environmental regulations

• Atmospheric Residue and VGO conversion balances these divergent trends.

• Several separation, thermal and catalytic processing schemes are available.

• The revamp of existing vacuum columns to cut deeper the long residue is an attractive option.



• Deep-cut vacuum target is the maximum HVGO TBP cut point with specified qualities.

Deep-cut Vacuum

• HVGO specifications depends of downstream units.

• Catalytic units are the most sensitive to HVGO quality. (Ni + V, CCR, Asphaltenes, etc.).

• Deep-cut vacuum technology is on market since almost 30 years.

• The severe operating conditions are still challenging the process and the internals design.

• Baretti introduced new features improving operability and reliability of the internals for this technology


6th TRC-JCCP/Idemitsu International Symposium Bottom of Barrel Upgrading Vacuum Internals - Structured Packing

• Structured packing is the most used internal in vacuum towers because of its very low pressure drop.

• The lower is the pressure drop, the deeper is the crude cut point increasing distillate yield.

• Vacuum are characterized by high vapor and low liquid loads : perfect conditions for structured packing.

The low liquid load forms a uniform film on the structured packing surface.

The high vapor load ripples the liquid film increasing surface area and mass transfer.


6th TRC-JCCP/Idemitsu International Symposium Bottom of Barrel Upgrading Vacuum Internals - Structured Packing

Structured packing is available in several materials, thickness, surface treatment, specific surface area and angle of inclination to match a wide spectrum of applications and services

Incr

easi

ng C

apac

ity

Increasing Efficiency


6th TRC-JCCP/Idemitsu International Symposium Bottom of Barrel Upgrading Deep-cut Vacuum

A reduction of 1 mmHg of flash zone pressure gives an increase of 0.3% in the distillates yield.

An inaccurate design has important economic consequence. Reliability and mechanical integrity strongly contribute to profitability


6th TRC-JCCP/Idemitsu International Symposium Bottom of Barrel Upgrading Process Design

Actual performance assessment and characterization of feed are essential to:

• Build a reliable tower model

• Review critical zones: • Transfer Line • Flash Zone • Wash Zone • PA Zones • Stripping zone

• Estimate HVGO quality


6th TRC-JCCP/Idemitsu International Symposium Bottom of Barrel Upgrading Mechanical Design

1950 Main Italian

Refinery

2016 Main ME

Refinery

CDU Column ID 4.000

mm CDU

Column ID 10.000

mm

80.000 bbl/d

400.000 bbl/d

1950

Mech Specs

+7 times area

2016

Mech. Specs


6th TRC-JCCP/Idemitsu International Symposium Bottom of Barrel Upgrading Mechanical Design

ID 8 meters and 16 meters

Two phase feed inlet, Nozzle Ø = 3.6 m.

Diameter 16 m.


6th TRC-JCCP/Idemitsu International Symposium Bottom of Barrel Upgrading Wash Zone

• Mechanical design of internals minimizing liquid stagnation zones is recommended.

• Once it starts, it will quickly grow and invade all the bed.

• Wash Zone failure is due to coking and/or mechanical damages.

• Wash zone coking can be extremely severe limiting the cycle length.



Column ID 10.000 mm Area 78 m2

Support Ring 120

mm

Area 3,8 m2

5 % area is not properly

washed

Wash Zone

Column Ring ID Width

mm mm 800 - 1.300 40

1.301 - 2.400 50 2.401 - 3.600 70 3.601 - 6.100 80 6.101 - 7.600 90

> 7.600 100-120


6th TRC-JCCP/Idemitsu International Symposium Bottom of Barrel Upgrading Wash Zone - Baretti® Anti Clogging Solutions

Baretti® AC Support Ring

• No obstructions to liquid and vapor flow • Very low hold-up • Maximum section opening • Very robust in case of upsets • Cycle length extended to 5 years


6th TRC-JCCP/Idemitsu International Symposium Bottom of Barrel Upgrading Wash Zone - Baretti® Anti Clogging Solutions

Baretti® AC Beams in combination with AC Support Ring or stand alone, assures: • Minimum flow resistance • Minimum hold-up • Optimum vapor distribution



Baretti® ACVG Baretti ACVG valves has been developed specifically for extra fouling resistance.

Specific design to:

Stripping Zone

• Improve liquid flow on tray (Jet effect) • Maximize opening size to reduce the possibility of

clogging • Easy to replace in case of clogging


6th TRC-JCCP/Idemitsu International Symposium Bottom of Barrel Upgrading Transfer Line & Flash Zone

• HVGO quality depends on vapor distribution and entrainment to the wash zone

• The transfer line, the flashing feed inlet device and the above chimney tray must be designed as an integrated system to assure an optimal vapor distribution and minimum entrainment to the wash zone.


6th TRC-JCCP/Idemitsu International Symposium Bottom of Barrel Upgrading Pump-around Empty Zone

• The use of empty sections in heat transfer zones allows a further reduction of the pressure drop.

• A lower flash zone pressure increases production of gasoil.


6th TRC-JCCP/Idemitsu International Symposium Bottom of Barrel Upgrading Conclusion

• Revamps of Vacuum to Deep-cut are a quick execution and short pay-back alternative for Bottom of Barrel upgrade.

• A reliable Deep-cut Vacuum design requires process and mechanical knowledge of columns’ internals combined with advanced simulation systems.

• Baretti Anti Clogging features increase reliability preventing wash zone coking, resulting in extended operating cycle and reduced unplanned shutdown.

• Baretti is an experienced partner with the technical knowledge and the organization to execute Vacuum Deep-cut revamps



Questions? Thank you for your attention



Back-up slides


6th TRC-JCCP/Idemitsu International Symposium Bottom of Barrel Upgrading HVGO Quality - FCC Catalyst poisoning

• More Gas can limit WGC capacity • More Coke can limit coke burning capacity

o Higher regenerator. Temperature o Lower cat/oil ratio o Loss in conversion

• CCR coke maker • Nickel coke and gas makers • Vanadium destroys the zeolites reducing catalyst activity

Higher catalyst consumption to maintain activity Equipment constraints


6th TRC-JCCP/Idemitsu International Symposium Bottom of Barrel Upgrading HVGO Quality - HC Catalyst deactivation

• HC catalyst deactivation is inevitable but the rate at which it occurs varies greatly depending of feed characteristics.

• Coke deposit on catalyst is the main cause of deactivation.

• Resins, asphaltenes & other poly-aromatics in the feed are coke precursor (CCR and C7 Insoluble).

• Control of PNA in feed & HPNA management are required to lengthen the operating cycle and maintain conversion.

• Catalyst deactivation is compensated with RX temperature increase. Lower deactivation rate, lower operational costs.

07/06/2016 till the last drop - baretti 1 · entrainment to the wash zone ... -fcc catalyst...

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