Catalytic conversion of pyrolysis gas in the WoodRoll
process for enhanced process reliability
Pouya H. Moud1), Dennis Fällén Holm1), Alfred Halvarsson1), Klas Andersson2),
Efthymios Kantarelis1), Marko Amovic3), Rolf Ljunggren3), Klas Engvall1)
1) KTH, Dept of Chemical Engineering, Stockholm
2) Haldor Topsoe A/S, Kgs. Lyngby, Denmark
3) Cortus Energy AB, Kista
Nyheter och forskningsresultat om energigas 8-9 June 2017, Göteborg
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Scope of study
The scope of the project was to perform an early
evaluation of a technical solution, based on a
catalytic conversion, simplifying the conveying
of the pyrolysis gas in pipelines and valves, as
well as improve combustion properties in the
radiant heat tube burners.
”Raw
pyrolysis
gas with
35-40% oil”
Filter
Pyrolytic
residues
Catalytic
reactor
”Energy
gas with
lighter
CxHy”
Burners
Outline
1.
2.
3.
4.
5.
6.
Cortus Energy
The WoodRoll® technology
Experimental tests and methods
Results enhanced process reliability
Other potential applications
Summary
3
1. Cortus Energy
Cortus Energy
• Founded in 2006 to develop and
commercialize the patented gasification
process WoodRoll®.
• WoodRoll® is a gasification process for
biomass, producing clean energy gas with a
high energy value.
• The purity and high energy value of the energy
gas makes it suitable for replacing fossil fuels.
• Listed on Nasdaq OMX First North since
february 2013.
• The company has 12 employees and 10
consultants.
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2. The WoodRoll® technology
The WoodRoll® technology
Tar free
product
gas
The WoodRoll® technology
Biofuels
Drying
Pyrolysis
Gasification
• 20 biofuels verified
• Controlled dusting
and condensate
• Single percentage
humidity in operation
• Combustion stable
• Char yield [T, Xi]
35% ±10%
• Pyrolysis oil yield 35%
±10%
• >99% Conversion
rate reached
• Ash melting only for
chemical sludge
• Clean product gas
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3. Experimental setup
and methods
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Experimental setup and methods
Pyrolytic
residues
”Raw
pyrolysis
gas”
Filter
450 °C
”Filtered raw
pyrolysis gas”
Catalytic
reactor
450 °C
T1
”Treated
pyrolysis gas”
.
.
.
.
.
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•
Experiments on-site in Köping
•
Wood chips of GROT
•
Real biomass pyrolysis gas including bio-crude
•
Sampling before and after catalytic reactor
•
Tests included Fe-based material and dolomite mineral as
catalysts
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Experimental setup and methods
Pyrolysis gas line
Pyrolyser
Burner
Permanent
gases and
oil samples
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Experimental setup and methods
Pyrolysis oil sampling
Basic evaluation
• Permanent gas analysis
• Bio-crude analyses
- Gravimetric
- C/H/O
• Catalyst characterization
-
Surface area
Carbon laydown
TPO
XRD
• Mass balance evaluation
for C,H,O
Extended analysis
• Bio-crude analyses
- H-NMR
- GC/MS
• Proposed mechanism
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4. Results enhanced
process reliability
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Experimental conditions
Experimental conditions using Fe-based catalyst
Catalyst volume
1 dm3
Initial stabilization period, reactor inlet temperature
8-hour test, reactor inlet temperature
8-hour test, catalyst bed inlet temperature
8-hour test, catalyst bed exit temperature
Inlet pyrolysis gas flow rate, N2-free
400°C
440°C
412°C
450°C
1.11 Nm3/h
Nitrogen flowrate
0.31 Nm3/h
Space velocity (N2-free)
1100 h-1
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•
The pyrolysis gas was treated under stable conditons for 8 hours
with the iron-based catalyst
•
The dolomite bed collapsed totally after 30 minutes of use
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Operational stability catalytic bed
T-profile inside the reactor versus time on stream
Stable operation
Initial activation
500
500
TC
480
480
for the second time
TC
460
460
440
440
TC
T (C)
T (C)
bottom T
Top T
inlet gas T
100% pyrolysis flow introduced
TC
420
420
TC
400
400
TC
380
360
380
TC
360
TC
TC
100% pyrolysis flow introduced
catalytic bed bottom T
catalytic bed top T
reactor inlet gas T
for the first time
340
0
25
50
75
100
Time on stream (min)
•
•
•
•
125
150
0
20
40
60
80
100
ToS (min)
Successful activation of the catalyst
Fluctuation in temperature due to initial activation
Stable T-profiles after activation
Catalytic effect remained despite surface S and C
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Permanent gases
Average molar flow rates of permanent gases
Pyrolytic
residues
• A significant increase of hydrogen
• Increase in H2 and CO2 content
WGS activity
”Raw
pyrolysis
gas”
Filter
450 °C
”Filtered raw
pyrolysis gas”
Catalytic
cracker
450 °C
T1
”Treated
pyrolysis gas”
.
