Chemical Hazards Engineering Fundamentals Webinar CCPS An ...

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An AIChE Technology Alliance Chemical Hazard Engineering Fundamentals – Case Studies

June 28, 2021 Slide - 1

Chemical Hazards Engineering Fundamentals Webinar

Case Study – LG Polymers

RUNAWAY STYRENE POLYMERIZATION

Visakhapatnam, Andhra Pradesh, India

May 7, 2020

Reference: Report of the Joint Monitoring Committee

in the Matter of O.A. 73 of 2020 (May 28, 2020)



June 28, 2021 Slide - 2

Chemical Hazards Engineering Fundamentals (CHEF)For the Current Presentation, Please Join Us at:



June 28, 2021 Slide - 3

We begin the study by Identifying the Equipment or Activity for which we intend to perform

an analysis. We will often use the operation of a specific equipment item containing a

specific chemical or chemical mixture to define the activity. For example, the operation of a

storage tank, a reactor, a piping network, etc. Inputs are chemical data, equipment designinformation, operating conditions, and plant layout.

What are the Hazards?

What can go Wrong?

How Bad could it Be?

How Oftenmight it

Happen?

Is the Risk Tolerable?

Identify Chemical

and ProcessHazards

Estimate Frequency

AnalyzeConsequences

Analyze Risk

ImplementAdditional

Safeguards as Needed

Develop Scenarios

Select Equipmentor Activity to be

Analyzed

Sustain Performancefor Life Cycle

of Facility

Case Study – LG PolymersHazard Identification and Risk Analysis (HIRA) Study



June 28, 2021 Slide - 4


The Presenters

• More than 46 years industry

experience with Dow

Chemical - Engineering,

Process R&D, AgroSciences

Technology Center, and

Process Safety

• Part-time Lecturer at

University of Michigan

• Part-time Staff Consultant

for CCPS

• Primary developer of CHEF

and RAST spreadsheet tools

Rahul Raman Ken First

▪ Principal Engineer at Kaypear

▪ 13 years experience in Process

Safety Management with a

specialization in Emergency

Relief Systems.

▪ Active member AIChE DiERS

User Group and the API Sub-

Committee for Pressure-

Relieving Systems.

▪ Contributor to the High Power

Committee Report on the

Styrene Vapor Release

Incident at LG Polymers, India.



June 28, 2021 Slide - 5


Process Description

LG Polymers was established in 1961 as “Hindustan Polymers” for manufacture of polystyrene

and it co-polymers at Visakhapatnam, India. The facility was taken over by LG Chemical

(South Korea) in 1997. The site employees 475 workers and 200 contractors. It is located on

219-acre site with a 30-acre greenbelt to the east. A residential area is located only 150 m

from site to the northwest.

Styrene is primarily stored in two tanks, m5 with a capacity of 3285 metric ton and m6 with a

capacity of 2790 metric ton. Tank m6 is 18 m diameter by 12 m height and contained 1830

metric ton styrene at the time of the incident. This tank is insulated and “flat-roof” with likely a

maximum allowable working pressure less than 0.1 bar (similar to API 650 design). m6 is

equipped with a 2-inch vent and 8-inch vent with dip hatch.

This is an illustrative example and does not reflect a thorough or complete study.



June 28, 2021 Slide - 6


Process Description

Source: The High

Power Committee

Report on the Styrene

Vapor Release

Incident at LG

Polymers India Pvt Ltd

Shri Neerabh Kumar

Prasad, Chief

Secretary,

Government of

Andhra Pradesh



June 28, 2021 Slide - 7


Process DescriptionStyrene monomer is stored at 20 C. However, the refrigeration unit servicing the styrene

storage tanks is often shut off at the end of the day shift (which is often the hottest part of

the day). Temperature is only measured at the bottom of the tank.

T-Butyl Catechol (TBC) is added to the monomer to inhibit polymerization. This inhibitor

requires dissolved oxygen to be effective. Dissolved oxygen is not monitored. TBC

concentration was monitored but no inhibitor was added to the storage tank after April 1 as

there was no stock available on site (although measured inhibitor level was within the

acceptable concentration range). No inhibitor was added for the past 10 years.

The facility was idled on March 25 due to the corona virus pandemic. Preparations were begun

on May 4 for a planned resumption of operations on May 7, 2020; the day of the incident.




June 28, 2021 Slide - 8This is an illustrative example and does not reflect a thorough or complete study.

Case Study – LG PolymersHazard Identification and Risk Analysis versus Incident Investigation

Incident Investigation and Hazard Identification and Risk Analysis (HIRA) often utilize similar concepts

and methodology during the evaluation. In a HIRA study, process upsets and equipment failures

are anticipated which could lead to an unintended Loss of Containment of hazardous material

or energy. The possible Outcome with associated “worst” Consequence is estimated or modeled in

addition to estimation of the likelihood of the Event Sequence and effectiveness of Safeguards or

Protective Layers.

For an Incident Investigation, typically the Outcome and Consequence are known. The Loss

Event is often modeled to better understand how the Outcome and Consequence occurred. Incident

details are often used to “piece together” the Event Sequence to determine the possible Initiating Event

or Cause. Since the Incident has occurred, the Safeguards or Protective Layers were not effective and

conditions contributing to the consequence severity likely existed. This information is often used to

determine which key Management Systems had failed.



June 28, 2021 Slide - 9


The scope of this presentation is focused on the 3000 m3 styrene storage tank (m6). As

this evaluation is related to an incident investigation, little emphasis will be placed on

Frequency Evaluation (the incident has already occurred) or Risk Analysis (evaluation of

protection layers). However, a “worst case” consequence such as might be evaluated during risk analysis will be addressed.



