How VCI’s Can Reduce Corrosion for UST System Components Presented by David Durling, Zerust Oil & Gas Efim Lyublinski, Monique Posner, Terry Natale, Yefim Vaks, Ronnie Singh, Kelly Baker, Gautam Ramdas Northern Technologies International Corporation, USA

Marcelo Schultz Petrobras, Brazil

Marshall Mott-Smith Mott-Smith Consulting

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AGENDA • What are VCIs • Who NTIC is • Industry Applications – – – – –

Mothballing/Storage AST Floors AST Roofs Pipeline Casings UST Sumps

• Intro to Ethanol Corrosion • Questions 2

Definition - VCI Vapor Corrosion Inhibitors

Also referred to as Volatile Corrosion Inhibitors • A class of corrosion inhibiting compounds which have vapor pressures higher than that of air. • This results in the release of vapor molecules of inhibitor into the air. 3

Definition – Con't VCIs can be engineered to address specific issues causing Corrosion Different Mechanisms for Different Purposes Passivators o Anodic inhibitors that shift the metal potential in the positive direction helping the metal form its own passivation layer

Barriers o Act as a barrier layer between the metal and the environment, adsorption can be either physical (electrostatic) or chemical (sharing electrons)

Scavengers o Eliminate dissolved oxygen from a closed system (neutral or alkaline pH) (sulfite) o Inhibitor reacts with acidic gases in air space (ReCast-R1)

Neutralizer o Reduces the concentration of H+ ions in solution

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Definition Con’t VCI molecules fill space and deposit on all surfaces. • • • • • • •

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Can work for immersed surfaces Not a ‘coating’ Does not change the metallurgy Not permanent Can be painted/welded Non-toxic Can be designed for the service exposure

Many forms of VCI What’s the difference?

1. Self-fogging Flash Corrosion Inhibitor (FCITM) technology – – – – –

High vapor pressure, low vapor density Fast acting Fills vapor spaces immediately Highest volume of protection per weight of active ingredient Navigates complex systems

2. Long-term Vapor Corrosion Inhibitor (VCI) protection – Slower evolving, long-term vapor corrosion inhibitor

3. Long-term Soluble Corrosion Inhibitor (SCI) protection – Contact corrosion inhibitors activated when water present – Chloride “neutralizer”

Not “NEW” Technology

Clean, environmentally friendly Requires no cleaning prior to assembly

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VCIs have been sold through major retailers for years Several ‘consumer market’ products you can try • Lowes • Cabellas

•Flambeau •Kobalt •…others

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Some consumers are more demanding than others … US Navy SEALS

US Marines in Iraq VCI gun sleeves VCI capsules in the engine housing

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NACE Corrosion Innovation Awards Salt Lake City - 2012

Flange Savers™

ReCAST - Roof

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Managing Corrosion

Corrosion cannot be eliminated, it’s mechanism can only be slowed

Applications!

How are VCIs currently being used in Oil & Gas?

Low Temperature Flanges. • Proprietary dual layer plastic film • Impregnated with a VCI to enclose flanges, bolts and weld joints • Average 2+ year life.

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Long Term Corrosion Protection

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Vapor Capsules Numerous applications

Protection of Electrical & Electronic Control Panels and Safety Switch Boxes 18

Applications!

Tank Floors! Underside

Floor Configurations New/Existing – In Service/Out of Service Tank Soil Side Bottom Protection Matrix Cathodic Protection

VCI/SCI

Liquid VCI

Powder VCI

Suggested VCI / SCI System

Sand Base w/ Liner

Yes

Yes

Yes

Yes

- Ring-Wall Injection System - Dry Underside Tube System - Internal Flood System - Dry External Ring System - Wet External Ring System

Sand Base w/o Liner

Yes

Dry System Only

No

Yes

- Dry Underside Tube System - Dry External Ring System

Concrete/Asphalt

No

Yes

Yes

Yes

- Dry External Ring System - Wet External Ring

Double Bottom w/Liner

Effectiveness determined by sand depth

Yes

Yes

Yes

- Ring-Wall Injection System - Dry Underside Tube System - Internal Flood System

Double-Bottom w/o Liner

Effectiveness If original floor has If original floor has determined by sand no penetrations (?) no penetrations (?) depth

Yes

- Dry Underside Tube System - Ring-Wall Injection System? - Internal Flood System?

