shale oil as steam cracking feedstock -gc × gc ... · gc ×gc characterization and coilsim1d...

Shale oil as steam cracking feedstock:

GC × GC characterization and COILSIM1D modeling

Nenad D. Ristic, Marko R. Djokic, Ismaël Amghizar, Kevin M. Van Geem, Guy B. Marin

2017 AICHE ANNUAL MEETING, 30TH OF OCTOBER 2017

Laboratory for Chemical Technology, Ghent University

OUTLINE

• Introduction

• Shale Oil characterization

• CoilSim1D simulation: Shale Oil as a steam cracking feed

• Conclusions

2/22

INTRODUCTION

Ethane

LPG

Naphtha

Kerosene

Atmospheric Gas Oil

Shale oil

Ethylene

Propylene

1,3-Butadiene

BTX

Heart of a petrochemical plant

The main source of ethylene, propylene and other valuable hydrocarbons

3/22

Molecular

Composition

Validation

Integration ODE

Reactor

Operating Conditions

Reactor Model

Microkinetic Model

Product YieldsProduct YieldsComplex

Feedstock

Complex

Feedstock

METHODOLOGY

Pilot scale

Cracking

Experiments

• Reaction Network

• Thermodynamics

• Kinetics

GC × GC

4/22

OUTLINE

• Introduction



• Conclusions

5/22

ELEMENTAL CONTENT

copper

CO2, H2O, N2, SO2

CO

nickel coated carbon

Flash EA2000 (Interscience, Belgium)

EA

ElementPyrolysis

Shale OilCrude oil [1]

Carbon (wt.%) 81.95 ± 0.16 84.0–87.5

Hydrogen (wt.%) 11.60 ± 0.16 12.5–16.0

Nitrogen (wt.%) 0.03 ± 0.001 0.0–0.5

Sulfur (wt.%) 0.70 ± 0.01 0.01–4.2

Oxygen (wt.%) 5.72 ± 0.04 0.5–1.2

C/H (wt./wt.) 7.06 5.28-6.96

Low sulfur and nitrogen content: 1. Increase in product quality2. Reduced equipment corrosion3. Reduced danger of downstream catalyst poisoning

High oxygen content: 1. Decrease in product quality2. High equipment corrosion

[1] Gawel, M. Eftekhardadkhah, G. Oye, Elemental Composition and Fourier Transform Infrared Spectroscopy Analysis of Crude Oils and Their Fractions, Energy & Fuels, 28 (2014) 997-1003.

6/22

MOLECULAR CHARACTERIZATION

7s7s 7s 7s

1st dimension

separationModulation

2nd dimension

separationDetection

PTV/SSL Injector FID/TOF-MS

Liquid CO2

Volatility

Po

lar

ity

7s 7s 7s 7s

7s

7/22

NON-POLAR × MID-POLAR COLUMN CONFIGURATIONS GC × GC

0

100

200

300

400

0 20 40 60 80 100

b.p.

°C

cumulated wt.%

Naphtha Kerosene Pyrolysis Shale Oil

Volatility

ASTM D2887

Most abundant pure hydrocarbons: paraffins, olefins, cycloalkanes & monoaromatics

Most abundantly present oxygen containing chemical families: ketones, benzenediols, naphthols, phenols and hydroxybenzofurans

The separation of different oxygen containing chemical classes is not adequate, i.e. overlap between phenols and naphthenoaromatics, diaromatics and hydroxybenzofurans, triaromatics and benzenediols

Carbon number ranges from 3 to 26, with a boiling point curve similar to kerosene