June 28, 2021 Slide - 10


Hazard IdentificationStyrene

Flash Point: 88 ° F (NTP, 1992)

Lower Explosive Limit (LEL): 1.1 % (NTP, 1992)

Upper Explosive Limit (UEL): 6.1 % (NTP, 1992)

Autoignition Temperature: 914 ° F (USCG, 1999)

Melting Point: -24 to -23 ° F (NTP, 1992)

Vapor Pressure: 4.3 mm Hg at 59 ° F (15 ° C);

9.5 mm Hg at 86° F; 10 mm Hg at 95° F (NTP, 1992)

Specific Gravity: 0.906 at 68 ° F (USCG, 1999)

Boiling Point: 293 to 295 ° F (145.5 ° C) at 760 mm Hg (NTP, 1992)

Molecular Weight: 104.16 (NTP, 1992)

IDLH: 700 ppm (NIOSH, 2016)

Reference: Cameo Chemicals



June 28, 2021 Slide - 11


Hazard Identification

Reference: Cameo Chemicals

• Although not considered highly toxic by inhalation, styrene causes moderate irritation

of eyes and skin. High vapor concentrations cause dizziness, drunkeness, and

anesthesia. (USCG, 1999)

• Styrene has been involved in several industrial explosions caused by violent,

exothermic polymerization [Bond, J., Loss Prev. Bull., 1985, (065), p. 25]. The

presence of an inhibitor lessens but does not eliminate the possibility of unwanted

polymerization. Violent polymerization leading to explosion may be initiated by

peroxides (e.g., di-tert-butyl peroxide, dibenzoyl peroxide), butyllithium,

azoisobutyronitrile. Styrene reacts violently with strong acids (sulfuric acid, oleum,

chlorosulfonic acid), and strong oxidizing agents [Lewis, 3rd ed., 1993, p. 1185].

• The heat of polymerization is noted as -154 cal/g by US National Oceanic and

Atmospheric Administration (NOAA)



June 28, 2021 Slide - 12




June 28, 2021 Slide - 13

Case Study – LG PolymersPartial List of Hazard Scenarios per CHEF Example Scenarios

Partial Listing of suggested scenarios for consideration from CHEF Calculation Aid which includes

the likely scenario resulting in the runaway polymerization incident (Uncontrolled Reaction).

Go to Top Example Listing of scenario groups for Common Chemical Process Equipment

Scenario or Hazard

CategoryParameter/ Deviation Applicable Equipment

Initiating Events

(Partial List)Loss Event* Incident Outcome

Excessive Heat Input -

Pool Fire Exposure

Temperature-High

Pressure-High

Heat Input-High

AllScenarios involving spill plus ignition in nearby

liquid-containing equipment

Relief Venting

Equipment Rupture

Equipment Damage

Flammable Release

Toxic Release

Flash Fire or Fireball

Physical Explosion

Business Loss

Ignitable Headspace

Composition-Wrong

Concentration

Electrostatic Charge-High

Electrical Conductivity-Low

All but Liquid-Full Equipment

Flow Control Failure

Failure of Bonding or Grounding

Particle Size Control Failure (Solids)

Wrong Type or Damaged Bag, Pak or Drum (Solids)

Improper Changing Dust Collector Bag or Screen (Solids)

Gasket Leak

Equipment Rupture

Equipment Damage

Flammable Release

Toxic Release


Physical Explosion

Business Loss

Overfill, Overflow, or

Backflow

Level-High

Flow-BackflowAll Liquid Containing Equipment

Level Control Failure

Procedure Failure (Human Error)

Overflow Release

Equipment Damage

Equipment Rupture

Flammable Release

Toxic Release

Physical Explosion

Business Loss

Uncontrolled Reaction

Reaction-High Rate

Temperature-High

Composition-Wrong

AllFlow Control Failure

Temperature Control Failure

Relief Venting

Equipment Rupture

Flammable Release

Toxic Release


Physical Explosion

Business Loss

Uncontrolled Reaction -

Incompatible MaterialsReaction-Wrong Reaction All

Addition of Wrong Recipe (Human Error)

Addition of Wrong Material (Human Error)Equipment Rupture

Flammable Release

Toxic Release


Physical Explosion

Business Loss

Vacuum Damage Pressure-Low AllPressure Control Failure

Mechanical Failure

Full-Bore Leak

Equipment Damage

Flammable Release

Toxic Release

Business Loss



June 28, 2021 Slide - 14

Case Study – LG PolymersRunaway Exothermic Reaction Scenario

To better understand this scenario, we need to address “how”

runaway reaction of an inhibited monomer can occur. This

requires more information on the polymerization inhibitor and

reaction kinetics.



June 28, 2021 Slide - 15

Case Study – LG PolymersRunaway Exothermic Reaction

A potential cause for unintended reaction, particularly during transportation or storage is loss

of inhibitor effectiveness. Styrene is typically inhibited with 4-tert-butylcatechol (TBC) which

requires dissolved oxygen to be effective. This inhibitor also degrades with time and becomes

ineffective. As the plant was shut down, no “fresh” inhibited styrene was added to the storage tank for more than 6 weeks.

Reference: Americas Styrenics LLC, “Safe Handling and Storage of Styrene Monomer” (2016)



June 28, 2021 Slide - 16

Case Study – LG PolymersRunaway Exothermic Reaction – Simple Screening Techniques

Also during the Reactivity Hazards module, use of Reactive Chemicals test data such as

calorimetry was discussed in estimation of reaction kinetics . The initial rate, r0, and

Activation Energy, DE, may be determined as a function of conversion for a simple “n” order

model at any assumed reaction order by linear regression of:

ln (observed rate / (1-c)n) = ln (r0) + (DE/R) (1/TDet – 1/T)

where: x is reaction conversion estimated from an increment of temperature riseR = gas law constant

Various reaction orders may be assumed to determine which provides a “best” fit. Similar

regression analysis may be used for other simple kinetic models.

Often a simple zero or first order kinetic model provides sufficient accuracy for

screening evaluation of reactivity hazards.



June 28, 2021 Slide - 17

Case Study – LG PolymersRunaway Exothermic Reaction – Simple Kinetics

This reactive chemicals experiment was run with

a Thermal Inertia (or f factor) of 1.56. In other

words, 36% of the observed heat was lost to the

experimental apparatus. To scale this data to a

large storage tank (for which little of the reaction

heat would be lost to heating the tank itself), we

need to correct the information by multiplying the

initial observed heat rate by 1.56 and recognizing

that, in a near adiabatic system, the overall

temperature rise would be 1.56 higher than this

observation. Also note that over a broad region

of the reaction, the reactor order may not

significantly impact the overall rate estimate.

