Alternative Fuels Research: Practical
Applications and Foundational Questions
Ohio Center for Intelligent Propulsion and Advanced Life Management
Ohio Third Frontier Program Review
Heinz J. Robota, Ph.D.
Ohio Research Scholar in Alternative Fuels
Group Leader: Alternative Fuels Synthesis
University of Dayton Research Institute
University of Cincinnati
14 May 2013
Overview
•Alternative Fuels in Aviation
•Fuel types and specifications
•Facilities
• Practical Scale Preparations
• Fischer-Tropsch Synthetic Paraffinic Kerosene
•Unique “single carbon number, narrow boiling” fuels
•True “drop-in” renewable Jet-A
• Foundational Research
•Algae oil to jet and diesel
•Kinetics of stearic acid deoxygenation
•Summary
The Origination of the Assured Aerospace Fuels
Research Facility
Generate practical sample quantities of jet boiling range material
for evaluation and demonstration
Alternative Fuels Approved by “type”
for use in a blend with petroleum fuel
USAF leadership from properties, characteristics, specifications, through
flight approval – commercial aviation now implementing slowly
Approved or nearly approved fuels categorized as “Synthetic Paraffinic
Kerosene” (SPK)
Aliphatic hydrocarbons – negligible aromatic content
Highly isomerized alkanes – for low temperature properties
Type Specifications accommodate the peculiarities of the fuel chemical
constituents
Fischer-Tropsch SPK – First type to be approved
Hydrotreated Renewable Jet (HRJ) or Hydrotreated Esters and Fatty Acids
(HEFA) – second to be approved
Spec has added requirements related to: Gum, FAME content
Nearly approved Alcohol-to-Jet (ATJ) – allows higher cycloparaffins
Otherwise, these specs are the SAME
Shroyer Park Center Catalyst
Preparation and Testing Capabilities
4 Fixed bed reactors with
concurrent liquid and gaseous feed
2 Fixed bed FT synthesis reactors
and 2 CSTRs available for swap
Micromeritics ASAP 2020
textural analysis and
chemisorption analysis system
being installed
Continuous off-gas monitoring with
on-line GC
Surface Area
Pore Volume
Pore size distribution
Metal Catalyst dispersion
Mix-muller for 1-3 kg
preparation of extrudable
catalyst/binder aggregate
1” laboratory extruder for
making shaped catalyst for
use in AAFRF or other
practical-scale fixed bed
reactors reactors
High resolution FTIR with heated multi-path gas cell for trace gas
contaminant analysis – NH3, HCN, CO, CO2
Usable for condensed phase research as well
Facilities: Assured Aerospace Fuels
Research Facility - AAFRF
• What Is The AAFRF?
– SPU, Facility and Team
• Skilled and experience team (USAF,
UDRI and BMI)
– Answer practical questions about
fuels from alternative sources
– Producing practical quantities of
demonstration fuel for testing and
demonstrating synthetic routes
– Assess catalyst –related
technology through formulation
and evaluation. Lab at Shroyer
Park Center
AAFRF-SPU Designed with FT
Upgrading in Mind
AAFRF Commissioned making
SPK from Genuine F-T Wax
AAFRF SPK properties are nearly identical to other non JP-8
Validated design criteria
jet fuels
Validated catalyst function
Required Heat Trace everywhere
Distillation heater required higher
output than original design
Validated automation system
Ready for production research!
