Catalytic Deoxygenation Reaction
Pathways for Bio-Oil Model
Compounds
Jonathan E. Peters
RTI International
Catalyst development strategy for in-situ catalytic
biomass pyrolysis with hydrogen
Objectives
•
Increase deoxygenation activity
•
Improve hydrogen utilization at low pressure
•
Maximize carbon recovery in liquid product
•
Fluidizable material
Process
Development
Catalyst
Development
Strategy
•
Use model compounds to test deoxygenation activity
•
Evaluate effect of different fluidizable supports
•
Screen catalysts at a range of reaction conditions
•
Determine reaction pathways to drive catalyst development
Scale-Up
Biofuel
Technology
Catalyst Descriptions
Support Type
Catalyst Name
Description
SA1
Alumina-based
SA1 – A
Alumina, low Ni loading
SA1 – B
Alumina, high Ni loading
SA2
Transition metal oxide
SA2 – A
Transition metal oxide, low Ni loading
SA2 – B
Transition metal oxide, high Ni loading
MMO1
Fe-based
MMO1 – A
Fe-based, low Ni loading
MMO1 – B
Fe-based, high Ni loading
Solid Acid
Mixed Metal Oxide
Automated Model
Compound Reactor
•
Programmed reduction, reaction,
and oxidation sequences for
unattended operation
•
Rapid screening to evaluate
deoxygenation activity with model
compounds at various conditions
•
Quantitative real-time product
analysis using RGA mass
spectrometer
•
Products correlated with specific
ions (m/z) to provide product
composition
Experimental Conditions
•
Heated Zone
Vaporizer
Hot Box Temp: up to 250°C
Pump
•
Reactor Temp: up to 550°C
Liquid Reactant
10% Ar/ N2 bal.
•
•
•
Pressure: 10 – 300 psig
Multiple carrier/feed gases: N2,
Argon, H2
Multiple reduction/oxidation gases:
N2, Air, H2
N2
Model Compounds Tested: Anisole
and Guaiacol
N2
MFC-2
10% Ar/ H2 bal.
MFC-1
10% Ar/ N2 bal.
MFC-1
MFC-3
Splitflow to RGA
Gas to Vent
Air
MFC-4
H2
•
Reactors
MFC-1
MFC-1
Condensers
Liquid
Peters, J. E., et al. Energy Fuels 2015
Analytical Methods – RGA Mass Spectrometer
100
Volume Percent (%)
Reaction Step
• 96% Conversion
• Complete deoxygenated
products early in reaction
• Less deoxygenated
products emerge later as
catalyst deactivates
• Oxygen removed as water
Oxidation
Reaction
10
1
0.1
0.01
215
235
Hydrogen
Carbon Dioxide
Toluene
Carbon Monoxide
255
Water
Argon
Phenol
Methane
275
295
Time On Stream (min)
Nitrogen
Guaiacol
Cresol
315
335
Oxygen
Benzene
He
Guaiacol deoxygenation over SA1, without hydrogen at
450°C, 10 psig, WHSV-1 = 4.3 h
Oxidation Step
• 50/50 mixture of air and N2
is used to oxidize the
carbon deposits (coke) on
catalyst
• CO2, CO, and water are
measured to quantify the
amount of coke formed
during the reaction
Previous Work - Guaiacol Deoxygenation over
Commercial Packed-Bed HDO Catalyst
100
80
80
60
60
40
40
20
20
0
0
Inert, 0% H2 Inert, 60% H2
A, 0% H2
Guaiacol Conversion (%)
Product Selectivity (wt%)
100
Coke
Methane
Cresol
Phenol
Toluene
Benzene
CO2
Water
Conv.
A, 60% H2
Peters, J. E., et al. Energy Fuels 2015
Product selectivity (wt% of product total) and conversion for hydrodeoxygenation of
guaiacol over inert material and Ni-based HDO catalyst (A), with and without hydrogen
at 350°C, 10 psig, WHSV-1 = 0.54 h
Experimental – Guaiacol deoxygenation over selected
catalysts
Reaction Variables
•
Screened 9 different catalysts (3 Ni loadings each
on 3 supports)
•
5 temperatures (300 – 500°C) with 60% hydrogen
•
3 temperature (400 – 500°C) without hydrogen
•
72 total experiments
Best Results
•
400°C with 60% hydrogen
•
good compromise of high guaiacol conversion
(>99%), less coke and methane production
HDO
Catalyst
In-situ
catalytic
pyrolysis
catalyst
Fluidized
Support
Results – Guaiacol deoxygenation over selected catalysts
at 400°C, with hydrogen
Product Selectivity (wt% of total products)
Catalyst
SA1
SA1 - A
SA1 - B
SA2
SA2 - A
SA2 - B
MMO1
MMO1 - A
MMO1 - B
Water Benzene Toluene Phenol Cresol Anisole Methylanisole Xylenol
13
7
15
10
12
13
11
13
14
6
7
2
2
2
2
6
16
22
3
5
2
2
2
2
0
2
6
18
24
32
33
36
35
56
37
25
14
11
14
12
20
20
3
4
4
5
8
3
1
2
3
7
10
13
8
6
4
8
9
8
6
6
7
16
23
15
2
11
14
0
0
0
CO Methane Coke Conv.