RC Data Reaction ModelingUninhibited Styrene at F = 1.56

0.01

0.1

1

10

100

0 50 100 150 200 250 300

Temperature, C

Tem

pera

ture

Ris

e R

ate

C/m

in

Rate at n=2

Rate at n=0

Heat Rate Data

Rate at n=1

r0 D E r 2 F ss

reg

Fit at n=2 0.0305 22.1 0.948 618.289 7.73E+02

Fit at n=1 0.0346 19.2 0.638 59.935 1.44E+03

Fit at n=0 0.0395 16.2 0.197 8.336 2.92E+03

RC Data Reaction ModelingUninhibited Styrene at F = 1.56

0.01

0.1

1

10

100

0 50 100 150 200 250 300

Temperature, C

Tem

pera

ture

Ris

e R

ate

C/m

in

Rate at n=2

Rate at n=0

Heat Rate Data

Rate at n=1

Rate at n=2

Rate at n=0

Heat Rate Data

Rate at n=1

r0 D E r 2 F ss

reg

Fit at n=2 0.0305 22.1 0.948 618.289 7.73E+02

Fit at n=1 0.0346 19.2 0.638 59.935 1.44E+03

Fit at n=0 0.0395 16.2 0.197 8.336 2.92E+03

R at 80 C0 D E r 2 F ssreg

Fit at n=2 0.0305 22.1 0.948 618.289 7.73E+02

Fit at n=1 0.0346 19.2 0.638 59.935 1.44E+03

Fit at n=0 0.0395 16.2 0.197 8.336 2.92E+03



June 28, 2021 Slide - 18

Case Study – LG PolymersRunaway Exothermic Reaction – Simple Screening Techniques

During the Reactivity Hazards module, the concept of Temperature of No Return

was discussed. As the storage tank was likely insulated due to also be refrigerated,

heat loss would be very small.

Beyond the Temperature of No Return, if no action is taken, the reaction will

proceed to a maximum rate.

Note that most reactions follow an Arrhenius or exponential relationship with temperature while heat losses are

generally linear with temperature.

Heat Gain from

Exothermic Reaction

Proportional to e-DE / R T

Hea

t R

ate

Temperature

Heat Loss to

Surroundings

= U A DT

Temperature of No Return, TNR



REACTIVITY HAZARDS INPUT INFORMATIONRequired Inputs are Shaded "Yellow"

Description:

Select Reactivity Screening Estimate

Input Value Input Units Equation Input Equation Units

Initial (or Detected Onset) Temperature, T0 80 C 80 C

Initial Pressure, P0 0.001 bar 0.00 bar gauge

Initial Observed Temperature Rate, r0 0.035 C/min 0.035 C/min

Activation Energy, DE 19.2 kcal/g mole 80.33 kJ/g mole

Heat of Reaction per Mass, DHr -154 cal/g 644.34 kJ/kg

Contents Average Heat Capacity, C 1.93 kJ/kg 1.930 kJ/kg C

Total Reaction Mass 1830000 kg 1830000.00 kg

Net Mole Vapor Generated/Liter Contents g mole/liter contents

Exothermic or Endothermic Reaction Exothermic Assumed Exothermic if blank

Vapor or Liquid Phase Reaction Liquid Assumed Liquid if blank

Thermal Inertia of Testing Device 1.56 Note: A value of 1 indicates an adiabatic data. Assumed 1 if blank.

Equipment of Vessel Fill Fraction, FF 0.66 Assumed 0.5 if blank

Vol Ratio (Vr / VV) = 1 for vapor phase or Fill Fr / (1 - Fill Fr) for liquid phase reaction = 1.941

Temperature Temp Units Vapor Press Pressure Units

Input Temperature 1 and Vap Press 1 15 C 4.3 mmHg

Input Temperature 2 and Vap Press 2 145.5 C 760 mmHg

Vapor Pressure at Temperature 1 15 C 0.57 kPa absolute

Vapor Pressure at Temperature 2 145.5 C 101.33 kPa absolute

Estimated Vap Pressure at Initial Reaction Temperature, PVP@To = 0.12 bar

Estimated Vap Pressure at Max Reaction Temperature, PVP@Tmax = 87.83 bar

Estimated Pad Gas Pressure at T0 = P0 - PVP@To = 0.89 bar


Equipment or Vessel Heat Transfer Area, A 950 sq m 950.000 m2

Heat Loss Coefficient, U 0.0005 kwatt /sq m C 0.0005 kWatt/m2 C

Coolant Temperature, TCoolant 20 C 20 C

Ref Temperature for Time to Max Rate, TRef 30 C 30 C

Estimated Temp Rate at TREF, qREF = 0.0006 C/min

Temperature of No Return

Evalutaion of runaway polymerization in Styrene Storage Tank based on Accelerating Rate Calometry Data for

uninhibited Styrene

Clear Inputs

June 28, 2021 Slide - 19

Case Study – LG PolymersRunaway Exothermic Reaction – Temperature of No Return


Enter information from the

Reactive Chemicals “test”

including Initial Temperature,

Initial Temperature Rate,

Activation Energy, Heat of

Reaction, and Thermal Inertia

Enter Equipment Information

such as Total Reaction

Mass, Fill Fraction, Heat

Transfer Area, Heat Loss

Coefficient, and Coolant

Temperature

Enter Reference Temperature

for “Time to Maximum Rate”

estimation if desired.

Enter Chemical Data such

as Liquid Heat Capacity

and Vapor Pressure of the

reaction system

ln(Vap Press) = A -B / (T + 273)

Initial Temperature for Plot = C Vap Press A 16.0384

Maximum Temperature Rise for Plot = 333.9 C Vap Press B 4779.285

Vap Press at Initial Temperature = 0.12 bar Pad Gas = 0.89 bar

Conversion Temp, C Vap Press, barTotal Press, bar Temp Rate Cool Rate, C/min

0.00 0.69 1.7942E-05 #N/A

0.001 40 0.02 0.81 0.0017 0.0002

0.005 80 0.12 1.01 0.0543 0.0005

0.1 113.4 0.39 1.37 0.5230 0.0008

0.2 146.8 1.05 2.11 3.3967 0.0010

0.3 180.2 2.43 3.57 16.1995 0.0013

0.4 213.5 5.00 6.23 59.9691 0.0016

0.5 246.9 9.40 10.72 178.8640 0.0018

0.6 280.3 16.37 17.77 439.0995 0.0021

0.7 313.7 26.77 28.25 889.5195 0.0024

0.8 347.1 41.50 43.07 1439.2231 0.0026

0.9 380.5 61.53 63.18 1595.2057 0.0029

0.95 397.2 73.82 75.52 1152.7337 0.0030

0.98 407.2 82.00 83.71 570.1461 0.0031

0.99 410.5 84.86 86.59 305.5541 0.0032

0.995 412.2 86.32 88.05 158.1299 0.0032

Maximum Adiabatic Temperature (equation 4-1), TMax = T0 - DHr / C

TMax = 80 + 644.3 / 1.93 = 413.9 C

Maximum Adiabatic Pressure (equation 4-2), Pmax = Ppad (Tmax / T0 ) + PVP@Tmax + b R Tmax ( Vr / VV)

