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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
Methusalem Advisory Board Meeting, June 19, 2012
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
Methusalem Advisory Board Meeting, June 19, 2012
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
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Methusalem Advisory Board Meeting, June 19, 2012
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
Methusalem Advisory Board Meeting, June 19, 2012
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
Detailed Feedstock Analyses
6
Methusalem Advisory Board Meeting, June 19, 2012
Using comprehensive 2D gas chromatography
Hydrodeoxygenated Tall Oil Fatty Acids (TOFA) HDO-TOFA
GC GC-FID
Fossil vs. Renewable Feedstocks
7
Methusalem Advisory Board Meeting, June 19, 2012
HDO-FAT HDO-TOFARenewable Naphtha
Gas Oil Natural Gas CondensateNaphtha
Steam Cracking Pilot Plant
8
Methusalem Advisory Board Meeting, June 19, 2012
Gas-Fired Furnace + Reactor
Online Analysis Section
Control Room
High temperaturesampling system
HCFeed
H2O
CH4 PAHs
Effect of feedstock on product yields
9
Methusalem Advisory Board Meeting, June 19, 2012
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
Effect of feedstock on run-length
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Methusalem Advisory Board Meeting, June 19, 2012
COT = 850°C
ReferenceFeedstocks
Pilot plant cokes test Cokes formation during 6-h steady state operation
RenewableFeedstocks
To d
o …
Outline
11
Methusalem Advisory Board Meeting, June 19, 2012
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
Reactor and Kinetic Modeling
12
Methusalem Advisory Board Meeting, June 19, 2012
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
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Methusalem Advisory Board Meeting, June 19, 2012
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
14
Methusalem Advisory Board Meeting, June 19, 2012
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
Coil Outlet Temperature [ C]
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
Methusalem Advisory Board Meeting, June 19, 2012
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
Coil Outlet Temperature [ C]
1-pentene
1-butene
Outline
16
Methusalem Advisory Board Meeting, June 19, 2012
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
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
Methusalem Advisory Board Meeting, June 19, 2012
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Methusalem Advisory Board Meeting, June 19, 2012
Thank you foryour attention!
Glossary
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Methusalem Advisory Board Meeting, June 19, 2012
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).