8/22

POLAR × NON(MID)-POLAR COLUMN CONFIGURATION GC × GC

Liquid CO2

1st dimension columnStabilwax, Restek, 60 m, 0.25 mm, 0.25 µm

2nd dimension columnRxi-5ms, Restek, 1 m, 0.10 mm, 0.10 µm

Injector FID

Modulator

TOF-MS

1st dimension columnMega-Wax HT, MEGA, 30 m, 0.25 mm, 0.15 µm

2nd dimension columnBPX-50, SGE, 0.6 m, 0.15 mm, 0.15 µm

Detector FID TOF-MS

Column combination 1 2 1 2

Injector PTV SSL

Initial Temperature (°C) 40 320

Ramp (°C min-1) 14.5 -

Final Temperature (°C) 320 320

Split flow (ml min-1) 40 40 10 10

Carrier gas (ml min-1) 1.2 2.4 1.9 3.5

Oven start (°C) 40 40 40 40

Oven end (°C) 260 290 260 290

Ramp (°C min-1) 2 2 2 3

Hold time at oven end (s) 600 600 600 600

Modulation time (s) 14 20 14 20

Detector temperature (°C) 300 -

Detector range (-) 1 -

Detector acquisition rate (Hz)

100 30

Ristic N., Djokic M, Konist A, Van Geem K, Marin G. Quantitative compositional analysis of Estonian shale oil using comprehensive two dimensional gas chromatography, Fuel Processing Technology, 167 (2017) 241–249.

9/22

GC × GC –FID

Polarity & Volatility Polarity & Volatility

Po

lar

ity

Po

lar

ity

Polar × non-polar column configuration improves group type separation of olefins and aliphatic ketones

Oxygenates elute fast off the 2nd D column; however temperature resistance of the Stabilwax column is limiting the complete elution

Polar × mid-polar column configuration improves group type separation of mid-polar and even highly polar oxygen containing compounds

Even oxygenates with the highest boiling point, i.e. alkyl homologues

of benzenediols and hydroxybenzofurans are eluting from the column and can be quantified

Ketones elute together with monoaromatics in both configurations; problem for group type integration

260°C 290°C

Ristic N., Djokic M, Konist A, Van Geem K, Marin G. Quantitative compositional analysis of Estonian shale oil using comprehensive two dimensional gas chromatography, Fuel Processing Technology, 167 (2017) 241–249.

10/22

COMPOSITION OF PYROLYSIS SHALE OIL

0

2

4

6

8

10

12

4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

wt.%

Carbon Number

paraffins isoparaffins

olefins cycloaromatics

mono-aromatics naphtheno-aromatics

di-aromatics naphthenodi-aromatics

tri-aromatics

0

0.5

1

1.5

2

2.5

3

3.5

5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

wt.%

Carbon Number

benzenediols

phenols

naphthols

ketones

hydroxybenzofuranes

other oxygenates

Carbon number ranges from C3 to C26, C<21 account for 95 wt.% of the sample

Olefins and cycloalkanes, with concentrations of 17.5 wt.% and 16.8 wt.% respectively, are the major chemical classes

Oxygen containing compounds mainly belong to the classes of benzenediols, aliphatic ketones, hydroxybenzofurans and phenols with concentrations of 13.4 wt.%, 9.2 wt.%, 9.7 wt.% and 4.1 wt.%, respectively

CO production

Process threats:

1. Unstable feed due to high olefin content

2. Oxygen coupling reaction

3. Equipment corrosion

4. Downstream catalyst poisoning due to high CO production 11/22

OUTLINE

• Introduction



• Conclusions

12/22

COILSIM1D

Integration∫Microkinetic Model

Process Conditions

• Feedstock comp.

• Reactor & Furnace

• Operating conditions

Ω

υ= ∑=

k

n

1kkj

j rdz

dF r

Free-radical mechanism: •• +↔− 2121 RRRR

HRRRHR 2121 −+↔+− ••

321321 RRRRRR −−↔+= ••

Reactor Model

( )∑ ∑ ∆−Ω+ω=j k

krkV,pjj Hrq dzdT

c F

z

uu u

r d

f 2

z

pg

2g

bt

t

d

d

d

d ραρπζα +

+=−

1-D reactor model:

Product yields

CRACKSIM COILSIM1D

0

2

4

6

8

10

12

4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

wt.%

Carbon Number

paraffins isoparaffins

olefins cycloaromatics

mono-aromatics naphtheno-aromatics

di-aromatics naphthenodi-aromatics

tri-aromatics

Length leg I - 10 m

Diameter leg I – 4.5 cm

Wall thickness leg I- 6.0 mm

Length bend I – 23.6 cm

Diameter bend I – 4.5 cm

Wall thickness bend I- 6.0 mm

Length leg II - 10 m

Diameter leg II - 5.5 cm

Wall thickness leg II- 8.0 mm GC × GC

Coil: SC – 2

Coil Outlet Pressure – 1.7 bar

Coil Outlet Temperature – 800°C, 820°C, 840 °C

Steam dilution – 0.5 kg/kgHC, 0.75 kg/kgHC and 1 kg/kgHC

Process Conditions

13/22

PRIM-O NETWORKDeveloped kinetic model consists of two parts:β-network: “describes the thermal decomposition of small molecules”µ-network: “describes the thermal decomposition of large molecules”

µ-hypothesisFor large (C6+) radicals, bimolecular reactions can be neglected

Feed molecule Reaction family

Search for reaction possibilities

Assign reaction rate coefficients

Assign reaction rate coefficients

Generate decomposition reactions

Apply PSSA to µ-radicals

Are all µ-radicalsdecomposed?

Select µ-radical

Generate equivalent single-step reaction

Yes

No

Identify products: molecules, β-radicals, µ-radicals

Identify products: molecules, β-radicals, µ-radicals

k1 k2k3

k4 k5 k6 k7

CC C CC C C *• R,-.,/.,0

RH *k2

k2 * k3 * k4

CC 5 CC C C

*k3

k2 * k3 * k4

IC6H7 * CC • C

*k4

k2 * k3 * k4

k8

k8 * k9

• IC6H: * C4H8

*k4

k2 * k3 * k4

k9

k8 * k9

C 5 CCC C C

*k2

k2 * k3 * k4

*k4

k2 * k3 * k4

k9

k8 * k9

;<4

Inclusion of oxygen containing compounds enables simulating CO yields

Example: decomposition of phenol

S. P. Pyl, C. M. Schietekat, M. F. Reyniers, R. Abhari, G. B. Marin, K. M. Van Geem, “Biomass to olefins: Cracking of renewable naphtha” Chemical Engineering Journal, 176– 177, pp. 178– 187, 2011

K. M. Van Geem, M. F. Reyniers and G. B. Marin, “Challenges of Modeling Steam Cracking of Heavy Feedstocks” Oil & Gas Science and Technology – Rev. IFP, 63, pp. 79-94, 2008

Scheer, A.M., Mukarakate, C., Robichaud, D.J., Nimlos, M.R., Carstensen, H.-H., Barney Ellison, G., 2012. Unimolecular thermal decomposition of phenol and d5-phenol: Direct observation of cyclopentadiene formation via cyclohexadienone. J. Chem. Phys. 136, 044309. 14/22

MODEL VALIDATION

0

5

10

15

20

25

815 820 825 830 835 840 845 850 855

wt.%

COT, °C

Butadiene

Kerosene

0

5

10

15

20

25

30

35

830 835 840 845 850 855 860 865 870

wt.%

COT, °C

Naphtha

Coil Inlet Pressure: 2.0 bar

Coil Outlet Pressure: 1.7 bar

Steam dilution: 0.45 kg/kg HC

Coil Inlet Temperature: 650 °C

Residence time: 0.45 s – 0.52 s

Butadiene

15/22

Simulated steam cracking yields

♦ × Experimentally determined yields

0

5

10

15

20

25

30

795 800 805 810 815 820 825 830 835 840 845

wt.%

COT, °C

0

5

10

15

20

25

30

795 800 805 810 815 820 825 830 835 840 845

wt.%

COT, °C

0

5

10

15

20

25

30

795 800 805 810 815 820 825 830 835 840 845

wt.%

COT, °C

PYROLYSIS SHALE OIL AS STEAM CRACKING CO-FEED

Propylene

0.5 kg/kg

Propylene

Butadiene

0.75 kg/kg

Propylene

Butadiene

1.0 kg/kg

Feedstock: Naphtha (80 wt.%) & Pyrolysis Shale Oil (20 wt.%)