Pmax = 0.89 ( 413.9+273 ) / (80+273 ) + 87.83 + 0 ( 0.083 ) (413.9+273) ( 1.94 ) = 89.57 bar

Temperature of No Return (equation 4-4), TNR = 1 / [R ln (r0 / rTNR) / DE + 1 / T0]

where rTNR = U A (TNR - Tcoolant) / ( M C )

TNR solved by trial and error or graphically yields: < Coolant T C

Time to Maximum Rate (equation 4-5), tMR = R TRef2 / ( rRef DE )

where rRef determined by thermal kinetic expression: r = r0 exp[ -( DE / R ) ( 1 / TRef - 1 / T0 )

tMR = 8.3145 ( 30 + 273 )^2 / ( 0.001 ( 80332.8 ) ) = 15928.0 min

or 11.1 day

MAXIMUM ADIABATIC TEMPERATURE and PRESSURE

Reactivity Hazards - section 4.7

TIME TO MAXIMUM RATE - Exothermic Reaction


TEMPERATURE OF NO RETURN - Exothermic Reaction


0.0001

0.001

0.01

0.1

1

10

100

1000

10000

0 50 100 150 200 250 300 350 400 450

Tem

pera

ture

Rat

e (C

/min

) or

Pres

sure

(bar

)

Temperature, C

Temperature Rate or Pressure versus TemperatureAssuming 1st Order Reaction

Vap Press, bar Total Press, bar Temp Rate Cool Rate, C/min

The Temperature of

No Return less than

ambient operating

temperature.



June 28, 2021 Slide - 20


Simple Screening Technique - Time to Maximum Rate

A simple technique to better understand the time frame of a runaway exothermic

reaction is evaluation of the Time to Maximum Rate. This correlation (based on

a zero-order reaction) may be used to estimate the approximate time required for

runaway reaction under adiabatic conditions.

TMR = R Ti2 / (qi DE) where Ti is the initial temperature, qi the initial reaction heat rate,

R the gas law constant, and DE is the Activation Energy.

TMR from 20 C (293 K) is 30.7 days



Times exclude the induction period for depletion of the inhibitor


This indicates that upon depletion of the inhibitor with loss of

cooling, a runaway reaction where venting or equipment failure

may occur might happen in approximately 30 days if no action

is taken starting from the normal operating temperature.



June 28, 2021 Slide - 21

Polling QuestionDo You Have Access to Reactive Chemicals Testing

and Interpretation at Your Company?

❑ Have Internal Testing Capability and Internal Interpretation Expertise

❑ Use Contract Laboratories for Testing and Interpretation

❑ Use Contract Laboratories for Testing with Internal Interpretation

❑ Do Little or No Reactive Chemicals

Testing or Data Interpretation

❑ Do Not Know



June 28, 2021 Slide - 22




June 28, 2021 Slide - 23

Case Study – LG PolymersPotential Incident Outcome

Generalized OutcomeEvent Tree

Property Damage or Business Loss

Vapor, Liquid Mist,or Suspended Dust

Liquid

Flash Fraction, Aerosol and Pool

Evaporation

NotIgnited

Ignited

NotIgnited

Early Ignition

Vapor Cloud Explosion

Dermal Toxic, Hot, or Corrosive

Aquatic or Ingestion Toxic

Outdoors

NotIgnited

Outdoor Flash or Jet Fire

Outdoor Toxic Vapor Cloud

Indoor Toxic Release

Building Explosion

Indoors

Pool Fire

Chemical Exposure

Environmental Damage

BLEVE or Fireball

Loss of Containment

(Release of Hazardous Material or Material in Hazardous Service)

Equipment Rupture Physical

Explosion

Equipment Damage

Ph

ysic

al S

tate

Lo

cati

on

Excessive Heat with

Vapor Venting

NotIgnited

LateIgnitionNot

Ignited

Early Ignition

Release of Energy(Excessive Pressure,

Reaction, Internal Deflagration, etc.)

Peak Pressure >> MAWP

LateIgnition

Indoor Flash or Jet Fire

Loss Events

Incident Outcome

Ignited

NotIgnited

Gas

ket

Fai

lure

Head Space Deflagration

Outcome for

Outdoor Vapor

Release



June 28, 2021 Slide - 24

Case Study – LG PolymersRunaway Exothermic Reaction – Source Model

At 148 C (styrene boiling point at 0.1 bar gauge), the heat rate for a runaway reaction per the

Temperature Rate versus Temperature graph is roughly 3 C/min (0.05 C/sec), the heat of vaporization

for styrene is 351 kJ / kg, and liquid heat capacity is 2.14 kJ / kg C. The storage tank contained 1830

metric ton or 1830000 kg such that the total reaction heat rate is:

0.05 C /sec (2.14 kJ / kg C) 1830000 kg = 195800 kJ / sec or 195800 kW

The vaporization rate to balance the reaction heat is = 195800 kJ / sec / 351 kJ / kg = 558 kg/sec.

The heat of polymerization is approximately twice the heat of vaporization such that 1 kg reacted

would vaporize 2 kg styrene. The total quantity vented is estimated as approximately 0.61 fraction

remaining once venting starts ( 2 kg vaporized / (2 kg vaporized + 1 kg reacted))

= 0.407 kg vaporized / initial kg (1830000 kg) = 744200 kg total vaporized which compares to total of

800000 kg estimated in the incident report.

This estimate represents a vapor venting scenario if there were sufficient relief device vent

area or a weak-seamed roof. It represents a “worst case” that might be used in risk analysis.



June 28, 2021 Slide - 25

Case Study – LG PolymersDispersion Model for “Worst Case” Venting Scenario

Using the CHEF Calculation Aid, a 558 kg/sec styrene release would reach the following distances

for specific concentrations at a wind speed of 3 m/sec and residential surface roughness.

Concentration

(ppm)

Distance

(m)

LFL of 8800 ppm* 573*

½ LFL of 4400 ppm* 870*

1000 2080

2000 1388

5000 806

*based on flammable averaging time of 18 sec

These estimates represent a “worst

case” consequence as might be

evaluated during risk analysis.

