Introduction
Pyrolysis oil (from fast pyrolysis of lignocellulosic biomass) is an attractive energy carrier, since it is renewable and easy to transport.
Hydrotreatment with Ru/C has been proved to improve the quality of the pyrolysis oil, so it can be used as co-feeding for existing refineries.
Mechanism of hydrotreatment, and mass transfer effects, are not fully understood.
Background Hypothesis: hydrotreatment pathway
(Venderbosch, et al , 2010)
Understanding the mechanism of hydrotreatment with Ru/C, and possible mass transfer effects (G/L, L/S)
Objectives
Experiment Set-Up
Feed: 25 g of pine pyrolysis oil, catalyst: Ru/C, starting H2 pressure: 120 bar at room temperature
Severity (T,t): from 80 oC (1 h) to 80 oC (1h)+150 oC (1h) + 350 oC (2h)
Catalyst intake: 1 – 5 wt% of feed
Catalyst particle size: 23 μm – 525 μm
Variables:
Conditions:
Conditions:
Catalyst intake
Large catalyst particle size resulted in low catalyst activity, low H/C ratio of organic phase, and catalyst activity.
Indication that the reaction occurs mainly on the surface of the catalyst particle.
Autoclave, batch mode, 100 ml volume
Set-up
Hydrotreatment pathway
Reactor
N2 Bomb
Feed line
N2
H2
I-2
Gas outlet
P & T Recorder
PO
P-1
Analysis: Van Krevelen plot (O/C vs H/C), H2 consumption, Mw.
Desired properties: high H/C and low Mw of the organic phase. High H2 uptake indicates high catalyst activity.
Products: Gas (CO2, CH4, C2 – C3), organic phase (upgraded oil),
aqueous phase
Catalyst particle size
Severity 1 Severity 2 Severity 3 Severity 4 Severity 5
80 o C (1h) 80 o C (1h) +150 oC (1h)
80 o C (1h) +150 oC (1h) +250 oC (1h)
80 o C (1h) +150 oC (1h) +350 oC (1h)
80 o C (1h) +150 oC (1h) +350 oC (2h)
1.35 1.40 1.45 1.50 1.550.1
0.2
0.3
0.4
0.5
0.6
Severity 5
Severity 4
Severity 3
Severity 2
Severity 1
Ato
mic
O/C
ra
tio (
dry
)
Atomic H/C ratio (dry)
Pyrolysis oil
Pathway:
1.2 1.3 1.4 1.5 1.60.0
0.1
0.2
0.3
0.4
0.5
0.6
513 m 50 m 23 m
Pyrolysis oil
Ato
mic
O/C
ratio
(dry
)
Atomic H/C ratio (dry)
1.2 1.3 1.4 1.5 1.60.0
0.1
0.2
0.3
0.4
0.5
0.6
5 wt%
2 wt%1 wt%
Pyrolysis oil
Ato
mic
O/C
rat
io (
dry)
Atomic H/C ratio (dry)
High catalyst intake gave lower H2 uptake (per g active metal)
At high catalyst intake, the order of reaction ≠ 1 with respect to catalyst concentration.
Pyrolysis Oil
T>175 oC, non catalytic, fast
Re-polymerisation High mol. fragments
non-polar fragments, aqueous phase
non-polar fragments (low Mw), aqueous phase
Hydrocracking
+H2 200 bar, catalyst,
T > 250 oC
+H2 200 bar, catalyst, T > 250 oC
Pyrolysis Oil
+H2, catalyst, T > 80 oC
T>175 oC, non catalytic, fast
Hydrogenation
Re-polymerisation
Stable fragments
High mol. fragments
Hydrodeoxygenation non-polar fragments, aqueous phase+H2 200 bar, catalyst,
T > 250 oC
non-polar fragments (low Mw), aqueous phase
Hydrocracking
+H2 200 bar, catalyst,
T > 250 oC
CharCharring
T>175 oC, non catalytic, fast
+H2 200 bar, catalyst, T > 250 oC
Pyrolysis oil Severity 1 Severity 2 Severity 3 Severity 4 Severity 50
50
100
150
200
250
300
Mw o
f org
an
ic p
ha
se (
g/m
ol)
Severity
350
400
450
500
550
600
650
700
750
800
850
H2 u
pta
ke (
NL
/kg
fee
d)
Mw
H2 uptake
0.00 0.01 0.02 0.03 0.04 0.050
50
100
150
200
250
300
A
ctiv
ity (g
act
ive
met
al
-1)
1/dp (m-1)
150
200
250
300
350
400
450M
w o
f org
anic
pha
se (g
/mol
)
23 m
50 m
513 m
Mw
Catalyst activity
1 2 3 4 50
1x105
2x105
3x105
4x105
H2 u
ptak
e/kg
feed
.g a
ctiv
e m
etal
(NL.
kg
-1.g
-1)
Mw o
f org
anic
pha
se (g
/mol
)
Catalyst intake (wt% of feed)
300
350
400
450
500
H2 uptake
Mw
Catalytic hydrotreatment of pyrolysis oil with heterogeneous Ru/C catalysts: Insight in pathway and
mass transfer effectsA.R. Ardiyanti1, J. E. S. Westra1, F. de Miguel Mercader2, R. H. Venderbosch3, J. A. Hogendoorn2, H. J. Heeres1
Catalytic hydrotreatment of pyrolysis oil with heterogeneous Ru/C catalysts: Insight in pathway and
mass transfer effectsA.R. Ardiyanti1, J. E. S. Westra1, F. de Miguel Mercader2, R. H. Venderbosch3, J. A. Hogendoorn2, H. J. Heeres1
(1) Chemical Engineering Department, University of Groningen, The Netherlands(2) Thermo-Chemical Conversion of Biomass Group, University of Twente, The Netherlands(3) BTG Biomass Technology Group BV, Enschede, The NetherlandsFurther information: [email protected]
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