Preparing a C14 narrow boiling SPK:
Maximizing Isomer Yield
% Selectivity
100
basis crack
90
SPU crack
80
basis total
70
iso
60
SPU total
iso
50
basis multi
40
SPU multi
30
20
basis mono
10
0
0.40 0.50 0.60 0.70 0.80 0.90 1.00
Conversion
Fed roughly 2200 gal n-C14 - recovered 1700 gal of
mixed C14 isomers
Outstanding performance scalability
from lab to AAFRF scale
90
Time Behavior of n-tetradecane
conversion
crack
80
total
iso
multi
70
mono
60
conv
% Selcetivity
Comparing the Lab Basis with AAFRF-SPU
Performance in n-tetradecane isomerization
Synthetic approach demonstrated at
SPC Lab scale – in house catalysts
scaled to multi kg lots
50
40
30
20
10
0 100 200 300 400 500 600 700 800 9001000
Hours on Stream
Preparing a C14 narrow boiling SPK: Final
Product by Distillation
n-C14 can be sufficiently reduced by distillation
to meet Jet-A Freezing Point Specification
4
Normalized FID current
3.5
Isomerized tetradecane product
3
Distilled refined tetradecane
2.5
2
1.5
A consolidated 500 gal batch with
freezing point of -41.7 °C – meets
Jet-A Specification
Isomer distribution is different from
a solvent-dewaxed product in a
desirable way – multi-branched
isomers dominate
Distillation Gradient T90-T10 = 17 °C
– meets the narrow boiling target
1
0.5
0
6.5
7
7.5
From concept discussions to fuel
8
delivery in 18 months
Retention time (minutes)
A successful campaign and project!
Supporting Commercialization: Finishing a
Prospective True Renewable “Drop-in” Jet-A
1750 gallons of “CH
Crude” delivered for
Total Acid Number
(TAN) reduction and
separation of the Jet-A
Specification –compliant
fraction
Delivered TAN 140 mg/g
Required reduction to
<0.10 mg/g
Distilled fraction to meet
Jet-A Specification
Supporting Commercialization: Finishing a
Prospective True Renewable “Drop-in” Jet-A
Parameter, Requirements
J-1
J-2
J-3
J-4
J-5
J-6
J-7
-38.5(a)
-41
-45.1
-44.4
-43.1
-42
-46.2
0.004
0.004
0.002
0.002
0.004
0.002
0.006
Flash point, min. 38°C
52
45
37
43
42
46
46
Density at 15°C, 775–840 kg/m3
804
804
803
802
802
805
804
Freezing point, max. -40°C
Total Acid Number, max 0.1 mg KOH/g
max
Distillation temperature, °C
10 % recovered, max. 205°C
175
167
165
164
164
166
168
50 %
recovered(b)
208
204
201
200
201
203
201
90 %
recovered(b)
254
252
246
248
250
252
246
Final boiling point, max. 300°C
267
276
264
264
264
266
261
Distillation residue, max. 1.5%
1.2
1.2
1.2
1.2
1.3
1.0
1.1
Distillation loss, max. 1.5%
0.7
0.4
0.7
0.7
0.3
0.8
0.6
J-10
J-11
J-12
Cumulative(d)
Requirements
Freezing point, max. -40°C
J-8
J-9
-42.9
-43.4
-43.5
-43.4
-43.0
Total Acid Number, max 0.1 mg KOH/g
max
0.011
0.008
0.009
0.004
0.005
Flash point, min. 38°C
48
44
42
42
44
Density at 15°C, 775–840 kg/m3
808
806
805
803
804
175
168
162
163
167
recovered(b)
206
201
199
200
202
90 % recovered(b)
251
248
249
249
250
Final boiling point, max. 300°C
268
263
264
264
266
Distillation residue, max. 1.5%
1.0
1.1
1.3
1.2
1.2
Distillation loss, max. 1.5%
0.7
0.2
0.6
0.3
0.5
Delivered 525 gallons of a
theoretical 565 max, >90%
Cumulative TAN 0.005 mg
KOH/g – an effective overall
conversion of 99.996% !!