VAPOR DISPERSION INPUT INFORMATION

Required Inputs are Shaded "Yellow"

STEP 1 - Select Location, Type of Release, Concentration and Distance of Interest

Release Location (Assumed Outdoor if Blank)

Type of Release

Use Averaging Time Correction for Flammable Release Yes


Concentration of Interest 0.88 vol % 8800 ppm

Concentration of Interest for Hazard Analysis is typically 1/2 LFL, LFL, ER-2, ER-3 or LC 50

Outdoor Downwind Distance of Interest, X m

Distance of Interest is typically to the property limit, to an unrestricted work area, or to an occupied building

Note that Concentration of Interest must be entered for estimation of Instantaneous (or puff) release

STEP 2 - Enter Chemical Properties (or Select Chemical Name from Pic List)

Cas No.

Chemical Name 100-42-5

Data Table Value

Lower Flammable Limit, LFL 0.88 vol %

ERPG-3 Concentration 1000 ppm


Input Value Equation Input

Vapor Molecular Weight, Mw 104.15 104.15

Normal Boiling Point, TB 144.6 144.6 C

STEP 3 - Enter Process Information

Process Inputs: Input Value Input Units Equation Input Equation Units

Airborne Rate, Q 558 558 kg/sec

Vapor Temperature, T 148 148 C

Total Release Quantity, Q* (Leave Blank if Unlimited) 744200 744200 kg

Liquid or Two-Phase Release Velocity* (Flashing Liquid) m/sec

Initial Fraction Vapor*, f 0 (Flashing Liquid Only) Fraction

kPa absolute

*Note that these inputs may not significantly change results

STEP 4 - Enter Equipment and Plant Layout Information

Equipment and Plant Layout Inputs: Input Value Input Units Equation Input Equation Units

Diameter of Hole or Discharge Piping, d0 m

The hole size for vapor release estimate or diameter of relief system discharge piping. If blank, no jet mixing used.

Release Elevation, h (Blank assumed at Ground) 12 12 m

Release Direction (Assumed Horizontal if Blank)

Enclosed Process Area Volume, VBldg cu m

Enclosed Process Area Ventilation Rate Air Changes/Hr (Assumed 1 if Blank)

Vapor Pressure at Release Temp

(Subcooled Liquid Only)

Outdoor

Styrene

Vapor

Input Units may be changed - Input Values in "blue" will be converted to appropriate equation units

If "Yes" dispersion concentration

is approximately doubled

For reference in determining

concentration of interest

Leave Blank to accept

Chemical Data Table

Mw

Clear InputsClear Inputs

per Correlation Details with Concentration in ppmv

Plume or Continuous: C m = 3.8E+08 1.75 )

Puff or Instantaneous: C m = 6.5E+06 2.29 )

per Correlation Details for 1.5 m/sec F Stability with Concentration in ppmv



Test for Plume versus Puff Model at Dispersion Conditions: (equation 12-20)

If Q > (a*/a) u Q* Xb-b* ---> Instantaneous Model (from equating Puff and Plume correlation at X)

558 kg/sec < 0.01689 (3 m/sec) 744200 kg (614 m)^-0.54 or 1194.93 kg/sec -->

Alternate weather Puff versus Plume Model

558 kg/sec < 0.080222 (1.5 m/sec) 744200 kg (604 m)^-0.71 or 932.52 kg/sec -->

Estimated Exposure Duration - Continuous Dispersion (Equations 12-21, 12-23)

t = Q* / Q for Continuous or 2 (0.2) [Q* T amb / (Mw C)]0.37

/ Wind Speed for Instantaneous

t = 744200 Kg / 558 Kg/sec = 1333.7 sec

Alternate weather Estimated Exposure Duration

t = 744200 Kg / 558 Kg/sec = 1333.7 sec

Maximum Downwind Distance to Concentration of Interest (equations 12-9, 12-13)

Continuous (equation 37): X = a [ Q / ( u Mw Cm ) ]b - X0

r air = 1.18 Kg/m3 = 78200 [ ( 558 ) / { ( 3 ) 104.15 ( 8800 ) } ]^0.57 - 41.3 = 573 m

at ambient conditions Instantaneous (equation 41): X = a* [ (Q* / ( Mw Cm ) ]

b* - X0

= 940 [ 744200 / ( 104.15 ( 8800 )) ]^0.44 - 41.3 = m

( Q* / Mw ) / ( X ^

Continuous

for 3 m/sec Wind Speed, Class D Atmospheric Stability, and Residential Surface Roughness

( Q* / Mw ) / ( X ^

SIMPLE VAPOR DISPERSION

( Q / Mw ) / ( u X ^

Continuous

( Q / Mw ) / ( u X ^

Maximum Concentration at Ground Elevation

Effective Release Elevation

Release Elevation

Ground Elevation

Cloud Centerline

Concentration at Specified Distance

and Elevation

Maximum Concentration at Specified Distance

Outdoor Vapor Release

Initial Dilution

Distance Correction for

Initial Dilution, DXt

Show Correlation Details

Hide Correlation Details



June 28, 2021Slide - 26

Case Study – LG PolymersVapor Cloud Explosion Model for “Worst Case” Venting Scenario

Using the CHEF Calculation Aid, a 558 kg/sec styrene release and distance to LFL concentration of

573 m, a Vapor Cloud Explosion would yield:

Distance to 1 psi blast

overpressure of 604 m

from the release location.

Distance to 2.3 psi blast

overpressure of 430 m from

the release location.

These estimates represent a

“worst case” consequence

as might be evaluated

during risk analysis.

EXPLOSION INPUT INFORMATION


STEP 1 - Select Type of Explosion and Distance of Interest

Type of Explosion:


Distance of Interest, X 430 430 m

STEP 2 - Enter Equipment Burst Pressure and Volume for Physical Explosion Skip Step

Physical Explosion Inputs: Input Value Input Units Equation Input

Burst Pressure (gauge), PB - P0 kPa gauge

Equipment Volume, VEquip cu m

Burst Temperature, TBurst C

Fraction Liquid Level (if Superheated), FF

Flash Fract during Depressurization, FV

STEP 3 - Enter Quantity and Heat of Reaction for Condensed Phase Explosion Skip Step

Condensed Phase Detonable Inputs: Input Value Input Units Equation Input

Mass of Material, M kg

Heat of Reaction per Mass, DHR kJ/kg


Cas No.


