Is Rust a Problem?  Screening of (Oxygenated) Hydrocarbon Reactivity

Nick Gonzales, Marc Levin, and Hector ZamoraShell Global Solutions (US) Inc.

Mary Kay O’Connor Process Safety CenterAnnual Symposium

Fall 2007

Copyright 2005 by Shell Global Solutions (US) Inc. This document is made available subject to the condition that the recipient will neither use nor disclose the contents except as agreed in writing with the copyright owner.

Outline

• Background• Experimental Description• Experimental Results for Species with Rust • Summary

• Rust – normally iron(III) oxide - is commonly found in petrochemical processing equipment

• Fines/deposits can provide significant surface area

• Potential exists for rust to react with or catalyze reaction of process species

• Screening of reactivity with such contaminants can be easily overlooked

Background

APTACTM

Automatic Pressure Tracking

Adiabatic Calorimeter

APTAC is a trademark of TIAX, LLC

Sample

Stirring Magnet

Ceramic Insulation

Pressure Vessel

Pressure & Temperature Controlled Chamber

Reaction Vessel

Heaters

Nitrogen TC

Sample TC

Controlled Vent

Gas/Liquid Injection P Transducer

Experimental Details• APTAC• Air purged

- Vacuum/N2 addition- N2 pressure/venting

• Nitrogen pad gas (except forethylene tests)

• Iron(III) oxide (“rust”)- Loaded into basket (C2H4;EO)- Poured into cell

Titanium cell

TeflonTM-coated stir bar

sample

TC

Systems Studied

Ethylene (1-170 m -Fe2O3 powder) Ethylene Oxide (1-170 m -Fe2O3 powder) Cumene Hydroperoxide (< 5 m -Fe2O3) Di-tert-Butyl Peroxide (< 5 m -Fe2O3) Ethylene Glycol (< 5 m -Fe2O3) Diethylene Glycol (< 5 m -Fe2O3) Hydrogen Peroxide (< 5 m -Fe2O3)• (Diethyl Hydroxyl Amine – not yet tested)

In some systems, reaction with other iron oxides (e.g., FeO) was also examined

Ethylene + Iron (III) Oxide, Iron(II) Oxide Temperature Histories @ constant pressure

0

100

200

300

400

500

600

700

800

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000

Time [min]

Tem

pera

ture

[ C

]

Ethylene @ 660 psia (A00638)Ethylene @ 1561 psig (A00639a)Ethylene @ 1799 psig (A00645)Ethylene @1952 psig (A00644)Ethylene + Iron (III) Oxide @ 1330 psig (A00701)Ethylene + Iron (III) Oxide @ 1580 psig (A00702)Ethylene + Iron (II) Oxide @ 1630 psig (A00704)

Heat-Wait-Search StepExotherm

Ethylene + Iron (III) Oxide , Iron(II) Oxide Self-Heat Rates @ constant pressure

700600200 400300160 18014020 40 60 10080 120 5000.01

0.1

1

10

100

1000

10000

-3.5 -3.0 -2.5 -2.0 -1.5 -1.0

-1000/T [K-1]

dT/d

t [ C

/min

]

Ethylene @ 660 psia (A00638)Ethylene @ 1561 psig (A00639a)Ethylene @ 1799 psig (A00645)Ethylene @1952 psig (A00644)Ethylene + Iron (III) Oxide @ 1330 psig (A00701)Ethylene + Iron (III) Oxide @ 1580 psig (A00702)Ethylene + Iron (II) Oxide @ 1630 psig (A00704)

C

Heat-Wait-Search Step

Exotherm

Ethylene + Iron (III) Oxide , Iron(II) Oxide Self-Heat Rates @ constant pressure

40030020 80 120 160 50040 20060 100 140 180 6000.01

0.1

1

10

100

1000

10000

-1000/T [K-1]

dT/d

t [ C

/min

]

Ethylene @ 1561 psig (A00639a)Ethylene @ 1799 psig (A00645)Ethylene @1952 psig (A00644)Ethylene + Iron (III) Oxide @ 1330 psig (A00701)Ethylene + Iron (III) Oxide @ 1580 psig (A00702)Ethylene + Iron (II) Oxide @ 1630 psig (A00704)

C

Exotherm threshold

Ethylene + Iron (III) Oxide , Iron(II) Oxide

Comments:L. Britton (UCC): referred to exotherm onset

temperature as low as 100°C (data not presented in ethylene paper). This was “occasionally” observed.