4
1
2
0
0
0
0
0
0
1
1
9
1
1
1
10
8
7
• Ni loading increases hydrogen utilization and decreases coke formation
12
8
3
29
5
2
1
2
1
53
72
97
27
94
99
99
99
99
Results – Guaiacol deoxygenation over selected catalysts
at 400°C, with hydrogen
Product Selectivity (wt% of total products)
Catalyst
SA1
SA1 - A
SA1 - B
SA2
SA2 - A
SA2 - B
MMO1
MMO1 - A
MMO1 - B
Water Benzene Toluene Phenol Cresol Anisole Methylanisole Xylenol
13
7
15
10
12
13
11
13
14
6
7
2
2
2
2
6
16
22
3
5
2
2
2
2
0
2
6
18
24
32
33
36
35
56
37
25
14
11
14
12
20
20
3
4
4
5
8
3
1
2
3
7
10
13
8
6
4
8
9
8
6
6
7
16
23
15
2
11
14
0
0
0
CO Methane Coke Conv.
4
1
2
0
0
0
0
0
0
1
1
9
1
1
1
10
8
7
• Solid acid catalysts produce more alkylated products and less
methane
12
8
3
29
5
2
1
2
1
53
72
97
27
94
99
99
99
99
Results – Guaiacol deoxygenation over selected catalysts
at 400°C, with hydrogen
Product Selectivity (wt% of total products)
Catalyst
SA1
SA1 - A
SA1 - B
SA2
SA2 - A
SA2 - B
MMO1
MMO1 - A
MMO1 - B
Water Benzene Toluene Phenol Cresol Anisole Methylanisole Xylenol
13
7
15
10
12
13
11
13
14
6
7
2
2
2
2
6
16
22
3
5
2
2
2
2
0
2
6
18
24
32
33
36
35
56
37
25
14
11
14
12
20
20
3
4
4
5
8
3
1
2
3
7
10
13
8
6
4
8
9
8
6
6
7
16
23
15
2
11
14
0
0
0
CO Methane Coke Conv.
4
1
2
0
0
0
0
0
0
• Ni loading increases deoxygenation activity on Mixed Metal
oxide catalyst but carbon is still lost to methane
1
1
9
1
1
1
10
8
7
12
8
3
29
5
2
1
2
1
53
72
97
27
94
99
99
99
99
Results – Guaiacol deoxygenation over selected catalysts
at 400°C, with hydrogen
• Higher Ni loading increases hydrogen utilization evident by greater
conversion and water production
• Solid acid catalysts increases carbon recovery in liquid product by
producing alkylated products: cresol, methylanisole, and xylenol
• Mixed metal oxide catalysts has good deoxygenation activity but
produces more methane
• Biomass pyrolysis results confirm that the greater carbon recovery
in the liquid product from SA2 results in an overall lower oxygen
content by weight and higher yields
Guaiacol Deoxygenation Reaction Pathways
1. Demethylation and
HDO, HDO
2. Transalkylation and
HDO, HDO
3. HDO, transalkylation,
HDO
4. HDO, transalkylation,
methylation, HDO
5. HDO, methylation,
methylation, HDO
Acknowledgements
Funding provided by DOE/EERE
• Award No. DE-EE0006636
Commercial Partners
• Jostein Gabrielsen
• Nadia Luciw Ammitzboll
RTI Contributors
• David Dayton (PI)
• John Carpenter
• Ofei Mante
• Kaige Wang
• Marty Lail
• David Barbee
• Gary Howe
• Martin Lee
Analytical Methods – RGA Mass Spectrometer
Component
Mole percent (mol %)
Selected m/z
Argon†
Nitrogen
Hydrogen
Oxygen
Carbon
Monoxide
Carbon Dioxide
Methane
10
76, 60, 30
14, 30, 60
10.5
20
14, 28, 29
1, 2
16, 32
3.333
12, 16
10
5.0
Guaiacol
0.5, 1.0, 1.5
Anisole
0.5, 1.0, 1.5
Benzene
Toluene
Phenol
Cresol
Water
Methylanisole
Xylenol
0.452
1.857
0.600
0.565
6.234
0.250
0.260
12, 16, 28, 29, 44
12, 13, 14, 15, 16, 17
12, 15, 77, 78, 79, 94, 107,
108, 124
12, 15, 78, 92, 93, 94, 107,
108
15, 77, 78
44, 91, 92, 94
94
44, 78, 107, 108
16, 17, 18
77, 79, 91, 107
77, 79, 91, 107
Real-time, online MS analysis
†internal
standard
• Products correlated with
specific ions (m/z)
• Products quantified by
calibration and integration
under curve
• Provides time resolved product
composition