Data Table Value User Value Equation Input


Liquid Density, rL (at Burst Temperature) 924 924 kg/m3

Lower Flammable Limit, LFL 0.88 0.88 vol %

Fuel Reactivity based on Fundamental Burning Velocity Medium Medium(Leave User Value Blank to accept Data Table Value)

Ideal Gas Vapor Density, rV (at Burst Temperature) 4.63 kg/m3

STEP 5 - Enter Information for Building or Head Space Explosion Skip Step

Building or Head Space Explosion Inputs: Input Value Input Units Equation Input

Building or Head Space Volume, VB cu m

Degree of Internal Congestion Assumed "Medium" if Blank

1 D Confinement? (such as Fire Tube Boilier) Assumed "No" if Blank

STEP 6 - Enter Information for Vapor Cloud Explosion

Vapor Cloud Explosion Inputs: Input Value Input Units Equation Input

Distance to LFL from Dispersion Model , XLFL 573 m 573 m

Vapor Rate 558 kg/sec 558 kg/sec

Wind Speed (Assumed 3 m/sec if Blank) 3

Degree of Outdoor Congestion Assumed "Medium" if Blank

Vapor Cloud Explosion

Styrene


Clear Inputs

Vapor Cloud Explosion (based on 3 m/sec wind speed)

Low Medium High

High 0.5 >1 >1

Low-Medium 0.35 0.5 1

Flammable Cloud Volume (equation 13-4), VC = 2440 Q XLFL / ( F u Mw CLFL) =

2440 ( 558 ) ( 573 ) / [ 2 ( 3 ) ( 104.15 ) ( 0.88 ) ] = 30000 m3

Distance to Explosion Epicenter, X EE = 0.5 X LFL = 0.5 ( 573 ) = 286.5 m

Potential Explosion Site Volume limited to 30000 cu m

Explosion Energy (equation 13-3), QE = 3500 VPES = Note: P A = 101.3 kPa

3500 ( 30000 ) = 105000000 kJ

Scaled Overpressure at 1 psi = 0.068

Scaled Distance, R = X / (2 QE / P0 )1/3

= 2.5

Distance to 1 psi = R (2 QE / P0 )1/3

+ XEE =

2.5 [ 2 ( 105000000 ) / 101.3 ]^1/3 + 286.5 = 603.7 m

From Graph, Scaled Distance, R = ( X - XEE) / (2 QE / P0 )1/3

=

( 430 - 286.5 ) / [ 2 ( 105000000 ) / 101.3 ]^1/3 = 1.131

Scaled Overpressure = 0.158

Overpressure at 430 m = 2.3 psi or 16 kPa

Fuel

Reactivity

Obstacle Density or Congestion

Use Mach 0.5 for Low-

Medium Fuel Reactivity and

Medium Confinement

BAKER-STREHLOW-TANG MODEL

0.01

0.1

1

10

100

0.1 1 10

Sca

led

Ove

rpre

ssu

re,

PS

= P

0/

P a

Scaled Distance, R = X / (2 QE / Pa)1/3

Baker-Strehlow-Tang Overpressure Curves

Mach > 1

Mach 1.0

Mach 0.7

Mach 0.35

Mach 0.5

1 psi overpressure



June 28, 2021 Slide - 27

Case Study – LG PolymersDevelopment of “Worst Case” Scenario Consequence Severity

ConcentrationsBlast Overpressure

2.1 km to

1000 ppm

0.6 km to 1 psi

overpressure

0.43 km to 2.3 psi

overpressure

0.81 km to 5000 ppm

0.87 km to 4400 ppm ½ LFL

Estimation of Concentration and Blast Overpressure versus Distance per CHEF/RAST

1.4 km to

2000 ppm

0.57 km to

8800 ppm LFL



June 28, 2021 Slide - 28

Case Study – LG PolymersScenario Consequence Severity

o Had the styrene vent rate been close to that estimated from the reaction kinetics assuming a

“homogeneous” system, the hazard zones would have been significantly greater than actual

observation.

o If the tank had ruptured or the roof opened such as a “weak seam roof”, then contents would

likely have continued reacting and vaporizing styrene at near this rate and temperature.

o Since the tank did not fail, the actual vent rate of styrene was likely close to the 8 inch

emergency vent capacity.

Why was the actual event consequence severity so much lower than the

screening estimate?



June 28, 2021 Slide - 29


Additional Questions

• Would a more detailed kinetic model account for the differences?

• How long might it take for the inhibitor to become depleted?

• How effective was the tank cooling system?

• Is it feasible to reach runaway reaction conditions to occur within the time

frame of the plant shutdown?

• Other questions?



June 28, 2021 Slide - 30


Detailed Kinetic Modeling

• Hui and Hamielec model is a well-established kinetic model to represent the

Runaway Reaction of Styrene Monomer. Excellent agreement to experimental

results between 100 °C to 200 °C. Design Institute for Emergency Relief

Systems (DiERS) Recommended Model.

• Inhibitor depletion was included in the model based on work by Harold Fisher.

“H Fisher (1991). A Runaway Styrene Polymerization Incident with Inhibitor

Effectiveness Study. Pittsburgh, PA.”

• A Runaway Polymerization was simulated for the m6 tank using a DiERS

version of SuperChemsTM software from ioMosaic.



Slide - 34

❑ With 30 °C starting temperature, the time

taken to reach relief device set point is 23

days

❑ Rapid opening and closing of relief device

as the temperature increases beyond 80 °C. Relief valve remains open at 100 °C.

❑ Premature vessel failure as relief device

is not adequately sized to handle the

runaway reaction scenario under true

adiabatic conditions occurs at 587

hours or 24.5 days (versus estimated time

to maximum rate of 11.1 days excluding

inhibitor depletion starting at 30 °C)


SuperChems Model Results




Slide - 35


SuperChems Model Results


• The detailed model predicted the runaway reaction could occur within a time

frame consistent with the 5 week plant shutdown. However, an initial temperature of 30 °C versus the operating temperature of 20 °C was needed.

• Simulation of the event indicated the vessel would fail as the relief device was

grossly undersized for the required vent rate.

• Detailed Kinetic Modeling did not identify why the vent rate was much lower

than estimated such that the tank did not fail. There are other factors that need

to be considered.



June 28, 2021 Slide - 36


Inhibitor Depletion ModelSource: DiERS User Group, H Fisher (1991). A Runaway Styrene Polymerization Incident with Inhibitor Effectiveness Study. Pittsburgh, PA.