At this point, it is not clear why lowering of the onset temperature did not occur in our tests.

TEMPERATURE-TIME HISTORY OF ETHYLENE OXIDE + IRON OXIDEAPTAC Experiments

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

850

900

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800

Time [min]

Tem

pera

ture

[°C

]

20 g EO + 0.5 g alpha-Fe3O4 (A00507)

20 g EO + 0.5 g alpha-Fe3O4 (A00510)

20 g EO + 0.5 g alpha-Fe2O3 (A00370)

20 g EO + 0.5 g hydrated alpha-Fe2O3 (A00367)

20 g EO + 0.5 g gamma-Fe2O3 (A00362)

20 g EO + 0.5 g gamma-Fe2O3 (A00363)

20 g EO + 0.5 g gamma-Fe2O3 (A00373)

Ethylene Oxide + Iron OxidesTemperature Histories

PRESSURE-TIME HISTORY OF ETHYLENE OXIDE + IRON OXIDEAPTAC Experiments

0

200

400

600

800

1000

1200

1400

1600

1800

2000

2200

2400

2600

2800

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800

Time [min]

Pre

ssur

e [p

sia]

20 g EO + 0.5 g alpha-Fe3O4 (A00507)

20 g EO + 0.5 g alpha-Fe3O4 (A00510)

20 g EO + 0.5 g alpha-Fe2O3 (A00370)

20 g EO + 0.5 g hydrated alpha-Fe2O3 (A00367)

20 g EO + 0.5 g gamma-Fe2O3 (A00362)

20 g EO + 0.5 g gamma-Fe2O3 (A00363)

20 g EO + 0.5 g gamma-Fe2O3 (A00373)

Ethylene Oxide + Iron OxidesPressure Histories

600 700200180 4003001604020 60 80 120100 140 5000.01

0.1

1

10

100

1000

10000

-1000/T [K-1]

dT/d

t [°C

/min

]

20 g EO + 0.5 g alpha-Fe3O4 (A00507)20 g EO + 0.5 g alpha-Fe3O4 (A00510)20 g EO + 0.5 g alpha-Fe2O3 (A00370)20 g EO + 0.5 g hydrated alpha-Fe2O3 (A00367)20 g EO + 0.5 g gamma-Fe2O3 (A00362)20 g EO + 0.5 g gamma-Fe2O3 (A00363)20 g EO + 0.5 g gamma-Fe2O3 (A00373)

°C

Exotherm

Exotherm Threshold

Ethylene Oxide + Iron OxidesSelf-Heat Rates

500140100 120806020 40 160 300 400180 200 7006000.01

0.1

1

10

100

1000

10000

-1000/T [K-1]

dP/d

t [p

si/m

in]

20 g EO + 0.5 g alpha-Fe3O4 (A00507)

20 g EO + 0.5 g alpha-Fe3O4 (A00510)

20 g EO + 0.5 g alpha-Fe2O3 (A00370)

20 g EO + 0.5 g hydrated alpha-Fe2O3 (A00367)

20 g EO + 0.5 g gamma-Fe2O3 (A00362)

20 g EO + 0.5 g gamma-Fe2O3 (A00363)

20 g EO + 0.5 g gamma-Fe2O3 (A00373)

°C

Ethylene Oxide + Iron OxidesPressurization Rates

0

100

200

300

400

500

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400

Time [min]

Tem

pera

ture

[ C

]

30%w CHP/Cumene (A00874)

30%w CHP/Cumene + 1.26%w Rust (A00855)