Residence time: 0.2 s

Model prediction naphtha cracking yields

16/22

0

5

10

15

20

25

795 800 805 810 815 820 825 830 835 840 845

wt.%

COT, °C

0

5

10

15

20

25

795 800 805 810 815 820 825 830 835 840 845

wt.%

COT, °C

0

5

10

15

20

25

795 800 805 810 815 820 825 830 835 840 845

wt.%

COT, °C

PYROLYSIS SHALE OIL AS STEAM CRACKING CO-FEED0.5 kg/kg

0.75 kg/kg

1.0 kg/kgFeedstock: Kerosene (80 wt.%) & Pyrolysis Shale Oil (20 wt.%)





Propylene

Butadiene

Propylene

Butadiene

Propylene

Butadiene

Model prediction kerosene cracking yields

17/22

0

5

10

15

20

25

795 800 805 810 815 820 825 830 835 840 845

wt.%

COT, °C

PYROLYSIS SHALE OIL STEAM CRACKING YIELDS

Feedstock: Pyrolysis Shale Oil





Model prediction kerosene cracking yields

0.5 kg/kg

Propylene

Butadiene

0

5

10

15

20

25

795 800 805 810 815 820 825 830 835 840 845

wt.%

COT, °C

Propylene

Butadiene

0.75 kg/kg

0

5

10

15

20

25

795 800 805 810 815 820 825 830 835 840 845

wt.%

COT, °C

Propylene

Butadiene

1.0 kg/kg

18/22

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

795 800 805 810 815 820 825 830 835 840 845

wt.%

COT, °C

CO YIELDS

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

795 800 805 810 815 820 825 830 835 840 845

wt.%

COT, °C





0.5 kg/kg

Naphtha * Pyrolysis Shale Oil

0.75 kg/kg


0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

795 800 805 810 815 820 825 830 835 840 845

wt.%

COT, °C


1.0 kg/kg

Typically CO concentration in the steam cracking unit is lower than approximately 400 ppmw

19/22

OUTLINE

• Introduction



• Conclusions

20/22

CONCLUSIONS• GC × GC enabled detail characterization of oxygen rich pyrolysis shale oil

• Olefins and cycloalkanes, with concentrations of 17.5 wt.% and 16.8 wt.% respectively, are the

major chemical classes

• Carbon number ranges from C3 to C26; the boiling point curve is similar to one characteristic

for kerosene

• CoilSim1D simulations indicated that using shale oil as a steam cracking feed can lead to high

yields of ethylene; higher dilution increases the yields

• Propylene yields are significantly lower compared to ones characteristic for naphtha and

kerosene cracking

• High CO yields are a threat for downstream processes

21/22

ACKNOWLEDGMENTSThank you for your attention!

Long Term Structural Methusalem Funding by the Flemish Government

22/22

GLOSSARYBTX – Benzene, Toluene, XyleneLPG – Liquefied petroleum gas ODE – Ordinary Differential EquationPTV - Programmed Temperature Vaporising injectorS/SL – Split/Splitless injectorGC × GC - comprehensive two-dimensional gas chromatographyFID - Flame Ionization DetectorTOFMS – Time of Flight Mass Spectroscopy COT – Coil Outlet TemperaturePRIM-O - Primary decomposition schemes for hydrocarbons and oxygenates

23/22

GC × GC –NCD/SCDNP-GC × GC –NCD

NP-GC × GC –SCD

Nitrogen compound groups of molecules

Sulfur containing groups ofmolecules

Pyridines Thiols/Sulfides

Anilines Naphthenothiols/Sulfides

QuinolinesDisulfides

IndolesThiophenes

Benzothiophenes

Naphthenobenzothiophenes

Dibenzothiophenes

Measured elemental nitrogen using:

NP-GC × GC –NCDis 0.79 wt.%

EA is 0.79 wt.%

Measured elemental sulfur using:

NP-GC × GC –SCDis 1.09 wt.%

EA is 0.99 wt.%

24/22

PILOT PLANT REACTION SECTION

25/22

shale oil as steam cracking feedstock -gc × gc ... · gc ×gc characterization and coilsim1d...

Documents