Source: DiERS User Group Singh.et.al. (Fall 2012). Determination of Self Accelerating Decomposition Temperature (SADT) of Styrene using Accelerating Rate Calorimeter. Concord, MA



June 28, 2021 Slide - 37


Temperature & Inhibitor Stratification

Source: The High Power Committee Report, GoAP

Graph below shows 15 ppm

inhibitor concentration 3 days prior

to incident

400 ppm polymer noticed 2 days before incident



June 28, 2021 Slide - 38


Process Description – Best Practice

Source: YouTube

https://www.youtube.com/watc

h?v=-rVRTM_7JVc

Protego®

A suction float in the refrigeration

inlet line and an educator in the

refrigeration outlet line is

recommended to promote mixing

inside the tank

https://www.youtube.com/watch?v=-rVRTM_7JVc



June 28, 2021 Slide - 39


Process Description – Best Practice

Source: The High Power

Committee Report, GoAP



June 28, 2021 Slide - 40


Temperature & Inhibitor Stratification

Source: The High Power Committee Report, GoAP

Increasing Temperature

Increasing Inhibitor concentration



June 28, 2021 Slide - 41

Case Study – LG PolymersEstimate of Actual Styrene Venting for Use in Incident Investigation

o In addition to thermal gradients within the tank, several actions were taken that

may have slowed the reaction rate including adding water and a high

temperature inhibitor.

o The actual vent rate was approximately 10 kg/sec for the 8-inch vent

significantly reducing the distance to potentially toxic concentration and potential

for Vapor Cloud Explosion. The vent duration was more than 20 hours.

o This incident resulted in 12 fatalities and more than 1000 people effected due to

toxic inhalation impacts.




June 28, 2021 Slide - 42

Case Study – LG PolymersEstimated Maximum Capacity for Tank Vent

SOURCE MODELS INPUT INFORMATION


Hole Size (equation 11-1):

STEP 1 - Select Type of Release V = 23 cd d2 P0 { [ (PA/P0)

1.429- (PA/P0)

1.714] Mw / T }

1/2 based on 1.4 isentropic exponent

PA / P0 = 0.91 Note: P A = 101.3 kPa

" V = 23 ( 1 ) ( 0.21 )^2 ( 111.3 ) { ( 0.91 )^1.429 - ( 0.91 )^1.714 } ( 104.15 ) / ( 421.15 )}^1/2 =

STEP 2 - Enter Required Release Information V = 8.51 kg/sec - or - 1120 lb/min

1 hr Release = 30636 kg - or - 67399.2 lb

Release Inputs: Input Value Input Units Equation Input Equation Units

Hole Size, d 8.25 in 0.20955 m Specified Rate:

Coefficient cd (typically Square Edged Hole) 1 dimensionless V = kg/sec - or - lb/min

Heat Input Rate, q kWatt 1 hr Release = kg - or - lb

Specified Rate (at either specified Hole kg/sec Size or Release Pressure) Heat Input with Vaporization (equations 11-7 to 11-10):

Process Inputs: Input Value Input Units Equation Input Equation Units V = q / DHV = ( 0 ) / ( 351 )

Release Temperature, T 148 148 C V = kg/sec - or - lb/min

Release Pressure (gauge), P0 - PA 0.1 bar 10 kPa gauge 1 hr Release = kg - or - lb

Total Inventory (Leave Blank for 1 hour leak) kg

10 Minute Release:

STEP 3 - Enter Chemical Properties (or Select Chemical Name from Pic List) V = kg/sec - or - lb/min

Cas No. 1 hr Release = kg - or - lb


Equipment Rupture:

(Leave Input Value Blank to accept Chemical Data Table Values) Total Release = kg - or - lb


Hole Size

Rounded Nozzle

ESTIMATED VAPOR RELEASE RATE

Styrene


Equivalent Diameter of 8 inch

vent plus 2 inch breather and

use maximum discharge

coefficient for “rounded”

nozzle of 1.

Since the tank pressure

could have been somewhat

higher than the maximum

allowable working pressure

without failure, round result

up to 10 kg/sec



per Correlation Details with Concentration in ppmv



per Correlation Details for 1.5 m/sec F Stability with Concentration in ppmv



Test for Plume versus Puff Model at Dispersion Conditions: (equation 12-20)

If Q > (a*/a) u Q* Xb-b* ---> Instantaneous Model (from equating Puff and Plume correlation at X)

10 kg/sec < 0.00438 (3 m/sec) 744200 kg (425 m)^-0.51 or 436.93 kg/sec -->

Alternate weather Puff versus Plume Model

10 kg/sec < 0.020024 (1.5 m/sec) 744200 kg (425 m)^-0.69 or 348.09 kg/sec -->

Estimated Exposure Duration - Continuous Dispersion (Equations 12-21, 12-23)

t = Q* / Q for Continuous or 2 (0.2) [Q* T amb / (Mw C)]0.37

/ Wind Speed for Instantaneous

t = 744200 Kg / 10 Kg/sec = 3600.0 sec

Alternate weather Estimated Exposure Duration

t = 744200 Kg / 10 Kg/sec = 3600.0 sec

Maximum Downwind Distance to Concentration of Interest (equations 12-9, 12-13)

Continuous (equation 37): X = a [ Q / ( u Mw Cm ) ]b - X0

r air = 1.18 Kg/m3 = 143400 [ ( 10 ) / { ( 3 ) 104.15 ( 1000 ) } ]^0.56 - 8.7 = 417 m

at ambient conditions Instantaneous (equation 41): X = a* [ (Q* / ( Mw Cm ) ]

b* - X0

= 940 [ 744200 / ( 104.15 ( 1000 )) ]^0.44 - 8.7 = m

Alternate weather Maximum Downwind Distance to Concentration of Interest

Continuous (equation 10-xx): X = a [ Q ( F ) / ( u Mw Cm ) ]b - X0

= 103300 [ ( 10 ) / { ( 3 ) 104.15 ( 1000 ) } ]^0.57 - 8.3 = 416 m

Instantaneous (equation 10-xx): X = a* [ (Q* / ( Mw Cm ) ]b*

- X0

= 810 [ 744200 / ( 104.15 ( 1000 )) ]^0.41 - 8.3 = m

for 3 m/sec Wind Speed, Class D Atmospheric Stability, and Residential Surface Roughness