Heat-Wait-Search Step

Exotherm

30%w CHP/cumene + Iron(III) OxideTemperature Histories

0

100

200

300

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400

Time [min]

Pres

sure

[psi

a]

30%w CHP/Cumene (A00874)

30%w CHP/Cumene + 1.26%w Rust (A00855)

30%w CHP/cumene + Iron(III) OxidePressure Histories

500140100 120806020 160 300 400180 200400.01

0.1

1

10

100

1000

10000

-3.5 -3.0 -2.5 -2.0 -1.5 -1.0

-1000/T [K-1]

dT/d

t [

C/m

in]

30%w CHP/Cumene (A00874)

30%w CHP/Cumene + 1.26%w Rust (A00855)

C

Exotherm detected

Heat-Wait-Search Step

30%w CHP/cumene + Iron(III) OxideSelf-Heat Rates

40 200180 40030016020 60 80 120100 140 500 7006000.001

0.01

0.1

1

10

100

1000

10000

-1000/T [K-1]

dP/d

t [p

si/m

in]

30%w CHP/Cumene (A00874)

30%w CHP/Cumene + 1.26%w Rust (A00855)

C

30%w CHP/cumene + Iron(III) OxidePressurization Rates

0

100

200

300

400

500

0.01 0.1 1 10 100 1000 10000

Time to Maximum Rate [min]

Tem

pera

ture

[ C

]

30%w CHP/Cumene (A00874)

30%w CHP/Cumene + 1.26%w Rust (A00855)

30%w CHP/cumene + Iron(III) OxideTime to Maximum Rate

0

100

200

300

400

500

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800

Time [min]

Tem

pera

ture

[ C

]

20%w DTBP in Toluene (A00575)

20%w DTBP in Toluene + 0.81%w Rust (A00871)

Heat-Wait-Search Step

Exotherm

20%w DTBP/Toluene + Iron(III) OxideTemperature Histories

0

100

200

300

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800

Time [min]

Pres

sure

[psi

a]

20%w DTBP in Toluene (A00575)

20%w DTBP in Toluene + 0.81%w Rust (A00871)

20%w DTBP/Toluene + Iron(III) OxidePressure Histories

40 200180 40030016020 60 80 120100 140 5000.01

0.1

1

10

100

1000

-3.5 -3.0 -2.5 -2.0 -1.5 -1.0

-1000/T [K-1]

dT/d

t [

C/m

in]

20%w DTBP in Toluene (A00575)

20%w DTBP in Toluene + 0.81%w Rust (A00871)

C

Exotherm detected

Heat-Wait-Search Step

20%w DTBP/Toluene + Iron(III) OxideSelf-Heat Rate

40 200180 40030016020 60 80 120100 140 500 7006000.001

0.01

0.1

1

10

100

1000

10000

-1000/T [K-1]

dP/d

t [p

si/m

in]

20%w DTBP in Toluene (A00575)

20%w DTBP in Toluene + 0.81%w Rust (A00871)

C

20%w DTBP/Toluene + Iron(III) OxidePressurization Rate

0

100

200

300

400

500

0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400

Time [min]

Tem

pera

ture

[°C

]

Ethylene Glycol (A00824)

Ethylene Glycol + 1.27%w Rust (A00870)

Heat-Wait-Search Step

Exotherm

Ethylene Glycol + Iron(III) OxideTemperature Histories

0100200300400500600700800900

10001100120013001400150016001700180019002000

0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400

Time [min]

Pres

sure

[psi

a]

Ethylene Glycol (A00824)

Ethylene Glycol + 1.27%w Rust (A00870)

Ethylene Glycol + Iron(III) OxidePressure Histories

40 200180 40030016020 60 80 120100 140 5000.01

0.1

1

10

100

-3.5 -3.0 -2.5 -2.0 -1.5 -1.0

-1000/T [K-1]

dT/d

t [

C/m

in]

Ethylene Glycol (A00824)

Ethylene Glycol + 1.27%w Rust (A00870)