First use of a sulfided catalyst
in the system
Fuel met all applicable JET-A
specifications
Distillation temperature, °C
(c)
10 % recovered, max. 205°C
50 %
Flash point and Freezing point
set the bounds on allowable
composition
Converting Algal Oil to Fuels: First
to n-Alkanes
CH2-COOR1
|
CH -COOR2
|
CH2-COOR3
R1-COOH
3H2
R2-COOH
+
Algae provided by USAF
from Phycal production
CH3-CH2-CH3
Hydrogenolysis
C17H36
R3-COOH
Triglyceride
Pd/C + H2
Decarbonylation
Output of a Third Frontier
development program
C18H38
C17H35-COOH
Pd/C + H2
C17H35-CHO
Hydrodeoxyagenation
Hydrogenolysis
Pd/C + H2
Pd/C -/+ H2
Esterfication
C17H35-COOH
H2O
C17H35-CH2OH
Heat
Pd/C + H2
Reduction
C18H38
Processed ~ 2.5 L of algal oil
Product Alkanes reflect oil composition and a
changing catalyst selectivity with time-on-stream
n-C18
n-C17
n-C16
n-C15
n-alkane total
100
80
60
40
20
0
Mass % in Product
C18H37-COO-C17H35
Hydrogenation/
dehydrogenation
0
50
100
150
Time on Stream (hours)
200
Converting Algal Oil to Fuels: n-Alkanes
to Fuel
All methods and
catalysts used are
readily scalable
n-C17
n-C18
n-C15
Deoxygenated alkane mixture
hydro-converted to isomers and
cracked products with Pt/US-Y
n-C16
A Practical Diesel Fuel
Selective removal of n-alkanes
improves cold weather flow –
Arctic Grade Diesel Fuel
Elucidating Reaction Kinetics of a Complex
Reaction Network
C17H36
Pd/C + H2
Decarboxylation
Decarbonylation
C18H38
C17H35-CHO
C17H35-COOH
Pd/C + H2
Hydrogenolysis
Pd/C + H2
Pd/C -/+ H2
Esterfication
Hydrogenation/
dehydrogenation
C17H35-COOH
C17H35-COO-C18H37
C17H35-CH2OH
H2O
Heat
Pd/C + H2
C18H38
Rigorous control of all reaction
variables to produce reproducible
reaction rates allowing parameter
extraction
Reduction
Fitting power law kinetics with the
effects of T, concentration of reactants
Summary
•Established a laboratory infrastructure to make and investigate
fuel-making catalysts and catalyst processes
•Brought to operation the AAFRF-SPU within the design
envelope by making genuine Fischer-Tropsch SPK
•Successfully produced two unique research fuels for
composition-property research
•Delivered 525 gallons of genuine drop-in renewable Jet-A for an
industrial collaborator
•Established foundational research related to liquid fuel-making
catalytic chemsitries
Acknowledgements
This research was supported, in part, by the U. S. Air Force Cooperative Grant Numbers F33615-03-22347 and FA8650-10-2-2934 with Mr. Robert W. Morris Jr. serving as the Air Force Grant Monitor. The
research was also sponsored by the State of Ohio Subrecipient Award No. COEUS # 005909 to the
University of Dayton (Dr. Dilip Ballal as the Grant Monitor) under the “Center for Intelligent
Propulsion and Advanced Life Management,” program with the University of Cincinnati (Prime Award
NO. TECH 09-022). We gratefully acknowledge this support.
Thank you to UDRI personnel: Steve Zabarnick, Matthew de Witt, Rich Striebich, Linda Shafer, Ryan
Adams, Zachary West, Dave Thomas, Gordon Dieterle, James Shardo, Jerry Grieselhuber, Jeff
Coleman, Jeff Unroe, Alan Wendel, Dennis Davis, Ted Williams, David Gasper, Scott Breitfield,
Rhonda Cook, Zachary Sander, Jhoanna Alger, Andrew Palermo, Albert Vam, Roger Carr, Becki
Glagola, Sam Tanner, Drew Allen
Thank you to Battelle personnel: Satya Chauhan, Eric Griesenbrock, Nick Conkle, Grady Marcum, Bill
Jones, George Wrenn, Sarah Nejfelt, Cory Kuhnell, Stephen M. Howe, Erik Edwards, J. Boyce, C.
Lukuch
Thank you to Air Force Personnel: Robert W. Morris, Jr., Lt. Mark Roosz, Lt. Adam Parks, Milissa
Flake
Thank you to UTC Personnel: Jennifer Kelley, Steve Procuniar