( Q* / Mw ) / ( X ^

SIMPLE VAPOR DISPERSION

( Q / Mw ) / ( u X ^

Continuous

( Q / Mw ) / ( u X ^

( Q* / Mw ) / ( X ^

Continuous

Maximum Concentration at Ground Elevation

Effective Release Elevation

Release Elevation

Ground Elevation

Cloud Centerline

Concentration at Specified Distance

and Elevation

Maximum Concentration at Specified Distance

Outdoor Vapor Release

Initial Dilution

Distance Correction for

Initial Dilution, DXt

Show Correlation Details

Hide Correlation Details

June 28, 2021 Slide - 43

Case Study – LG PolymersDispersion Model for Estimate of Actual Styrene Venting

Using the CHEF Calculation Aid, a distance of 416 m to 1000 ppm by volume is estimated at a

wind speed of 1.5 m/sec and residential surface roughness. (The actual wind speed is unknown.)VAPOR DISPERSION INPUT INFORMATION


STEP 1 - Select Location, Type of Release, Concentration and Distance of Interest

Release Location (Assumed Outdoor if Blank)

Type of Release

Use Averaging Time Correction for Flammable Release


Concentration of Interest 1000 1000 ppm

Concentration of Interest for Hazard Analysis is typically 1/2 LFL, LFL, ER-2, ER-3 or LC 50

Outdoor Downwind Distance of Interest, X m

Distance of Interest is typically to the property limit, to an unrestricted work area, or to an occupied building

Note that Concentration of Interest must be entered for estimation of Instantaneous (or puff) release


Cas No.


Data Table Value

Lower Flammable Limit, LFL 0.88 vol %



Input Value Equation Input


Normal Boiling Point, TB 144.6 144.6 C

STEP 3 - Enter Process Information

Process Inputs: Input Value Input Units Equation Input Equation Units

Airborne Rate, Q 10 10 kg/sec

Vapor Temperature, T 148 148 C

Total Release Quantity, Q* (Leave Blank if Unlimited) 744200 744200 kg

Liquid or Two-Phase Release Velocity* (Flashing Liquid) m/sec

Initial Fraction Vapor*, f 0 (Flashing Liquid Only) Fraction

kPa absolute

*Note that these inputs may not significantly change results

STEP 4 - Enter Equipment and Plant Layout Information

Equipment and Plant Layout Inputs: Input Value Input Units Equation Input Equation Units

Diameter of Hole or Discharge Piping, d0 m

The hole size for vapor release estimate or diameter of relief system discharge piping. If blank, no jet mixing used.

Release Elevation, h (Blank assumed at Ground) 12 12 m

Release Direction (Assumed Horizontal if Blank)

Enclosed Process Area Volume, VBldg cu m

Enclosed Process Area Ventilation Rate Air Changes/Hr (Assumed 1 if Blank)

For reference in determining

concentration of interest

Leave Blank to accept

Chemical Data Table

Mw

Outdoor

Styrene

Vapor


Blank will not correct for

flammable averaging time.

Vapor Pressure at Release Temp

(Subcooled Liquid Only)




June 28, 2021 Slide - 44

Case Study – LG PolymersEstimate of Actual Styrene Venting for Use in Incident Investigation

416 m to

1000 ppm

162 m to

5000 ppm

There is a densely

populated residential

area downwind of the

release who may have

been exposed to

concentrations in the

range of 1000 to 5000

ppm styrene for one or

more hours duration.

This concentration is in

good agreement with

ALOHA modeling in the

High Power Committee

Report.



June 28, 2021 Slide - 45




With the high population density near the facility, flash fire, toxic impacts or vapor

cloud explosion would all likely yield multiple potential fatalities. Depending on the

specific risk matrix, this would be a very-high consequence severity requiring

several protective layers.

There may be other scenarios associated with Styrene Storage Tank (m6) that

may ultimately need to be addressed through risk analysis to ensure hazard are

managed to within a reasonable tolerable frequency.

June 28, 2021 Slide - 46


Consequence Analysis / Frequency Evaluation



June 28, 2021 Slide - 47

Case Study – LG PolymersSummary of Root Cause Analysis per High Power Committee Report

1. Compliance with Standards: Ineffective Design of Styrene Monomer Storage Tank by

removing suction float.

✓ Unaware of the best practices in Process Safety Information, Management of Change, and Compliance Audits. This

led to thermal stratification within the tank. Unaware of Best Practices in Styrene Monomer Storage and Handling.

2. Inability to understand Process Safety Information and Failure to rectify Standard

Operating Procedures.

✓ Switching off the refrigeration system at 5 PM (Hottest time in the day) is not best practice when polymer can auto

polymerize even at lower temperature and the inhibitor depletes as a function of temperature and time.

✓ Choosing 35 deg C as an acceptable maximum operating condition. This is ineffective Standard Operating Condition

and not recognizing the importance of auto polymerization of Styrene (PSI).

✓ Inability to understand inhibitor depletion characteristics.

✓ Inability to understand High Polymer Content as a precursor for a runaway reaction. An SOP should switch on the

refrigeration system and add TBC when upon high Polymer content. However, no action was observed for three

consecutive days.



June 28, 2021 Slide - 48

3. Improper Hazard Identification

✓ No risk assessment carried out

✓ Failure to understand safeguards

4. Management of Change (Removing suction float)

✓ Did not complete a hazard identification

✓ Unaware of technical basis for change

✓ Did not modify operation procedure and conditions for the change in tank design




June 28, 2021 Slide - 49

5. Emergency Planning and response✓ Onsite emergency plan was inadequate as they did not consider to handle toxic gas release and runaway

reaction

✓ Onsite emergency plan addressed fire and other scenarios.

✓ Inactivation of Siren to inform public. Assumed public and emergency responders were informed.

6. Low Process Safety Competency

✓ Staff at facility had little to no training in Process Safety

7. Deficient Mechanical / Asset Integrity

✓ Refrigeration system was not maintained properly. Visual inspection showed corrosion.

✓ Tank had not been cleaned internally for four years while recommended practice is cleaning every 2 years.




June 28, 2021 Slide - 50

Case Study – LG PolymersRoot Cause – 5 Why


Styrene Vapor Release

1Runaway Reaction

2

Temperature / Inhibitor

Stratification

3

Removal of suction float

[No MOC]4

Plugged s/u d/c piping

5

Deficient Asset Integrity Program



June 28, 2021 Slide - 51

Case Study – LG PolymersRisk Analysis versus Incident Investigation

Seldom does an actual incident match the details of an

anticipated scenario from Risk Analysis. However,

exploration of the differences between anticipated and

actual incident information may help to better understand

“how” and “why” the actual incident occurred and lead to

better Process Risk Management.



Questions?

June 28, 2021 Slide - 52

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