C

Ethylene Glycol + Iron(III) OxideSelf-Heat Rates

40 200180 40030016020 60 80 120100 140 500 7006000.001

0.01

0.1

1

10

100

1000

-1000/T [K-1]

dP/d

t [p

si/m

in]

Ethylene Glycol (A00824)

Ethylene Glycol + 1.27%w Rust (A00870)

C

Ethylene Glycol + Iron(III) OxidePressurization Rates

0

100

200

300

400

500

0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400

Time [min]

Tem

pera

ture

[ C

]

DEG (A00869)

DEG + 1.25%w Rust (A00868)

Heat-Wait-Search Step

Exotherm

Diethylene Glycol + Iron(III) OxideTemperature Histories

0100200300400500600700800900

1000110012001300140015001600170018001900200021002200

0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400

Time [min]

Pres

sure

[psi

a]

DEG (A00869)

DEG + 1.25%w Rust (A00868)

Diethylene Glycol + Iron(III) OxidePressure Histories

500140100 120806020 160 300 400180 200400.01

0.1

1

10

100

1000

-3.5 -3.0 -2.5 -2.0 -1.5 -1.0

-1000/T [K-1]

dT/d

t [

C/m

in]

DEG (A00869)

DEG + 1.25%w Rust (A00868)

C

Diethylene Glycol + Iron(III) OxideSelf-Heat Rates

40 200180 40030016020 60 80 120100 140 500 7006000.001

0.01

0.1

1

10

100

1000

-1000/T [K-1]

dP/d

t [p

si/m

in]

DEG (A00869)

DEG + 1.25%w Rust (A00868)

C

Diethylene Glycol + Iron(III) OxidePressurization Rates

0

100

200

300

400

500

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400

Time [min]

Tem

pera

ture

[ C

]

30%w H2O2/Water (A00719)

30%w H2O2/Water (A00881)

30%w H2O2/Water + 1.26%w Rust (A00883)

Hydrogen Peroxide + Iron(III) OxideTemperature Histories

Hydrogen Peroxide + Iron(III) OxidePressure Histories

0100200300400500600700800900

10001100120013001400150016001700180019002000

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400

Time [min]

Pres

sure

[psi

a]

30%w H2O2/Water (A00719)

30%w H2O2/Water (A00881)

30%w H2O2/Water + 1.26%w Rust (A00883)

Hydrogen Peroxide + Iron(III) OxideSelf-Heat Rates

40 200180 40030016020 60 80 120100 140 5000.01

0.1

1

10

100

1000

-3.5 -3.0 -2.5 -2.0 -1.5

-1000/T [K-1]

dT/d

t [

C/m

in]

30%w H2O2/Water (A00719)

30%w H2O2/Water (A00881)

30%w H2O2/Water + 1.26%w Rust (A00883)

C

Hydrogen Peroxide + Iron(III) OxidePressurization Rates

40 200180 40030016020 60 80 120100 140 5000.001

0.01

0.1

1

10

100

1000

10000

-1000/T [K-1]

dP/d

t [p

si/m

in]

30%w H2O2/Water (A00719)

30%w H2O2/Water (A00881)

30%w H2O2/Water + 1.26%w Rust (A00883)

C

Hydrogen Peroxide + Iron(III) OxideTime to Maximum Rate

0

100

200

300

400

500

0.01 0.1 1 10 100 1000 10000

Time to Maximum Rate [min]

Tem

pera

ture

[ C

]

30%w H2O2/Water (A00719)

30%w H2O2/Water (A00881)

30%w H2O2/Water + 1.26%w Rust (A00883)

Summary

Of the systems examined, iron(III) Oxide (“rust”) significantly affects only EO.

Marginal impact seen for CHP

Surprisingly, no significant effect on ethylene

Large effect observed for H2O2

Overall conclusion: rust enhances reaction for species that are known for instability or reactivity

Summary

Future InterestContinued testing

• Additional species with -Fe2O3

• Species with FeO• Species with high surface area Fe