.
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T7
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Mass distribution and bio-crude analysis
Mass distribution
C/H/O analysis (dry basis), water content, S/C, O/C,
and H/C of the raw and treated solvent-free condensate
Raw
condensate
Treated
condensate
Water
S/C of
content in condensate
condensate (mol/mol)
(wt-%)
C (wt%), db
H (wt%), db
O (wt%), db
50.3
4.9
44.8
20
59.3
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35.7
44.3
O/C of
condensate
(mol/mol)
H/C of
condensate
(mol/mol
0.33
0.99
1.84
0.90
1.34
2.81
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Pyrolytic
residues
• 51% reduction in bio-crude content
• Decrease in oxygen content
• Increase in S/C ratio => lower carbon
formation on catalyst
”Raw
pyrolysis
gas”
Filter
450 °C
”Filtered raw
pyrolysis gas”
Catalytic
cracker
450 °C
T1
”Treated
pyrolysis gas”
.
.
.
.
.
T7
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Burner performance
Pyrolytic
residues
”Raw
pyrolysis
gas”
Filter
450 °C
”Filtered raw
pyrolysis gas”
Catalytic
cracker
450 °C
T1
”Treated
pyrolysis gas”
.
.
.
.
.
T7
• More rapid combustion of the
treated pyrolysis gas, resulting in a
more evenly distributed
temperature profile.
• Combustion zone for treated oil is
longer than raw oil.
Burner performance
Pyrolytic
residues
”Raw
pyrolysis
gas”
Filter
450 °C
”Filtered raw
pyrolysis gas”
Catalytic
cracker
450 °C
T1
”Treated
pyrolysis gas”
.
.
.
.
.
T7
800
700
(ppm)
600
500
400
300
200
100
0
NOX/NO
Crude pyrolysis gas
Treated pyrolysis gas 100%
NO
Treated pyrolysis gas 70%
• Lower NOx implies a more uniform
combustion
5. Other potential applications
A step for pre-conditioning
Biomass
• The change of pyrolysis oil to lighter hydrocarbons, the
lowering of oxygen content and the change in
permanent gases implies a possible use of the as a
pre-conditioning step.
• Evaluation point at dehydration/decarbonylation of
hydrocarbons followed by a subsequent water-gas shift
reaction
• Paper describing in-depth analysis and mechanism is
submitted and under review.
Dehydration:
R-CH2-OH
Decarbonylation:
R-CHO
Water-gas shift:
CO + H2O
Gasification
Pyrolysis
Combustion
Char Gas
Bio-crude
Hot gas
cleanup
Pre-conditioning
Steam
reforming
Tar (steam)
reforming
R=CH + H2O
Upgrading
(HDO)
Syngas
R-H + CO
Electricity
Heat
Chemicals
CO2 + H2
Potential catalytic process
Fuels
6. Summary
Summary
•
The catalytic process was successfully used for 8 hours in real pyrolysis gas
converting heavy hydrocarbons to lighter ones.
•
A reduction in the amount of bio-crude of approximately 51 % could be
achieved in the tests.
•
The gas volume increased significantly after the conversion.
•
The composition of the pyrolysis oil also changed. For example, the amount of
oxygen was dramatically reduced after the conversion. Implying less
oxygenated compounds.
•
The combustion of the gas in the radiant tube burner displayed a changed
behaviour using the treated pyrolysis gas. The combustion started closer to
the burner nozzle, which means a longer flame.
•
The iron-based catalytic process has the potential as a pre-reformer step (prereformer concept) for bio-crude rich pyrolysis gas
•
The production of hydrogen from pyrolysis gas without hydrogen/steam
addition in atmospheric pressure seems to be a viable pathway for hydrogenrich gas production
•
Experiments with longer exposure time is necessary to investigate the lifetime
of the catalyst
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KTH collaborators and funding partners
Questions?