No

- Chloride Remediation System

Chloride Contaminated Sand Base w/ Liner

Yes

Yes

Yes

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State of Florida “ReCAST-SSB System provides environmental protection substantially equivalent to that provided by compliance with the requirements established in Rules 62-762.501(1)(f)4., 62762.701(1)(b), F.A.C and may be used as a Cathodic protection system… Pursuant to Rule 62762-851(2), F.A.C. … is approved in the State of Florida as a corrosion inhibitor system that is applied to the soil filled area between the secondary containment system of an aboveground storage tank.”

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VCI Effect Under Tank Floors Tank Shell Gap

Tank Floor & Void

VCI Adsorb

Sand Base

VCI Molecules

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External Ring System

CHIME / TUBE SEAL

INHIBITOR TUBE REFILL PORTS

PERFORATED INHIBITOR TUBE

CONCRETE or ASPHALT PAD

Zerust™ Confidential 2014

SSB New Floor Powder System TANK FLOOR

INHIBITOR STRIPS INHIBITOR POWDER

SAND BASE RING WALL MONITORING PORT BERM AREA

Parallel Tubes

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Applications!

Tank Roofs!

Cone roof supports! Continuity of coatings?

Tank roof and support beam H2 O H2SO4

O2 SO2

H2S

Coatings do not effectively cover all surfaces

Examples of AST Roof corrosion Internal acid gas vapors cause underside corrosion

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Mitigate roof underside corrosion The delivery system!

Test dispenser design. New dispenser design.

Inhibitor levels can be monitored and replenished while the tank is “In-Service”.

Molecular vapor pressure disperses the inhibitor from cannisters installed during a tank shutdown. 29

Mono-Molecular Barrier VCI takes preference on steel surface

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Applications!

Pipe Casings!

Pipe Casings Long Term Corrosion Protection Vent Pipe

Surface structure i.e.: road, rail, etc.

Casing Seal 32

Applications!

UST Sump Pit!

UST System Components

UST Sump

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UST Vapor Space Chemistry

+ Water

= Ethanol Vapors

+

Acetic Acid

Bacteria 35

No Inhibitor

February 20, 2014

December 5, 2013 36

UST Test Sump Current Test Locations in Texas Site 1, September 2014

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UST Test Sump Current Test Locations in Texas Site 1 After 5 weeks no Inhibitor

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UST Test Sump Test site 2, October 2014 (this store is around 3 yrs old!)

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UST Test Sump Test site 2 (this store is around 3 years old)

Coupons After 6 Weeks!

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UST Test Sump Test site 3, Jan 2015

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UST Test Sump 3rd site in Texas Coupon after 6 weeks!

Test Coupon

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UST Lab Test

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UST Lab Test

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UST Trial Components

VCI Volatizes in Enclosure

Packet of VCI

Sample Sump

Florida (e10)

Coupon

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UST Control Sump

Coupon Only

December 5, 2013

January 16, 2014

Some Visible Surface Corrosion 47

UST Control Sump

Coupon Only

December 5, 2013

January 16, 2014

Significant Surface Corrosion 48

Beta Test • Relatively Clean Surface & Tightened Fittings Annual Application

Monthly Application

UST Test Sump

Site 1 After 6 weeks with Inhibitor

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UST Test Sump

Site 2 After 6 weeks with Inhibitor

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UST Test Sump

Site 3 After 6 weeks with Inhibitor

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UST Sump - Conclusions 1. Acetic Acid can form in the sumps, due to Ethanol vapors, bacteria and moisture. 2. Absence of any of the three seems to result in a much lower corrosion rate. 3. Vapor Corrosion Inhibitors can reduce corrosion rates.

4. Sump condition is a factor in the effectiveness of the VCI. 5. Testing is expanding into long term trials. 57

Thank you! Questions? David Durling [email protected] 832-482-8781 58