Download pdf - Biomass to Olefins: Steam Cracking of … · Biomass to Olefins: Steam Cracking of RenewableFeedstocks. Outline 2 ... Renewable Naphtha Steam Cracking 15 Methusalem Advisory Board

Laboratory for Chemical Technology, Ghent University

http://www.lct.UGent.be

Steven P. Pyl

1

Methusalem Advisory Board Meeting, June 19, 2012

Biomass to Olefins:

Steam Cracking of Renewable Feedstocks

Outline

2


Pilot Plant Steam Cracking of Hydrodeoxygenated Biomass

Feedstock analyses

Effect of feedstock on product yields

Effect of feedstock on run-length

Introduction: Green Olefins

Conclusions

Reactor and Kinetic modeling

Effect of Coil Outlet Temperature on product yields

Poultry Fat to Olefins

3


Hydrocracking

+ FractionationGREEN

OLEFINS

Steam Cracking

Steam Cracking

LPG (C3-C4)Jet Fuel (C10-C15)

HDO – FAT(C14-C26 n-Paraffins)

Renewable Naphtha(C4-C10)

CO, CO2, H2O

Hydro-deoxygenation

Poultry Fat & YellowGrease

Tall Oil to Olefins

4


TOFA

DTO

Heads

Pitch

Crude Tall Oil Refining

Pine Wood

Kraft PulpingProcess

Wood Pulp

CrudeTall Oil

TOFA

GREEN OLEFINS

HDO – TOFA(C14-C26 n-Paraffins)

Hydro-deoxygenationTOFA

SteamCracking

Outline

5



Feedstock analyses




Conclusions



Detailed Feedstock Analyses

6


Using comprehensive 2D gas chromatography

Hydrodeoxygenated Tall Oil Fatty Acids (TOFA) HDO-TOFA

GC GC-FID

Fossil vs. Renewable Feedstocks

7


HDO-FAT HDO-TOFARenewable Naphtha

Gas Oil Natural Gas CondensateNaphtha

Steam Cracking Pilot Plant

8


Gas-Fired Furnace + Reactor

Online Analysis Section

Control Room

High temperaturesampling system

HCFeed

H2O

CH4 PAHs


9


Yields [wt%]δ = 0.45kg/kg

Full-range Naphtha

RenewableNaphtha

HDO-FAT HDO-TOFA

Methane 16.9 17.6 11.0 10.4

CO 0.08 0.17 0.15 0.11

CO2 0.01 0.02 0.07 0.08

P/E = 0.50

COT 870°C 865°C 835°C 820°C

Fuel Oil 1.54 0.56 0.27 8.57

ReferenceFeedstock

Renewable Feedstocks

Benzene 9.74 6.11 5.23 4.35

Toluene 4.59 2.50 1.49 1.42

Xylenes 1.35 0.54 0.18 0.26

Ethylene 26.5 32.0 38.4 35.4

Propylene 13.1 16.4 19.5 18.2

1,3-butadiene 5.41 5.03 7.77 6.41

3.5

5.55

2.5

4.4

5.8

0

1

2

3

4

5

6

7

RenewableNaphtha

HDO-FAT HDO-TOFA Ethane PetroleumNaphtha

Natural GasCondensate

g co

kes

/ 6 h


10


COT = 850°C

ReferenceFeedstocks

Pilot plant cokes test Cokes formation during 6-h steady state operation

RenewableFeedstocks

To d

o …

Outline

11



Feedstock analyses




Conclusions



Reactor and Kinetic Modeling

12


Concentration Profiles & Product YieldsTemperature and Pressure Profile

System of Differential Equations

Microkinetic Model

Feedstock Composition

Reactor Geometry

Operating Conditions

Free RadicalMechanism

•• +↔− 2121 RRRR

HRRRHR 2121 −+↔+− ••

321321 RRRRRR −−↔+= ••

numericalintegration

Ω

υ= ∑=

k

n

1kkj

j rdz

dF r

( )∑ ∑ ∆−Ω+ω=j k

krkV,pjj Hrq dzdT

c F

zu

u u r d

f 2zdpd

g2

g

bt

t

∂∂ρα+ρ

πζ+α=−

Plug flow

Reactor Model

Single-event Microkinetic Model

13


Microkinetic Model1. Automatic reaction network generation

2. Group-additive calculation of rate coefficients

3. Quasi steady state approximation for µ radicals

4. In situ lumping of primary products

5. A posteriori lumping of feed molecules

51 paraffins168 olefins14 aromatics43 radicals

276 species

C0 – C26C2 – C26C6 – C14C0 – C70

C0 – C26

0

1

2

3

4

5

6

7

8

9

740 760 780 800 820 840 860 880

Yie

ld [w

t%]

benzene

toluene

naphthalene

0

2

4

6

8

10

12

14

16

740 760 780 800 820 840 860 880

Yie

ld [w

t%]

Coil Outlet Temperature [ C]

methane

ethane

propane

HDO-FAT Steam Craking

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simulated yields (lines) vs.pilot plant yields (symbols)

δ = 0.45 kg/kg

Coil Outlet Temperature (COT)755°C 865°C

0

5

10

15

20

25

30

35

40

45

740 760 780 800 820 840 860

Yie

ld [w

t%]

ethene

propene

1.3-butadiene


0

1

2

3

4

5

6

7

8

760 780 800 820 840 860 880 900

Yie

ld [w

t%]

benzene

naphthalene

toluene

0

5

10

15

20

25

30

35

40

760 780 800 820 840 860 880 900

Yie

ld [w

t%]

ethene

propene

1,3-butadiene

Renewable Naphtha Steam Cracking

15


simulated yields (lines) vs.pilot plant yields (symbols)

δ = 0.45 kg/kg

Coil Outlet Temperature (COT)820°C 860°C

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

760 780 800 820 840 860 880 900


1-pentene

1-butene

Outline

16



Feedstock analyses




Conclusions



Conclusions

• Biowaste is a promising starting material for the production of green olefins

• Hydrodeoxygenation of waste fats as well as tall oilsproduces highly paraffinic liquids

• Steam cracking of these liquids results in high light olefin yields

• Microkinetic modeling provides a rigorous fundamental basis for industrial reactor models

17


18


Thank you foryour attention!

Glossary

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Biowaste A variety of renewable animal and vegetal waste streamsarising from households, commerce and the foodmanufacturing industry.

Comprehensive two-dimensional gas chromatography

Advanced analytical technique that provides two-dimensional separation by combining two differentanalytical columns connected with an interface, calledthe modulator, that ensures that the entire sample iscomprehensively subjected to both separations.

Group additive framework Framework that enables automated calculation ofthermodynamic or kinetic data from the structure of themolecule or transition state respectively by summation ofgroup-additive values.

Hydrodeoxygenation A catalytic process which, in the presence of hydrogen,removes oxygen from organic components in the form ofwater. Common side-reactions are decarboxylation anddecarbonylation producing carbon dioxide and carbonmonoxide respectively.

Tall oil A viscous yellow-black odorous liquid obtained as a by-product of the Kraft process of wood pulp manufacturewhen pulping mainly coniferous trees. The nameoriginated as an Anglicization of the Swedish "tallolja"("pine oil"). Crude tall oil can be fractionated into severalfractions, including so-called tall oil fatty acids (TOFA)and distilled tall oil (DTO).